Handheld traction and compression device and hydraulic power amplifier

Abstract

The invention relates to a hand-held pulling and pushing device and a hydraulic power amplifier for a hand-held pulling and pushing device for driving drawing and pressing tools. In order to provide a hydraulic power amplifier for an electromechanically driven, hand-held pulling and pushing device and a hand-held pulling and pushing device that can be easily and flexibly adapted to different work processes, the hydraulic power amplifier is provided with a housing body having at least one first working chamber filled with hydraulic fluid and having a connecting section for releasably securing the hydraulic power amplifier to a connecting section of the pulling and pushing device.Furthermore, the hydraulic power amplifier comprises a first hydraulic piston, which is arranged displaceably in the first working chamber between an initial position and an end position and has a first piston surface and a coupling section for connection to a drive element of the pull-and-push device that is adjustable relative to the connection section. Furthermore, the hydraulic power amplifier comprises a second hydraulic piston, which is arranged displaceably in the working chamber at a distance from the first hydraulic piston and has a second piston surface that is larger than the first piston surface, and a mechanical tool connection for the pull-and-push tool.

Description

[0001] The invention relates to a hand-held pulling and pushing device and a hydraulic power amplifier for a hand-held pulling and pushing device for driving pulling and pressing tools.

[0002] Hand-held pulling and pushing devices, i.e. devices that can be used by a single person in a mobile manner, such as hand-held, electric riveting and pressing devices for setting blind rivet elements, such as blind rivets and blind rivet nuts, or for carrying out punching processes and for setting punch rivets, which have a drive unit with an electric motor-driven threaded spindle of a screw drive, are known in a wide variety of designs from the prior art. The screw drive converts a rotary movement of the electric motor into a linear movement of the pulling or pressing tool in a known manner. When carrying out the setting process of a blind rivet element, for example, a pulling mandrel of the blind rivet element is moved axially.

[0003] The handheld pull and push devices described above are used, for example, in automotive workshops for carrying out repair work on vehicle bodies and for maintenance work on pipe or cable connections. Depending on the work to be performed, the pull and push devices may need to drive a wide variety of interchangeable tools, for example, with varying levels of force.

[0004] Known hand-held devices that enable the operation of both drawing and pressing tools have the disadvantage that their application possibilities are limited by the design of the device, in particular the screw drive and / or the drive unit.

[0005] Based on this, the invention is based on the object of providing a hydraulic power amplifier for an electro-mechanically driven, hand-held pulling and pushing device as well as a hand-held pulling and pushing device that can be easily and flexibly adapted to different work processes.

[0006] The invention solves the problem by a hydraulic power amplifier having the features of claim 1 and by a hand-held pulling and pushing device having the features of claim 11. Advantageous further developments of the hydraulic power amplifier are specified in claims 2 to 10.

[0007] The hydraulic power amplifier according to the invention (hereinafter referred to as power amplifier) ​​comprises a housing body having at least one first working chamber filled with hydraulic fluid, for example hydraulic oil, and a connecting section for releasably securing the power amplifier to a connecting section of the tension and compression device. According to the invention, the power amplifier comprises a first hydraulic piston arranged displaceably in the first working chamber between an initial position and an end position, having a first piston surface and a coupling section for connection to a drive element of the tension and compression device that is adjustable relative to the connecting section.In addition, according to the invention, the power amplifier has a second hydraulic piston which is arranged displaceably in the working chamber at a distance from the first hydraulic piston and has a second piston surface which is larger than the first piston surface and a mechanical tool connection for pulling and pushing tools.

[0008] A hydraulic power amplifier is a unit designed to increase the tensile and compressive forces generated by the hand-held pulling and pushing device and to transfer them to a pulling or pushing tool.

[0009] The working chamber is delimited by an inner wall of the housing body as well as by the first piston surface of the first hydraulic piston and the second piston surface of the second hydraulic piston, which preferably faces the first piston surface.

