Pressure generator for a pulling or pressing device as well as pulling or pressing device

Abstract

Pressure generator (1) for a hydraulic tool, in particular for a pulling and / or pressing device, comprising a pneumatic piston (13) coupled to a hydraulic piston (18), wherein the pneumatic piston (13) is oscillatively movable by means of a control device, so that pressure can be generated in a hydraulic section (20) by oscillating movement of the hydraulic piston (18), and wherein the hydraulic section (20) has a quick-release coupling (8) with a hydraulic line for a hydraulic tool, wherein the hydraulic section (20) has a relief valve (21) which can be actuated by the control device and / or by an actuating device (2) such that the relief valve (21) opens in a non-actuated position, characterized in that the relief valve (21) is connected to a safety actuating device (7) which must be actuated.to generate pressure in the hydraulic area (20) by means of the actuating device (2).

Description

Field of invention

[0001] The invention relates to a pressure generator for tool applications that require the generation of high forces by means of hydraulic working elements, such as a pulling or pressing device. In particular, the invention relates to a pressure generator designed as a handheld device, which can be coupled with various riveting tool adapters. Background of the invention

[0002] Hydraulically operated setting tools are well-known. These include, for example, riveting tools with a pressing device for riveting conventional rivets. There are also riveting tools with a pulling device for setting blind rivets, blind rivet nuts, etc.

[0003] Pneumatic hand riveters are well-known in practice. These typically feature a pneumatic piston coupled to a hydraulic piston. The gear ratio between the pneumatic and hydraulic pistons allows for higher pressure to be generated in the hydraulic section than is applied to the pneumatic section of the tool via the compressed air connection. Nevertheless, the pulling force of known hand riveters is limited and often insufficient for processing even modern, high-strength rivets. Furthermore, these hand riveters are generally quite unwieldy, making it difficult to reach hard-to-access areas, such as between the body panels of a vehicle.

[0004] Riveting tools connected to a stationary pressure generator via a high-pressure hydraulic hose are also known from practical experience. While the actual riveting tool is often more compact with such tools, they are complex and, in particular, it is difficult to replace a hydraulic riveting tool connected to the stationary pressure generator with another.

[0005] Document EP 1 423 614 B1 shows a print translator.

[0006] Document DE 10 2010 000 545 A1 concerns a hydraulic pressing device for radially pressing workpieces such as fittings onto pipes.

[0007] Document JP H11-245 177 A shows a hydropneumatic tool.

[0008] Document EP 0 117 243 B1 also shows a hand-operated pneumatic hydraulic tool.

[0009] Document EP 0 999 906 B1 shows a pneumatic-hydraulic riveting tool.

[0010] Document US 2 807 021 A shows a compressed air motor. Object of the invention

[0011] In contrast, the invention is based on the objective of reducing the aforementioned disadvantages of the prior art.

[0012] In particular, an object of the invention is to provide an easy-to-handle pressure generator by means of which a hydraulic pulling or pressing device, in particular a riveting device, can be actuated, whereby a high tensile force or pressing force can be achieved due to high pressure. Summary of the invention

[0013] The object of the invention is already solved by a pressure generator for a hydraulic tool, in particular for a pulling and / or pressing device according to one of the independent claims.

[0014] Preferred forms of training and further education can be found in the respective sub-requirements.

[0015] The invention relates to a pressure generator for a hydraulic tool. It is a hydraulically actuated device by means of which, for example, pressure can be applied to a component or a component can be pulled.

[0016] In particular, the invention relates to all types of riveting devices, such as those for conventional rivets, which are pressed together with a pressing device, and for blind rivets, in the processing of which a pin is pulled by means of a pulling device until it breaks off after a rivet has been formed. Blind rivets can also be set with a suitable adapter.

[0017] The hydraulic pressure generator according to the invention can also be used for other hydraulically operated tools such as spreading devices, cartridges for dispensing adhesive or sealant, pliers, in particular for cutting cables, etc.

