EP3456887B1 - Excavator boom and excavator - Google Patents

Description

The invention relates to a boom for an earth moving machine, in particular an excavator, with at least two bearing plates for mounting a cylinder unit, these running at least largely parallel to one another in the longitudinal direction of the boom.

Different boom structures are sufficiently known from the prior art, see for example JP S63 76057 U , JP 2010 106463 A as WO 99/00554 A1 . The formation of any bearing points for the connection of linear actuators is also known, these being formed, depending on the structure, in the form of two parallel bearing plates. Since the boom is relatively heavily stressed in the area of the actuator connection, the bearing plates are regularly provided with additional reinforcement plates and / or made with very large plate thicknesses. However, this measure is expensive and leads to a disadvantageous increase in the total weight of the boom.

The object of the present invention consists in the search for possible solutions to problems in the design of the bearing points for cantilever structures of the generic type.

This object is achieved by a boom according to the features of claim 1. Advantageous configurations of the boom are the subject of the dependent claims. In the context of the invention, the term boom is used comprehensively. For example, it also includes a so-called style.

According to the invention, it is proposed for the generic boom that the bearing plate (s) be designed with a curvature extending outward at the end toward the side edge of the outer boom. The invention applies both to boom designs with only one bearing plate and to such designs with two or more bearing plates. For the sake of simplicity, the invention and its advantageous embodiments are always described below using an embodiment with two bearing plates, but the following explanations apply equally to a cantilever design with only one or more than two bearing plates.

In the case of an embodiment with several bearing plates, these consequently no longer run parallel in the end section, but rather the distance between the bearing plates increases. The special curvature in the end area of the bearing plates, in particular in the end area of the bearing plates facing the boom tip, has an advantageous effect on the resulting mechanical rigidity of the boom, especially in the area of the bearing plates arranged, since the force dissipation from the bearing point into the boom can be better distributed. In this way, any reinforcement plates, as are customary in the prior art, can ideally be dispensed with. In addition, the sheet thickness of the bearing sheets can be reduced. Overall, the construction according to the invention allows a significant weight reduction. The lower expenditure of material and time in the manufacture of the boom according to the invention ensures positive cost savings.

According to the invention, at least one bearing plate or both bearing plates are guided at the end to the edge of the top side of the boom and adjoin the edge of the boom surface formed with the side faces. It is also provided here that the top side of the boom is widened in the area of the outwardly running bearing plates, ie the entire boom profile is made wider in the area of the at least one or the adjacent bearing plates so that the latter are extended beyond the original edge between the surface and the side part and on the extended boom area, ie the lateral extension of the boom are positioned. This design means that the ends of the bearing plates are less stressed.

According to a preferred embodiment, the bearing plate (s) can be fastened standing vertically on the top side of the boom.

The boom can be composed of a rear and a front boom part in a materially bonded manner to form a boomerang-like boom structure, but the invention can in principle be used for any boom structure.

It is conceivable that the bearing plates extend outwards with an identical radius of curvature in each case. However, it is also conceivable to provide individual bearing plates with different radii of curvature.

The proposed bearing plate or plates are used to support a cylinder which is used to actuate an attachment and / or a boom extension mounted on the boom. The corresponding attachment can additionally have a corresponding boom extension, a corresponding cylinder unit then being used to actuate the boom extension.

Furthermore, it is preferred if the curvature of the bearing plate or plates directly adjoins a pin receptacle of the bearing plate. Corresponding bearing plates are usually formed by a bearing plate which, in the area of the widest point, provides a suitable bore for receiving a bearing pin. The width of the bearing plates can usually be continuously reduced in the direction of the boom foot. In the direction of the boom tip, there is preferably a sudden reduction in the sheet metal width, with the bearing sheet metal reduced in width is then guided with a corresponding radius of curvature outwards to the edge of the boom surface.

The boom construction is composed of at least one front and at least one rear boom part. The bearing plate (s) can extend, for example, at least for the most part on the top side of the boom top of the front boom part. According to a preferred embodiment of the invention, at least one upper connecting plate can be provided in the connecting area between the boom parts, which ideally represents a part of the boom top in the connecting area of the boom parts. The connecting plate provides a suitable curvature depending on the angle of the two boom parts to one another. In the case of such a special construction of the boom, it is particularly advantageous if the bearing plates extend from the boom top of the front boom part to the upper connecting plate. The bearing plates, which are usually welded to the boom parts, then extend at the end into a less stressed boom area on the connecting plate. The weld seams required there are therefore subject to less stress, which has a positive effect on their resistance to fatigue. An otherwise necessary post-treatment of the weld seams could be dispensed with.

