CN209270966U - A kind of air water two-way hydraulic control back-flushing filter - Google Patents

Abstract

The utility model provides a kind of air water two-way hydraulic control back-flushing filter, including filter body, and be provided thereon the inlet being sequentially communicated, the recoil chamber of pollution discharge joint is installed, strainer chamber, the liquid outlet of net-filter assembly are installed, pollution discharge joint includes: the first valve chamber led to during blowdown valve body has, and it is respectively arranged at the inlet and sewage draining exit at the first valve chamber both ends, the length direction of blowdown valve body is equipped with the filtering mouth being connected to respectively with the first valve chamber and strainer chamber；Blowdown spool, it is slidably mounted in the first valve chamber, with under the driving of feed liquor active force to sewage draining exit direction mobile, the feed liquor position to close sewage draining exit and be connected to strainer chamber with inlet, and to the movement of inlet direction, the waste removal position to close inlet and be connected to strainer chamber with sewage draining exit under the driving of backwash liquid active force.By the way that a pollution discharge joint is arranged, that is, it is able to achieve the control to inlet and sewage draining exit, compared with prior art, structure is simple, and production cost is low.

Description

A kind of air water two-way hydraulic control back-flushing filter

Technical field

The utility model relates to coal mine back purge system technical fields, and in particular to a kind of air water two-way hydraulic control flushing-back filtering Device.

Background technique

The working media used in coal mine hydraulic supporting system is emulsion, can not since underground coal mine condition is more severe Avoid that there are impurity, if cannot clear out in time impurity, in system normal operation, impurity can pollute other hydraulic members Part, to cause the operation of hydraulic system part ineffective, out of control, or even damage.

Currently, mainly realizing feed liquor using electromagnetic priority valve or manual operation reversal valve in impurity backwash process Mouthful, liquid outlet and recoil mouth open or close, in backwash, it is desirable that inlet and liquid outlet are closed, and sewage draining exit is opened；When Impurity turns off sewage draining exit after sewage draining exit discharge, opens inlet and liquid outlet.But using the defect of electromagnetic priority valve Be: for safety of mining, electromagnetic priority valve needs mating intrinsically safe circuit and intrinsic safety electric source, and input cost is larger, and electromagnetism is first Pilot valve itself contamination resistance is lower, has biggish limitation in common fully-mechanized mining working use；And use manual operation commutation Valve, operator need to carry out the switching of reversal valve by handle, and complex for operation step, working efficiency is low.

To solve the above-mentioned problems, Chinese patent literature CN102258898B discloses a kind of automatic backwash time liquid filtering Device, including inlet, liquid outlet, sewage draining exit, filter core, recoil valve and blowdown valve, recoil valve include recoil short tube, recoil room, spray Mouth, recoil part, closure plate；In backwash, backwash liquid is entered by the short tube that recoils into recoil room, pushes recoil part by nozzle, So that two closure plates block inlet and liquid outlet respectively；Meanwhile backwash liquid is entered in filter chamber by recoil room by recoil catheter Recoil tube, filter core is then sprayed to by multiple recoil holes high pressure on recoil tube wall, and push filter core high speed rotation, due to filter The high speed rotation of core makes the sundries in filter core mesh be thrown away by thorough throwing；In addition, automatically turning on blowdown under the action of high pressure Valve will filter out the impurity come and all be discharged from the mudhole of blowdown valve, after the completion of blowdown, reply of two closure plates in spring Power effect is lower while automatically turning on inlet and liquid outlet, and sewage draining exit is automatically closed in blowdown valve.

Although above-mentioned technical proposal solves that hand-operated direction valve is cumbersome and the high technology of electromagnetic priority valve input cost Problem, but there are still following defects: inlet and sewage draining exit are to control it by recoil valve and blowdown valve to open or close respectively It closes, structure is complicated, increases production cost；In addition, since blowdown valve is just to open blowdown under the backwash liquid effect of high pressure Mouthful, and if high pressure feed flow is also taken in maloperation in normal feed flow, blowdown valve can also be opened, and liquid can be discharged from sewage draining exit, Cause normally return liquid, reliability is lower.

Utility model content

Therefore, the technical problem to be solved by the present invention is to overcome automatic backwash in the prior art to return liquid filtering Structure is complicated for device, the technological deficiency of high production cost, to provide, a kind of structure is simple, production cost is low, the gas of high reliablity Water two-way hydraulic control back-flushing filter.

