EP2390059B1 - Blind rivet nuts setting device - Google Patents

Description

The invention relates to a Blindnietmuttern-setting tool with a housing in which a tie bolt is arranged rotatably and axially movable, which protrudes at least with a threaded portion of the housing, and with a pneumatic-hydraulic pressure booster, a pneumatic cylinder and a hydraulic cylinder wherein a pressure-controlled switching valve is provided which connects the pneumatic cylinder with an outlet channel in a first position and the pneumatic cylinder with a pressure supply in a second position. Such a Blindnietmuttern-setting tool is for example from the GB 2 175 231 A known. Other blind rivet setting tools are from the WO 2008/132576 A3 as well as from the WO 99/04917 known. Blind rivet nuts are fasteners that are to be arranged in an opening, for example in a borehole, of a more or less thin-walled sheet metal. The blind rivet nuts provide an internal thread available and thus allow a screw on sheets whose wall thickness is not sufficient to form a thread. A blind rivet nut setting tool is used to set the blind rivet nut. In this case, the blind rivet nut, which has a hollow cylindrical rivet shank in the undeformed state, at one end of a radially extending setting head is formed and at the other end an internal thread is formed, screwed with the setting head first on the threaded portion of the tension bolt. The internal thread of the blind rivet nut and the external thread in the threaded area of the draw bolt must correspond to this.

The blind rivet nut is then inserted with the rivet shank in the opening until the setting head rests. By commissioning the Blindnietmuttern-setting tool then the tension bolt and thus the threaded portion is axially moved backwards from the blind rivet nut and the sheet, whereby a compression of the rivet shank takes place. The blind rivet nut is then held captive in the opening.

To remove the blind rivet nut setting tool from the set blind rivet nut, the draw bolt is relieved and rotated in the direction of twisting. The blind rivet nut setting tool is then available for a new setting process.

Out DE 698 06 161 T2 a pneumatic-hydraulic riveting device is known, wherein a tension bolt with a threaded portion is moved axially by means of a pneumatic-hydraulic pressure booster. The pneumatic-hydraulic pressure booster has a pressure supply to which a net air pressure can be applied. The pneumatic-hydraulic pressure booster transfers the net air pressure several times to a hydraulic oil, which acts on the tension bolt in the axial direction. By actuating an actuating element, the setting process is started. In this case, a valve is opened, whereby a piston is displaced, so that the required for the setting process air supply to the pneumatic-hydraulic pressure booster takes place. When a predetermined stroke has been performed or a maximum set force is reached, air is released so that a new displacement of the piston takes place. The pneumatic-hydraulic pressure booster is disconnected from the pressure supply. The air contained in the pneumatic cylinder compressed by the oil pressure is directed to a pneumatic motor so that it rotates the tie bolt in the direction of twisting.

With this solution, the complete setting process runs automatically and can not be interrupted. It is necessary that the actuator is released after a short press, which is ensured by a complex construction of the actuator. Since the control of Abdrillbewegung the pneumatic motor is carried out with the air contained in the pneumatic cylinder, a partial deflation of the air to depressurize the draw bolt is first required before the pneumatic motor, the tension bolt can turn. As a result, a relatively long break occurs during each setting operation before twisting, which is often perceived as disturbing.

The invention is based on the object to avoid these disadvantages.

According to the invention this object is achieved in a blind rivet setting tool of the type mentioned above in that the switching valve switches upon actuation of an actuating element in the second position, wherein in the second position, a control line having a passage to the environment, via a throttle and the switching valve is connected to the pressure supply, wherein the control line is closed upon reaching a setting stroke and / or a setting force, wherein a pressure in a control chamber of a pressure-controlled control valve which is connected via a throttle to the pressure supply to a first control surface of the control valve in the direction of acts first switching position and a pressure in the control line acts on a second control surface of the control valve in the direction of a second switching position, wherein the control chamber is depressurized upon actuation of the actuating element, wherein in the second switching position, a motor line of a pneumatic motor s are connected for the withdrawal of a blind rivet nut from the tie bolt and a switching channel of the switching valve to the pressure supply, whereby the switching valve switches to the first position.

