LOCKING DEVICE FOR A SIDE STABILIZER OF A THREE-POINT POWER LIFT

Description

[0001] The invention relates to a locking device with a side stabilizer and a bracket that can be attached to a three-point linkage, wherein the side stabilizer is pivotably attached to the bracket by means of a bearing bolt.

[0002] These side stabilizers, depending on the operating position of a three-point linkage on an agricultural tractor, allow lateral movement of the lower link of the three-point linkage to be blocked in a raised transport position or, conversely, permitted to a certain extent in a lowered working position. For this purpose, the side stabilizer is attached at one end to a bracket mounted at the rear of the agricultural tractor and at the other end to the lower link of the three-point linkage. More precisely, the three-point linkage has left and right lower links for attaching the corresponding agricultural implement, with each of the two lower links generally having its own separate side stabilizer.The lower links can be pivoted between the raised transport position and the lowered working position by means of a hydraulic lifting mechanism at the request of an operator.

[0003] Such a side stabilizer is known, for example, from DE 602 00 422 T2. The side stabilizer comprises a first and a second stabilizer element, the two stabilizer elements being mechanically coupled to each other in such a way that they can move relative to each other along a common longitudinal axis. A locking flap pivotally attached to the first stabilizer element serves to longitudinally lock the two stabilizer elements depending on the operating position of the three-point linkage. For this purpose, a recess provided in the locking flap can engage with a projection formed on the second stabilizer element. Depending on the position of the locking flap, lateral movement of a lower link attached to the side stabilizer can therefore either be completely prevented or allowed within the limits of the side stabilizer's design.

[0004] In addition, there are hydraulically controlled side stabilizers in which the mechanical coupling of the two stabilizer links is achieved by means of a hydraulic cylinder. The design of such a side stabilizer is described in EP 3 721 690 A1. Accordingly, the hydraulic cylinder has a cylinder chamber that can be pressurized with hydraulic fluid via a hydraulic connection, allowing a longitudinally displaceable piston to be moved into a fully extended position. If each of the two lower links has its own side stabilizer, this allows the lower links to be braced against each other in a centered position when an implement is attached. This prevents unwanted lateral movements of the implement in the raised transport position.In contrast, when pressure is released, the piston can move freely within the cylinder chamber, which makes it possible to perform lateral compensating movements of the implement in the lowered working position during field work.

[0005] Especially when performing transport operations with a towed trailer, achieving the smallest possible turning circle requires that the lateral freedom of movement of the drawbar mounted at the rear of the agricultural tractor is not obstructed by adjacent components of the three-point linkage. In such cases, it is therefore common practice to completely remove the lower links. However, this also necessitates the removal of the stabilizer bars, which, if they are hydraulically controlled, is comparatively time-consuming due to the hydraulic connections that then need to be disconnected.

[0006] Other known locking devices are described in US 2007 / 209810 A1, DE 43 10 027 C1 and JP S52 109103 U.

[0007] It is therefore an object of the present invention to provide a locking device of the type mentioned above for the purpose of simplifying the removal of the lower links. This object is achieved by a locking device with the features of claim 1.

[0008] The inventive locking device is defined in claim 1.

[0009] In this case, disassembly of the side stabilizer with the lower link removed is unnecessary; it can remain on the three-point linkage after being moved into the designated rest position. The rest position is chosen so that the side stabilizer does not obstruct any lateral movement of a drawbar attached to the rear of the agricultural tractor.

[0010] Advantageous further developments of the locking device according to the invention are set out in the dependent claims.

[0011] The bracket can have first and second side plates that engage a mounting joint provided on the side stabilizer, with the bearing bolt extending through both side plates and the mounting joint for pivoting the side stabilizer. The bracket is, for example, a U-shaped sheet metal component made of sheet steel, which can be attached to a mounting interface of the three-point linkage by means of several threaded screws via a cross piece connecting the two side plates. The two side plates run parallel to each other, with the bearing bolt and retaining bolt inserted through aligned bores and secured therein by means of corresponding shaft retainers.

[0012] For the purpose of convenient handling of the side stabilizer, the locking mechanism according to the invention has a spring-loaded catch hook for releasable engagement of a retaining bolt provided on the bracket.

[0013] In this case, the locking mechanism can be a captive component of the side stabilizer.