For this purpose, the utility model provides a kind of air water two-way hydraulic control back-flushing filter, including filter body, and setting In on the filter body the inlet being sequentially communicated, the recoil chamber for being equipped with pollution discharge joint, net-filter assembly is installed Strainer chamber, liquid outlet, the pollution discharge joint include:

Blowdown valve body, have in lead to the first valve chamber, and be respectively arranged at first valve chamber both ends inlet and Sewage draining exit, the length direction of the blowdown valve body are equipped with the filtering being connected to respectively with first valve chamber and the strainer chamber Mouthful；

Blowdown spool is slidably mounted in first valve chamber, is had under the driving of feed liquor active force to described The movement of sewage draining exit direction, the feed liquor position to close the sewage draining exit and be connected to the strainer chamber with the inlet, and To the inlet direction movement, to close the inlet and make the strainer chamber and institute under the driving of backwash liquid active force State the waste removal position of sewage draining exit connection.

As a preferred embodiment, the side of blowdown spool towards the inlet is formed connects with the inlet The bottom of logical admission chamber, the admission chamber is provided with first through hole；

The blowdown spool at the feed liquor position, the first through hole be connected with the filtering mouth so that it is described into Liquid mouth is connected to the strainer chamber；

In waste removal position, the first through hole and the filtering mouth disconnect the blowdown spool, the sewage draining exit and institute State the connection of strainer chamber.

As a preferred embodiment, the blowdown spool has the first segment for being movably installed in first valve chamber, and The second segment of the first valve chamber setting is stretched out, the diameter of the second segment is greater than the diameter of the first segment, outside to be formed The step of protrusion, the step with it is described state blowdown valve body protrude into it is described recoil chamber end be oppositely arranged；

The blowdown spool at feed liquor position, the step and the blowdown valve body protrude into the recoil chamber end, The inner wall of the recoil chamber and the outer wall three of the first segment are enclosed accommodating cavity, and the accommodating cavity passes through the second recoil Channel is connected to recoil mouth.

As a preferred embodiment, it is additionally provided with the first bias piece between the blowdown spool and the filter body, First bias piece is used to apply the biasing force for keeping it mobile to the sewage draining exit direction to the blowdown spool.

It as a preferred embodiment, further include replacing chamber, the friendship with what the recoil mouth, liquid outlet, strainer chamber were connected to For the intracavitary alternate tabs being provided with for controlling the recoil mouth and the liquid outlet open and-shut mode.

As a preferred embodiment, the alternate tabs include:

Alternately valve body, have in the second valve chamber for leading to, the upper end of second valve chamber connects institute by the first recoil channel Recoil mouth is stated, lower end connects liquid outlet, and its side is connected to the strainer chamber；

Alternately spool, is slidably mounted in second valve chamber, and one end far from the recoil mouth is provided with the Two bias pieces, the alternately spool, which has, to abut under the active force of second bias piece with cover for seat, to close the recoil Mouth and the feed liquor position for being connected to the strainer chamber with the liquid outlet, and to described under the driving in backwash liquid active force The movement of liquid outlet direction, the waste removal position to close the liquid outlet and be connected to the strainer chamber with the recoil mouth.

As a preferred embodiment, the end of the alternately spool towards the recoil mouth is arranged in circular platform type.This is practical New technique scheme, has the advantages that

1. air water two-way hydraulic control back-flushing filter provided by the utility model, in normal feed flow, blowdown spool can be Sewage draining exit is closed under the driving of feed liquor active force, and is connected to strainer chamber with inlet, and when backwashing impurity, blowdown spool exists Inlet is closed under the driving of backwash liquid active force, and is connected to strainer chamber with sewage draining exit, by the way that a pollution discharge joint is arranged, i.e., It is able to achieve the control to inlet and sewage draining exit, compared with prior art, structure is simple, and production cost is low, and above-mentioned blowdown connects The structure setting of head makes even if in the case where maloperation high pressure feed flow, and sewage draining exit will not be opened, and reliability is higher.

2. air water two-way hydraulic control back-flushing filter provided by the utility model, blowdown spool is formed towards the side of inlet There is the admission chamber being connected to inlet, the bottom of admission chamber is provided with first through hole；For blowdown spool at feed liquor position, first is logical Hole is connected with filtering mouth so that inlet and strainer chamber are connected to；Blowdown spool is in waste removal position, first through hole and filtering mouth It disconnects, sewage draining exit is connected to strainer chamber, moves left and right the company's through and off realized first through hole and filter mouth by blowdown spool It opens, above-mentioned blowdown spool has the advantage simple in structure.

