STICK FOR AN EXCAVATOR

Description

The invention relates to a stick for an excavator, on which a mounting device with a coupling device is arrangeable on the stick so as to pivot about an mounting axis.

DE 20 2011 100 482 U1 discloses an excavator which, at the free end of the stick, pivotably accommodates an mounting device which is pivotably connected to a coupling device of the mounting device about an mounting axis on the stick. A swivel drive is provided on the coupling device, which in turn has a coupling opposite the coupling device for holding an working tool. A pressure cylinder is provided on an upper side of the stick to control a swivel movement of the mounting device around the mounting axis of the stick. A piston rod of the pressure cylinder engages with a swivel kinematic systick. This swivel kinematics comprises a coupling and a deflector, which are pivotably arranged in a common axis on which the pressure cylinder engages, the deflector engaging at the opposite end in a deflector axis of the stick and the coupling engaging with the opposite end on the coupling device. An upper side and an lower side of the stick are tapered in the direction of the mounting axis. The design of such a stick with a connection of the attachment to the attachment axle arranged at the end of the stick enables a wide range of applications. However, there are applications in which the pivoting movement of the attachment to the stick is not sufficient.

The invention is based on the task of creating a stick for an excavator in order to reduce a breakaway force from an attachment to a stick.

This task is solved by a stick for an excavator, in which a fork-shaped connection is provided between the stick and the mounting device and/or between the swivel kinematics and the mounting device. This fork-shaped connection enables the mounting device to be positioned closer to an mounting axis on the stick. In addition, this fork-shaped connection allows the mounting device to be positioned closer to the basic machine. As a result, the distance between the attachment and the stick can be reduced. This makes it possible to shorten the acting lever arms and leads to a reduction in the breakaway force. This can also enable improved handling and an increased swivel range of an working tool around the mounting axis at the stick end of the stick.

It is preferably provided that a distance of the attachment bearing point of the coupling device to an end face or an flattening of the mounting device and/or a distance of the coupling bearing point of the coupling device to a cover surface of the mounting device is equal to or less than 2.5 times a bolt diameter of the attachment bearing point and/or the coupling bearing point of the coupling device. This has the advantage that the acting lever arms between the working tool and the stick are shortened. This can also reduce the breakaway force. At the same time, the process forces can also be increased.

According to a first embodiment, it is preferably provided that the fork-shaped connection between the stick and the mounting device is formed by a fork-shaped stick section pointing towards the end of the stick, which has two fork arms arranged at a distance from each other. This design of the fork-shaped stick section allows a part of the mounting device to be positioned between the two fork arms for connection to the end of the stick.

It is preferable that the attachment axis and the deflector axis are provided in the fork arms of the fork-shaped stick section. This allows for a compact and shortened arrangement to accommodate the mounting device and/or the swivel kinematics.

The fork-shaped stick section can be designed as a straight stick section. A straight stick section can be understood to mean a connection of the stick section to the main stick section, in which the top and/or bottom of the stick section and the main stick section lie in a common plane. Alternatively, it may be provided that the fork-shaped stick section is cranked relative to the main stick section. In the case of an offset arrangement of the stick section relative to the main stick section, the cranked stick section is oriented upwards at an angle relative to the main stick section.

In the embodiment with the fork-shaped stick section, it is preferable that a deflector is positioned on the inside of each fork arm and is mounted on the deflector axis in the fork arm. The coupling is preferably rod-shaped and preferably engages between two cheeks of the coupling device. As a result, the swivel range towards the top of the stick can be further increased.

According to an alternative embodiment, it is provided that the fork-shaped connection between the swivel kinematics and the mounting device comprises a fork-shaped coupling with two coupling arms, whereby the coupling arms are connected to the coupling device in an articulated manner. Preferably, a coupling stick can be formed opposite the coupling arms.

The swivel kinematics, which preferably comprises the fork-shaped coupling, can be provided on a fork-free stick section that is aligned with the end of the stick. A fork-free stick section can be understood to mean that the stick section and the main stick section form a unit and, for example, the side cheeks and/or the upper and/or lower side lie in one plane. This embodiment with the fork-free stick end and the fork-shaped coupling of the swivel kinematics has the advantage that the mounting device can in turn be shortened in the connection to the stick. This also enables an increased swivel angle.

