EP1138444B1 - Pressurised fluid driven pliers - Google Patents

Abstract

The pliers has a control region with a pressure medium connection (81) and valve (71), at least one working piston (36) controlled by the valve, jaws halves (19) pivoted by a thrust element, a valve pin actuated by a trigger transversely to the piston's direction of motion and a force sensor (26) in the force transfer path between the working piston and the jaws halves for measuring as force dependent on the closing force of the jaws halves. Independent claims are also included for the following: a construction kit system with pressure medium pliers.

Description

The invention relates to a pressure medium pliers for clamping rings, clamps, Bolts, cable lugs and the like. The pressure medium pliers are basically for any Suitable objects that are pressed.

Pressure pliers are used in particular to permanently deform clamping rings, so that one part clamps to another, e.g. a hose on a nozzle. They are used, for example, in automobile production.

From DE 195 19 543 C2 a pressure medium pliers is known which have a pressure medium connection and an associated pressure medium valve, several separate, drive piston controlled by the pressure medium valve, one by the drive piston drivable feed link and swiveling pliers halves, at the inner lever ends of the feed member engages to this pivot, has. These pressure medium pliers are intended to achieve the required Ensure the closing gap of the pliers halves under full force and favor an independent influence of the closing forces on the working pressure. For this purpose, the pressure medium valve is displaceable in the transverse direction of the piston movement guided and actuated by a trigger valve pin, which in a In the rest position, the connection of the drive piston to the pressure medium connection locks and connects this with a lower pressure level and in one through Actuation of the trigger reachable working position the connection of the drive piston locks with the lower pressure level and this with the pressure medium connection combines. In addition, the drive piston is in a direction of movement extending guide a shift rod held movably by a spring is biased to the valve pin, the shift rod having an external step as a driver and the drive piston has a drilled through the shift rod Shaft with an inner step assigned to the outer step as a stop to take with you the shift rod in the last section of its movement to close the Pliers insert halves. The valve pin has a locking seat in the shift rod under the action of the spring when the valve pin moves from the rest to the Working position engages and the shift rod when it is carried by the Drive piston releases. As a result, the piston is always forced from an initial position moved into an end position in which the pliers have sufficient Closing time reached the required closing gap.

However, incorrect assembly can also occur with these pliers, for example if the operator places the pliers incorrectly on the clamping ring or pressure fluctuations occur in the pressure medium network, which is mostly a compressed air network.

From DE 198 19 716 C1 according to the preamble of claim 1, a pressure medium pliers is known, which are for assembly of clamping rings and the like with further improved quality and for a reduction the effort for the follow-up inspection of the clamping ring assembly one in the frictional connection arranged between the drive piston and the pliers halves Force sensor for measuring a force dependent on the closing force of the pliers halves Has strength. The force sensor is integrated in the feed link. moreover is the force sensor with an evaluation device for controlling a display or The pliers are switched off if the closing force is not met and / or a documentation device for documenting the closing force connected. However, this pressure medium pliers is not in all cases ensures that the full closing force is reached at the required closing gap becomes.

Proceeding from this, the object of the invention is a pressure medium pliers to create an assembly of clamping rings and the like. With even more improved Quality enables the effort for the post-inspection of the clamping ring assembly further reduce.

The task is performed by a pressure medium pliers with the features of the claim 1 solved. Advantageous configurations of the pressure medium pliers are in the subclaims specified.

The pressure medium pliers according to the invention for clamping rings and the like comprises a control area with a pressure medium connection and an associated Pressure medium valve, at least one drive piston controlled by the pressure medium valve and a work area with a drivable by the drive piston Feed link and pivoted pliers halves, on the inner Lever ends engages the feed member to pivot them. The pressure fluid valve has a slidably guided in the transverse direction of the piston movement and actuated by a trigger valve pin, the connection in a rest position locks the drive piston with the pressure medium connection and this with connects a lower pressure level and which in a by pressing the Trigger reachable working position the connection of the drive piston with the locks lower pressure level and connects it to the pressure medium connection. A shift rod is movable in a guide in the direction of the drive piston held, which is biased by a spring to the valve pin, the shift rod a driver and a drive piston a stop associated with this Take the shift rod in the last section of its movement to close the pliers insert halves. Furthermore, the valve pin has a locking seat in which the Switch rod under the action of the spring when the valve pin moves from the at rest the working position engages and which the shift rod takes when you take it with you releases the drive piston. In addition, is in the frictional connection between the drive piston and the forceps insert halves a force sensor for measuring one of the closing force of the forceps insert halves dependent force. The Force sensor is secured against rotation with respect to the displacement axis of the feed element guided.

The pressure medium pliers according to the invention thus have a positive control that enforces that after actuation of the pressure medium valve the piston with Pressure medium must be applied until the required closing gap is set and the piston is not depressurized beforehand. This forced control is the first time combined with a force measurement on the feed element, which determines the closing force achieved by the pliers insert halves. This will ensuring that the closing gap is reached, even if - surprisingly can be determined in individual cases - even before the closing gap is reached a force corresponding to the required closing force is measured, what can be based, for example, on the flow behavior of the materials. Furthermore may be due to a measurement of an impermissible force before the closing gap is reached the work process is stopped prematurely, e.g. for damage to avoid tools or workpieces. On the other hand, this favors Pressure fluid pliers to detect incorrect assembly if the specified one is reached Closing gap impermissible force values can be determined, in particular based on tolerances of the components involved or damage to them can. Through the combination of closing gap control and force measurement thus the assembly of clamping rings and the like. With significantly further improved Quality enables and the effort for the follow-up control is further reduced. The anti-rotation device of the force sensor prevents a lead out lead is twisted or damaged. This will make the Functionality of the clamping force measurement ensured and the quality of the Clamping ring assembly further improved.

