CN109654249B

CN109654249B - Pinch valve

Info

Publication number: CN109654249B
Application number: CN201811565573.3A
Authority: CN
Inventors: 黄忠林; 许鑫; 熊建敏
Original assignee: Zhuhai Unicook Technology Co Ltd
Current assignee: Zhuhai Unicook Technology Co Ltd
Priority date: 2018-12-20
Filing date: 2018-12-20
Publication date: 2020-06-09
Anticipated expiration: 2038-12-20
Also published as: CN109654249A

Abstract

The invention provides a pinch valve comprising: a housing having a mounting passage for a flexible tube to pass through; the first iron core is arranged in the shell in a sliding mode; the second iron core is arranged in the shell in a sliding mode, the sliding track line of the first iron core is parallel to the sliding track line of the second iron core, and the second iron core is close to the flexible pipe compared with the first iron core; the second iron core resets the piece, and the second iron core resets the piece and cooperates with the second iron core to drive the second iron core to the direction motion of being close to the flexible pipe, the second iron core extrusion flexible pipe makes the flexible pipe keep closing. The invention solves the problem of small pressure resistance value of the electromagnetic pinch valve in the prior art.

Description

Pinch valve

Technical Field

The invention relates to the technical field of valves, in particular to a pinch valve.

Background

At present, the solenoid valve for blanking (such as soy sauce, water starch and the like) is generally to place a valve core and a spring in a flow channel, or to replace an elastic element such as the spring with a permanent magnet, and to provide a sealing force by the spring or the force of the permanent magnet to promote the sealing of the solenoid valve. For the solenoid valve of the type, the valve core and the spring are arranged in the flow channel, so that the flow resistance of the solenoid valve is increased, residues are easy to cause, the solenoid valve is only suitable for gas and liquid media, and the valve core is easy to jam and cannot work normally when a solid and a liquid-solid mixture exist. For the catering industry, the residual means nourishing bacteria, which affects safety and sanitation, and the unsmooth means that the working requirement cannot be met.

Aiming at the problems of residue, jamming and the like, the current better proposal adopts a form of a pinch valve. Pinch valves are divided into two types, pneumatic and electromagnetic pinch valves. The pneumatic pinch valve needs to be provided with an air source, occupies a large space and has limitation in use.

For an electromagnetic pinch valve, a common type in the market at present is an externally-matched pipeline, for example, a pipe is clamped to complete sealing of a flow passage, the pressure resistance value of the valve is only 0.06Mpa through actual measurement, the stroke is also only 2.5mm, and the pipe diameter and the pressure resistance value of the pinch valve far cannot meet the use requirements. In order to meet the requirements of the electromagnetic pinch valve with a large caliber and high pressure resistance, the electromagnetic force of the electromagnetic valve needs to be improved, and the stroke needs to be increased. The stroke is increased, and simultaneously, the air gap magnetic resistance of the electromagnetic valve is increased, so that the electromagnetic force is sharply reduced. Therefore, the electromagnetic valve needs to ensure equivalent electromagnetic force while increasing the stroke, and the number of turns of the coil and the size of magnetic conduction parts, such as the size of a framework, a valve core and other parts of the valve body, are also increased, so that the overall size of the electromagnetic valve is increased, more design space is occupied, and the cost is increased.

Disclosure of Invention

The invention mainly aims to provide a pinch valve to solve the problem that the pressure resistance value of an electromagnetic pinch valve in the prior art is small.

In order to achieve the above object, the present invention provides a pinch valve comprising: a housing having a mounting passage for a flexible tube to pass through; the first iron core is arranged in the shell in a sliding mode; the second iron core is arranged in the shell in a sliding mode, the sliding track line of the first iron core is parallel to the sliding track line of the second iron core, and the second iron core is close to the flexible pipe compared with the first iron core; the second iron core resets the piece, and the second iron core resets the piece and cooperates with the second iron core to drive the second iron core to the direction motion of being close to the flexible pipe, the second iron core extrusion flexible pipe makes the flexible pipe keep closing.