Preferably, the fork-shaped coupling of the swivel kinematics engages with each coupling arm on an outer side of the cheeks of the coupling device. Alternatively, the coupling arms can also be aligned with an inner side of the cheeks.

In the design of the fork-free stick section at the end of the stick, a deflector preferably engages on the deflector axis of the stick section on each outer side of the stick section, whereby the deflector is preferably mounted opposite on each outer side of the coupling to the swivel axis. This can result in an increased swivel movement of the swivel kinematics.

The fork-free stick section, on which the swivel kinematics with the fork-shaped coupling is preferably provided, can be straight in relation to the main stick section. An upper side and/or an lower side of the stick section and the main stick section can lie in one plane. Alternatively, the fork-free stick section can be cranked in relation to the main stick section. In the case of a cranked stick section, this can be angled at an angle of less than 180° to the upper side of the main stick section. With regard to the straight and cranked design, reference can be made to the above explanations.

Furthermore, it is preferably provided that a coupling device of the mounting device is pivotably connected to an attachment pin in the mounting axis of the stick section and a coupling pin is provided on the coupling device, on which a coupling of the swivel kinematics engages, wherein the swivel kinematics has a deflector which engages on the deflector axis of the stick and the swivel kinematics is pivotably actuated by the pressure cylinder. The coupling and the deflector of the swivel kinematics are matched to each other in such a way that when the attachment is swiveled to the top of the stick, the coupling pin of the coupling device can be arranged adjacent to the deflector axis of the stick. By connecting the attachment to the cranked stick, an increased swivel range can be achieved.

Furthermore, it is preferable for the attachment bolt and the coupling bolt of the coupling device to be offset in height in relation to each other and preferably for the attachment bearing point to be offset in the direction of a rotary drive of the mounting device. As a result, the coupling bolt can be located above the rotary drive and the attachment bearing point can be offset, i.e. recessed, in the direction of the rotary drive.

Furthermore, it is preferably provided that the attachment bearing point and the coupling bolt of the coupling device are arranged at an angle to the mounting device which is formed by two fictitious straight lines, wherein the first or the one fictitious straight line extends through the attachment bearing point and the coupling pin and the second or the other fictitious straight line extends offset in a plane of rotation or parallel to a plane of rotation of a rotary device of the mounting device. Due to this offset arrangement of the coupling bolt and the attachment bearing point of the coupling device, the attachment bearing point of the coupling device can be offset in the direction of the plane of rotation of the rotary device of the mounting device, which makes it possible to reduce the installation height of the mounting device relative to the stick. In particular, this increases the swivel angle range to the lower side of the stick.

Advantageously, the fictitious straight lines of the mounting device are provided at an angle β of 15° to 45°, preferably 25° to 35°. This in turn enables an advantageous connection of the mounting device to the cranked stick section of the stick.

Advantageously, it is provided that the cranked stick section lies at an angle a between two fictitious straight lines, the first or one fictitious straight line extending through the mounting axis and the deflector axis and the second or the other fictitious straight line extending through the deflector axis and a stick connection axis of the stick or the one fictitious straight line extends through the mounting axis and the deflector axis and the second or the other fictitious straight line extends through the deflector axis and a stick mounting axis of the stick. This area at the stick end is sufficient to form the cranked stick section in order to increase the swivel angle range of the mounting device.

Preferably, the cranked stick section is angled at an angle a of 15° to 45°, preferably at an angle α of 25° to 35°, towards the top of the stick. This range has proven to be advantageous for the use and connection of the mounting device.

It is preferable that the angular range of the fictitious straight line of the mounting device and the angular range of the fictitious straight line on the cranked stick section are the same. This allows the largest swivel range or the largest opening angle to be achieved. This opening angle can be 200°, within which the mounting device can be pivoted to the cranked stick section.

Preferably, the height between the coupling bolt and the attachment bearing point of the coupling device on the one hand and the height between the mounting axis on the cranked stick section and the deflector axis on the stick on the other hand are the same.

A deflector axis for the swivel kinematics is preferably provided in the transition area between the main stick section and the cranked stick section. Alternatively, it is also possible for the deflector axis to be provided in the cranked stick section, i.e. outside the transition area between the main stick section and the cranked stick section. Alternatively, the deflector axle can also be provided in the stick.

