CN103182626A - Machining detection process for part - Google Patents

Abstract

The invention relates to a machining detection process for a part. The process comprises the following steps of: 1, blanking; 2, determining a dimension chain of the part; 3, roughly turning the material blanked by the step 1 according to the dimension chain of the part, which is determined in the step 2; 4, performing thermal treatment on the roughly-turned material; 5, accurately grinding the dimension chain of the part, which is determined in the step 2; and 6, electroplating a product obtained in the step 5. According to the machining detection process for the part, the qualified rate of the product is high, the machining accuracy is high, and process steps are rational.

Description

The processing characterization processes of parts

Technical field

The invention belongs to machining detection technique field, relate to a kind of processing characterization processes of parts.

Background technology

The large aircraft industry is the strategic industry that highlights a national comprehensive strength, independent development large aircraft is a long-cherished wish of Chinese aeronautical chart, can promote the development of a national basis science and basic industries by the large aircraft industry, drive large quantities of related industries.China's Aviation Industry has possessed technology and the material base of making large aircraft through 60 years of development, and the large aircraft amount of parts is numerous, and each parts all will be through the effect of affected by hot loading and surrounding medium.Installing rack is the semi-finished product parts of large aircraft, in manufacturing process, the taper pin type component is ornamental in order to strengthen it, increase its wearability, anti-corrosive properties, often need to adopt electric plating method to improve its processing chemical property, but in detail of design, often this type component only marks its final size and final thickness of coating, so in the parts production process, operation according to reality, needing the middle process size to calculate, all is given process dimension by virtue of experience at present, and process is electroplated in control again, final product only carries out outward appearance and electroplates the detection of back size, does not carry out thickness of coating and detects.Along with the raising of product assembling link performance, strengthen product is detected, find that many product plating thickness do not meet the detail of design requirement.

Therefore, in parts machining, testing process, when people's adopting process dimension chain is found the solution process dimension, analysis, mistake in computation easily, how correctly to analyze, calculate process, formulate rational processing step, guarantee that the machining accuracy of electroplated product coating is necessary.

Summary of the invention

In order to solve the above-mentioned technical problem that exists in the background technology, the invention provides the processing characterization processes of a kind of product percent of pass height, machining accuracy height and the rational parts of processing step.

Technical solution of the present invention is: the invention provides a kind of processing characterization processes of parts, its special character is: the processing that comprises following parts detects step:

1) blanking;

2) determine the dimension chain of parts;

3) according to step 2) in the dimension chain of determined parts carry out rough turn to the material of step 1);

4) material after rough turn is heat-treated;

5) according to step 2) in the dimension chain of determined parts finish grind;

6) product that obtains through step 5) is electroplated.

Above-mentioned dimension chain is in the assembling process of parts processing, measurement or machine, the size that some that run into connect each other; These sizes are to be connected into closing form according to a definite sequence, and such packet size is exactly dimension chain.The principal character of dimension chain: each size is interconnected to closing form; The change value of a certain size is accepted the influence of other dimensional variations in the dimension chain.

Each size in the above-mentioned dimension chain abbreviates ring as, according to each effect of ring in dimension chain, can be divided into closed-loop and makeup ring: closed-loop is a last ring that forms in assembling or process; Makeup ring is to the influential whole rings of closed-loop in the dimension chain.Makeup ring is pressed its difference that influences to closed-loop, can be divided into again increasing ring or subtracting ring.Increase ring: under the constant condition of other makeup rings, when this ring increased, closed-loop increased thereupon; Subtract ring: under the constant condition of other makeup rings, when this ring increased, closed-loop reduced thereupon.

Above-mentioned closed-loop is to be determined by the lower deviation of the upper deviation of the basic size of closed-loop, closed-loop and closed-loop;

The basic size N of closed-loop equals all and increases ring Ai basic size and deduct all and subtract ring Bj, that is:

$N=\stackrel{n}{\mathrm{\Σ}}\mathrm{Ai}-\stackrel{n}{\mathrm{\Σ}}\mathrm{Bj};$

The upper deviation ESN of closed-loop equals all and increases ring upper deviation ESAi sum and deduct all and subtract ring lower deviation EIBj sum, that is:

$\mathrm{ESN}=\stackrel{n}{\mathrm{\Σ}}\mathrm{ESAi}-\stackrel{n}{\mathrm{\Σ}}\mathrm{EIBj};$

The lower deviation EIN of closed-loop equals all and increases ring lower deviation EIAi sum and deduct all and subtract ring upper deviation ESBj sum, that is:

$\mathrm{EIN}=\stackrel{n}{\mathrm{\Σ}}\mathrm{EIAi}-\stackrel{n}{\mathrm{\Σ}}\mathrm{ESBj};$

Wherein: i=1,2,3,4,5～N; J=1,2,3,4,5～N.