[0018] The pressure generator includes a pneumatic piston which can be operated via compressed air.

[0019] The pneumatic piston is coupled to a hydraulic piston. The achievable pressure in the hydraulic system is determined by the transmission ratio between the hydraulic and pneumatic pistons.

[0020] Preferably, the transmission ratio is greater than 1:50, and in particular a transmission ratio of 1:100 is provided. The transmission ratio can be as high as 1:150. This allows a pressure of 800 bar to be generated in the hydraulic system with an applied air pressure of 8 bar.

[0021] The pneumatic piston is oscillating via a control device, such that pressure can be generated by the oscillating movement of the hydraulic piston within the hydraulic system. The pressure generator thus functions as a hydraulic pump, which allows a sufficient quantity of hydraulic fluid to be supplied despite the small working space of the hydraulic piston (due to the high gear ratio) in order to move pulling or pressing devices at an appropriate speed.

[0022] Furthermore, the hydraulic section includes a quick-release coupling with a hydraulic line for a pulling or pressing device. The pressure generator is thus decoupled from the actual pulling or pressing device. This device can be connected to the hydraulic section via a quick-release coupling. This allows for particularly easy tool changes. Preferably, the quick-release coupling also provides a rigid mechanical connection.

[0023] Pressure generator and pulling or pressing device can be connected together and used as a handheld device.

[0024] In an alternative embodiment of the invention, it is also conceivable to operate the pressure generator in a stationary manner, i.e., the pulling or pressing device is connected to a pulling or pressing device via a hydraulic line which has a quick coupling.

[0025] In a further development of the invention, the control device comprises a piston control.

[0026] In particular, a pilot control valve is used which can be actuated via the pneumatic piston, especially moved into a closed position.

[0027] Unlike conventional slot controls or reversing devices integrated into the pneumatic piston, this method allows for a relatively large stroke. Furthermore, compared to reversing devices integrated into the piston, the weight of the pneumatic piston is reduced and its reliability is increased.

[0028] Preferably, part of the pilot control valve extends into the working chamber of the pneumatic piston. When the piston retracts, the piston head rests on the pilot control valve and closes it. This allows pressure to build up in the working chamber of the pneumatic piston, which pushes the piston forward.

[0029] When a control bore is passed over, air flows from the working chamber to the pilot control valve and opens it, thereby releasing the compressed air in the working chamber of the pneumatic piston and resetting the piston, which works against a spring, for example, until it closes the pilot control valve again.

[0030] The stroke of the pneumatic piston is preferably between 5 and 20 mm. Furthermore, the piston preferably operates at a frequency of 5 to 20 Hz.

[0031] According to one aspect of the invention, the hydraulic section includes a relief valve. This relief valve serves to allow the hydraulic fluid to flow back when the valve is not actuated.

[0032] Furthermore, the pressure relief valve, which is preferably configured as a three-way or two-way valve, can also perform safety-related functions. According to one aspect of the invention, the pressure relief valve must be closed by means of an actuating device before each actuation of the pressure generator in order to build up pressure.

[0033] This means the tool can only be operated with two hands. For this purpose, the pressure relief valve is controlled via an actuator on the pressure generator in such a way that it opens immediately when the actuator is released. This ensures that the hydraulic system is depressurized immediately upon release of the actuator.

[0034] In a preferred embodiment of the invention, a hydraulic fluid reservoir is arranged in a chamber that extends at least partially around the hydraulic area. An elastomer membrane can be used as the chamber. This embodiment of the invention allows the volume around the significantly smaller hydraulic piston to be used for storing hydraulic fluid, thus enabling a more compact design of the tool.

[0035] In another preferred embodiment of the invention, the quick coupling has a self-closing valve for hydraulic fluid.

[0036] Preferably, both the pressure generator and the pulling or pressing device connected to the pressure generator have a self-closing valve. This allows the two components of the tool to be easily connected, creating a hydraulic connection between them.

