EP3068693B1 - Portable tool for applying cable straps - Google Patents

Description

The invention relates to a portable tool for binding an object, in particular a wiring harness, by means of a belt, which has a tool body with cycle control arranged therein as well as clamping device and a drive for this purpose.

In known cable binding tools, as in the main features, for example, from the EP 0 428 116 A1 are known, a drive is provided which actuates a cycle control. This serves to carry out the different movements to be performed by the cable tie tool in a controlled sequence in the context of a working cycle. This includes in particular the closing of a Umgreifungszange of the tool, in which the tape is led to wrap around the object to be bound, the insertion of the free end of the tape in the located on the rear band lock and the cutting of the protruding tape end and finally the opening of the wrapper.

These operations to be performed during the working cycle in a controlled sequence also include the tensioning of the band guided around the object to be bound by means of a tensioning device. It serves to attract the tape with a generally predetermined tape tension. For this purpose, various types of clamping devices are known, for example, one with a tension roller, which is provided with sharp teeth and engages in the surface of the existing plastic strip ( EP 0 432 477 A1 ). When the band reaches its predetermined band tension, the tensile force exerted by the teeth of the tensioning roller is no longer sufficient for further movement, so that the band stands still and the teeth of the tensioning roller mill into the band surface. Even if the inevitable weakening of the strip material in practice is usually not disturbing, the resulting abrasion is distracting. This problem is avoided in another type of clamping device, in which the limit voltage to be reached is adjusted by means of a slip clutch ( US 4,610,076 A ). In such a slip clutch, there is the problem of diminishing reproducibility due to wear. Although this avoids abrasion as in the former solution, it suffers from the uniform quality of the belt tension.

From the US 4,790,225 is a portable tool for binding an object, in particular a wiring harness, known by means of a belt comprising a tool body, comprising a first drive comprehensive, arranged in the tool body cycle means and comprising a clamping device comprising a second drive. The first and the second drive form a double drive and a control device is provided which independently controls the first and second drive. Other devices which belong to the prior art are known from the documents US 2009/0242069 A1 . EP 0 839 717 A1 and US 2002/0129866 known.

The invention has for its object to provide an improved, portable tool, which achieves a more precise compliance with the desired belt tension, even at high operating speeds.

The solution according to the invention lies in a tool having the features of the independent claim. Advantageous developments are the subject of the dependent claims.

In a portable tool for binding an object, in particular a wire harness, by means of a belt which has a tool body with a cycle control and a tensioning device arranged therein and a drive for this, it is provided according to the invention that the cycle control has a first drive, which via a reduction gear is connected to a Kurvensteuerscheibe and drives the Kurvensteuerscheibe that the Kurvensteuscheibe drives several devices to perform a plurality of operations in a controlled order that the drive is designed as a double drive such that the cycle control via the first drive and the tensioning device via a second drive are driven, each having its own drive, and that a control device is provided which controls the first and second drives independently of each other.

The invention is based on the idea to provide for the cycle control on the one hand and the clamping device on the other hand each have their own drive. By thus providing a separate drive for the tensioning device, it is free from interference caused by the cycle control. It can thus be a more precise clamping by means of the clamping device. The desired belt tension can be achieved more accurately, so that the fastening quality increases. The result of the binding process is thus a tight fit with high reproducibility with respect to the belt tension. Preferably, a torque control device for driving the tensioning device is provided. It allows precise monitoring of the torque acting on the tensioning device and thus also of the belt tension caused. It can thus be controlled during clamping in real time, the actual band tension achieved. The reproducibility is thus further increased. Furthermore, such torque control allows demolition detection. A demolition is characterized by the fact that after an increase in the moment of the clamping device this abruptly drops, since there is no more tape tension after the band break. Such demolition detection considerably increases process reliability.

Preferably, a synchronous control is provided for the two drives, which expediently has such a torque control device.