According to an embodiment of the pressure medium pliers according to the invention that is Press the shift rod against the valve pin by means of a spring and take it with you the switch rod in the end area of the feed movement is particularly easy to install solved. For this purpose, the shift rod is connected to a partition on a spring supported between pressure medium valve and drive piston. For taking away the shift rod is the adjacent drive piston T-shaped and has this drive piston the inner step in its shaft, which is located on the following drive piston supported. The devices for engaging and taking the shift rod are therefore limited to the intermediate wall and the adjacent drive piston. Other drive pistons do not and cannot accommodate these construction elements independently manufactured, assembled and in the required clamping force necessary number can be staggered in a row. Only the length of the case is to be adapted to the number of pistons. This configuration will So a modular adjustment of the pressure medium pliers to different force requirements favored.

The guide for the shift rod can be arranged on the intermediate wall. The Adjacent drive pistons can be on one and the valve pin on the other Side of this partition are also a stop for the drive piston can form.

According to a preferred development, the shift rod already snaps into the locking seat before the valve pin reaches its working position. This will create a Intermediate position between rest and working position allows in the pliers halves cannot be swiveled despite trigger actuation.

The valve pin can be used to stop the pliers from closing prematurely a trigger pin can be held by pressing a vent button Shift rod is displaceable and pushes it out of the locking seat. Then he can Return the valve pin to its rest position, in which the pliers open again.

The valve pin can preferably be provided with an elongated groove into which an alignment pin engages the valve pin and thus the locking seat or release pin aligns correctly.

A plurality of drive pistons staggered one behind the other are preferred for pressure transmission available that are T-shaped and have a pierced shaft. At a T-shaped piston with a pierced and directed towards the feed member The shift rod can be shank with its driver designed as an external step protrude into the hole in which the drive piston stops as an internal step can be trained.

The pliers insert halves can be used to set the minimum closing gap be held on a sleeve-shaped pliers head, which in turn by means of a Adjusting ring is held on the housing of the pressure fluid pliers. Between pliers head and adjusting ring, an adjusting thread is formed, which is an axial adjustment of the Pliers head to the housing allows. By adjusting the pliers head the position of the pliers halves changed relative to the feed member, whereby the minimum closing gap is changed. The collar can be an external stage have that of the flange of a locking ring for fixing the adjusting ring to the housing is spread. After loosening the locking ring, the adjusting ring can be turned, whereby the pliers head can be screwed into the desired axial position around the Adjust the closing gap.

Preferably, a fixable tab can between the pliers head and collar Fixing pliers head and collar in different screw positions of the Collar. The tab can be fixed with a section detachably screwed to the circumference of the pliers head and with another Section in one of several circumferential grooves of the collar be used. The tab can also be engaged by engaging in a groove Screw be releasably fixed to the collar, which screw is an elongated hole Straps through to be effective in different screw positions. To Removing the tab from the pliers head is the pliers head in the top described manner rotatable by turning the collar to the Adjust the closing gap. After making the setting, pliers head and The collar can be fixed again using the tab.

The pliers head and the collar can preferably have an index and markings to identify their different screw positions. For example can the collar in four different angular positions with respect to Pliers head can be screwed and / or the pliers head and the collar an index and wear four different marks.

Another setting can be realized in that the pressure medium valve is housed in a valve housing on which the pliers insert halves opposite end of the housing with this via another adjusting thread connected is. By adjusting the valve housing it is possible to influence in which position of the drive piston released the locking of the valve pin and the minimum Closing gap is reached. This is a length compensation, for example, during assembly possible for the shift rod. However, this setting option will preferably not by the user, but for adjustment during final assembly to be used. The further adjusting thread with a locking ring is therefore preferred provided for clamping the valve housing and housing. The Circlip can in turn by means of a special screw fixation on Housing can be fixed.

The force measurement is based on the knowledge that the closing force of the pliers insert halves, i.e. from the halves of the pliers to a clamping ring or Applied force, of which in the power flow between the drive piston and the Forceps occurring force is dependent. In particular, it was found that the force in the feed member, which preferably with a tapered Front end, which can be wedge-shaped or parabolic, against the inner Lever ends of the pliers halves presses and the other ends with a piston can be screwed, has an almost ideal linear dependence on the closing force. The closing force can therefore be determined very precisely via the force sensor. Also annoying the arrangement in the power flow between the drive piston and pliers halves not assembly, as they are not in the working area of the pliers halves intervenes. On the other hand, it does not interfere with the pressure build-up in the area of the drive pistons. In addition, this will also be different Pressure medium pliers, in which the force measurement is designed to match can be and which is only staggered by the number in a row Differentiate pistons, which is selected depending on the desired clamping force.

