Quick-change device

Abstract

The invention relates to a quick-change device (1) in which, in order to secure a locating pin of an attachment and to lock a locking component, respectively, securing pins (3.1) and locking pins (2.3), respectively, are pushed in opposite directions out of the housing (6) of the quick-change device (1), wherein as a first stable state of the quick-change device (1) the locking state is set. In addition to a second stable state, an unlocking state, a third stable state can be set for the quick-change device (1).

Description

[0001] The invention relates to a quick coupler as is known by generic name from DE 10 2020 127 481 B3.

[0002] Work machines, especially those used in construction, agriculture, or forestry, typically feature a tool carrier to which various attachments can be mounted. This allows for a very wide range of applications with just one machine.

[0003] To make tool changes as quick and easy as possible, and to avoid the need for any assembly work on the tool holder, tool holders are often equipped with a quick-change system or are themselves designed as quick-change systems. Quick-change systems have suitable tool receptacles on the tool side, into which the fasteners of the attachment tools can be inserted and secured.

[0004] To attach the implements, the tool holders, or at least parts of them, of the quick coupler are adjustable and movable. The movement of the holders can be achieved in various ways, such as mechanically, hydraulically, electrically, or a combination thereof. Hydraulic drives are particularly advantageous, as most machine tools are already hydraulically operated. These drives allow the operator to change tools without leaving the cab, making tool changes especially quick and convenient.

[0005] However, the use of quick couplers can also involve risks. In the event of incorrect operation or a technical failure of the drives, there is a danger that the attached tool will detach from the quick coupler and fall uncontrollably. To minimize this risk, additional safety devices are generally provided on quick couplers. These are designed to ensure that a correctly mounted tool cannot detach itself from the tool holder without conscious action by the operator. The safety devices can, for example, be movable latches that secure at least one of the attachment's fastening elements in the tool holder.

[0006] Utility model DE 2011 9092U1 discloses a fastening device for attachments on hydraulic excavators. For fastening the tool, one side of the hydraulic quick coupler housing is designed as a rigid pair of retaining jaws. This pair of retaining jaws has hook-shaped receiving openings that can be positively engaged with the outer surface of a first fastening element of the tool (here, a cylindrical bolt). On the other side of the housing, a pair of pivotable retaining jaws is arranged. This pivotable pair of retaining jaws also has hook-shaped receiving openings that can be positively engaged with the outer surface of a second fastening element of the tool (here, a cylindrical bolt).The movement of the pivoting retaining jaw pair around a pivot axis is achieved by a hydraulic cylinder, which allows the distance between the receiving openings of the pivoting and the receiving openings of the fixed retaining jaw pair to be adjusted. To pick up the tool on the quick coupler, the distance between the receiving openings is minimized so that the two retaining jaw pairs can engage between the first and second fasteners. The pivoting retaining jaw pair is then pivoted, thereby increasing the distance between the receiving openings until the receiving openings of all retaining jaws are in positive contact with the fasteners. The force of the hydraulic cylinder holds the tool securely in the hook-shaped receiving openings of the retaining jaws. If the hydraulic pressure is lost, the pivoting retaining jaw pair can detach from the second fastener.To prevent the tool from falling, a locking element is arranged on the rigid pair of retaining jaws. This element consists of a bolt that is tangentially displaceable relative to the first fastener. The bolt is moved into the locked position by spring force and held there. In the locked position, a first fastener, which fits snugly in the hook-shaped receiving openings, is prevented from leaving the receiving openings without first pushing the bolt back against the spring force. The bolt is pushed back into an unlocked position when the pivoting retaining jaws are opened by the hydraulic cylinder. For this purpose, the bolt is connected to a deflection lever, which is actuated by the hydraulic cylinder housing at the end of the opening movement, when the hydraulic cylinder is fully retracted. The locked position is not secured against external forces acting on the bolt.

[0007] US Patent 9,903,091 B2 discloses a hydraulic quick coupler for mounting an attachment tool via two mounting pins. The quick coupler housing has a rigid retaining claw on one side for receiving the first mounting pin and a movable pair of retaining claws on the other side for receiving the second mounting pin. Each retaining claw forms a hook-shaped receiving opening, with the receiving openings of the two retaining claws facing in opposite directions. A locking lever is arranged on the rigid retaining claw and is pivotably mounted in the housing between a locking and a unlocking position. The movable pair of retaining claws is slidably mounted in the quick coupler housing relative to the rigid retaining claw. The movement of the movable pair of retaining claws is effected by a double-acting hydraulic cylinder to which two spring struts are connected in parallel.The hydraulic cylinder is connected on one side to the movable retaining jaw pair and on the other side guided in a slot in the housing by a pin. The guided end has a driver in the form of a protrusion, via which the translational movement of the hydraulic cylinder is converted into a pivoting movement of the locking lever, based on the operating principle of a cam disc.

[0008] To pick up the tool on the quick coupler, the distance between the mounting openings of the holding jaws is minimized by contracting the hydraulic cylinder, allowing it to engage between the first and second mounting bolts. Against the spring forces of the shock absorbers, the hydraulic cylinder is fully retracted, and the drive pulls the pivotally mounted locking lever on the housing into the unlocked position.

