WO1989010808A1

WO1989010808A1 - A method and an apparatus for joining two or several overlaying sheet formed members together, metal or non-metal

Info

Publication number: WO1989010808A1
Application number: PCT/SE1989/000250
Authority: WO
Inventors: Luciano Gubbiotti
Original assignee: Attexor Equipements S.A.
Priority date: 1988-05-07
Filing date: 1989-05-08
Publication date: 1989-11-16
Also published as: SE8801755D0; AU3577789A; KR900700206A

Abstract

Method for joining together two or several overlaying sheet formed members (4, 5), metal or non-metal, at which a coaxial arrangment of a punch (2), a matrix (1) and an anvil (3) are caused to cooperate by means of their relative movements. The punch (2) and anvil (3) are caused by means of applied forces to carry out a first part of a movement coaxially towards said matrix (1) to a first relative position between punch and matrix. The punch starts to cut through the sheet formed members along part of its perimeter. During a second part of the movement towards said matrix (1) to a second relative position between the punch (2) and the matrix (1) which is dependent on the applied forces, the thickness, the number and the material of the sheet-formed members (4, 5), the punch ends the cutting operation and said anvil, in cooperation with said matrix, deforms said sheet-formed members outside the cut-out and formed portions along the edge of said portions.

Description

A METHOD AND AN APPARATUS FOR JOINING TWO OR SEVERA OVERLAYING SHEET FORMED MEMBERS TOGETHER, METAL OR NON METAL

.ECHNICAL FIELD

This invention relates to methods and apparatuses fo joining two or several overlaying sheet formed member together, metal or non-metal.

BACKGROUND ART

It is well known that a pair of overlaying metal members could be joined together by e.g.lancing and forming a part of one member through an unblanked part of the other member and thereafter staking the lanced and formed part of the one member to an adjacent surface of the other member to secure the members together in overlaying relation.

For example the US-A-3 924 378 shows such a joining operation carried out by means of an apparatus having two separately actuateable rams, one of the rams carrying a lancing and forming die and the other ram carrying a flattening punch or anvil whereby the one ram performs the lancing and forming operation and the other ram performs the staking operation. The apparatus is provided with adjustment means so that the upper sheet or sheets of the displaced section is not engaged by the downwards moving flattening punch until the lowermost sheet of the displaced section is uncovered by the upwardly moving die so as to allow the lower sheet of the displaced section to be spre while the upper sheet or sheets are still confined by t die. Thus, said adjustment means must be operated f different thickness of the sheets,

US-A-4 035 901 shows an apparatus having a sing reciprocating head provided with a first means, i.e., die, to perform the lancing and forming step on a fir stroke of the head and provided with a second means, i.e an anvil, that performs the staking operation on the seco stroke of the same head. When the thickness of one several of the sheets to be joined together or the materi of the sheets is changed the stroke length of the first a the second strokes must be adjusted.

GB-A-1 603 231 shows another machine for making a joint the above type. In this machine the moving head compris the punch which in a first stroke pierces the shee against the die placed underneath said sheets. Before t second stroke the die as well as the anvil are axial repositioned by means of holding means having inclin plane surfaces. If the thickness of the sheets is chang the reposition movement must be adjusted.

The above examples of prior art all disclose systems havi a relatively simple one-piece, non-expansible die. T corresponding machines are in principle of the two-stro type. The second stroke is carried out with the deform sections of the sheets at least partly outside the die.

However, other systems and apparatuses operating with on one stroke are known in which the die is lateral expansible. In this type of apparatuses the second part the joint-forming-process takes place inside the die. US-A-4 459 735 discloses an apparatus and a method of th type. By necessity the design of the die is much mo complicated in a system like this and the choice material for the die might be critical. Thus the li expectation for such a die is comparatively low which mak the maintenance costs high for the tool. In addition o and the same die cannot be used if the thickness of t sheets is changed.

The process for forming a joint of the type mentioned abo could be divided into two phases. The first phase is t lancing phase during which the punch, along part of it circumference cuts through the two or several sheets.

All the above mentioned methods and apparatuses carry ou the subsequent deforming operation on the lanced and form portions of the sheet or sheets.

