阅读说明：本技术 锥套式无扩口导管的收压方法 (Taper sleeve type flaring-free guide pipe compression method ) 是由 安小慧 王华国 曾卫国 蒋晟 刘晓朴 单建秋 唐佳纯 于 2020-12-17 设计创作，主要内容包括：锥套式无扩口导管的收压方法,包括：对锥套式无扩口导管收压组合过程进行PFMEA分析；对锥形套进行收压中的受力进行分析；确定收压操作中的收压压力值；使用润滑油对锥形套的锥面进行润滑,根据确定的收压压力值对锥套式无扩口导管进行收压操作。本发明的锥套式无扩口导管的收压方法,通过控制制造误差及零件表面等不确定影响因素,改进工作方法、确定各档尺寸导管的收压压力值,大大提升了锥套式无扩口导管的收压成功率。使用本发明的锥套式无扩口导管的收压方法进行收压,6mm外径导管的收压合格率可达到85％以上,其他各档尺寸导管的收压合格率达到97％以上,收压合格率远高于现有的收压方法。(The method for compressing the taper sleeve type flaring-free guide pipe comprises the following steps: PFMEA analysis is carried out on the taper sleeve type flaring-free guide pipe compression combination process; analyzing the stress of the conical sleeve in the compression process; determining a pressure reduction pressure value in pressure reduction operation; lubricating the conical surface of the conical sleeve by using lubricating oil, and performing pressure reducing operation on the conical sleeve type flaring-free guide pipe according to the determined pressure reducing value. According to the method for compressing the taper sleeve type non-flaring guide pipe, the working method is improved and the compression pressure value of the guide pipe with each grade of size is determined by controlling uncertain influence factors such as manufacturing errors and the surface of a part, so that the compression forming power of the taper sleeve type non-flaring guide pipe is greatly improved. When the taper sleeve type flaring-free guide pipe compression method is used for compression, the compression qualified rate of the guide pipe with the outer diameter of 6mm can reach more than 85%, the compression qualified rate of the guide pipes with other sizes can reach more than 97%, and the compression qualified rate is far higher than that of the existing compression method.)

1. The method for compressing the taper sleeve type flaring-free guide pipe is characterized by comprising the following steps of:

s1: PFMEA analysis is carried out on the taper sleeve type flaring-free guide pipe compression combination process;

s2: analyzing the stress of the conical sleeve in the compression process;

s3: determining a pressure reduction pressure value in pressure reduction operation;

s4: and lubricating the conical surface of the conical sleeve by using lubricating oil, and performing pressure reducing operation on the conical sleeve type non-flaring catheter according to the pressure reducing pressure value determined in the step S3.

2. The pressure reducing method according to claim 1, wherein the step S3 specifically includes: and determining the pressure value in the pressure reducing operation according to the pipe material and the outer diameter of the taper sleeve type non-flaring conduit.

3. The calendering method of claim 2, wherein the pipe is an aluminum pipe or a steel pipe.

4. The compacting method as claimed in claim 3, wherein the aluminum pipe has an outer diameter of 6 to 20mm and a corresponding compacting pressure value of 1.2 to 1.72 MPa.

5. The method according to claim 3, wherein the outer diameter of the steel pipe is 6-16 mm, and the corresponding pressure reduction value is 1.4-3.5 MPa.

6. The pressure reducing method according to any one of claims 1 to 5, wherein the step S4 specifically includes: checking the parts before the pressure relief operation to eliminate the problem parts, preassembling, matching and checking the pressure relief dies, setting the hydraulic pressure relief equipment according to the pressure relief pressure value determined in the step S3, assembling the guide pipe and the conical sleeve, lubricating the conical surface of the conical sleeve by using lubricating oil, placing and positioning, and performing pressure relief forming.

7. The method of claim 6, wherein the lubricating oil is YH-15 hydraulic oil.

Technical Field

The invention relates to a compression process, in particular to a compression method of a taper sleeve type flaring-free guide pipe.

Background

For a taper sleeve type flareless conduit (7A4-78 type), the taper sleeve type flareless conduit is mainly applied to the field of aviation and the like, and the existing method mainly comprises the steps of manufacturing a compression mould, and enabling the taper sleeve to be compressed on the appearance of the conduit under the action of hydraulic pressure (a hand-operated pump is used in the early stage, and the proportional pressure control is generally used at present) to manufacture a conduit assembly meeting the requirements. Although the existing pressure recovery method has the defects that the pressure recovery pressure is favorably and accurately controlled by improving the working pressure precision of the pressure recovery hydraulic cylinder, the process parameters are unstable due to the existence of uncertain factors such as manufacturing errors and part surfaces, and the process continuity between the guide pipes with different sizes is not strong, so that the success rate of products is low, and the product is frequently reworked, for example, the pressure recovery qualification rate of the guide pipe with the outer diameter of 6mm is only 20-30%.

