CN111036828A - Sealed electromagnetic pulse riveting die for forming raised head rivet - Google Patents

Abstract

The utility model provides a sealed electromagnetic pulse riveting die for plush copper rivet shaping, includes head die and fixes the tail mould on the base, the punching press terminal surface of head die and the top shape cooperation of rivet, the punching press terminal surface diameter of tail mould is greater than the stalk portion diameter of rivet, the punching press terminal surface center of tail mould still is equipped with the cavity, the diameter of cavity is less than the diameter of rivet stalk portion. The sealing electromagnetic riveting head die and the tail die series of the sealing rivets comprising the raised heads of different specifications are formed by the die, the sealing riveting quality is 100% in accordance with the universal riveting technical conditions, the connection performance after forming is superior to that after common sealing electromagnetic riveting dies are riveted, and the consistency of the riveting heads is superior to that of manual sealing riveting.

Description

Sealed electromagnetic pulse riveting die for forming raised head rivet

Technical Field

The invention belongs to riveting process equipment, and particularly relates to a sealing electromagnetic riveting method for a raised head rivet with a diameter of phi 4-phi 6 mm. The application aims at the difficult problems that the sealing riveting defects are frequent and the riveting quality is difficult to guarantee in the using process of the universal electromagnetic riveting die, and the special riveting die is designed according to the sealing electromagnetic riveting construction conditions and the sealing rivet characteristics of the raised head rivet, so that the applicability of the sealing electromagnetic riveting technology is improved.

Background

As a novel process, the electromagnetic riveting has high loading rate and has remarkable advantages on high-strength and large-diameter rivet riveting, composite material riveting, interference fit riveting and the like involved in the production process of aerospace products. Similar to common pneumatic hammering riveting, the electromagnetic riveting needs to be formed by the impact force of an impact end and a jacking end to form an effective rivet heading. In practical application, the method is often in a form similar to a positive riveting method.

Compared with the common riveting, the loading rate of the sealed electromagnetic riveting is very high, the riveting force is very large, the rivet is formed at one time under instantaneous pressure, and stress concentration is very easy to generate when the tail of the rivet is riveted by a common standard riveting die, so that pier head cracks appear; on the nail head side, material crush, nail head indentation, non-bonding of the nail head and the interlayer, etc. are easy to occur. The defects seriously affect the riveting quality and prevent the popularization and application of the sealing electromagnetic riveting technology in the aerospace field. Therefore, the special riveting die design is developed aiming at the construction conditions and the riveting objects of the sealed electromagnetic riveting, and the feasibility of the special riveting die is verified through the process test and the engineering application test, so that the riveting quality of the sealed electromagnetic riveting is improved, the engineering application problem is solved, the engineering application of the sealed electromagnetic riveting in the aerospace field is promoted, and the gap with foreign countries is greatly reduced.

Disclosure of Invention

Electromagnetic riveting has incomparable advantages compared with traditional pneumatic riveting in the application of forming novel skin materials and large-diameter high-strength rivets. The invention discloses a sealed electromagnetic pulse riveting die for forming a raised head rivet, which is used for developing a special riveting die design aiming at the construction conditions and riveting objects of sealed electromagnetic riveting, verifying the feasibility of the special riveting die design through a process test and an engineering application test, improving the riveting quality of sealed electromagnetic riveting and solving the engineering application problem.

The utility model provides a sealed electromagnetic pulse riveting die for plush copper rivet shaping, includes head die and fixes the tail mould on the base, the punching press terminal surface of head die and the top shape cooperation of rivet, the punching press terminal surface diameter of tail mould is greater than the stalk portion diameter of rivet, the punching press terminal surface center of tail mould still is equipped with the cavity, the diameter of cavity is less than the diameter of rivet stalk portion.

Preferably, the head die is designed according to the shape of a semi-circular head rivet head, and the stressed part of the head die is tightly attached to the rivet head.