3. air water two-way hydraulic control back-flushing filter provided by the utility model, blowdown spool at feed liquor position, step with The outer wall three that blowdown valve body protrudes into the end of recoil chamber, the inner wall of recoil chamber and first segment is enclosed accommodating cavity, accommodates Chamber is connected to by the second recoil channel with recoil mouth；In backwash, backwash liquid enters accommodating cavity by the second recoil channel, instead Fliud flushing makes blowdown spool be moved to waste removal position by driving step, closes inlet, above-mentioned blowdown spool, accommodating cavity Simple with the structure setting in the second recoil channel, production cost is low.

4. air water two-way hydraulic control back-flushing filter provided by the utility model, also sets between blowdown spool and filter body It is equipped with the first bias piece, the first bias piece is used to apply the biasing force for keeping it mobile to sewage draining exit direction, recoil to blowdown spool When washing, high pressure backwash liquid driving blowdown spool is fast moved to inlet direction, and the first bias piece can buffer blowdown spool Impact force between filter body extends the service life of blowdown spool.

5. air water two-way hydraulic control back-flushing filter provided by the utility model, alternately spool is slidably mounted on the second valve In chamber, one end far from recoil mouth is provided with the second bias piece, alternately spool have under the active force of the second bias piece with Cover for seat abutting, the feed liquor position to close recoil mouth and be connected to strainer chamber with liquid outlet, and in backwash liquid active force Waste removal position mobile to liquid outlet direction under driving, to close liquid outlet and be connected to strainer chamber with the mouth that recoils.Pass through alternating Spool moves up and down, and realizes that control recoil mouth has structure simply excellent with the open and-shut mode of liquid outlet on the contrary, replacing spool Point.

6. air water two-way hydraulic control back-flushing filter provided by the utility model, alternately spool is towards the end of recoil mouth in circle Bench-type setting enters strainer chamber along the inclined-plane of alternately spool front end to be conducive to backwash liquid, slows down high pressure backwash liquid to friendship For the impact force of spool, the service life of alternately spool is extended.

Detailed description of the invention

It, below will be right in order to illustrate more clearly of specific embodiment of the present invention or technical solution in the prior art Specific embodiment or attached drawing needed to be used in the description of the prior art are briefly described, it should be apparent that, it is described below In attached drawing be that some embodiments of the utility model are not paying creativeness for those of ordinary skill in the art Under the premise of labour, it is also possible to obtain other drawings based on these drawings.

Fig. 1 is structural schematic diagram of the air water two-way hydraulic control back-flushing filter of the utility model when normally for liquid status；

Fig. 2 is the enlarged structure schematic diagram of part A in Fig. 1；

Fig. 3 is the enlarged structure schematic diagram of part B in Fig. 1；

Fig. 4 is structural schematic diagram of the air water two-way hydraulic control back-flushing filter in backwashing state；

Fig. 5 is the enlarged structure schematic diagram of C portion in Fig. 4；

Fig. 6 is the enlarged structure schematic diagram of the part D in Fig. 4.

Description of symbols: 1, filter body；11, inlet；12, recoil chamber；13, strainer chamber；14, alternating chamber；15, Liquid outlet；16, recoil mouth；161, the first recoil channel；162, the second recoil channel；17, sewage draining exit；2, blowdown valve body；21, One valve chamber；22, accommodating cavity；23, mouth is filtered；3, blowdown spool；31, first segment；32, second segment；321, step；33, admission chamber； 34, first through hole；35, the first bias piece；4, alternating valve body；41, the second valve chamber；42, alternating spool；43, the second bias piece； 44, cover for seat.

Specific embodiment

The technical solution of the utility model is clearly and completely described below in conjunction with attached drawing, it is clear that described Embodiment is the utility model a part of the embodiment, instead of all the embodiments.Based on the embodiments of the present invention, originally Field those of ordinary skill every other embodiment obtained without making creative work belongs to practical Novel protected range.

