CN209244496U - With specific length than, the piston of weight ratio and drill bit supporting structure and impactor - Google Patents

Abstract

The utility model relates to than, the piston of weight ratio and drill bit supporting structure and impactor, be connected with outer tube in the rear joint with specific length；The internal sleeve of the outer tube is equipped with inner casing, and there is distribution bar in the inside of the inner casing by rear joint location and installation, and the inside cavity of the distribution bar is equipped with non-return valve, is equipped with spring in the inside cavity of non-return valve；Piston is installed, one end of the piston is matched with the inner wall of inner casing, and the other end is matched with the guide sleeve being mounted on inside outer tube inside the outer tube；The end of the outer tube is equipped with front connector, and the end face location and installation that the front connector and guide sleeve match has snap ring；The inside of the front connector is slidably installed by snap ring limit drill bit.The ratio of the overall length L1 of the overall length L2 and drill bit of the piston are as follows: 1-1.35；The weight ratio of the piston and drill bit are as follows: 1-1.35.The conversion that impact energy is realized in maximum magnitude, substantially increases target efficiency.

Description

With specific length than, the piston of weight ratio and drill bit supporting structure and impactor

Technical field

The utility model relates to a kind of pneumatic impact equipment components, especially a kind of to have specific length ratio, weight ratio Piston and drill bit supporting structure and impactor.

Background technique

Valveless type down-the-hole air hammer is a kind of typical pneumatic impact equipment, it is the drilling tool of down-the-hole drill, is drilling machine reality Apply the operating mechanism of drilling.This equipment is mainly used for Drilling diameter 65-305mm, hole depth 60m driling explosion hole.Obviously, one The drilling efficiency of down-the-hole drill depends greatly on the performance of impactor.

Currently, the valveless down-the-hole air hammer used in the market is mainly to be produced by Sandvik rice Shengong department, Sweden Mission series piston-guide-sleeve-type valveless single-cylinder structure down-the-hole air hammer, as described in Figure 9, Mission series valve free impacter It is made of 16 parts, the rear joint 1 with API screw thread is the parts that impactor is connect with drilling rod；Non-return valve 2 is to prevent magma Water flows into the check valve of impactor and drilling rod；Lateral pin 5 is distribution bar 8 and the parts that check valve seat 3, rear joint 1 connect；Check Valve seat 3 can also introduce compressed air into distribution bar 8, realize matching for piston motion together with cylinder body 7, distribution bar 8, piston 9 It is pneumatic to make.The elongated shape piston 9 for being provided with central duct and side hole is that the energy of compressed air is directly converted to mechanical movement to move One part of energy, and this kinetic energy is passed to drill bit 16 by way of collision by it, so piston is one very crucial Part；Part 7 is that inside and outside cylinder is integrated the cylinder body of structure；Part 10 is retainer ring, it can prevent from living in more bit change 16 Plug skids off cylinder body；Part 13 is then to prevent drill bit 16 from falling off to open form snap ring；Part 11 has been the guide sleeve of distribution effect；Part 15 It is to drive drill bit rotation and the front connector in upper sliding；Part 16 is columnar drill body, is directly to contact to carry out broken rock with rock mass Tool.

The common following disadvantage of above-mentioned down-the-hole air hammer or city head: due to being all using independent between piston and drill bit Structure design, research was not done to the length of the two and weight proportion, so that the target efficiency of impactor is always It can not break through, optimal impact effect of arriving, so that impact energy conversion is unable to get maximization, cause the damage of impact energy It loses.

Furthermore:

1, distribution bar, valve seat and rear joint are rigidly connected with lateral pin mode, and lateral pin early stage, which is easily deformed, to be even broken, and with The pin hole requirement on machining accuracy that lateral pin matches sum is high, and cooperation precision is not easy to guarantee, handling are inconvenient.

2, distribution bar is longer, and is provided with the biggish injection well of area, is worked using ralocatable mode, is easy to appear early fracture Phenomenon, reliability when reducing impactor work.

3, there is more intake and exhaust road, thus cause biggish atmospheric pressure lost.

4, more distribution duct is provided on piston, air flue is transferred and distance is long, and pressure loss is big, makes it to heat treatment Reaction is sensitive, and stress is concentrated, and works often because of the reason early damage in process and structure.

