DD294209A5 - METHOD AND DEVICE FOR BROKEN-SEPARATING CONNECTORS - Google Patents

Abstract

The invention relates to a method and apparatus for fracture separation of cap and rod of connecting rods produced in powder forging technology. It is a method for fracture separation of cap and rod of connecting rods made in powder forging technology, in which the cap or the rod of the connecting rod is clamped on a movable transversely to the fracture separation plane holder, which is not held fixed to the holder part of the connecting rod, and acting on the holder in the fracture separation direction acting in the axis of symmetry of the connecting rod straight central Stosz. An apparatus for carrying out the method comprises: a stationary fixture base * a holder (7) for the cap (28) of the connecting rod * a holder for the rod of the connecting rod, a mounted on the device base guide for each holder on which the respective holder respectively transverse to the fracture separation plane and parallel to the axis of symmetry of the connecting rod is mounted movable within limits, and a striking mass (3) for each holder, the impact masses simultaneously exert on the respective holder in the fracture separation direction of the connecting rod acting in its axis of symmetry straight central Stosz. Fig. 1 {fracture separation; Powder Forging Technology; connecting rods; Cap; Pole; Holder; straight, central thrust; fixed device base; Halterungsfuehrung; Striking mass; Fracture separation plane}

Description

For this 3 pages drawings

Field of application of the invention

The present invention relates to a method and apparatus for fracture separation of the cap and rod of connecting rods made by powder forging technology.

Characteristic of the known state of the art

Known methods for fracture separation of the cap and rod in connecting rods are based in principle on the measure to let act on the inner surface of the big eye of the connecting rod by means of special devices, a "Aufweitkraft" and increase it until the breaking point of the connecting rod material is reached and cap and rod are separated by breakage (Principle: see Fig.6 of US-PS 4569109).

In order to be able to realize the fracture at a precisely predetermined location, notches are provided on the inner surface of the large eye and partly also on its outer surface, the notch effect of which determines the fracture profile (compare US Pat. Nos. 4,669,109 and 4,693,139).

There are also known fracture separation methods in which bores are provided in the connecting rod in the desired fracture plane, via which by "Aufweitdorne" (see Fig.3 of US-PS 3994054) required for fracture separation forces are introduced into the connecting rod material.

Since such mechanical fracture separation methods u.a. Because of the unfavorable friction conditions, in particular for series production are not suitable, procedures have already been developed in which the expansion force is generated hydraulically (see, US-PS 47 54906). However, such procedures are technically very complicated and do not provide optimal fracture separation results.

Object of the invention

The aim of the invention is to reduce the technical complexity and to increase the qualitative result in the fracture separation of connecting rods under the conditions of mass production.

Explanation of the essence of the invention

The invention has for its object to provide a completely novel method and apparatus for fracture separation of connecting rods, which has a simple structure and provides improved fracture results. This object is achieved according to the invention by a method which is characterized

- That the cap or the rod of the connecting rod is clamped on a movable transversely to the fracture separation plane bracket,

- That the not fixed to the bracket part of the connecting rod is held stationary, and

- That on the holder in the fracture separation direction acting in the axis of symmetry of the connecting rod straight central shock is exercised.

The gestte task is further solved by a further procedure, which is characterized

- That the cap and the rod of the connecting rod are respectively clamped on a movable transversely to the fracture separation plane bracket,

- That on the brackets each acting in the axis of symmetry of the connecting rod in Auseinanderbewegungsrichtung acting straight central shock is exercised.

The invention is based on the idea that optimal fracture results are always achieved when the fracture separation force can act abruptly on the one hand and on the other hand in this process, the connecting rod is rigid and clamped without play.

Especially the sudden initiation of the fracture separation force is not possible in known methods and devices, as in these always a certain amount of time is required for the construction of the fracture separation force.

Particularly good Druchergebnisse be achieved when the holder or the brackets are biased in the direction of impact to a value below the yield strength of the connecting rod and only in the prestressed state, a straight central shock is applied.

Experiments have shown that particularly good results are achieved when the preload force is equal to or less than 80% of the breaking load.

In principle, the brackets can be stored in various ways. Particularly good results are achieved when the brackets are mounted in a straight line parallel to the axis of symmetry of the connecting rod.

Tests have shown that the cap and rod of the connecting rod in the region of the fracture surface particularly tight, seamless and fit exactly, if immediately after the fracture separation operation, the cap and the rod are pressed together in the fracture separation plane with high compressive force.

