GB2103524A - Tool changing apparatus for hammer forging press - Google Patents

Abstract

Tool changing apparatus for at least two lower tools of a hammer forging press comprises a slidable press bed 1 with guide bars 5 extending at right angles to the sliding direction for the lateral guidance of the lower tools 4, 8, 9 to slide transversely on or outside the press bed 1. In the working position, each lower tool 4, 8, 9 has bars 4a, 8a, 9a, extending parallel to the sliding direction of the press bed 1. Engaging over the bars 4a, 8a, 9a are the corresponding clamping bars 10a, 11a, 12a, 13a of lateral pressure members 10, 11, 12, 13, which are also guided in the changing direction extending at right angles to the sliding direction of the press bed 1 and are able to slide at the same time as the tools. Stationary clamping apparatus is operable to clamp the pressure members in position with their clamping bars. <IMAGE>

Description

SPECIFICATION Changing apparatus for at least two lower tools of a hammer forging press The invention relates to a changing apparatus for at least two lower tools of a hammer forging press, consisting of a press bed able to slide along the main axis of the press with guide bars extending at right angles to the direction of movement for the lateral guidance of lower tools able to slide by a transverse movement on the press bed or afterwards outside the press bed. By means of a changing apparatus of this type it is possible to bring various lower tools or lower saddles by transverse displacement quickly to the press bed, in which case the possibility of sliding the press bed along the main axis of the press serves for shifting the lower tool with respect to the upper tool to a greater or lesser extent in a relative manner, which is necessary for carrying out removal or alignment work.

In the previously known constructions of changing apparatus of the aforedescribed type, the lower tool located on the press bed is seated loosely or is solely fixed to the press bed between guide bars extending at right angles to the direction of movement, because with the considerable formation of hammer scale during the forging operation, a mechanical or hydraulic locking of the tools on the press bed cannot be carried out in an operationally reliable manner, on account of the necessary movable power supply. However, the loose arrangement of the lower tool on the press bed has considerable drawbacks, because during the forging operation, due to the handling of the forgings, tilting forces are also exerted on the tool, due to which the tool can be raised, so that hammer scale arrives between the lower tool and the press bed and results in wear phenomena on both parts.

It is an object of the invention to develope a changing apparatus of the aforementioned type to the effect that the lower tool located on the press bed is to be clamped to the press bed by stationary clamping devices and in particular for each possible sliding position of the press bed together with the lower tool on both sides of the central position, which the tool assumes after transverse displacement in the changing direction.

The solution of this object consists according to the invention in that in the working position, each lower tool has bars extending parallel to the sliding direction of the press bed, engaging over which bars are corresponding clamping bars as lateral pressure members, which like the tools are guided in the changing direction extending at right angles to the sliding direction of the press bed and can be displaced at the same time as the tools and that the pressure members situated on both sides of the tool respectively located on the press bed in the working position are in the range of action of stationary clamping apparatus moving the pressure members downwards with their clamping bars within the limits of a vertical clearance of motion.

With the stationary clamping apparatus, first of all the problem of the movable energy supply for hydraulically operated clamping apparatus for example is obviated. In addition, since the transmission of clamping forces takes place by way of the cooperation of movable clamping bars and counter-bars adjacent the tool, which extend over a certain length in the direction of the sliding movement of the press bed, for each sliding position of the press bed, the lower tool can be clamped to the latter, provided that the clamping bars and counter-bars do not cease to be congruent. Over the length of the clamping bars and the corresponding counter-bars adjacent the tool, one thus has the possibility of clamping the lower tool to the press bed in a desired range of movement on both sides of the central position, in order to carry out removal or alignment work.

In a development of the invention it is proposed that assiciated with adjacent lower tools is a common pressure member of Tshaped cross section with two diametrical clamping bars, by means of which the pressure members are supported by the corresponding bars of the tools, in which case for moving the tools together with the pressure members in the changing direction, a sliding apparatus is provided acting in a pushing manner on the outer pressure members or acting in a pulling and pushing manner in the case of a tension-proof connecton between the pressure members and tools.In this case, the pressure members supported by the bars adjacent the tools, between adjacent lower tools serve for transmitting the sliding forces acting alternately in the direction of the transverse displacement or in the changing direction on the outer pressure members, so that the pressure members need to be guided solely laterally.

Since the pressure members accompanying the transverse displacement of the tools in the changing direction should arrive in the range of stationary clamping apparatus, according to the invention stationary locking blocks for guiding the pressure members and for receiving the clamping apparatus are located on both sides of the press bed.

Constructional possibilites for hydraulic clamping apparatus are described in patent claims 4 and 5 and described in detail in the description referring to the drawings. It is within the scope of the invention that the locking blocks are constructed as lateral guides for the sliding press bed and'arse provided with clamping apparatus for fixing of the press bed in different sliding positions, which is useful for the absolute fixing of the lower tool located on the press bed in the last analysis with respect to the press frame in each sliding position of the press bed.