Preferably, the non-stressed part of the head die is a part where the edge of the head die is not in contact with the nail head, the non-stressed part is designed to be a cavity conical surface, a gap β is formed between the non-stressed part and the nail head, and the gap β is an included angle formed between the non-stressed part and the nail head.

Preferably, the front end face of the head die and the end face of the semicircular head rivet head form a distance delta, and the size of the distance delta is the minimum value which does not cause pressure damage to a riveting piece in riveting.

Preferably, the tail die is designed into a shallow cup shape, and the diameter of the bottom of the tail die is smaller than that of the opening.

Preferably, the diameter of the cavity of the tail die, the depth of the cavity, the inclination angle of the cavity and the fillet at the bottom of the cavity are determined according to the characteristics of rivets with different specifications.

The invention also discloses a use method of the riveting die, which comprises the following steps:

1) selecting a head die and a tail die according to the specification and the diameter of the rivet;

2) the riveting die is in threaded connection with a riveting rod of a riveting gun through the threads of the riveting die to form an effective riveting gun;

3) positioning a workpiece and installing a rivet;

4) the working surface of the head die is matched with the rivet head of the rivet, so that the rivet head is attached to the surface of the interlayer;

5) the concave pit of the working surface of the tail die is matched with the rivet rod, the tail part of the ejector rod is pressed, and the angle of the ejector rod is adjusted, so that the working surface of the ejector rod is tightly attached to the tail part of the rivet;

6) and (4) buckling a riveter to rivet, and forming a pier head at one side of the nail rod.

The invention has the beneficial effects that:

the invention discloses a sealed electromagnetic pulse riveting die for forming raised head rivets, which forms a sealed electromagnetic riveting head die and tail die series comprising raised head sealed rivets with different specifications, wherein the sealed riveting quality is 100 percent and accords with universal riveting technical conditions, the formed connection performance is superior to that of a common sealed electromagnetic riveting die after riveting, and the consistency of the riveted heads is superior to that of manual sealed riveting.

Drawings

FIG. 1 is a schematic view of the design of the rivet head of the riveting die of the present invention;

FIG. 2 is a schematic view of a riveting die head die design of the present invention;

FIG. 3 is a schematic view of the design of the tail die of the riveting die of the present invention.

Detailed Description

A pair of riveting dies consists of two riveting dies, namely a nail head side riveting die (a head die 1 for short) and a nail tail side riveting die (a tail die 2 for short). During the use, select for use the matched with according to sealed riveting condition and rivet specification and rivet the module, form the riveter through the cooperation of the screw thread on the mould screw rod of riveting and the riveting pole on the electromagnetism riveting equipment.

1) Head die

In order to form a nail head meeting the general riveting standard after sealed riveting, a head die 1 is designed according to the shape of the nail head of a half-round head rivet, the stressed part of the head die is tightly attached to the rivet head, the non-stressed part is designed into a die cavity conical surface, a gap β is formed between the non-stressed part and the nail head, the nail head is prevented from being damaged by pressing, and a gap delta is formed between the front end surface of the riveting die and the surface of a material, so that the damage of an interlayer material is prevented, which is shown.

2) Tail die

When a common 180-degree pier head (flat pier head) riveting die is used for sealing electromagnetic riveting, rivet materials are rapidly filled in rivet holes under instantaneous pressure, residual materials flow between the working surface of the riveting die and the surface of an interlayer material, a nail rod cannot be effectively upset, the diameter of the formed pier head is too large, and stress concentration and pier head cracks are easily generated. The tail mould 2 of this patent application designs into shallow cup, through the die cavity to the restriction of nail pole material, the effective control rivet material flow direction. According to the characteristics of rivets with different specifications, the diameter of a cavity of a riveting die, the depth of the cavity, the inclination angle of the cavity and the fillet at the bottom of the cavity are determined, and the special riveting die for the electromagnetic riveting convex tail is formed.