Advantageously, the drive of the clamping device comprises a backstop. This prevents that in unfavorable conditions, as they can occur especially when bonding elastic materials, it is an undesirable Return of the tape can come. The backstop can be designed as a worm gear in the drive.

Conveniently, a current monitoring module for an electric drive of the clamping device is provided. With such a current monitoring, the torque applied by the drive of the tensioning device can be monitored in a particularly efficient manner. Mechanical sensors for torque determination are therefore superfluous. In such a current monitoring and the demolition detection can be integrated in an advantageous manner.

Preferably, the clamping device is designed so that it acts positively by means of a blunt tensioning wheel on the band. By "blunt" is meant here that the tensioning wheel does not have such teeth which cut into the band, and in particular do not mill into the band upon reaching the desired band tension. Rather, the teeth engage in a form-fitting manner in the correspondingly complementarily shaped surface of the band, such as a gear in a toothed belt. For a secure hold of the tape is achieved and it is so a reliable coupling of the tape causes the tensioning device and the torque monitoring. This further improves the process quality and thus the reproducibility of the belt tension.

Expediently, encoders for an actual rotational speed are arranged on the clamping device and on the cycle control. Thus, the actually achieved drive speed can be detected and transmitted to the control device. Preferably, the control device is designed to set a fixed speed relation of cycle control on the one hand and clamping device on the other hand. This will be achieves a reliable synchronization of the processes, which further increases the reproducibility and reliability of the binding process.

Advantageously, the controller has a characteristic module, which is designed to set different speed / torque characteristics. Thus, by selecting the characteristic different degrees or fast (depending on the cycle time) clamping operations can be performed. The characteristic curve module expediently comprises a lookup table, which in particular can contain the corresponding parameters for different chip strengths and speeds (cycle times) in the form of a matrix. Thus, speed ratios for tensioning operations in various strengths (for example, thicknesses 1 to 5) as well as for different quality levels (for example, 1 to 3) can be maintained. Such a parameter matrix allows the operator, depending on the application, to simply and reliably load a suitable parameter set into the control device.

It is particularly preferred if the control device further comprises a dynamic module. This is designed to slow down in a selectable section of the clamping operation, preferably the last section, the tensioning drive. Thus, in the particularly critical moment of reaching the set tape tension, the process can be carried out more slowly so as to reduce unwanted dynamic effects due to high tape speed. This further increases the reproducibility.

Thanks to the inventive separation of the drives of cycle control on the one hand and clamping device on the other hand, this can be done without the slowing down of the tensioning drive to an undesirable slowdown of the Cycle control leads. The dynamics module is so far capable of picking up the fixed speed ratio in a controlled manner. This achieves an increase in binding quality and reliability without having to be paid for by a longer cycle time.

Furthermore, the portable tool preferably has a memory device which comprises data sets for maximum current, average current, holding duration and / or cycle time of the clamping operation. This achieves documentability of the clamping process. Since, owing to the inventive separation of the tensioning drive from the cycle control, the power taken up by the tensioning drive exclusively serves for the belt tension, it can thus be achieved in an expedient and efficient manner by simple measurement of the power consumption of the tensioning device. Disturbing factors due to other processes of the cycle control, for example due to friction of the belt, therefore do not interfere. Thus, a meaningful documentation of high quality can be achieved in a surprisingly simple way. The quality of setting is thus comprehensible and can be evaluated within the scope of customary measures, for example a statistical process monitoring. This can also be done locally by the respective control device as part of a demolition detection of the tape.

The data sets stored in the memory device can also be provided for external further processing. For this purpose, an interface is expediently provided, via which the data records can be read from the storage device and fed to a process monitoring unit.

Fig. 1

eine Seitenansicht eines portablen Bindewerkzeugs;

Fig. 2

eine Teil-Explosionsansicht zu dem Werkzeug nach Fig. 1;

Fig. 3

eine Blockdarstellung zur Steuerung; und

Fig. 4

eine Detailansicht zur Spannrolle.

