EP1084798B1 - Hydraulic press tool - Google Patents

Abstract

The device (1) has a hydraulic piston sliding in a hydraulic cylinder (8) and having a piston head (5) and a piston shaft (16). The piston shaft is connected to a tool support (10), which forms part of an exchangeable device head (9). An exchangeable device head has a piston shaft with a re-adjusting spring (22). The piston shaft and head can be separated from each other.

Description

The invention relates to a hydraulic hand pressure device according to the features of the preamble of claim 1.

Such a hand press device is, for example, from the DE-A1 19716 804 known. This shows a hand press with a screwed to the tool carrier of a replaceable head device piston skirt, which latter is formed integrally with the hydraulically actuated piston head. Next is the state of the art on the DE 43 15 157 A to refer. From this, a hydraulic hand pressure device according to the features of the preamble of claim 1 is known.

Based on the cited prior art, the invention has the object to design the known hydraulic hand press device with regard to a simplification of the head change device in an advantageous manner.

This object is achieved in the subject matter of claim 1, with it being turned off is that an exchange device head each having a piston skirt with return spring. Contrary to the known state of the art, in the embodiment according to the invention the piston skirt is assigned to the device head. The displaceably arranged in the device head tool carrier is by the further arranged return spring after removal of the device head of the hand press always in a basic position, ie in one Held open position, which corresponds to the open position of the tool carrier in the hand pressing device associated position of the device head of the basic position, ie return position of the hydraulically actuated piston or piston head. As a result of this embodiment, various replacement device heads can be in a standby position, ie in an open position, for example for loading or pressing tools. Here, it also proves to be advantageous that after attaching such a trained replacement head device to the hand pressing the hydraulically actuated piston or the piston head is in its definable return position return position. In the simplest way can be done by the inventive design replacement of the device head. The pot-shaped or disk-shaped piston head, which is provided with a hydraulic seal, for example in the form of an O-ring seal with a support ring, remains in the device-side hydraulic cylinder. The piston stem, however, is a separate part and is assigned to the device head together with the return spring. In an advantageous manner, the manual press basic unit can be preassembled, for example, after repair work, filled with oil and tested. If necessary, an assignable device head is mounted. Furthermore, in the case of repair module head or basic devices can be exchanged in a simple manner in modules. In addition, depending on the application, for example. Be exchanged between press and Schneidgeräteköpfen, the exchange is due to the bipartite of the piston on the dry side of the device. The hydraulic side remains securely closed by the piston head remaining in the device, eliminating the need for cumbersome venting of the system.

For advantageous further development, it is provided that the piston skirt only pressurizes the piston head without being connected to it. It is provided a two-part piston, with a hand pressing the associated piston head and the device head associated piston skirt. The hydraulically acted upon actuation of the device piston head presses on the piston shaft connected to the latter tool carrier in the working position for Velpressing or cutting objects. By manual operation or by automatic triggering when a predetermined pressure is exceeded, the piston skirt moves with the tool carrier under pressure of the piston head back to the normal position. This return movement is preferably effected by acting on the piston shaft return spring. Piston shaft and piston head are not connected to each other, so that a decrease in the piston head provided with the device head has no influence on the piston head. The latter remains in each case in its position, preferably in the return position, for sealing the rearward against this pending oil.

With regard to an advantageous development of the subject matter, it is proposed that the piston skirt is detachably connected in operation to the piston head. According to the previous Ansungen also in this solution, the piston is formed in two parts, with a Handpreß the basic unit associated piston head and the device head associated piston skirt. For example. Here, a releasable connection between piston skirt and piston head may be provided, which is accessible from the outside for removal of the device head of the hand pressing device. Conceivable here is an axial screw or a bayonet connection between the piston skirt and piston head. To decrease the head of the device, this connection is solvable, after which the head of the device is in the simplest way removable from the hand press. Again, the sealing piston head remains in the base unit.

