CN114406174B

CN114406174B - Self-punching riveting method and self-punching riveting device

Info

Publication number: CN114406174B
Application number: CN202210077358.9A
Authority: CN
Inventors: 赵伦; 张亮; 罗义; 陈伟; 龚涛; 甘增康; 林森; 霍小乐
Original assignee: Shenzhen Polytechnic
Current assignee: Shenzhen Polytechnic
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2022-11-29
Anticipated expiration: 2042-01-24
Also published as: CN114406174A

Abstract

The invention relates to the technical field of self-piercing riveting, in particular to a self-piercing riveting method and a self-piercing riveting device. The method comprises the following steps: placing at least two plates to be self-riveted between a blank holder and a die; a punch and a rivet are arranged inside the blank holder, the blank holder is connected with a first ultrasonic transducer, and the die is provided with a groove matched with the rivet; pressing the riveting positions of at least two plates to be self-punched and riveted by using a blank holder and a die; enabling ultrasonic waves emitted by the first ultrasonic transducer to act on the surface of the plate to be subjected to self-piercing riveting, which is in contact with the blank holder, through the blank holder; the ultrasonic wave emitted by the first ultrasonic transducer is vertical to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder; and driving the rivet to extrude the riveting part of at least two plates to be self-piercing riveted by the punch until the groove is completely filled by the plates to be self-piercing riveted and the rivet. This scheme can effectively reduce the probability of rivet fracture deformation.

Description

Self-punching riveting method and self-punching riveting device

Technical Field

The embodiment of the invention relates to the technical field of self-piercing riveting, in particular to a self-piercing riveting method and a self-piercing riveting device.

Background

Self-piercing riveting is a cold joining technique for joining two or more metal sheets. After the special rivet penetrates through the top layer of the plate, the hollow structure at the tail part of the rivet is expanded and penetrated without penetrating through the bottom layer of the plate under the action of the riveting die, so that a firm riveting point is formed. The self-piercing riveting is improved by 30% compared with the common welding spot; the plate can be connected with a plurality of plates which are made of different materials and are difficult to rivet, and can also be connected with a plurality of layers of plates at one time; the coating plate or the plating layer plate can be riveted on the premise of not damaging the plating layer; the riveting process has short period, and can be as short as 1 second.

Currently, an ultrasonic-assisted self-piercing riveting device is provided, and for example, a patent with publication number CN104439684a discloses an ultrasonic-assisted self-piercing riveting method, but ultrasonic waves in the patent act on a rivet, so that the rivet is easily broken and fails to rivet.

Therefore, there is a need for a self-piercing riveting method and a self-piercing riveting device to solve the above technical problems.

Disclosure of Invention

The embodiment of the invention provides a self-piercing riveting method and a self-piercing riveting device, which can effectively reduce the probability of fracture and deformation of a rivet.

In a first aspect, an embodiment of the present invention provides a self-piercing riveting method, including:

placing at least two plates to be self-riveted between a blank holder and a die; the punching head and the rivet are arranged inside the blank holder, the blank holder is connected with a first ultrasonic transducer, and the die is provided with a groove matched with the rivet;

compressing the riveting positions of at least two plates to be self-punched and riveted by using the blank holder and the die;

enabling ultrasonic waves emitted by the first ultrasonic transducer to act on the surface of the plate to be subjected to self-piercing riveting, which is in contact with the blank holder, through the blank holder; the ultrasonic waves emitted by the first ultrasonic transducer are perpendicular to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder;

and driving the punch to extrude riveting positions of at least two plates to be self-piercing riveted until the groove is completely filled with the plates to be self-piercing riveted and the rivet.

In one possible design, a second ultrasonic transducer is connected to the mold;

after the pressing the riveting part of at least two plates to be self-piercing riveted by using the blank holder and the die and before the pressing the punch to the riveting part of at least two plates to be self-piercing riveted, the method further comprises the following steps:

applying ultrasonic waves emitted by the second ultrasonic transducer to the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through the die; the ultrasonic waves emitted by the second ultrasonic transducer are parallel to the surfaces of the at least two plates to be self-piercing riveted, which are in contact with each other.

