BRPI0907795B1 - electro-hydraulic device with electronic control to deform fastening elements - Google Patents

Abstract

The electro-hydraulic pistol device (100) comprises: a first electric micro-motor (1 ), for setting in right-wise or left-wise rotation a threaded rod (2), respectively for engaging or disengaging the rod (2) from a rivet (3); a hydraulic system (4) in which a fluid (F) pushes a cursor (40), associated to the rod (2) for impressing thereon an axial translation which causes plastic deformation of a predetermined portion of the rivet (3), such as to block the rivet (3) to a corresponding wall (P); a second electric micro-motor (5), for commanding a piston (50) destined to compress the fluid (F). An electrical circuit (6) is associated to the above organs, which electrical circuit (6) is managed by a control unit (60), to which are connected: a first micro-switch (61) activated by the rod (2) for activation of the first micro-motor (1) in a right-wise direction; a second micro-switch (62), destined to be activated by a trigger (63) after deactivation of the first micro-switch (61), for activating the second micro-motor (5), first in a direction, for compressing the fluid (F), and then in another direction, for reducing the pressure of the fluid (F), as well as for activating, in phase relation, the first micro-motor (1) in a left-wise rotation; supply means (7) for the circuit (6) and the micro-motors (1, 5). The left-wise rotation of the first micro-motor (1) and the rod (2) proceeds as long as the trigger (63) is kept pressed.

Description

“ELECTRO-HYDRAULIC DEVICE WITH

ELECTRONIC CONTROL TO DEFORM FIXING ELEMENTS ”

TECHNICAL FIELD [001] The present invention relates to the technical sector of riveting guns with reference, in particular, to servo-assisted pistols used for cylindrical rivets with a particularly threaded axial hole, a contact collar on their head and a specially weakened part in which plastic deformation occurs.

STATE OF THE TECHNIQUE [002] The rivets are intended to join two walls with stability, for example, instead of spot welding, or to constitute a threaded adapter sleeve of adequate rigidity for structures made of very soft or very thin materials a in order to mold threads with sufficient strength.

[003] The rivets described above can have considerable dimensions and, for their application, it is necessary to make use of the appropriate equipment, which must be able to exert a high compression force on them.

[004] A known type of gun riveting, made by the same applicant under the application of Italian patent for industrial inventions No. BO2007A000311, comprising a body and a handle which houses:

a pneumatic motor to rotate a threaded rod to the right or left, respectively, to engage it with the threaded axial hole of one of the rivets or to disengage it;

a hydraulic system to generate the axial translation of the motor-rod assembly in order to cause the plastic deformation of a predetermined part of the rivet in order to fix it to a structure;

a pneumatic thrust amplifier that activates a piston to compress fluid in the hydraulic system;

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2/11 a pneumatic system comprising: an auxiliary valve activated to be opened by the stem; a main valve activated to be opened by a trigger;

a hydropneumatic exchange valve connected to the hydraulic and pneumatic systems comprising: a first means for detecting the pressure of the hydraulic fluid; a second means for passing the compressed air supply from the pneumatic buoy amplifier to the air motor after reaching a predetermined maximum pressure of the hydraulic fluid;

an emergency control to make the air motor turn to the left.

[005] The pistol works like this:

the rivet is placed in the hole arranged for it in the structure with the related collar in contact with it or, alternatively, the rivet is placed manually in front of the pistol rod;

the rod is placed in the axial hole of the rivet until the beginning of its thread, thus determining an axial thrust on the rod towards the gun body, which causes the auxiliary valve to open, an auxiliary valve that allows air compressed is sent to the engine, causing it to turn to the right in order to screw it to the rivet; when his collar comes into contact with the front head of the body, the auxiliary valve automatically closes and the engine stops;

by pressing the trigger, the main valve opens, which allows compressed air to be sent to the buoyancy amplifier through the hydropneumatic exchange valve with the consequent increase in the pressure of the hydraulic fluid and the beginning of the axial translation of the motor-rod assembly;

keeping the trigger pressed, the translation continues, generating a progressive compression of the rivet, which is then deformed in an external direction in the weakened part, defining an annular edge that