It is further proposed that a compression spring is bound to return the piston to the piston skirt. Accordingly, the piston shaft, even with the device head removed from the device, always in a basic position - preferably an open position of tools - acted upon. It is further provided that the piston head piston side has a centering recess or a centering projection and that the piston shaft piston head side has a centering projection or a Zentrierausnehmung. According to this embodiment, the two parts of the two-part piston transmit each other only pressure and lateral forces. In addition, given by the design centering properties for accurate axial alignment of the piston skirt. Alternatively or in combination, it can be provided that in the piston skirt piston head side a cylinder head screw mounted with protruding cylinder head centrally, is for centering on the piston head, wherein the cylinder head comes into a corresponding recess of the piston head for receiving. In a further embodiment of the subject invention is provided that the device head-side return spring comprises the piston skirt and one end of the device head and the other end in the region of the free, the piston head associated end of the piston skirt is supported on this. For this purpose, a radial expansion can be provided on the piston shaft, which at the same time forms a centering projection. The device-side piston head is disc-shaped in a preferred embodiment and has a radial seal. Alternatively, it can also be provided that the piston head has a piston shaft side pot wall whose outer diameter is adapted approximately to the inner diameter of the hydraulic cylinder. The pot wall takes in the coupled state of the device head and hand pressing the piston skirt, possibly with the surrounding return spring. In particular, with regard to the guiding properties of the piston head, it proves to be advantageous that the height of the pot wall in the axial direction corresponds to more than a quarter of the shaft length. In addition, the pot wall can also serve as an end stop during the pressing process, wherein the end ring surface of the pot wall occurs against a radially inwardly projecting into the path of the collar of the device head. With regard to the determination of the device head on the base unit, it is proposed that the hydraulic cylinder at its device head end has an external thread and the device head is connected by means of this thread with the hydraulic cylinder. As a result, the device head can be unscrewed from the handset in the simplest way with simultaneous withdrawal of the piston skirt together with the return spring from the hydraulic cylinder, wherein the remaining in the basic unit piston head retains its position. It proves to be particularly advantageous here that the connection position between Device head and hydraulic cylinder is set by an index pin. As a result, a defined connection position is given. When the predefined connection position is reached, the index pin enters a recess in the hydraulic cylinder in a spring-assisted manner. It is further proposed that the piston skirt is stepped and is connected by means of a device head supported, abutting against the step surface Gegenhalterteiles with the device head. This counterpart part on the one hand forms a stop surface for the tool carrier. At the opposite side of this stop surface is preferably supported on the piston shaft acting on the return spring. Advantageously, this counter-holder part is supported against a device head-side stage and is plugged in the simplest way. Alternatively, however, it can also be provided that the counter-holder part is screwed into the, the hydraulic cylinder receiving bore of the device head using the same thread for connecting the device head to the hydraulic cylinder. Particularly advantageous in terms of handling is an embodiment in which the device head has a handle. This is further preferably designed so that the handle extends in the direction of movement of the piston or the hydraulic cylinder. Finally, it is provided that the handle is formed by a transition on both sides in the device head arch part.

Fig. 1

ein erfindungsgemäßes hydraulisches Handpreßgerät mit einem zuordbaren, Auswechsel-Gerätekopf in perspektivischer Darstellung;

Fig. 2

eine partiell geschnittene Seitenansicht hierzu;

Fig. 3

eine der Fig. 2 entsprechende Seitenansichtsdarstellung, nach Verbinden des Auswechsel-Gerätekopfes mit dem Handpreßgerät, die unbeaufschlagte Grundstellung betreffend;

Fig. 4

eine der Fig. 3 entsprechende Darstellung, eine druckbeaufschlagte Arbeitsstellung betreffend;

Fig. 5

eine Detailvergrößerung des Bereiches V-V in Fig. 4;

Fig. 6

in Perspektive eine weitere Kombination aus einem handbetätigbaren Preßgerät mit einem weiteren Auswechsel-Gerätekopf;

Fig. 7

eine partiell geschnittene Seitenansichtsdarstellung zur Fig. 6;

Fig. 8

eine Schnittdarstellung eines weiteren Auswechsel-Gerätekopf, zuordbar einem Hydraulik-Zylinder mit einem Kolbenkopf in einer zweiten Ausführungsform.