[0014] Furthermore, the side stabilizer, as part of the locking mechanism, can have a recess that opens in the pivoting direction to positively engage the contact contour of the retaining bolt, whereby the retaining bolt can be secured within the recess by means of the catch hook. The recess can extend into a locking housing that is integrally formed on the upper side of the side stabilizer. The positive engagement between the contact contour and the recess is achieved taking into account a bearing clearance provided for reasons of contamination tolerance.

[0015] In addition, an actuating element may be present for manually deflecting the catch hook into a position that releases the recess. This actuating element may, in particular, be designed as a handle protruding from the locking housing, which can be manually operated against a spring preload acting on the catch hook to unlock the locking mechanism.

[0016] Additionally, the catch hook can have a ramp-shaped actuating section such that, when the side stabilizer pivots towards its predetermined rest position, the retaining bolt pushes the catch hook away into a position that releases the recess. The locking mechanism thus forms a snap lock, in which the spring-loaded catch hook automatically returns to its initial position while locking the side stabilizer, as soon as the retaining bolt has assumed its final position within the recess.

[0017] The side stabilizer can be angled upwards in its designated rest position relative to the installation position intended or specified for operation on the three-point linkage. This largely prevents unwanted contact between a drawbar attached to the rear of the agricultural tractor and the side stabilizer.

[0018] The locking device according to the invention for a side stabilizer of a three-point linkage is described in more detail below with reference to the accompanying drawings. Identical reference numerals refer to identical or functionally comparable components. The drawings show: Fig. 1 a three-point linkage on an agricultural tractor, comprising a locking device according to the invention for a side stabilizer, Fig. 2 the in Fig. 1 The side stabilizer shown is in a predetermined rest position, and Fig. 3a shows a step-by-step locking sequence when pivoting the in Fig. 1 The side stabilizer shown is placed in the specified resting position.

[0019] Fig. 1 shows an embodiment of the locking device according to the invention.

[0020] The locking device 10 comprises a side stabilizer 12 and a bracket 14, on which the side stabilizer 12 is pivotably attached by means of a bearing bolt 16 about a pivot axis 18 running transversely to the bracket 14.

[0021] For example, the bracket 14 has first and second side plates 20, 22 which run parallel to each other and engage a mounting joint 26 provided on the side stabilizer 12 or a first stabilizer link 24, wherein the bearing bolt 16 for pivoting the side stabilizer 12 extends through the two side plates 20, 22 and the mounting joint 26, more precisely through a ball joint 30 mounted in a mounting eye 28 of the mounting joint 26 (see [reference]). Fig. 3 ac ).

[0022] The bracket 14 is a U-shaped sheet metal part made of sheet steel, which is attached to a mounting interface 38 of a three-point linkage 42 of an agricultural tractor 40 by means of several threaded screws 34, 36 via a cross piece 32 connecting the two side plates 20, 22. Only a section of the chassis structure of the agricultural tractor 40 is shown here. The mounting interface 38 is designed as a flat mounting flange 44 on a lower surface 46 of an axle housing 48 (indicated by dashed lines). The axle housing 48 contains a reduction drive for operating a rear wheel (not shown) of the agricultural tractor 40 and is itself connected to a differential housing 50 of the agricultural tractor 40.

[0023] Furthermore, the side stabilizer 12 is attached to a mounting leg 56 of a lower link 58 by means of a fork-shaped mounting end 52 of a second stabilizer element 54, the mounting leg 56 projecting laterally from the lower link 58. The fork-shaped mounting end 52 is attached to the mounting leg 56 by means of a locking bolt 60 such that a joint rotatable transversely to the longitudinal extent of the lower link 58 is formed.

[0024] The three-point linkage 42 located in the rear area 62 of the agricultural tractor 40 comprises symmetrically arranged left and right lower links 58, of which in Fig. 1Due to the illustration, only the right-hand link (viewed in the forward direction 64) is visible. Each of the two lower links 58 is assigned a separate side stabilizer 12 and a separate locking device 10. The lower links 58 can be pivoted between a raised transport position 70 and a lowered working position 72 by means of a hydraulic lifting mechanism 66 via an associated lifting arm 68 at the operator's command. At one outer end 74 of the lower link 58 is a coupling hook 76, which serves for the detachable attachment of a complementary lower coupling element 78 of an implement interface encompassed by an agricultural implement. A top link (not shown) further allows the attachment of a central upper coupling element present at the implement interface.