[0009] Once the first receiving bolt is correctly positioned in the hook-shaped receiving opening of the rigid holding claw, the hydraulic cylinder expands.

[0010] First, the drive pin on the locking lever is moved, pivoting it into the locking position. In this position, the hook-shaped locking lever engages in the receiving opening of the rigid retaining claw and partially engages the first mounting pin. Simultaneously, the drive pin locks the locking lever in the locking position. As the hydraulic cylinder expands further, the movable pair of retaining claws is moved until it makes contact with the second mounting pin, locking the tool to the quick coupler.

[0011] The locking lever can only be released by contracting the hydraulic cylinder against the spring force of the shock absorbers. This means the locking lever is held in the locked position by the hydraulic pressure in the expanded hydraulic cylinder and additionally by the spring force of the shock absorbers. Any external forces acting on the locking lever are transmitted to the actuator only to a very limited extent, and partial forces in the direction of the hydraulic and spring forces cannot be transmitted, thus preventing the locking lever from being released.

[0012] A quick coupler described in WO 2018 / 056841 A1 differs from the one known from the aforementioned US 9,903,091 B2, particularly in the means for converting the translational movement of the hydraulic cylinder into a pivoting movement of a locking lever. In the unlocked position, one end of the locking lever engages in the opening of a component connected to the movable retaining jaw pair. To lock and secure, the hydraulic cylinder expands, causing the movable retaining jaw pair to move towards the second mounting pin and pivoting the locking lever, carried along in the opening, in front of the first mounting pin. During this pivoting motion, the locking lever slides out of the opening and is pushed under the component, where it is held in place by the spring force of a return spring.

[0013] Here too, in the event of external forces acting upon it, no partial forces acting in the direction of the hydraulic force can be transmitted, thus preventing the safety lever from being unintentionally unlocked.

[0014] Both US 9,903,091 B2 and WO 2018 / 056841 A1 eliminate the risk of unintentional unlocking of the safety lever by largely preventing force from flowing back from the safety lever to the hydraulic cylinder or springs, at least when the safety lever is in the locked position. Forces acting in the direction of the hydraulic cylinder or spring are absorbed by the swivel bearing of the safety lever.

[0015] A hydraulic quick coupler 1 known from patent DE 10 2020 127 481 B3 has, for attaching an implement, a retaining claw 1.2 with an associated locking assembly 3 and a contact surface 1.1 with an associated locking assembly 2, comprising a mounting bolt 0.1 and a locking plate 0.2 as fastening elements. For the sake of clarity, a quick coupler according to the aforementioned DE 10 2020 127 481 B3 is shown in den Fig. 1a und 1b as well as Fig. 2a und 2b schematically shown in a top view and a sectional view.

[0016] This shows Fig. 1a und 1b A quick coupler according to the prior art in a first state (locking state) in which the piston rod 2.1.2 of the hydraulic cylinder 2.1 is in a first end position, in which the locking bolts 2.3 are in a locking position and the safety bolts 3.1 are in a safety position. The locking assembly 2 and the safety assembly 3 are not in contact with each other in the locked state.

[0017] Fig. 2a und 2b shows the quick coupler according to the Fig. 1a und 1b in a second state (unlocked state) in which the piston rod 2.1.2 is in a second end position, in which the locking bolts 2.3 are in an unlocked position and the locking bolts 3.1 are in an unlocked position. In this state, the locking assembly 2 and the locking assembly 3 are in contact with each other.

[0018] The locking assembly 2 comprises a frame-mounted, double-acting hydraulic cylinder 2.1 with a piston rod 2.1.2 which is rigidly connected via a locking bridge 2.2 to two locking bolts 2.3 aligned parallel to the piston rod 2.1.2 and guided through the contact surface 1.1. When the locking chamber or the unlocking chamber of the hydraulic cylinder 2.1 is pressurized, the piston rod 2.1.2 is displaced and the locking assembly 2 assumes either the locked position or the unlocked position.

[0019] The locking assembly 3 comprises two parallel, frame-mounted compression springs 3.2, each associated with a coaxially arranged locking bolt 3.1, thus forming two identical spring-bolt assemblies. The locking bolts 3.1 are attached to a locking bridge 3.3, which connects the spring-bolt assemblies and is translationally displaceable between the locked and unlocked positions in alternating directions. In the locked position, the locking bolts 3.1 project into the receiving opening 1.2.1 of the retaining claw 1.2, thereby reducing the clear width 1.2.1.1 of the receiving opening 1.2.1, so that a receiving bolt 0.1 held in the retaining claw 1.2 can no longer be moved out of the receiving opening 1.2.1.

[0020] To reverse a movement initiated in the locking bridge 2.2 into a movement of the locking bridge 3.3 in the opposite direction, a deflection lever 4 is provided. The locking bridge 3.3, held by spring force, is permanently in contact with a first lever arm 4.1 of the frame-mounted deflection lever 4. A connection of the second lever arm 4.2 is established or broken during the displacement of the piston rod 2.1.2 between the locked and unlocked states. This means that as long as the connection is not established, the movement of the piston rod is not transmitted to the locking assembly 3, and the locking bolts 3.1 are held in the locked position by the spring force of the compression springs 3.2.