[0010] The design of the housing body with a connecting section allows the force amplifier to be fixed to an electromechanically driven pull and push device, allowing it to be used for operations involving higher pull or push forces. The first hydraulic piston is reliably connected via its coupling section to a drive element adjustable via the electromechanical drive, e.g., a tool holder of the pull and push device.

[0011] The fixed arrangement of the force amplifier on the tension and compression device and the connection of the drive element of the tension and compression device to the first hydraulic piston make it possible to reliably adjust the first hydraulic piston between its initial position and its end position, so that the second hydraulic piston is adjusted accordingly via the pressure generated in the working chamber. Preferably, the second hydraulic piston is adjustable between an initial position associated with the initial position and an end position associated with the end position.

[0012] Because the second piston surface is larger than the first piston surface, the force transmitted from the pull-and-push device to the first hydraulic piston is amplified. The second hydraulic piston can be mechanically connected to a pull-and-push tool via the tool connection, for example, via a positive connection along the longitudinal axis of the housing body, so that the amplified pull-and-push forces are transmitted to the pull-and-push tool. Switching between the use of pull-and-push forces generated by the pull-and-push device and the pull-and-push forces increased by the force amplifier can be easily achieved by disassembling and reassembling the force amplifier.

[0013] In principle, the pressure of the hydraulic fluid is sufficient to transfer the tensile forces from the first hydraulic piston to the second hydraulic piston. According to an advantageous development of the invention, the second hydraulic piston is positively connected to the first hydraulic piston via a connecting element. The connecting element is, for example, detachably connected to the second hydraulic piston or formed integrally on the second hydraulic piston. Preferably, the connecting element is designed such that a positive connection is created between the first and second hydraulic pistons in the longitudinal axis direction of the housing body. Particularly preferably, the second hydraulic piston is connected to the first hydraulic piston via the connecting element in such a way that the positive connection is created when the first hydraulic piston is adjusted from the end position towards the starting position.Such a positive connection ensures easy adjustment of the second hydraulic piston by the first hydraulic piston, both toward the end position and toward the initial position. The positive connection can be designed, for example, in the form of a thread or bayonet lock, so that both tensile and compressive forces of the drive element can be transmitted from the first hydraulic piston to the second hydraulic piston.

[0014] Particularly preferably, the first hydraulic piston has a receptacle for arranging the connecting element. The receptacle is preferably understood to be a cavity of the first hydraulic piston. The receptacle preferably extends with a, for example, circular cross-section in the longitudinal direction of the hydraulic piston. The cross-section of the receptacle is preferably adapted to the shape of the connecting element such that the connecting element can be adjusted within the receptacle when the hydraulic pistons are adjusted. Furthermore, the receptacle is preferably sealed against the ingress of hydraulic fluid. The receptacle advantageously counteracts undesired mutual blocking of the hydraulic pistons when the movement speeds of the hydraulic pistons differ.

[0015] Essential for the function of the power amplifier is a connection between the first hydraulic piston and the drive element of the pulling and pushing device. For this connection, a coupling element can be provided on the first hydraulic piston, for example, which can be connected to a drive element within the pulling or pushing device. According to an advantageous development of the invention, it is provided that the coupling section is designed for connection to a drive element of the pulling and pushing device, designed as a tool holder. The tool holder is usually a component that is arranged in sections on the end face of the pulling and pushing device and is connected to the electromechanical drive, for example via a screw drive, which enables the pulling and pressing tools to be changed easily.The good accessibility required for this makes it particularly easy to connect the first hydraulic piston of the power amplifier to the tool holder, for example, by bringing it into contact with the tool holder. It is also possible to connect them in a form-fitting manner so that the first hydraulic piston is positively connected to the tool holder in both adjustment directions of the hydraulic pistons.

[0016] The connection between the force amplifier and the tension and compression device can, in principle, be designed in any desired manner. According to an advantageous embodiment of the invention, the connecting section of the force amplifier has a thread or locking body for releasably securing it to the connecting section of the tension and compression device, which has a thread or locking body receptacles. A corresponding design of the connecting section enables a secure and easily detachable connection of the force amplifier to the tension and compression device without the need for additional components and / or securing elements. To remove the connection between the force amplifier and the tension and compression device, it is only necessary to unscrew it from the thread or to release the locking connection.