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3/11 adheres to the surface of the structure opposite the structure on which the collar rests, thus determining the obstruction of the rivet;

still keeping the trigger pressed, when reaching the maximum pressure determined by the hydraulic fluid, the second means of the hydropneumatic exchange valve intervenes and interrupts the entry of compressed air towards the thrust amplifier and sends it to the pneumatic motor, causing it turns to the left; at the same time that the air contained in the buoyancy amplifier is discharged in the external environment;

the rotation of the motor to the left is transmitted to the threaded rod, which is released from the screw, now attached to the structure;

the operator releases the trigger when the rod disengages from the rivet.

[006] The riveting gun described above works very well, but requires a source of compressed air from which to feed; therefore, it is not possible to use it when an air source is not available.

[007] FR 2,779,670 discloses an electro-hydraulic pistol device according to the preamble of claim 1.

DISCLOSURE OF THE INVENTION [008] The purpose of the present invention is to offer an electro-hydraulic pistol device with electronic control to deform fastening elements, which, therefore, does not require connection to a compressed air source.

[009] Another objective of the invention is to offer an electro-hydraulic pistol device that has an operational logic entirely similar to that of the known pistol described in the introduction above.

[0010] Yet another objective of the invention concerns the desire to offer an electro-hydraulic pistol device that can be realized in several varied embodiments, different in the type of

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4/11 electrical supply provided and / or in the constructive model, with components that can be housed in the body and the handle or that can be external to them.

[0011] An additional objective of the invention is the possibility of offering particularly compact and light versions of the electro-hydraulic pistol device thanks to the external location of the components.

BRIEF DESCRIPTION OF THE DRAWINGS [0012] The characteristics of the invention will be better understood by reading the description of the preferred embodiments below as defined in the appended claims and with the help of the accompanying figures of the drawings, in which:

Figure 1 illustrates an embodiment of the hydroelectric gun device of the present invention in a schematic and sectional side view;

figure 2 is a section taken along the plane II-II of figure 1;

figure 3 is a section taken along the plane III-III of figure 1;

figures 4 to 11 illustrate views similar to figure 1 with the electro-hydraulic device in the most important stages of operation.

BEST MODE FOR CARRYING OUT THE INVENTION [0013] With reference to the figures in the drawings, the number 100 indicates a first embodiment of the electro-hydraulic pistol device of the invention as a whole; in the following description, for the sake of simplicity, we will call device 100 only a pistol.

[0014] The pistol 100 comprises a body 101 and a handle 102, within which are the following components:

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5/11 a first electric micromotor 5, a second electric micromotor 1 and a hydraulic system 4, the second electric micromotor 1, to turn left or right, thanks to the first transmission medium 11, a threaded rod 2, respectively, for engage it with the threaded axial hole 3A of one of the rivets 3 or disengage it from it, the hydraulic system 4 comprising a cylinder 51 containing a fluid F and connected to a chamber 41, where a slider 40 slides, which imposes the translation axial axis of the rod 2 in order to cause the plastic deformation of a predetermined part of the rivet 3, such as to secure it to a corresponding wall P and the first electric micromotor 5 to control, through the second means of transmission 52, the displacements round-trip piston 50, which compresses fluid F of the hydraulic system 4 in cylinder 51 during the flow;

an electrical circuit 6 comprising the following: a control unit 60; a microswitch 61 activated by stem 2 to cause the second micromotor 1 to rotate stem 2 to the right; a second micro-key 62 activated by a trigger 63 to activate the first micromotor 5, firstly, in one direction and then in the other, and in a phased relation determined by the control unit 60, to activate the second micromotor 1 in order to rotate to the left;

batteries 7 connected to an ON / OFF switch, not illustrated, to supply electrical power to the electrical circuit 6 and, therefore, to the first 5 and second micromotors 1.

