Spring element on coupling device

Abstract

A power tool, in particular a tube press, comprises a drive, a transmission, a threaded spindle drive and a linear actuator, wherein a torque generated by the drive can be transmitted to the linear actuator via the transmission and the threaded spindle drive. The power tool comprises a coupling device for converting rotational movement generated by the transmission from the transmission to the threaded spindle drive into linear movement to be transmitted to the threaded spindle drive, wherein at least one spring element is included for reducing torsional forces acting on the coupling device.

Description

Technical Field

[0001] The present invention relates to a power tool, particularly a pipe press, comprising a driver, a transmission, a threaded spindle driver, and a linear actuator, wherein torque generated by the driver can be transmitted to the linear actuator via the transmission and the threaded spindle driver. Background Technology

[0002] Various power tools are known in the prior art for deformation and cutting processes. These specialized power tools can be used, for example, to cut reinforcing bars, mechanically connect pipes, or press hose clamps. Mechanical connection tasks also include so-called crimping, flanging, and extrusion.

[0003] To achieve the high pressing force required for steel pipe crimping, commercially available crimping machines, for example, have a press head driven by a cylinder. Here, the cylinder is typically hydraulically driven to move the press head. An electric motor then drives a hydraulic pump, which outputs the linear motion of the cylinder. Alternatively, commercially available mechanical pressing, cutting, and crimping tools replace the hydraulic system, generating pressing pressure by means of a threaded spindle drive and an electric motor. Here, the rotational motion of the electric motor is converted into linear motion of a linear actuator by means of a threaded spindle. These power tools typically include a transmission mechanism connecting the threaded spindle drive and the electric motor and used to reduce the required motor torque, thereby enabling a smaller motor size.

[0004] However, these power tools known from the prior art typically suffer from the problem that the threaded spindle drive is subjected to relatively high mechanical loads when it is in its fully extended or fully retracted position. These two extreme positions of the threaded spindle drive are also referred to as "reaching the limit." In this state, relatively high forces and torques are applied, particularly to the motor, transmission, coupling, threaded spindle drive, and linear actuator. Simultaneously, the motor is subjected to high current intensities (known as interrupting current). The high forces, high torques, and high current intensities can lead to permanent damage to the power tool. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a power tool, particularly a pipe press, comprising a driver, a threaded spindle driver, and a linear actuator, to solve the above-mentioned problems.

[0006] In particular, this objective is achieved by providing a power tool, especially a pipe press, as described in this invention, which includes a driver, a transmission, a threaded spindle driver, and a linear actuator, wherein the torque generated by the driver can be transmitted to the linear actuator via the transmission and the threaded spindle driver.

[0007] According to the invention, the power tool includes a coupling device for converting the rotary motion generated by the transmission device from the transmission device to the threaded spindle drive into linear motion to be transmitted to the threaded spindle drive, wherein at least one spring element is included for reducing the torque acting on the coupling device.

[0008] According to an advantageous exemplary embodiment, the coupling device may have a sleeve and a piston for converting the rotational motion generated by the transmission from the transmission to the threaded spindle drive into linear motion to be transmitted to the threaded spindle drive, wherein a toothed profile for connecting the piston to the sleeve to rotate therewith is included between the sleeve and the piston, resulting in the piston being arranged in a manner that allows it to move axially relative to the sleeve and rotate with the threaded spindle drive, and wherein the at least one spring element is an integral part of the piston.

[0009] As a result, the spring element can be positioned in the coupling device in a particularly space-saving manner.

[0010] According to an advantageous exemplary embodiment, the at least one spring element can be implemented as a torsion bar spring. As a result, the functions of the spring element and the piston can be combined particularly efficiently in a single component, and installation space within the power tool can be saved. A torsion bar spring can also be referred to as a torque spring.

[0011] According to a further advantageous exemplary embodiment, the spring element can be implemented as a first rotating helical spring and a second rotating helical spring, wherein the first rotating helical spring and the second rotating helical spring are arranged relative to each other such that the corresponding turns of the two rotating helical springs extend in opposite rotational directions. Attached Figure Description

[0012] Further advantages will become apparent from the following description of the accompanying drawings.