By actuation of the actuating element so the switching valve switches to the second position, in the
the pneumatic cylinder is connected to the pressure supply, so that the setting process is started. The actuator can remain pressed. At the same time, by switching the switching valve to the second position, a control line is connected to the pressure supply, and the control line is closed when the setting stroke and / or a setting force is reached. An absolutely tight closure of the control line is not absolutely necessary. This leads to an increase in pressure in the control line upon reaching the setting stroke and / or the setting force, whereby the pressure-controlled control valve is automatically switched to the second switching position. As a result, the pneumatic-hydraulic pressure booster is depressurized via the switching valve at the same time and a motor line, which leads to a pneumatic motor and drives it in Abdrillrichtung, connected to the pressure supply. Between the end of the setting process and the beginning of the Abdrillvorgangs so little time passes, the actuator can remain actuated all the time. Upon release of the actuator stops the setting process, which is continued on re-actuation of the actuator, wherein a twisting can only take place when the setting process is completed. A malfunction is therefore almost impossible. The setting process is thus performed not only very quickly with this procedure, but also very safe. A loosening before complete setting of the fastening nut is almost impossible.

The pressure is supplied in particular by a pressure channel which is formed in the housing. The pressure is always supplied with a net air pressure, the amount of which, however, is not sufficient to carry out the setting process. Therefore, the net air pressure in the pneumatic-hydraulic pressure booster is increasingly transmitted in a known manner to a hydraulic oil, which acts in the axial direction on the tension bolt.

Preferably, the first control surface of the control valve is larger than the second control surface. As a result, a safe switching of the control valve is ensured in the first switching position when the actuating element is no longer held and the first vent valve closes.

It is particularly preferred that between the motor line and the pressure supply, a bypass valve is arranged, which is in particular manually operable. With the help of this bypass valve, the motor line leading to the pneumatic motor, also outside the usual setting process with the pressure supply connected, so that the tension bolt can be rotated in Abdrillrichtung without previously a setting process is performed. This ensures that the blind rivet nut setting tool can be released from the blind rivet nut at any time.

Advantageously, a first relief valve and a second relief valve can be actuated simultaneously with the actuating element, wherein the first Relief valve of the control chamber and via the second discharge valve of the switching channel are pressure relieved, in particular between the second relief valve and the switching channel, a throttle point is arranged. By actuating the actuating element so the control chamber of the control valve is depressurized, so that there is also a discharge of the first control surface of the control valve. With a pressure increase in the control line, which leads to a pressure load of the second control surface of the control valve, therefore, a relatively small increase in pressure for a switching of the control valve is sufficient in the second switching position. When pressure relief of the switching channel, the switching valve is switched by the pressure of the pressure supply to the second position, so that the control line and the pneumatic-hydraulic pressure booster are connected via the switching valve with the pressure supply. By using two relief valves while a pure pressure actuation of the switching valve and the control valve is possible.

Preferably, the control line is closable with a valve device which is loaded in the opening direction by a spring and in the closing direction by an oil pressure of the pneumatic-hydraulic pressure booster. It is preferred that a bias of the spring is adjustable. This configuration ensures that upon reaching a desired oil pressure, which is a measure of the setting force achieved, the control line is closed by the valve device. This then leads to an increase in the pressure in the control line, whereby a pressure load of the
second control surface of the control valve, which thereby switches to the second switching position. By providing a spring whose bias is adjustable, the oil pressure at which the control line is closed by the valve means, can be specified. As a result, the maximum setting force with which the blind rivet nut setting device loads the blind nut can be set.

Preferably, alternatively or additionally, the control line can be closed by the draw bolt when the setting stroke is completed. This ensures that an increase in pressure in the control line and thus a switching of the control valve in the second switching position after passing through the setting stroke also takes place when the maximum setting force is not reached. It is also conceivable to design the blind rivet nut setting device from the outset to a specific setting stroke, which then represents the criterion for terminating the setting process.

