CN116085348A

CN116085348A - Middle cylinder body structure of hydraulic breaking hammer

Info

Publication number: CN116085348A
Application number: CN202310194595.8A
Authority: CN
Inventors: 王东凯; 徐贺; 徐莉; 于永伟
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-03-09
Filing date: 2022-03-09
Publication date: 2023-05-09
Also published as: CN114562493A

Abstract

The invention provides a middle cylinder body structure of a hydraulic breaking hammer, and relates to the technical field of hydraulic breaking hammers, wherein the structure comprises a middle cylinder body and pistons, wherein piston fixing parts in clearance fit with the middle cylinder body are arranged on inner peripheral walls of two ends of the middle cylinder body along the axial direction of the middle cylinder body; the auxiliary protection part on the piston fixing part is arranged on the inner side of the main body of the fixing part by adopting polyether-ether-ketone through die casting, the piston can firstly contact and rub with the support ring arranged on the inner side wall of the auxiliary protection part in an eccentric state, and when the radial supporting force of the support ring is compressed or the abrasion is zero, the piston starts to contact with the auxiliary protection part; the auxiliary protection part can provide long-term continuous radial supporting force for the piston, so that abrasion to the piston is avoided. When the breaking hammer is severely biased, the piston is continuously subjected to eccentric force to cause serious eccentricity at a certain point, at the moment, the piston positioning part plays a role, the piston positioning part taking polyether-ether-ketone as a main material can effectively play a role in protecting the middle cylinder, the inner cavity of the middle cylinder is prevented from being scratched, and the service life of the breaking hammer is prolonged.

Description

Middle cylinder body structure of hydraulic breaking hammer

The application is a divisional application of a patent application named as a middle cylinder body structure of a hydraulic breaking hammer, and the application date of the original application is 2022, 03 and 09, and the application number is 202210229283.1.

Technical Field

The invention relates to the technical field of hydraulic breaking hammers, in particular to a middle cylinder body structure of a hydraulic breaking hammer.

Background

The excavator is engineering machinery equipment commonly used in engineering construction, along with the improvement of industrial level and the development of productivity, intelligent automatic control is gradually trended, and the breaking hammer is used as one of the most common accessories in the excavator, and is widely applied to the uses of construction, mountain opening, metallurgy, demolition, road administration and the like.

In order to meet the requirement of impact energy generated by up-and-down reciprocating motion of a piston during operation of the breaking hammer, a gap is sealed between the piston and the cylinder in the breaking hammer, and a single side of 0.07-0.11 mm is designed for the gap between the piston and the cylinder. When the breaking hammer works for a long time, the drill rod can not guarantee the complete vertical state during the operation, and the long-time piston and the drill rod collide to cause the inclined surface to appear on the contact surface, thereby combining the above two points, the cylinder piston in the breaking hammer can swing in the middle cylinder, the long-time swing causes the piston to be not coaxial with the inner cavity of the middle cylinder, the piston contacts and scrapes the middle cylinder, and the cylinder and the piston are scratched and worn, namely: "pull-out" occurs. Whether the cylinder body is scratched or the piston is scratched, the service life of the sealing element is directly influenced, when the cylinder body is scratched slightly, the sealing system is in oil leakage condition, internal leakage causes pressure loss, external leakage not only reduces the pressure dramatically, but also causes a large amount of hydraulic oil loss, and when the cylinder body is scratched seriously, the cylinder body cannot be sealed, so that the whole middle cylinder body is scrapped.

Furthermore, breaking hammers tend to be of high impact design due to industry development needs. There are two conventional methods for improving the striking force of the breaking hammer, one is to increase the diameters of a cylinder body and a piston in the breaking hammer, namely: the model of the breaking hammer is increased. The second is to increase the striking force by increasing the hydraulic pressure. In either design, the problem of the clearance between the piston and the middle cylinder body is not separated, and the problem of the eccentricity of the piston is considered in order to improve the impact energy of the piston, so in the middle and large breaking hammer, the clearance between the piston and the middle cylinder body has to be selected to be larger so as to reduce the collision probability of the piston and the middle cylinder body as much as possible. However, when the gap between the piston and the middle cylinder body is enlarged, the service life of the sealing element is seriously affected, and the situation that the root of the inner lip of the sealing element bites the root is mainly reflected in that the root of the inner lip of the sealing element is extruded into the gap due to overlarge gap between the piston and the middle cylinder body, high hydraulic frequency and high pressure, the sealing element is seriously distorted and deformed and cannot be restored, so that the sealing is invalid, the breaking hammer starts to leak oil, and when serious, the sealing element is cracked, so that the radial supporting force of the sealing element on the piston is reset, the high-frequency collision between the piston and the middle cylinder body occurs, and serious scratch is caused, namely: the "pull" condition occurs.