The force measured by the force sensor is different within the scope of the invention Way usable. So it can be used by an evaluation device for control a display, for example an optical and / or acoustic display and / or to switch off the pressure medium pliers, each in the event of non-compliance Specification for the closing force can be used. When specifying the closing force can be a minimum force that must be achieved. It can but it is also a maximum force or a minimum force and a maximum force that must be observed at the same time. If, for example, the tong seeding halves only to an edge area of a clamping zone of the clamping ring act, only a fraction of the closing force is achieved, which when correctly applied the complete clamping zone would be built. If the pliers halves on the other hand, are placed on a wrong zone of the clamping ring, the Excessive closing force occurs when the clamping zone is more difficult to deform. The evaluation device can recognize and display this and / or the pressure medium pliers switch off prematurely so that the operator can immediately recognize the error and can correct.

In addition or instead, the evaluation device can also control the pressure of the Control the drive of the drive piston causing pressure medium so that a specification for the closing force is observed. For this, the evaluation device can Operate pressure control valve, which can be assigned to the pressure medium connection and at the same time can be the pressure medium valve, which controls the movement of the drive piston controls.

Additionally or instead, the measured force can be obtained from a documentation device be documented, e.g. from a plotter and / or from a PC with an electronic memory. This is about error analysis and error control also created the possibility of proof of quality.

The force sensor is preferably integrated in the feed member. For example he be plate-shaped. Furthermore, it can be on the side facing the piston of the feed member. The force sensor is preferably located between two sections of the feed link. It can be on a center hole, for example in the case of an annular disc, be guided on a bolt, which extends in the direction of force flow and is anchored in the feed member, in particular by screwing in. There is both a force measurement in the main conclusion as well as in the shunt, in the first case the total power flow via the sensor and in the second case the power flow only partially via the sensor he follows. In both cases, the sensor can be biased with a force. A Arrangement in the shunt is given in particular when the force sensor on a Center hole on a bolt between two sections of the feed link is held, the bolt with its two ends in the is screwed to a certain preload on the two sections Exercise force sensor. By biasing the sensor, the zero point of the Force measurement defined.

The force sensor can be a strain gauge (DMS) sensor, a piezo sensor or any other suitable force sensor. In particular force sensors on strain gauge or piezo base is available in plate form, in particular in the form of an annular disc. Especially in this version they are suitable for integration into the feed link. In particular Strain gauge sensors can also be attached to the jacket of a feed element his.

A flexible connecting cable of the force sensor is preferably provided in the direction of movement of the feed member extending slot in the sleeve-shaped Pliers head or in a housing section receiving the feed member led out. The slot extends in particular over the entire Range of movement of the force sensor in the feed member. The led out Part of the connection cable can also be fixed to the housing. Here, the Slit to be covered from the outside by a hood fixed to the housing, which has a cavity has, in which the connecting cable when moving the feed member can deform. The connecting cable of the force sensor can also be used with a Pressure hose connected to be guided away from the pressure pliers.

Stands as an anti-rotation device for the force sensor at least one guide pin from the feed member and engages in a slot the sleeve-shaped pliers head or in a receiving member Housing section into it. The slot is the same slot through which the flexible cable is led out. Then at least a guide pin next to the flexible connection cable in the slot.

The pressure medium pliers can be a pressure sensor for monitoring the pressure of the Have pressure medium. This sends the measured signal to an evaluation device to output a display or to switch off the pressure medium pliers at Failure to meet a requirement for the pressure to a control device for the Printing and / or to a documentation device for documenting the Pressure further.

Above all, the specification relates to a minimum pressure required to achieve the required pressure Closing force is required. But it can also affect a maximum pressure, to avoid impermissibly high clamping forces, for example too can lead to destruction of the components to be connected, not exceeded may be. The specification can also have a minimum pressure and a maximum pressure include. The evaluation device gives the worker optical or acoustic Display or by switching off the pressure medium pliers a hint that the for the assembly required pressure is not present, which prevents incorrect assembly become. The latter can also be avoided in that the Pressure sensor controls the pressure of the pressure medium via a control device. So the pressure sensor can cause a pressure control unit to adjust the feed pressure for the To increase or decrease pressure medium pliers. Finally, it is also possible To document printing using a documentation device to be able to use a Failure analysis and avoidance of errors also a quality document for the clamping ring assembly to obtain.

In addition, gauges for adjusting the closing gap can be used for the pressure medium pliers be available and / or a table for the dependency of the closing gap setting of the workpiece (clamping ring or the like) and the pressure in one Pressure fluid network.

Fig. 1

die Druckmittelzange mit abgesprengtem Auslösehebel bei Betätigung mit den Antriebskolben in der Ausgangsstellung im Längsschnitt;

Fig. 2

Arbeitsbereich derselben Druckmittelzange nach Auslöserbetätigung mit dem vordersten Antriebskolben in der Endstellung im Längsschnitt;

Fig. 3

derselbe Abschnitt der Druckmittelzange ohne Seitenteile und Zangeneinsatzhälften in einem bezüglich Fig. 2 um 90° gedrehten Teilschnitt;

Fig. 4

dieselbe Druckmittelzange vor Auslöserbetätigung in einer Seitenansicht;

Fig. 5

dieselbe Druckmittelzange von der gegenüberliegenden Seite gesehen;

Fig. 6

die Druckmittelzange nach in einem Schnitt entlang der Linie VI-VI der Fig. 5;

Fig. 7

dieselbe Druckmittelzange in der Draufsicht.