Furthermore, it is preferably provided that the length of the stick section has a length of less than 20% in relation to the overall length of the stick. Preferably, the length of the cranked stick section extends from the deflector axis to the free end of the cranked stick section. This cranked and short stick section may be sufficient to increase the pivoting mobility.

The invention and other advantageous embodiments and further embodiments thereof are described and explained in more detail below with reference to the examples shown in the drawings. The features to be taken from the description and the drawings can be used individually or in any combination in accordance with the invention. It shows:

FIG. 1 a schematic side view of an excavator with a stick, a mounting device and a working tool,

FIG. 2 a schematic side view of a stick for an excavator with a cranked stick section,

FIG. 3 a perspective view of the stick as shown in FIG. 2,

FIG. 4 a perspective view of a mounting device for connection to the stick as shown in FIG. 2,

FIG. 5 a schematic side view of the mounting device as shown in FIG. 4,

FIG. 6 a schematic sectional view of the mounting device along line IV-IV in FIG. 4,

FIG. 7 a perspective view of the stick according to FIG. 2 with a mounting device according to FIG. 4 in a working position,

FIG. 8 a schematic side view of the stick according to FIG. 3 with a mounting device according to FIG. 4 in a first working position,

FIG. 9 a schematic side view of the arrangement shown in FIG. 6 in a further working position,

FIG. 10 a perspective view of an alternative embodiment of the stick to FIG. 3,

FIG. 11 a perspective view of the stick according to FIG. 9 with a mounting device according to FIG. 4 in a working position,

FIG. 12 a perspective view of an alternative embodiment of the stick to FIG. 3,

FIG. 13 a perspective view of the stick according to FIG. 11 with a mounting device according to FIG. 4 in a working position,

FIG. 14 a perspective view of an alternative embodiment of the stick to FIG. 11, and

FIG. 15 a perspective view of the stick according to FIG. 13 with a mounting device according to FIG. 4 in a working position.

FIG. 1 shows a schematic side view of an excavator 11. The excavator 11 comprises a basic machine 13 with a boom 12, which is hinged together at the end with a stick 14. The boom 12 is moved up and down by a lifting cylinder 19. The boom 12 comprises at least one stick cylinder 18 for actuating a pivoting movement of the stick 14. A pressure cylinder 16 is provided on the stick 14, at least, by means of which an mounting device 21 provided on the stick 14 can be actuated. The mounting device 21 is pivotably mounted at the end of the stick 14 in an mounting axis 17. This mounting device 21 can comprise a rotary device 22 with a rotary drive 24 and a coupling 23, in particular a quick-change coupling. The rotary device 22 comprises a drive housing 66. The rotary drive 24 allows the coupling to rotate relative to the drive housing 66 along an axis of rotation 26. An working tool 25 is interchangeably provided on the coupling 23. Swivel kinematics 27 are provided to control a swivel movement of the mounting device 21. This comprises a deflector 28, which is articulated at one end on a deflector axis 29 to the stick 14. Furthermore, the swivel kinematics 27 comprises a coupling 31, which is connected at one end to the deflector 28 via a common swivel axis 35. At the opposite end, the coupling 31 engages with a coupling device 33. This coupling device 33 is a component of the mounting device 21 or is mounted on the mounting device 21. Preferably, the drive housing 66 has a cover surface 67 extending at least in sections, on which the coupling device 33 is provided. The pressure cylinder 16, in particular a piston rod of the pressure cylinder 16, engages on the swivel axis 35 of the swivel kinematics 27.

FIG. 2 shows a schematically enlarged side view of the stick 14. FIG. 3 shows a perspective view of the stick 14 as shown in FIG. 2.

The stick 14 has a stick main section 50. At one end of the stick main section 50 is a stick bearing point 41, through which the stick 14 is articulated to the boom stick 12. Adjacent to this is a stick cylinder axis 42, in which the stick cylinder 18 of the boom stick 12 engages. An lower side 43, which is designed as a lower chord, extends from the stick bearing point 41 to the front end 48 of the stick. Opposite, the stick 14 comprises an upper side 45, which is designed as an upper chord. A pressure cylinder bearing 46 for holding the pressure cylinder 16 is provided on the upper side 45. The upper side 45 and the lower side 43 are aligned at an acute angle to each other in the direction of the deflector axis 29.