In summary, the industry is currently plagued by the two problems of "cylinder pulling" and insufficient striking force, and many enterprises and individuals try to improve or solve the two problems through some conventional methods.

The patent with publication number CN206246453U discloses a guide ring for a piston of a hydraulic breaking hammer, which has an inclined opening structure and is convenient to install or replace. In this publication, the entire guide ring can indeed be easily installed or replaced, but the specific use is not ideal. The open guide ring is a common oil cylinder guide mechanism, but is not applicable to the oil cylinder of the breaking hammer, and the piston of the cylinder body in the breaking hammer has extremely high dead weight and extremely high impact kinetic energy of high-speed movement, so that the supporting force of the open design at the open end is obviously reduced, the radial supporting force is uneven, and the piston is laterally deviated. And secondly, the compression modulus of the material is relatively low no matter the guide ring made of tetrafluoroethylene or the copper guide ring is selected, and the material can be irreversibly deformed after supporting the piston for a long time, so that the guide effect is lost.

The patent with publication number CN111350715A discloses a middle cylinder guide structure of a hydraulic breaking hammer, wherein guide sleeve designs are respectively added to the front cavity and the rear cavity of a middle cylinder body, the guide sleeve is in clearance fit with a piston, and when the piston moves at a high speed, the piston and the guide sleeve slide mutually, so that strain caused by contact between the middle cylinder body and the piston is avoided. The design disclosed in the publication can play a certain role in protecting the collision between the piston and the middle cylinder body, but the material of the disclosed guide sleeve is still 40CrNi2Mo in alloy steel, when the piston moves at a high speed, the guide sleeve is contacted with the piston, the position of strain can appear on the inner wall of the guide sleeve and the outer wall of the guide part of the piston, and the guide sleeve and the piston must be replaced at the same time when the piston is scratched to a certain extent, and the middle cylinder body is protected but the whole piston is not protected substantially.

The patent with publication number CN112372240A discloses a processing method of a supporting sleeve and the supporting sleeve, the application principle is the same as that of publication number CN111350715A, the piston in the cylinder body is supported by the guiding sleeve, and the design in the publication number changes the material of the supporting sleeve (or the guiding sleeve) into copper. The copper supporting sleeve (or the guide sleeve) can effectively protect the whole piston and greatly lighten the abrasion to the piston, but the supporting force and the abrasion resistance of the copper supporting sleeve are insufficient, and after the copper supporting sleeve contacts the eccentric piston for a long time, the copper sleeve can deform irrecoverably and is accompanied by a large amount of abrasion copper powder. The radial supporting force to the piston after the copper bush is deformed can be worse and worse, the supporting and guiding functions are finally lost, and the worn copper powder can enter a hydraulic medium to scratch a rubber sealing piece, so that the sealing is invalid, and leakage is caused.

The patent with publication number CN110219851A discloses a piston guiding structure of a hydraulic breaking hammer, and the key point of the design is that a guiding belt mounting groove and a guiding belt are additionally arranged in a mode of feeding and discharging hydraulic oil of a middle cylinder body. The coaxiality of the piston and the inner cavity of the middle cylinder body can be improved to a certain extent by optimizing the inlet and outlet modes of hydraulic oil in the middle cylinder body, but the guiding effect of the piston of the large breaking hammer is insufficient, so the publication number designs a guiding belt as supporting and guiding effects. The key guide belt design does not mention the data such as materials, performances, dimensions, precision and the like, so that the actual application effect of the guide belt cannot be accurately judged.