The invention is explained in the following drawings of an embodiment of a pressure medium pliers for manual operation. The drawings show:

Fig. 1

the pressure medium pliers with a detached release lever when operated with the drive piston in the starting position in longitudinal section;

Fig. 2

Working area of the same pressure medium pliers after trigger actuation with the foremost drive piston in the end position in longitudinal section;

Fig. 3

the same section of the pressure medium pliers without side parts and pliers insert halves in a partial section rotated by 90 ° with respect to FIG. 2;

Fig. 4

the same pressure medium pliers before trigger actuation in a side view;

Fig. 5

the same pressure medium pliers seen from the opposite side;

Fig. 6

the pressure medium pliers in a section along the line VI-VI of Fig. 5;

Fig. 7

the same pressure medium pliers in plan view.

The pressure medium pliers essentially have four functional areas: The working area 1, the drive area 2, the measuring area 3 and the control area 4.

The work area 1 has a substantially sleeve-shaped pliers head 5 which is fixed via an adjusting ring 6 to one end of a cylindrical housing 7. A flange 8 of the collar 6 is overlapped by a locking ring 9 and on the housing 7 screwed tight. There is an adjusting thread between the pliers head 5 and the collar 6 10 trained. In a groove 11 on the circumference of the pliers head 5 and in one of four is evenly distributed over the circumference of the collar 6 grooves 12 a tab 13 is used, which is fixed by means of a screw 14 in the groove 11. As a result, pliers head 5 and collar 6 in the screw position shown connected with each other.

On both sides of the protruding sections 15 of the pliers head 5 are by means of Bolt 16 side panels 17 attached.

The side parts 15 are penetrated by two insert bolts 18 directed transversely thereto, a pliers insert half 19 pivotally mounted on each insert pin 18 is. The two pliers insert tips 20 at the front end of the pliers insert halves 19 can be pivoted together except for a closing gap (see FIG. 2). there the pliers insert tips 20 exert a closing force on one in between with one Clamping zone arranged from the clamping ring.

The pliers insert halves carry 19 rollers 21 at their inner lever ends The pliers insert tips 20 are at rest by at least one on the pliers insert halves 19 attacking spreading spring 22 pivoted apart until the Rollers 21 touch each other. Plier insert halves 19 can also be mounted that have a different geometry in front of objects other than To carry out compression rings.

The drive region 2 has an axial bore in the front of the housing 7 23 of the pliers head 5 protruding feed member 24 with a circular cross section on. This has a front section 24 'and a rear section 24 " front section 24 'has a wedge-shaped section 24' 'which is entirely from a large wedge angle and behind it a smaller wedge angle. The Both sections 24 ', 24 "are by an axially directed screw 25th connected with each other.

The screw bolt 25 sits centrally between the two sections 24 ', 24 " of the feed member 24, an annular disk-shaped force sensor 26 it is a strain gauge or a piezo sensor. On both sides of the Force sensor 26 circular washers 27 sit on the bolt 25. The Bolt 25 is tightened to a defined torque, so that the sections 24 ', 24 "of the feed member 24 via the annular disks 27 a defined Apply biasing force to the force sensor 26, which is typically 10% of the is 26 measurable maximum force with the force sensor.

The circumference of the force sensor 26 is radial and seals against the sensor housing a connection cable 28 led out through a slot 29 of the pliers head 5 is led to the outside. The slot 29 extends over the entire Displacement range of the force sensor 26, the fully open by its initial position Plier insert halves 19 and their end position when the closing gap is reached by pressing the wedge-shaped section 24 ″ between the rollers 21 is.

From the circular washers 27 radially project guide bolts 27 'which in the Slot 29 are guided and prevent rotation of the feed member 24.

The slot 29 is covered on the outside by a hood 30, which at 31 to the side of the Pliers head 5 is flange-mounted and laterally something about the locking ring 9 and that Housing 7 stands out. The hood 30 has an arched cavity 32, the one Allows deformation of the connecting cable 28 when moving the force sensor 26. On the casing of the housing 7 is a bar 33, which has the cross section of half Has circular tube, and one end under the protruding area of the hood 30 is clamped and is clamped at the other end under a plate 34 which is on the outside Control area 4 is screwed tight. Under the bar 33, the connection cable 28 to Control area 4 performed and fixed to the housing 7. Under the plate 34 is at 35 a hose can be clamped, which is led away to the rear and in which the connection cable 28 to an evaluation device and / or to a documentation device to be led. Instead, it is also possible to use an evaluation device and / or documentation device directly in or on the pressure medium pliers accommodate.

The drive area 2 further comprises an arrangement of staggered one behind the other Piston. This includes a compact T-shaped drive piston 36, the by means of a screw 37 on the rear end face of section 24 "of the feed member 24 is fixed. The drive piston 36 is on the outer circumference of the housing 7 sealed and guided axially movable therein.

On the outside of section 24 ″, a sleeve 38 sits next to the piston 36, which limits the movement of the drive piston 36 to the pliers head 5 as a stop. The sleeve 38 thus protects a helical return spring 39 which one end on the drive piston 36 and the other end on an inner edge of the Adjusting ring 6 is supported and strives to drive the piston 36 from the pliers head 5 push away. The return spring 39 pushes the drive piston 36 Pressure relief up to an annular disk-shaped partition 39, which is in the housing 7 is fixed. Further partition walls 40, 41, 42 are fixed in the housing 7.