[0015] The pistol 100 also includes an emergency control button, not illustrated in detail, but preferably arranged in a position and / or configuration protected against accidental activation, the button being connected to electrical circuit 6 and intended for activate the second micromotor 1 so that the stem 2 turns to the left as we will describe below.

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6/11 [0016] The first transmission medium 11 is composed, for example, by a series of gears that also function as speed reducers; preferably, said means 11 causes the second micromotor 1 and the stem 2 to rotate in the same direction (figures 2 and 3).

[0017] The second transmission means 52 is composed, for example, by an epicyclic gear reducer.

[0018] Next, we will describe the operation of the pistol 100 for the application of a rivet 3 to a wall P, starting from the inoperative position of figure 4, where:

micromotors first 5 and second 1 are stationary;

the pressure in the hydraulic system 4 is at a minimum, with the piston 50 in the lowered position inside the cylinder 51 and the forward cursor 40 in the chamber 41 towards the front head 101a of the body 101 as a result of the action of an associated counter 42 spring ;

the key connected to the batteries 7 is in the ON position.

[0019] We place the rivet 3 in the hole of the wall P with the associated collar 3B in contact with the wall or, alternatively, we place the rivet 3 manually in front of the rod 2 of the piston 100 (see figure 4).

[0020] Similar to the known riveting gun mentioned in the introduction to this document, we insert the rod 2 in the axial hole 3A of the rivet 3 until the beginning of its thread, thus determining an axial thrust on the threaded rod 2 towards the body 101 pistol 100, which activates the first micro-key 61; the approach of the contact between them sends a signal to the control unit 60 to activate the second micromotor 1 in a suitable direction in order to turn the stem 2 to the right to screw it to the rivet 3.

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7/11 [0021] When the collar 3B of the rivet 3 comes into contact with the front head 101A of the body 100, the stem is once again brought into the external environment, releasing the micro-key 61 and thus causing the second micromotor 1 stop (figure 5).

[0022] By pressing the trigger 63, the second micro-key 62 is activated and the control unit 60 starts the automatic operational cycle of the pistol 100 (figure 6).

[0023] Then, the first micromotor 5 is activated in the appropriate direction in order to determine the forward displacement of piston 50 in cylinder 51, with a consequent increase in the pressure of hydraulic fluid F in chamber 41 of cursor 40 (figure 7 ).

[0024] Keeping the trigger 63 pressed, piston 50 continues to rise, at the same time that the pressurized fluid F overcomes the resistance of the counterposing spring 42 and pushes the cursor 40 so that it recedes together with the threaded rod 2 related.

[0025] The translation continues, causing a progressive compression to the rivet 3, which deforms towards the outside in the weakened part in order to define an annular edge 3C that adheres to the surface of the wall P opposite to the surface on which the collar 3B rests, thus generating the rivet 3 obstruction (figure 8).

[0026] The increase in pressure in the hydraulic system 4 increases the resistance to lift the piston 50, which leads to a proportional increase in the energy absorption by the first micromotor 5.

[0027] The control unit 60 monitors the value of this absorption at all times, since the force exerted on the rod 2 to deform the rivet 3 in relation to it by means of suitable parameters.

[0028] Based on the maximum force with which the gun must be calibrated, the maximum absorption peak at which the first

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8/11 micromotor 5 has to arrive and this data is stored in control unit 60.

[0029] When the instantaneous absorption detected equals the maximum predicted value, and with that, the predetermined deformation thrust is reached, the control unit 60 inverts the rotation of the first micromotor 5, with the consequent inversion of the movement of the piston 50 (figure 9).

[0030] This leads to a sharp drop in the pressure of the hydraulic fluid F with the consequent interruption of the retraction of the cursor-stem assembly and, therefore, of the tension on the rivet 3.

[0031] As the piston 50 continues its descent due to the action of the first micromotor 5, the contrast spring 42 once again overcomes the force determined by the pressure of the fluid F and advances the cursor 40 and the stem 2.