Utility model content

The technical problem to be solved by the utility model is to provide a kind of pistons and brill with specific length than, weight ratio Head supporting structure and impactor are designed between the piston and drill bit of this impactor using matched length and weight proportion, in turn The conversion that impact energy is realized in maximum magnitude, substantially increases target efficiency.

In order to realize above-mentioned technical characteristic, purpose of the utility model is realized as follows: a kind of have specific length Than, the piston of weight ratio and drill bit supporting structure, the ratio of the overall length L1 of the overall length L2 and drill bit of the piston are as follows: 1-1.35； The weight ratio of the piston and drill bit are as follows: 1-1.35.

The ratio of the overall length L1 of the overall length L2 and drill bit of the piston are as follows: 1.15-1.30.

The weight ratio of the piston and drill bit are as follows: 1.05-1.20.

The ratio of the overall length L1 of the overall length L2 and drill bit of the piston are as follows: 1.18.

The weight ratio of the piston and drill bit are as follows: 1.06.

Using described in any one with specific length than, the impactor of the piston of weight ratio and drill bit supporting structure, it Including rear joint, outer tube is connected in the rear joint；The internal sleeve of the outer tube is equipped with inner casing, and the interior cylinder interior has By the distribution bar of rear joint location and installation, the inside cavity of the distribution bar is equipped with non-return valve, in the cavity of non-return valve Portion is equipped with spring；Piston is installed, one end of the piston is matched with the inner wall of inner casing, with work inside the outer tube Its other end of the movement of plug can be slidably matched with the guide sleeve being mounted on inside outer tube；Before the end of the outer tube is equipped with The end face location and installation that connector, the front connector and guide sleeve match has snap ring；The inside of the front connector is limited by snap ring Position is slidably installed and has drill bit, and the impact end surface of the drill bit and the end face of piston are engaged, and transmit impact energy；

The outer tube is internally provided with the annular housing A and annular housing B, the annular housing A of two different pore sizes Internal diameter be less than the internal diameter of annular housing B, the outer circle of the maximum outside diameter of the annular housing A and piston cooperates；The annular chamber The cooperation of the both ends of body B and inner casing.

The outer circle of the inner casing is equipped with orientational cone-shaped surface, and the orientational cone-shaped surface is matched with the conical surface of outer tube；The distribution The middle part of bar is equipped with support level, and the support level dress is matched with the stepped hole of inner casing；The large end face of the rear joint is logical The precession for matching screw thread with outer tube is crossed, the large end face of distribution bar is pressed abd fixed on to the end face of inner casing, makes rear joint, distribution Bar, inner casing and outer tube constitute rigid connection；The valve seat and distribution bar of the non-return valve use integral structure.

The inside of the piston has only drilled through centre bore, and gas channel was machined on the outer wall of piston；The difference of piston The diameter of axle between use arc transition.

Tapered face, positioning tapered face phase of the tapered face with processing on outer sleeve inner wall are machined on the guide sleeve Cooperation, and then guide sleeve is positioned.

The position matched on the distribution bar with inner casing is equipped with the second O-ring.

The position that the outer tube and rear joint match is equipped with the first O-ring；The snap ring uses subdivision structure, institute The outer circle for stating snap ring is equipped with third O-ring.

The utility model provides the shortcomings that a kind of double intracavity outer tube impactors effectively overcome existing impactor, in structure On carried out major transformation, in contrast have the advantage that

1, the transmitting of impact piston and drill bit impact energy maximizes

It is analyzed by analog simulation and Experimental Comparison, by the length between piston and drill bit than being limited centainly with weight ratio In value range, ensure that the conversion of optimal impact energy, that is, while improving frequency of impact, it is reasonable match piston with The length of the bit and weight enable piston impact power and stress transfer to realize and maximize, is higher in certain ratio range Effect.

2, distribution bar, inner casing, rear joint and outer tube trim designs are reasonable

On the one hand, inner casing outer circle is equipped with orientational cone-shaped surface e and matches with the conical surface d of outer tube, and support is equipped in the middle part of distribution bar Step, and matched with the stepped hole of inner casing one end；Another side, rear joint large end face is with the rotation for matching screw thread with outer tube Into directly the large end face of compression distribution bar promotes distribution bar, inner casing, rear joint and outer tube four on the large end face of inner casing Part constitutes rigid connection, jumping when avoiding the work of distribution bar by above structure, and holding that can be permanent is high-precision Cooperation, provides working efficiency.