The stick 14 has a cranked stick section 51. This cranked stick section 51 is provided at the stick end 48. The stick 14 comprises a main stick section 50 with the stick bearing points 41 and 42 and the cranked stick section 51. The mounting axis 17 is provided in the cranked stick section 51. The cranked stick section 51 extends from the deflector axis 29 in the direction of the upper side 45 of the stick 14. The cranked stick section 51 is cranked upwards at an angle α of, for example, 30° to the lower side 43 of the stick 14. The angle for the cranking of the stick section 21 is determined by two fictitious straight lines 52, 53. The straight line 52 extends through the mounting axis 17 and the deflector axis 29 of the cranked stick section 51. The straight line 52 extends through the deflector axis 29 and preferably runs parallel to the lower side 43 of the stick 14. The straight line 53 can also extend through the deflector axis 29 and the stick bearing point 41.

The length of the cranked stick section 51 can be determined from the angle α and a height HS between the mounting axis 17 and the deflector axis 29. The distance between the mounting axis 17 and the deflector axis 29 comprises the height HS.

The cranked stick section 51 is the same width as the main section 50 of the stick 14. In the case of very long sticks 14, the main stick section 50 can taper towards the cranked stick section 51. The width of the cranked stick section 51 and the distance between the cheeks 36 of the coupling device 33 are adapted to each other.

FIG. 4 shows a perspective view of the mounting device 21. FIG. 5 shows a schematic side view of the mounting device 21 as shown in FIG. 4.

The coupling device 33 comprises two cheeks 36 arranged at a distance from one another. The cheeks 36 can be connected to at least one connecting plate 34, which extends between the cheeks 36. The at least one connecting plate 34 can rest against an upper side of the rotary device 22 and preferably be detachably fastened thereto. A connection level 65 is formed between the upper side of the rotary device 22, to which the coupling device 33 is attached, and the coupling device 33, in particular the connecting plate 34 of the coupling device 33. Each cheek 36 comprises a coupling bearing point 37 and a attachment bearing point 38.

The coupling bearing point 37 and the attachment bearing point 38 are offset from one another in height HK. The add-on storage location 38 is recessed relative to the coupling storage location 37. The attachment bearing point 38 of the coupling device 33 lies, for example, in the connection level 65. Alternatively, the attachment bearing point 38 can also be offset in the direction of a plane of rotation 39 of the rotary device 22 or lie in this plane of rotation 39. The attachment bearing point 38 is offset laterally outwards relative to the mounting device 21, in particular the rotary device 22, or is assigned to an end face of the rotary device 22.

Between the connection level 65 of the mounting device 21 and the coupling bearing point 37, a distance HA is preferably provided which is equal to or less than or smaller than 2.5 times the diameter of a bearing pin of the coupling bearing point 37. Preferably, the coupling bearing point 37 is provided adjacent to the connection level 65. Furthermore, it may be provided that the attachment bearing point 38 is positioned at a distance HB from the mounting device 21 which is equal to or smaller than 2.5 times the diameter of a bearing bolt of the attachment bearing point 38. Preferably, the bearing pins of the coupling bearing point 37 and the attachment bearing point 38 have the same diameter. In particular, it is provided that the attachment bearing point 38 is adjacent to an end face of the rotary drive 24 or adjacent to a flattening 69, which is adjacent to an end face of the rotary drive 24. The distances HA and/or HB are preferably the same, which enables a reduction of the lever arms and thus reduces the breakaway force between the stick and the tool. Breakaway force is understood to be, for example, a force that is required to overcome static friction in a bearing and that initiates the transition to sliding friction. The breakaway force is therefore the force required to transform a bearing from a static to a dynamic state.

The height HK between the coupling bearing point 37 and the attachment bearing point 38 may be the same as the distance HA or may differ from each other.