In one possible design, the ultrasonic waves emitted by the first ultrasonic transducer act on the surface of the sheet material to be self-clinched, which is in contact with the edge holder, for a time of not more than 5s.

In a possible design, after the pressing the punch to the riveting position of at least two sheets to be self-piercing riveted until the groove is completely filled with the sheets to be self-piercing riveted, the method further includes:

and continuing to apply the ultrasonic wave emitted by the first ultrasonic transducer to the surface of the plate to be self-clinched, which is in contact with the blank holder, through the blank holder.

In a second aspect, an embodiment of the invention provides a self-piercing riveting device, which comprises a blank holder, a punch, a rivet, a die and a first ultrasonic transducer, wherein the blank holder is connected with the first ultrasonic transducer, the punch and the rivet are arranged inside the blank holder, and the die is provided with a groove matched with the rivet;

at least two plates to be self-piercing riveted are arranged between the blank holder and the die, the blank holder and the die are used for pressing the riveting parts of the at least two plates to be self-piercing riveted, and the punch is used for driving the rivet to extrude the riveting parts of the at least two plates to be self-piercing riveted;

the ultrasonic waves emitted by the first ultrasonic transducer act on the surface of the plate to be self-piercing riveted, which is in contact with the blank holder, through the blank holder, and the ultrasonic waves emitted by the first ultrasonic transducer are perpendicular to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder.

In a third aspect, an embodiment of the present invention further provides a self-piercing riveting method, including:

placing at least two plates to be self-riveted between a blank holder and a mould; the die is connected with a second ultrasonic transducer, and the die is provided with a groove matched with the rivet;

applying ultrasonic waves emitted by the second ultrasonic transducer to the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through the die; the ultrasonic waves emitted by the second ultrasonic transducer are parallel to the surfaces of the at least two plates to be self-piercing riveted, which are in contact with each other;

and driving the punch to extrude the riveting parts of at least two plates to be self-piercing riveted until the grooves are completely filled by the plates to be self-piercing riveted and the rivets.

In one possible design, the blank holder is connected with a first ultrasonic transducer;

enabling ultrasonic waves emitted by the first ultrasonic transducer to act on the surface of the plate to be subjected to self-piercing riveting, which is in contact with the blank holder, through the blank holder; the ultrasonic waves emitted by the first ultrasonic transducer are perpendicular to the surface of the plate to be self-clinched, which is in contact with the blank holder.

In one possible embodiment, the ultrasonic waves emitted by the second ultrasonic transducer are applied to the surface of at least two sheets to be self-clinched, which surface is in contact with each other, for a period of time not exceeding 5 seconds.

and continuing to apply the ultrasonic waves emitted by the second ultrasonic transducer to the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through the die.

In a fourth aspect, the embodiment of the invention further provides a self-piercing riveting device, which comprises a blank holder, a punch, a rivet, a die and a second ultrasonic transducer, wherein the punch and the rivet are arranged inside the blank holder, the die is connected with the second ultrasonic transducer, and the die is provided with a groove matched with the rivet;

at least two plates to be subjected to self-piercing riveting are arranged between the blank holder and the die, the blank holder and the die are used for pressing the riveting parts of the at least two plates to be subjected to self-piercing riveting, and the punch is used for driving the rivet to extrude the riveting parts of the at least two plates to be subjected to self-piercing riveting;

and the ultrasonic waves emitted by the second ultrasonic transducer act on the surfaces of the at least two plates to be self-piercing riveted, which are in mutual contact, through the blank holder, and the ultrasonic waves emitted by the second ultrasonic transducer are perpendicular to the surfaces of the at least two plates to be self-piercing riveted, which are in mutual contact.

In the embodiments provided by the first aspect and the second aspect, the ultrasonic waves emitted by the first ultrasonic transducer connected with the blank holder are applied to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder, so that the riveting part of the plate to be self-piercing riveted, which is in contact with the blank holder, can be softened, the ultrasonic waves do not need to be directly applied to the rivet, and the probability of fracture and deformation of the rivet can be effectively reduced.