[0037] Preferably, an actuating device is attached to the pressure generator itself to operate the pulling or pressing device. The pressure generator can thus be used as a handheld device and forms a single unit with the attached pulling or pressing device.

[0038] The invention further relates to a pressure generator for a pulling and / or pressing device, which comprises an oscillating pneumatic piston, over which a hydraulic piston connected to the pneumatic piston is moved in an oscillating manner and thus generates a high pressure in a hydraulic area as a hydraulic pump.

[0039] According to the invention, a pilot control valve in a working chamber of the pneumatic piston can be actuated by resetting the pneumatic piston, in particular by moving it into a closed position.

[0040] For this purpose, at least part of the pilot control valve extends into the working chamber of the pneumatic piston, or it is also conceivable that the pneumatic piston has an extension, for example in the form of a mandrel, to actuate the pilot control valve arranged in a recess.

[0041] As described above, this type of reversing provides reliable reversing with a high possible stroke.

[0042] The invention further relates to a pulling or pressing tool, in particular designed as a riveting tool, punching tool or cartridge press, which comprises at least a hydraulic section that can be connected to a pressure generator described above by means of a quick coupling.

[0043] The hydraulic section includes a hydraulic piston that operates the pulling or pressing tool.

[0044] To achieve a high tensile force or a high force during pressing, this hydraulic piston has a larger diameter than the hydraulic piston which builds up the pressure in the pressure generator to actuate the tool.

[0045] Using such a pulling or pressing device, it is possible to generate forces of more than 100 kN. The quick-release coupling provides a multifunctional tool.

[0046] The invention thus makes it possible to provide a tool system with a pressure generator described above, which comprises a plurality of different pulling and / or pressing devices that can be connected to the pressure generator by means of a quick coupling. Description of the drawings

[0047] The invention will be described below with reference to the drawings. Fig. 1 to Fig. 16 will be explained in more detail using schematically illustrated examples.

[0048] Fig. Figure 1 shows a perspective view of a printing press.

[0049] The pressure generator 1 comprises a housing 5, which in this embodiment is designed in three parts and includes a head piece, a middle piece and an end piece.

[0050] An actuating device 2 is attached to the end piece of the housing 5, by means of which the pressure generator is put into operation. The actuating device 2 is arranged below a handle 4.

[0051] Behind the actuating device 2 is a pressure regulator 3, which allows the pressure in the pneumatic system and thus also the pressure in the hydraulic system to be adjusted. The pressure generator 1 can be connected to compressed air via a compressed air connection 6.

[0052] At the front of the pressure generator 1 is a quick-release coupling 8, which has a self-closing hydraulic valve 9 in the center. A pulling or pressing device (not shown) can be attached to the pressure generator 1 by means of the quick-release coupling 8.

[0053] In this case, hydraulic fluid can be directed into the pulling or pressing device via the self-closing hydraulic valve 9.

[0054] A safety actuating device 7 is arranged on the front part of the housing.

[0055] Depending on the design variant, a device with two-hand operation can be provided via the safety operating device 7, such that both the safety operating device 7 and the operating device 2 must be actuated to generate pressure.

[0056] In an alternative embodiment, the safety actuating device 7 must be moved into the active position shown here before the actuating device 2 is actuated. After the actuating device 2 has been released at the end of a riveting operation, the safety actuating device 7 folds forward, and the next pulling or pressing operation can only be carried out when the safety actuating device 7 is folded back into the position shown here.

[0057] On the side of the housing 5 there is another screw 10, above which the hydraulic area can be opened and hydraulic fluid can be refilled.

[0058] Fig. 2 shows a sectional view of the in Fig. 1. The printer shown in Figure 1, which will be used to explain the function of the printer in more detail.

[0059] The pneumatic section, i.e. the section in which compressed air is located in the device, is connected to a compressed air source, such as a compressor, via the compressed air connection 6.