[0021] In a quick coupler according to the aforementioned DE 10 2020 127 481 B3, it is ensured that when a work tool is attached to the quick coupler, it is first secured and then locked. It is also ensured that, to decouple the work tool, it is first unlocked before being secured. Securing and locking occur while the locking chamber of the hydraulic cylinder is pressurized, while unlocking and securing occur when the unlocking chamber of the hydraulic cylinder is pressurized.

[0022] This means it is not possible to secure the tool in the unlocked position without necessarily having to lock the tool on the quick coupler afterwards.

[0023] The object of the invention is to find a quick-change device with which a mounted work tool can be unlocked and secured without necessarily being subsequently locked.

[0024] This problem is solved for a quick coupler according to the preamble of claim 1 by providing two stops on the housing, against which one end of each of the two locking bolts rests in the unlocked position, the locking bridge is arranged to be relatively displaceable relative to the abutting ends between two end positions and is resiliently mounted, and the locking bridge is held in the first of the two end positions by hydraulic pressure and in the second of the two end positions by spring force without hydraulic pressure, wherein the locking bridge does not rest against the second lever arm in the second end position and the at least one locking bolt is in the locked position. The relative displaceability of the locking bridge relative to the stops by spring force creates an additional third state for the quick coupler. The adjustability of three static states instead of only two is essential to the invention.

[0025] In a first advantageous embodiment of the quick-change device, the locking bolts each have an elongated hole arranged in the direction of a locking bolt axis, and the locking bridge is guided in the two elongated holes. The adjacent ends are each formed as a collar, and the spring-mounted arrangement of the locking bridge is realized by two coil springs, each arranged between one of the collars and the locking bridge around the locking bolts.

[0026] Advantageously, each locking bolt has a bridge stop against which the bolt bridge rests in its second end position. This means that the adjustment path of the bolt bridge on the locking bolts is not limited in one direction by the end of the elongated hole where guide elements on the bolt bridge would otherwise abut, but rather the guide elements abut the bridge stop just before the end of the elongated hole.

[0027] In a second advantageous embodiment, the locking bolts are formed by an outer bolt part and an inner bolt part guided telescopically therein. The locking bridge is rigidly connected to the outer bolt part, and a spring is provided in each case, coaxially mounted in the outer bolt part and bearing against the inner bolt part, thus realizing the resiliently mounted arrangement of the locking bridge.

[0028] Advantageously, the housing features two blind holes whose bottoms form the stops. A guide sleeve is inserted into each blind hole to guide the inner bolt parts relative to the housing.

[0029] One advantageous aspect of the design is that the locking bridge has a recess into which the free end of the first lever arm engages before or upon reaching the unlocked position of the locking bolt, and is locked in the unlocked position. This ensures that the free end of the first lever arm is held in the recess, even if, for example, a prolonged pressure drop in the hydraulic cylinder releases the connection to the locking bridge. This prevents the receiving opening of the retaining claw from being unintentionally blocked by the locking bolt, especially after extended periods of inactivity, which would otherwise prevent the immediate insertion of a new receiving bolt.

[0030] It has proven advantageous to have a pressure element, movable parallel to the locking bolt, arranged in the retaining claw, which rests against a free end of the second lever arm when the free end of the first lever arm is engaged.

[0031] In a first advantageous embodiment, the pressure element is a coil spring. The spring force of the coil spring assists in the controlled disengagement of the free end of the first lever arm from the recess by shifting the locking pin when the receiving pin is inserted into the retaining claw, thereby rotating the deflection lever out of the recess of the locking bridge. In this way, the deflection lever can be rotated out of the recess with minimal force and thus with minimal wear.

[0032] In a second advantageous embodiment, the pressure element is a pin. By moving the pin, the free end is rotated out of the recess. Advantageously, an indicator pin connected to the locking bridge is provided. It serves as an indicator that the quick-changer is not yet locked.

[0033] It is advantageous if the indicator pin has a recess into which the locking bridge engages.

[0034] To keep the indicator pin in an extended position while the locking bolts are retracted, the length of the recess is preferably dimensioned such that a maximum relative displacement between the indicator pin and the locking bridge is equal to the maximum possible relative displacement between the locking bridge and the locking bolts, determined by the length of the elongated hole.