In the embodiments provided by the third and fourth aspects, the ultrasonic waves emitted by the second ultrasonic transducer connected with the die are applied to the surfaces of at least two plates to be self-piercing riveted, which are in contact with each other, so that the riveting part of the plates to be self-piercing riveted can be softened, the ultrasonic waves do not need to be directly applied to the rivet, and the probability of fracture and deformation of the rivet can be effectively reduced; and welding of different plates to be self-piercing riveted can be realized, which is beneficial to improving the connection strength of the plates to be self-piercing riveted and the corrosion resistance of the plates to be self-piercing riveted.

Drawings

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic flow chart of a self-piercing riveting method according to an embodiment of the present invention;

fig. 2 is a schematic flow chart of another self-piercing riveting method according to an embodiment of the present invention;

fig. 3 is a schematic flow chart of another self-piercing riveting method according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a self-piercing riveting device according to an embodiment of the present invention.

Description of the drawings:

10-a frame body;

1-blank holder;

2-a mould;

3-a first ultrasonic transducer;

4-second ultrasonic transducer.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention, and based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the scope of the present invention.

Example one

As shown in fig. 1, an embodiment of the present invention provides a self-piercing riveting method, which includes the following steps:

step 100, placing at least two plates to be self-piercing riveted between a blank holder and a mold; the punching head and the rivet are arranged inside the blank holder, the blank holder is connected with a first ultrasonic transducer, and the die is provided with a groove matched with the rivet;

102, compressing riveting parts of at least two plates to be self-stamped and riveted by using a blank holder and a mould;

104, enabling ultrasonic waves emitted by the first ultrasonic transducer to act on the surface of the plate to be subjected to self-piercing riveting, which is in contact with the blank holder, through the blank holder; the ultrasonic wave emitted by the first ultrasonic transducer is vertical to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder;

and 106, driving the rivet to extrude the riveting part of at least two plates to be self-piercing riveted by the punch until the groove is completely filled with the plates to be self-piercing riveted.

In this embodiment, the ultrasonic waves emitted by the first ultrasonic transducer connected with the blank holder act on the surface of the plate to be self-piercing riveted, which is in contact with the blank holder, so that the riveting part of the plate to be self-piercing riveted, which is in contact with the blank holder, can be softened, and the ultrasonic waves do not need to directly act on the rivet, so that the probability of fracture and deformation of the rivet can be effectively reduced.

It should be noted that, in order to ensure the quality of self-piercing riveting, the riveting thickness (i.e. the sum of the thicknesses of at least two sheets to be self-piercing riveted) needs to be limited within 12 mm.

The first ultrasonic transducer mainly plays a role in ultrasonic-assisted metal forming because the ultrasonic waves emitted by the first ultrasonic transducer are perpendicular to the surface of the plate to be self-clinched, which is in contact with the blank holder. Of course, those skilled in the art will appreciate that the ultrasonic transducer is part of an ultrasonic vibration system, wherein the ultrasonic vibration system includes an ultrasonic generator, an ultrasonic transducer, and a horn. Specifically, the ultrasonic generator converts a power frequency current with a certain frequency into a resonant current with a certain frequency, the resonant current is transmitted to the ultrasonic transducer through an inverse piezoelectric effect, the ultrasonic transducer converts the resonant current into high-frequency vibration, the amplitude transformer amplifies the high-frequency vibration and transmits the high-frequency vibration to the punch, and the punch is enabled to realize the high-frequency vibration in the vertical direction. And (3) placing the plate to be self-piercing riveted on a die fixed with a press machine base, and driving the rivet to generate extrusion force on the plate to be self-piercing riveted by the press machine motor while the punch vibrates at high frequency so as to finish the ultrasonic vibration assisted plastic forming process.

In the embodiment provided by the invention, the amplitude transformer of the ultrasonic vibration system and the blank holder of the press machine are combined into a whole, namely, the ultrasonic wave emitted by the ultrasonic transducer directly acts on the blank holder, so that the riveting part (namely the periphery of the part where the punch reaches the plate) of the plate can be softened by means of the blank holder, the ultrasonic wave does not need to directly act on the rivet, and the probability of fracture and deformation of the rivet can be effectively reduced.