[0017] The hydraulic pistons are arranged relative to one another, for example, in such a way that the hydraulic pistons are adjustable along an axis, for example in the direction of the longitudinal axis of the housing body. According to an advantageous development of the invention, however, it is provided that the hydraulic pistons can be arranged at an angle to one another. The hydraulic pistons are arranged, for example, at an angle, for example between 70° and 180°, preferably 75° and 180°, particularly preferably 80° and 180°. The angle between the hydraulic pistons preferably describes the angle between a longitudinal axis of the first hydraulic piston and a longitudinal axis of the second hydraulic piston. The housing body is particularly preferably designed such that the hydraulic pistons are adjustable in the protruding area between different angular positions, for example 90°, 135°, and 180°. The housing body is preferably designed in at least two parts.The housing body preferably has two housing parts that can be rotated relative to one another by a joint element. The joint element is preferably arranged on the housing body in the region of the working chamber filled with hydraulic fluid, particularly preferably between the hydraulic pistons. The advantageous design of the housing body enables a simple and, if necessary, flexible change in the direction of force due to the flexible or fixed arrangement of the hydraulic pistons at an angle to one another, so that the pulling and pushing device connected to the hydraulic power amplifier can be used particularly easily in different, even narrow, environments, such as hard-to-reach areas of a motor vehicle.

[0018] According to an advantageous development of the invention, the housing body has a second working chamber filled with hydraulic fluid, wherein the second working chamber is formed by two partial working chambers connected by a hydraulic coupling. The partial working chambers are preferably separated from one another, preferably in the longitudinal axis direction of the housing body, by the hydraulic pistons and / or the first working chamber, and are connected to one another via the hydraulic coupling, for example, a line for the hydraulic fluid.

[0019] Particularly preferably, the first hydraulic piston has a third piston surface arranged at a distance from the first piston surface, and the second hydraulic piston has a fourth piston surface arranged at a distance from the second piston surface, wherein the third and fourth piston surfaces are each arranged in one of the partial working chambers of the second working chamber. Preferably, the partial working chambers are delimited by the two hydraulic pistons, in particular the third piston surface or the fourth piston surface, and the inner wall of the housing body. The third piston surface is preferably arranged on the first hydraulic piston facing away from the first piston surface. Preferably, the fourth piston surface is arranged on the second hydraulic piston facing away from the second piston surface.

[0020] Preferably, the piston surfaces of the two hydraulic pistons are each connected to one another via a support element, particularly preferably defining the distance between the piston surfaces of a hydraulic piston. The second working chamber and the advantageous design of the hydraulic pistons enable simple and reliable hydraulic resetting of the second hydraulic piston when the first hydraulic piston is moved from the end position to the starting position. Furthermore, this design of the invention can counteract the risk of cavitation of hydraulic fluid in the first working chamber.

[0021] According to an advantageous development of the invention, the second working chamber is connected to a compensation volume for thermal compensation of the hydraulic fluid. The compensation volume is preferably understood to be a container connected to the second working chamber, for example, via a line. The compensation volume is preferably designed to absorb a portion of the hydraulic fluid located in the second working chamber upon thermal expansion and, particularly preferably, to release it back to the second working chamber. For example, the compensation volume has a third hydraulic piston. The third hydraulic piston is preferably adjustable within the compensation volume for absorbing and / or releasing the hydraulic fluid.Preferably, the compensation volume has a spring element for preloading, in particular spring preloading, the third hydraulic piston in order to automatically release the hydraulic fluid held in the compensation volume to the second working chamber.

[0022] According to an advantageous development of the invention, the tool connection comprises a quick-action coupling. The quick-action coupling describes a mechanical coupling of the tool connection, which is preferably designed such that pulling and pushing tools can be easily and quickly connected to the tool holder. For example, the quick-action coupling is designed in the form of a bayonet lock or a ball lock. The quick-action coupling enables a simple and convenient change of the pulling and pushing tools that can be connected to the power amplifier.