[0013] Various exemplary embodiments of the present invention are shown in the accompanying drawings.

[0014] The accompanying drawings, description, and patent claims contain many combinations of features. Those skilled in the art will also readily consider these features individually and combine them to produce useful further combinations.

[0015] In the accompanying drawings, identical and similar parts and components are indicated by the same reference numerals.

[0016] Specifically:

[0017] Figure 1 A side view of a power tool in the form of a tube press according to the present invention is shown;

[0018] Figure 2 A cross-sectional side view of a power tool in the form of an example tube press is shown, the power tool having a drive, coupling device, threaded spindle drive, linear actuator and transmission device;

[0019] Figure 3 A three-dimensional cross-sectional view of the transmission device, a portion of the connecting device, and the first and second bearings is shown.

[0020] Figure 4 A three-dimensional cross-sectional view of the connecting device is shown; and

[0021] Figure 5 A cross-sectional side view of a portion of the interior of a power tool in its first state is shown. Detailed Implementation

[0022] Figure 1 and Figure 2 A power tool 1 according to the invention is shown, which is a pipe press in an exemplary embodiment. Instead of being an embodiment of a pipe press, the power tool 1 can also be implemented as any other cutting or shaping tool. In particular, the power tool 1 according to the invention can also be implemented as a dispensing device for chemicals such as adhesives or sealing compounds. Such a dispensing device can also be called a dispenser.

[0023] like Figure 1 It can be seen that the power tool 1 implemented as a pipe press basically has a housing 2, tool accessories 3 and power supply 4.

[0024] The housing 2 of the power tool 1 is basically cylindrical and includes a front end 2a, a rear end 2b, a left side surface 2c, a right side surface 2d, an upper side 2e, and a lower side 2f. The central portion 2g of the housing 2 serves as a handle to allow the power tool 1 to be held and controlled. Figures 1 to 3 Only the left surface 2c is shown in the image.

[0025] The power source 4 is located at the rear end 2b of the housing 2 of the power tool 1. In this exemplary embodiment, the power source 4 is in the form of a rechargeable battery (also referred to as a power pack or battery). The power source 4, in the form of a rechargeable battery, can be detachably connected to the rear end 2b of the housing 2 of the power tool 1 via an interface 5. Power is supplied to the power tool 1 or its power-consuming devices by means of the rechargeable battery 4.

[0026] In an alternative embodiment of the invention, the power source 4 of the power tool 1 may also be implemented as a cable for detachably connecting the power tool 1 to the mains power source (i.e., an electrical socket).

[0027] Tool fitting 3 for detachably receiving and holding tool 6 is positioned at the front end 2a of housing 2 of power tool 1. In this exemplary embodiment, tool 6, in the form of a deformable tool, is positioned at tool fitting 3. In this exemplary embodiment, deformable tool 6 is implemented as a so-called indenter. The deformable tool 6 implemented as an indenter is essentially used for processing, and particularly deforming, pipelines (i.e., pipes or fittings). During the deformation process, the diameter of the pipeline is reduced essentially by means of the tool implemented as an indenter. The pipeline is not shown in the figures.

[0028] The power switch 7 is located on the lower side 2f of the housing 2 of the power tool 1. The power tool 1 can be started and stopped by means of the power switch 7.

[0029] The driver 8, drive shaft 9, transmission device 10, coupling device 11, threaded spindle driver 12, and linear actuator 13 are substantially located inside the housing 2 of the power tool 1. In this exemplary embodiment, the driver 8 is implemented as a brushless electric motor.

[0030] In this exemplary embodiment, the transmission device 10 is implemented as an eccentric transmission device. According to alternative embodiments, the transmission device may also be implemented in a form other than an eccentric transmission device.

[0031] like Figure 2 and Figure 5 As shown, a driver 8, implemented as a brushless electric motor, is connected via a drive shaft 9 to a transmission device 10, implemented as an eccentric transmission device. Through the connection with the drive shaft 9, the torque generated in the driver 8 is transmitted from the driver 8 to the transmission device 10.