[0035] The invention is explained in more detail below using an exemplary embodiment and the accompanying drawings. These drawings show: Fig. 1a a quick coupler according to the prior art, in a schematic top view from below, in the locking position of the locking bolts and the securing position of the locking bolts, in conjunction with a locking plate, as a locking component of the attachment tool, Fig. 1b sectional view of the quick coupler, as shown in Fig. 1a , Fig. 2a a quick coupler according to Fig. 1a , in a schematic top view, in the unlocked position of the locking bolts and the unlocked position of the safety bolts, Fig. 2 leg sectional view of the quick coupler, as shown in Fig. 2a Fig. 3a a schematic top view of a first embodiment of a quick coupler according to the invention in the unlocked position of the locking bolts and the unlocked position of the safety bolts, in conjunction with a locking plate as a locking component of the attachment tool, Fig. 3 leg quick coupler according to Fig. 3a in the unlocked position of the locking bolts and the secured position of the locking bolts, Fig. 3, a quick coupler according to Fig. 3a in the locking position of the locking bolts and the secured position of the safety bolts, Fig. 4a a schematic top view of a second embodiment of a quick coupler according to the invention in the unlocked position of the locking bolts and the unlocked position of the safety bolts, Fig. 4 leg quick coupler according to Fig. 4a in the unlocked position of the locking bolts and the secured position of the locking bolts, Fig. 4, a quick coupler according to Fig. 4a in the locking position of the locking bolts and the locking position of the locking bolts, Fig. 5 a quick coupler according to the invention in a sectional view, applicable to the first and the second embodiment, Fig. 6a - 6 a partial view of a quick coupler according to the invention with a first embodiment of a locking assembly, with a recess in the locking bridge into which the deflection lever is engaged in the unlocked position, in various states and Fig. 7a - 7 a partial view of a quick coupler according to the invention with a second advantageous embodiment of a locking assembly with a recess in the locking bridge into which the deflection lever is engaged in the unlocked position, in various states, Fig.Fig. 8a-8 shows a partial view of a quick coupler according to the invention with a third advantageous embodiment of a locking assembly having a recess in the locking bridge into which the deflection lever is engaged in the unlocked position, in various states, and Fig. 9a-9 shows a partial view of a quick coupler according to the invention, with an indicator pin in various states.

[0036] In the Fig. 1a und 1b , as well as 2a und 2b A quick coupler 1 according to the prior art is shown. Similar to a quick coupler 1 according to the invention, a quick coupler according to the invention serves to attach an attachment to a construction machine. The attachment has a mounting bolt 0.1 and a locking component 0.2, here designed as a locking plate, which can be connected to the quick coupler 1.

[0037] As a counterpart to the receiving bolt 0.1 and the locking component 0.2, the quick coupler 1 has a retaining claw 1.2 on a housing 6 for receiving the receiving bolt 0.1 and a contact surface 1.1 for pivoting the locking component 0.2. The retaining claw 1.2 is associated with a locking assembly 3, by means of which a receiving bolt 0.1 received in the retaining claw 1.2 is secured. The contact surface 1.1 is associated with a locking assembly 2, by means of which the pivoted locking component 0.2 is locked to the quick coupler 1.

[0038] The locking assembly 2 comprises a frame-mounted, double-acting hydraulic cylinder 2.1 with a locking chamber 2.1.1, a piston rod 2.1.2 connected via a locking bridge 2.2 to two locking bolts 2.3 aligned parallel to the piston rod 2.1.2 and guided through the contact surface 1.1, and an unlocking chamber 2.1.3. Actuation of the hydraulic cylinder 2.1 pressurizes its locking chamber 2.1.1 to lock the assembly, or alternatively, its unlocking chamber 2.1.3 to unlock it. The hydraulic cylinder 2.1 can also be depressurized by depressurizing the unlocking chamber 2.1.3 and venting the locking chamber 2.1.3.

[0039] When maximum pressure is applied in the locking chamber 2.1.1, the locking bolts 2.3 are in a locking position.

[0040] At maximum pressure in the unlocking chamber 2.1.3, the locking bolts 2.3 are in an unlocked position. The locking component 0.2 is designed here as a locking plate with two through holes into which the locking bolts 2.3 engage. The locking component 0.2 could also be designed, for example, as an additional receiving bolt.

[0041] The locking assembly 3 comprises two parallel, frame-mounted compression springs 3.2, each associated with a coaxially arranged locking bolt 3.1, forming two identical spring-bolt assemblies. The locking bolts 3.1 are attached to a locking bridge 3.3, which connects the spring-bolt assemblies and is translationally displaceable between a locking position and an unlocking position, with alternating directions. In the locking position, the locking bolts 3.1 project into the receiving opening 1.2.1 of the retaining claw 1.2, thereby reducing the clear width 1.2.1.1 of the receiving opening 1.2.1, so that a receiving bolt 0.1 held in the retaining claw 1.2 can no longer be moved out of the receiving opening 1.2.1.

[0042] To reverse a movement initiated in the locking bridge 2.2 into a movement of the locking bridge 3.3 in the opposite direction, a frame-mounted deflection lever 4 is provided. The locking bridge 3.3, held by spring force, is permanently in contact with a first lever arm 4.1 of the frame-mounted deflection lever 4. A connection of the second lever arm 4.2 is established or broken during the displacement of the piston rod 2.1.2 between the locked and unlocked states. That is, as long as the connection is not established, the movement of the piston rod 2.1.2 is not transmitted to the locking assembly 3, and the locking bolts 3.1 are held in the locked position by the spring force of the compression springs 3.2.

