Screw device and hand-held screw system

Abstract

The invention relates to a screw device for applying torque to a screw partner (12), comprising flat output assembly (10) provided with an output member that can be detachably connected to the screw partner and a drive to which a drive torque can be manually or mechanically applied, particularly by an interconnected angular and/or bevel gear (16), and an assembly (48) for detecting an output torque acting on the screw partner on the output side, the detection assembly associated with the flat output assembly and particularly provided on and/or in a housing (30 32) of the flat output assembly being designed such that it can detect an axial force acting on a helical gear (38) connecting the drive and the output member of the flat output assembly in a torque-transmitting manner and provide same for preferably electronic signal evaluation.

Claims

1. A screwing device for applying a torque to a screwing partner (12), the screwing device comprising flat output means (10) having an output which is detachably connectable to the screwing partner and a drive to which a driving torque can be applied manually or mechanically, via an interposed angular and/or bevel gearing (16), and comprising means (48) for detecting an output torque acting on the screwing partner at the output side, wherein the detecting means assigned to the flat output means and provided in particular on and/or in a housing (30, 32) of the flat output means are configured in such a manner that they detect an axial force acting on a helical gear wheel (38) which connects the drive and the output of the flat output means in a torque-transmitting manner, and can make said axial force available for signal evaluation.

2. The device according to claim 1, wherein the flat output means have the helical gear wheel (38) between a drive module (20), which has teeth and which forms the drive, and an output module (24), which has teeth and which forms the output, or wherein the helical gear wheel forms the output module.

3. The device according to claim 2, wherein a plurality of gear wheels (34, 36, 38) forming a gear assembly between the drive and the output are provided between the drive module and the output module.

4. The device according to claim 3, wherein the helical gear wheel meshes with the output module (24).

5. The device according to claim 1, wherein the helical gear wheel (38) is mounted to rotate about an axis of rotation (52) which extends at an angle of ≥45° to a longitudinal axis of the flat output means, the detecting means (48) detecting the axial force by the effect of a gear wheel shaft (40, 42) which forms the axis of rotation and/or at the edge of the teeth of the helical gear wheel.

6. The device according to claim 5, wherein the angle is 90°.

7. The device according to claim 1, wherein the detecting means are realized as pressure and/or force sensor means (48) which are assigned to the helical gear wheel (38) in a force-fitting manner.

8. The device according to claim 7, wherein the pressure and/or force sensor means are realized as a piezoelectric force sensor (48) or by strain gauges.

9. The device according to claim 7, wherein the pressure and/or force sensor means (48) are assigned to the helical gear wheel (38) in an axially adjacent manner.

10. The device according to claim 7, wherein the pressure and/or force sensor means (48) are supported on a housing side and/or flat side (30) of the flat output means.

11. The device according to claim 1, wherein the detecting means have means for signal transmission of a detection signal corresponding to the detected output torque.

12. The device according to claim 11, wherein the means for signal transmission are means for wireless signal transmission of the detection signal corresponding to the detected output torque.

13. The device according to claim 1, wherein the detecting means have hydraulic or pneumatic means which translate the axial force into a fluid pressure and which establish fluid communication with a fluid pressure sensor.

14. The device according to claim 13, wherein the hydraulic or pneumatic means are provided on or in a gear wheel shaft realizing the axis of rotation of the helical gear wheel.

15. The device according to claim 13, wherein the fluid pressure sensor is assigned to a housing of the flat output means.

16. The device according to claim 15, wherein the fluid pressure sensor is on or in said housing.

17. The device according to claim 1, wherein the detecting means have electronic interface means and/or signal processing means and electrical energy supply means.

18. The device according to claim 17, wherein the electrical energy supply means are realized as electric generator means interacting with a mobile, rotating, component of the flat output means.

19. Handheld screwing system having the screwing device according to claim 1, wherein and driving torque generating means (18) connected to the flat output means at the driving side.

20. The device according to claim 1, wherein said signal evaluation is electronic signal evaluation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, features and details of the invention can be derived from the following description of preferred exemplary embodiments and from the drawings.

(2) In the following,

(3) FIG. 1 is a perspective view of the handheld screwing system according to the invention according to a first preferred exemplary embodiment of the invention;

(4) FIG. 2 is a schematic lateral view (housing is removed) of the flat output means according to the invention comprising an upstream angle head;

(5) FIG. 3 is a detailed view by analogy with FIG. 2 comprising the assembly of gear wheels realizing the flat output means;

(6) FIG. 4 is a longitudinal sectional view of FIG. 3, also comprising the halves of the housing of the flat output housing enclosing the gear wheels;

(7) FIG. 5, FIG. 6 are perspective views of the assembly of gear wheels according to FIG. 2, FIG. 3, FIG. 5 showing an exploded view of the gear wheel which is used for the torque detection relative to the detecting means and FIG. 6 being a view in the assembled state;

(8) FIG. 7 is a detailed view of the detecting means configured as a pressure or force sensor in the assembled state and

(9) FIG. 8 is a detailed sectional view of the helical gear wheel used for detecting the torque in the assembled state of the pressure or force sensor, i.e. a detailed view of FIG. 4.