3, distribution rod structure is reasonable

Distribution bar is an integral structure with valve seat, and distribution bar reduces diameters of axle ratio, easy to process, not variable at work Shape and fracture effectively reduce the loss of energy, improve target efficiency so that gas distribution channels are succinctly unobstructed.

4, piston structure is reasonable

Firstly, internal piston is only machined with centre bore, drilling number is few, diameter of axle variation is smaller, can more smoothly transmit punching Stress when device work is hit, its working life is extended；Secondly, on piston duct it is few, without duct of turning back, without elongated hole, processing It is convenient, it is high in machining efficiency, without carrying out highly difficult deep Hole.

5, bicavate outer tube designs, and air distribution efficiency is high

Housing tube cavity is equipped with two apertures different annular housing A and annular housing B, and the internal diameter of annular housing A is small In the internal diameter of annular housing B, the annular housing A cooperates with the major diameter of piston and the outer circle of guide sleeve respectively；The annular chamber The cooperation of the both ends of body B and inner casing, which increases effectively impact piston work area, so that compressed gas utilization rate mentions significantly Height, and then air distribution efficiency is improved, while ensure that target efficiency, improve energy transformation ratio.

6, guide sleeve and the design of housing tube positioning structure are reasonable

Guide sleeve is equipped with tapered face and matches with the tapered face of the positioning of outer tube, so that outer tube processing is more convenient, and And dimensional accuracy is easy to control, reduce difficulty of processing.

7, the design of system gas circuit is reasonable

System gas circuit is unobstructed, without Zigzag type gas circuit, greatly improves pneumatic efficiency, reduces atmospheric pressure lost.

Detailed description of the invention

The utility model is described in further detail with reference to the accompanying drawings and examples.

Fig. 1 is double intracavity outer tube impactor main sectional views of the utility model.

Fig. 2 is L partial enlarged view in Fig. 1 of the utility model.

Fig. 3 is S partial enlarged view in Fig. 1 of the utility model.

Fig. 4 is the partial enlarged view of H1 in Fig. 1 of the utility model.

Fig. 5 is the partial enlarged view of H2 in Fig. 1 of the utility model.

Working state figure when Fig. 6 is double intracavity outer tube impactor strokes of the utility model.

Working state figure when Fig. 7 is double intracavity outer tube impactor shadoofs of the utility model.

Fig. 8 is the DHD series anury pipe bit structure chart used joined together by the utility model.

Fig. 9 is existing Mission series valve free impacter main sectional view.

In figure: rear joint 1, non-return valve 2, the first O-ring 3, spring 4, distribution bar 5, the second O-ring 6, inner casing 7, piston 8, Outer tube 9, guide sleeve 10, third O-ring 11, snap ring 12, front connector 13, drill bit 14；

Tapered face a, the tapered face b of positioning, orientational cone-shaped surface e, conical surface d；

C~K is gas circuit.

Specific embodiment

The embodiments of the present invention is described further with reference to the accompanying drawing.

Embodiment 1:

Such as Fig. 1-8, it is a kind of with specific length than, the piston of weight ratio and drill bit supporting structure, the piston 8 it is total The ratio of the overall length L1 of long L2 and drill bit 14 are as follows: 1-1.35；The weight ratio of the piston 8 and drill bit 14 are as follows: 1-1.35.By adopting With the piston and drill bit of above structure, length and weight ratio, enable to piston impact energy power and stress transfer to realize It maximizes, is more efficient.

Embodiment 2:

It is a kind of with specific length than, the piston of weight ratio and drill bit supporting structure, the overall length L2 of the piston 8 and bore The ratio of first 14 overall length L1 are as follows: 1.15-1.30.When the weight ratio of piston 8 and drill bit 14 is within the scope of optimum ratio, length When than for 1.15-1.30, in the course of work, optimal impact energy changing effect can be obtained.

Embodiment 3:

It is a kind of with specific length than, the piston of weight ratio and drill bit supporting structure, the weight of the piston 8 and drill bit 14 Measure ratio are as follows: 1.05-1.20.When the length of piston 8 and drill bit 14 ratio is within the scope of optimum ratio, weight ratio 1.05-1.20 When, in the course of work, optimal impact energy changing effect can be obtained.