[0032] The speed ratio between the driver 8 and the output shaft 11 can be generated by the transmission device 10.

[0033] Especially Figure 3 As shown, the transmission device 10, implemented as an eccentric transmission device, also substantially includes a drive eccentric member 14, an eccentric gear 15, a ring gear 16, and a compensating coupling 17. The drive eccentric member 14 has a compensating weight 18 (also referred to as a balancing weight or counterweight), which is connected to the driver 8 via a drive shaft 9. A bearing 30 is positioned between the drive eccentric member 14 and the driver 8, see [reference needed]. Figure 5 The eccentric gear 15 includes an aperture 15a for the ball bearing 19. The drive eccentric member 14 is fitted into the ball bearing 19 and thereby connected to the eccentric gear 15 to rotate together with it. The rotation of the drive eccentric member 14 in the rotational direction R also causes the eccentric gear 15 to rotate accordingly in an oscillating motion.

[0034] Furthermore, the eccentric gear 15 is positioned within the ring gear 16. The ring gear 16 is fixedly connected to the interior of the power tool 1's housing 2 in a rotational sense. See also Figure 3 The eccentric gear 15 and the ring gear 16 have involute teeth 20.

[0035] Furthermore, the eccentric gear 15 includes a plurality of orifices 21 arranged in a circular pattern around the drive eccentric member 14. In the exemplary embodiment shown in the figure, the orifices 21 are in the form of eleven through holes. However, there may be more or fewer than eleven through holes. According to an alternative embodiment, the orifices 21 may also be formed as blind holes. The blind holes are arranged such that the corresponding closed ends of the blind holes are arranged opposite to the direction of arrow A and the open ends of the blind holes face the direction of arrow A.

[0036] In this exemplary embodiment, the compensating coupler 17 is implemented as a parallel crank coupler having a connecting element 22. Each of the through holes 21 of the eccentric gear 15 is used to receive the connecting element 22. In this exemplary embodiment, the connecting element 22 is implemented as a connecting pin.

[0037] Therefore, the compensating coupling 17 can be referred to as a parallel crank coupling, or alternatively as a pin or crank coupling.

[0038] Similarly, Figure 3 As can be seen, the free end 22a of each connecting pin 22 protrudes from the through hole 21 of the eccentric gear 15 in the direction of arrow A. The free end 22a of each connecting pin 22 is then connected to the connecting device 11 in such a way that torque can be transmitted from the connecting pin 22 of the compensating connector 17 to the output shaft 11.

[0039] The connecting device 11 has a generally cylindrical shape and includes a sleeve 11a, a piston 11b and a spring element 11c.

[0040] In principle, the connecting device 11 is used here as the output shaft from the transmission device 10 to the threaded spindle driver 12.

[0041] like Figure 4 As can be seen, piston 11b is positioned inside sleeve 11a. Sleeve 11a has a basic cylindrical shape, with a first end 32 and a second end 33. A step is provided between the first end 32 and the second end 33 of the sleeve, and therefore the outer shell of sleeve 11a has a first diameter and a second diameter. Here, the first diameter is larger than the second diameter. Figure 4 As shown, the first diameter precedes the second diameter in the direction of arrow A. The inner diameter of sleeve 11a is constant. Piston 11b also has a basic cylindrical shape, with a first end 34 and a second end 35. At the first end 34, piston 11b has a gear element 36. The second end 35 of piston 11b is connected to threaded spindle driver 12 to rotate together with the threaded spindle driver, thereby enabling the rotational motion of piston 11b to be transmitted to threaded spindle driver 12.