Particularly good fitting results are achieved when the pressing force corresponds to the clamping force with which the cap and the bar are pressed together during later use of the connecting rod by the connecting rod screws.

In order to achieve optimum fracture separation results, the straight central joint must be precisely adapted to the respective connecting rod material used, the shape and the size of the fracture cross-sectional area and the respective arrangement of the measures influencing the fracture profile (such as the notches or the like). This is done by way of simple experiments, over which the central straight impact affecting masses and speeds are changed according to the particular circumstances.

A preferred apparatus for carrying out the method according to claim 1 comprises the following elements:

a fixed device base,

a receptacle for the fixed part of the connecting rod which is rigidly fixed on the device base,

- A holder for the non-stationary held part of the connecting rod, which is mounted in a mounted on the device base guide transversely to the fracture separation plane and parallel to the axis of symmetry of the connecting rod movable within limits, and

- An impact mass that exerts on the holder in the fracture separation direction of the connecting rod acting in its axis of symmetry straight central shock.

A variant of the device comprises the following elements:

a fixed device base,

a holder for the cap of the connecting rod,

- a holder for the rod of the connecting rod,

- A mounted on the device base guide for each holder on which the respective holder is mounted transversely movable in each case transversely to the fracture separation plane and parallel to the axis of symmetry of the connecting rod, as well as

- An impact mass for each holder, the impact masses simultaneously exert on the respective holder in the fracture separation direction of the connecting rod acting in its axis of symmetry straight central shock.

A particularly simple technical structure is achieved in the apparatus for performing the method according to claim 1, characterized in that the stationary device base is arranged upright and the impact mass is designed as a gravity-driven impact weight. In this way, no special drive for the impact weight is required. It only needs to be provided a simple lifting device with which the impact weight is returned to its raised starting position.

However, the stationary fixture base can also be placed horizontally. In such a case, a power drive for the striking mass or the weights is required. A particularly simple construction results when the power drive is designed as a hydraulic or pneumatically actuated acceleration cylinder for the impact weights.

In a standing arrangement can be provided in case of need to accelerate the gravitational impact weight additionally a hydraulic or pneumatic acceleration cylinder and supported in this way the gravity drive.

In principle, the stationary device base can be configured in leather in any desired manner. A particularly simple construction results when the device base is designed as a base plate. In a vertical arrangement, it is advantageous to integrate the base plate in a stator assembly.

The impact mass or the impact masses can be stored or guided in various ways. It is advantageous if the impact mass or the impact masses are mounted in a straight line and can be moved back and forth on a guide fastened to the device base.

As already mentioned, it is necessary for an optimal fracture separation result that the connecting rods are held rigidly and without play during the fracture separation process. This is achieved according to a preferred embodiment of the device according to the invention characterized in that the holder and the receptacle each have a projecting through the large connecting rod bore of the connecting rod, closely adjacent to the bore wall receiving pin having a circular cross-section. The dividing line between the two bolts lies exactly in the fracture separation plane.

It is advantageous if the holder is designed as a carriage, on which the receiving bolt is attached. The attachment should be designed in such a way that the locating bolt can not bend during the fracture separation process. This is achieved, in particular, when each receiving bolt is supported in the region of its free end in the direction of loading via a removable clamping bracket on the carriage or the holder.

For a possible backlash-free and rigid attachment of the connecting rod for the fracture separation process, it is expedient that the cap and / or the rod of the connecting rod in each case via fixing and abutment elements in the receptacle and the holder are clamped and in contact with the outer surfaces of the locating pin be pressed. The fixing and contact elements can be designed as normal clamping screws, which act from three sides on the cap or the rod of the connecting rod. However, the fixing and contact elements can also be actuated mechanically or hydraulically.

In principle, the impact masses can be configured in any desired manner. A particularly advantageous arrangement, however, results when the impact masses each formed yoke-like and two impact surfaces are equipped, which cooperate with counter-impact surfaces on the carriage, which are arranged on both Rare the recording pin and thus on both sides of the connecting rod on the carriage. In this way, the impact force of the respective impact mass is introduced into the carriage in such a way that it results in a fracture separation force lying exactly in the connecting rod axis.

As already mentioned, particularly advantageous fracture separation results are achieved when the holder or the holders are pretensioned in the direction of impact. According to a preferred embodiment, the device is equipped for this purpose with a biasing cylinder attached to the device base, which engages with its piston rod on the holder or the carriage.