In addition, the method of increasing the clearance between the piston and the middle cylinder body to avoid 'cylinder pulling' exists in the industry, but as the clearance is too large for the sealing element, the root extrusion of the sealing element is caused, and a retainer ring with smaller inner diameter is added at the bottom of the sealing element to block the root extrusion of the sealing element. In theory, the method can be realized, but in practical application, because the high-pressure and high-frequency hydraulic pressure in the middle cylinder body is very strict on the material and the size design requirement of the check ring, the shape of the check ring can be changed due to the working condition of the high-frequency and high-pressure, the thickness direction is reduced, the diameter direction is expanded, the outer diameter is blocked in the groove and cannot be changed, so that the inner diameter can be gradually reduced, the inner side of the check ring is seriously extruded or directly damaged, the broken check ring scratches the main oil seal, and the main oil seal is damaged, so that the sealing system fails, and the problem of the check ring is difficult to solve in practical application.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a middle cylinder body structure of a hydraulic breaking hammer.

In order to achieve the above object, the present invention provides the following solutions:

a middle cylinder structure of a hydraulic breaking hammer, comprising a middle cylinder and a piston assembled on the middle cylinder, wherein:

the inner peripheral walls of the two ends of the middle cylinder body along the axial direction of the middle cylinder body are provided with piston fixing parts which are in clearance fit with the middle cylinder body; the piston fixing part comprises a fixing part main body and an auxiliary protection part, wherein the fixing part main body is made of alloy steel materials, and the auxiliary protection part is made of polyether-ether-ketone materials and is combined with the inner side of the fixing part main body through die casting; an oil seal mounting groove and a supporting ring mounting groove are formed in the inner side wall of the auxiliary protection part, the piston can firstly contact and rub with a supporting ring in the supporting ring mounting groove in an eccentric state, and the piston contacts with the auxiliary protection part on the inner side of the piston fixing part when the radial supporting force of the supporting ring is compressed or the abrasion is clear;

a piston positioning part is fixedly arranged on the middle section of the outer peripheral wall of the piston, is made of polyether-ether-ketone material, and is combined with the outer periphery of the piston through die casting; the clearance between the piston fixing part and the piston and the clearance between the piston positioning part and the middle cylinder body are all 0.05-0.07 mm;

the polyether-ether-ketone material comprises a modified polyether-ether-ketone material or a pure polyether-ether-ketone material; the supporting ring is made of polyoxymethylene or polytetrafluoroethylene;

the service life of the hydraulic breaking hammer is 600-1000 hours.

Preferably, the auxiliary protection part and the piston positioning part are made of carbon fiber reinforced polyether-ether-ketone materials.

Preferably, a piston hole for accommodating the piston is formed in the middle cylinder body, the piston is installed in the piston hole and can move relative to the piston hole in the axial direction, a plurality of first oil grooves are formed in the wall of the piston hole at intervals along the central axis direction of the piston hole, and the first oil grooves are arranged between the two piston fixing parts; a sealing piece is arranged between the piston fixing part and the middle cylinder body, wherein the sealing piece is a sealing ring or a polyurethane dumbbell; a sealing groove is formed in the peripheral wall of the fixing part main body, and the piston fixing part and the middle cylinder body are sealed through an O-shaped sealing ring arranged in the sealing communication; a plurality of annular oil grooves are formed in the peripheral wall of the piston positioning part at intervals along the central axis direction of the piston positioning part; the piston fixing part of the middle cylinder body, which is close to the drill rod, is a first piston fixer, and the supporting ring mounting groove of the first piston fixer is arranged at the end part far away from the drill rod; the piston fixing part arranged on the middle cylinder body and close to the nitrogen chamber is a second piston fixer, and the supporting ring mounting groove on the second piston fixer is arranged at the end part close to the drill rod.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