[0032] The control unit 60, in an appropriate phasic relationship with the descent of piston 50, also starts the second micromotor 1, defining that the threaded rod 2 turns to the left so that it detaches from the rivet 3, which, now , is attached to the wall P (figure 10).

[0033] The first micromotor 5 remains in motion until piston 50 reaches the lowered initial position, after which it is automatically deactivated by control unit 60 (see figure 10 again); the signal confirming arrival at the position can be sent by an end-of-travel sensor (not shown) or by the consequent increase in the absorption of the first micromotor 5 when intercepted by an end-of-travel mechanical stop 53 integrated with the piston 50.

[0034] The rotation of the second micromotor 1, on the other hand, continues as long as the trigger 63 is lowered, so that the rotation of the rod 2, to detach itself from the newly applied rivet 3, continues for the time decided by the operator.

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9/11 [0035] When releasing the trigger 63, with the second stop of the second micromotor 1, the programmed operation is concluded (figure 11).

[0036] At this point, gun 100 returns to the condition described in relation to figure 4, with control unit 60 predisposed for a new cycle.

[0037] Therefore, ideally, a particularly capable operator can synchronize the disengagement of the rod 2 with the interruption of the second micromotor 1 in order to prepare the gun 100 immediately for engagement with another rivet 3 already positioned on the wall P.

[0038] If, for some error or other reason, trigger 63 is released before disengagement of stem 2, it is possible to complete the unscrewing by pressing the emergency command in order to reactivate the second micromotor 1 with a new rotation of the stem 2 to the left.

[0039] It is worth mentioning that pistol 100, as described, does not suffer in the slightest from any handling error that may happen if, after the trigger 63 is released, pressure is exerted on it again.

[0040] It is possible to program the control logic of the control unit 60 to continue the interrupted cycle, for example, if the release occurs during the rivet 3 deformation stage.

[0041] If the handling error is in the final unscrewing stage, with a subsequent pressure on the trigger 63, instead of activating the emergency control, the gun repeats the automatic traction cycle on rod 2 without exerting undesired tension on the rivet 3 applied since, upon reaching the maximum pressure of the preceding fluid F, the control unit 60 interrupts the action and starts unscrewing, so that the only disadvantage is that of losing a brief time interval.

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10/11 [0042] Other embodiments of the electro-hydraulic pistol device are contemplated regardless of the one illustrated and described in this document.

[0043] In a second embodiment, not shown, the batteries 7, as well as, possibly, the control unit 60, can be housed in a module external to the pistol body in order to reduce the weight and size of it to facilitate its use.

[0044] In a third embodiment, also not illustrated, instead of using batteries, the electric energy is powered by a network, thanks to the interposition of a suitable transformer / rectifier, with the objective of obtaining unlimited working autonomy, together (also in this case) with a considerable reduction in weight.

[0045] In fact, with reference to the last solution, the device's total independence from external energy sources is lost, but it is quite evident that it is much easier to arrange an outlet available than a source of compressed air.

[0046] In yet another embodiment, not illustrated, we combine the constructive characteristics of the two aforementioned embodiments, thus obtaining a module external to the gun body that contains, in addition to the batteries and the control unit, the transformer / rectifier for the supply by through an electrical network and possibly a device to recharge the batteries.

[0047] By reading the description above, it is possible to understand that the electro-hydraulic pistol device completely fulfills the objectives set, in particular that of obtaining an operating logic totally similar to that of the pistol of known type mentioned in the introduction of this document without the need for any source of compressed air.

[0048] The construction possibilities, such as the possibility of choosing the means of electrical operation, show that it is easy to define several construction variations without bringing any negative effect to the

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11/11 functioning of the device, variations may respond to needs that would otherwise remain ignored.

[0049] Thanks to the external positioning of components, such as batteries, it is possible to achieve considerable benefits in terms of compactness and lightness of the device, leading to evident advantages during its use.