In order to decelerate the mass of the holder or of the carriage after the fracture separation process has taken place, it is advantageous if in each case one or more damping cylinders are arranged in the movement path of the holder.

As already mentioned in connection with the procedure according to the invention, the straight central impact acting on the holder must be adapted to the respectively used connecting rod material, the shape and the size of the fracture cross-sectional area and the respective arrangement of the measures influencing the fracture profile (such as the notches o. Like.) Are adapted exactly.

This is done by way of simple experiments on a change in the weight of the impact mass (possibly also on a change in the weight of the brackets), as well as by changing the speed of the Schtagmasse. at

When the fixed device base is in a stationary arrangement, the speed of the impact mass can be varied by changing the fall height, if necessary in support of the acceleration cylinder. In a horizontal arrangement, this is done by a corresponding adjustment of the acceleration cylinder.

embodiment

In the following, an exemplary embodiment of an apparatus for carrying out the method is described in more detail with reference to the accompanying drawings for further explanation and for better understanding.

1 shows schematically an overall view of the device according to the invention, FIG. 2 shows a section in the plane H-II of FIG. 1, FIG. 3 shows schematically on an enlarged scale a detail of FIG.

4 shows a side view of the detail according to FIG. 3 in a partially exploded view, and FIG. 5 shows schematically in a perspective view, likewise in an exploded view, cutouts from the arrangement according to FIGS. 3 and 4.

As is apparent from Figs. 1 and 2, the device consists of a device base 1, which is formed in the present embodiment as a base plate. On the base plate 1 guide rails 2 are arranged, via which a striking mass 3 in the form of a yoke-like Schlaggewichtes in an axis 4 is reciprocally mounted. Following the guide rails 2 is on the device base 1 a about the yoke shape of the impact mass 3 adapted receptacle 5 rigidly attached. On the impact mass opposite side of the receptacle 5 1 guide rails 6 are fixed on the device base, via which a holder 7 in the direction of the axis 4 is mounted back and forth herverfahrbar. In the path of movement of the holder 7, two damping cylinder G are provided on the opposite side of the receptacle 5, the fastening on a plate 9 '. which is connected to the device base 1. The plate 9 carries on the damping cylinders 8 opposite side a biasing cylinder 10, the piston 11 protrudes through the plate 9 and is connected via a lock 12 with the bracket 7.

On the opposite side of the receptacle 5 the striking mass 3 is equipped with a Llement 13. This element 13 is a horizontal position of the device base 1, an acceleration cylinder 14, with which the impact mass 3 is accelerated towards the break separation in the direction of the holder 7.

With the arrangement of the device base 1, d. H. in a device in which the hammering mass 3 is formed as gravity-driven impact weight, the element 13 consists of a lifting cylinder, with which the striking mass 3 can be lifted after carrying out the fracture separation process back into its raised position and held there. In this version, the lifting cylinder is provided with a not shown latch arrangement with which the impact mass 3 can be unlatched to carry out the impact separation process in the raised position.

The impact mass 3 is yoke-shaped in the present case and has on its side facing the holder 7 on both sides of the receptacle 5 firing pin 15 whose impact surfaces 16 cooperate with counter-impact surfaces 17 on the top of the holder 7, as in Fig. 1 with dash-dotted lines is indicated.

The structure of the receptacle 5 and the holder 7 is shown schematically in Figs. 3 to 5. The receptacle 5 consists of a rigid mold part 18 which is fixedly connected to the device base 1 formed as a base plate. This molding 18 has the rod 19 of the connecting rod 20 adapted recesses. In the molded part 18, a receiving bolt 21 is further rigidly inserted, the pin 22 has the diameter of the large eye 23 of the connecting rod 20. As is apparent from Figures 3 and 5, both the receiving pin 21 and the pin 22 have a semi-circular cross-section.

The molding 18 also has four threaded holes in which screws are arranged. These screws provide fixing and abutment elements 24 for the rod 19 of the connecting rod 20, welcho the rod 19 for a fixed in the form of part 18 and thus in the receptacle 5 and press the other free play on the pin 22 of the receiving pin 21 of the receptacle 5.