[0060] The pressure regulator 3 is designed as a so-called upstream pressure regulator. The valve seat 63 is adjusted in its position via a threaded drive of the pressure regulator 3. The piston 64, which is pre-tensioned downwards by a spring, is centrally supplied with compressed air. By adjusting the valve seat 63, the spring force changes and thus the set working pressure. The air volume is regulated via the flow control valve 61.

[0061] The function of an upstream pressure regulator is otherwise known to the expert and requires no further explanation.

[0062] Compressed air can be directed via channel 65 into the working chamber 14 of the pneumatic piston 13 via the switching valve 12.

[0063] When actuated, in this embodiment when the actuating device 2 and the switching valve 12 coupled to it by means of the pin 11 are pressed down, compressed air flows through the channel 65 into the working chamber 14 of the pneumatic piston 13. The pneumatic piston 13 is coupled to the smaller hydraulic piston 18, or the pneumatic piston 13 and hydraulic piston 18 can form a single component. The inflow of compressed air initially moves the pneumatic piston 13 to the left from the position shown here.

[0064] Upon exceeding the control bore 62, compressed air from the working chamber 14 flows through the channel 16 to the pilot control valve 54, which controls the pneumatic piston 13. The compressed air flowing in through the channel 16 then moves a piston 66 of the pilot control valve 54 to the left, opening the valve. Compressed air from the working chamber 14 of the pneumatic piston 13 can now flow into the atmosphere via the exhaust chamber 58 and a silencer (not shown).

[0065] As the pressure in working chamber 14 now drops, the pneumatic piston 13 is moved to the right by the spring 17 until the piston 13 rests on the pilot control valve 54 and closes it again. Now the working chamber 14 is closed again, and the compressed air flowing in through channel 15 can build up working pressure again.

[0066] The use of the pilot control valve 54, which is arranged axially in a row with both the pneumatic piston 13 and the hydraulic piston 18, provides reliable control with a large stroke and thus high performance.

[0067] The system operates as a hydraulic pump, meaning that the pneumatic piston 13, and consequently the hydraulic piston 18, is moved in an oscillating motion. Therefore, hydraulic fluid can be continuously pumped, and a small working volume of the hydraulic piston 18 is sufficient to provide an adequate quantity of hydraulic fluid.

[0068] To function as a pump, the hydraulic section includes a pressure valve 59 and a suction valve 19, through which fluid can only flow in the direction of the hydraulic valve 9, to which the pulling or pressing device is connected. The design of the pressure valve 59, which opens during each pumping operation in which the piston is moved to the left, and of the suction valve 19, which allows hydraulic fluid to flow into the working chamber of the hydraulic piston when the piston is reset, is known to those skilled in the art and requires no further explanation.

[0069] The hydraulic valve 9 consists of a sleeve 9a and a plug 9b, which closes the valve by means of spring force when no pulling or pressing device is connected.

[0070] The hydraulic valve 9 is part of the quick coupling 8, which is connected to the hydraulic area 20 by means of a sealing-enclosing connector 57.

[0071] The quick coupling 8 can be released by turning and is locked in the attached state via the locking lever 23 to ensure that the coupling is not accidentally released when pressure is applied.

[0072] The housing 47 of the quick coupling 8 is preferably screwed to the housing of the pressure generator or to the front housing part.

[0073] The pressure generator further comprises a relief valve 21. In this embodiment, it is a three-way two-way valve. In its normal state, the relief valve 21 is opened via channel 22 when compressed air is applied. For this purpose, the compressed air flows via channel 22 into a working chamber and pushes down the relief piston 60.

[0074] Since the hydraulic fluid from hydraulic area 20 now flows back continuously, no pressure can build up.

[0075] Actuating the actuating device 2 closes the channel 22 and closes the relief valve 21 due to spring preload. Consequently, pressure can build up in the hydraulic section 20.