The drawings show one embodiment of a changing apparatus for three lower tools to be changed by transverse displacement and in particular.

Figure 1 is a partial plan view.

Figure 2 is a view in the direction of arrow Xof Fig. 1, Figure 3 is a section on line A-B of Fig. 1, the tools not being shown in section and Figure 4 is a partial section on line C-D of Fig. 1, to an enlarged scale.

Figs. 1 and 2 show the press bed 1, which is able to slide on the press frame (not shown) horizontally in the direction of arrows 2 and 3, which in the reverse direction of action also represent the sliding cylinders. The lower tool 4 required for carrying out the forging work is located on the press bed. The tool 4 is guided between guide bars 5 extending at right angles to the sliding direction, which bars 5 are attached to the press bed. Further lower tools 8 and 9 are located in the changing direction, i.e. at right angles to the sliding direction of the press bed 1, on both sides of the lower tool 4 and are likewise guided on the enlarged press frame (not shown).The arrows 6 and 7 in Fig. 1 indicate the transverse displacement directions to be adjusted optionally and at the same time with a respective reversed direction of action represent the two sliding drives, which act in a pressing manner respectively on the outer tools 8 and 9, in order to introduce the respective required tool to the press bed 1 between the guide bars 5. Outside the press bed, the tools are guided by lateral guide bars 5a.

Figs. 2 and 3 shows that the lower tools 4, 8 and 9 have opposed bars 8a, 4a and 9a on their base, whereof one bar 4a is shown in Fig. 2. Engaging over these bars on the base of the tools are correspondingly clamping bars 1 0a, 11 a, 1 2a and 1 3a of pressure members 10, 11, 12 and 13 able to slide with the tools. The pressure members 11 and 1 2 located between adjacent lower tools are Tshaped and accordingly have two clamping bars 11 a, 1 2a, or which, however, when clamping the lower tool 4 for example to the press bed 1, only the clamping bars 11 a and 1 2a associated with the counter-bars 4a of the tool 4 are required.A tension-proof connection between the pressure members and the lower tools adjacent thereto does not exist in this embodiment, since serving for the transverse displacement of a set of lower tools together with the pressure members are two sliding drives, which act in a pressing manner on the outer pressure members 10 or 1 3. The T-shaped pressure members 11 and 1 2 are supported by the adjacent bars of the lower tools and transmit the pressure-sliding forces when changing the tool. A double-acting sliding drive is sufficient if the bars of the pressure members and tools are interconnected in a tension-proof manner by positive interengagement by means of a bar and groove.

Located on both side of the press bed 1 are stationary U-shaped locking blocks 14, 1 5 for guiding the pressure members and for receiving clamping apparatus of which one clamping apparatus is shown to an enlarged scale in Fig. 4. This shows the right-hand part of the locking block 1 5 into whose guide mounting the pressure member 1 2 has been introduced, when the lower tool 4 rests on the press bed 1 in the working position. Each clamping apparatus consists of a locking bolt 1 7 which can be moved to and fro horizontally and whose head 1 7a is chamfered in the form of a wedge, in whose range of action three of the four pressure members can arrive by transverse displacement, depending on which tool has been pushed above the press bed 1.

The pressure members--in in Fig. 4 the pres- sure member 12 have lateral recesses for example 1 2b with clamping faces extending obliquely and corresponding to the head 17a, so that the pressure members can be pushed downwards on the basis of a vertical clearance of motion, when the locking bolts 1 7 located on both sides of the pressure members are introduced into the recesses 12b, in which case due to a wedge effect between the heads 1 7a and the inclined counter-faces in the recesses 12b, downwardly directed clamping forces are produced.These clamping forced are imparted to the clamping bars for example 1 2a of the pressure member 12, so that by actuating the clamping apparatus associated with the pressure member 12, the tool 4 is clamped firmly on the press bed 1 by its righthand bar 4a adjacent the base.

As shown in Fig. 4 each locking bolt 1 7 is guided in a laterally raised side of a U-shaped locking block 14, 1 5 and is connected by way of cross bars 1 8 to a piston rod 1 9 of a double-acting pitch-operating cylinder 1 6 fitted in the locking block below the associated locking bolt 1 7. With regard to the wedge shape of the head 17a, the locking bolts 1 7 are guided in a non-rotory manner by way of the cross-bars 1 8. The spatial separation of the locking bolts 1 7 from the actual clamping cylinders 16, 1 9 is however advantageous for reasons of space.