It is particularly preferred that the setting stroke is adjustable, in particular in a range of 0 to 10 mm. This allows blind rivet nuts to be placed in components of different thicknesses using the blind rivet nut setting tool. By setting the setting stroke, the blind rivet setting tool is adapted to the respective material thickness, so that a safe setting of blind rivet nuts is possible even with different material thicknesses.

Preferably, a movable stop is provided for setting the setting stroke, wherein the control line runs along the stop and the tie bolt abuts the stop with completion of the setting stroke. This is a relatively easy way to close the control line, as the control line between the tie bolt and stop is performed and is closed when touching the tie bolt and stop. A complete seal is not required, the achievable pressure increase must only be sufficient for the control valve switches to the second switching position.

Preferably, the tension bolt has an increase in diameter, for example a circumferential flange, for abutment against the stop. This is a relatively easy way to realize a relatively large contact area between the tie bolt and the stop, so that a sufficient seal between the tie bolt and stop is achieved. At the same time, this training is relatively stable, so that the stop or the draw bolt are not deformed even at high tensile forces.

Preferably, the stop is arranged in a tubular sleeve which is screwed into the housing, wherein the tension bolt extends through the sleeve. The screw-in sleeve, the position of the stop within the housing can be relatively accurately determined and easily adjusted. This makes it easy to set the setting stroke. The stop extends doing so inside the sleeve radially inwards.

Preferably, a locking means is provided, with which a rotational movement of the sleeve is inhibited. By means of the locking means it is ensured that the sleeve is not moved unintentionally within the housing, which would lead to an adjustment of the set stroke setting. Since only relatively small rotational forces act on the sleeve during the normal setting process, complete latching of the sleeve by the latching means is not absolutely necessary. Inhibition is sufficient in many cases. Of course, a complete locking can be done.

Advantageously, the tension bolt protrudes through a mouthpiece out of the housing, which is arranged on the housing, in particular screwed to the housing. The mouthpiece is so interchangeable and can for example be adapted to different tension bolts. By removing the mouthpiece and a relatively simple replacement or installation of the tension bolt and the tubular sleeve is possible. The structure of the blind rivet nut setting device simplifies thereby.

Preferably, the tension bolt is designed in several parts, wherein in particular the threaded portion is exchangeable. By replacing the threaded area, the blind rivet nut setting tool can be adapted to different diameters of blind rivet nuts. It is possible, for example, the threaded area by commercial To form screws to DIN 912, which are connected via a corresponding hexagonal connection with the rest of the draw bolt. As a result, the blind rivet setting tool can be inexpensively adapted to different diameters of blind rivet nuts.

Preferably, the pneumatic motor is supplied with air in the setting stroke direction on the tension bolt, whereby the tension bolt is rotated in Aufdrillrichtung. As a result, a relatively simple and quick screwing of the threaded portion in a blind rivet nut is possible, which takes place without actuation of an additional actuating element. The Aufdrillen by pressure on the tension bolt from the outside, for example, in DE 3 215 468 C2 described.

Advantageously, the tension bolt is movable in the setting stroke direction by an oil piston. The oil piston is acted upon in the setting stroke by the pneumatic-hydraulic pressure booster with oil pressure. Contrary to the setting stroke, the oil piston can be loaded by the net air pressure, for example by connection to the pressure supply. As a result, in the absence of pressurization by the pneumatic-hydraulic pressure booster follows an automatic reset of the oil piston and thus a provision of the setting stroke.