During this second phase the movement of the punc continues and the lateral deformation of the lanced an formed portions of the sheets starts. The applied force increase considerably during this phase, and it is in fac these forces which to a great extent decide the dimension of the machine or tool.

DISCLOSURE OF THE INVENTION

One object of the present invention is to provide a apparatus for joining together two or several overlayin sheet-formed members in a one stroke process whic apparatus is able to make high quality joints with lowe energy input.This means for instance that an apparatus fo making joints in sheets of a specified thickness an quality could be made smaller and lighter than heretofore

Another object is to provide a mechanically more simpl system. Our invention which provides a solution to the sa technical problems is characterised according to t appended claims.

BRIEF DESCRIPTION OF THE FIGURES

Other objects, uses and advantages of this invention a apparent from the reading of this description whi proceeds with reference to the accompanying drawin forming part thereof and wherein.

Figure 1 shows the relative position of a punch and a matrix during a joint forming operation in an apparatus according to this invention

Figure 2 shows schematically a hand-held tool according to the inventive principle with a suitable control and power system

Figure 3 shows a perspective view of part of an integrated punch and anvil and a cooperating matrix

Figure 4 shows in perspective a joint which could be produced by means of the inventive apparatus

Figure 5 shows a section through a joint of the type shown in figure 4

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows the relative positions of a punch 2 and matrix 1 before the joining operation (A) , at the end o the lancing phase (B) and at the end of the deformati phase (C) in an apparatus according to the invention. The movement between the two units is relative which mea that anyone of the units could be fixed in the apparat and the other one moving or both moving. In the describ embodiment we assume the matrix 1 to be fixed in th apparatus. The sheets 4 and 5 rest in contact with t protruding portion 7 of the matrix 1 during the whol operation.

In figure IB the punch has cut through the two sheets alon part of its perimeter. The anvil 3 which is axially fixe to the punch has just made contact with the upper sheet 4.

In figure 1C the lateral deformation of the sheets alon the edges of the opening cut through the sheets starts i the direction in which the counterforces are weakest i.e inwardly towards the punch. The punch which is provide with a slit 6 to its axis will be laterally deformed During this phase the tip portion of the punch will slid against the lanced and formed portion of the sheet 4. Th stiffness of the punch in the lateral direction is mainl dependent on the geometry and material of the punch. Wit the other parameters given the length of the slit 6 coul be used to control this stiffness. The width of the slit which need not be constant along its length or e ty, must depending on the material of the sheets, be chosen in suc a way that enough space is given to the lateral expansio of the sheets.

The final position between the punch and the matrix whic is closely related to the quality of the joint could fo instance be made dependent on the force applied to th punch.

one set of punch, matrix and anvil allows a certain range of thickness and material of the sheets. Outside this rang another set of units could be used or they could b adjusted appropriately. As said above, the anvil is axiall fixed to the punch during the operation. This could b achieved by making the anvil and the punch in one piece, a is shown in figure 3. In order to make these units axiall adjustable, however, they could be assembled together a shown in figures 1 and 2. An easy way to adjust these unit relative to each other will be described with reference t figure 2. The dimensions of the protruding portions 7 o the matrix, especially the height and the width, ar important for achieving a good joint. In an advantageou embodiment of the invention the height of the portions could be chosen so that the sheet 5 during a part of th deformation phase is pressed against the flat portion o the matrix 1 around the portion 7. The flat portion of th matrix thereby gives support to the sheets to minimize th deformation of the same outside the joint.

Figure 2 shows an embodiment of the invention in the for of a hand-held tool provided with a suitable control an power system. In the body 22 of the tool a matrix 1 i fixed. Opposite to this matrix a cylinder-piston assembl 23,8 is arranged as driving unit for a punch 2 which i mounted in a cavity in the piston coaxially with th matrix. The piston is spring loaded to its initial positio by means of the spring 9. The front portion of the piston around the opening of the cavity constitutes the anvil 3 The relative position between the anvil and the punch coul be arranged to be adjustable.