Disclosure of Invention

The invention aims to provide a method for compressing a taper sleeve type flaring-free guide pipe, which researches the actual action effect of compression pressure by a PFMEA (pulse frequency membrane electrode assembly) method and by using stress analysis, thereby improving the working method, determining the compression pressure value of the guide pipe with each grade of size and improving the compression success rate of a product by controlling uncertain influence factors such as manufacturing errors, part surfaces and the like.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

the method for compressing the taper sleeve type flaring-free guide pipe comprises the following steps:

s1: PFMEA analysis is carried out on the taper sleeve type flaring-free guide pipe compression combination process;

s2: analyzing the stress of the conical sleeve in the compression process;

s3: determining a pressure reduction pressure value in pressure reduction operation;

s4: and lubricating the conical surface of the conical sleeve by using lubricating oil, and performing pressure reducing operation on the conical sleeve type non-flaring catheter according to the pressure reducing pressure value determined in the step S3.

As a preferred technical solution, the step S3 specifically includes: and determining the pressure value in the pressure reducing operation according to the pipe material and the outer diameter of the taper sleeve type non-flaring conduit.

As a preferred technical scheme, the pipe is an aluminum pipe or a steel pipe.

According to the preferable technical scheme, the outer diameter of the aluminum pipe is 6-20 mm, and the corresponding pressure reduction pressure value is 1.2-1.72 MPa.

According to the preferable technical scheme, the outer diameter of the steel pipe is 6-16 mm, and the corresponding pressure reduction pressure value is 1.4-3.5 MPa.

As a preferred technical solution, the step S4 specifically includes: checking the parts before the pressure relief operation to eliminate the problem parts, preassembling, matching and checking the pressure relief dies, setting the hydraulic pressure relief equipment according to the pressure relief pressure value determined in the step S3, assembling the guide pipe and the conical sleeve, lubricating the conical surface of the conical sleeve by using lubricating oil, placing and positioning, and performing pressure relief forming.

Preferably, the lubricating oil is YH-15 hydraulic oil.

Compared with the prior art, the invention has the beneficial effects that:

according to the method for compressing the taper sleeve type flaring-free guide pipe, the actual action effect of the compression pressure is researched by utilizing the stress analysis through the PFMEA method, so that the working method is improved, the compression pressure value of the guide pipe with each grade of size is determined by controlling uncertain influence factors such as manufacturing errors and the surface of a part, and the compression forming power of the taper sleeve type flaring-free guide pipe is improved; in the pressure reducing process of the pressure reducing method of the taper sleeve type flaring-free guide pipe, the working pressure of the pressure reducing hydraulic cylinder is reasonably reduced compared with the conventional typical value and has better consistency; when the taper sleeve type flaring-free guide pipe compression method is used for compression, the compression qualified rate of the guide pipe with the outer diameter of 6mm can reach more than 85%, the compression qualified rate of the guide pipes with other sizes can reach more than 97%, and the compression qualified rate is far higher than that of the existing compression method.

Drawings

FIG. 1 is a schematic view of the taper angle configuration of a taper sleeve type flareless conduit and a taper sleeve in an embodiment of the present invention;

FIG. 2 is an exploded view of the angle values at the two ends of the tapered sleeve in an embodiment of the present invention;

FIG. 3 is a pressure reducing process in an embodiment of the present invention

In fig. 1, 1 guide tube, 2 outer sleeve nut and 3 conical sleeve.

The specific implementation mode is as follows:

the technical solution of the present invention is clearly and completely described below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

1. PFMEA analysis of taper sleeve type flaring-free guide pipe compression combination process

The following analysis was performed based on the requirements of sealability and flexibility indexes after pressure reduction. The basic process steps are as follows: the method comprises the steps of part inspection before operation, preassembly, match and inspection of a compression mould, operation of hydraulic compression equipment, placement and positioning, compression forming, appearance inspection and test sample testing. Since the taper sleeve type flareless catheter and the used equipment are all available, the detailed operation method is well known to those skilled in the art, and thus the detailed description is omitted. The primary Failure Mode (FM) is a failure of the taper sleeve to the depth of collapse of the catheter surface. The main Factors (FC) and preventive measures (PC) are: the alignment mode of the placement and positioning is unreasonable, and the mode is adjusted as follows: the guide pipe with the pre-installed conical sleeve is firstly jacked on a feeding die, and the outer sleeve nut is guided into a fixing die along with the feeding action, so that the positioning is completed. Secondly, the wedge effect of the primary compression pressing against the dental cusp is analyzed, and the secondary compression is prohibited because the secondary compression is changed into surface contact. Thirdly, when the equipment is pressurized, the working pressure is unreasonable, the pressurization process is analyzed, and measures of coating YH-15 hydraulic oil for lubrication are taken according to the analysis result.