according to the middle cylinder body structure of the hydraulic breaking hammer, in the middle cylinder body operation process, the piston is subjected to high-frequency reciprocating motion under hydraulic pressure in the inner cavity of the middle cylinder body, when the piston is in an eccentric state, friction is firstly carried out on the piston and the supporting ring, the piston is the same as a normal breaking hammer, when the hydraulic breaking hammer is operated for a long time, radial supporting force of the supporting ring can be compressed or worn out to clear, and at the moment, the piston is in contact with an auxiliary protection part (made of polyether-ether-ketone material) on the inner side of a piston fixing part. The polyether-ether-ketone material adopted by the auxiliary protection part has extremely strong impact strength, temperature resistance, wear resistance and self-lubricating property, so that long-term continuous radial supporting force can be provided for the piston, the piston can swing in a small range, and meanwhile, the abrasion to the piston is reduced. When the breaking hammer is severely biased, the piston continuously receives the eccentric force, so that the eccentric force is seriously generated at a certain point, at this time, the piston positioning part at the periphery of the piston plays a role, and the piston positioning part taking the polyether-ether-ketone material as a main material can effectively play a role in protecting the inner cavity of the middle cylinder body when the piston positioning part collides, so that the inner cavity of the middle cylinder body is prevented from being scratched, the maintenance cost of the breaking hammer is greatly reduced, and the service life of the breaking hammer is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a hydraulic breaking hammer according to an embodiment of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a schematic diagram illustrating the cooperation between a piston and a piston positioning portion according to an embodiment of the present invention;

fig. 4 is a schematic structural view of a piston fixing portion (a first piston holder or a second piston positioner) provided in an embodiment of the present invention;

fig. 5 is a schematic structural view of a support ring according to an embodiment of the present invention.

Reference numerals illustrate: 1. a middle cylinder; 2. a piston; 3. a piston fixing portion; 31. a first piston holder; 32. a second piston holder; 4. an oil seal mounting groove; 5. a support ring mounting groove; 6. a piston positioning portion; 61. a first positioning table; 62. a second positioning table; 7. a piston bore; 8. sealing the groove; 9. a drill rod; 10. a nitrogen chamber; 11. a support ring; 110. an opening; 12. a fixing part main body; 13. an auxiliary protection part.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

The terms "first," "second," "third," and "fourth" and the like in the description and in the claims of this application and in the drawings, are used for distinguishing between different objects and not for describing a particular sequential order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, inclusion of a list of steps, processes, methods, etc. is not limited to the listed steps but may alternatively include steps not listed or may alternatively include other steps inherent to such processes, methods, products, or apparatus.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

Referring to fig. 1 to 5, the present invention provides a middle cylinder structure of a hydraulic breaking hammer, comprising a middle cylinder 1 and a piston 2 assembled on the middle cylinder 1, wherein, the inner peripheral walls of the two ends of the middle cylinder 1 along the axial direction thereof are provided with piston fixing parts 3, and the piston fixing parts 3 are in clearance fit with the middle cylinder 1; the piston fixing portion 3 shown in fig. 4 includes a fixing portion main body 12 and an auxiliary protecting portion 13, the fixing portion main body 12 is made of alloy steel material, and the auxiliary protecting portion 13 is made of polyetheretherketone material and is combined to the inner side of the fixing portion main body 12 by die casting; an oil seal mounting groove 4 and a supporting ring 11 mounting groove are formed in the inner side wall of the auxiliary protection part 13, the piston 2 can firstly contact and rub with the supporting ring 11 in the supporting ring 11 mounting groove in an eccentric state, and the piston 2 contacts with the auxiliary protection part 13 on the inner side of the piston fixing part 3 when the radial supporting force of the supporting ring 11 is compressed or the abrasion is zero.

In the normal use process, the supporting ring 11 provides a certain supporting force for the piston 2, so that the piston 2 is prevented from contacting the middle cylinder body 1. When the support ring 11 loses the support function during long-time operation, the piston 2 is in contact with the piston fixing part 3, and the auxiliary protecting part 13 on the inner side of the piston fixing part 3 has excellent protecting function on the piston 2, so that the piston 2 is prevented from being scratched.

In practical application, the breaking hammer is in the condition of high-pressure bias for a long time, and the long-term high-pressure bias causes collision with small probability in the inner cavity of the piston 2 or the middle cylinder 1, so that the middle parts of the piston positioning part 6 and the inner cavity of the middle cylinder 1 are damaged by pulling. In the invention, a piston positioning part 6 is fixedly arranged on the middle section of the outer peripheral wall of the piston 2, and the piston positioning part 6 is made of polyether-ether-ketone material and is combined with the outer periphery of the piston 2 through die casting. The piston positioning part 6 taking the polyether-ether-ketone material as the main material can effectively play a role in protecting the inner cavity of the middle cylinder body 1 when collision occurs, and prevent the inner cavity of the middle cylinder body 1 from being scratched.