In the process of forming the above material, effects such as stress reduction, improvement of deformation limit, reduction of surface roughness, and the like can be achieved by applying ultrasonic vibration to the plate material. Specifically, the ultrasonic transducer vibrates at a constant frequency and amplitude, and therefore the binder also mechanically vibrates at a constant frequency and amplitude. The vibration of the edge pressing ring in the loading process can cause small-amplitude periodic unloading and loading phenomena, so that the stress periodically fluctuates, and a stress superposition effect is formed. The unloading behavior under the effect of the stress superposition results in a reduction of the material mean stress. In addition, ultrasonic vibration may promote the development of crystal defects. That is, crystal defects such as vacancies, dislocations, etc. may absorb ultrasonic energy during ultrasonic loading, stimulating dislocation propagation movement, and may also cause stress reduction.

In addition, it should be noted that in the related art, the sheet is horizontally placed on the mold, while in the present embodiment, the sheet may be vertically placed between the mold and the blankholder, and the mold and the blankholder clamp the sheet before the ultrasonic vibration system is started. After the ultrasonic vibration system is started, since the amplitude of the blankholder is small and the frequency is high, it can be considered that the blankholder and the die are continuously kept in a pressing state on the sheet material during the application of the ultrasonic wave, that is, the sheet material does not move relative to the die and the blankholder.

In some embodiments, a second ultrasonic transducer is coupled to the mold;

after step 102 and before step 106, further comprising:

enabling ultrasonic waves emitted by a second ultrasonic transducer to act on the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through a die; the ultrasonic wave emitted by the second ultrasonic transducer is parallel to the surfaces of the at least two plates to be self-piercing riveted, which are in contact with each other.

In the embodiment, the ultrasonic waves emitted by the second ultrasonic transducer connected with the die are applied to the surfaces of at least two plates to be self-piercing riveted, which are in contact with each other, so that the riveting part of the plates to be self-piercing riveted can be softened, the ultrasonic waves do not need to be directly applied to the rivet, and the probability of fracture and deformation of the rivet can be effectively reduced; and welding of different plates to be self-piercing riveted can be realized, which is beneficial to improving the connection strength of the plates to be self-piercing riveted and the corrosion resistance of the plates to be self-piercing riveted.

The second ultrasonic transducer mainly plays a role in ultrasonic metal welding because the ultrasonic wave emitted by the second ultrasonic transducer is perpendicular to the surfaces of at least two plates to be self-punched and riveted, which are in contact with each other. Of course, those skilled in the art will appreciate that the ultrasonic transducer is part of an ultrasonic vibration system, wherein the ultrasonic vibration system includes an ultrasonic generator, an ultrasonic transducer, and a horn. Specifically, the ultrasonic generator converts a power frequency current with a certain frequency into a resonant current with a certain frequency, the resonant current is transmitted to the ultrasonic transducer through an inverse piezoelectric effect, the ultrasonic transducer converts the resonant current into high-frequency vibration, and the amplitude transformer amplifies the high-frequency vibration. In ultrasonic metal welding, the amplitude transformer transmits high-frequency vibration to the surfaces of the plates from the tangential direction, so that the surfaces in contact between two adjacent plates generate relative friction to realize the effect of metal welding. From the perspective of ultrasonic metal welding, the die corresponds to an upper sonotrode and the binder ring corresponds to a lower sonotrode, wherein the upper sonotrode and the lower sonotrode are well known to those skilled in the art and will not be described herein in detail.

In some embodiments, the ultrasonic waves emitted by the first ultrasonic transducer have an effect time on the surface of the sheet material to be self-clinched in contact with the blankholder of not more than 5s.

This is because the ultrasonic wave is usually within 5s (even within 1 s) to generate softening effect on the surface of the plate material, and this increase of the action time does not further increase the softening effect of the plate material, but rather causes heat generation and waste of energy of the ultrasonic transducer, so that the action time is set to be not more than 5s. Preferably, the action time does not exceed 1s.