The invention will be explained in more detail with reference to the accompanying drawings with reference to an embodiment. Show it:

Fig. 1

a side view of a portable binding tool;

Fig. 2

a partial exploded view of the tool after Fig. 1 ;

Fig. 3

a block diagram for the control; and

Fig. 4

a detailed view of the tension roller.

A portable binding tool is provided in the illustrated embodiment for processing cable ties 9. The binding tool comprises a tool body 1 with a pistol-like handle at its lower end. At its upper end a removable magazine 2 is provided, which receives the cable tie 9 to be supplied. On a front side of the tool body 1, a pair of pliers 3 is arranged, which consists of two relatively movable pliers halves 30, 31. On its side surface, the tool body on a control panel 18 with a display and input keys. For power supply, a power supply 10 is provided.

In operation, the object to be bound (harness 99) is inserted between the open tong halves 30, 31. The pliers halves 30, 31 move towards each other, so that the pliers 3 is closed. In this case, a cable tie 9 with its free end ahead by a guide (not shown) advanced on the inside of the pliers 3 and so guided around the harness 99 until the free end runs back to the tool body and there enters a arranged at the rear end of the cable tie 9 lock. The free end led through the lock is grasped and stretched, finally the protruding part of the band is cut off and ejected. At the end, the pliers 3 is opened and the cable strand 99 looped around by the cable tie 9 can be removed.

To effect these operations, a cycle control 5 and a tensioning device 6 are arranged in the tool body 1. They are in an exploded view together with a chassis element 4 carrying them Fig. 2 shown. The cycle controller 5 has a first drive 75 in the form of an electric motor. It is connected via a multi-gear reduction gear 51 with a cam plate 50 and drives it. Of this curve control disc 50, a plurality of non-detailed devices are driven, which - except for the tensioning - the above individual operations (feeding a cable tie, advancing in the pliers, insertion into the lock, separation of the protruding part and ejection) in a controlled order To run.

For effecting the clamping, a separate tensioning drive 6 is provided according to the invention. It is arranged opposite the cycle control 5 on the chassis element 4 in the illustrated embodiment. It included a second, own drive 76, via a reduction gear 61 and a toothed belt drive 62 with rollers 63, 64 at each end. The roller 64 drives via a reduction gear 65 to a tensioning roller 60, which engages with its outer circumference, the band of the cable tie 9 and advances (s. Fig. 4 ). The tensioning roller 60 opposite two support rollers 66 are arranged, which form an abutment for tensioning roller 60. The band of the cable tie 9 is performed between the tension roller 60 and the support rollers 66. The tension roller 60 is provided on its outer circumference with blunt gripping teeth 69, which engage in a form-fitting manner in a ribbing provided on the upper side of the strip and thus ensure functionally reliable advancement and clamping. Thanks to the positive engagement, there is no slip between the tension roller 60 and the belt 9, so that the emergence of abrasion and a weakening of the belt 9 is avoided.

Optionally, a backstop 67 may be provided in the tensioning drive 6 (integrated into the tensioning roller 64 in the example shown, but it may also be arranged elsewhere).

The separate drives 75 and 76 are controlled via a control device 8. It is designed to synchronize the operation of the tensioning drive 6 with the cycle control 5. For this purpose, a synchronous control module 82 is provided. The signals applied by encoders 85, 86 for the actual rotational speeds of the drives for cycle control 5 or the tensioning device 6 are applied as input signals. By measuring the current for the drive 76 by means of a current sensor 80, the clamping force exerted by the tensioning device 6 on the belt 9 can be determined. If a predetermined value is reached, the current and thus the clamping force over a certain Time is maintained until the cycle control to complete the binding process, a clipping of the excess band remainder is performed.

In order to adapt to various applications, the control device 8 also contains a characteristic module 83. It comprises a parameter matrix 84 executed as a lookup table. Depending on a clamping force selected via the control panel 18 (for example stages 1 to 5) and the desired setting quality (for example stages 1 to 3), the corresponding parameter set is loaded from matrix 84 and used by the controller. Depending on the set of parameters, another fixed relation for the speeds of cycle control 5 on the one hand and tensioning drive 6 on the other hand is set. At higher clamping forces, a higher current is parameterized for the drive 76 of the clamping device, and with higher quality, the cycle time is increased, thus reducing the working speed of the tool.