The auxiliary protection portion 13 may be made of a modified polyetheretherketone material or a pure polyetheretherketone material (abbreviated as PEEK), and is fixed on the inner side of the fixing portion main body 12 by die casting, that is, the piston fixing portion 3 in this embodiment is formed by compounding alloy steel and carbon fiber reinforced polyetheretherketone (or pure polyetheretherketone material); the piston positioning part 6 can also be made of modified polyether-ether-ketone material or pure polyether-ether-ketone material and is fixed on the periphery of the piston 2 through die casting. The auxiliary protecting part 13 and the piston positioning part 6 in the invention are preferably made of carbon fiber reinforced polyether ether ketone (C-PEEK for short).

The middle cylinder 1 is provided with a piston hole 7 for accommodating the piston 2, the piston 2 is installed in the piston hole 7 and can move relative to the piston hole 7 in the axial direction, a plurality of first oil grooves are arranged on the wall of the piston hole 7 (refer to the inner wall of the middle cylinder 1) along the central axis direction of the piston hole 7 at intervals, and the first oil grooves are arranged between the two piston fixing parts 3.

A sealing element is arranged between the piston fixing part 3 and the middle cylinder body 1, wherein the sealing element is a sealing ring or a polyurethane dumbbell. Preferably, a sealing groove 8 is provided on the outer peripheral wall of the fixing portion main body 12, and the piston fixing portion 3 and the middle cylinder 1 are sealed by an O-ring seal installed in the sealing communication for preventing leakage of high pressure oil from the outer diameter of the piston fixing portion 3.

The inner wall of the piston fixing part 3 (i.e. the inner side wall of the auxiliary protection part 13) is provided with an oil seal mounting groove 4 and a support ring 11 mounting groove, the support ring 11 shown in fig. 5 is mounted in the support ring 11 mounting groove, specifically, as shown in fig. 1 and 2, the piston fixing part 3 on the middle cylinder body 1, which is close to the drill rod 9, is a first piston fixer 31, and the support ring 11 mounting groove on the first piston fixer 31 is arranged at the end part far away from the drill rod 9; the piston fixing part 3 arranged on the middle cylinder body 1 near the nitrogen chamber 10 is a second piston 2 fixer, and a supporting ring 11 mounting groove on the second piston 2 fixer is arranged at the end near the drill rod 9. According to the hydraulic breaking hammer illustrated in fig. 1, the second piston holder 32 is located above the first piston holder 31, and a plurality of grooves are formed in the second piston holder 32, wherein one groove at the bottom of the second piston holder 32 is designed as a supporting ring mounting groove 5, the other grooves on the second piston holder 32 are all oil seal mounting grooves 4, and the oil seal grooves on the second fixing part are all located above the supporting ring 11 mounting grooves of the second piston holder 32; similarly, a plurality of grooves are also arranged on the first piston holder 31, wherein one groove at the uppermost part of the first piston holder 31 is designed as a supporting ring mounting groove 5, the other grooves on the first piston holder 31 are designed as oil seal mounting grooves 4, and the oil seal grooves on the first fixing part are all positioned below the supporting ring 11 mounting grooves on the first piston holder 31.

The supporting ring 11 may be a common polyoxymethylene supporting ring 11, or a polytetrafluoroethylene supporting ring 11 modified by fine copper powder, and the supporting ring 11 protrudes inwards from the inner surface of the auxiliary protecting portion 13, and provides radial support through the supporting ring 11. The support ring 11 is provided with an opening 110 for easy disassembly.

The middle part of the outer peripheral wall of the piston 2 is provided with two piston positioning parts 6 which are arranged at intervals, namely a first positioning table 61 and a second positioning table 62, as shown in fig. 3, a plurality of annular oil grooves are arranged on the outer peripheral wall of the first positioning table 61 at intervals along the central axis direction of the first positioning table 61, and a plurality of annular oil grooves are also arranged on the outer peripheral wall of the second positioning table 62 for lubrication. Of these, the first positioning table 61 and the second positioning table 62 are preferably bonded to the outer periphery of the piston 2 by die casting using C-PEEK.