[0023] The invention further solves the problem by a hand-held pulling and pushing device for driving pulling and pressing tools, with a drive unit having a battery-operated electric motor, a screw drive with a threaded spindle connected to the drive unit and rotatably mounted on a housing body, and a threaded nut rotatably mounted on the threaded spindle and non-rotatably mounted on the housing body via a bearing unit, and a coupling unit connected to a tool holder for transmitting tensile and compressive forces resulting from the direction of rotation of the threaded spindle from the threaded nut to the tool holder, wherein the tensile and compressive device is detachably connected to a hydraulic power amplifier according to the invention or a further development described above.

[0024] The hand-held pulling and pushing device according to the invention enables not only the drive of mechanically driven pulling and pressing tools with the maximum force generated by the pulling and pushing device via the power amplifier, but also the drive with forces exceeding this maximum force, wherein, if necessary, it is possible to switch between an original drive by the pulling and pushing device and the increased drive via the power amplifier in a simple manner by connecting or disconnecting the power amplifier to the pulling and pushing device.

[0025] An embodiment of the invention is explained below with reference to the drawings. In the drawings: Fig. 1 in a perspective view, a schematic representation of a hydraulic power amplifier for a hand-held pulling and pushing device; Fig. 2a in a sectional view, a schematic representation of the hydraulic power amplifier of Fig.1 with a first hydraulic piston arranged in an initial position; Fig.2b shows a sectional view of a schematic representation of the hydraulic power amplifier of Fig.1 and 2a with the first hydraulic piston arranged in an end position; Fig.3 in a perspective view, a schematic representation of a pulling and pushing device with a hydraulic power amplifier arranged thereon; Fig.4a in a sectional view, a schematic representation of the pulling and pushing device of Fig. 3with the hydraulic power amplifier arranged thereon with the first hydraulic piston arranged in the starting position; Fig.4b shows a sectional view of a schematic representation of the pulling and pushing device of Fig. 3 and 4a with the hydraulic power amplifier arranged thereon with the first hydraulic piston arranged in the end position and Fig.5 in a perspective view a schematic representation of a further embodiment of the hydraulic power amplifier.

[0026] Figure 1 shows in a sectional view an embodiment of a hydraulic power amplifier 1 with a housing body 2 and a cover 13 sealingly closing the housing body 2.

[0027] Within the housing body 2 are a Figure 2a presented initial situation and one in Figure 2bThe first hydraulic piston 3 and the second hydraulic piston 4 are arranged in a housing body 2. An inner wall 5 of the housing body 2, together with a first piston surface 6 of the first hydraulic piston 3 and a second piston surface 7 of the second hydraulic piston 4 arranged at a distance from the first piston surface 6 and facing the latter, defines a first working chamber 8 which is filled with hydraulic fluid. The second hydraulic piston 4 is arranged within the housing body 2 between a Fig. 2a shown initial position and one assigned to the end position, in Fig. 2b The end position shown can be adjusted. Starting from the position shown in Figure 2a In the initial position shown, the first hydraulic piston 3 is in the Figure 2bshown end position adjustable, wherein the pressure generated during the adjustment by the hydraulic fluid arranged in the working chamber 5 for adjusting the second hydraulic piston 4 from the initial position, which in this position with the second piston surface 7 facing the working chamber 5 partially rests against a shoulder 9 of the base body 4, into the Figure 2b shown end position.

[0028] To reset the second hydraulic piston 4 from the Figure 2 shown end position into the Figure 2bIn the initial position shown, a connecting element 10 is used which positively connects the hydraulic pistons 3, 4 and is arranged at one end on the second hydraulic piston 4 and at the other end is received in a receptacle in the form of a cavity 11 arranged on the first hydraulic piston 3. When the first hydraulic piston 3 is adjusted from the end position to the initial position, the connecting element 10 rests against an inner surface 12 of the cavity 11, so that when the first hydraulic piston 3 is returned from the end position to the initial position, a positive connection between the hydraulic pistons 3, 4 is formed in the direction of a longitudinal axis L of the housing body. Via a tool connection 28, the second hydraulic piston 4 can be mechanically connected to a pull and push tool (not shown), so that the pull and push forces increased by the force amplifier 1 are transmitted to the pull and push tool.