In the middle openings of the ring-shaped partition walls 39, 40 41 shafts 43, 44, 45 T-shaped drive pistons 46, 47, 48 are each sealingly guided. These have piston disks 49, 50, 51, which seal around the circumference in the housing 7 out and axially movable therein. Since the drive pistons 46, 47, 48 on the drive piston 36 and support each other, they are when the pressure is released from the return spring 39 to abutment on the intermediate walls 40, 41, 42 pushed back.

The drive pistons 46, 47, 48 are provided with central, axially directed bores 52, 53, 54 provided with recesses 55, 56, 57 in the adjacent piston communicate seated ends of the shafts 43, 44, 45.

In the intermediate wall 42, which is adjacent to the control area 4, there is a guide 61 trained. The guide 61 is in the direction of movement of the drive piston 36, 46, 47, 48, i.e. axially aligned in the housing 7. The guide 61 guides a shift rod 62, which protrudes from this on both sides. On the one facing work area 1 End, the shift rod 62 carries a driver 63 in the form of a radial projecting bushing with axial grooves on the circumference. The driver 63 is a Piston-fixed stop 64 in the form of an inner step of the bore 54 assigned.

The other end of the shift rod 62 extends into the control area 4. It is in this direction biased by a coil spring 65, which ends at one an inner step 66 of the intermediate wall 42 and at the other end on one on the shift rod 62 attached ring 67 supports.

The control area 4 takes the associated end of the shift rod 62 in one of these at the same time leading bore 68 of a valve housing 69. The valve housing 69 has a transverse, stepped bore 70 in which a valve pin 71 is seated. The valve pin 71 has a locking seat 72 in the form of an axially directed groove, which can accommodate the end of the shift rod 62. The valve pin 71 has another one axially directed groove 73, in which a housing-fixed alignment pin 74 engages. On At one end, the valve pin 71 is held in a valve bushing 75, in between an O-ring 76 is arranged.

The other end of the valve pin 71 is assigned to a spherical valve body 77, the behind a sealing plug sealed to the valve housing 69 78 is arranged. Between an inner step 79 of the bore 70 and the valve body 77 there is another O-sealing ring 80. The one containing the valve body 77 Section of the bore 70 has a pressure medium connection 81.

A small release pin 82 is guided in the valve pin 71, which is on the switching rod 62 aligned and can be pressed into the locking seat 72. For this purpose, a is in the housing 69 outwardly projecting vent button 83 arranged to counteract the effect a spring 84 can be pressed in and the trigger pin 82 to the switching rod 62 pushes forward.

Is on the outside of the valve housing 69, a protruding end of the valve pin 71 assigned a one-armed trigger lever 85 presented. On this page it has Valve housing 69 has a blind bore in which a further coil spring 86 is seated presses the trigger lever 85 outward.

The valve housing 69 has a cylindrical projection 87 which is associated with the End of the housing 7 is screwed. For this purpose there is a further adjusting thread 88. The further adjusting thread 88 is a threaded ring 89 for one Terminal protection assigned.

This device works as follows: When the trigger is not actuated, all are in position Drive piston 36, 46, 47, 48 in the starting position, i.e. are under the effect of Spring 39 maximally shifted towards control section 4. The shift rod 62 pressed by the pressure of the spring 65 against the valve pin 71. The from Trigger lever 85 unloaded valve pin 71 is from the pressure medium from the pressure medium connection 81 pressed in the direction of the trigger lever 85, but is from the alignment pin 74 or trigger pin 82 secured in the valve housing 69. In this position the shift rod 62 does not engage in the locking seat 72. The pliers halves 19 are pivoted apart as far as possible by the spreading spring 22.

When the trigger lever 85 is actuated, the shift rod 62 snaps first as a result the tension of the spring 65 in the locking seat 72 of the valve pin 71. Then it will be the valve body 77 is pressed out of the seat in the O-sealing ring 80 by the valve pin 71. Pressure medium from the pressure medium connection 81 flows through gaps between Bore 70 and valve pin 71 and a - not shown - bore of the valve housing 69 in the housing 7 and spreads through axial passages of the partition 42 or the through holes 54, 53, 52 and the recesses 57, 56, 55 off, so that all drive pistons 48, 47, 46, 36 to work area 1 be pressed. As a result, the feed member 24 presses with its wedge portion 24 "'the rollers 21 apart and the pliers insert tips 20th pivoted together.

About 1.5 mm before the drive pistons 36, 46, 47, 48 reach their end position in the minimum closing gap between the effect of the feed member 24 the pliers insert halves 19 is set, begins as a result of the driver 63 at the stop 64 pulling out the shift rod 62 from the locking seat 72 of the Valve pin 71.

In the end position of the drive pistons 36, 46, 47, 48, the valve pin 71 is completely free, i.e. when the set closing gap between the tong insert halves 19 is reached the pistons can be vented by releasing the trigger lever 85. Then the compressed air drives valve pin 71 back into the rest position, in the housing 7 via the - not shown - bore of the valve housing 69th and gap between valve pin 71 and bore 70 as well as O-ring 76 and bushing 75 is ventilated to the surroundings. Then the drive pistons 31, 46, 47, 48 of the return spring 39 moves back to the control area 4 and reach their Starting position. In this, the feed member 24 is withdrawn and are the Forceps insert tips 20 pressed apart.