It is in the description of the present invention, it should be noted that term " center ", "upper", "lower", "left", "right", " perpendicular Directly ", the orientation or positional relationship of the instructions such as "horizontal", "inner", "outside" is to be based on the orientation or positional relationship shown in the drawings, and is only For ease of description the utility model and simplify description, rather than the device or element of indication or suggestion meaning must have it is specific Orientation, be constructed and operated in a specific orientation, therefore should not be understood as limiting the present invention.In addition, term " the One ", " second ", " third " are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance.

In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, term " is pacified Dress ", " connected ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or integrally Connection；It can be mechanical connection, be also possible to be electrically connected；Can be directly connected, can also indirectly connected through an intermediary, It can be the connection inside two elements.For the ordinary skill in the art, above-mentioned art can be understood with concrete condition The concrete meaning of language in the present invention.

In addition, as long as technical characteristic involved in the utility model different embodiments disclosed below is each other Not constituting conflict can be combined with each other.

Embodiment

The present embodiment provides a kind of air water two-way hydraulic control back-flushing filters, as shown in figs. 1 and 4, including filter body 1, And it is set to the inlet 11 being sequentially communicated, the recoil chamber 12 for being equipped with pollution discharge joint, installation on the filter body 1 Have strainer chamber 13, the liquid outlet 15 of net-filter assembly, the pollution discharge joint includes: blowdown valve body 2, have in lead to the first valve chamber 21, and it is respectively arranged at the inlet 11 and sewage draining exit 17 at 21 both ends of the first valve chamber, the length side of the blowdown valve body 2 It is equipped with the filtering mouth 23 being connected to respectively with first valve chamber 21 and the strainer chamber 13 upwards；Blowdown spool 3, movably pacifies Loaded in first valve chamber 21, have under the driving of feed liquor active force it is mobile to 17 direction of sewage draining exit, to close The feed liquor position stated sewage draining exit 17 and be connected to the strainer chamber 13 with the inlet 11, and the drive in backwash liquid active force To 11 direction of the inlet movement, to close the inlet 11 and connect the strainer chamber 13 with the sewage draining exit 17 under dynamic Logical waste removal position.The air water two-way hydraulic control back-flushing filter of the present embodiment is able to achieve pair by the way that a pollution discharge joint is arranged The control of inlet 11 and sewage draining exit 17, compared with prior art, structure is simple, and production cost is low, and above-mentioned pollution discharge joint Structure setting makes even if in the case where maloperation high pressure feed flow, and sewage draining exit 17 will not be opened, and reliability is higher.

The side of the blowdown spool 3 towards the inlet 11 forms the admission chamber being connected to the inlet 11 33, the bottom of the admission chamber 33 is provided with several first through hole 34；The blowdown spool 3 is in the feed liquor position shown in Fig. 2 When setting, the first through hole 34 is connected with the filtering mouth 23 so that the inlet 11 and the strainer chamber 13 connection；Institute When stating blowdown 3 waste removal position shown in Fig. 4 of spool, the first through hole 34 is disconnected with the filtering mouth 23, the sewage draining exit 17 are connected to the strainer chamber 13.By the connection and disconnection of the mobile realization first through hole 34 of blowdown spool 3 and filtering mouth 23, Above-mentioned blowdown spool has the advantage simple in structure.

As shown in figures 2 and 5, the blowdown spool 3 has the first segment 31 for being movably installed in first valve chamber 21, and The second segment 32 that first valve chamber 21 is arranged is stretched out, the diameter of the second segment 32 is greater than the diameter of the first segment 31, with Form the step 321 that outwardly protrudes, the step 321 states blowdown valve body 2 to protrude into the recoil end of chamber 12 opposite with described Setting；For the blowdown spool 3 at feed liquor position, the step 321 protrudes into the end of the recoil chamber 12 with the blowdown valve body 2 The outer wall three in portion, the inner wall of the recoil chamber 12 and the first segment 31 is enclosed accommodating cavity 22, the accommodating cavity 22 It is connected to by the second recoil channel 162 with recoil mouth 16.In backwash, backwash liquid is entered by the second recoil channel 162 and is held Chamber 22 is set, backwash liquid makes blowdown spool 3 be moved to waste removal position by driving step 321, closes inlet 11, above-mentioned The structure setting of blowdown spool 3, accommodating cavity 22 and the second recoil channel 162 is simple, and production cost is low.