[0043] To unlock, an indirect connection is established between the piston rod 2.1.2 and the second lever arm 4.2 by moving the locking bridge 2.2 towards the deflection lever 4 and bringing it into contact with the deflection lever 4. This occurs while pressure is applied to the unlocking chamber 2.1.3. The deflection lever 4 is rotated, and the locking bolts 3.1 are retracted against the spring force of the compression springs 3.2.

[0044] When pressure is applied to the locking chamber 2.1.1, the locking bridge 2.2 is retracted and released from the second lever arm 4.2. The deflection lever 4 rotates back due to the acting spring forces, and the locking bolts 3.1 are extended. For a described quick coupler, according to the prior art, there are only two stable states that the quick coupler can assume: the locked state, in which the locking bolts 2.3 and the locking bolts 3.1 are each extended and in a locking position, and the unlocked state, in which the locking bolts 2.3 and the locking bolts 3.1 are each retracted and in a locking position.

[0045] In contrast to a quick coupler 1 according to the prior art, a quick coupler 1 according to the invention can assume three stable states, wherein in the additional third stable state the locking bolts 2.3 are still in the unlocked state, but the locking bolts 3.1 have reached the locked position. In order for this third stable state to be adjustable for the quick coupler 1, it differs significantly, in particular, in the design of the locking bolts 2.3 and the connection of the locking bolts 2.3 with the locking bridge 2.2.

[0046] The differences essential to the invention are explained below based on the Fig. 3a - 3c and Fig. 4a - 4c explained. For the sake of simplicity, the same reference symbols are used for means designated identically to the prior art, even if these differ from those of the prior art. In Fig. 5 A sectional view is shown which applies to both embodiments described below and from which the features identical to those of the prior art are evident. Fig. 3a - 3c and Fig. 4a - 4c are not apparent.

[0047] In the Fig. 6a - 6d , 7a - 7d and 8a - 8d Two different versions of the locking assembly are shown in different states of the quick coupler, as they can each be advantageously combined with the aforementioned embodiments.

[0048] In the Fig. 9a - 8c is the one in the Fig. 3a -3c and Fig. 4a -4c The indicator pin is shown schematically, with its position relative to the locking bolts in various states of the quick coupler. If the indicator pin is extended, the quick coupler is not yet locked.

[0049] According to a first embodiment, shown in den Fig. 3a - 3c , The locking bolts 2.3 each have an elongated hole 8 arranged in the direction of a locking bolt axis 2.3.2. The locking bridge 2.2 is slidable on the two locking bolts 2.3.2 in the direction of the locking bolt axes 2.3, the maximum displacement being limited by the length of the elongated holes 8 by guide elements 5 on the locking bridge 2.2 that engage in the elongated holes 8. The housing 6 has two stops 7 against which, at maximum pressure in the unlocking chamber 2.1.3, one end 2.3.1 of each locking bolt 2.3 rests. A collar 9 is formed at each of these ends 2.3.1, and a coil spring 10 is arranged on each locking bolt 2.3 between the collars 9 and the locking bridge 2.2.

[0050] If the unlocking chamber 2.1.3, starting from a state as in Fig. 3c As shown, when pressure is applied, the locking bridge 2.2 is first moved along the elongated holes 8 towards the stops 7 from a second end position on the locking bolt 2.3 to a first end position on the locking bolt 2.3, whereby the coil springs 10 are tensioned, as shown in Fig. 3b As shown, as the locking bridge 2.2 slides forward, it engages the locking bolts 2.3 until they come to rest against the stops 7, as shown in Fig. 3a The figure shows the locking bolts 2.3 in an unlocked position. The quick coupler 1 is now in an unlocked state, similar to a prior art quick coupler, in which the locking bolts 2.3 and the safety bolts 3.1 are each retracted, i.e., in an unlocked position and a disengaged position, respectively.

[0051] Subsequently, by depressurizing the hydraulic cylinder 2.1, the spring force of the coil springs 10 pushes the locking bridge 2.2 away from the stops 7 in the elongated holes 8 and back into the second end position against the locking bolt 2.3. Advantageously, the locking bolts 2.3 each have a bridge stop 11 against which the locking bridge 2.2 comes to rest in the second end position shortly before the maximum displacement, limited by the length of the elongated holes 8, is reached. This prevents the locking bridge 2.2 from impacting the ends of the elongated holes 8 and thus avoids any potential damage to the locking bolts 2.3. The quick coupler 1 is now in a static state, which a quick coupler 1 cannot assume according to the prior art. The locking bolts 2.3 are still retracted and in the same unlocked position as before. The locking bolts 3.1, however, are extended and are accordingly in the locking position, since the connection of the locking bridge 2.2 with the deflection lever 4 has been released and the deflection lever 4 could rotate, thereby moving the locking bolts 3.1 by spring force.

[0052] In Fig. 3a The quick coupler 1 according to the first embodiment is shown in the unlocked state, in which, with pressure applied in the unlocking chamber 2.1.3, the locking bolts 2.3 are in an unlocked position and the locking bolts 3.1 are in an unlocked position. The deflection lever 4 and the locking bridge 2.2 are in a relative position to each other as shown in Fig. 2b shown.