If after actuation of the trigger lever 85, the end position of the drive piston 36, 46, 47, 48 or the minimum closing gap of the pliers insert halves 19 has not yet been reached, the switching rod 62 prevents when the trigger lever is released 85 venting the drive pistons 36, 46, 47, 48 by locking the valve pin 71. The shift rod 62 is then still in the locking seat 72 of the valve pin 71 engaged.

Manual venting is possible at any time by pressing the vent button 83 possible.

The shift rod 62 is released from the locking seat 72 by means of the trigger pin 82 of the valve pin 71 pressed. The venting of the drive piston 36, 46, 47, 48 then takes place as previously described.

A change in the minimum closing gap of the tong insert halves 19 is through an axial displacement of the pliers head 5 to the feed member 24 is possible. By turning the set screw 6, the axial displacement of the pliers head 5 to the wedge 24 "'. Then the pliers head 5 and set screw 6 fixed again by means of the tab 13. The twist around a groove 14 e.g. correspond to a change in the closing gap of 0.1 mm.

A "fine adjustment" of the trigger point of the ventilation is done by turning the Valve housing 69 performed. Previously, it is clamped by means of the threaded ring 89 to solve on the housing 7. After the fine adjustment, the valve housing 69 secured by tightening the threaded ring 89 against the valve housing 69. In addition, the threaded ring 89 and a pressed into the housing 7 Inner ring 90 provided from the outside with a hole into which a screw 91 for Securing the threaded ring 89 is turned in the rotary position. This will the fine adjustment or adjustment secured by the manufacturer during final assembly makes

If the pressure pliers are to be made stronger, there can be between the drive pistons 36 and 48 with a corresponding extension of the tubular housing 7 further drive pistons and partitions can be arranged, like the pistons 46, 47 and the intermediate walls 40, 41 can be formed. So the pliers can Modular to be adapted to the respective requirements.

When the pliers insert tips 20 of the pliers insert halves are pivoted together 19 a force is transmitted via the feed member 24, which also shunts is transmitted via the force sensor 26. This force is linearly dependent on the effective clamping force between the pliers insert tips 20. You will about that Connection cable 28 an evaluation or documentation supplied, whereby a Control over the quality of the clamp assembly is given.

In addition, the compressed air supplied to the pressure medium connection 81 via an im Control area 4 or externally arranged pressure sensor is monitored so that it falls below the predetermined minimum pressure or exceeding a predetermined Maximum pressure a clamping ring assembly is prevented or corrected, where appropriate, the air pressure is automatically adjusted. The Pressure sensor is connected to another - here external - evaluation and / or switching and / or regulation and / or documentation device connected.

Claims (53)