The invention with reference to the accompanying drawings, which only illustrates several embodiments, explained in more detail. It shows:

Fig. 1

an inventive hydraulic Handpreßgerät with an assignable, replacement device head in perspective view;

Fig. 2

a partially sectioned side view of this;

Fig. 3

one of the Fig. 2 corresponding side view representation, after connecting the replacement head with the Handpreßgerät, the unbeaten basic position concerning;

Fig. 4

one of the Fig. 3 corresponding representation concerning a pressurized employment;

Fig. 5

a detail enlargement of the area VV in Fig. 4 ;

Fig. 6

in perspective, another combination of a hand-operated pressing device with another replacement head device;

Fig. 7

a partially sectioned side view of the Fig. 6 ;

Fig. 8

a sectional view of another replacement device head, assignable to a hydraulic cylinder with a piston head in a second embodiment.

Shown and described is first with reference to Fig. 1 an electric motor operated, hydraulic hand press 1. Such a pressing device is from the above-mentioned DE-A1 197 16 804 known.

In the Handpreßgerät 1, an electric motor is arranged. The drive of this electric motor via a, integrated in a handle 2 accumulator 3. When a finger-operable switch 4 is pumped from a reservoir oil into a pressure chamber, whereby a piston, according to the invention a piston head 5 is moved in the direction of its working end position.

This in Fig. 6 shown Handpreßgerät 1 is designed as a lever-operated implement. The pressure required for the displacement of the piston head 5 is therefore not electromotive, but manually operated via a pump lever 6.

Regardless of the design of Handpreßgerätes 1, this one, the plate-like, a radial seal 7 having piston head 5 enclosing hydraulic cylinder 8, to which a replaceable device head 9 can be arranged. In the Fig. 1 to 4 a first device head 9 is shown, the tool carrier 10, 11 can be equipped with pressing tools, not shown.

In the Fig. 6 and 7 is another replacement device head 9 shown. Another replacement device head 9 shows Fig. 8 , This is designed as a universal device head for receiving different tools. Regarding the design of this device head 9 in Fig. 8 will be on the non-pre-published German patent application 199 26 481 directed.

The formation of the device-side tool holder receptacle formed from hydraulic cylinder 8 and piston head 5, regardless of the design of the hand pressing device 1 is formed substantially the same. This also applies to the connection area of the different replacement device heads 9. As a result, each replacement head 9 is both the Handpreßgerät 1 according to Fig. 1 as well as the pump lever hand press 1 according to Fig. 6 assignable.

The substantially pot-shaped hydraulic cylinder 8 is the device head 9 facing open formed and serves for a innenwandig for guiding the piston head 5 and the other outside to connect the hand pressing device 1 with the device head 9, to which the hydraulic cylinder 8 externally an external thread 12th has.

As mentioned, the first disk-shaped piston head 5 is provided with a hydraulic seal 7, for example in the form of an O-ring seal with support ring, for sealing against the hydraulic cylinder inner wall.

In a pot-like configuration of the piston head 5 according to the embodiment in Fig. 2 is the piston head 5 is provided with a coaxially aligned pot wall 13, which is externally supported on the inner wall of the hydraulic cylinder 8.

The height of the pot wall 13 - measured in the direction of displacement of the piston head 5 - corresponds approximately to half of the measured depth of the hydraulic cylinder 8 measured in the same direction.

The device-side piston head 5 has on the device head 9 associated side on a circular, central stepped recess, a first diameter-larger centering recess 14 and a second subsequent diameter-reduced recess 15th

The in the Fig. 1 to 5 shown device head 9 has a displaceable by means of Handpreßgerätes 1 tool carrier 10 and an opposed fixed tool carrier eleventh

At the rear, the displaceable tool carrier 10 is provided with a piston shaft 16, which according to the illustrated embodiment is formed integrally with the tool carrier 10. Alternatively, the piston shaft 16 may also be screw-connected to the tool carrier 10, for example.

According to this embodiment, the piston acting on the tool carrier 10 is designed in two parts, with part-of the piston head 5 being arranged on the device side and the second part -the piston shaft 16 being arranged on the device head side.

The piston shaft 16 is stepped in the transition region to the tool carrier 10 such that in this area an opposite the piston shaft diameter enlarged, acting in the opening direction of the device head 9 Auschlagfläche 17 is formed.

This stop surface 17 occurs in the open position according to Fig. 2 against a, inserted into one of the piston shaft 16 passing through hole 18 inserted counter-holder 19. The latter is annular and is abutment-limited against a step 20 of the bore 18 is inserted. The piston shaft 16 passes centrally through the counter-holder 19 centering this.