The processing characterization processes of above-mentioned parts also comprises after step 6):

7) according to step 2) in the dimension chain of determined parts the resulting parts of step 6) are carried out secondary correct grinding.

Advantage of the present invention is:

The present invention correctly analyzes, calculates process dimension chain, determine process dimension, tolerance and specification requirement, help to improve the reasonability of electrodeposited coating precision technological design, because the complexity that connects each other between the process dimension, so determine that process dimension, surplus and dimensional problem must be from the angles of whole technical process, the method synthesis of adopting process dimension chain calculates.The present invention increases precision grinding process by the calculating of process dimension chain before electroplating and after electroplating, to reach the purpose that improves electrodeposited coating control accuracy and crudy.The present invention has not only reduced the disqualification rate of electroplated product, and has improved the machining accuracy of electroplated product, has guaranteed the interchangeability of final electroplated product assembling link, its craft science, feasibility height.

Description of drawings

Fig. 1 is the first embodiment schematic diagram that adopts method provided by the present invention that certain parts is processed;

Fig. 2 is the second embodiment schematic diagram that adopts method provided by the present invention that certain parts is processed.

The specific embodiment

Traditional parts processing technology is: blanking, and---car---heat treatment---is electroplated, such processing technology is owing to have certain blindness, the disqualification rate of the parts that it is processed to form is higher, processing experience through inventor's long-term accumulation, traditional parts processing technology is made radical reforms, calculating by dimension chain, determine the process of production process, calculate parts thickness of coating parameter, and art production process is controlled in strictness in process of production, guarantee the quality of final products, adopt the qualification rate height of the parts of new processing technology formation, precision also significantly promotes.

Processing technology after reform may further comprise the steps:

------carrying out rough turn according to dimension chain,---heat treatment---is finish grinded---plating---and is carried out the secondary correct grinding according to dimension chain according to dimension chain to determine the dimension chain of parts in blanking.

Wherein, for the dimension chain of parts:

One, dimension chain and key property thereof

In the assembling process of parts processing, measurement or machine, what often run into is not some isolated sizes, but some sizes that connect each other.These sizes are connected into closing form according to a definite sequence, and such packet size is exactly dimension chain.The key property of dimension chain: each size is interconnected to constitute closing form; The change value of a certain size is accepted the influence of other dimensional variations in the dimension chain.

Two, the composition of dimension chain

Each size in the dimension chain is called for short ring, according to each effect of ring in dimension chain, can be divided into closed-loop and makeup ring.

(1) closed-loop: a last ring that forms is called closed-loop in assembling or process.

(2) makeup ring: in the dimension chain to the influential whole rings of closed-loop.

Makeup ring is pressed its difference that influences to closed-loop, can be divided into again increasing ring or subtracting ring.

Increase ring: under the constant condition of other makeup rings, when this ring increased, closed-loop increased thereupon.

Subtract ring: under the constant condition of other makeup rings, when this ring increased, closed-loop reduced thereupon.

Three, the computational methods of closed-loop:

The basic size of closed-loop (N) equals all and increases ring (Ai) basic size and deduct all and subtract ring (Bj) basic size.That is: $N=\stackrel{n}{\mathrm{\Σ}}\mathrm{Ai}-\stackrel{n}{\mathrm{\Σ}}\mathrm{Bj}$

The upper deviation of closed-loop (ESN) equals all and increases the ring upper deviation (ESAi) sum and deduct all and subtract ring lower deviation (EIBj) sum.That is:

The lower deviation of closed-loop (EIN) equals all and increases ring lower deviation (EIAi) sum and deduct all and subtract the ring upper deviation (ESBj) sum.That is:

Four, the method (seeing Table 1) of tabulation driven dimension chain:

The computational methods of table 1 dimension chain

Five, the determination methods of dimension chain:

Referring to Fig. 1, be office's cutaway view of gear-box, as seen from the figure, N is the size that is obtained by last assembly relation, can't directly measure, so N is the closed-loop in this dimension chain.Utilization is rotated counterclockwise method or the method that turns clockwise, the size A consistent with the N direction ₃, A ₄, A ₅For subtracting ring; The size A opposite with the N direction ₁, A ₂For increasing ring.

Installing rack taper pin type component such as Fig. 2 (a) material 30CrMnSiA,

Be detail of design final size (i.e. plating back size), electroplated decorative chromium (Fe/EpCu15ApNi10bCr0.3cf) is adopted in surface treatment, and the analysis by process dimension chain such as Fig. 2 (b) obtains: thickness of coating (N), final size (A ₀), size (A before the plating ₁) form a dimension chain, according to the definition of closed-loop, thickness of coating (N) is to measure to be of a size of closed-loop final size (A indirectly ₀) for increasing ring, size (A before the plating ₁) for subtracting ring.

Use original machining process route, process before the taper pin plating of numerical control turning processing

Technological coating thickness

Plate the back size by calculating of process dimension chain

Obviously should plating afterwards size do not meet the detail of design final size, illustrate that numerical control turning can't process the taper pin that satisfies the pattern required precision, namely there is drawback in original processes route.