1. Pressurised fluid driven pliers for clamping rings and the like, comprising a control region (4) with a pressurised fluid port (81) and a pressurised fluid valve connected therewith, at least one drive piston (36, 46, 47, 48) controlled by said pressurised fluid valve and a working region (1) with a feed member (24) drivable by the drive piston (36, 46, 47, 48) and swingably mounted tong insert halves (19), upon the inner lever ends of which the feed member (24) acts in order to swing them, the pressurised fluid valve (71, 77) having a valve pin (71), movably guided in the direction transverse to the piston movement and actuatable by a trigger (85), which in a rest position locks the connection of the drive piston (36, 46, 47, 48) with the pressurised fluid port (81) and connects it with a lower pressure level, and which locks the connection of the drive piston (36, 46, 47, 48) with the lower pressure level in a working position attainable by actuation of the trigger (85) and connects it with the pressurised fluid port (81), a selector shaft (62) being slidably kept in a guideway (61) in the direction of the drive piston (36, 46, 47, 48), which is pre-stressed towards the valve pin (71) by a spring (65), the selector shaft (62) having a pusher dog (63) and one drive piston (48) having an abutment (64) assigned to it, in order to carry along the selector shaft (62) during the last portion of its movement for closing the tong insert halves (19), the valve pin (71) having a locking seat (72), into which the selector shaft (62) catches under the action of the spring (65) upon movement of the valve pin (71) from the rest position into the working position and which is released by the selector shaft (62) on its entrainment by the drive piston (48), and a force sensor (26) for measuring a force depending from the locking force of the tong insert halves (19) being disposed in the power flow between the drive piston (36, 46, 47, 48) and the tong insert halves (19), a flexible connecting cable (28) of the force sensor being guided outward through a slit, characterised in that the force sensor (26) is guided in a manner secured against twisting with respect to the moving axis of the feed member (24), that at least one guiding bolt (27') juts out towards the feed member (24) and engages into a slit (29) in the sleeve-shaped tongs head (5) or in a housing portion accommodating the feed member (24), and that a flexible connecting cable (28) of the force sensor (26) is guided through the slit (29) outward of the tongs head (5) or the housing portion.
2. Pressurised fluid driven pliers according to claim 1, wherein the selector shaft (62) has an outer shoulder (63) as pusher dog, and a drive piston (48) has a pierced shaft (45) accommodating the selector shaft (62), with an inner shoulder (64) assigned to the outer shoulder (63) as an abutment for carrying on the selector shaft (62) during the last portion of its movement for closing the tong insert halves (19).
3. Pressurised fluid driven pliers according to claim 2, wherein a partition wall (42) is attached in the housing between pressurised fluid valve (71,77) and drive piston (48), on which the spring (65) supports itself, and the drive piston (489 disposed besides the partition wall (42) is T-shaped and supports the shaft 45, directed towards the feed member (24) and having the inner shoulder, on the following drive piston (47).
4. Pressurised fluid driven pliers according to one of claims 1 to 3, wherein the selector shaft (62) catches into the locking seat (72) before the valve pin (71) reaches its working position.
5. Pressurised fluid driven pliers according to one of claims 1 to 4, wherein a trigger pin (82) is kept in the valve pin (71), which is movable towards the selector shaft (62) through actuation of a vent button (83), in order to push it out of the locking seat (72).
6. Pressurised fluid driven pliers according to one of claims 1 to 5, wherein the valve pin (71) has a longitudinally directed groove (73), into which engages an alignment pin (74).
7. Pressurised fluid driven pliers according to one of claims 1 to 6, wherein the partition wall (42) between pressurised fluid valve (71,77) and drive piston (36, 46, 47, 48) is provided with the guideway (61) for the selector shaft (62).
8. Pressurised fluid driven pliers according to one of claims 1 to 7, wherein the tong insert halves (19) are kept on a sleeve-shaped tongs head (5), the tongs head (5) is kept on the housing (7) by means of an adjustment ring (6), and an adjustment thread (10) for axial adjustment of the tongs head (5) with respect to the feed member (24), and thus of the locking gap between the tong insert halves (19), is formed between the tongs head (5) and the adjustment ring (6).
9. Pressurised fluid driven pliers according to claim 8, wherein the adjustment ring (6) has a flange (8), which is overlapped by a immobilising ring (9) for fixing the adjustment ring (6) on the housing (7)
10. Pressurised fluid driven pliers according to claim 8 or 9, wherein a fixable latch (13) for the fixing of the tongs head (5) and the adjustment ring (6) in different screwing positions is disposed between the tongs head (5) and the adjustment ring (6).
11. Pressurised fluid driven pliers according to claim 10, wherein the latch (13) is detachably screwed on the perimeter of the tongs head (5) with one portion, and is inserted in one of several grooves (12) distributed across the perimeter of the adjustment ring (6) with an other portion.
12. Pressurised fluid driven pliers according to claim 11, wherein the latch (13) is detachably fixed on the adjustment ring (6) by means of a screw upon engagement into a groove (12), said screw penetrating an elongated hole of the latch (13).
13. Pressurised fluid driven pliers according to one of claims 8 to 12, wherein tongs head (5) and adjustment ring (6) have an index and markings for indicating their screwing positions.
14. Pressurised fluid driven pliers according to one of claims 8 to 13, wherein tongs head (5) and adjustment ring (6) have four different angle positions an/or tongs head (5) and adjustment ring (6) have an index and four different markings.
15. Pressurised fluid driven pliers according to one of claims 8 to 14, wherein the adjustment ring (6) is screwable for about one turn in both turning positions, departing from a central position.
16. Pressurised fluid driven pliers according to one of claims 8 to 15, wherein the locking gap is 1,8 mm in a central base position of the adjustment ring (6).
17. Pressurised fluid driven pliers according to one of claims 8 to 16, wherein one turn of the adjustment ring (6) effects a change of the minimal locking gap of the tong insert halves (19) of 4/10 mm.
18. Pressurised fluid driven pliers according to one of claims 8 to 17, wherein the pressurised fluid valve (71, 77) is placed in a valve housing (69), and the valve housing (69) is screwed via a further adjustment thread (88) to the housing (7) on the end of the latter which is opposed to the tong insert halves (19).
19. Pressurised fluid driven pliers according to claim 18, wherein the further adjustment thread (88) carries a threaded ring (89) for securement of the thread connection between valve housing (69) and housing (7) in different screwing positions.
20. Pressurised fluid driven pliers according to one of claims 1 to 19, which has several drive pistons (36, 46, 47, 48) graduated in a row, with have a T-shape and a pierced shaft.