Embodiment 4:

It is a kind of with specific length than, the piston of weight ratio and drill bit supporting structure, the overall length L2 of the piston 8 and bore The ratio of first 14 overall length L1 are as follows: 1.18.When the weight ratio of piston 8 and drill bit 14 is within the scope of optimum ratio, length ratio is When 1.18, in the course of work, optimal impact energy changing effect can be obtained.

Embodiment 5:

It is a kind of with specific length than, the piston of weight ratio and drill bit supporting structure, the weight of the piston 8 and drill bit 14 Measure ratio are as follows: 1.06.When the length of piston 8 and drill bit 14 ratio is within the scope of optimum ratio, and weight ratio is 1.06, the course of work In, optimal impact energy changing effect can be obtained.

Embodiment 6:

Pass through the comparison of the length between the piston and drill bit to the utility model and the value range that varies in weight, wherein All impactors are all 5 cun of impactor structure unitary variant performance comparison numbers under medium ground (f8 grades of granite) operating condition According to obtaining following test result:

Table 1: the unitary variant performance comparison data of piston and drill bit under the conditions of different length and weight ratio

By test result, test data is obtained in Comprehensive Correlation table 1:

First, preferably piston and drill bit weight ratio are as follows: 1.05-1.20, piston and the length of the bit ratio are as follows: 1.15-1.30；

Second, preferably cooperation DHD series anury pipe bit, piston and drill bit weight ratio are as follows: 1.06, piston and the length of the bit Than are as follows: 1.18；Wherein DHD series anury pipe bit is as described in Figure 8.

Embodiment 7:

Using the step bicavate outer sleeve structure impactor of piston described in claim any one and drill bit, it includes Rear joint 1 is connected with outer tube 9 in the rear joint 1；The internal sleeve of the outer tube 9 be equipped with inner casing 7, the inner casing 7 it is interior There is distribution bar 5 in portion by 1 location and installation of rear joint, and the inside cavity of the distribution bar 5 is equipped with non-return valve 2, in non-return valve 2 Inside cavity is equipped with spring 4；Piston 8, one end of the piston 8 and the inner wall phase of inner casing 7 are installed inside the outer tube 9 Cooperation, as its other end of movement of piston 8 is slidably matched with the composition of guide sleeve 10 being mounted on inside outer tube 9；It is described outer The end of casing 9 is equipped with front connector 13, and the end face location and installation that the front connector 13 and guide sleeve 10 match has snap ring 12；The inside of the front connector 13 is slidably installed by the limit of snap ring 12 drill bit 14, the impact end surface of the drill bit 14 It is engaged with the end face of piston 8, and transmits impact energy.The impactor of above structure is relative to existing impactor, and zero Number of packages has measured reduction, is simplified its structure, ensure that the reliability of work, effectively extends its service life, Its target efficiency is made to have obtained good raising simultaneously.

Further, the outer circle of the inner casing 7 is equipped with orientational cone-shaped surface e, the conical surface d of the orientational cone-shaped surface e and outer tube 9 It matches；The middle part of the distribution bar 5 is equipped with support level, and the support level dress is matched with the stepped hole of inner casing 7；Institute The large end face of rear joint 1 is stated by matching the precession of screw thread with outer tube 9, including the large end face of distribution bar 5 is fixed The end face of cylinder 7 makes rear joint 1, distribution bar 5, inner casing 7 and outer tube 9 constitute rigid connection.By above-mentioned assembling structure, keep away Exempt from jumping when distribution bar 5 works, and the high-precision cooperation of holding that can be permanent, provides working efficiency.And then effectively Solve traditional impactor distribution bar, valve seat and rear joint be rigidly connected with lateral pin mode, lateral pin early stage be easily deformed very To the defect of fracture, and the defect that handling are inconvenient.

Further, the valve seat of the non-return valve 2 and distribution bar 5 use integral structure, the diameter of axle of the distribution bar 5 Than reducing.It is effectively avoided by above-mentioned diameters of axle ratio distribution bar 5 and is easy to appear early fracture phenomenon, improve impactor work When reliability.

Further, the inside of the piston 8 has only drilled through centre bore, and gas channel was machined on the outer wall of piston 8； The diameter of axle variation of piston 8 is small, and arc transition is used between the different diameters of axle.The piston 8 of this structure is easy to process, processing efficiency Height, without carrying out highly difficult deep Hole.