Furthermore, the pinch valve further comprises a coil assembly, one part of the coil assembly is wound on the outer side of the first iron core to drive the first iron core to move towards the direction far away from the flexible pipe, and the other part of the coil assembly is wound on the outer side of the second iron core to drive the second iron core to move towards the direction far away from the flexible pipe, so that the flexible pipe is loosened, and the flexible pipe is opened.

Further, the coil assembly comprises a first coil and a second coil, the first coil and the second coil are wound on the outer sides of the first iron core and the second iron core respectively, the pinch valve further comprises a control piece, the control piece is connected with the first coil and the second coil, the second coil and the first coil are controlled to be started in sequence, the control piece controls the second coil to be electrified, the second coil drives the second iron core to move towards the direction far away from the flexible pipe and is attached to the first iron core, then the control piece controls the first coil to be electrified, the first iron core and the second iron core move towards the direction far away from the flexible pipe in a common direction, and the flexible pipe is loosened.

Further, the two parts of the coil assembly are simultaneously electrified and simultaneously drive the first iron core and the second iron core to move towards the direction far away from the flexible pipe so as to loosen the flexible pipe.

Further, the first iron core is provided with a first inclined surface, the second iron core is provided with a second inclined surface, and the first inclined surface and the second inclined surface can be attached or separated.

Further, the first inclined surface and/or the second inclined surface are inclined in a direction away from the flexible pipe to a direction close to the axis of the first iron core.

Furthermore, one end of the first iron core, which is close to the second iron core, is conical, and the conical shape of the first iron core is provided with a first inclined plane; and/or one end of the second iron core close to the first iron core is conical, and the second iron core is conical and provided with a second inclined plane.

Further, an included angle is formed between the first inclined surface and/or the second inclined surface and the sliding track line of the first iron core, and the included angle is larger than 0 degree and smaller than 90 degrees.

Further, the included angle is 45 degrees.

Further, along the sliding track line of the first iron core, the inner ring of the shell is provided with an expanding section and a reducing section which are connected in sequence, a limiting step is formed between the expanding section and the reducing section, the first iron core is arranged on the expanding section in a sliding mode, the second iron core is arranged on the reducing section, and the first iron core can be matched with the limiting step in a stopping mode so that the second iron core is separated from the first iron core under the action of the second iron core resetting piece.

Further, pinch valve still includes that first iron core resets, and the both ends that first iron core resets respectively with first iron core and shell butt for first iron core provides the power that resets to the direction motion that is close to the flexible tube.

Further, the second iron core resets and is the permanent magnet, and the permanent magnet setting is in the outside that the second iron core is close to the one end of flexible pipe.

Further, the pinch valve further comprises a magnetic isolation piece, and the magnetic isolation piece is arranged between the permanent magnet and the second iron core.

Furthermore, the pinch valve further comprises a magnetic conduction piece, the magnetic conduction piece is overlapped with the permanent magnet along the sliding track line of the second iron core, and the magnetic conduction piece is close to the flexible pipe.

Further, the housing includes: the coil component comprises a framework, a first iron core and a second iron core, wherein the framework is provided with an accommodating cavity and a groove, the accommodating cavity is used for accommodating the first iron core and the second iron core, the groove is used for accommodating the coil component and is at least one, and the section of the framework with the groove is a magnet isolation body; the shell is sleeved on the outer side of the framework to shield the groove; the valve seat is connected with the framework and provided with an installation channel, and the installation channel is communicated with the accommodating cavity; the lid, the lid is established at the opening part that holds the chamber to shelter from and hold the chamber.