DETAILED DESCRIPTION

(10) FIG. 1, which is the system and, at the same time, context view for the present invention, shows the perspective view of the screwing device for applying a torque to a screwing partner according to a first exemplary embodiment of the invention comprising flat output means 10 accommodated in a housing 30, 32 which drive a corresponding screwing tool 14 as a screwing partner (not part of the invention) in order to interact with a screw 12 at one end (at the output side). At the driving side, i.e. at the end of the flat output means opposite the output), said flat output means are connected to a screwing tool 18 which can be manually operated via an angle head 16 which comprises a pair of bevel gear wheels; said screwing tool, as a conventional tool which is offered by different tool manufacturers, can apply a torque, which is applied by a motor (e.g. electrically or pneumatically) and which is deflected by a right angle by a module 16, to flat output means 10 which transmit said drive to a tool 28 for the screwing of connecting element 12 in a manner which will be described below.

(11) The mechanical realization and functionality of the flat output means in the illustrated screwing device can be described, in particular, by the lateral or longitudinal sectional views of FIGS. 2 to 4. It shows that a drive module 20 in the form of a first helical gear wheel is formed at the driving side at the flat output means which is connected to angle head 16 in a torque-transmitting manner (FIG. 2) and to which (FIG. 3, FIG. 4) the driving torque can be applied by a flange section 22 which is configured in one piece.

(12) At the other end (at the output side) of flat output means 10, an output module 24, also in the form of a helical gear wheel, is provided, which can apply the output torque of the flat output means to the screwing partner by means of a square head or tool section 26 (FIG. 3, FIG. 4) and a drive sleeve 28 (FIG. 2) which is connectable thereto in a non-rotatable manner.

(13) A meshing assembly of intermediate helical gear wheels is provided between drive module 20 and output module 24 which are mounted so as to be rotatable and axially parallel to one another in the housing of the flat output means which are formed of housing halves 30, 32 in such a manner that a gear transmission 1:1 is realized between drive module 20 and output module 24; as it is the case for the two modules, intermediate gear wheels 34 to 38 are each axially parallel to one another and disposed in a line-like manner along a longitudinal extension of housing 30, 32 so as to be rotatable in said housing.

(14) According to a typical realization for a manual screwing, such flat output means for transmitting a maximum torque of approx. 200 Nm are provided and adequate; depending on the lubrication conditions and the configuration of the gearings, a normal efficiency of such a helical device is between approx. 80% and 90% (i.e. the ratio of a torque at the output side at 24 in relation to a torque at the driving side at 20).

(15) The lateral or sectional views of FIGS. 2 to 4 show that detecting means are provided at gear wheel 38 which is directly adjacent to output module 24 (and which meshes with the output module), said detecting means detecting an axial force acting on gear wheel 38 (i.e. a force which is generated along the axis of rotation of gear wheel 38 and therefore perpendicular to a longitudinal extension of housing 30, 32—thus extending vertically to the layer of FIGS. 2 to 4—and by the action of the helical gearing which is subject to rotary loading).

(16) More specifically and additionally referring to the detailed or exploded views of FIGS. 5 to 8, gear wheel 38 which has shaft sections 40, 42 which are axially configured in one piece at both ends in a contacting manner (and which form pivot bearings for respective housing shells 32 or 30 by means of annular plates 44 or 46) is assigned a force sensor 48 in an axial manner at one end, said force sensor absorbing an axial force of gear wheel 38 by means of a bearing/plate assembly 50 at the sensor side (i.e. in an upward direction along axis 52 in the drawing layer of FIG. 8) and being axially supported by a sensor cover 54 at the other end, said sensor cover being fixed at upper cover shell 30 by means of the illustrated screw connection.

(17) An axial bias (correspondingly transmitted to force sensor 48) is applied to gear wheel 38 via a plain bearing assembly 60 by a compression spring 56 which is supported by a cover module 58 which is screwed to lower cover shell 32. With respect to a desired operating point, sensor 48 which is configured, for example, as a piezo force sensor is biased by a corresponding configuration of compression spring 56. Concerning a specific realization of a torque of approx. 220 Nm to be transmitted by flat output means 10 of the illustrated exemplary embodiment, a force to be absorbed by force sensor 48 can be 3000 N or higher. Typical and conventional force sensors are produced, for example, by Kistler AG (CH-Winterthur), in the illustrated exemplary embodiment type Slimline having a typical maximum outer diameter of 12 mm.

(18) In particular the exploded perspective view of FIG. 5 shows the respective components in direct comparison to the assembled state (FIG. 6, FIG. 7, FIG. 8), the torque detection signal which is made available for a subsequent processing and evaluation in a manner known per se coming into contact with a cable connection 62 of force sensor 48. FIGS. 6 and 7 show the assembly when cover 54 is removed.

(19) Field tests relating to a wide operating range (torque range) have shown that a force measurement signal (as signal voltage) generated by force sensor 48 is proportional to the torque being in contact with gear wheel 38 in an almost ideal manner (thus having an almost linear signal performance). Since gear wheel 38 meshes directly with the outer gearing of the output module (which applies the output torque directly to the screwing partner for the purpose of screwing) in the illustrated exemplary embodiment, the force sensor signal can represent the actual torque ratios on the output side at the flat output means in a very accurate, interference-free and reproducible manner in order to attain the object of the invention—the loss of the torque combination being negligible. Furthermore, this shows that it is realized without a significant increase in installation space or volume of flat output means 10 or of housing 30, 32, the present invention thus combining said advantages relating to the measurement with the best compactness and minimization of the requirements relating to the installation space.