[0029] To connect the power amplifier 1 with a Figure 3 In the tension and compression device 14 shown, the housing body 2 has a connecting section 15 which is designed for detachable connection to a connecting section 16 of the tension and compression device 14, so that the force amplifier 1 can be arranged stationary on the tension and compression device 14.

[0030] The pull-and-push device 14 has a drive unit 18 with an electric motor 17, by means of which a threaded spindle 19 of a screw drive 20 arranged in a housing body 27 can be driven. In addition to the threaded spindle 19, the screw drive 20 also has a threaded nut 21 arranged on the threaded spindle 19, which is mounted in a rotationally fixed manner on the housing body 27. The threaded nut 21 serves to drive a tool holder designed as a piston rod 22, which is adjustably mounted in the longitudinal axis direction of the threaded spindle 19, so that by means of the pull-and-push device 14, via the piston rod 22 as the drive element, the first hydraulic piston 3 can be adjusted in the direction of the power amplifier 1. The first hydraulic piston 3 has a coupling section 24 on an end face 23 facing the piston rod 22, so that movements of the piston rod 22 are reliably transmitted to the first hydraulic piston 6.The piston rod 22 is connected to the threaded nut 21 via a detachably connected coupling unit 25, which, at its end opposite the piston rod 22, rests against an end face 26 of the threaded nut 21 facing away from the piston rod 22. A bearing unit 38, which is attached to the coupling unit 25, serves to secure the threaded nut 21 against rotation on the housing body 27.

[0031] For the Figure 5 In the hydraulic booster 1a shown, which represents a further embodiment of the hydraulic booster 1, the same reference numerals are used for the same components. The hydraulic booster 1a differs from the booster according to Fig. 1 to 4bdue to the missing connecting element 15, a second working chamber 29 and an alternative design of the hydraulic pistons 3a, 4a. The first hydraulic piston 3a has a third piston surface 30 arranged at a distance from the first piston surface 6 and the second hydraulic piston 7 has a fourth piston surface 31 arranged at a distance from the second piston surface 7. The second working chamber 29 is formed by two partial working chambers 32, which are each delimited by the third piston surface 30 or the fourth piston surface 31, and the inner wall 5 of the housing body 2a. The partial working chambers 32 are separated from one another in the longitudinal axis direction of the housing body 2a by the hydraulic pistons 3a, 4a and the first working chamber 8 and are connected to one another via a hydraulic coupling in the form of a line 33 for the hydraulic fluid.Furthermore, the piston surfaces 6, 7, 30, 31 of the two hydraulic pistons 3a, 4a are each connected to one another via a support element 34 that defines the distance between the piston surfaces 6, 7, 30, 31 of a hydraulic piston 3a, 4a. The second working chamber 29 is further connected to a compensation volume 35 for thermal compensation of the hydraulic fluid. The compensation volume 35 has a spring element 36 for spring preloading a third hydraulic piston 37 arranged on the compensation volume 35.

[0032] The hydraulic power amplifier 1 enables pulling and pushing tools to be driven with increased pressing force in a simple and reliable manner by means of the hand-held pulling and pushing device 14, whereby the pulling and pushing device 14 can be used flexibly for various work processes.