[0025] The side stabilizer 12 is hydraulically controllable, for which purpose the two stabilizer sections 24 and 54 are mechanically coupled to each other via a hydraulic cylinder 80 enclosed by the side stabilizer 12. The first stabilizer section 24 is a structural component of a stabilizer housing 82, which contains a (not visible) cylinder chamber that can be pressurized with hydraulic fluid via a hydraulic connection 84. The second stabilizer section 54 transitions into a piston 86 that is longitudinally displaceable within the cylinder chamber. A high-pressure line 88, communicating with the hydraulic connection 84, allows the piston 86 to be moved to a fully extended position within the cylinder chamber at the instigation of a tractor-side hydraulic system.Since each of the two lower links 58 has its own side stabilizer 12, the lower links 58 can be braced against each other in a centered position when the implement is attached. This prevents unwanted lateral movements of the implement in the raised transport position 70. When the pressure is released, however, the piston 86 can move freely within the cylinder chamber, allowing the implement to make lateral compensating movements in the lowered working position 72 during fieldwork. The switch between this locked and floating state occurs automatically, depending on the position of the hydraulic lift mechanism 66 detected by a sensor.

[0026] As in Fig. 1As can be seen, the locking device 10 has a locking mechanism 90 with a spring-loaded catch 92 for the releasable engagement of a retaining bolt 94 provided on the bracket 14. The retaining bolt 94, like the bearing bolt 16, is inserted through aligned bores 96, 98 within the side walls 20, 22 of the bracket 14 and secured therein by means of associated shaft retainers 100, 102. With respect to the installation position 104 of the bracket 14 intended or specified for operation on the three-point linkage 42, the bearing bolt 16 is arranged above the retaining bolt 94 and set back towards the differential housing 50.

[0027] The locking mechanism 90 allows the side stabilizer 12 to be positioned in a way that allows the lower link 58 to be removed. Fig. 2to lock the side stabilizer 12 in the specified rest position 106. In the specified rest position 106, the side stabilizer 12 is inclined upwards with respect to the installation position 104 intended or specified for operation on the three-point linkage 42. Undesired contact between a drawbar that can be attached to the rear 62 of the agricultural tractor 40 and the side stabilizer 12 can then be largely ruled out.

[0028] In Fig. 3 ac is a step-by-step locking sequence depicted during the pivoting of the in Fig. 1 The side stabilizer 12 shown is returned to the specified rest position 106. The sectional view shown reveals the structure of the locking device 10 in detail.

[0029] Accordingly, a recess 110, opening in the pivoting direction 108, is formed on the side stabilizer 12 or the stabilizer housing 82 as part of the locking mechanism 90 for the positive-locking reception of a contact contour 112 of the retaining bolt 94, wherein the retaining bolt 94 can be secured within the recess 110 by means of the catch hook 92. By way of example, the pivoting direction 108 of the side stabilizer 12 is oriented perpendicular to the axis of rotation 18 formed by the bearing bolt 16.

[0030] The recess 110 extends into a locking housing 116 formed integrally on a top surface 114 of the stabilizer housing 82. For example, the retaining bolt 94 has a round cross-section in the area of ​​the locking contact contour 112, the diameter of which is smaller than that of the adjacent bolt sections received by the bores 98 within the side walls 20, 22. The in Fig. 3cThe shown positive fit between the system contour 112 and the recess 110 is achieved taking into account a bearing clearance Δd in the order of 1 to 2 millimeters, provided for reasons of contamination tolerance.

[0031] The catch hook 92 comprises a blind hole 118 provided in the locking housing 116, within which a locking bolt 120 made of steel is mounted to be longitudinally displaceable. is. The blind hole 118 and the locking bolt 120 have interlocking shape features such that rotation of the locking bolt 120 about its own axis within the blind hole 118 is prevented. becomes. The shape features include, for example, a protruding nose on the locking bolt 120, which engages in a groove formed along a wall of the blind hole 118.

[0032] A compression spring 122 is supported on one side by a shoulder 124 formed on the locking bolt 120 and on the other side by an end face 126 of the blind hole 118 and presses it accordingly. Fig. 3 a in a the Out of Taking 110, blocking position 128.