in the same figure a simple embodiment of a control an power system is shown. The power is in this case taken fro a pneumatic pressure source (not shown) connected to inpu 14. The handle 10 of the tool is provided with an actuato in the form of a manually operated three way/ two position normally closed valve 11. A pressure controlled valve o the same type is inserted in the pneumatic conduit between the input 14 and a pneumatic-hydraulic booster 1 At the output from the oil chamber 20 of the booster t hydraulic conduit 17 feeds high pressure oil to t cylinder 23 of the tool. When the valve 11 is actuat pneumatic pressure is applied to the control input of t valve 13 which opens and conducts pressure to the boost and the tool carries out a stroke. When the actuator 11 released the valve 13 will close again and the pneumat pressure from the booster 20 will be released in t reverse direction through the conduit 16 and said valv This means that the spring 9 will be able to drive t piston 8 back to its initial position forcing the hydraul fluid back through the conduit 17 to the reservoir 20 the booster.

The drive system for the relative movement of the punch a the matrix as well as the control and power system described above are of course only examples of suc systems. The drive system could for example be a simpl manually operated mechanical system or a cam actuate system for stationary machines. Many other configuration for the pneumatic-hydraulic control and power system coul of course also be envisaged. The pressure booster 20 coul for instance be substituted by a hydraulic pump driven b an electrical motor in which case the actuator 11 of cours would be electrical.

Figure 3 shows part of an integrated anvil and punch and cooperating matrix. With design of the cooperating unit according to this principle a joint according to figures 1 4 and 5 could be produced.

Examples of sections through a joint according to figure are shown in figure 5. The first example i.e. the one o figure 5A, refers to a joint having impressions 21 alon the lanced and formed portions of the sheets only on on side. A flat matrix without the protruding portions 7 ha to be assumed.

5 An alternative is illustrated in figure 5B. An especiall good joint is shown in figure 5C with a good floating o the material of both sheets behind the lanced and forme portions.

10 The joint of figure 5D has been achieved by means of matrix having specially formed protruding portions 7, whic deforms the adjacent sheet favorably. Several other suc protruding portions could be envisaged.

15 It is to be noted that all the above examples of th joints, achieved by the method and the apparatus accordin to the invention, have their essential deformation zones i the sheets along the edge of the lanced portions and not i the lanced and formed portions as such. In this way th

20 area of the sheets and the corresponding volume of shee material which has to be deformed to make a good join could be kept to a minimum which in its turn means that th forces which have to be applied to make the joint are als kept to a minimum. As a consequence the volume and weigh

25 of a corresponding tool will be low which is especiall interesting for a hand-held tool.

30

Claims

1 Method for joining together two or several overlayi sheet formed members(4,5) , metal or non-metal,at which coaxial arrangement of a punch(2) ,a matrix(l) and anvil(3) are caused to cooperate by means of their relati movements

characterised in that it comprises the following steps

said overlaying sheet formed members(4,5) are plac between the punch(2) and the matrix(l),

said punch(2) and anvil(3)/(or matrix 1) are/is caused means of applied forces to carry out a first part of movement coaxially towards said matrix (1) (or punch 2 an anvil 3) to a first relative position between punch a matrix, during which part of the movement said punch start to cut through the sheet formed members along part of it perimeter,

said punch(2) and anvil(3)/(or matrix 1) are/is caused b means of applied forces to carry out a second part of th movement towards said matrix(l) (or punch 2 and anvil 3) t a second relative position between the punch(2) and th matrix(l) which is dependent on the applied forces, th thickness, the number and the material of the sheet-forme members(4,5) , during which second part of the movement sai punch ends the cutting operation and said anvil, i cooperation with said matrix, deforms said sheet-forme members outside the cut-out and formed portions along th edge of said portions. 2 Apparatus for carrying out the method according t claim 1 for joining together two or several overlayin sheet formed members, metal or non-metal, comprising coaxial arrangement of a punch(2), a matrix(l) and a anvil(3), at least the punch and the matrix being arrange moveable relative to each other

characterised in that

the punch(2) and anvil(3) are arranged to carry out, whe actuated, a first part of a movement coaxially towards sai matrix(l) to a first relative position between punch an matrix,

said punch and anvil are arranged to carry out a secon part of said movement towards said matrix to a secon relative position between punch and matrix which i dependent on the applied forces, the thickness, the numbe and the material of the sheet formed members for deformin in cooperation with said matrix said sheet-formed member outside the cut-out and formed portions along the edge o said portions.