[0042] In the exemplary embodiment shown in the figures, spring element 11c is implemented as a torsion bar spring. Furthermore, the spring element 11c, implemented as a torsion bar spring, is a component of piston 11b or an integral component of the piston. Figure 4 and Figure 5 As shown, spring element 11c is positioned between the first end 34 and the second end 35 of piston 11b. The dimensions of the spring element, implemented as a torsion bar spring, and particularly its diameter, should be selected such that when torque is applied to connecting device 11, spring element 11c can rotate in the direction of rotation R or R' to absorb the torsional force. High torque or torsional force can act on spring element when the threaded spindle drive 12, connected to spring element 11c and rotating therewith, is in its fully extended or fully retracted position.

[0043] A toothed profile 31 for connecting the piston 11b to the sleeve 11a for rotation therewith is included between the outer wall AW of the piston 11b and the inner wall IW of the sleeve 11a. The toothed profile 31 includes a plurality of teeth Z extending in the direction of arrow A on the inner wall IW of the sleeve, and correspondingly arranged teeth Z on the gear element 36 of the piston 11b. In this exemplary embodiment, the cross-sectional area of ​​each tooth Z is in the form of a symmetrical trapezoid, see [reference needed]. Figure 4 However, according to alternative embodiments, the cross-sectional area of ​​tooth Z can actually take on any possible symmetrical or asymmetrical shape.

[0044] By means of the toothed profile 31 between the outer wall AW of piston 11b and the inner wall IW of sleeve 11a, piston 11b is connected to sleeve 11a on the one hand to rotate together with sleeve, and on the other hand, piston 11b can move axially in the direction of arrow A inside sleeve 11a.

[0045] The connecting device 11 is mounted inside the housing 2 of the power tool 1 by means of a main bearing 23 and a secondary bearing 24. The main bearing 23 is positioned on the second diameter of the sleeve 11a, while the secondary bearing 24 is positioned on the first diameter of the sleeve. The main bearing 23 is implemented as a rolling bearing or a ball bearing, while the secondary bearing 24 is implemented as a sliding bearing. According to an alternative exemplary embodiment, both the main bearing 23 and the secondary bearing 24 can be implemented as rolling bearings or sliding bearings. According to an alternative embodiment, only a single bearing may be provided.

[0046] As described above, the connecting device 11 is connected to the compensating connector 17 of the transmission device 10. The connecting device 11 is further connected to the threaded spindle drive 12. The rotational motion of the connecting device 11 can be converted into linear motion by means of the threaded spindle drive 12.

[0047] As can be seen from the figure, the threaded spindle driver 12 is connected to the linear actuator 13.

[0048] By means of the rotational motion of the drive shaft 9 in the rotational direction R about the rotational axis N, the sleeve 11a and the piston 11b also rotate in the rotational direction R about the rotational axis N, thereby causing the piston 11b to be pushed in the direction of arrow A.

[0049] Figure 5 The piston 11b is shown in a first position or in a first state of piston assembly 11, wherein the piston 11b is still in its initial position. The first end 34 of the piston 11b with gear element 36 is still substantially located at the transmission 10. The threaded spindle drive 12 is in the fully retracted position here, and a certain torsional force acts on the spring element in the direction of rotation R.

[0050] If piston 11b moves further in the direction of arrow A, gear element 36 is approximately at the center of sleeve 11a. The axial movement of piston 11b in the direction of arrow A also causes the thrust rod 26 to move in the direction of arrow A. The threaded spindle drive 12 moves out of the fully retracted position, and no torsional force acts on the spring element.

[0051] If piston 11b moves further in the direction of arrow A, the gear element 36 of piston 11b is located at the second end 33 of sleeve 11a. Thrust rod 26 is now pushed to its maximum extent by piston 11b in the direction of arrow A. The threaded spindle drive 12 is in its fully extended position here, and a certain torsional force acts on the spring element in the direction of rotation R'.

[0052] The linear actuator 13 basically includes a compression spring 25 and a push rod 26. Here, the compression spring 25 serves as the return spring for the linear actuator 13.

[0053] A force flow diversion device 27 is provided at the linear actuator 13. With the help of the linear actuator 13 and the force flow diversion device 27, the linear force of the linear actuator 13 is transmitted to the tool accessory 3, so that the tool 6 in the form of a pressure head can move between the open position and the closed position.