In the process of working of the middle cylinder body 1, the piston 2 is subjected to high-frequency reciprocating motion under hydraulic pressure in the inner cavity of the middle cylinder body 1, when the piston 2 is in an eccentric state, friction is firstly carried out on the piston 2 and the supporting ring 11, the piston is the same as a normal breaking hammer, when the piston works for a long time, radial supporting force of the supporting ring 11 can be compressed or worn out to be cleared, and at the moment, the piston 2 is in contact with an auxiliary protection part 13 (C-PEEK) on the inner side of the piston fixing part 3. Because the C-PEEK adopted by the auxiliary protection part 13 has extremely strong impact strength, temperature resistance, wear resistance and self-lubricating property, long-term continuous radial supporting force can be provided for the piston 2, and the abrasion or scratch to the piston 2 is reduced while the piston 2 is ensured to swing in a small range.

When the breaking hammer is severely biased, the piston 2 is continuously subjected to the eccentric force, so that the eccentric force is seriously generated at a certain point, at the moment, the piston positioning part 6 at the periphery of the piston 2 plays a role in timely correcting the piston 2, and the piston positioning part 6 taking the C-PEEK as a main material can effectively play a role in protecting the inner cavity of the middle cylinder body 1 when the breaking hammer collides, so that the inner cavity of the middle cylinder body 1 is prevented from being scratched, and the service life of the breaking hammer is prolonged.

The sealing system must not seal after the piston 2 is scratched, and the scratched piston 2 also scratches the sealing element, which speeds up the failure of the seal. And the piston 2 is difficult to repair after being scratched, and only the whole piston 2 can be replaced, the reasons are as follows:

(1) When designing the middle cylinder body 1 of the breaking hammer, the gap between the piston 2 and the middle cylinder body 1 is an important parameter, and the gap is designed in a matching way with other parts; the repairing piston 2 can only be polished by a grinder, the diameter of the polished piston 2 is reduced, the gap between the piston 2 and the middle cylinder body 1 is increased, and a plurality of matched parts and parameters are changed, so that a plurality of abnormal problems of the crushing hammer are caused;

(2) After the gap between the piston 2 and the middle cylinder body 1 is increased, the oil seal is designed according to the standard grooves and the gap, so that the oil seal with proper size is difficult to match, after the gap is increased, the probability that the root part of the inner lip of the oil seal is extruded into the gap is very high, and the whole breaking hammer is not provided with a stable sealing system, so that the breaking hammer cannot be used.

Because of the physical properties (excellent supporting property and wear resistance) of the C-PEEK, the central cylinder body 1 and the piston 2 have better protection effects, and a powerful guarantee is provided for the gap between the piston positioning part 6 and the inner wall of the central cylinder body 1 or the gap between the piston 2 and the piston fixing part 3 when the central cylinder body 1 is designed. Through the action of the C-PEEK, the clearance of the piston 2 can be designed to be 0.05-0.07 mm on one side, which means that the clearance between the piston fixing part 3 and the piston 2 and the clearance between the piston positioning part 6 and the middle cylinder body 1 can be designed to be 0.05-0.07 mm. Compared with the design of 0.07-0.11 mm in the current industry, the gap design can obviously improve the striking force of the breaking hammer, simultaneously provides a powerful supporting effect for the sealing element, avoids the extrusion phenomenon of the root part of the inner lip of the sealing element, and prolongs the service life of a sealing system, thereby prolonging the service life of the breaking hammer.

The invention solves the technical problem that the service life of the breaking hammer is influenced by the cylinder pulling phenomenon caused by scratch easily generated in the moving process of the existing piston 2 and the middle cylinder body 1, and also generates immeasurable economic benefit. The normal oil seal replacement time of the breaking hammer is 400-500 hours, the oil seal must be replaced when reaching 500 hours, otherwise, the situation of cylinder pulling is very easy to occur. In practical application, in order to avoid the situation of pulling the cylinder, the user generally needs to replace the oil seal within 350-400 hours. The breaking hammer with the diameter of 200mm for one piston 2 has the cost of replacing the oil seal about 4000 yuan, the income of one day of operation about 12000 yuan, the total cost of comprehensive calculation and maintenance (oil seal replacement and misoperation cost) about 16000 yuan, and the average cost per hour is 16000 yuan/400 hours = 40 yuan according to the oil seal replacement calculation of 400 hours of operation.