21. Pressurised fluid driven pliers according to one of claims 1 to 20, wherein the force sensor (26) measures a force on the feed member (24) which depends of the locking force of the tong insert halves (19).
22. Pressurised fluid driven pliers according to one of claims 1 to 21, wherein the force sensor (26) is integrated into the feed member (24).
23. Pressurised fluid driven pliers according to one of claims 1 to 22, wherein the force sensor (26) is plate-like and disposed transverse to the flow of power on the feed member (24).
24. Pressurised fluid driven pliers according to one of claims 1 to 23, wherein the cross section of the power sensor (26) is about conincident with the maximal cross section of the feed member (24).
25. Pressurised fluid driven pliers according to one of claims 1 to 24, wherein the power sensor (26) is kept in a central hole of a bolt (25) which extends into the direction of the flow of power and is anchored in the feed member (24).
26. Pressurised fluid driven pliers according to one of claims 1 to 25, wherein the power sensor (26) is disposed between a portion (24") co-operating with the drive piston (36) and a portion (24') co-operating with the lever ends of the tong insert halves (19) of the feed member (24).
27. Pressurised fluid driven pliers according to the claims 25 and 26, wherein the bolt (25) is anchored in the two portions (24, 24") of the feed member (224) with its two ends and keeps the power sensor between the two portions (24, 24") of the feed member (24).
28. Pressurised fluid driven pliers according to one of claims 23 to 27, wherein the power sensor (26) is washer-shaped.
29. Pressurised fluid driven pliers according to one of claims 25 to 28, wherein perforated disks (27) sit on the bolt (25) on both sides of the power sensor (26) and the flow of power through the power sensor (26) takes place via the perforated disks (27).
30. Pressurised fluid driven pliers according to claim 29, wherein the perforated disks are washers (27).
31. Pressurised fluid driven pliers according to one of claims 1 to 30, wherein the power sensor (26) is mounted on the feed member (24) under pre-stress.
32. Pressurised fluid driven pliers according to claim 31, wherein the power sensor (26) is pre-stressed by screwing the bolt (25) in the feed member (24).
33. Pressurised fluid driven pliers according to one of claims 29 to 32, wherein a screwing of the bolt (25) in the feed member (24) is equipped with a slew lock.
34. Pressurised fluid driven pliers according to one of claims 1 to 33, wherein a flexible connecting cable (28) of the power sensor (26) is guided outward through a slit (29) extending into the direction of movement of the feed member (24) into the sleeve-shaped tongs head (5), or in a housing portion accommodating the feed member (24).
35. Pressurised fluid driven pliers according to claim 34, wherein the slit (29) extends across the whole region of movement of the force sensor (26) with the feed member (24).
36. Pressurised fluid driven pliers according to claim 34 0r 35, wherein the outward guided portion of the connection cable (28) is fixed on the housing (7).
37. Pressurised fluid driven pliers according to one of claims 33 to 35, wherein the slit (29) is covered on the outside by a cap (30) fixed on the housing, which has a cavity (32), in which the connection cable (28) can deform itself upon movement of the feed member.
38. Pressurised fluid driven pliers according to one of claims 1 to 37, wherein a connection cable (28) of the force sensor (26), connected with a pressurised fluid hose, is guided away from the pressurised fluid driven pliers.
39. Pressurised fluid driven pliers according to one of claims 1 to 38, wherein at least one guiding bolt (27') is guided in the slit (29) besides the flexible connection cable (28), through which slit the connection cable is guided towards the outside at the same time.
40. Pressurised fluid driven pliers according to one of claims 1 to 40, wherein the force sensor (26) is a wire strain gauge- and/or a piezo- sensor.
41. Pressurised fluid driven pliers according to one of claims 1 to 40, which is provided with a pressure sensor for monitoring the pressure of the pressurised fluid, and in which the pressure sensor is connected with an evaluation equipment.
42. Pressurised fluid driven pliers according to claim 41, wherein the pressure sensor is integrated in the pressurised fluid valve (71, 77).
43. Pressurised fluid driven pliers according to claim 42, wherein the pressure sensor is integrated in the pressurised fluid port (81).
44. Pressurised fluid driven pliers according to claim 43, wherein the pressure sensor is integrated in a pressurised fluid duct which is connected with the pressurised fluid port (81).
45. Pressurised fluid driven pliers according to one of claims 1 to 44, wherein the force sensor (26) and/or the pressure sensor is connected with an evaluation equipment.
46. Pressurised fluid driven pliers according to claim 45, wherein the evaluation equipment controls a display for the locking force and/or the pressure of the pressurised fluid, and/or controls means for switching off the pressurised fluid driven pliers when an allowed value for the locking force and/or an allowed value for the pressure is not observed, and/or controls means for the adjustment of pressure up to the obtainment of a predetermined value for the locking force and/or a predetermined value for the pressure, and/or supplies the measured values of the locking force and/or the pressure to a documentation equipment.
47. Pressurised fluid driven pliers according to claim 45 or 46, wherein the display is an optical and/or an acoustical display.
48. Pressurised fluid driven pliers according to one of claims 45 to 47, wherein the evaluation equipment and/or the equipments supplied by it are electrical equipments.
49. Pressurised fluid driven pliers according to one of claims 1 to 48, which is realised as a hand-held device.
50. Pressurised fluid driven pliers according to one of claims 1 to 49, wherein a series of drive regions with different numbers of drive pistons (36, 46, 47, 48), graduated in a row, for the obtainment of different locking forces are provided, the working region (1), the control region (4) and the feed member (24) with integrated force sensor (26) being the same.
51. Pressurised fluid driven pliers according to one of claims 1 to 50, with one or several tramming equipments for measuring the locking gap.
52. Assembly kit system with pressurised fluid driven pliers according to one of claims 1 to 51, which comprises pressurised fluid driven pliers which are provided with different numbers of drive pistons (36, 46, 47, 48), graduated in a row, but in which the feed member (24) with the force sensor (26), and a working region (1) being provided with the tong insert halves (19) and a control region (4) being provided with a triggering lever (85) and a pressurised fluid valve (71, 77), do coincide.
53. Assembly kit system with pressurised fluid driven pliers according to one of claims 1 to 52, which comprises pressurised fluid driven pliers with a force sensor and/or a pressure sensor and/or an evaluation equipment and/or a display and/or means for switching off and/or means for pressure control and/or equipment for documentation.

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