英文讲解

Aircraft Rivet（飞机铆钉）

Several methods are used to hold metal parts together; they include riveting（铆接）, bolting（螺栓连接）, brazing（钎焊）, and welding（焊接）. To make a good union and a strong joint, aluminum parts can be welded, bolted, or riveted together. Riveting is much easier to do than welding. It is the most common method used to fasten or join aluminum alloys in aircraft construction and repair.

What is a Rivet? A rivet is a metal pin with a formed head on one end.

How is a Rivet used? The shank（杆） of the rivet is inserted into a drilled hole, and its shank is then upset (deformed) （变形）by a hand or pneumatic tool（气动工具）. The second head, formed either by hand or by pneumatic equipment, is called a “shophead”（墩头）.

Before a rivet is driven（铆打）, it should extend beyond the base material at least one and a half times the rivet diameter（铆钉直径）. Once driven, the rivet shank expands to fill the hole and the bucktail（墩头） expands to one and a half times its original diameter. Once the bucktail expands to the appropriate diameter it should extend beyond the base material by at least one half the original rivet diameter.

Two of the major types of rivets used in the aircraft are (1) the common solid-shank（实芯）type, which must be driven using a bucking bar（垫块）, (2) and the special (blind盲型) rivets, which may be installed where it is impossible to use a bucking bar.

Solid shank rivets have been used since sheet metal was first utilized in aircraft and remains the single most commonly used aircraft fastener today.

Solid shank rivets are generally used in repair work. They are identified by the kind of material of which they are made, their head type（头型）, size of shank, and their temper condition.

Specifications and Standards（规范和标准）

All materials and hardware used on aircraft must be designed and built to a standard. Each individual aircraft produced from a given design must meet the same standards. All materials and hardware must be manufactured to a standard of quality（质量）.

Rivet Part Code（铆钉件号）

A part number (part code) identifies（识别） each type of rivet so that the user can select the correct rivet for the job. The type of rivet head is identified by AN or MS standard numbers. The numbers selected are in series and each series represents a particular type of head.

AN426 or MS20426—countersunk head rivets (100°)（100度埋头铆钉）

AN430 or MS20430—roundhead rivets（圆头铆钉）

AN441—flathead rivets（平头铆钉）

AN456—brazier head rivets（扁头铆钉）

AN470 or MS20470—universal head rivets（通用头铆钉）

There are also letters and numbers added to a part number. The letters designate（指定） alloy content; the numbers designate rivet diameter and length.

Rivet Head Type（铆钉头型）

Solid shank rivets are available in several head shapes, but the universal and the 100° countersunk head are the most commonly used in aircraft structures.

The AN470 (MS20470) Universal Head（通用头） rivet was designed for use in areas where Airflow was not an issue with the installation of the rivet.

The AN426 (MS20426) CounterSunk （埋头）Rivet was designed for use in areas where we want a minimum of disruption（分离）of the airflow.

The universal head rivet(AN470,MS20470) is a combination of the roundhead, flathead, and brazier head. It is used in aircraft construction and repair in both interior and exterior locations. When replacement is necessary for protruding head rivets（凸头铆钉）— roundhead（圆头）, flathead（平头）, or brazier head（扁头）—they can be replaced by universal head（通用头） rivets.

Length of Rivet（铆钉长度）

The length of a universal head (AN470) rivet is measured from the bottom of the manufactured head to the end of the shank.

The length of a countersunk rivet (AN426) is measured from the top of the manufactured head to the end of the shank.

Identification（铆钉识别）

Most aircraft rivets are made of an aluminum alloy. The type of alloy is identified by a letter in the rivet code, and by a mark（标记）on the rivet head.

The markings on the heads of rivets indicate the material of which they are made.

Solid Shank Rivets（实芯铆钉）

• 1100 Rivet（纯铝铆钉）

The 1100 rivet, which is composed of 99.45 percent pure aluminum, is very soft. It is for riveting the softer aluminum alloys, such as 1100, 3003, and 5052, which are used for nonstructural parts. The riveting of map cases is a good example of where a rivet of 1100 aluminum alloy may be used.

• 2117-T Rivet（外场铆钉）

The 2117-T rivet, known as the field rivet（外场铆钉）, is used more than any other for riveting aluminum alloy structures. The field rivet is in wide demand, because it is ready for use as received and needs no further heat treating or annealing. It also has a high resistance to corrosion.