In some embodiments, after step 106, the self-piercing riveting method further comprises:

After the punch is extruded into the groove, the plate can rebound a little, and in order to ensure the self-piercing riveting quality, the punch is usually required to keep pressure. In the embodiment, the self-piercing riveting quality of the sheet material can be further improved by continuously turning on the first ultrasonic transducer so that the ultrasonic waves act on the surface of the sheet material to be self-piercing riveted, which is in contact with the blank holder, through the blank holder.

In some embodiments, the time for which the first ultrasonic transducer is reactivated may be set to not exceed 3 seconds.

This is because the ultrasonic wave is usually within 3s (even within 1 s) and can guarantee the self-piercing riveting quality of panel (namely avoid the resilience influence of panel), and this increase of action time can not further improve the self-piercing riveting quality of panel, but can lead to ultrasonic transducer heating and waste of energy on the contrary, therefore this action time sets up to be no more than 3s. Preferably, the action time does not exceed 1s.

In some embodiments, the ultrasonic waves emitted by the second ultrasonic transducer are applied to the surface of the at least two sheets to be self-clinched, which is in contact with each other, for a time not exceeding 5s.

and continuing to apply the ultrasonic waves emitted by the second ultrasonic transducer to the surfaces, which are contacted with each other, of the at least two plates to be self-piercing riveted through the die.

After the punch is extruded into the groove, the plate can rebound a little, and in order to ensure the self-piercing riveting quality, the punch is usually required to keep pressure. In the embodiment, the self-piercing riveting quality of the sheet material can be further improved by continuously turning on the second ultrasonic transducer so that ultrasonic waves act on the surfaces, which are in contact with each other, of the at least two sheet materials to be self-piercing riveted through the blank holders.

In some embodiments, the second ultrasonic transducer may be reactivated for no more than 3 seconds.

This is because the ultrasonic wave is usually within 3s (even within 1 s) to ensure the self-piercing riveting quality of the plate (i.e. avoid the impact of the springback of the plate), and this increase of the action time does not further improve the self-piercing riveting quality of the plate, but rather causes the ultrasonic transducer to generate heat and waste energy, so the action time is set to be not more than 3s. Preferably, the action time does not exceed 1s.

The embodiment of the invention also provides a self-piercing riveting device, which comprises a blank holder, a punch, a rivet, a die and a first ultrasonic transducer, wherein the blank holder is connected with the first ultrasonic transducer;

at least two plates to be self-stamped and riveted are arranged between the blank holder and the die, the blank holder and the die are used for pressing the riveting parts of the at least two plates to be self-stamped and riveted, and the punch is used for driving the rivet to extrude the riveting parts of the at least two plates to be self-stamped and riveted;

the ultrasonic wave emitted by the first ultrasonic transducer acts on the surface of the plate to be self-piercing riveted, which is in contact with the blank holder, through the blank holder, and the ultrasonic wave emitted by the first ultrasonic transducer is perpendicular to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder.

In some embodiments, the mold further comprises a second ultrasonic transducer, the mold being connected to the second ultrasonic transducer;

the ultrasonic waves emitted by the second ultrasonic transducer act on the surfaces of the at least two plates to be self-piercing riveted, which are in contact with each other, through the blank holder, and the ultrasonic waves emitted by the second ultrasonic transducer are perpendicular to the surfaces of the at least two plates to be self-piercing riveted, which are in contact with each other.

In some embodiments, the ultrasonic waves emitted by the first ultrasonic transducer are applied to the surface of the sheet material to be self-clinched in contact with the blankholder for a time not exceeding 5s.

In some embodiments, the ultrasonic waves emitted by the second ultrasonic transducer are applied to the surface of the at least two sheets to be self-clinched, which is in contact with each other, for a time of not more than 5 seconds.

It can be understood that the self-piercing riveting device provided in the first embodiment and the self-piercing riveting method provided in the first embodiment are implemented based on the same inventive concept, and therefore, the two have the same beneficial effects, and the beneficial effects of the self-piercing riveting device provided in the first embodiment are not described herein again.