Further, the outer tube 9 is internally provided with the annular housing A and annular housing B of two different pore sizes, described The internal diameter of annular housing A is less than the internal diameter of annular housing B, the annular housing A respectively with the major diameter of piston 8 and guide sleeve 10 Outer circle cooperation；The both ends of the annular housing B and inner casing 7 cooperate.

Further, such as Fig. 4-5, the annular housing A points be the both ends A1, A2 and annular housing B to divide be the both ends B1, B2 In, annular housing A is matched with the outer circle of 8 maximum diameter of piston；Annular housing B and 7 both ends of inner casing respectively with its be matched with B1 and B2.The design effectively reduces piston return back pressure, improves target efficiency, so that delivery efficiency greatly improves.

Further, tapered face a is machined on the guide sleeve 10, the tapered face a and processing are on 9 inner wall of outer tube The tapered face b of positioning match, and then to guide sleeve 10 position.So that outer tube 9 is processed more convenient, and make size smart Degree is easy to control, and reduces difficulty of processing.

Further, the impactor gas circuit is using no Zigzag type gas circuit structure.Avoid existing impactor air flue turnover And distance is long, the big problem of pressure loss.And above structure is simplified the initial stage heat treatment process of impactor.

Further, the rear joint 1 is fixedly linked by API screw thread its air inlet with drilling rod.

Further, the position matched on the distribution bar 5 with inner casing 7 is equipped with the second O-ring 6.

Further, the position that the outer tube 9 and rear joint 1 match is equipped with the first O-ring 3；The snap ring 12 Using subdivision structure, the outer circle of the snap ring 12 is equipped with third O-ring 11.

The working principle of the utility model is as follows:

To start impactor, impactor must be first transferred.When drill bit 14 and rock contact and jacks up piston and be in shown in Fig. 1 When position, starting preparation comes to an end.

The high pressure gas P0 introduced by the hollow duct J of rear joint, opens non-return valve 2, through distribution bar side channel K, housing Annular chamber C to piston body surface air supply chamber D is formed with inner casing outside on the inside of pipe.High pressure gas by alternately entering gas before cylinder here Room F and rear gas chamber G.

When return starts, piston is in position shown in Fig. 1, and the high pressure gas in annular chamber C is through piston body surface air drain D, warp It crosses piston body table and pushes piston motion into preceding gas chamber F.In the movement of piston return, when circular passage E is closed, preceding gas chamber F Air inlet stops, and the high pressure gas expansion in the forward gas chamber of piston continues up, behind the front end of piston and guide sleeve disengagement, Preceding gas chamber F gas drains into bottom hole such as Fig. 6 through bit central hole I.

Piston start return movement when, the gas P of rear gas chamber G, through piston centre stomata H, bit central stomata I escape to Bottom hole, suffered back pressure resistance very little when making piston motion；When distribution bar microcephaly, which initially enters piston, constitutes cooperation, piston Return movement compress the gas of rear gas chamber G；It is open when piston big end moves to be formed with the interior inside wall of cylinder, high pressure gas Enter rear gas chamber G through annular chamber C, piston body surface air drain D.Due to piston motion inertia, piston slides a distance, until entering The high pressure gas of rear chamber G, which generates pressure, makes piston terminate return movement.

When piston stroke moves, piston moves to piston big end under the promotion of high pressure gas and opens with what the interior inside wall of cylinder was formed Mouth turn-off transient, the channel that high pressure gas enters rear gas chamber are blocked, and piston travels forward by gas expansion, works as piston center hole After being detached from distribution bar lower end, rear gas chamber's gas drains into bottom hole through H, I.Stroke movement is completed in Piston knocking bit tail portion at this time. When piston starts stroke movement, the gas of preceding gas chamber F continues on through guide sleeve and bit central hole I is discharged to bottom hole；Before piston When end enters guide sleeve, the gas of preceding gas chamber starts to compress, and piston, which moves to always, connects arc groove E, and high pressure gas enters Preceding air cavity F, completes distribution process.

Through the above description, those skilled in the art completely can be without departing from this item utility model technical idea In the range of, it carries out various changes and amendments and is within the protection scope of the utility model.The utility model is not use up Matters belong to the common knowledge of those skilled in the art.