It is particularly preferred that the tension bolt in Setzhubrichtung from the oil piston is entrained by positive engagement and counter to the Setzhubrichtung by the pressure of the pressure supply with a contact surface on the oil piston is pressable. In Setzhubrichtung, ie in the housing of Blindnietmuttern-setting tool, the tension bolt is thus pressed from the outside, where it is released from the oil piston. This movement of the pull bolt can be used to switch a valve, so that the Aufdrillvorgang is performed automatically. By the net air pressure, however, it is ensured on release of the external load on the tie bolt that the system of the tie bolt rests again on the oil piston. If now the oil piston is acted upon by the pneumatic-hydraulic pressure booster with an oil pressure, the oil piston moves in Setzhubrichtung, ie in the housing, and takes the tie bolt by positive engagement. The positive connection is created by the fact that the tension bolt rests with its contact surface on the oil piston. In this case, relatively high forces are transferable.

Advantageously, the control valve has a tubular valve element, wherein the pressure supply to the control chamber through the valve element takes place and the throttle is arranged in the interior of the valve element. Such a design makes a very space-saving design possible. The valve element assumes a double function. On the one hand, it serves to supply pressure to the control chamber and absorbs the throttle, on the other hand, it takes over the usual switching functions of a control valve, so in each case the corresponding connections per switching position available.

In a preferred embodiment, the control line is replaced by a channel through which a pressure is supplied to a third control surface of the control valve, which acts in the same direction with the second control surface. By pressure on the third control surface, the control valve is thus also moved in the direction of the second switching position. This increases the safety with which the control valve switches from the first switching position to the second switching position. Already at a relatively low pressure increase in the control line or even if there is still a residual pressure in the control chamber, the control valve is switched to the second switching position and thus an end of the setting process.

Preferably, the switching channel is connected in parallel to the control valve via a throttle with the pressure supply. This ensures that, even with prolonged non-operation of the blind rivet nut setting device sufficient pressure prevails in the switching channel, which holds the switching valve in the first position. The switching valve can then only switch from the first position to the second position when the actuating element is actuated. This always ensures a defined position of the switching valve.

Advantageously, the throttle is arranged in an inner space of a tubular valve element of the switching valve, wherein the throttle has a smaller opening cross-section than the throttle point. The opening cross section of this throttle should also be smaller than the opening cross sections of the other throttles.

With this design, the space that is required anyway for the movement of the valve element, for the formation of the throttle and the throttled connection between the pressure supply and the switching channel can be used. As a result, the space requirement is kept very low.

Fig. 1

einen Querschnitt durch ein Blindnietmuttern-Setzgerät mit aufgedrillter Blindnietmutter vor Beginn des Setzhubs,

Fig. 2

das Blindnietmuttern-Setzgerät nach Fig. 1 im Moment des Erreichens des eingestellten Setzhubs,

Fig. 3

das Blindnietmuttern-Setzgerät nach den Fig. 1 und 2 kurz nach Erreichen des eingestellten Setzhubs und

Fig. 4

ein Blindnietmuttern-Setzgerät entsprechend Fig. 1 bei Erreichen der maximalen Setzkraft.

The invention will be described below with reference to a preferred embodiment in conjunction with the drawings. Herein show:

Fig. 1

a cross section through a blind rivet nut setting tool with a riveted blind rivet nut before the beginning of the set stroke,

Fig. 2

the blind rivet nut setting tool after Fig. 1 at the moment of reaching the set stroke,

Fig. 3

the blind rivet nut setting tool after the Fig. 1 and 2 shortly after reaching the set stroke and

Fig. 4

a blind rivet setting device accordingly Fig. 1 when reaching the maximum setting force.

In Fig. 1 schematically a blind rivet nut setting tool 1 is shown in sectional view. The Blindnietmuttern-setting tool 1 has a housing 2 in which a tie bolt 3 axially displaceable and rotatable is stored. Axial means in the longitudinal direction of the tie bolt. 3

The tension bolt 3 passes out of the housing 2 through a mouthpiece 4, which is screwed into the housing 2. At one end, which protrudes from the housing 2, the draw bolt 3 has a threaded portion 5, wherein in the illustrated situation, a blind rivet nut 6 is already twisted onto the threaded portion 5 of the draw bolt 3.