[0033] The locking bolt 120 has a ramp-shaped actuating section 132 at one end 130 facing the recess 110, as well as an inner contour 134 corresponding to the contact contour 112 of the retaining bolt 94. on.In the locked position 128, the inner contour 134 ultimately represents the continuation of the inner contour 136 of the adjacent recess 110, follows it up to a vertex 138, and from there runs essentially straight or tangentially. The straight or tangential section 140 thus formed is oriented perpendicular to the pivot direction 108 of the side stabilizer 12, which leads to a particularly secure fixing of the retaining bolt 94 within the recess 110.

[0034] As can be seen in Fig. 3bAs can be seen, the ramp-shaped actuating section 132 is designed such that the contact contour 112 of the retaining bolt 94 pushes the locking bolt 120 away into a position 142 that releases the recess 110 when the side stabilizer 12 is pivoted towards the predetermined rest position 106. The locking mechanism 90 thus forms a snap lock in which the spring-loaded locking bolt 120 automatically returns to its initial position while locking the side stabilizer 12 as soon as the retaining bolt 94 has assumed its final position within the recess 110.

[0035] At one end 144, opposite the recess 110, the locking bolt 120 protrudes from a through-opening 146 formed in the end face 126, in the form of an actuating element designed as a handle 148. A locking pin 150 running transversely through the handle 148 serves as a counter-stop for the spring-loaded locking bolt 120 within the blind hole 118. The handle 148 allows the locking bolt 120 to be manually deflected against the spring tension into a position 142 that releases the recess 110, so that the locking mechanism 90 can be manually operated for the purpose of unlocking.

[0036] The locking device 10 thus created allows for particularly easy removal of the lower links 58. In a first step, the side stabilizer 12 is detached from the lower link 58 by removing the locking bolt 60. Then, in a second step, the side stabilizer 12 is swung upwards into the predetermined rest position 106 until the retaining bolt 94 engages on the catch hook 92 and is secured there. In a third step, the lower link 58 is removed by releasing the tractor-side joint connection 152 (see [reference]). Fig. 1 ). This process is then repeated for the other lower link 58, with all work steps being easily carried out by a single person.

[0037] It should be noted that the use of the locking device 10 described above is not limited to a specific type of stabilizer; rather, it can also be a purely mechanical side stabilizer, as described in DE 602 00 422 T2.

Claims

1. Locking device, comprising a side stabilizer (12) and a mounting bracket (14) which can be fastened to a three-point power-lift linkage (42), wherein the side stabilizer (12) is attached pivotably to the mounting bracket (14) by means of a bearing pin (16) and can be locked to the mounting bracket (14) by means of a lock mechanism (90) in a predetermined rest position (106), characterized in that the lock mechanism (90) has a spring-preloaded catch hook (92) which is designed for releasably engaging into a mounting pin (94) provided on the mounting bracket (14).

2. Locking device according to Claim 1, characterized in that the mounting bracket (14) has first and second side cheeks (20, 22) which engage around a fastening joint (26) provided on the side stabilizer (12), wherein the bearing pin (16) extends through the two side cheeks (20, 22) and the fastening joint (26) for pivotably attaching the side stabilizer (12).

3. Locking device according to Claim 1 or 2, characterized in that a recess (110) opening in the pivoting direction (108) is formed on the side stabilizer (12) as a component of the lock mechanism (90) for the positively locking reception of a contact contour (112) of the mounting pin (94), wherein the mounting pin (94) can be fixed by means of the catch hook (92) within the recess (110).

4. Locking device according to at least one of the preceding claims, characterized in that there is an actuating element (148) for manually deflecting the catch hook (92) into a position (142) releasing the recess (110).

5. Locking device according to at least one of the preceding claims, characterized in that the catch hook (92) has a ramp-shaped actuating portion (132) such that the mounting pin (94) pushes the catch hook (92) away into a position (142) releasing the recess (110) when the side stabilizer (12) is pivoted in the direction of the predetermined rest position (106).

6. Locking device according to at least one of the preceding claims, characterized in that, in the predetermined rest position (106), the side stabilizer (12) is set obliquely upwards with respect to an installation position (104) provided or specified for operation on the three-point power-lift linkage (42).