[0076] When the operator releases the actuating device 2, compressed air flows through the channel 22 and opens the relief valve 21, so that the hydraulic area becomes depressurized immediately after releasing the actuating device 2.

[0077] In this embodiment, a safety actuating device 7 is also provided, which is arranged as an eccentric above the relief piston 60.

[0078] Pressure build-up is only possible in the position of the safety actuating device 7 shown here, because when the safety actuating device is flipped, the eccentric holds the relief piston 60 in the open position and thus prevents the relief valve 21 from closing.

[0079] The safety actuating device 7 can be designed such that it automatically moves into an open position of the relief valve, for example by means of a spring. Before each new actuation of the actuating device 2, the safety actuating device 7 must then be returned to the position shown here, in which it initially remains because it is held in place by the spring preload of the relief valve 21. After actuation of the actuating device, the safety actuating device 7 folds back into the inactive position.

[0080] Depending on the design variant, a two-hand control can also be provided via the safety operating device 7, in which case it must be continuously operated in order to build up pressure at all (not shown).

[0081] Fig. Figure 3 shows a view of the pressure generator 1 from the front, looking at the quick-release coupling 8. The quick-release coupling 8 comprises engagement elements which can be moved radially inwards by means of the cam ring 25 to lock a corresponding coupling element. In the locked state, the cam ring 25 can be secured in the locked position by means of the locking lever 23. The cam ring 25 can therefore only be rotated back once the locking lever 23 is released.

[0082] Fig. 4 shows a section view along line BB from Fig. 1. The engagement elements 24 can be seen in the form of balls, which can be moved inwards by means of the cam of the cam ring 25 when the latter is rotated.

[0083] Fig. Figure 5 shows a first pressing device 26, which can be connected to a pressure generator described above. For this purpose, the pressing device 26 includes a quick-release coupling 27, which has a groove in which the connection associated with Fig. 3 and Fig. The 4 described intervention elements can intervene.

[0084] At its front end, the pressing device 26 includes a head piece 28 with a rivet receptacle.

[0085] Fig. Figure 6 shows a section view along line AA. Fig. 5. The self-closing hydraulic valve 29 is visible. The press device also includes a piston 30, which is reset by means of a spring 31. When hydraulic fluid is introduced, the piston moves forward and initiates the riveting process via the head 28.

[0086] The pressing device 26 further has a groove 32 on its edge, which is used to attach the Fig. 7 in a perspective view, bracket 33 is provided.

[0087] The bracket 33 is attached to the pressing device (26 in) by means of a locking pin 34. Fig. 5 and Fig. 6) attached. The bracket has a rivet holder 35 in which the second part of the rivet is inserted in order to carry out a setting process with the pressing device to which the bracket 33 is attached, in which a two-part conventional rivet is processed.

[0088] Fig. Figure 8 shows a perspective view of a blind riveting device 36, which can also be attached to a pressure generator described above by means of the quick coupling 27.

[0089] The blind riveting device 36 comprises a pulling device 37 with a head piece 38 into which the rivet pin of a blind rivet can be inserted.

[0090] The pulling device 37 is attached to a holder 40, which includes the quick-release coupling 27, by means of a swivel bearing 39. This allows the pulling device 37 to be swivelled at least 90° around the holder 40 in order to reach difficult-to-access areas.

[0091] Fig. Figure 9 shows the blind riveting device 36 with the head 38 in a front view. It can be seen that the diameter of the pulling device 37 essentially corresponds to the diameter of the head 38, which is usually designed to be screwed on. The pulling device and head are thus very compact.

[0092] Fig. Figure 10 shows a sectional view of the blind riveting device 36 along line EE. Fig. 9.

[0093] The pulling device 37 includes a piston 42. At the rear end of the pulling device is a removable container 43 in which broken rivet pins are collected. The pivot bearing 39 includes a detent mechanism by which the pulling device 37 can be engaged in defined positions or locked via a pin when it is pivoted around the holder 40. Also visible is the quick-release coupling 27 with a self-closing valve for hydraulic fluid.