By analyzing, the crux of finding the problems referred to above is that the tolerance value of thickness of coating is too little, so adopt new machining process route, this new technology need at first calculate correct grinding size before the plating, has only the final size tolerance dwindled or to increase the thickness of coating dimensional tolerance for this reason.Be 0.009mm by consulting standard of tolerance numerical tabular IT6 level tolerance, IT10 level tolerance is 0.058mm, obviously adopts fine grinding technology, and the product precision can reach the requirement of IT6 class precision.The processing method of correct grinding is adopted in preliminary technological design, the size after processing is electroplated

Technological coating thickness

Calculate the preceding size of plating according to top design

Arrive this, find that again numerical control grinding can't process the taper pin that satisfies the pattern required precision, new process is imperfection also? demonstration is reanalysed in deep thinking again, electrodeposited coating thickness deviation (correct grinding final size less than normal during the taper pin of the grinding tolerance IT6 level that has its source in of pinpointing the problems Tolerance be the IT6 level, can not reduce again), at this moment, redefine technological coating thickness, increase thickness of coating Recomputate (seeing Table 2), correct grinding size before can plating

A ₁Tolerance be 0.009mm, meet IT6 level tolerance, be the most effective tolerance of grinding.

Correct grinding size calculation before table 2 plating

Ring	Basic size	The upper deviation	Lower deviation
				Increase ring	∮6.3	-0.055	-0.064
Subtract ring	-∮6.3	+0.098	+0.089
				Closed-loop	0	+0.043	+0.025

Take all factors into consideration grinding and electroplating processing process, finally the processing route of definite taper pin type component is: blanking, and--rough turn----correct grinding--plating---correct grinding is worked out this process route, and emphasis finish grindes size before will controlling and electroplating in heat treatment

The electrodeposited coating gauge

Electroplate the back final size

Adopt new-type like this machining process route can guarantee that product is absolutely qualified.

Claims (6)

1. the processing characterization processes of parts, it is characterized in that: the processing characterization processes of described parts may further comprise the steps:

1) blanking;

2) determine the dimension chain of parts;

3) according to step 2) in the dimension chain of determined parts carry out rough turn to the material of step 1);

4) material after rough turn is heat-treated;

5) according to step 2) in the dimension chain of determined parts finish grind;

6) product that obtains through step 5) is electroplated.

2. the processing characterization processes of parts according to claim 1, it is characterized in that: described dimension chain is some sizes that connect each other that run in the assembling process of parts processing, measurement or machine; The described size that these connect each other is to be connected into closing form according to a definite sequence.

3. the processing characterization processes of parts according to claim 2, it is characterized in that: each size in the described dimension chain abbreviates ring as, and described dimension chain comprises closed-loop and makeup ring; Described closed-loop is a last ring that forms in assembling or process; Described makeup ring is to the influential whole rings of closed-loop in the dimension chain.

4. the processing characterization processes of parts according to claim 3 is characterized in that: described makeup ring comprises and increases ring and subtract ring; When the constant condition of other makeup rings, the described ring that increases increases, and closed-loop increases thereupon; When the constant condition of other makeup rings, the described ring that subtracts increases, and closed-loop reduces thereupon.

5. the processing characterization processes of parts according to claim 4 is characterized in that: described closed-loop is to be determined by the lower deviation of the upper deviation of the basic size of closed-loop, closed-loop and closed-loop;

The basic size N of described closed-loop equals all and increases ring Ai basic size and deduct all and subtract ring Bj, that is:

$N=\stackrel{n}{\mathrm{\Σ}}\mathrm{Ai}-\stackrel{n}{\mathrm{\Σ}}\mathrm{Bj};$

The upper deviation ESN of described closed-loop equals all and increases ring upper deviation ESAi sum and deduct all and subtract ring lower deviation EIBj sum, that is:

$\mathrm{ESN}=\stackrel{n}{\mathrm{\Σ}}\mathrm{ESAi}-\stackrel{n}{\mathrm{\Σ}}\mathrm{EIBj};$

The lower deviation EIN of described closed-loop equals all and increases ring lower deviation EIAi sum and deduct all and subtract ring upper deviation ESBj sum, that is:

$\mathrm{EIN}=\stackrel{n}{\mathrm{\Σ}}\mathrm{EIAi}-\stackrel{n}{\mathrm{\Σ}}\mathrm{ESB};$

Wherein: i=1,2,3,4,5～N; J=1,2,3,4,5～N.

6. according to the processing characterization processes of claim 1 or 2 or 3 or 4 or 5 described parts, it is characterized in that: the processing characterization processes of described parts also comprises after step 6):

7) according to step 2) in the dimension chain of determined parts the resulting parts of step 6) are carried out secondary correct grinding.

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