[0053] In Fig. 3b The quick coupler 1 according to the first embodiment is shown in the locked state, in which, with the hydraulic cylinder 2.1 depressurized, the locking bolts 2.3 are still in the same unlocked position and the locking bolts 3.1 are in a locked position. The deflection lever 4 and the locking bridge 2.2 are in a relative position to each other, with the deflection lever 4 in a position as shown in [reference to diagram]. Fig. 1b as shown, however the distance between the deflection lever 4 and the locking bridge 2.2 is very small, significantly less than shown here.

[0054] In Fig. 3c The quick coupler 1 according to the first embodiment is shown in the locked state, in which, with pressure applied in the locking chamber 2.1.1, the locking bolts 2.3 are in a locked position and the safety bolts 3.1 are in the secured position. The deflection lever 4 and the locking bridge 2.2 are in a relative position to each other as shown in Fig. 1b shown.

[0055] According to a second embodiment, shown in den Fig. 4a - 4c ,The locking bolts 2.3 are formed by an outer bolt part 2.3.3 and an inner bolt part 2.3.4 guided telescopically within it, and the locking bridge 2.2 is fixedly connected to the outer bolt part 2.3.3. A spring 2.3.5 is coaxially mounted in the outer bolt part 2.3.3 and rests against an inner end of the inner bolt part 2.3.4. The housing also has 6 stops 7 against which the free end of the inner bolt part 2.3.4 rests in the unlocked position.

[0056] When the unlocking chamber 2.1.3 is pressurized, the locking bridge 2.2 is moved maximally towards the stops 7 by placing the inner bolt parts 2.3.4 against the stops 7 and then pushing them maximally into the outer bolt parts 2.3.4 against the spring force of the springs 2.3.5, thereby tensioning the springs 2.3.5.

[0057] Subsequently, by depressurizing the hydraulic cylinder 2.1, the inner bolt parts 2.3.4 are pushed out of the outer bolt parts 2.3.3 as the springs 2.3.5 release. This moves the outer bolt parts 2.3.3, with the locking bridge 2.2 attached to them, away from the components 7 until the springs 2.3.5 are fully released or their further release within the outer bolt parts 2.3.3 is mechanically limited. It is important that the locking bolts 2.3 are dimensioned such that the outer bolt parts 2.3.3 do not protrude from the quick coupler 1 in either of the described states and are therefore in an unlocked position.

[0058] Advantageously, the housing 6 has two blind holes 12, each with a base that forms one of the stops 7 and each with an inserted guide sleeve 13 in which one of the inner bolt parts 2, 3, 4 is guided.

[0059] In Fig. 4a The quick coupler 1 according to the second embodiment is shown in the unlocked state, in which, with pressure applied in the unlocking chamber 2.1.3, the locking bolts 2.3 are in an unlocked position and the locking bolts 3.1 are in an unlocked position. The deflection lever 4 and the locking bridge 2.2 are in a relative position to each other as shown in Fig. 2b shown.

[0060] In Fig. 4b The quick coupler 1 according to the second embodiment is shown in the locked state, in which the locking bolts 2.3 are still in the same unlocked position and the locking bolts 3.1 are in a locked position. The deflection lever 4 and the locking bridge 2.2 are in a relative position to each other, with the deflection lever 4 in a position as shown in Figure 1. Fig. 1b as shown, however the distance between the deflection lever 4 and the locking bridge 2.2 is very small, significantly less than shown here.

[0061] In Fig. 4c The quick coupler 1 according to the second embodiment is shown in the locked state, in which, with pressure applied in the locking chamber 2.1.1, the locking bolts 2.3 are in a locked position and the safety bolts 3.1 are in the secured position. The deflection lever 4 and the locking bridge 2.2 are in a relative position to each other, as shown in Fig. 1b shown.

[0062] In further embodiments, the locking assembly 3 can be designed differently. It can also consist of only a spring-bolt assembly with a frame-mounted compression spring 3.2 and a locking bolt 3.1 arranged coaxially with it, the locking bolt having a locking bolt axis 3.1.1, which is translationally displaceable between a locking position and an unlocking position in the direction of the locking bolt axis 3.1.1. It is also not essential to the invention whether the locking bolt is connected indirectly, e.g., via a locking bridge 3.3, or directly to the deflection lever 4.

[0063] Fig. 6a - 6d Figure 1 shows a partial view of a quick coupler 1 according to the invention with a first embodiment of a locking assembly 3, with a recess 3.3.1 in the locking bridge 3.3, into which the deflection lever 4 is engaged in the unlocked position, in various states.

[0064] In Fig. 6a The figure shows an unlocked state. A free end of the first lever arm 4.1 is engaged in the recess 3.3.1 of the locking bridge 3.3 and the locking bolt 3.1 protrudes slightly into the receiving opening 1.2.1. A pressure element 14, here a coil spring, arranged in the retaining claw 1.2 parallel to the locking bolt 3.1, rests against the second lever arm 4.2.

[0065] At the in Fig. 6b In the state shown, the receiving bolt 0.1 has already been partially engaged by the retaining claw 1.2, whereby the locking bolt 3.1 has been completely pushed out of the receiving opening 1.2.1 by the receiving bolt 0.1 and the free end of the first lever arm 4.1 is released, supported by the effect of the spring force of the coil spring.