By applying the technical scheme of the invention, the strokes of the first iron core and the second iron core can be mutually overlapped by setting the double iron cores, so that the clamping force of the flexible pipe which can be clamped by the pinch valve is increased, the diameter of the flexible pipe which can be clamped by the pinch valve is increased, and the pressure resistance value of the pinch valve is improved. Under the normal condition, the second iron core presss from both sides tight flexible pipe under the effect that the second iron core reset, makes the pinch valve be in the state of closing, and when needs unblock, the second iron core is in the direction motion of keeping away from the flexible pipe, and the second iron core is in the same place with the laminating of first iron core, and first iron core and second iron core move to the direction of keeping away from the flexible pipe, thereby loosen the flexible pipe, and the flexible pipe is opened. The arrangement mode enables the strokes of the first iron core and the second iron core to be mutually overlapped, the pressure resistance value of the pinch valve pinch tube is improved, the radius of the pinch tube is enlarged, effective clamping of a flexible tube with a large tube diameter is realized, the integral volume of the pinch valve is not influenced, the practicability of the pinch valve is improved, and meanwhile, the pinch valve has the advantages of no residue, low cost, simple structure, small volume, equipment space saving and the like.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 shows a schematic of the pinch valve of the present invention in a closed configuration;

FIG. 2 shows a schematic view of the pinch valve of FIG. 1 in an open configuration;

FIG. 3 shows an exploded view of the pinch valve of FIG. 1;

FIG. 4 shows a schematic structural view of the skeleton of the pinch valve of FIG. 3;

FIG. 5 shows a schematic view of the first coil of the pinch valve of FIG. 1 when energized; and

FIG. 6 shows a schematic diagram of the configuration of the pinch valve of FIG. 1 with the first and second coils energized.

Wherein the figures include the following reference numerals:

11. a limiting step; 12. a framework; 121. an accommodating chamber; 122. a groove; 13. a housing; 14. a valve seat; 15. a cover body; 20. a flexible tube; 30. a first iron core; 31. a first inclined plane; 40. a second iron core; 41. a second inclined plane; 50. a second core reset piece; 61. a first coil; 62. a second coil; 70. a first core reset member; 80. a magnetic shield; 90. a magnetic conduction member.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present invention, unless specified to the contrary, use of the terms of orientation such as "upper, lower, top, bottom" or the like, generally refer to the orientation as shown in the drawings, or to the component itself in a vertical, perpendicular, or gravitational orientation; likewise, for ease of understanding and description, "inner and outer" refer to the inner and outer relative to the profile of the components themselves, but the above directional words are not intended to limit the invention.

The invention provides a pinch valve, aiming at solving the problem that the pressure resistance value of an electromagnetic pinch valve in the prior art is small.

A pinch valve as shown in fig. 1 to 3, comprising a housing having a mounting passage through which a flexible tube 20 passes, a first plunger 30, a second plunger 40 and a second plunger return 50; the first iron core 30 is slidably arranged in the shell; the second iron core 40 is arranged in the shell in a sliding mode, the sliding track line of the first iron core 30 is parallel to the sliding track line of the second iron core 40, and the second iron core 40 is close to the flexible tube 20 compared with the first iron core 30; the second plunger returning element 50 is engaged with the second plunger 40 and drives the second plunger 40 to move toward the flexible tube 20, and the second plunger 40 presses the flexible tube 20 to keep the flexible tube 20 closed.

In the present embodiment, by providing the double iron cores, the strokes of the first iron core 30 and the second iron core 40 can be overlapped with each other, so as to increase the clamping force of the flexible tube 20 that can be clamped by the pinch valve, increase the diameter of the flexible tube 20 that can be clamped by the pinch valve, and improve the pressure resistance value of the pinch valve. Under the normal state, the second iron core 40 clamps the flexible tube 20 under the effect of the second iron core resetting piece 50, so that the pinch valve is in the closed state, when the tube needs to be unlocked, the second iron core 40 moves towards the direction away from the flexible tube 20, the second iron core 40 is attached to the first iron core 30, the first iron core 30 and the second iron core 40 move towards the direction away from the flexible tube 20, the flexible tube 20 is loosened, and the flexible tube 20 is opened. The arrangement mode enables the strokes of the first iron core 30 and the second iron core 40 to be mutually superposed, the pressure resistance value of the pinch valve pinch tube is improved, the radius of the pinch tube is enlarged, the flexible tube 20 with a large tube diameter is effectively clamped, the integral volume of the pinch valve is not affected, the practicability of the pinch valve is improved, and meanwhile, the pinch valve has the advantages of no residue, low cost, simple structure, small volume, equipment space saving and the like.