In addition to the boom according to the invention, the present invention also relates to an earthmoving machine, in particular an excavator with at least one boom according to the present invention. The advantages and properties of the earth moving machine therefore obviously correspond to the advantages and properties already discussed in connection with the excavator boom according to the invention, which is why a repetitive description is dispensed with at this point.

Figur 1:

eine perspektivische Draufsicht auf den erfindungsgemäßen Baggerausleger;

Figur 2:

eine Detailansicht der Verbindungsstelle zwischen dem vorderen und hinteren Baggerauslegerteil und

Figur 3:

eine Detailansicht des Verbindungsbereichs der Figur 2 mit geöffneter Seitenfläche des Auslegerarms.

Further advantages and properties of the invention are to be explained in more detail below on the basis of an exemplary embodiment shown in the figures. Show it:

Figure 1:

a perspective top view of the excavator boom according to the invention;

Figure 2:

a detailed view of the junction between the front and rear excavator boom part and

Figure 3:

a detailed view of the connection area of the Figure 2 with the side surface of the extension arm open.

The perspective side view of the Figure 1 shows the overall structure of the excavator boom 10 according to the invention. This consists of a front boom part 11 and a rear boom part 12. Connection points 34 are provided on the front boom part for the movable mounting of an attachment or a boom extension, not shown here. The rear boom section 12 comprises corresponding bearing points 16 at the end in order to be able to link it to an excavator superstructure or undercarriage such that it can be luffed.

Both the rear and the front boom part can be made as a monoblock. However, it is also possible to assemble the boom parts 11, 12 from individual elements.

Both boom parts 11, 12 have a box-shaped structure which is obtained by welding corresponding side plates. The individual side plates 11a to 11d or 12a to 12d are welded to one another by fillet weld welding.

The connection between the two cantilever parts 11, 12 is created by the central connecting plate 13, at least the front edges of the side plates 11a, 11b and 12a, 12b and possibly the undersides 11d and 12d being firmly connected to one another via the connecting plate 13. The connecting plate 13 has a curved shape, as a result of which a curved contact edge of the boom parts 11, 12 also extends along the side plates 11a, 11b, 12a, 12b results. The connecting plate 13 is designed as a simple, thick plate. It allows a simple connection between the boom parts 11, 12 and, accordingly, a simple adaptation to the desired angle that the two boom elements 11, 12 form. In addition, it is also possible to react flexibly to the desired width of the box-shaped bracket parts 11, 12, ie the width of the respective side surfaces 11c, 12c. The construction leads to a significant reduction in the production costs incurred and the resulting total weight of the boom 10.

In the area of the top of the boom, the boom surfaces 11c and 12c of the boom parts 11, 12 are not directly connected to one another. Instead, a plate-shaped upper connecting plate 15 is inserted or placed overlapping on the upper sides 11c, 12c, and welded to the two bracket parts 11, 12. The plate-shaped upper connecting plate 15 is bent in accordance with the angle that the two arm parts 11, 12 form with respect to one another. If necessary, the underside of the boom could also be designed with a corresponding connecting element.

In the area of the rear boom part 12, a cylindrical tube 21 extends transversely to the boom longitudinal axis through the boom box 12 and is welded onto the central connecting plate 13. The application of the bearing tube 21 to the central connecting plate 13 at the same time ensures that the overall rigidity of the boom can also be increased. A suitable bolt can be inserted into the cylinder tube 21 via outlet openings 21a, 21b within the side elements 12a, 12b. In the area of the outlet openings 21a, 21b, additional reinforcement plates 22 are also attached to the outside of the side plates 12a, 12b. The tube 21 forms the bearing point for connecting a luffing cylinder of the excavator according to the invention, which extends from the bearing point 21 of the rear boom part 12 to the upper carriage of the excavator.

For the storage of a further hydraulic adjusting means in the form of a hydraulic cylinder, there is an additional bearing point on the upper side of the boom 10 30 is provided, which enables a cylinder to be received, which extends from the bearing point 30 to an attachment that is received at the bearing point.

