Chain magazine for tools of a machine tool

Abstract

A chain magazine for a tool of a machine tool, having a rotary magazine chain which has links articulated to one another, at least one link being designed as a tool gripper which has two jaws and a control bolt, at least one jaw being pivotally supported for gripping the tool, the control bolt being axially movably supported between an open position and a closed position and controlling the pivoting movement of at least one pivotable jaw so as to open at least one pivotable jaw in the open position for inserting and removing the tool and to close at least one pivotable jaw in the closed position for gripping the tool, according to the invention, the chain magazine having locking means for controlling the chain curvature of the control bolt which locks the control bolt in the closed position when the closed tool gripper and its adjacent link are inclined relative to one another and does not lock the control bolt in the closed position when the closed tool gripper and its adjacent link are not inclined relative to one another.

Description

Technical Field

[0001] The invention relates to a chain magazine for tools of a machine tool, having a rotary magazine chain which has links articulated to one another, at least one of the links being designed as a tool gripper which has two jaws and a control bolt, at least one of the jaws being pivotally supported for gripping the tool, the control bolt being axially movably supported and controlling the pivoting movement of the at least one pivotable jaw between an open position and a closed position in order to open the at least one pivotable jaw for inserting and removing the tool in the open position and to close the at least one pivotable jaw for gripping the tool in the closed position. Background Art

[0002] Such a chain magazine has already been disclosed, for example, by DE 40 31 996 A1.

[0003] The tool-chain magazine serves as a tool magazine of a machining center and enables automatic tool change. The links of the magazine chain are designed as grippers for gripping the tool, and the tool is exchanged from the tool-chain magazine to the machining spindle of the machining center by means of the tool gripper and vice versa.

[0004] In a vertically oriented tool-chain magazine, the tool received in the tool gripper not only bears the weight force but also the centrifugal force in the curved chain section, and in today's kinematics, the centrifugal force can reach 220% of the weight force. Therefore, in the curved chain section, the force acting on the received tool may cause the control bolt to move, resulting in the jaws opening and the tool being thrown out. Summary of the Invention

[0005] In contrast, the object of the invention is to reliably prevent the jaws from opening in the curved chain section in a chain magazine of the above type.

[0006] According to the invention, the object is solved in a chain magazine of the above type by a locking device controlled by the chain curvature of the control bolt, which locks the control bolt in the closed position when the closed tool gripper and its adjacent link are inclined relative to one another and does not lock the control bolt in the closed position when the closed tool gripper and its adjacent link are not inclined relative to one another.

[0007] According to the invention, the control bolt is locked in its closed position when the tool gripper is on a curved chain section and is not locked in its closed position when the tool gripper is on a non-curved chain section. Therefore, the control bolt is only released to move in the opening direction on a non-curved chain section where no centrifugal force acts.

[0008] Particularly preferably, the locking device of the tool gripper includes at least one movably supported locking element controlled by two adjacent links thereof. The locking element is in a locking position for locking the control bolt in the closed position when the closed tool gripper and its adjacent link are inclined relative to each other, and is in a release position for not locking the control bolt in the closed position when the closed tool gripper and its adjacent link are not inclined relative to each other. Especially in the case of heavy tools, the locking device of the tool gripper advantageously has two locking elements respectively controlled by one of two adjacent links. These locking elements are respectively in the locking position when the closed tool gripper and its adjacent link are inclined relative to each other, and are respectively in the release position when the closed tool gripper and its adjacent link are not inclined relative to each other.

[0009] Preferably, the at least one locking element is preloaded to the release position by a restoring force, such as the restoring force of a return spring, so that it can move from the release position to the locking position against the action of the restoring force.

[0010] The locking element can be guided between the release position and the locking position, for example pivotally or preferably linearly movably. In the latter case, the locking element can advantageously be designed as a locking bolt or a locking pin.

[0011] In a preferred embodiment, the adjacent link pivotally supported on the tool gripper about the hinge axis has a control cam (or control curve) extending about the hinge axis. The control cam controls the movement of the locking element such that the locking element is in the locking position when the closed tool gripper and its adjacent link are inclined relative to each other, and is in the release position when the closed tool gripper and its adjacent link are not inclined relative to each other.

[0012] For example, the control cam can be a chute for guiding the locking element or preferably formed by the radially outwardly directed outer edge of the adjacent link, wherein the locking element is kept in contact with the outer edge by a spring at one end. In this case, the control cam particularly preferably has a circular cam section and a recess provided in the circular cam section. The circular cam section is centered on the hinge axis and defines the locking position of the locking element, and the recess defines the release position of the locking element.