[0054] The driver 8, implemented as an electric motor, can rotate at a speed between 10,000 rpm and 30,000 rpm at the maximum extension and retraction speed of the linear actuator 13. In particular, the driver 8 is provided with a speed between 15,000 rpm and 18,000 rpm.

[0055] List of reference numerals

[0056] 1 Power Tools

[0057] 2 shells

[0058] 2a Front end of the shell

[0059] Rear end of 2b housing

[0060] The left side surface of the 2c housing

[0061] The right side surface of the 2D shell

[0062] The upper side of the 2e housing

[0063] 2f lower side of the shell

[0064] 3 Tools and Accessories

[0065] 4 power supplies

[0066] 5 interfaces

[0067] 6 tools

[0068] 7 Enable Switch

[0069] 8 drives

[0070] 9 drive shafts

[0071] 10 Transmission Device

[0072] 11 Connecting Device

[0073] 11a sleeve

[0074] 11b Piston

[0075] 11c spring element

[0076] 12-thread spindle drive

[0077] 13 linear actuators

[0078] 14 drive eccentric components

[0079] 15 eccentric gears

[0080] The orifice in the 15a eccentric gear

[0081] 16 ring gears

[0082] 17 Compensation Connector

[0083] 18 Compensating counterweights

[0084] 19 ball bearings

[0085] 20 Involute teeth

[0086] 21. The orifice in the eccentric gear

[0087] 22 Connecting elements

[0088] 22a Free end on connecting element

[0089] 23 main bearing

[0090] 24 sets of bearings

[0091] 25 compression spring

[0092] 26 thrust rods

[0093] 27. Force flow steering device

[0094] 30 bearing

[0095] 31 Tooth Profile

[0096] The first end of the 32 sleeve

[0097] The second end of the 33 sleeve

[0098] The first end of the 34 piston

[0099] The second end of the 35 piston

[0100] 36 Gear Components

[0101] AW piston outer wall

[0102] The inner wall of the IW sleeve

[0103] Z-shaped tooth profile

Claims

1. A power tool (1), comprising: Driver (8); Transmission device (10); Threaded spindle driver (12); Linear actuator (13), wherein the torque generated by the driver (8) can be transmitted to the linear actuator (13) via the transmission device (10) and the threaded spindle driver (12). A connecting device (11) for converting the rotary motion generated by the transmission device (10) from the transmission device (10) to the threaded spindle driver (12) into linear motion to be transmitted to the threaded spindle driver (12); and At least one spring element (11c) is provided for reducing the torque acting on the connecting device (11). The transmission device (10) includes a drive eccentric member (14), an eccentric gear (15), a ring gear (16), and a compensating connector (17). The eccentric gear (15) includes an orifice for a ball bearing (19). The eccentric gear (15) is positioned in the ring gear (16), which is fixedly connected to the interior of the housing (2) of the power tool (1) in a rotational sense. The connecting device (11) includes a sleeve (11a) and is mounted in the interior of the housing (2) of the power tool (1) by means of a main bearing (23) and a secondary bearing (24). The main bearing (23) is positioned on the second diameter of the sleeve (11a), while the secondary bearing (24) is positioned on the first diameter of the sleeve.

2. The power tool (1) as described in claim 1. Its features are, The connecting device (11) has a piston (11b) for converting the rotational motion generated by the transmission device (10) from the transmission device (10) and the threaded spindle driver (12) into linear motion to be transmitted to the threaded spindle driver (12), wherein a tooth profile (31) for connecting the piston (11b) to the sleeve (11a) to rotate therewith is contained between the sleeve (11a) and the piston (11b), resulting in the piston (11b) being arranged in a manner that allows it to move axially relative to the sleeve (11a) and rotate with the threaded spindle driver (12), and wherein the at least one spring element (11c) is an integral part of the piston (11b).

3. The power tool (1) as described in claim 1 or 2. Its features are, The at least one spring element (11c) is implemented as a torsion bar spring.

4. The power tool (1) as described in claim 1. Its features are, The power tool (1) is a pipe press.

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