In this embodiment, the pinch valve further includes a coil assembly, a portion of the coil assembly is wound around the outside of the first plunger 30 to drive the first plunger 30 to move away from the flexible tube 20, and another portion of the coil assembly is wound around the outside of the second plunger 40 to drive the second plunger 40 to move away from the flexible tube 20 to loosen the flexible tube 20 and open the flexible tube 20.

Specifically, the coil assembly comprises a first coil 61 and a second coil 62, the first coil 61 and the second coil 62 are respectively wound on the outer sides of the first iron core 30 and the second iron core 40, and the pinch valve further comprises a control part which is connected with the first coil 61 and the second coil 62 and controls the second coil 62 and the first coil 61 to be sequentially started. The driving time and sequence of the first coil 61 and the second coil 62 are controlled by the control element, when the coil assembly is not electrified, a gap is formed between the first iron core 30 and the second iron core 40, the first iron core 30 and the second iron core 40 are not jointed, when the pinch valve is unlocked, the second coil 62 is firstly controlled by the control element to be electrified, as shown in figure 5, the second coil 62 drives the second iron core 40 to move in the direction away from the flexible pipe 20, the second iron core 40 approaches until contacting the first iron core 30 and is jointed with the first iron core 30, at the moment, the first coil 61 is then controlled by the control element to be electrified, as shown in figure 6, the first coil 61 drives the first iron core 30 to move, the first iron core 30 and the second iron core 40 are combined into a whole, the first iron core 30 and the second iron core 40 move in a time-sharing and segmented mode, so that the stroke of the first iron core 30 and the second iron core 40 is enlarged, the air gap resistance is reduced, the starting force of the iron cores is ensured, the stroke of the pinch valve for clamping the tube is doubled.

Of course, the first coil 61 and the second coil 62 may also be energized simultaneously, that is, the two parts of the coil assembly are energized simultaneously, and simultaneously drive the first iron core 30 and the second iron core 40 to move away from the flexible tube 20 to loosen the flexible tube 20, because the first iron core 30 needs to overcome the elastic force of the linear spring when moving, the moving stroke of the first iron core 30 is smaller than that of the second iron core 40, and therefore the air gap resistance generated between the first iron core 30 and the second iron core 40 is still smaller than that to be overcome by the same single-iron-core single-coil moving stroke. In addition, except that first coil 61 and second coil 62 set up each other independently, can also communicate first coil 61 and second coil 62 and become a whole, can break-make simultaneously, convenient control.

In the present embodiment, the first iron core 30 has a first inclined surface 31, the second iron core 40 has a second inclined surface 41, the first inclined surface 31 and the second inclined surface 41 can be attached to or detached from each other, and the first inclined surface 31 and/or the second inclined surface 41 are inclined in a direction approaching the axis of the first iron core 30 in a direction away from the flexible tube 20.

Specifically, the first iron core 30 and the second iron core 40 are both cylindrical, the sliding directions of the first iron core 30 and the second iron core 40 are perpendicular to the axial direction of the flexible tube 20, one ends of the first iron core 30 and the second iron core 40, which are close to each other, are tapered, a first inclined surface 31 and a second inclined surface 41 are formed in the tapered shape, the air gap magnetic resistance between the first iron core 30 and the second iron core 40 is smaller through the first inclined surface 31 and the second inclined surface 41, after the first iron core 30 and the second iron core 40 are combined, the gap between the two is small, and the air gap magnetic resistance between the two combined surfaces can be ignored. In the time period that the control part controls the two coils to be sequentially driven, the air gap magnetic resistance between the first iron core 30 and the second iron core 40 is not interfered with each other, the magnetic resistance of each iron core is equivalent to that of the existing single iron core electromagnetic valve, the starting force of the iron cores is ensured, and the radius of the pinch tube of the pinch valve is enlarged due to the superposition of the strokes of the first iron core 30 and the second iron core 40. Therefore, the pinch valve structure with double iron cores and double coils has a large stroke and equivalent electromagnetic starting force, and meets the requirements on large caliber and high pressure resistance.