The bore 18 is diameter-matched to the outer diameter of the hydraulic cylinder 8 and has a male thread 12 assignable internal thread 21st

The piston shaft diameter corresponds approximately to half the diameter of the bore 18th

The encompassed by a compression spring 22 piston shaft 16 passes through the bore 18 in the middle and occurs with its free end about a quarter of its total length from the bore 18. This free end of the piston shaft 16 is provided with a front side, opposite the piston shaft diameter enlarged support disc 23 which serves on the one hand the support of the compression spring 22 and on the other hand as a centering projection 24 for receiving in the centering recess 14 of the piston head 5. As a result, the centering projection diameter is adapted to the centering diameter of the piston head 5. Furthermore, the thickness measured in the axial direction of the centering projection 24 or the support disk 23 corresponds to the correspondingly measured depth of the centering recess 14.

The support disk 23 is fixed to the piston shaft 16 by means of an axially arranged cylinder head screw 25, wherein the cylinder head 26 projects beyond the support disk 23. The provided in the piston head 5 second recess 15 is adapted to the diameter and the measured height of the cylinder head 26 in the axial direction.

The mentioned compression spring 22 is supported, as described, at one end on the piston shaft side support plate 23 and the centering projection 24 formed thereby and at the other end on the, at the same time the stop for the piston shaft 16 and the movable tool carrier 10 forming counter-holder 19 from. As a result, the piston skirt 16 together with the tool carrier 10 is always in an open position Fig. 2 spring biased.

The device head 9 as shown in the Fig. 1 to 5 is also provided with a handle 27 which extends in the direction of movement of the piston shaft 16 and the displaceable tool carrier 10. Specifically, the handle 27 is arranged on the underside of the device head 9, wherein the handle 27 is formed by a on both sides in the device head 9 over arch part 28.

The device head 9 is the simplest way the Handpreßgerät 1 assignable. Thus, the device head 9 is pushed over the hydraulic cylinder 8 and screw-connected by means of the device-side external thread 12 and the meshing, device head-side internal thread 21. The predetermined connection position according to Fig. 3 between the device head 9 and the hydraulic cylinder 8 is defined by an index pin 29. The latter is arranged on the device head 9 and occurs in the predefined connection position spring-assisted in a radially outwardly formed on the hydraulic cylinder 8 radial groove 30 a.

In the work readiness position according to Fig. 3 is the centering projection 24 of the piston skirt 16 in the associated Zentrierausnehmung 14 of the piston head 5 and beyond the further centering properties possessing cylinder head 26 of the cylinder head screw 25 received in the second recess 15.

The pot wall 13 of the piston head 5 includes a portion of the compression spring 22nd

According to the two-part embodiment of the piston, the piston head 5 and the piston shaft 16 transmit mutually only compressive forces and beyond by the positive reception of the centering projection 24 in the centering 14 also lateral forces. Traction forces are not transmitted by the missing connection.

Upon actuation of the Handpreßgerätes 1 oil is pumped into a pressure chamber, whereby the piston head 5 is moved against the action of the return spring 22 in the direction of its working end position.

The return movement of the piston head 5 but takes place the return compression spring 22 which acts on the centering projection 24 the piston head 5, as soon as a return valve opens due to the exceeding of a predetermined maximum pressure.

The hydraulic cylinder 8 or the receptacle formed thereby for a replacement device head 9 as shown in the Fig. 6 and 7 is formed equal to the cylinder of the previously described hand-pressing device.

The device head 9 in the Fig. 6 and 7 on the other hand, with regard to the design of the piston skirt 16, constructive deviations occur, but while maintaining the compatibility with the device head 9 described above.

Here, the piston skirt 16 is formed as a hollow cylindrical component with an on, the piston head 5 assignable end integrally formed centering projection 24, which is also the support for the piston shaft 16 comprehensive return spring 22. The cooperating with the anvil 19 stop surface of the piston shaft 16 is formed here by a shell side arranged on the shaft ring 31.

In a device head 9 formed in this way, centering takes place only via the larger-diameter centering projection 24 and the assignable centering recess 14 of the piston head 5.

In addition, a centering directly in the cylinder bore of the hydraulic cylinder 8 is conceivable, especially in an embodiment of the piston head 5 in the form of a disc as shown in FIG Fig. 8 ,

It is also conceivable to screw the counter-holder 19 into the bore 18 of the device head 9 receiving the hydraulic cylinder 8.