2. Analyzing stress in compression of conical sleeve

The taper angles of the taper sleeve type flareless conduit and the taper sleeve are shown in figure 1. The objective of the analysis of the force mechanism is: firstly, measuring and calculating the relation between the equipment pressure receiving effect and the conical sleeve pressure receiving effect, and optimizing the equipment pressure receiving pressure; secondly, defining the action factors with poor effect.

And (3) analysis results: (1) force is subjected to force triangular decomposition from the angle values of the two ends of the conical sleeve (figure 2), wherein N is_P-retracting the hydraulic loading force of the hydraulic cylinder; n is a radical of_F-a positive pressure transmitted by the 50 ° cone onto the outer wall of the catheter; n is a radical of_F' -positive pressure transmitted by the 65 deg. cone end to the outer wall of the catheter; n-the positive pressure (total pressure) transmitted on the cone.

If the axial hydraulic loading force is Np, the force is transmitted from the outer sleeve nut/the pressure-receiving mold core to the axis direction along the conical surface of the conical sleeve, and therefore the following effects are achieved: a. a cone angle of 50 degrees is arranged at one end of the outer sleeve nut, and the tooth shape of the outer sleeve nut is transferred to the positive pressure N on the outer wall of the catheter_F2.15 Np; b. at one end of the mould core is 65 degrees, and the tooth shape of the mould core is transferred to the positive pressure N on the outer wall of the conduit_F'＝1.57N_P. It can be seen that the conical sleeve is constructed such that its pressure on the outer wall of the conduit is a booster effect and that the two positive pressures N_F、N_FThe availability of efficient delivery is a major factor in determining the pressure recovery.

(2) During debugging, the outer sleeve nut and the conical sleeve are often tightly clamped during compression. From the stress triangle, the positive pressure acting on the conical surface respectively reaches 2.37 times and 1.86 times, and the force acts to form friction force; meanwhile, the actual roughness of the joint surface of the conical sleeve and the outer sleeve nut is Ra1.6 and Ra3.2 respectively, the conical sleeve and the outer sleeve nut are rough, and under the boosting effect of about twice, the generated friction force is very large, part of hydraulic loading force can be offset, and the key point of the pressure-receiving effect is to reduce the friction, so that the problem can be solved by adopting a lubricating method, and the pressure-receiving effect is stabilized.

Based on the above analysis, the following data (tables 1 and 2) were determined for the crush process parameters for both steel and aluminum types of catheters after lubricating the conical surface with YH-15 hydraulic oil. Through improvement, the working pressure of the pressure-receiving hydraulic cylinder is reasonably reduced, and better continuity is presented.

TABLE 1 COMPARATIVE TABLE OF PRESSURE OF CONE SLEEVE OF ALUMINIUM CATHETER

The current typical value is the determined pressure value (MPa) of the invention, and the original typical value is the current pressure value (MPa)

TABLE 2 Cone sleeve pressure comparison table for steel conduit

The current typical value is the determined pressure value (MPa) of the invention, and the original typical value is the current pressure value (MPa)

For the convenience of production operation, the invention combines the precision of a pressure gauge of an equipment meter, the reading error is selected to be about 0.2MPa, and the pressure receiving pressure value in the operation is determined as follows according to the current typical value:

TABLE 3 aluminum conduit crimping pressure and tolerance

TABLE 4 pressure and tolerance of steel guide tube

And (3) performing pressure reduction operation on various taper sleeve type non-flaring conduits according to the process flow chart in the figure 3 and the pressure values determined in the tables 3 and 4, wherein the pressure reduction qualified rate of the conduit with the outer diameter of 6mm reaches more than 85% through inspection and test, and the pressure reduction qualified rate of the conduits with the sizes of other gears reaches more than 97%. Therefore, the compression method improves the working method and determines the compression pressure value of the guide pipe with each grade of size by controlling uncertain influence factors such as manufacturing errors, part surfaces and the like, and greatly improves the compression forming power of the taper sleeve type non-flaring guide pipe.