Example two

As shown in fig. 2, an embodiment of the present invention further provides a self-piercing riveting method, including:

200, placing at least two plates to be self-piercing riveted between a blank holder and a die; the punching head and the rivet are arranged inside the blank holder, the blank holder is connected with a first ultrasonic transducer, and the die is provided with a groove matched with the rivet;

202, compressing riveting parts of at least two plates to be self-piercing riveted by using a blank holder and a die;

step 204, enabling ultrasonic waves emitted by a second ultrasonic transducer to act on the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through a die; the ultrasonic wave emitted by the second ultrasonic transducer is parallel to the surfaces of the at least two plates to be self-piercing riveted, which are in mutual contact;

and step 206, the punch drives the rivet to extrude the riveting part of at least two plates to be self-piercing riveted until the groove is completely filled by the plates to be self-piercing riveted and the rivet.

In some embodiments, a first ultrasonic transducer is connected to the blankholder;

after step 102 and before step 106, further comprising:

enabling ultrasonic waves emitted by the first ultrasonic transducer to act on the surface of the plate to be subjected to self-piercing riveting, which is in contact with the blank holder, through the blank holder; the ultrasonic wave emitted by the first ultrasonic transducer is perpendicular to the surface of the plate to be self-clinched, which is in contact with the blank holder.

and continuously applying the ultrasonic waves emitted by the second ultrasonic transducer to the surfaces, which are contacted with each other, of the at least two plates to be self-piercing riveted through the die.

It can be understood that, for the beneficial effects and analysis corresponding to each implementation of the self-piercing riveting method provided in the second embodiment, reference is made to the description of the self-piercing riveting method in the first embodiment, and details are not described herein.

The embodiment of the invention also provides a self-piercing riveting device, which comprises a blank holder, a punch, a rivet, a die and a second ultrasonic transducer, wherein the punch and the rivet are arranged inside the blank holder;

In some embodiments, the ultrasonic wave generator further comprises a first ultrasonic transducer, and the blank holder is connected with the first ultrasonic transducer;

It can be understood that the self-piercing riveting device provided by the second embodiment and the self-piercing riveting method provided by the second embodiment are implemented based on the same inventive concept, and therefore, the two have the same beneficial effects, and the beneficial effects of the self-piercing riveting device provided by the second embodiment are not described herein again.

EXAMPLE III

As shown in fig. 3, an embodiment of the present invention further provides a self-piercing riveting method, including:

step 300, placing at least two plates to be self-piercing riveted between a blank holder and a die; the punching head and the rivet are arranged inside the blank holder, the blank holder is connected with a first ultrasonic transducer, the die is connected with a second ultrasonic transducer, and the die is provided with a groove matched with the rivet;

302, pressing the riveting parts of at least two plates to be self-punched and riveted by using a blank holder and a die;

step 304, enabling ultrasonic waves emitted by the first ultrasonic transducer to act on the surface of the plate to be self-piercing riveted, which is in contact with the blank holder, through the blank holder; the ultrasonic wave emitted by the first ultrasonic transducer is vertical to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder;

step 306, enabling ultrasonic waves emitted by a second ultrasonic transducer to act on the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through a die; the ultrasonic waves emitted by the second ultrasonic transducer are parallel to the surfaces of the at least two plates to be self-piercing riveted, which are in contact with each other;

308, driving the rivet to extrude the riveting part of at least two plates to be self-piercing riveted by the punch until the groove is completely filled by the plates to be self-piercing riveted and the rivet;

step 310, continuing to apply the ultrasonic waves emitted by the first ultrasonic transducer to the surface of the plate to be self-piercing riveted, which is in contact with the blank holder, through the blank holder;

and step 312, continuously performing the action of the ultrasonic waves emitted by the second ultrasonic transducer on the surfaces, which are contacted with each other, of the at least two plates to be self-piercing riveted through the die.

It is understood that step 304 and step 306 may be performed simultaneously or sequentially; step 310 and step 312 may be performed simultaneously or sequentially.