[0013] Preferably, the control bolt has an undercut portion pointing in the opening direction of the control bolt, and the locking element abuts against the undercut portion in the locking position, thereby locking or locking the control bolt in the closed position.

[0014] Alternatively, the locking device of the tool gripper may also not be controlled by adjacent links, but instead be designed as a centrifugal locking device integrated in the tool gripper, which has a locking element that is in the released position when the closed tool gripper moves along a non-curved chain section and moves radially outward from the released position against the action of the restoring force to the locked position due to centrifugal force when the closed tool gripper moves along a curved chain section.

[0015] The tool gripper preferably has two pivotable jaws, which are pivotally supported about parallel pivot axes, wherein the control bolt is arranged in the middle between the two jaws and is arranged with its bolt axis perpendicular to the plane spanned by the two parallel pivot axes. Alternatively, instead of two pivot axes, there may be a common pivot axis for the two jaws, wherein the control bolt may be arranged centrally between the two jaws and extend with its bolt axis perpendicular to the common pivot axis.

[0016] Especially in the case of light tools, one or two adjacent links may be designed as tool grippers. On the contrary, especially in the case of heavy tools, neither of the two adjacent links should be designed as a tool gripper so that the force received by this chain section remains low.

[0017] Other advantages of the present invention can be derived from the description and the drawings. Similarly, according to the present invention, the above-mentioned features and the features yet to be listed can also be used alone or in combination with each other in any way separately or in plurality. Description of the Drawings

[0018] The embodiments shown and described should not be understood as exhaustive, but rather have features exemplary for the illustration of the present invention. The present invention is shown schematically in the drawings so that the basic features of the present invention can be well recognized. The drawings are not necessarily to be understood as being drawn to scale.

[0019] In the drawings:

[0020] Figure 1 Schematically shows a chain magazine in the form of a rotary bin, all of whose links are designed as tool grippers;

[0021] Figure 2a , 2b shows a conventional tool gripper in the open gripper position ( Figure 2a ) and the closed gripper position ( Figure 2b );

[0022] Figure 3 Shows a plurality of adjacent tool grippers of the chain magazine according to the present invention, wherein the tool grippers are locked in a chain curvature control manner;

[0023] Figure 4a ,4b shows the locking of the tool gripper in the locking position ( Figure 4a ) and the release position ( Figure 4b ) of the locking element, and the locking in the manner of chain curvature control as shown in Figure 3 ; and

[0024] Figure 5 shows the improved locking of the tool gripper in the manner of chain curvature control by two locking elements. Detailed Description

[0025] Figure 1 The chain magazine generally designated by 1 in

[0026] Figure 2a 、 2b is used to receive the horizontal tool 2 (Figure 2) of a machine tool and has a rotary magazine chain 3, which has links 4 articulated to each other, and all these links are designed as tool grippers 5. Here, the chain plane defined by the magazine chain 3 extends entirely in the vertical plane, but can also extend only sectionally in the vertical plane. The magazine chain 3 has not only curved chain sections 3a, but also non-curved, i.e., linear, chain sections 3b. The changing position P for changing the tool 2 into and out of the machine tool is located on the non-curved, here horizontal, chain section 3b. Figure 2a The conventional tool gripper 5 shown in Figure 2b has a base body 6, two jaws 9 pivotally supported on the base body 6 about pivot axes 8 extending parallel to the hinge axis 7 for gripping the tool 2, and a control bolt 10 centrally arranged between the two jaws 9 and arranged with its bolt axis at right angles to the plane spanned by the two pivot axes 8. The link 4 is pivotally articulated to both sides of the base body by means of a hinge bolt about the hinge axis 7. The control bolt 10 can move axially between Figure 2a the lower open position shown in Figure 2b and

[0027] the upper closed position shown in Figure 2a 、 2b and has a control profile 11 for controlling the pivoting movement of the two jaws 9, which in the open position of the control bolt 10 opens or spreads the jaws 9 for inserting and removing the tool 2 and in the closed position closes the jaws 9 for gripping the tool 2. Figure 2a 、 2b As shown, the two jaws 9 can each be designed as a double-arm lever, for example, where one lever arm 9a (the lower lever arm in Figure 2a 、 2b ) forms the gripping arm, and the other lever arm 9b ( Figure 2a 、 2b the upper lever arm in Figure 2a 、 2b ) interacts with the axial control profile 11. The control bolt 10 is preloaded into the closed position by a spring 12 (one end of which is supported on the base body 6 and the other end on the control bolt 10).