Optionally, the first inclined surface 31 and/or the second inclined surface 41 form an included angle with the sliding track line of the first iron core 30, and the included angle is greater than 0 degree and less than 90 degrees.

Preferably, the included angle is 45 degrees.

In this embodiment, the pinch valve further includes a first iron core resetting member 70, the first iron core resetting member 70 is a linear spring, and two ends of the first iron core resetting member 70 are respectively abutted against one end of the first iron core 30 far away from the second iron core 40 and the housing, so as to provide a resetting force to the direction close to the flexible tube 20 for the first iron core 30.

In this embodiment, along the sliding trajectory of the first iron core 30, the inner ring of the housing has an expanding section and a reducing section which are connected in sequence, a limiting step 11 is formed between the expanding section and the reducing section, the first iron core 30 is slidably disposed on the expanding section, the second iron core 40 is disposed on the reducing section, when the coil assembly is de-energized, the second iron core 40 extrudes the flexible tube 20 under the action of the second iron core resetting member 50, the first iron core 30 abuts against the limiting step 11 under the action of the first iron core resetting member 70, and the first iron core 30 is matched with the limiting step 11 in a stopping manner, so that the second iron core 40 is separated from the first iron core 30 under the action of the second iron core resetting member 50.

In this embodiment, the second core resetting member 50 is a permanent magnet, and the permanent magnet is disposed outside one end of the second core 40 close to the flexible tube 20. The permanent magnet is annular and is sleeved on the outer side of the section of the second iron core 40 close to the flexible pipe 20, so that the permanent magnet can adsorb the second iron core 40 when the coil assembly is powered off, and the second iron core 40 can clamp the flexible pipe 20. The end surface of the permanent magnet of the present embodiment that faces away from the flexible tube 20 is an N-pole, and the end surface that faces the flexible tube 20 is an S-pole.

Optionally, the pinch valve further comprises a magnetism isolating piece 80, and the magnetism isolating piece 80 is arranged between the inner ring of the permanent magnet and the second iron core 40, so that the permanent magnet and the second iron core 40 are prevented from being seriously contacted and abraded, and the service life is prolonged.

Further optionally, the pinch valve further comprises a magnetic conductor 90, along the sliding trajectory of the second plunger 40, the magnetic conductor 90 overlaps the permanent magnet, and the magnetic conductor 90 is close to the flexible tube 20, so that the magnetic force of the permanent magnet can act on the second plunger 40 more effectively.

In this embodiment, one end of the second plunger 40 close to the flexible tube 20 is a plate-shaped structure, and the plate-shaped structure presses the flexible tube 20 and closes the flexible tube 20, so that the pressing surface of the second plunger 40 pressing the flexible tube 20 is reduced, which is beneficial to increasing the degree of pressing the flexible tube 20.

In this embodiment, the housing includes a frame 12, a housing 13, a valve seat 14, and a cover 15, the frame 12 has an accommodating cavity 121 and two grooves 122, as shown in fig. 4, the accommodating cavity 121 is used for accommodating the first core 30 and the second core 40, the two grooves 122 are used for accommodating the coil assembly, a segment of the frame 12 having the groove 122 is a magnetism isolating body, and the rest is a magnetism conducting body; the shell 13 is in a sleeve shape and is sleeved outside the framework 12 to shield the groove 122; the valve seat 14 is connected with the end of the framework 12, the valve seat 14 is provided with a mounting channel, the valve seat 14 is a T-shaped tee joint so that the mounting channel is communicated with the accommodating cavity 121, after the flexible pipe 20 passes through the mounting channel, two ends of the flexible pipe are fixed on the valve seat 14 through locking joints, the position of the valve seat 14, which is far away from the second iron core 40, is open, a clamping plate is arranged at the open position, one part of the clamping plate extends into the valve seat 14, the clamping plate and the plate-shaped structure of the second iron core 40 clamp the flexible pipe 20 together, when the second iron core 40 moves towards the direction close to the flexible pipe 20, the distance between the second iron core 40 and the clamping plate is reduced, so that the flexible pipe 20 is clamped, and when the second iron core 40 moves towards the direction far away from the flexible pipe 20, the distance between the second iron core 40 and the; the cover body 15 covers the opening of the accommodating chamber 121 to shield the accommodating chamber 121.