The Aufdrillen can for example take place in that the blind rivet nut 6 is pressed in the axial direction against the tie bolt 3, so that it is slightly displaced axially, thereby a non-illustrated valve device is actuated such that a not shown pneumatic motor is supplied with pressure, so that this sets the tension bolt 3 with its threaded portion 5 in the winding direction in rotation. The blind rivet nut 6 is then automatically wound on, so to speak, until it rests with a setting head 7 on the mouthpiece 4.

To set the blind rivet nut 6, this must be guided through an opening in a workpiece and then deformed, wherein the deformation takes place by an axial pulling movement through the tension bolt 3. For this purpose, the blind rivet setting tool 1 has a pneumatic-hydraulic pressure booster 8, which has a pneumatic cylinder 9 and a hydraulic cylinder 10. A shaft 11 of a pneumatic piston 12 forms a piston of the hydraulic cylinder 10. Since the surface of a pneumatic piston 12 is much larger than that of the shaft or the hydraulic piston 11, there is a large power gain. The hydraulic cylinder 10 is connected via an oil pressure line 13 with an oil pressure chamber 14 in communication, which forms a piston chamber for an oil piston 15. The oil pressure piston 15 is moved by the pressure in the oil pressure passage 13, which is generated by the pressure booster 8, in the setting stroke direction (in FIG Fig. 1 to the right) is pressed when the pneumatic cylinder 9 is connected to a pressure supply 16, so that the pneumatic piston 12 is acted upon by a net air pressure of the pressure supply 16.

On a side facing away from the oil pressure chamber 14 side of the oil pressure piston 15 is acted upon by the net air pressure of the pressure supply, so that is pressed in non-actuation of the pressure booster 8 of the oil pressure piston in the illustrated rest position.

In the in Fig. 1 shown starting position before the beginning of a setting operation, the pneumatic cylinder 9 of the pressure booster 8 is connected via a pressure-controlled switching valve 17 with an outlet channel 18 which is open to the environment. Thus, the pneumatic cylinder 9 is depressurized.

The switching valve 17 is in a first position, in which not only the pneumatic cylinder 9 but also a control line 19 is connected via the switching valve 17 to the outlet channel 18. For this one has tubular valve element 20 of the switching valve 17 an annular space 21.

The switching valve 17 is loaded in the direction of a second switching position by the net air pressure of the pressure supply 16, which acts on a first control surface 22. On a second control surface 23, which is larger than the first control surface 22, in the initial state is also the net air pressure, which is included on the one hand due to previous setting operations in a switching channel 24, but also by a throttle 25 formed in the interior of the tubular valve member 20 is and the pressure supply 16 connects to the switching channel 24, is constructed.

By actuating an actuating element 26, a first venting valve 27 and a second venting valve 28 are simultaneously opened. When the second venting valve 28 is opened, the switching channel 24 is relieved of pressure via a throttle point 29, so that a greater pressure acts on the first control surface 22 of the switching valve 17 than on the second control surface 23. As a result, switching of the switching valve 17 takes place upon actuation of the actuating element. The switching valve 17 thus switches to the second position, the in Fig. 2 is shown.

In the second position of the switching valve 17, the pneumatic cylinder 9 of the pressure booster 8 is connected via the switching valve 17 to the pressure supply 16. At the same time, the control line 19 with the pressure supply 16, wherein between the switching valve 17 and the control line 19, a throttle 30 is arranged. The control line 19 is guided along a valve device 31 and along the tie bolt 3 to the outside, wherein in the mouthpiece 4 vent openings 32 are provided.

In the in Fig. 1 illustrated initial situation, the control line 19 is unlocked, so that initially no pressure build-up in the control line 19 takes place even when connecting the control line 19 to the pressure supply 16.

The pressure in the control line 19 acts on a second control surface 36 of a control valve 37. On a first control surface 38 of the control valve 37, which is greater than the second control surface 36, a pressure acts in a control chamber 39. The control chamber 39 is via a throttle 40th always connected to the pressure supply 16 and can be relieved of pressure via the first relief valve 27. Upon actuation of the actuating element 26, the control chamber 39 is depressurized.