In order to achieve a secure binding even with small dimensions of the object to be bound 99 even in rather problematic applications, such as low clamping force at low quality (ie a particularly short cycle time), a dynamics module 87 is provided. It is designed to perform the last portion of the tensioning process at a lower speed under critical operating conditions such as those described above. This avoids unfavorable dynamic effects due to the inherently high operating speed (due to the short cycle time). Since this speed reduction is made only a relatively small section, there is no noticeable increase in the cycle time. Thanks to the separately executed drive 76 the tensioning device remains without influence on the clamping force.

Connected to the control device 8 is a memory device 88. It stores data records for the tensioning operations performed. These include information on maximum current during clamping, the average current actually achieved during clamping, the holding time and the cycle time. This information can be evaluated, for example by means of statistical process control. The data records can be read out for external processing, in particular for documentation purposes, via an interface 89. The interface may be located on the tool itself or on the power supply 10, for. B. in the form of a USB socket 89 '. However, the read-out may also be carried out on the tool itself by interrogating the corresponding results via the control panel 18.

Claims (12)

1. A portable tool for tying an object, in particular a cable harness, using a strap, including a tool body (1) with a cycle means (5) disposed within the tool body and including a first drive (75) and a tensioning means (6) including a second drive (76), wherein the first drive (75) is provided as electrical motor connected by a reduction gear (51) including a plurality of gear wheels to a curve control plate (50), and wherein the cycle means (5) provides an order of operation steps to be carried out, namely feeding a cable tie, advancing in the gripper, inserting into the lock, cutting-off the projecting part and ejecting, wherein the first drive (75) and the second drive (76) form a dual drive and wherein further a controller is provided for driving the first and second drive (75, 76) independently.
2. The portable tool of claim 1,
   characterized in that
   a torque controller is provided for the second drive (76) of the tensioning means (6).
3. The portable tool of claim 1 or 2,
   characterized in that
   a synchronous controller (82) is provided for the first and second drives (75, 76).
4. The portable tool of any of the preceding claims,
   characterized in that the second drive (76) of the tensioning means (6) is configured as electrical motor and a current monitoring module (81) is provided for the second drive (76).
5. The portable tool of any of the preceding claims,
   characterized in that
   the tensioning means (6) comprises a tensioning wheel (60) which is configured for engaging the strap (9) in a form-fitting manner, preferably using blunt teeth.
6. The portable tool of any of the preceding claims,
   characterized in that
   encoder (85, 86) for an actual revolution speed are disposed at the cycle control (5) and the tensioning means (6).
7. The portable tool of claim 6,
   characterized in that
   the controller (8) is configured for setting a fixed revolution speed relation between the cycle control (5) and the tensioning means (6).
8. The portable tool of any of the preceding claims,
   characterized in that
   the controller (8) comprises a characteristic-curve module (83) which is configured for setting various characteristic curves for revolution speed/ torque.
9. The portable tool of claim 8,
   characterized in that
   the characteristic-curve module (83) includes a lookup table (84), preferably comprising a parameter matrix for various tensioning forces and speeds.
10. The portable tool of any of the preceding claims,
    characterized in that
    the controller (8) comprises a dynamics module (87) which is configured for decelerating the second drive (76) of the tensioning means (6) in a selectable portion, preferably the last portion, of the tensioning procedure.
11. The portable tool of any of the preceding claims,
    characterized in that
    a storage means (88) is provided comprising data sets of maximum current, average current, holding time and/or cycle time of the tensioning procedure.
12. The portable tool of claim 11,
    characterized in that
    the storage means (88) comprises an interface (89) for external subsequent processing which may be disposed at the tool or an external component, in particular a power-supply unit (10).

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