3. Sealed electromagnetic riveting concave riveting die pair series

According to the common raised head rivet series, the electromagnetic riveting concave riveting die pair series of the raised head rivet is formed by changing the working surface parameters of the head die 1 and the tail die 2. When in use, the sealing riveting working conditions and the rivet characteristics are selected in pairs.

The method for sealing the electromagnetic riveting concave riveting die set by using the raised head rivet comprises the following steps:

1. the head die and the tail die are selected from the tables 1, 2 and 3 according to the specifications and the diameters of the rivets, and the parameters of the head die and the tail die refer to the labels of the attached figures 2 and 3 in the specification.

TABLE 1 series for die selection

TABLE 2 Tail die selection series

TABLE 3 series for sealing electromagnetic riveting die pairs of raised-head rivets

2. The riveting die is in threaded connection with a riveting rod of a riveting gun through the threads of the riveting die to form an effective riveting gun;

3. positioning a workpiece and installing a rivet;

4. the working surface of the head die is matched with the rivet head of the rivet, so that the rivet head is attached to the surface of the interlayer;

5. the concave pit of the working surface of the tail die is matched with the rivet rod, the tail part of the ejector rod is pressed, and the angle of the ejector rod is adjusted, so that the working surface of the ejector rod is tightly attached to the tail part of the rivet;

6. and (4) buckling a riveter to rivet, and forming a pier head at one side of the nail rod.

The effects that can reach:

1. forming a sealing electromagnetic riveting head die and a sealing electromagnetic riveting tail die series comprising raised head sealing rivets with different specifications;

2. the sealing riveting quality is 100 percent and meets the universal riveting technical condition;

3. the connection performance after forming is superior to that after the common sealing electromagnetic riveting die is riveted and formed;

4. the riveting consistency of the head is better than that of manual sealing riveting.

Claims (7)

1. The sealing electromagnetic pulse riveting die for forming the raised head rivet is characterized by comprising a head die (1) and a tail die (2) fixed on a base, wherein the punching end face of the head die (1) is matched with the top of the rivet in shape, the diameter of the punching end face of the tail die (2) is larger than the diameter of a handle of the rivet, a concave cavity is further arranged in the center of the punching end face of the tail die (2), and the diameter of the concave cavity is smaller than the diameter of the handle of the rivet.

2. Mould according to claim 1, characterized in that the head mould (1) is designed according to the shape of a half-round head rivet head, and the stressed part of the head mould closely fits the rivet head.

3. The mold according to claim 2, characterized in that the non-stressed portion of the head mold (1) is the portion where the edge of the head mold (1) and the pin head are not in contact, the non-stressed portion is designed as a cavity taper, and the pin head forms a gap β, the gap β is the included angle formed by the non-stressed portion and the pin head.

4. Mould according to claim 2, characterized in that the front face of the head mould (1) and the end face of the half-head rivet head form a distance δ having a size of minimum value that does not cause crushing damage to the rivet when riveting.

5. Mould according to claim 1, characterized in that the tail mould (2) is designed in a shallow cup shape, the bottom diameter being smaller than the diameter of the opening.

6. Mould according to claim 5, characterized in that the diameter of the cavity, the depth of the cavity, the inclination of the cavity and the fillet at the bottom of the cavity of the tail mould (2) are determined according to the characteristics of rivets with different specifications.

7. The method of using a riveting die of claim 1, comprising the steps of:

1) selecting a head die and a tail die according to the specification and the diameter of the rivet;

2) the riveting die is in threaded connection with a riveting rod of a riveting gun through the threads of the riveting die to form an effective riveting gun;

3) positioning a workpiece and installing a rivet;

4) the working surface of the head die is matched with the rivet head of the rivet, so that the rivet head is attached to the surface of the interlayer;

5) the concave pit of the working surface of the tail die is matched with the rivet rod, the tail part of the ejector rod is pressed, and the angle of the ejector rod is adjusted, so that the working surface of the ejector rod is tightly attached to the tail part of the rivet;

6) and (4) buckling a riveter to rivet, and forming a pier head at one side of the nail rod.

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