In the in Fig. 1 shown initial position, the first relief valve 27 is closed, so that in the control chamber 39, the net air pressure prevails and the control line 19 is depressurized, so that the control valve 37 is in the first switching position shown. In the first switching position, the control valve 37 prevents communication between a motor line 41 and the pressure supply 16.

For manual connection, a bypass valve 49 is provided, via which the motor line 41 can be connected to the pressure supply 16 independently of the position of the other valves. The bypass valve 49 is for simplicity only in Fig. 1 but also provided in the other examples.

The setting process for setting a blind rivet nut 6 by means of the blind rivet nut setting device 1 now proceeds as follows. Starting from the in Fig. 1 illustrated starting situation in which the blind rivet nut 6 is screwed or threaded onto the threaded portion 5 of the tension bolt 3 and inserted into a workpiece opening, actuation of the actuating element 26. This takes place via the first relief valve 27, a pressure relief of the control chamber 39 and through simultaneous opening of the second relief valve 28, a pressure relief of the switching channel 24. By the pressure relief of the switching channel 24, the switching valve 17 switches from the in Fig. 1 shown first position in the in Fig. 2 shown second position. In the second position of the switching valve 17, the hydraulic pressure booster 8 is connected to the pressure supply, so that a force is exerted on the pneumatic piston 9, which is transmitted via the hydraulic piston 11, the oil pressure passage 13 and the oil pressure chamber 14 to an oil piston 15. The oil piston 15 is thereby moved axially and causes a pulling movement on the tension bolt 3. This leads to a deformation of the blind rivet nut 6, as in Fig. 2 is shown.

The oil pressure in the oil pressure line 13 acts in the closing direction on a valve element 33 of the valve device 31, wherein the valve element 33 is acted upon in the opening direction by a spring 34. A bias of the spring 34 can be changed by screwing in an abutment 35.

The axial movement of the pull bolt 3 takes place until a set stroke or a desired setting force is reached. The setting of the setting stroke, ie the distance by which the tension bolt 3 can be displaced, is effected by means of a movable stop 42 which is arranged in a tubular sleeve 43 which is screwed into the housing 2. Depending on how far the tubular sleeve 43 is screwed into the housing 2, the position of the stop 42 is changed and thus set the setting stroke. The tension bolt 3 has an increase in diameter 44, with which the tension bolt 3 rests against the stop 42 when the set stroke is reached.

Since the control line 19 is guided outwardly between the stop 42 and the draw bolt 3, the control line 19 is closed when the diameter enlargement 43 of the draw bolt 3 against the stop 42 is applied. The control line 19 is connected via the switching valve 17 and the throttle 30 to the pressure supply 16, so that upon closure of the control line 19, a pressure in the control line 19 increases until finally the net air pressure in the control line 19 prevails. The beginning the pressure rise in the control line 19 by conditioning the tension bolt 3 on the stop 42 on reaching the set stroke Setz is in Fig. 2 shown. However, the pressure build-up in the control line 19 has just begun and is not enough to press the control valve 37 in the second switching position.

In Fig. 3 the situation at the completion of the setting operation and the beginning of the Abdrillvorgangs is shown, in which the motor line 41 is connected via the control valve 37 to the pressure supply 16, so that an unillustrated pneumatic motor rotates the tension bolt in Abdrillrichtung.

The control valve 37 has been switched to the second switching position by the pressure in the control line 19, which acts on the second control surface 36. On the one hand, the switching channel 24 is connected via the control valve 37 to the pressure supply 16, so that the switching valve 17 switches back to the first position, in which the pneumatic cylinder 9 with the outlet channel 18 is connected and thus relieved of pressure. The venting of the switching channel 24 via the second vent valve 28 is due to the throttle point 29 is not sufficient to prevent pressure build-up in the switching channel 24 by the pressure supply 16. The switching valve 17 thus also switches back to the first position when the actuator 26 remains actuated.