The spring as the first bias piece 35 is additionally provided between the blowdown spool 3 and the filter body 1, it is described First bias piece 35 is used to apply the biasing force for keeping it mobile to 17 direction of sewage draining exit to the blowdown spool 3.Described One bias piece 35 puts aside energy when the blowdown spool 3 is moved to the waste removal position from the feed liquor position, in the row Dirty spool 3 releases energy when being moved to the feed liquor position from the waste removal position, and when backwash, high pressure backwash liquid drives blowdown Spool 3 is fast moved to 11 direction of inlet, and the first bias piece 35 can buffer between blowdown spool 3 and filter body 1 Impact force, extend the service life of blowdown spool 3.

Further include replacing chamber 14 with what the recoil mouth 16, liquid outlet 15, strainer chamber 13 were connected to, is set in the alternately chamber 14 It is equipped with the alternate tabs for controlling the recoil mouth 16 and 15 open and-shut mode of the liquid outlet.

As shown in figs. 3 and 6, the alternate tabs include: alternately valve body 4, have in lead to the second valve chamber 41, described second The upper end of valve chamber 41 connects the recoil mouth 16 by the first recoil channel 161, and lower end connects liquid outlet 15, and its side and institute State the connection of strainer chamber 13；Alternately spool 42, is slidably mounted in second valve chamber 41, far from the recoil mouth 16 One end is provided with the spring as the second bias piece 43, and the alternately spool 42 has the active force in second bias piece 43 It is abutted with cover for seat 44 down, the feed liquor position to close the recoil mouth 16 and be connected to the strainer chamber 13 with the liquid outlet 15 It sets, and to 15 direction of the liquid outlet movement, to close the liquid outlet 15 and make under the driving in backwash liquid active force The waste removal position that the strainer chamber 13 is connected to the recoil mouth 16.By moving up and down for alternately spool 42, realize that control is anti- 16 are blurted out with the open and-shut mode of liquid outlet 15 on the contrary, replacing spool has the advantages that structure is simple.

It is described alternately spool 42 towards it is described recoil mouth 16 end in circular platform type setting, thus be conducive to backwash liquid along Alternately the inclined-plane of 42 front end of spool enters strainer chamber 13, slows down high pressure backwash liquid to the impact force of alternately spool 42, extends friendship For the service life of spool.

In the present embodiment, inlet 11, recoil chamber 12, strainer chamber 13, alternately chamber 14, liquid outlet 15 there are two, feed liquor The medium of mouth 11 can be gas or liquid, when the medium of two inlets 11 is gas and liquid respectively, go out liquid from two The gases and liquid of 15 outflow of mouth are mixed to form spraying.

Certainly, the present utility model application does not do specific limit to the concrete form of the first bias piece 35 and the second bias piece 43 System, in other embodiments, the first bias piece 35 and the second bias piece 43 can also be the energy storage components such as water-proof rubber piece.

The working principle of the air water two-way back-flushing filter of the present embodiment is as follows:

When normal feed flow:

Blowdown spool 3 moves to feed liquor position shown in Fig. 2 under feed liquor active force, and alternately spool 42 is in the second bias piece 43 active force is located at feed liquor position shown in Fig. 3, and liquid is through inlet 11 through the admission chamber 33 of blowdown spool 3, first through hole 34, enter strainer chamber 13 after filtering mouth 23, then after net-filter assembly filters, flowed out through alternately valve body 4, from liquid outlet 15.

When backwash:

Backwash liquid separately flows into the second recoil channel 162 and the first recoil channel 161, the second recoil channel through recoil mouth 16 After backwash liquid in 162 flows into accommodating cavity 22, backwash liquid overcomes the effect power drive blowdown valve core 3 of the first bias piece 35 to be moved to Waste removal position shown in fig. 5 closes inlet 11, and is connected to strainer chamber 13 with sewage draining exit 17；In first recoil channel 161 Backwash liquid overcomes the effect power drive alternate valve core 42 of the second bias piece 43 to be moved to waste removal position shown in fig. 6, closes out liquid Mouth 15, and it is connected to strainer chamber 13 with recoil mouth 16, backwash liquid enters from the lower end of strainer chamber 13, miscellaneous in counter-flushing filter-net component After matter, it is discharged from the upper end of strainer chamber 13, then through sewage draining exit 17.

Obviously, the above embodiments are merely examples for clarifying the description, and does not limit the embodiments.It is right For those of ordinary skill in the art, can also make on the basis of the above description it is other it is various forms of variation or It changes.There is no necessity and possibility to exhaust all the enbodiments.And it is extended from this it is obvious variation or It changes among the protection scope created still in the utility model.