Claims (15)

1. - Electro-hydraulic pistol device for the deformation of fasteners of a type comprising: a trigger (63), an electrical circuit (6) and a means of supplying electrical energy (7); a threaded rod (2) that engages the threaded axial hole (3A) of a rivet (3); a hydraulic system (4) comprising means (40), associated with the rod (2), which generates the axial translation of the threaded rod (2), by the action of the hydraulic fluid (F) of the system (4), to cause plastic deformation of a predetermined part of the rivet (3), such as to attach the rivet (3) to a corresponding wall (P), a first electric micromotor (5) to control the displacement of compression and discharge of a piston (50) arranged inside a cylinder (51) to exert, respectively, the increase in fluid pressure (F) of the hydraulic system (4) up to a predetermined maximum value and its reduction; characterized by still understanding: a second electric micromotor (1) to cause the threaded rod (2) to turn to the right or to the left, respectively, to engage or disengage it from the threaded axial hole (3A) of the rivet; an electrical circuit (6) managed by an electronic control unit (60), which comprises a first microswitch (61) that is activable by the stem (2) to activate the second micromotor (1) so that the stem (2) turn to the right and a second microswitch (62) can be activated by the trigger (63) after deactivating the first microswitch (61) to activate the first micromotor (5), firstly, in one direction causing the piston compression run ( 50) and then on the other causing the piston discharge operation (50), as well as to activate the second micromotor (1) in phase relation with the activation of the said piston discharge displacement (50) so that the rod (2) turn to the left; Petition 870190079820, of 16/08/2019, p. 35/37 2/3 wherein said feeding means (7) are adapted to supply electrical energy to the electrical circuit (6) and, through it, to the first micromotor (5) and the second micromotor (1). 2. - Device, according to claim 1, characterized by the fact that the medium (40) is composed of a sliding slide inserted in a chamber (41) and subjected, on one side, to the action of a spring of counterposition (42) and, on the other side, to the action of the hydraulic fluid (F) of the system (4). 3. - Device according to claim 1, characterized by the fact that the control unit (60) is provided with a means to instantly detect the energy absorption by the first micromotor (5) and a calculating means for relating an absorption value with the hydraulic fluid pressure (F). 4. - Device according to claim 1, characterized by the fact that the first transmission means (11) is arranged between the second micromotor (1) and the threaded rod (2). 5. - Device according to claim 4, characterized by the fact that the first transmission means (11) consists of several gears that reduce a series of revolutions from the input to the movement output. 6. - Device according to claim 1, characterized by the fact that the second transmission means (52) is arranged between the first micromotor (5) and the piston (50). 7. - Device according to claim 6, characterized by the fact that the second transmission medium (52) is composed of an epicyclic reducer. 8. - Device, according to claim 1, characterized by including an emergency command operated by a button connected to the electrical circuit (6) and which activates the second micromotor (1), causing the rod (2) to turn to to the left. Petition 870190079820, of 16/08/2019, p. 36/37 3/3 9. - Device, according to claim 1, characterized by the fact that a bidirectional switch, whose positions serve, respectively, to connect the power supply (7) to the electrical circuit and disconnect it, is connected to the supply (7) to and from the electrical circuit (6). 10. Device according to claim 1 or 9, characterized by the fact that the feeding means (7) is located inside the body (101) and the handle (102) of the device (100). 11. Device according to claim 1 or 9, characterized by the fact that the supply means (7) is located inside a module external to the device (100). 12. Device according to claim 1, 9, 10 or 11, characterized by the fact that the supply medium (7) is composed of batteries. 13. - Device according to claim 1, 9 10 or 11, characterized by the fact that the supply medium (7) consists of a transformer / rectifier that can be connected to an external electricity source. 14. - Device according to claim 1, characterized by the fact that the control unit (60) is located inside the body (101) and the handle (102) of the device (100). 15. - Device, according to claim 1, characterized by the fact that the control unit (60) is located inside a module external to the device (100).