The coupling bearing point 37 and the attachment bearing point 38 are arranged at an angle β to the plane of rotation 39, which is determined by two fictitious straight lines 56, 57. The fictitious straight line 56 extends through the coupling bearing point 37 and the attachment bearing point 38. The fictitious straight line 57 extends through the plane of rotation 39 or is aligned parallel to it. This can also be located in the at least partially formed cover surface 67 of the drive housing 66 of the rotary device 22. The attachment bearing point 38 can be located on the straight line 57 or lower in the direction of the plane of rotation 39, preferably within a height formed by the straight line 57 and the plane of rotation 39. Preferably, the angle β between the straight lines 56, 57 is provided in a range from 15° to 60°. In particular, an angle β of 30° is provided. This angle β preferably corresponds to the angle α.

FIG. 6 shows a schematic sectional view along line VI-VI as shown in FIG. 4. The rotary device 22 has a flattening 69 between the upper side or the connection level 65 and an end face 68 of the rotary device 22. This flattening 69 can, for example, be flatteningd at an angle of 45° to the connection level 65. The flattening 69 can also be provided at an angle to the connection level 85. In particular, this flattening 69 can enable the mounting point 38 of the cheeks 36 to be offset closer to the rotary device 22 and/or downwards relative to the connection level 65. This arrangement has the particular advantage that a reduced introduction of force from the stick 14 into the mounting device 21 is possible, whereby shearing forces acting on the coupling device 33 of the mounting device 21 can be reduced during operation.

The coupling device 33 is preferably connected to the rotary device 22 by a screw connection 83. In particular, one or more connecting plates 34 are in contact with the upper side of the rotary device 22 and with the flattening 69 of the rotary device 22 and are fixed in particular by the screw connection 83. This detachable arrangement of the coupling device 33 to the rotary device 22 also enables increased flexibility due to a possible replacement of the coupling device 33 to the rotary drive 24 and the coupling 23.

By reducing the installation height of the mounting device 21, which can be achieved in particular by moving the attachment bearing point 38 into the connection level 65 or below it in the direction of the plane of rotation 39, the kinematics of the stick 14 and the mounting device 21 are improved to the extent that an overload height and/or a breakaway force can be increased. This is particularly the case if the attachment bearing point 38 is located in the plane of rotation 39.

The mounting device 21 according to FIGS. 4 to 6 also has the advantage that the integration of the rotary drive 24 and the coupling 23 makes it possible to reduce the number of hydraulic connections for controlling an working tool 25. For example, the number of connections in the coupling 23 can be reduced from five connections to three connections. Two of the connections serve a main function, namely a supply and a return of the working fluid, in particular hydraulic oil. The third connection is intended for a so-called leakage oil. The connection or integration of the coupling 23 into the rotary actuator 24 enables the hydraulic connections required for the rotary actuator for control to be provided within the rotary actuator 24 and/or the coupling 23 and permanently connected to each other.

FIG. 7 shows a perspective view of the stick 14 as shown in FIG. 3 and the hinged mounting device 21 as shown in FIG. 4. The fork-shaped connection 20 is provided between the swivel kinematics 27 and the mounting device 21. The swivel kinematics 27 comprises two deflectors 28, which are each positioned on an outer side of the stick section 51 and are mounted in the deflector axis 29. These deflectors 28 engage opposite each other on the swivel axis 35 of the swivel kinematics 27. The coupling 31 of the swivel kinematics 27 is fork-shaped. The coupling 31 has two coupling arms 64 pointing towards the mounting device 21. These coupling arms 64 preferably each engage on an outer side of the cheek 36 of the coupling device 33. The respective ends of the coupling arms 64 are pivotably mounted at the coupling bearing point 37, preferably by a pin. Opposite the coupling arms 64, the coupling 31 comprises, for example, a coupling stick 65. The width of this coupling stick 65 is narrower than the distance between the two coupling arms 64. The coupling stick 65 can comprise a recess, so that a piston rod of the pressure cylinder 16 can be positioned in between and engages on the pivot axis 35.

The height HK of the coupling bearing point 37 and the attachment bearing point 38 of the coupling device 33 advantageously corresponds to the height HS on the cranked stick section 51, which is formed by the distance between the mounting axis 17 and the deflector axis 29. The cranked stick section 51 is positioned between the cheeks 36. The mounting axis 17 of the cranked stick section 51 is aligned with the attachment bearing point 38, so that these are pivotably connected to one another by a bearing pin.