In this embodiment, an end of the first iron core 30 away from the second iron core 40 is also tapered, accordingly, an end of the cover 15 extending into the accommodating cavity 121 has a tapered recess, the first iron core 30 and the cover 15 are also in bevel fit, and the effect of the bevel fit is similar to that of the bevel fit between the first iron core 30 and the second iron core 40, and when the first iron core 30 and the second iron core 40 are attached together, the air gap magnetic resistance of the movement of the two is the air gap magnetic resistance between the cover 15 and the first iron core 30. In this way, the inclined surface fit between the first core 30 and the second core 40 and the inclined surface fit between the first core 30 and the cover 15 achieve the purpose of increasing the stroke when the valve core stroke is limited.

It should be noted that the second iron core 40 needs to move upward against the magnetic force of the permanent magnet when the pinch valve is opened, and the first iron core 30 only serves as a magnetic conductor of the second iron core 40, so the number of turns of the second coil 62 is properly larger than that of the first coil 61 when the coil is designed, and the stroke of the first iron core 30 and the second iron core 40 is also the same, and the stroke of the second iron core 40 is properly smaller than that of the first iron core 30 when the coil is designed.

In addition, when designing the coil, the number of turns of the coil of the first coil 61 and the second coil 62 and the stroke of the first iron core 30 and the second iron core 40 may be adjusted appropriately, and they are not necessarily equal to each other, according to different product requirements. For solenoid valves or solenoid pinch valves requiring a larger stroke, the number of cores and coils can also be increased appropriately, i.e., a multi-core and multi-coil configuration.

It should be noted that, a plurality in the above embodiments means at least two.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

1. the problem of small pressure resistance value of the electromagnetic pinch valve in the prior art is solved;

2. the radius of the clamping pipe of the pipe clamping valve is enlarged, and the effective clamping of the flexible pipe with large pipe diameter is realized;

3. the starting force of the iron core is ensured by adopting a mode of time sharing, segmentation and non-interference of magnetic resistance;

4. no residue, low cost, simple structure, small volume and equipment space saving.

It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A pinch valve, comprising:

a housing having a mounting passage for a flexible tube (20) to pass through;

a first core (30), the first core (30) being slidably disposed within the housing;

the second iron core (40) is arranged in the shell in a sliding mode, the sliding track line of the first iron core (30) is parallel to the sliding track line of the second iron core (40), the second iron core (40) is close to the flexible tube (20) compared with the first iron core (30), relative movement exists between the second iron core (40) and the first iron core (30), and the second iron core (40) can move towards the direction close to the first iron core (30) and can move together after being attached with the first iron core (30);

the second iron core resetting piece (50) is matched with the second iron core (40) and drives the second iron core (40) to move towards the direction close to the flexible pipe (20), and the second iron core (40) extrudes the flexible pipe (20) to enable the flexible pipe (20) to be kept closed.

2. Pinch valve according to claim 1, characterized in that it further comprises a coil assembly, one part of which is wound around the outside of the first plunger (30) to drive the first plunger (30) in a direction away from the flexible tube (20), and another part of which is wound around the outside of the second plunger (40) to drive the second plunger (40) in a direction away from the flexible tube (20) to loosen the flexible tube (20) and open the flexible tube (20).