Immediately after the control valve 37 and its tubular valve element 45 is switched to the second switching position, that is, the switching valve 17 is switched back to the first position and the pneumatic-hydraulic pressure booster 8 relieved, so that the tension bolt 3 is relieved. At the same time begins by the connection of the motor line 41 to the pressure supply 16 of the Abdrillvorgang. Between the end of the set stroke and the beginning of the Abdrillvorgangs thus arises only a barely perceptible break. The blind rivet setting tool 1 thus works very fast.

As soon as the actuating element 26 is released after completion of the Abdrillvorgangs, close the vent valves 27, 28, whereby in the control chamber 39 of the control valve 37, the net air pressure is built up, since the control chamber 39 is connected via the throttle 40 to the pressure supply 16. As a result, the control valve 37 switches back to its first switching position. The control line 19 is already connected via the switching valve 17 to the outlet channel 18 at this time and accordingly depressurized. The blind rivet nut setting device 1 is then again in the in Fig. 1 shown state.

In order to achieve a safe and faster switching of the control valve 37 from the first switching position to the second switching position already at a low pressure buildup in the control line 19, goes from the control line 19 from a channel 46, which leads to a third Control surface 47 of the control valve 37 leads, which acts in the same direction with the second control surface 36.

In the Fig. 2 and 3 shows how the setting process is terminated by reaching the desired setting stroke. The setting stroke has been adjusted by the corresponding positioning of the stop 42. The valve device 31 has not entered into function. Rather, the spring 34 was biased by means of the adjustable abutment 35 maximum, so that even a large increase in the oil pressure in the oil pressure line 13 can not lead to a closure of the valve device 31.

In Fig. 4 is now the Blindnietmuttern-setting tool 1 set such that it does not stop the setting process when the desired setting stroke, but upon reaching the desired setting force. The tubular sleeve 43 has been screwed completely into the housing 2, so that the stop 42 is in a position in which it is spaced as far as possible from the diameter enlargement 44 of the tension bolt 3. So it is set the maximum setting stroke, which is for example 10 mm. The setting stroke is variable depending on the length of the blind rivet nut and the material thickness between 0 and 10 mm.

Starting from the in Fig. 1 shown situation, the blind rivet nut 6 has been inserted into an opening of a member 48 and the actuator 26 is actuated. In the manner described above is then the pulling process started, with in Fig. 3 it is now shown that the desired setting force has been achieved. A measure of the setting force is the oil pressure in the oil pressure line 13, which acts in the closing direction on the valve element 33 of the valve device 31. Thereby, the valve element 33 of the in the Fig. 1 to 3 shown position in the Fig. 4 shifted position shown, wherein the control line 19 is closed by the valve element 33 and the valve means 31. This in turn results in a pressure increase in the control line 19, which is still connected via the switching valve 17 and the throttle point 30 to the pressure supply 16 at this time. This increase in pressure results in the switching of the control valve 37 in the second switching position, which causes a switching of the switching valve 17 back to a first position. While the pneumatic motor or the motor line 41 are connected to the pressure supply 16 via the control valve 37, a pressure relief of the pressure booster 18 and thus a relief of the tension bolt 3 takes place via the switching valve 17.

The Abdrillvorgang, so unscrewing the tension bolt 3 from the blind rivet nut 6 is thus carried out immediately after reaching the desired setting force.

The Blindnietmuttern-setting tool 1 according to the invention thus works very fast. In this case, the setting process can be interrupted at any time during the setting process by releasing the actuating element 26, wherein the setting process is continued upon renewed actuation of the actuating element. If the setting process so For example, was carried out incorrectly by releasing the actuator too early, the Abdrillvorgang is not started. So you always have a control over whether the set stroke or the set setting force, depending on the selected mode, has actually been achieved.

By taking advantage of the net air pressure or by connecting the motor line to the pressure supply for twisting, the pneumatic motor can be operated with a high torque, wherein the Abdrillvorgang runs as long as the actuator is held. If too early release of the actuator occurs, e.g. via an additional bypass valve, which is not shown in the drawings, the pressure supply, bypassing the control valve are passed directly into the motor line, so that even then another Abdrillen is possible.