As shown in fig. 4, an embodiment of the present invention further provides a self-piercing riveting apparatus, which includes a frame 10, and a blank holder 1, a mold 2, a first ultrasonic transducer 3, and a second ultrasonic transducer 4 that are disposed on the frame 10, wherein:

the blank holder 1 is connected with the first ultrasonic transducer 3, a punch (not shown in the figure) and a rivet (not shown in the figure) are arranged inside the blank holder 1, the die 2 is connected with the second ultrasonic transducer 4, and the die 2 is provided with a groove (not shown in the figure) matched with the rivet;

at least two plates to be self-piercing riveted (not shown in the figure) are arranged between the blank holder 1 and the die 2, the blank holder 1 and the die 2 are used for pressing the riveting parts of the at least two plates to be self-piercing riveted, and the punch is used for driving the rivet to extrude the riveting parts of the at least two plates to be self-piercing riveted;

the ultrasonic wave emitted by the first ultrasonic transducer 3 acts on the surface of the plate to be self-clinched, which is in contact with the blank holder 1, through the blank holder 1, and the ultrasonic wave emitted by the first ultrasonic transducer 3 is perpendicular to the surface of the plate to be self-clinched, which is in contact with the blank holder 1;

the ultrasonic waves emitted by the second ultrasonic transducer 4 act on the surfaces of at least two plates to be self-clinched, which are in contact with each other, through the blank holder 1, and the ultrasonic waves emitted by the second ultrasonic transducer 4 are perpendicular to the surfaces of at least two plates to be self-clinched, which are in contact with each other.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a …" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A self-piercing riveting method, comprising:

placing at least two plates to be self-riveted between a blank holder and a die; the punching head and the rivet are arranged inside the blank holder, the blank holder is connected with a first ultrasonic transducer, the die is provided with a groove matched with the rivet, and the die is connected with a second ultrasonic transducer;

compressing the riveting positions of at least two plates to be self-punched and riveted by using the blank holder and the mould;

enabling ultrasonic waves emitted by the first ultrasonic transducer to act on the surface of the plate to be subjected to self-piercing riveting, which is in contact with the blank holder, through the blank holder so as to soften the riveting part of the plate to be subjected to self-piercing riveting, which is in contact with the blank holder; the ultrasonic waves emitted by the first ultrasonic transducer are perpendicular to the surface of the plate to be self-clinched, which is in contact with the blank holder;

the ultrasonic wave emitted by the second ultrasonic transducer acts on the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through the die, so that the second ultrasonic transducer has the function of ultrasonic metal welding, and the corrosion resistance of the plates to be self-piercing riveted is improved; the ultrasonic waves emitted by the second ultrasonic transducer are parallel to the surfaces of the at least two plates to be self-piercing riveted which are in contact with each other, the action time of the ultrasonic waves emitted by the second ultrasonic transducer on the surfaces of the at least two plates to be self-piercing riveted which are in contact with each other is not more than 1s, the die is equivalent to an upper sonotrode from the angle of ultrasonic metal welding, and the blank holder is equivalent to a lower sonotrode;

driving the punch to drive the rivet to extrude riveting parts of at least two plates to be subjected to self-piercing riveting until the groove is completely filled by the plates to be subjected to self-piercing riveting and the rivet;

continuously acting the ultrasonic waves emitted by the second ultrasonic transducer on the surfaces, which are contacted with each other, of at least two plates to be self-piercing riveted through the die; wherein the second ultrasonic transducer is applied again for no more than 1s.

2. The self-piercing riveting method according to claim 1, characterized in that the action time of the ultrasonic waves emitted by the first ultrasonic transducer on the surface of the sheet to be self-piercing riveted in contact with the blankholder is not more than 5s.

3. The self-piercing riveting method according to any one of claims 1-2, wherein after the punch drives the rivet to squeeze the riveting part of at least two plates to be self-piercing riveted until the groove is completely filled by the plates to be self-piercing riveted and the rivet, the method further comprises the following steps:

4. A self-piercing riveting device is applied to the self-piercing riveting method according to any one of claims 1 to 3, and comprises a blank holder, a punch, a rivet, a die and a first ultrasonic transducer, wherein the blank holder is connected with the first ultrasonic transducer, the punch and the rivet are arranged inside the blank holder, and the die is provided with a groove matched with the rivet;