The holder 7 is-as already mentioned in connection with Fig. 1-designed as a carriage, which is mounted on the guide rails 6 in the ash 4 (see Fig. 2) back and forth. The carriage is also equipped with a receiving bolt 25, which has a pin 26. The locating pin 25 and the pin 26 also have a semi-circular cross-section and complement the locating pin 21 and the pin 22 of the receptacle 5 to an arrangement that practically completely fills the large eye 23 of the connecting rod 22. The separation plane between the locating pin 21 and the locating pin 25 lies exactly in the fracture separation plane of the device.

On both sides of the locating pin 25, the holder 7 designed in the manner of a carriage is provided in the region of its upper side with the counter-striking surfaces 17 already mentioned in connection with the description of FIG. 1 for the striking surfaces 16 of the striking pins 15 of the striking mass 3.

The carriage also has four threaded holes in which screws are arranged, which serve as fixing and abutment elements 27 for the cap 28 of the connecting rod 20. By this fixing and contact elements 27, the cap 28 of the connecting rod is firmly clamped in the carriage and pressed against the pin 26 of the locating pin 25.

In order to prevent bending of the receiving bolts 21 and 25 in the fracture separation process, a groove 29 and 30 is provided in the region of the free end of both the pin 22 and the pin 26, in which the ends 31 and 32 of a bracket 33 and 34 respectively engage, each resting with its other end 35 and 36 in a groove 37 and on projections 38 (see Fig. 4 and

As is apparent from Fig. 5, both the groove 37 and the projections 38 have an inclination relative to the fracture separation plane, whereby the brackets 33 and 34 placed by sliding in the transverse direction clearance, biased and subsequently with the mold part 5 and the holder 7 vorschraubi can be. In this way, a bending of the pins 22 and 26 is excluded in the fracture separation process, since the free ends of the pins 22 and 26 via the brackets 33 and 34 on the molded part 18 and the bracket 7 are supported directly.

As is apparent from Fig. 5, the receiving bolts 21 and 25 are each separately producible parts, which are rigidly anchored in a corresponding recess in the molded part 18 and in the holder 7.

The fracture separation process is as follows:

First, the impact mass 3 is brought by the element 13 in its retracted position, as shown in Fig. 1.

Following this, the holder 7 is moved in the direction of the receptacle 5 and the connecting rod 20 is pushed onto the pins 22 and 26 respectively. Subsequently, the brackets 33 and 34 are applied and biased by lateral displacement and bolted to the molding or the holder 7. Subsequently, the fixing and contact elements 24 and 27 festgezoger. so that the connecting rod 20 is rigidly clamped both in the receptacle 5 and in the holder 7.

When standingi arrangement of the device base, the catch arrangement described above is then released so that the impact mass 3 fall under the influence of gravity down and kknn with the impact surfaces 16 of the firing pin 15 on the counter-striking surfaces 17 of the holder 7 ktnn. As a result, an impact force is introduced exactly centric in the axis 4, which lies in the connecting rod longitudinal axis, is carried out by i'ie the fracture separation process. In this phase, the holder 7 is accelerated and this movement is stopped by the damping cylinder 8.

If the holder 7 to be biased before the fracture separation process, the biasing cylinder 10 is applied and pulled over the piston rod 11 and the lock 12, the holder 7 in a direction away from the receptacle 5 direction.

In lying arrangement of the device base the impact mass 3 is accelerated by the acceleration cylinder 14.

Otherwise, the fracture separation process takes place in the already described Weiro.

After completion of the fracture separation process, the impact mass 3 is pushed back to the initial position and the preload cylinder 10 is relieved. Thereafter, the brackets 33 and 34 are unscrewed and the rod 19 and the cap 28 taken out of the device. The device is then free for another fracture separation process.

To improve the accuracy of fit then-as already described above-cap and rod with high pressure in a further operation again pressed together.

Claims (24)