[0094] Fig. Figure 11 shows another sectional view of a pulling device 36. In this sectional view, the claws of a gripping device 44 for grasping the rivet pin are clearly visible.

[0095] A rotary union 45 can also be seen in the area of ​​the swivel bearing 39. Hydraulic fluid is supplied to the pulling device via the rotary union.

[0096] The quick coupling 27 includes a self-closing hydraulic valve 29, which is located in Fig. 12 is shown in detail.

[0097] The self-closing hydraulic valve is arranged in a housing 47 of the quick-release coupling and is sealed at the end face by the seal 46. When coupled to the quick-release coupling of the pressure generator (8 in Fig. 2) The sleeve 55 is pressed to the left, whereby a corresponding sleeve of the quick-release mechanism of the printing unit (9a in Fig. 2) penetrates the housing 47 and is sealed via the seal 46. The sleeve 55 is held under preload by the spring 48. A central pin 56 now simultaneously presses the plug of the hydraulic valve of the pressure generator (9b in Fig. 2) inwards, so that a channel is created between the hydraulic valves through which hydraulic fluid can flow.

[0098] Fig. Figure 13 shows an improved rivet insert 49, which can be used, for example, in conjunction with the previously described pressing device. The rivet insert 49 is designed for use with known rivet heads available on the market. For this purpose, a known head piece 51 is attached by means of a clamping sleeve 52, which is pulled onto a clamping cone 53. The components are inserted into the housing 50 for this purpose.

[0099] Fig. Figure 14 shows a sectional view along line BB in Fig. 13. Particularly noticeable is the slotted clamping sleeve 52 at the bottom, which is spread open at the bottom by the clamping cone 53 and thus provides a force-fit fastening of the head piece 51.

[0100] Unlike conventional rivet head fittings, this fitting has no threads for securing the head. With conventional fittings that do have threads, the screw connection can loosen. During pressing, the threads can then be damaged, which cannot happen with this fitting.

[0101] Fig. Figure 15 shows a further detailed illustration of the principle. The clamping cone 53 is visible, which in the cross-sectional view has an approximately claw-shaped profile. Due to the clamping sleeve 52, these claws fit snugly and securely against the head piece 51.

[0102] Referring to Fig. Section 16 describes a further, alternative embodiment of the invention in which the previously described pressure generator is operated in a stationary manner. A handle 80 with a quick-release coupling 81 is shown, which corresponds to the quick-release coupling of the pressure generator and to which the previously described pressing and pulling tools can be connected.

[0103] The handle 80 has an actuating device 32 by means of which a pulling or pressing process can be set up.

[0104] The handle 80 is connected via a hydraulic line 83. This is preferably connected to the pressure generator by means of a quick coupling (not shown).

[0105] Furthermore, the handle includes the pneumatic control lines 84 and 85, which are preferably also connected to a correspondingly modified pressure generator by means of a quick coupling and via which the latter is controlled according to the function of the actuating device 2. Fig. 2 can be controlled.

[0106] The use of such a handle makes it possible for the hand tool, which is used, for example, to set rivets, to be even more compact.

[0107] The invention makes possible in particular very compact riveting and pressing tools, through which a very high tensile force can be exerted. Reference symbol list 1 printer 2 Actuating device 3 pressure regulators 4 handles 5 cases 6 compressed air connection 7 Safety operating device 8 quick couplings 9 Hydraulic valve 9a Sleeve 9b Plug 10 screws 11 pen 12 switching valve 13 pneumatic pistons 14 workroom 15 Channel 16-channel 17 spring 18 hydraulic pistons 19 Suction valve 20 Hydraulic area 21 Relief valve Channel 22 23 locking levers 24 Interlocking element 25 Scenery ring 26 Pressing device 27 Quick coupling 28 Headpiece 29 Hydraulic valve 30 pistons 31 spring 32 Nut 33 rivet brackets 34 locking pins 35 rivet holders 36 Blind riveting device 37 Towing device 38 Headpiece 39 Swivel bearings 40 holders 41 Locking mechanism 42 pistons 43 containers 44 Gripping device 45 Rotary feedthrough 46 Seal 47 cases 48 springs 49 rivet insert 50 cases 51 Headpiece 52 Tension sleeve 53 Spreading cone 54 Pilot control valve 55 Sleeve 56 pens 57 Connector 58 Exhaust chamber 59 Pressure valve 60 relief pistons 61 Flow control valve 62 Control bore 63 Valve seat 64 pistons 65 Channel 66 pistons 80 Handle 81 Quick coupling 82 Actuating device 83 Hydraulic connection 84 Pneumatic control line 85 Pneumatic control line