The hydraulic breaking hammer with the middle cylinder body structure can effectively avoid the situation of cylinder pulling, the breaking hammer can be used for 600-1000 hours (1000 hours is the life limit of the oil seal due to the life problem of the oil seal), maintenance and oil seal replacement calculation is carried out according to 600 hours, and the average cost per hour is 16000 yuan/600 hours = 26.6 yuan. In summary, the user can save at least 33% of the cost.

In addition, in the prior art, when the middle cylinder body 1 and the piston 2 of the breaking hammer are in a 'cylinder pulling' condition, the breaking hammer is usually processed through a boring cylinder, but the middle cylinder body 1 is huge in size and high in price, and the concentricity and the true roundness are required to be extremely high, so that the cost of the boring cylinder is extremely high, and the middle cylinder body 1 of the boring cylinder is required to be newly customized for a piston 2 with an enlarged diameter to be used in a matched mode, so that the cost of the breaking hammer boring cylinder with the piston diameter of 200mm is hundreds of thousands of yuan. Moreover, the oil seal after the boring cylinder is required to be a customized nonstandard oil seal, the standard oil seal cannot be normally used, the maintenance cost after the boring cylinder is greatly increased, and the performance and stability of the breaking hammer after the boring cylinder cannot be compared with those of breaking hammers produced by original factories. The invention fundamentally relieves the problem of 'pulling the cylinder', avoids the situation that the inner cavity of the middle cylinder body 1 of the breaking hammer collides with the piston 2 to produce strain as much as possible, and the C-PEEK material on the piston fixing part 3 and the piston positioning part 6 in the middle cylinder body 1 can be repaired or combined again in a high heat treatment mode, so that the boring cylinder of the middle cylinder body 1 is avoided, the piston 2 does not need to be replaced, the design values of the repaired or combined middle cylinder body 1 and piston 2 are the same as those of the original factory, the overall performance and stability of the breaking hammer are not affected, the later maintenance cost is greatly reduced, the old hammer is ensured to have the same performance as the new hammer, and the immeasurable economic benefit is produced.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.

The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.

Claims

1. The utility model provides a well cylinder structure of hydraulic breaking hammer which characterized in that includes well cylinder body and the piston of assembly on well cylinder body, wherein:

the service life of the hydraulic breaking hammer is 600-1000 hours.

2. The middle cylinder structure of the hydraulic breaking hammer according to claim 1, wherein the auxiliary protecting part and the piston positioning part are made of carbon fiber reinforced polyether-ether-ketone materials.

3. The middle cylinder structure of the hydraulic breaking hammer according to claim 1, wherein a piston hole for accommodating the piston is arranged in the middle cylinder, the piston is installed in the piston hole and can move relative to the piston hole in the axial direction, a plurality of first oil grooves are arranged on the wall of the piston hole at intervals along the central axis direction of the piston hole, and the first oil grooves are arranged between the two piston fixing parts; a sealing piece is arranged between the piston fixing part and the middle cylinder body, wherein the sealing piece is a sealing ring or a polyurethane dumbbell; a sealing groove is formed in the peripheral wall of the fixing part main body, and the piston fixing part and the middle cylinder body are sealed through an O-shaped sealing ring arranged in the sealing communication; a plurality of annular oil grooves are formed in the peripheral wall of the piston positioning part at intervals along the central axis direction of the piston positioning part; the piston fixing part of the middle cylinder body, which is close to the drill rod, is a first piston fixer, and the supporting ring mounting groove of the first piston fixer is arranged at the end part far away from the drill rod; the piston fixing part arranged on the middle cylinder body and close to the nitrogen chamber is a second piston fixer, and the supporting ring mounting groove on the second piston fixer is arranged at the end part close to the drill rod.