Claims (7)

1. a kind of air water two-way hydraulic control back-flushing filter, including filter body (1), and it is set to the filter body (1) inlet (11) being sequentially communicated on is equipped with the recoil chamber (12) of pollution discharge joint, is equipped with the strainer chamber of net-filter assembly (13), liquid outlet (15), it is characterised in that: the pollution discharge joint includes:

Blowdown valve body (2), have in lead to the first valve chamber (21), and be respectively arranged at the first valve chamber (21) both ends into Liquid mouth (11) and sewage draining exit (17), the length direction of the blowdown valve body (2) be equipped with respectively with first valve chamber (21) and The filtering mouth (23) of strainer chamber (13) connection；

Blowdown spool (3) is slidably mounted in first valve chamber (21), is had under the driving of feed liquor active force to institute State the movement of sewage draining exit (17) direction, to close the sewage draining exit (17) and make the strainer chamber (13) and the inlet (11) even Logical feed liquor position, and under the driving of backwash liquid active force it is mobile to the inlet (11) direction, with close it is described into Liquid mouth (11) and the waste removal position for being connected to the strainer chamber (13) with the sewage draining exit (17).

2. air water two-way hydraulic control back-flushing filter according to claim 1, it is characterised in that: blowdown spool (3) court The admission chamber (33) being connected to the inlet (11) is formed to the side of the inlet (11), the admission chamber (33) Bottom is provided with first through hole (34)；

The blowdown spool (3) at the feed liquor position, the first through hole (34) be connected with the filtering mouth (23) with It is connected to the inlet (11) with the strainer chamber (13)；

In waste removal position, the first through hole (34) and the filtering mouth (23) disconnect the blowdown spool (3), the blowdown Mouth (17) is connected to the strainer chamber (13).

3. air water two-way hydraulic control back-flushing filter according to claim 1 or 2, it is characterised in that: the blowdown spool (3) With the first segment (31) for being movably installed in first valve chamber (21), and stretch out the second of the first valve chamber (21) setting Section (32), the diameter of the second segment (32) are greater than the diameter of the first segment (31), to form the step outwardly protruded (321), the step (321) with it is described state blowdown valve body (2) protrude into it is described recoil chamber (12) end be oppositely arranged；

For the blowdown spool (3) at feed liquor position, the step (321) and the blowdown valve body (2) protrude into the recoil chamber (12) end, the inner wall of recoil chamber (12) and the outer wall three of the first segment (31) is enclosed accommodating cavity (22), the accommodating cavity (22) is connected to by the second recoil channel (162) with recoil mouth (16).

4. air water two-way hydraulic control back-flushing filter according to claim 3, it is characterised in that: the blowdown spool (3) with It is additionally provided with the first bias piece (35) between the filter body (1), first bias piece (35) is used for the blowdown Spool (3) applies the biasing force for keeping it mobile to the sewage draining exit (17) direction.

5. air water two-way hydraulic control back-flushing filter according to claim 4, it is characterised in that: further include and the recoil mouth (16), the alternating chamber (14) that liquid outlet (15), strainer chamber (13) are connected to is provided with described for controlling in alternately chamber (14) The alternate tabs of recoil mouth (16) and the liquid outlet (15) open and-shut mode.

6. air water two-way hydraulic control back-flushing filter according to claim 5, it is characterised in that: the alternate tabs include:

Alternately valve body (4), the upper end of the second valve chamber (41) led in having, second valve chamber (41) passes through the first recoil channel (161) the recoil mouth (16) is connected, lower end connects liquid outlet (15), and its side is connected to the strainer chamber (13)；

Alternately spool (42), it is slidably mounted in second valve chamber (41), one end far from recoil mouth (16) Be provided with the second bias piece (43), it is described alternately spool (42) have under the active force of second bias piece (43) with cover for seat (44) it abuts, the feed liquor position to close recoil mouth (16) and be connected to the strainer chamber (13) with the liquid outlet (15) It sets, and to the movement of the liquid outlet (15) direction, to close the liquid outlet (15) under the driving in backwash liquid active force And the waste removal position for being connected to the strainer chamber (13) with recoil mouth (16).

7. air water two-way hydraulic control back-flushing filter according to claim 6, it is characterised in that: described alternately spool (42) court It is arranged to the end of recoil mouth (16) in circular platform type.