As Fig. 3 shows, the locking blocks 14 and 1 5 are a.so constructed as lateral guides for the sliding press bed 1 and are provided with clamping apparatus for fixing the press bed in different sliding positions. These clamping apparatus consist of locking bolts 20 with wedge-shaped heads similar to those of the locking bolts 17, which are actuated directly by clamping cylinders 21.

The method of operation of the aforedescribed changing apparatus according to the invention is as follows: With reference to Fig.

3 it is assumed that the lower tool 4 was introduced from the right or left between the guide bars 5 of the press bed 1 set in the central position, by transverse displacement in the changing direction. In this case, the accompanying pressure members 11 and 1 2 arrive above the locking blocks 14 and 1 5 and thus in the range of action of the clamping apparatus according to Fig. 4. If these clamping apparatus are actuated, i.e. the locking bolts are moved inwards, the pressure members 11 and 1 2 experience a downwards movement and thus clamp the tool on the press bed 1 by way of the clamping bars 11 a and 1 2a associated with the diametral bars 4a on the base of the tool 4.As a result of the elongated extent of the cooperating bars 4a, 11 a and 12a, this clamping operation is also effective when the lower tool 4 has been shifted along the main axis of the press defined by the directions of movement 2 and 3 due to sliding of the press bed 1. When releasing the clamping force, a displacement of the press bed with the tool along this main axis is possible and the tool may once more be clamped to the press bed, as long as the bars 4a on the bottom of the tool have not been moved out of the clamping region of the clamping bars 11 a and 1 2a of the pressure members 11 and 1 2. A greater sliding movement for the press bed 1 is generally only required in the case of conveying or alignment work, in which case it has to be accepted that the bars 4a leave the range of action of the clamping bars 11 a and 12a.

It will be understood that before and after each of the displacements of the press bed 1, the clamping apparatus 20, 21 for the press bed are released and re-positioned, in order that at the time of forging, the tool 4 can be clamped in the respective position within the main axis not only relative to the press bed 1, but also relative to the press frame (not shown), in that the press bed 1 itself can be clamped with respect to the press frame.

If the tool 8 for example is to be moved above the press bed 1, the press bed 1 is brought into the central position, so that the guide bars 5 are centered with the guide bars 5a. After this, the left-hand sliding apparatus 6 is actuated, which acts on the pressure member 10 and all the tools together with the pressure members are moved transversely towards the right, until the pressure member 10 is located above the locking block 14 and the pressure member 11 is located above the locking block 1 5. Thus, the pressure members 10 and 11 come into the range of action of the clamping apparatus according to Fig. 4, which are stationary and nevertheless make it possible to clamp tools in various positions along the main axis of the forging press.

Claims (7)

1. Changing apparatus for at least two lower tools of a hammer forging press, comprising a press bed able to slide along the main axis of the press with guide bars extending at right angles to the sliding direction for the lateral guidance of the lower tools able to slide by transverse movement on the press bed or afterwards outside the press bed, wherein in the working position, each lower tool has bars extending parrallel to the sliding direction of the press bed, engaging over which bars are the corresponding clamping bars of lateral pressure members, which like the tools are guided in the changing direction extending at right angles to the sliding direction of the press bed and are able to slide at the same time as the tools, and the pressure members situated on both sides of the tool respectively located on the press bed in the working position are in the range of action of stationary clamping apparatus moving the pressure members with their clamping bars downwards within the limits of a vertical clearance of motion.

2. Changing apparatus according to claim 1, wherein associated with adjacent lower tools is a common pressure member of Tshaped cross-section comprising two diametral clamping bars, by which the pressure members are supported by the corresponding bars of the tools, and provided for moving the tools together with the pressure members in the changing direction is a displacement apparatus acting in a pressing manner on the outer pressure members or in the case of a tensionproof connection between the pressure members and tools, a displacement apparatus acting in a pulling and pushing manner.

3. Changing apparatus according to claim 1 or 2, wherein stationary locking blocks for guiding the pressure members and for receiving the clamping apparatus are arranged on both sides of the press bed.

4. Changing apparatus according to claim 3, wherein the clamping apparatus comprises locking bolts able to move to and fro horizontally with heads chamfered in a wedge shape, which can be inserted in corresponding lateral recesses in the laterally movable pressure members and produce downwardly directed clamping forces.

5. Changing apparatus according to claim 4, wherein the locking bolts are guided in laterally raised sides of the U-shaped locking blocks and are connected by way of crossmembers respectively to a piston rod of a double-acting pitch-operating cylinder fitted in the locking block below the associated locking bolt.

6. Changing apparatus according to claim 3, wherein the locking blocks are constructed as lateral guides for the sliding press bed and are provided with clamping apparatus for fixing the press bed in various sliding positions.

7. Changing apparatus substantially as hereinbefore described with reference to the accompanying drawings.