1. A method for fracture separation of the cap and rod of connecting rods produced in powder forging technology, characterized - That the cap or the rod of the connecting rod is clamped on a movable transversely to the fracture separation plane bracket, - That the not fixed to the bracket part of the connecting rod is held stationary, and - That on the holder in the fracture separation direction acting in the axis of symmetry of the connecting rod straight central shock is exercised. Or - That the cap and the rod of the connecting rod are respectively clamped on a movable transversely to the fracture separation plane holder, and - That on the brackets each acting in the axis of symmetry of the connecting rod in Auseinanderbewegungsrichtung acting straight central shock is exercised. 2. The method according to claim 1, characterized in that the holder or the brackets biased in the shock direction to a value below the yield strength of the connecting rod material and subsequently the gerf.de central shock is exerted. 3. The method according to claim 2, characterized in that the biasing force is equal to or less than 80% of the refractive power. 4. The method according to claim 1, characterized in that the holder or the brackets are movable in a straight line and parallel to the axis of symmetry of the connecting rod. 5. The method according to claim 1, characterized in that immediately after the fracture separation process, the cap and the rod are pressed together in the fracture separation plane with high pressing force. 6. The method according to claim 5, characterized in that the pressing force corresponds to the clamping force with which the cap and the rod are laterally clamped during later use of the connecting rod by the connecting rod screws. 7. The method according to claim 1 to 6, characterized in that the central straight impact affecting masses and speeds are variable. 8. A device for fracture separation of cap and rod of powder forging technology produced connecting rods, characterized by: a fixed device base (1), - A receptacle (5) for the stationary held part of the connecting rod (20) which is rigidly mounted on the device base, - A holder (7) for the not held stationary part of the connecting rod (20), which is mounted in a fixed on the device base (1) guide transversely to the fracture separation plane and parallel to the axis of symmetry of the connecting rod within limits, and by - An impact mass (3) which exerts on the holder (7) in the fracture separation direction of the connecting rod acting in its axis of symmetry straight central shock. Or a fixed device base (1), a holder (7) for the cap (28) of the connecting rod (20), - a holder for the rod of the connecting rod, - A mounted on the device base guide for each holder on which the respective holder is mounted transversely to the fracture separation plane and parallel ;: For symmetry axis of the connecting rod within limits, and by - A striking mass (3) for each holder, the impact masses simultaneously exert on the respective holder in the fracture separation direction of the connecting rod acting in its axis of symmetry straight central shock. 9. Apparatus according to claim 8, characterized in that the stationary device base (1) is arranged vertically and the striking mass (3) is designed as a gravity-driven impact weight. 10. The device according to claim 8, characterized in that the stationary device base is disposed horizontally and the impact mass or the impact masses are designed as power-driven impact weights. 11. Apparatus according to claim 9 or 10, characterized in that the device base (1) is designed as a base plate. 12. Apparatus according to claim 9 and 11, characterized in that the base plate is integrated in a stator assembly. 13. The apparatus according to claim 10, characterized in that the power drive for the or the impact weights has a hydraulically or pneumatically actuated acceleration cylinder. 14. The apparatus according to claim 9, characterized in that the acceleration of the gravity-driven impact weight is supported by a hydraulic or pneumatic acceleration cylinder. 15. The device according to claim 8, characterized in that the impact mass (3) or the impact masses are mounted on a mounted on the device base (1) guide straight back and forth herverschiebbar. 16. The apparatus according to claim 8, characterized in that the holder (7) and the receptacle (5) each have a projecting through the large connecting rod bore, closely adjacent to the bore edges receiving bolts (21 and 25) have semicircular cross-section. 17. The apparatus of claim 8 or 16, characterized in that the holder (7) is designed as a carriage on which the receiving bolt (25) is attached. 18. The apparatus according to claim 16, characterized in that the receiving pin (21 or 25) is directly connected at one end to the receptacle or the holder carriage and the free end of the receiving pin in the loading direction in each case via a removable clamp (33 or 34) on the receptacle or the carriage is supported. 19. The apparatus of claim 16 to 18, characterized in that the cap (19) and / or the rod (28) of the connecting rod (20) in each case via fixing and contact elements (24 or 27) in the receptacle and the holder clamped and in contact with the receiving bolt (21 or 25) are pressed. 20. The apparatus of claim 8 and 17, characterized in that the impact mass (3) or the impact masses yoke-shaped and equipped with two impact surfaces (16) which cooperate with counter-impact surfaces (17) of the carriage, which on both sides of the receiving pin (25) are arranged on the carriage. 21. The device according to claim 8, characterized in that on the device base (1) fixed biasing cylinder (10) is provided which engages with its piston rod (11) on the holder (7) or the brackets. 22. The apparatus according to claim 8, characterized in that in the movement path of the respective holder (7) damping cylinder (8) are arranged. 23. Apparatus according to claim 8 to 22, characterized in that the weight and the speed of the impact mass or the impact masses are variable. 24. Apparatus according to claim 8 to 23, characterized in that the weight of the holder or the holders is changeable.