The bearing point 30 consists of two parallel bearing plates 30a, 30b, which are perpendicular to the top side of the boom and run parallel in the longitudinal direction of the boom. In the area with the greatest width, a respective bore 31a, 31b is provided for receiving bolts, the edge of the bore being reinforced with additional metal sheets 32. The width of the bearing plates 30a, 30b decreases steadily in the direction of the rear boom part 12. The majority of the bearing plates including the bores 31a, 31b is arranged on the upper side 11a of the front boom part 11, but both plates 30a, 30b extend parallel to the upper connecting plate 15, to which the plate ends are welded. The extension of the bearing plates 30a, 30b up to the connecting plate 15 has the advantage that the end of the weld seam that is formed lies in a region of the boom that is less stressed by force, which not only increases the fatigue resistance, but also enables manufacturing costs to be reduced If no additional treatment of the weld seam is necessary.

It can also be seen that the width of the bearing plates 30a, 30b decreases abruptly after the bore 31a, 31b in the direction of the boom tip and then remains almost constant. These bearing plate sections 33a, 33b with a reduced but almost constant width have a curvature so that the plate sections 33a, 33b do not protrude parallel to one another, but rather outwardly to the edges of the surface 11c of the front boom part 11.

The upper plate 11a of the front boom part 11 can be widened in the area of the bearing plate sections 33a, 33b adjoining the edge, so that the sheet metal elements 33a, 33b can protrude beyond the actual edge of the front boom part. By bending the bearing plates 30a, 30b, the overall rigidity of the bearing can be increased, but without the strength of the bearing plates 30a, 30b to have to increase. In addition, it is also not necessary to attach additional reinforcement plates in the area of the bearing point. This allows the total weight of the boom to be further reduced and its manufacture to be further simplified.

Claims (12)

1. A boom (10) for an earth-moving machine, in particular an excavator, comprising one or more bearing plates for supporting a cylinder unit, characterized in that
   at least one bearing plate (30a, 39) has an end-side curvature (33a, 33b) extending outwardly to a lateral edge of the boom; in that a boom upper side is broadened in a region of the outwardly running bearing plate or plates; and in that the bearing plate or plates extend up to the broadened boom upper side.
2. A boom in accordance with claim 1, characterized in that, in the case of at least two bearing plates, they extend at least to a greater extent in parallel with each other in a longitudinal direction of the boom.
3. A boom in accordance with claim 1 or claim 2 , characterized in that at least one bearing plate is fastened standing perpendicular to the boom upper side, with the boom preferably being assembled with material continuity from a rear boom part (12) and a front boom part (11) to form a boomerang-like boom structure.
4. A boom in accordance with one of the claims 1 to 3, characterized in that a plurality of bearing plates each extend outwardly with an identical radius of curvature.
5. A boom in accordance with one of the preceding claims, characterized in that the bearing plate or plates are provided for supporting a cylinder for actuation of an attachment and/or of a boom extension.
6. A boom in accordance with one of the preceding claims, characterized in that the end region of the bearing plate or plates extending to a boom tip has the curvature.
7. A boom in accordance with one of the preceding claims, characterized in that the plate region of the bearing plate or plates directly adjoining a bolt receptacle (31a, 31b) extends outwardly.
8. A boom in accordance with one of the preceding claims, characterized in that the bearing plate or plates extend at least to a greater extent on the boom upper side of the front boom part.
9. A boom in accordance with one of the preceding claims, characterized in that the front and rear boom parts are at least regionally directly connected to each other and in addition a connection between the front and rear boom parts is provided by means of at least one upper connecting plate (15), with the bearing plate or plates extending from the boom upper side of the front boom part up to the connecting plate, and with the bearing plate or plate ideally ending at the upper connecting plate.
10. A boom in accordance with claim 9, characterized in that the width of the bearing plate or plates reduces from the bolt receptacle in the direction of the rear boom part, in particular decreases constantly in this direction.
11. A boom in accordance with one of the preceding claims, characterized in that the width of the bearing plate or plates decreases abruptly after the bolt receptacle in the direction of the boom tip.
12. An earth-moving machine, in particular an excavator, having at least one boom in accordance with one of the preceding claims.

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