It is also conceivable, for example, to manually rotate the air motor and unscrew the mandrel so from the blind rivet nut. However, this is usually time consuming.

In an adjustment of the stop or the position of the tubular sleeve within the housing 2, there is no change in the length of the mandrel. The adjustment of the stop can be done without tools, with a scale can be provided so that the set stroke can be read from the outside.

By using the net air pressure of the pressure supply to return the oil piston can be dispensed with an additional return element, such as a spring. This simplifies the overall structure.

Claims (10)

1. Blind rivet nut setting device having a housing in which a tension bolt is arranged rotatably and axially movable, which protrudes at least with a threaded portion out of the housing, and with a pneumatic-hydraulic pressure booster comprising a pneumatic cylinder and a hydraulic cylinder, wherein a pressure controlled switching valve is provided connecting in a first position the pneumatic cylinder to an outlet channel and in a second position the pneumatic cylinder to a pressure supply, characterized in that the switching valve (17) switches upon actuation of an actuating element (26) into the second position, wherein in the second position a control line (19) having a passage to the environment is connected to the pressure supply (16) via a throttle (30) and the switching valve (17), wherein the control line (19) is closed upon reaching a setting stroke and/or a setting force, wherein a pressure in a control chamber (39) of a pressure control control valve (37), which is connected via a throttle (40) to the pressure supply (16), acts on a first control surface (38) of the control valve (37) in the direction of a first switching position and a pressure in the control line (19) acts on a second control surface (36) of the control valve (37) in the direction of a second switching position, wherein the control chamber (39) is depressurized upon actuation of the actuating element (26), wherein in the second switching position a motor line (41) of a pneumatic motor for unscrewing of a blind rivet nut (6) from the tension bolt (3) and a switching channel (24) of the switching valve (17) are connected to the pressure supply (16), whereby the switching valve (17) switches to the first position,
2. Blind rivet nut setting device according to claim 1, characterized in that together with the actuation element (26) at the same time a first relief valve (27) and a second relief valve (28) can be actuated, wherein via the first relief valve (27) the control chamber (39) and via the second relief valve (28) the switching channel (24) can be pressure relieved, wherein in particular between the second relief valve (28) and the switching channel (24) a throttle point (29) is arranged.
3. Blind rivet nut setting device according to any of claims 1 or 2, characterized in that the control line (19) is closable with a valve device (31), which is loaded in opening direction by a spring (34) and in closing direction by an oil pressure of the pneumatic-hydraulic booster (8).
4. Blind rivet nut setting device according to any of claims 1 to 3, characterized in that the control line (19) is closable by the tension bolt (3) when the setting stroke is completed.
5. Blind rivet nut setting device according to any of claims 1 to 4, characterized in that for the setting of the setting stroke a movable stop (42) is provided, wherein the control line (19) runs along the stop (42) and the tension bolt (3) rests against the stop (42) upon completion of the setting stroke.
6. Blind rivet nut setting device according to claim 5, characterized in that the stop (42) is arranged in a tubular sleeve (43), which can be screwed into the housing (2), wherein the tension bolt (3) extends through the sleeve (43).
7. Blind rivet nut setting device according to claim (6), characterized in that a lagging means is provided with which a rotational movement of the sleeve can be inhibited.
8. Blind rivet nut setting device according to any of claims 1 to 7, characterized in that the control valve (37) comprises a tubular valve element (45), wherein the pressure supply (16) to the control chamber (39) takes place through the valve element (45) and the throttle (40) is arranged in the interior of the valve element (45).
9. Blind rivet nut setting device according to any of claims 1 to 8, characterized in that from the control line (19) a channel (46) branches off through which a power supply to a third control surface (47) of the control valve (37) takes place acting in the same direction with the second control face (36).
10. Blind rivet nut setting device according to any of claims 1 to 9, characterized in that the switching channel (24) is connected to the pressure supply (16) via a throttle (25).

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