According to Fig. 8 the free end region of the piston skirt 16 can also be formed with an integrally formed radial collar for forming the centering projection 24, on which a support disk 23 pushed over the piston skirt 16 is supported for the return spring 22, facing away from the piston head.

Further, according to the embodiment in FIG Fig. 8 the counter-holder for guiding the piston shaft 16 may also be formed as a radially inwardly projecting annular collar of the device head 9.

Advantageously, by the two-part embodiment of the piston according to the invention with simultaneous assignment of the return spring 22 to the device head 9, the various illustrated device heads 9 to the different hand press 1 according to Fig. 1 and Fig. 6 to be ordered. Thus, module head 9 or basic units 1 can be exchanged in a simple manner in modules. Depending on the application, the user can switch between, for example, pressing and cutting device heads or between electric or lever-actuated basic devices.

The replacement always takes place on the dry side, ie. H. the hydraulic side always remains closed by the piston head 5 remaining in the basic unit.

Furthermore Handpreßgeräte 1 can also be pre-assembled according to this design, filled with oil and tested, after which, if necessary, a suitable device head 9 is mounted.

Claims (15)

1. A hand-held hydraulic pressing apparatus (1) with a hydraulic cylinder (8) in which a hydraulically actuated piston can be displaced to carry out a pressing or cutting operation, with a piston head (5) on the apparatus and a tool carrier (10) which is part of an interchangeable apparatus head (9) and is connected to a piston shank (16), the interchangeable apparatus head (9) having a return spring (22) for return of the piston on the piston shank (16).
2. A hand-held pressing apparatus according to Claim 1, characterized in that the piston shank (16) merely subjects the piston head (5) to pressure without being connected to it.
3. A hand-held pressing apparatus according to Claim 1 or 2, characterized in that the piston shank (16) is connected to the piston head (5) in a manner which allows it to be operationally released.
4. A hand-held pressing apparatus according to any of Claims 1 to 3, characterized in that a compression spring (22) for return of the piston is held captive on the piston shank (16).
5. A hand-held pressing apparatus according to any of Claims 1 to 4, characterized in that the piston head (5) has a centring recess (14) or a centring projection on the piston-shank side and in that the piston shank (16) has a centring projection (24) or a centring recess on the piston-head side.
6. A hand-held pressing apparatus according to Claim 5, characterized in that a cylindrically-headed screw (25) with a projecting cylindrical head (26) is mounted centrally in the piston shank (16) on the piston-head side to effect centring on the piston head (5), the cylindrical head (26) being received in a corresponding recess (15) in the piston head (5).
7. A hand-held pressing apparatus according to any of Claims 1 to 6, characterized in that the piston head (5) has a cup wall (13) on the piston-shank side.
8. A hand-held pressing apparatus according to Claim 7, characterized in that the height of the cup wall (13) corresponds to more than a quarter of the length of the shank.
9. A hand-held pressing apparatus according to any of Claims 1 to 8, characterized in that the hydraulic cylinder (8) has an external thread (12) at its end facing the apparatus head and the apparatus head (9) is connected to the hydraulic cylinder (8) by means of this thread (12).
10. A hand-held pressing apparatus according to any of Claims 1 to 9, characterized in that the location of the connection between the apparatus head (9) and the hydraulic cylinder (8) is defined by an index pin (29).
11. A hand-held pressing apparatus according to any of Claims 1 to 10, characterized in that the piston shank (16) is of stepped form and is connected to the apparatus head (9) by means of a counterholder component (19) which is supported on the apparatus head (9) and engages against the step face.
12. A hand-held pressing apparatus according to Claim 11, characterized in that the counterholder component (19) is screwed into the bore in the apparatus head (9) which accommodates the hydraulic cylinder (8).
13. A hand-held pressing apparatus according to any of Claims 1 to 12, characterized in that the apparatus head (9) has a handle (27).
14. A hand-held pressing apparatus according to Claim 13, characterized in that the handle (27) extends in the direction of movement of the piston or hydraulic cylinder (8).
15. A hand-held pressing apparatus according to either of Claims 13 and 14, characterized in that the handle (27) is formed by an arc-shaped component (28) which merges into the apparatus head (9) at both ends.

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