[0028] When the control bolt 10 is moved downward from the closed position ( Figure 2b ) against the action of the spring 12 by means of a drive (not shown here, for example a hydraulic drive) to the open position ( Figure 2a ), it (here by means of a shoulder 13 present on the jaw 9) transfers the jaw 9 from the closed position to the open gripper position, in which the upper lever arm 9b pivots inwards, precisely until it abuts against the axial control profile 11. When the control bolt 10 is moved upward from the open position ( Figure 2a ) to the closed position ( Figure 2a ) by means of the drive device, the upper lever arm 9b is deflected outwards by the axial control profile 11, so that the jaw 9 pivots into the closed gripper position.

[0029] Figure 3 Three adjacent tool grippers 5 of the chain magazine 1 according to the invention are shown. The control bolts 10 of the tool grippers 5 each have locking means 14 controlled by the chain curvature, which lock the control bolt 10 in the closed position if the closed tool gripper 5 and its adjacent tool gripper 5 are inclined relative to each other, and which do not lock the control bolt 10 in the closed position if the closed tool gripper 5 and its adjacent tool gripper 5 are not inclined relative to each other. Thus, the control bolts 10 of the tool grippers 5 are locked or not locked in the closed position by means of the locking means 14 depending on the chain curvature of the respective chain sections 3a, 3b.

[0030] As Figure 4a 、 4b shown in more detail, the locking means 14 of the right tool gripper 5 has a movably supported locking element 15 controlled by the adjacent left tool gripper 5, which is in the locking position ( Figure 4a ) locking the control bolt 10 in the closed position when the closed right tool gripper 5 and the left tool gripper 5 are inclined relative to each other, and which is in the release position ( Figure 4b ) not locking the control bolt 10 in the closed position when the closed right tool gripper 5 and the left tool gripper 5 are not inclined relative to each other. The locking element 15 (here in the form of a locking pin) is guided linearly movable between the release position and the locking position (here at right angles to the bolt axis of the control bolt 10), and can be moved from the release position to the locking position against the action of a return spring 16 supported on the base body 6. In this locking position, the locking element 15 abuts against an undercut 18 of the control bolt 10 pointing in the opening direction 17 of the control bolt 10, thus locking the control bolt in its closed position.

[0031] Figure 4a 、 4bThe tool gripper 5 on the left in [the figure] has a control cam 19 extending around the hinge axis 7, which controls the movement of the locking element 15 such that when the closed right tool gripper 5 and the left tool gripper 5 are inclined relative to each other, the locking element 15 is in the locked position, and when the closed right tool gripper 5 and the left tool gripper 5 are not inclined relative to each other, the locking element 15 is in the released position. The control cam 19 is formed by the radially outwardly directed outer edge of the left tool gripper 5, and the locking element 15 is kept in abutment with this outer edge by a return spring 16. The outer edge has a circular cam section 19a and a recess 19b provided in the circular cam section 19a. The circular cam section is centered on the hinge axis 7 and defines the locked position of the locking element 15, and the recess defines the released position of the locking element 15.

[0032] In Figure 4a [the figure], the two tool grippers 5 are inclined relative to each other. Thus, the locking element 15 is held in the locked position by the circular cam section 19a. As Figure 4b shown, once the two tool grippers 5 are no longer inclined relative to each other, the locking element 15 is pushed by the return spring 16 into the recess 19b, that is, into the unlocked released position.

[0033] In Figure 5 [the figure], the locking device 14 for controlling the chain curvature of the tool gripper 5 has two locking elements 15, which are respectively controlled by one of two adjacent chain links 4. When one or two adjacent chain links 4 are inclined relative to the closed tool gripper 5, one or two locking elements 15 are in the locked position, and the control bolt 10 is locked in the closed position. Only when neither of the two adjacent chain links 4 is inclined relative to the closed tool gripper 5 are the two locking elements 15 in the released position and the control bolt 10 not locked in the closed position. In Figure 5 [the figure], the left adjacent chain link 4 is inclined relative to the closed tool gripper 5, so the left locking element 15 is in the locked position. The right adjacent chain link 4 is not inclined relative to the closed tool gripper 5, so the right locking element 15 is in the released position. Thus, the control bolt 10 is locked in its closed position by the left locking element 15.

[0034] In an embodiment (not shown) of the present invention, the locking device of the tool gripper 5 can alternatively be designed as a centrifugal locking device integrated in the tool gripper 5 and having a locking element (such as a ball) that is in the released position when the closed tool gripper moves along a non-curved chain section 3b, and that moves radially outward from the released position against the action of the return spring to the locked position due to centrifugal force when the closed tool gripper 5 moves along a curved chain section 3a.