• 2017-T and 2024-T Rivets（冰箱铆钉）

The 2017-T and 2024-T rivets are used in aluminum-alloy structures where more strength is needed than is obtainable with the same size 2217-T rivet. These rivets are known as “ice box rivets（冰箱铆钉）,” are annealed and must be kept refrigerated until they are to be driven. The 2017-T rivet should be driven within approximately 1 hour and the 2024-T rivet within 10 to 20 minutes after removal from refrigeration.

• 5056 Rivet（铝镁合金铆钉）

The 5056 rivet is used for riveting magnesium（镁）-alloy structures because of its corrosion-resistant（抗腐蚀）qualities in combination with magnesium.

• 7050T73 Rivet（铝锌合金铆钉）

A new and stronger rivet alloy was developed in 1979 called 7050T73.The letter E is used to designate this alloy, and the rivet head is marked with a raised circle. 7050 alloy contains zinc as the major alloying ingredient and is precipitation heat-treated. This alloy is used by the Boeing Airplane Company as a replacement for 2024T31 rivets in the manufacture of the 767 widebody aircraft. （2024-硬铝；7050-超硬铝）

Ice-Box Rivets（冰箱铆钉）

The rivet must be soft, or comparatively soft, before a good head can be formed. The 2017-T and 2024-T rivets are annealed before being driven. They harden with age（随效硬化）, they begin to age-harden（时效硬化） within a few minutes after being exposed to room temperature.

They must be used immediately after quenching（淬火）or else be placed in cold storage. The 2017-T rivet should be driven within approximately 1 hour and The 2024-T rivet within 10 to 20 minutes after removal from refrigeration（冷冻）.

The most commonly used means for holding heat treatable rivets at low temperature (below 32°F) is to keep them in an electric refrigerator. They will remain soft enough for driving for periods up to 2 weeks. Any rivets not used within that time should be removed for re-heat treating.

Icebox rivets attain about one-half their maximum strength in approximately 1 hour after driving and full strength inabout 4 days. When 2017-T rivets are exposed to room temperature for 1 hour or longer, they must be subject to reheat treatment. This also applies to 2024-T rivets exposed to room temperature for a period exceeding 10 minutes.

Once an icebox rivet has been taken from the refrigerator, it should not be mixed with the rivets still in cold storage. If more rivets are removed from the icebox than can be used in 15 minutes, they should be placed in a separate container and stored for re-heat treatment. Heat treatment rivets may be repeated a number of times if done properly.

Heat Treatment of Rivets（铆钉的热处理）

Annealing is the process of heating a metal to a prescribed（规定） temperature, holding it there for a specified length of time, and then cooling the metal back to room temperature.

Annealing（退火）is a process that softens（软化） a metal and decreases internal stress（内应力）. In general, annealing is the opposite of hardening.

The heat treatment of alloy 2017 rivets consists of subjecting the rivets to a temperature between 930 °F to 950 °F for approximately 30 minutes and immediately quenching（淬火） in cold water. These rivets reach maximum strength in about 9 days after being driven.

Alloy 2024 rivets should be heated to a temperature of 910 °F to 930 °F and immediately quenched in cold water. These rivets develop greater shear strength than 2017 rivets and are used in locations where extra strength is required. Alloy 2024 rivets develop their maximum shear strength in 1 day after being driven.

The 2017 rivet should be driven within approximately 1 hour and the 2024 rivet within 10 to 20 minutes after heat treating or removal from refrigeration. If not used within these times, the rivets should be reheat treated before being refrigerated.

Quenching（淬火）

The rapid cooling of metal in the heat treatment process. Parts produced from sheet, extrusions, tubing, small forgings, and similar type material are generally quenched in a cold-water bath. The temperature of the water before quenching should not exceed 85 °F. Using a sufficient quantity of water keeps the temperature rise under 20 °F.

Questions?（单项选择题）

1-Calculate the exact length of a 1/8" rivet used to join a sheet of .032" & a sheet of .040".

A. 0.3750" ；B. 0.2595" ；C. 0.3125"； D. 0.4375"

2-Countersunk rivets have a countersink angle of how many degrees?

A. 100；B. 110；C. 85；D. 76

3-Heat treated rivets in the D and DD series that are not driven within the prescribed time after heat treatment or removal from refrigenration

A. must be discarded

B. must be used within 2 weeks

C. must be reheat treated before use

D. may be returned to refrigeration and used later

4-How much rivet shank, measured in terms of rivet diameter, should stick through the metal in order to form a proper shop head?