In this embodiment, for example, the deflectors 28 are straight. This allows higher forces to be absorbed. This embodiment is preferably used for compact excavators or medium-sized or large excavators. In the embodiment shown in FIGS. 8 and 9, the deflectors 28 are c-shaped or curved. This embodiment is preferably used with mini excavators.

FIG. 8 shows a schematic side view of the stick 14 with the mounting device 21 in a first swivel or working position. In FIG. 9, the stick 14 with the mounting device 21 is shown in a further swivel or working position that differs from the arrangement in FIG. 7.

The stick 14 with the cranked stick section 51 enables the mounting device 21 to be pivoted at a pivoting angle A of up to 60° relative to the fictitious straight line 53 in the direction of the lower side 43 of the stick 14. Due to the offset arrangement of the attachment bearing point 38 relative to the coupling bearing point 37 and the cranked stick section 51, the rotary device 22 can be positioned almost parallel or parallel to the fictitious straight line 52 with respect to its axis of rotation.

FIG. 9 shows the further swivel position of the mounting device 21 in the opposite direction to that in FIG. 8. A swivel angle B of up to 160° can be assumed relative to the fictitious straight line 53 through the deflector axis 29. This swivel position can be assumed by the cranked stick section 51. This results in a swivel angle of the mounting device 21 of up to 220° to the cranked stick section 51.

FIG. 10 shows an alternative embodiment of the stick 14. The stick section 51 is not bent in relation to the main stick section 50. Such a stick 14 is referred to as a straight stick. It is provided that an upper and/or lower side of the stick section 51 and the main stick section 50 lie in a common plane. In all other respects, the explanations relating to the aforementioned stick 14 apply.

FIG. 11 shows a perspective view of the stick 14 according to FIG. 10 and the mounting device 21 according to FIG. 4. A swivel movement of the mounting device 21 relative to the stick 14 is controlled using swivel kinematics 27, which corresponds to the embodiment shown in FIG. 7. A fork-shaped coupling 31 is used. This embodiment therefore comprises a fork-shaped connection 20 between the swivel kinematics 27 and the mounting device 21.

FIG. 12 shows an alternative embodiment of the stick 14 as shown in FIGS. 2 and 3. The stick 14 has an cranked stick section 51 towards the main stick section 50. In contrast to the embodiment according to FIGS. 2 and 3, the cranked stick section 51 according to FIG. 12 is fork-shaped. The cranked stick section 51 comprises two fork arms 61, which are spaced apart from one another. The deflector axis 29 and the mounting axis 17 are provided in each fork arm 61. Preferably, the distance between the fork arms 61 in the area in which the deflector axis 29 is provided is smaller than in the section pointing towards the free end 48 of the stick in which the mounting axis 17 is located. This has the advantage that analogous or the same ratios exist for connecting the mounting device 21 to the stick 14 as in the embodiment according to the stick in FIGS. 2 and 3 and in FIG. 9.

FIG. 13 shows a perspective view of the stick 14 according to FIG. 12 with the mounting device 21 according to FIG. 4 in a swivel position. The fork-shaped connection 20 is formed between the stick 14 and the mounting device 21. In this embodiment, the swivel kinematics 27 has a coupling 31 which is, for example, rod-shaped. Alternatively, it can also be provided that in this embodiment according to FIG. 12, the coupling 31 can also be designed as a fork-shaped coupling 31 with two coupling arms 64. Preferably, the coupling 31 can be designed as a welded construction in which two rod-shaped metal sheets are connected to a web, preferably also made of sheet metal, the rod-shaped metal sheets engaging both on the pivot axis 35 and on the coupling bearing point 37. Alternatively, the welded construction can also be designed as a cast construction.

FIG. 14 shows an alternative embodiment of the stick 15 to FIG. 11. This embodiment differs from that in FIG. 11 in that the stick section 51 is straight in relation to the main stick section 50. An offset of the stick section 51 is not provided. In all other respects, the comments on FIG. 12 apply.

FIG. 15 shows a perspective view of the stick 14 as shown in FIG. 14 and the mounting device 21 as shown in FIG. 4 in a working position. In this embodiment, the swivel kinematics 27 are designed in the same way as in FIG. 12. A fork-shaped coupling 31 can also be provided as an alternative in this respect.