[0066] The locking bridge 3.3 now moves unhindered by the deflection lever 4 immediately towards the receiving opening 1.2.1 as soon as the receiving bolt 0.1 is fully inserted into the retaining claw 1.2 and no longer blocks the guide path for the locking bolt 3.1, as shown in the Fig. 6c und 6d is shown.

[0067] In the Fig. 7a - 7d Figure 1 shows a partial view of a quick coupler according to the invention with a second advantageous embodiment of a locking assembly 3 having a recess 3.3.1 in the locking bridge 3.3, into which the deflection lever 4 is engaged in the unlocked position, in various states.

[0068] In contrast to the previously described embodiment, here the pressure element 14 is a pin that projects into the receiving opening 1.2.1 and is pushed out of the receiving opening 1.2.1 when the receiving bolt 0.1 is inserted. This rotates the deflecting lever 4 and rotates the free end of the first lever arm 4.1, which engages in the locking bridge 3.3, out of the recess 3.3.1. Subsequently, the locking bridge 3.3 can be pushed unhindered towards the release opening 1.2.1 by the spring force of the compression spring 3.2, thereby moving the locking bolt 3.1 into the receiving opening 1.2.

[0069] In the Fig. 8a - 8d Figure 1 shows a partial view of a quick coupler according to the invention with a third advantageous embodiment of a locking assembly 3 having a recess 3.3.1 in the locking bridge 3.3, into which the deflection lever 4 is engaged in the unlocked position, in various states.

[0070] In contrast to the previously explained design of the safety assembly 3 according to the Fig. 6a -6d The pressure element 14 here is a pen-spring combination.

[0071] In the Fig. 9a - 9c The indicator pin 15 is shown in its interaction with the locking bridge 2.2 in various states of the quick coupler 1. The indicator pin 15 is connected to the locking bridge 2.2 and is displaceable in the housing 6 (not shown here) in the same direction as the locking bridge 2.2, whereby a displacement introduced into the locking bridge 2.2 is transmitted only over a portion of the locking bridge 2.2's range of motion with a 1:1 transmission ratio.

[0072] At the in Fig. 9a In the depicted state of the quick coupler 1, the indicator pin 15 protrudes from the quick coupler 1 in an extended position, in which, according to the Fig. 3a and 4a, the locking bolts 2.3 are in the unlocked position and the safety bolt 3.1 is in the unlocked position.

[0073] If the locking bridge 2.2 is now moved from this first end position, with the quick coupler in the Fig. 3b and 4b When the depicted state is transitioned to, the indicator pin 15 is not moved along and remains in the extended position, as shown. Fig. 9b shown.

[0074] Upon further displacement of the bar bridge 2.2 into the second end position, which is in the Fig. 3c and 4c As shown, the indicator pin 15 is carried along by the locking bridge 2.2 and moved into a retracted position, as shown in Fig. 9c shown.

[0075] The displacement of the indicator pin 15 is limited by a stop pin 16. To ensure that the indicator pin 15 is only moved through part of the range of motion of the locking bar 2.2, the indicator pin has a recess extending in the direction of its pin axis into which the locking bar 2.2 engages. Thus, the indicator pin can only be moved by the locking bar when it abuts a limit of the recess.

[0076] Alternatively, the indicator pin 15 has a further elongated hole extending in the direction of its pin axis, into which a drive pin located on the locking bridge 2.2 engages.

[0077] The recess 17 and the further elongated hole have a length that is designed to allow a maximum relative displacement between the indicator pin 15 and the locking bridge 2.2 that is the same length as the maximum possible relative displacement between the locking bridge 2.2 and the locking bolts 2.3, determined by the length of the elongated hole 5. Reference symbol list

[0078] 0.1 Mounting bolt (of an attachment) 0.2 Locking component (of an attachment) 1 Quick coupler 1.1 Mounting surface 1.2 Retaining claw 1.2.1 Mounting opening 1.2.1.1 Clear width 2 Locking assembly 2.1 Hydraulic cylinder 2.1.1 Locking chamber 2.1.2 Piston rod 2.1.3 Unlocking chamber 2.2 Locking bridge 2.3 Locking bolt 2.3.1 End of the locking bolt 2.3.2 Locking bolt axis 2.3.3 Outer bolt part 2.3.4 Inner bolt part 2.3.5 Spring 3 Safety assembly 3.1 Safety bolt 3.1.1 Safety bolt axis 3.2 Compression spring 3.3 Safety bridge 3.3.1 Recess 4 Deflection lever 4.1 First lever arm 4.2 Second lever arm 5 Guide element 6 Housing 7 Stop 8 Slotted hole 9 Collar 10 Coil spring 11 Bridge stop 12 Blind hole 13 Guide sleeve 14 Pressure element 15 Indicator pin 16 Stop pin 17 Recess