Claims (10)

1. having specific length than, the piston of weight ratio and drill bit supporting structure, it is characterised in that: the overall length of the piston (8) The ratio of L2 and the overall length L1 of drill bit (14) are as follows: 1-1.35；The weight ratio of the piston (8) and drill bit (14) are as follows: 1-1.35.

2. according to claim 1 there is specific length to exist than, the piston of weight ratio and drill bit supporting structure, feature In: the ratio of the overall length L1 of the overall length L2 and drill bit (14) of the piston (8) are as follows: 1.15-1.30.

3. according to claim 1 there is specific length to exist than, the piston of weight ratio and drill bit supporting structure, feature In: the weight ratio of the piston (8) and drill bit (14) are as follows: 1.05-1.20.

4. according to claim 1 there is specific length to exist than, the piston of weight ratio and drill bit supporting structure, feature In: the ratio of the overall length L1 of the overall length L2 and drill bit (14) of the piston (8) are as follows: 1.18.

5. according to claim 1 there is specific length to exist than, the piston of weight ratio and drill bit supporting structure, feature In: the weight ratio of the piston (8) and drill bit (14) are as follows: 1.06.

6. using described in claim 1-5 any one with specific length than, the piston of weight ratio and drill bit supporting structure Impactor, it is characterised in that: it includes rear joint (1), is connected with outer tube (9) on the rear joint (1)；The outer tube (9) internal sleeve is equipped with inner casing (7), there is the distribution bar (5) by rear joint (1) location and installation inside the inner casing (7), described The inside cavity of distribution bar (5) is equipped with non-return valve (2), is equipped with spring (4) in the inside cavity of non-return valve (2)；It is described outer It is equipped with piston (8) inside casing (9), one end of the piston (8) is matched with the inner wall of inner casing (7), with piston (8) The guide sleeve (10) that its other end can be internal with outer tube (9) is mounted on is moved to be slidably matched；Pacify the end of the outer tube (9) Equipped with front connector (13), the end face location and installation that the front connector (13) and guide sleeve (10) match has snap ring (12)；It is described The inside of front connector (13) is slidably installed by snap ring (12) limit to be had drill bit (14), the impact end surface of the drill bit (14) It is engaged with the end face of piston (8), and transmits impact energy；

The outer tube (9) is internally provided with the annular housing A and annular housing B of two different pore sizes, the annular housing A's Internal diameter is less than the internal diameter of annular housing B, and the outer circle of the annular housing A and the maximum outside diameter of piston (8) cooperate；The annular chamber The both ends of body B and inner casing (7) cooperate.

7. it is according to claim 6 with specific length than, the impactor of the piston of weight ratio and drill bit supporting structure, Be characterized in that: the outer circle of the inner casing (7) is equipped with orientational cone-shaped surface (e), the conical surface (d) of the orientational cone-shaped surface (e) and outer tube (9) It matches；The middle part of the distribution bar (5) is equipped with support level, and the support level dress is matched with the stepped hole of inner casing (7)； The large end face of the rear joint (1) is compressed the large end face of distribution bar (5) by matching the precession of screw thread with outer tube (9) It is fixed on the end face of inner casing (7), rear joint (1), distribution bar (5), inner casing (7) and outer tube (9) is made to constitute rigid connection；It is described The valve seat and distribution bar (5) of non-return valve (2) use integral structure.

8. it is according to claim 6 with specific length than, the impactor of the piston of weight ratio and drill bit supporting structure, Be characterized in that: the inside of the piston (8) has only drilled through centre bore, and gas channel was machined on the outer wall of piston (8)；Piston (8) arc transition is used between the different diameters of axle.

9. it is according to claim 6 with specific length than, the impactor of the piston of weight ratio and drill bit supporting structure, It is characterized in that: being machined with tapered face (a) on the guide sleeve (10), the tapered face (a) and processing are on outer tube (9) inner wall The tapered face (b) of positioning match, and then to guide sleeve (10) position.

10. it is according to claim 6 with specific length than, the impactor of the piston of weight ratio and drill bit supporting structure, It is characterized by: the position matched on the distribution bar (5) with inner casing (7) is equipped with the second O-ring (6)；

The position that the outer tube (9) and rear joint (1) match is equipped with the first O-ring (3)；The snap ring (12) uses and cuts open The outer circle of separation structure, the snap ring (12) is equipped with third O-ring (11).