Claims

1. A chain magazine (1) for a tool (2) of a machine tool, having a rotary magazine chain (3) with links (4, 5) articulated to one another, at least one of the links being designed as a tool gripper (5), wherein the tool gripper (5) has two jaws (9) and a control bolt (10), at least one of the jaws being pivotally supported to grip the tool (2), the control bolt being axially movably supported between an open position and a closed position and controlling the pivoting movement of at least one pivotable jaw (9) so as to open the at least one pivotable jaw (9) in the open position for inserting and removing the tool (2) and to close the at least one pivotable jaw (9) in the closed position for gripping the tool (2). It is characterized in that A locking device (14) for controlling the chain curvature of the control bolt (10) is provided, which locks the control bolt (10) in the closed position when the closed tool gripper (5) and its adjacent link (4) are inclined relative to each other and does not lock the control bolt (10) in the closed position when the closed tool gripper (5) and its adjacent link (4) are not inclined relative to each other.

2. The chain magazine according to claim 1, characterized in that The locking device (14) of the tool gripper (5) has at least one movably supported locking element (15) controlled by one of its two adjacent links (4), which is in the locking position for locking the control bolt (10) in the closed position when the closed tool gripper (5) and its adjacent link (4) are inclined relative to each other and is in the release position for not locking the control bolt (10) in the closed position when the closed tool gripper (5) and its adjacent link (4) are not inclined relative to each other.

3. The chain magazine according to claim 1 or 2, characterized in that The locking device (14) of the tool gripper (5) has two locking elements (15) respectively controlled by one of the two adjacent links (4), which are respectively in the locking position when the closed tool gripper (5) and its adjacent link (4) are inclined relative to each other and are respectively in the release position when the closed tool gripper (5) and its adjacent link (4) are not inclined relative to each other.

4. The chain magazine according to claim 2, characterized in that At least one locking element (15) is movable from the release position to the locking position against the action of a restoring force.

5. The chain magazine according to claim 2, characterized in that The locking element (15) can be guided to move linearly between the release position and the locking position.

6. The chain magazine according to claim 2, characterized in that The adjacent link (4) is pivotally supported on the tool gripper (5) about a hinge axis (7) and has a control cam (19) extending around the hinge axis (7), which controls the movement of the locking element (15) such that the locking element (15) is in the locking position when the closed tool gripper (5) and its adjacent link (4) are inclined relative to each other and is in the release position when the closed tool gripper (5) and its adjacent link (4) are not inclined relative to each other.

7. The chain magazine according to claim 6, characterized in that The control cam (19) is formed by the radially outwardly directed outer edge of the adjacent link (4), and the locking element (15) is kept in contact with the outer edge by a spring (16).

8. The chain magazine according to claim 7, characterized in that The outer edge has a circular cam section (19a) and a recess (19b) provided in the circular cam section (19a). The circular cam section is centered on the hinge axis (7) and defines the locking position of the locking element (15), and the recess defines the release position of the locking element (15).

9. The chain magazine according to claim 2, characterized in that The control bolt (10) has an undercut (18) pointing in the opening direction (17) of the control bolt (10), and the locking element (15) abuts against the undercut in the locking position.

10. The chain magazine according to claim 1 or 2, characterized in that The locking device (14) of the tool gripper (5) is designed as a centrifugal locking device which has a locking element that is in the release position when the closed tool gripper (5) moves along a non-curved chain section (3b) and moves radially outwards from the release position against the action of a restoring force to the locking position due to centrifugal force when the closed tool gripper (5) moves along a curved chain section (3a).

11. The chain magazine according to claim 1 or 2, characterized in that Two pivotable jaws (9) are provided, which are pivotably supported about parallel pivot axes (8), wherein a control bolt (10) is arranged centrally between the two jaws (9) and is arranged with its bolt axis at right angles to the plane spanned by the two parallel pivot axes (8).

12. The chain magazine according to claim 1 or 2, characterized in that One or two adjacent link members (4) are designed as tool grippers (5).

13. The chain magazine according to claim 1 or 2, characterized in that None of the two link members (4) is designed as a tool gripper.

14. The chain magazine according to claim 1 or 2, characterized in that The chain plane defined by the magazine chain (3) extends at least sectionally in a vertical plane.

15. The chain magazine according to claim 4, characterized in that The at least one locking element (15) is able to move from the release position to the locking position against the action of a return spring (16).

16. The chain bin according to claim 5, characterized in that, The locking element (15) is able to be guided at right angles to the bolt axis of the control bolt (10) between the release position and the locking position.

17. The chain bin according to claim 14, characterized in that, The chain plane defined by the magazine chain (3) extends completely in a vertical plane.

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