Claims

1. Quick-change device (1) for mounting a work tool on a construction machine, wherein the work tool comprises a receiving bolt (0.1) and a locking component (0.2), with a housing (6) on which a holding claw (1.2) is provided to receive the receiving bolt (0.1) to which holding claw (1.2) a securing assembly (3) is assigned, a contact surface (1.1) is provided for contacting the locking component (0.2) to which contact surface (1.1) a locking assembly (2) is assigned, and a rotably mounted two-armed deflection lever (4) is provided, wherein the locking assembly (2) comprises a double-acting hydraulic cylinder (2.1) with a piston rod (2.1.2), wherein said hydraulic cylinder (2.1) is fixedly mounted to a frame, a bar bridge (2.2) and two locking bolts (2.3), wherein the bar bridge (2.2) is firmly connected to the piston rod (2.1.2) and the locking bolts (2.3) are guided parallelly to the piston rod (2.1.2) and through the contact surface (1.1) and are connected to the bar bridge (2.2), so that the locking bolts (2.3) can be moved alternately into a locking position or into a release position by applying hydraulic pressure to the hydraulic cylinder (2.1), wherein the securing assembly (3) comprises at least one spring bolt assembly with a compression spring (3.2) which is fixedly mounted to the frame, and a securing bolt (3.1) arranged coaxially thereto and having a securing bolt axis (3.1.1) and being translationally displaceable between a securing position and an unlocking position in the direction of the securing bolt axis (3.1.1), and the securing bolt (3) partially protrudes into a receiving opening (1.2.1) of the holding claw (1.2) in the securing position, thereby reducing a clear width (1.2.1.1) of the receiving opening (1.2.1) such that the receiving bolt (0.1) received in the holding claw (1.2) can no longer be moved out of the receiving opening (1.2.1), and wherein the deflection lever (4) is permanently connected with the securing assembly (3) via a first lever arm (4.1) and with the bar bridge (2.2) in the unlocking position via a second lever arm (4.2), characterized in that two stops (7) are provided at the housing (6) which stops (7) are contacted by one end (2.3.1) respectively of one of the two locking bolts (2.3) in the unlocking position, the bar bridge (2.2) is arranged spring-mounted and displaceable relative to the contacting ends (2.3.1) along the locking bolt (2.3) between two final positions, and the bar bridge (2.2) is held in the first of the two final positions by hydraulic pressure and in the second of the two final positions without hydraulic pressure by spring force, wherein the bar bridge (2.2) does not contact the second lever arm (4.2) in the second postion and the at least one securing bolt (3.1) is in the securing position.

2. Quick-change device (1) according to claim 1, characterized in that the locking bolts (2.3) each comprise an elongated hole (8) arranged in the direction of a locking bolt axis (2.3.2), the bar bridge (2.2) is guided within both elongated holes (8), the contacting ends (2.3.1) are each formed as a collar (9) and the spring-mounted arrangement of the bar bridge (2.2) is realized by two coil springs (10) that are each arranged around the locking bolts (2.3) between one of the collars (9) and the bar bridge (2.2).

3. Quick-change device (1) according to claim 2, characterized in that the locking bolts (2.3) each comprise a bridge stop (11) which the bar bridge (2.2) contacts in the second final position.

4. Quick-change device (1) according to claim 1, characterized in that the locking bolts (2.3) are formed by an outer bolt part (2.3.3) and an inner bolt part (2.3.4) telescopically guided therein, the bar bridge (2.2) is firmly connected to the outer bolt part (2.3.3), and a spring (2.3.5) which is coaxially mounted in each outer bolt part (2.3.3) and contacts the inner bolt part (2.3.4.) is provided, which spring (2.3.5) realizes the spring-mounted arrangement of the bar bridge (2.2).

5. Quick-change device (1) according to claim 1, characterized in that two bag holes (12) are provided in the housing (6), each having a bottom that forms one of the stops (7), and in each of the bag holes (12) a guide sleeve (13) for guiding the inner bolt part (2.3.4) is inserted.

6. Quick-change device (1) according to claim 1, characterized in that the securing bridge (3.3) comprises a recess (3.3.1) in which a free end of the first lever arm (4.1) is latched in the release position of the securing bolt (3.1).

7. Quick-change device (1) according to claim 6, characterized in that in the holding claw (1.2) a pressing element (14) is arranged which can be moved parallel to the securing bolt (3.1) and which contacts a free end of the second lever arm (4.2) when a free end of the first lever arm (4.1) is latched.

8. Quick-change device (1) according to claim 6 or 7, characterized in that the pressing element (14) is a coil spring.

9. Quick-change device (1) according to one of the claims 6 to 8, characterized in that the pressing element (14) is a pin.

10. Quick-change device (1) according to claim 1, characterized in that an indicator pin (15) is provided, which is connected to the bar bridge (2.2).

11. Quick-change devices (1) according to claim 10, characterized in that a recess (17) is provided in the indicator pin (15), into which the bar bridge (2.2) engages.

12. Quick-change device (1) according to claim 11, characterized in that a length of the recess (17) is dimensioned in such a way that an equally long maximum relative displacement between the indicator pin (15) and bar bridge (2.2) is possible, corresponding to a maximum possible relative shift between the bar bridge (2.2) and the locking bolt (2.3), determined by the length of the elongated hole (5).

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