3. The pinch valve according to claim 2, wherein the coil assembly comprises a first coil (61) and a second coil (62), the first coil (61) and the second coil (62) are respectively wound on the outer sides of the first core (30) and the second core (40), the pinch valve further comprises a control member, the control member is connected with the first coil (61) and the second coil (62) and controls the second coil (62) and the first coil (61) to be sequentially activated, the control member controls the second coil (62) to be electrified, the second coil (62) drives the second core (40) to move in a direction away from the flexible tube (20) and is attached to the first core (30), and then the control member controls the first coil (61) to be electrified, and the first core (30) and the second core (40) to move together in a direction away from the flexible tube (20), to loosen the flexible tube (20).

4. Pinch valve according to claim 2, characterized in that both parts of the coil assembly are energized simultaneously and drive the first plunger (30) and the second plunger (40) simultaneously in a direction away from the flexible tube (20) to loosen the flexible tube (20).

5. Pinch valve according to claim 1, characterized in that the first core (30) has a first bevel (31) and the second core (40) has a second bevel (41), the first bevel (31) and the second bevel (41) being able to abut or be separated.

6. Pinch valve according to claim 5, characterized in that the first ramp (31) and/or the second ramp (41) is inclined in a direction closer to the axis of the first core (30) in a direction away from the flexible tube (20).

7. The pinch valve of claim 5,

one end of the first iron core (30) close to the second iron core (40) is conical, and the conical shape of the first iron core (30) is provided with the first inclined plane (31); and/or

One end, close to the first iron core (30), of the second iron core (40) is conical, and the second inclined plane (41) is formed in the conical shape of the second iron core (40).

8. Pinch valve according to claim 5, characterized in that the first ramp (31) and/or the second ramp (41) form an angle with the sliding trajectory of the first core (30), which angle is larger than 0 degrees and smaller than 90 degrees.

9. The pinch valve of claim 8, wherein the included angle is 45 degrees.

10. Pinch valve according to claim 1, characterized in that along the sliding trajectory of the first core (30), the inner ring of the housing has a diameter-expanding section and a diameter-reducing section connected in series, a limiting step (11) being formed between the diameter-expanding section and the diameter-reducing section, the first core (30) being slidingly arranged on the diameter-expanding section, the second core (40) being arranged on the diameter-reducing section, the first core (30) being able to cooperate with a stop of the limiting step (11) in order to separate the second core (40) from the first core (30) under the action of the second core reset element (50).

11. The pinch valve according to claim 1, further comprising a first plunger return (70), wherein both ends of the first plunger return (70) abut against the first plunger (30) and the housing, respectively, providing the first plunger (30) with a return force moving in a direction approaching the flexible tube (20).

12. Pinch valve according to claim 1, characterized in that the second plunger return (50) is a permanent magnet arranged outside the end of the second plunger (40) close to the flexible tube (20).

13. Pinch valve according to claim 12, characterized in that it further comprises a magnetic separator (80), said magnetic separator (80) being arranged between the permanent magnet and the second core (40).

14. Pinch valve according to claim 12, characterized in that it further comprises a magnetic conductor (90), along the sliding trajectory of the second core (40), said magnetic conductor (90) being superposed with the permanent magnets and said magnetic conductor (90) being close to the flexible tube (20).

15. The pinch valve of claim 2, wherein the housing comprises:

a bobbin (12), the bobbin (12) having a receiving cavity (121) and a groove (122), the receiving cavity (121) being used for receiving the first iron core (30) and the second iron core (40), the groove (122) being used for receiving the coil assembly and being at least one, and the section of the bobbin (12) having the groove (122) being a magnet;

the shell (13), the shell (13) is sleeved on the outer side of the framework (12) to shield the groove (122);

a valve seat (14), wherein the valve seat (14) is connected with the framework (12), the valve seat (14) is provided with the installation channel, and the installation channel is communicated with the accommodating cavity (121);

the cover body (15) is arranged at the opening of the accommodating cavity (121) in a covering mode, and the accommodating cavity (121) is shielded.