A. One-half diameter

B. One diameter

C. One and one-half diameters

D. Three diameters

5-Of what material is an aircraft rivet made if it has a raised ring on its head?

A. 7075 alloy；B. 5056 alloy；C. 2024 alloy；D. 2017 alloy

6-Of what material is an aircraft rivet made if it has two raised bars on its head?

A. 2117 alloy；B. 2017 alloy；C. 2024 alloy；D. 5056 alloy

7-Rivet diameters are measured in which increment?

A. 1/16"；B. 1/32"；C. 1/8"；D. 5/32"

8-Rivet lengths are measured in which increment?

A. 1/16"；B. 3/32"；C. 1/8"；D. 5/32"

9-The amount of rivet shank that must protrude from the hole to form a proper shop head is:

A. 2D；B. 3D；C. 1.5D；D. 2.5D

10-The length of a MS20426 rivet is measured from

A. the top of its head to the end of the shank

B. the bottom of its head to the end of the shank

C. the top of its head to the bottom of the manufactured head

D. the top of its head to the bottom of the shop head

11-The length of a rivet to be used to join a sheet of 0.032-inch and 0.064-inch aluminum alloy should be equal to

A. two times the rivet diameter plus 0.064

B. one and one half times the rivet diameter plus 0.096

C. three times the rivet diameter plus 0.064

D. one and one half times the rivet diameter plus 0.064

12-The rivet part number is MS20470A4-4. The alloy used for this rivet is:

A. 2117；B. 1100；C. 2024；D. 2017

13-The rivet part number is MS20470A4-4. The head markings for this rivet would be:

A. a dimple；B. a single raised dash；

C. 2 raised dashes；D. no marks on the head

14-The rivet part number is MS20470DD4-4. The alloy used for this rivet is:

A. 2117；B. 1100；C. 2024；D. 2017

15-The rivet part number is MS20470DD4-4. The head markings for this rivet would be:

A. a dimple；B. a single raised dash；C. 2 raised dashes；D. a raised cross

16-The rivet part number is MS20470DD4-4. The length of this rivet is:

A. 1/8"；B. 3/32"；C. 5/32"；D. 1/4"

17-The solid rivet for installation is 1/8" in diameter with a universal head, the rivet alloy is 2117 & the attaching material is .040" thick. The correct part number for the rivet is:

A. MS20426DD4-4；B. MS20470DD4-4；

C. MS20470AD4-4；D. MS20426AD4-4

18-Under certain conditions, type A rivets are not used because of their

A. high strength characteristics；

B. low strength characteristics

C. high alloy content；

D. tendency toward embrittlement when subjected to vibration

19-What alloy is identified by a raised teat in the center of a rivet head?

A. 2017 alloy；B. 2024 alloy；C. 5056 alloy；D. 7075 alloy

20-What aluminum alloy is used for most of our high strength applications?

A. 1100；B. 2117；C. 3003；D. 7075

21-What is the diameter in terms of rivet shank diameter of a properly formed shop head on a rivet?

A. one-half diameter；B. One diameter；

C. One and one-half diameters；D. Two diameters

22-What is the head shape of an AN426 rivet?

A. flat head；B. round head；

C. Universal head；D. 100-degree countersunk head

23-What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?

A. To accelerate age hardening；B. To retard age hardening

C. To harden the rivets；D. To increase internal stresses

24-What two types of strength must we consider when we design a riveted joint in an aircraft structure?

A. The shear strength of the sheet metal

B. The bearing strength of the rivet

C. The shear strength of the sheet metal and the bearing strength of the rivet

D. The shear strength of the rivet and the bearing strength of the sheet metal

25-What type of rivet is approved for replacing any protruding head rivet?

A. A countersunk rivet；B. A round head rivet

C. A flat head rivet；D. A universal-head rivet

26-When measuring the length of an MS20470AD3-4 rivet before installation, we measure from:

A. The top of the head to the end of the shank

B. The underside of the head to the end of the shank

C. The amount of rivet that is contained in the material before the rivet is driven.

D. None of the above.

27-Which of the following rivets is not a protruding head rivet?

A. AN470；B. AN455；C. AN430；D. AN426

28-Which rivet is used for riveting magnesium alloy structures?

A. Mild steel；B. 5056 aluminum；C. Monel；D. Copper

练习题答案：