Claims

[1] Pressure generator (1) for a hydraulic tool, in particular for a pulling and / or pressing device, comprising a pneumatic piston (13) coupled to a hydraulic piston (18), wherein the pneumatic piston (13) is oscillatively movable by means of a control device, so that pressure can be generated in a hydraulic section (20) by oscillating movement of the hydraulic piston (18), and wherein the hydraulic section (20) has a quick coupling (8) with a hydraulic line for a hydraulic tool, wherein the hydraulic section (20) has a relief valve (21) which can be actuated by the control device and / or by an actuating device (2) such that the relief valve (21) opens in a non-actuated position, characterized by, that the relief valve (21) is connected to a safety actuating device (7) which must be actuated in order to generate pressure in the hydraulic area (20) by means of the actuating device (2). [2] Pressure generator (1) for a hydraulic tool according to the preceding claim, characterized by that the control device includes a piston control. [3] Pressure generator (1) for a hydraulic tool according to the preceding claim, characterized by , that a pilot control valve (54) can be moved into a closed position via the pneumatic piston (13). [4] Pressure generator (1) for a hydraulic tool according to one of the preceding claims, characterized by , that the relief valve (21) is connected to the control unit and / or the actuating unit via a pneumatic line. [5] Pressure generator (1) for a hydraulic tool according to one of the preceding claims, characterized by, that a hydraulic fluid reservoir is arranged in a chamber which extends at least partially around the hydraulic piston (18). [6] Pressure generator (1) for a hydraulic tool according to one of the preceding claims, characterized by , that the quick coupling (8) has a self-closing valve (9) for hydraulic fluid. [7] Pressure generator (1) for a hydraulic tool according to one of the preceding claims, characterized by , that the print generator (1) has an actuating device (2). [8] Pressure generator (1) for a hydraulic tool according to one of the preceding claims, characterized by , that the quick coupling (8) has engagement elements (24) which are radially movable in the direction of a central axis by means of a cam guide. [9] Pressure generator (1) for a hydraulic tool, in particular according to one of the preceding claims, comprising a pneumatic piston (13) coupled to a hydraulic piston (18), wherein the pneumatic piston (13) is oscillatively movable by means of a control device, so that pressure can be generated in a hydraulic area (20) by oscillating movement of the hydraulic piston (18), wherein a pilot control valve (54) in a working chamber (14) of the pneumatic piston (13) can be actuated, in particular moved into a closed position, by resetting the pneumatic piston (13), and wherein the pilot control valve (54), which is not integrated into the pneumatic piston (13), is connected to the working chamber (14) via a channel which includes a control bore (62), wherein compressed air flows from the channel (16) to the pilot control valve (54) when the control bore (62) is exceeded. [10] Pulling or pressing tool (36), in particular riveting tool, punching tool or cartridge press, comprising at least one hydraulic section with a hydraulic piston (42) which is connected to a pressure generator (1) according to one of the preceding claims by means of a quick coupling (27). [11] Tool system comprising a pressure generator (1) according to one of the preceding claims and a plurality of different pulling and / or pressing devices which can be connected to the pressure generator (1) by means of a quick coupling (27).

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