[0033] All features explained in connection with individual embodiments of the invention can be provided in different combinations for the hydraulic power amplifier or the hand-held pulling and pushing device in order to realize their advantageous effects, even if these have been described for different embodiments. List of reference symbols

[0034] 1Hydraulic power amplifier 2Housing body 3First hydraulic piston 4Second hydraulic piston 5Inner wall 6First piston surface 7Second piston surface 8First working chamber 9Shoulder 10Connecting element 11Receptacle (cavity) 12Inner surface 13Cover 14Pull / push device 15Connecting section 16Connecting section (pull and push device) 17Electric motor 18Drive unit 19Threaded spindle 20Screw drive 21Threaded nut 22Piston rod; Tool holder (drive element) 23End face (first hydraulic piston) 24Coupling section (first hydraulic piston) 25Coupling unit 26End face (coupling unit) 27Housing body (pull and push device) 28Tool connection 29Second working chamber 30Third piston surface 31Fourth piston surface 32Partial working chamber 33Hydraulic coupling (line) 34Support element 35Compensation volume 36Spring element 37Third hydraulic piston LLongitudinal axis of the housing body (power amplifier)

Claims

1. A hand-held pulling and pushing device for driving pulling and pressing tools, comprising - a drive unit (18) having a battery-operated electric motor (17), - a screw drive (20) with a threaded spindle (19) connected to the drive unit (17) and rotatably mounted on a housing body (27), and a threaded nut (21) rotatably mounted on the threaded spindle (19) and non-rotatably mounted on the housing body (28) via a bearing unit (38), and - a coupling unit (25) connected to a tool holder (22) for transmitting pulling and pushing forces resulting from the direction of rotation of the threaded spindle (19) from the threaded nut (21) to the tool holder (22), characterized bya hydraulic power amplifier (1) detachably connected to the tension and compression device (14), with - a housing body (2) having at least one first working chamber (8) filled with hydraulic fluid, with a connecting section (15) for detachably securing the power amplifier (1) to a connecting section (16) of the tension and compression device (14), - a first hydraulic piston (3) arranged displaceably in the first working chamber (8) between an initial position and an end position, having - a first piston surface (6) and - a coupling section (25) for connection to a drive element (22) of the tension and compression device (14) that is adjustable relative to the connecting section (16), and - a second hydraulic piston (4) arranged displaceably in the first working chamber (8) at a distance from the first hydraulic piston (3), having - a larger piston surface than the first piston surface (6),second piston surface (7) and - a mechanical tool connection (28) for pulling and pushing tools., 2. Hand-held pulling and pushing device according to claim 1, characterized in that the second hydraulic piston (4) is positively connected to the first hydraulic piston (3) via a connecting element (10).

3. Hand-held pulling and pushing device according to claim 2, characterized in that the first hydraulic piston (3) has a receptacle (11) for arranging the connecting element (10).

4. Hand-held pulling and pushing device according to at least one of the preceding claims, characterized in that the coupling section (25) is designed for connection to a drive element of the pulling and pushing device (14) designed as a tool holder (22).

5. Hand-held pulling and pushing device according to at least one of the preceding claims, characterized in thatthe connecting section (15) has a thread or locking body for releasably securing it to the connecting section (16) of the pulling and pushing device (14) which has a thread or locking body receptacles.

6. Hand-held pulling and pushing device according to claim 1, characterized in that the hydraulic pistons can be arranged at an angle to each other.

7. Hand-held pulling and pushing device according to at least one of the preceding claims, characterized in that the housing body (2a) has a second working chamber (29) filled with hydraulic fluid, wherein the second working chamber (29) is formed by two partial working chambers (32) connected by means of a hydraulic coupling (33).

8. Hand-held pulling and pushing device according to claim 7, characterized in thatthe first hydraulic piston (2a) has a third piston surface (30) arranged at a distance from the first piston surface (6) and the second hydraulic piston (4a) has a fourth piston surface (31) arranged at a distance from the second piston surface (7), wherein the third and fourth piston surfaces (30, 31) are each arranged in one of the partial working spaces (32) of the second working space (29).

9. Hand-held pulling and pushing device according to claim 7, characterized in that the second working chamber (29) is connected to a compensation volume (35) for thermal compensation of the hydraulic fluid.

10. Hand-held pulling and pushing device according to at least one of the preceding claims, characterized in that the tool connection (28) has a quick coupling.

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