CN113021042B

CN113021042B - Lever balance tensioning clamp and using method thereof

Info

Publication number: CN113021042B
Application number: CN202110326040.5A
Authority: CN
Inventors: 陈伟; 张帆; 石尚; 纪欢欢; 钱子栋
Original assignee: AVIC Landing Gear Advanced Manufacturing Corp
Current assignee: AVIC Landing Gear Advanced Manufacturing Corp
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2022-05-03
Anticipated expiration: 2041-03-26
Also published as: CN113021042A

Abstract

The invention provides a lever balance tensioning clamp and a using method thereof. The lever balance tensioning clamp comprises a base body, a chuck and a lever support frame, and a tensioning cavity is formed between the lever support frame and the base body; the connecting line of the chuck and the lever supporting frame is in the X direction, and the tensioning cavity is provided with a through opening on the projection planes in the X direction and the Y direction; the hinged shaft of the lever support frame is parallel to the Y direction; the clamping head is provided with a first abutting point protruding towards the tensioning cavity in the X direction, the lever support frame is provided with two second abutting points protruding towards the tensioning cavity in the X direction, and the two second abutting points and the first abutting point are connected to form a triangle. Compared with the prior art, the lever balance tensioning clamp provided by the invention balances the pressing force of the lever support frame through the lever principle, and eliminates the distortion caused by unbalanced external force of the clamp on the die forging.

Description

Lever balance tensioning clamp and using method thereof

Technical Field

The invention relates to the technical field of machining, in particular to a lever balance tensioning clamp and a using method thereof.

Background

In the mechanical industry, in order to ensure the strength of parts, the mechanism is often designed into an integral forming structure, which leads to the appearance of the parts to be more and more complex, brings much inconvenience to mechanical processing, and is particularly prominent in the aspect of clamping. In the production process, in order to save materials and control the cost, the die forging is generally selected as the machined blank. Both ends of the forging have no parts for clamping a chuck of a machine tool, so that a part must be fixed in a clamp tensioning mode. If the balance of the tension force is not considered when the clamp is designed, unbalance of the internal clamping stress of the part is caused, and finally the part is easy to bend and deform after being processed, so that the product quality is influenced.

The prior art clamping apparatus is a multi-point conformal clamping apparatus for blank surfaces, as disclosed in patent publication No. CN107097088A, which uses a centering mechanism and a rotating arm to clamp the blank surfaces of castings and die forgings. Such symmetrical clamping devices are not suitable for complex part shapes.

Disclosure of Invention

The invention aims to provide a lever balance tensioning clamp and a using method thereof, which are used for clamping a die forging.

The technical scheme of the invention is as follows: a lever balance tensioning clamp is provided with an X direction and a Y direction which are vertical to each other on the same projection plane, and comprises a base body, a chuck arranged at one end of the base body and used for clamping a machine tool chuck, and a lever support frame hinged to the other end of the base body, wherein a tensioning cavity is formed between the lever support frame and the base body; the connecting line of the chuck and the lever supporting frame is in the X direction, and the tensioning cavity is provided with a through opening on the projection planes in the X direction and the Y direction; the hinged shaft of the lever support frame is parallel to the Y direction; the clamping head is provided with a first abutting point protruding towards the tensioning cavity in the X direction, the lever support frame is provided with two second abutting points protruding towards the tensioning cavity in the X direction, and the two second abutting points and the first abutting point are connected to form a triangle.

In the scheme, a stable triangular clamping structure is formed in the lever balance tensioning clamp, and the lever balance tensioning clamp can swing relative to the base body by combining the second abutting point, so that the lever balance tensioning clamp can adapt to the shape of a complex part, can balance the pressing force of the lever support frame, and eliminates the deformation of the part caused by the external force of the clamp on the workpiece.

Preferably, the lengths of the two second abutment points projecting into the tensioning chamber are adjustable in the direction in which they project, respectively. By designing the adjustable mode of the second abutting point, the part freedom degree is further limited to achieve the purpose of firm clamping while the pressing force is balanced.

Preferably, the chuck is a stepped shaft having a large-diameter section and a small-diameter section, the small-diameter section is connected to the base, and a tip protruding toward the tensioning cavity is provided on the small-diameter section, and the end of the tip is the first contact point.

The chuck of design stair structure on the one hand makes things convenient for locomotive chuck centre gripping, on the other hand, be convenient for with the installation of base member, just the position of chuck easily forms the first butt point with the work piece butt, for the taut important condition that provides of die forging.

Preferably, the base body is provided with third abutting points protruding towards the tensioning cavity in the Y direction, and at least two third abutting points are arranged on the opposite sides of the base body.

The lever balance tensioning clamp is not only designed into a triangular abutting point, but also is additionally provided with two abutting points on the outer side of the triangle, so that the tensioning force is further balanced, the clamping stress inside a die forging piece can be balanced, and the bending deformation is reduced.

Preferably, the base body comprises a foundation plate, a support, a rib plate and a boss, the support is horizontally connected to two ends of the foundation plate, and one end, far away from the foundation plate, of the support is hinged to the lever support frame; the connecting line of the brackets at the two ends is parallel to the Y direction of the lever balance tensioning clamp; the rib plate is connected with the support and the foundation plate, and the rib plate and the support form the side wall of the tensioning cavity together; the boss is arranged on one side, facing the tensioning cavity, of the rib plate, and the third abutting point is arranged on the boss.

The above-mentioned structural design of base member can form stable rigid structure, makes the butt power of anchor clamps effective, and the tensioning force that produces satisfies the design requirement.

Preferably, a threaded hole is formed in the boss, a ball screw is connected with the threaded hole in a threaded manner, and the ball screw forms the third abutting point.

The ball screw has the characteristic of surface-point contact, and when the ball screw is screwed to abut against the surface of a workpiece, the abutting effect can be realized no matter how the surface of the workpiece is shaped.

Preferably, the device further comprises a counterweight, wherein the counterweight is arranged on the base body and is positioned on the same side as the third abutting point.

The balance weight can keep the balance of the clamp after clamping the workpiece.

Preferably, the lever support frame comprises a lever, a pressing plate and a compression screw, the lever is hinged to the base body, the pressing plate is connected to two ends of the lever, the compression screw axially stretches towards the tensioning cavity and is in threaded connection with the pressing plate, and the compression screw forms the second abutting point.

Preferably, the middle part of the pressure plate is convexly provided with a lug; in the pressing plates at the two ends of the lever, the convex block of the pressing plate at one end faces the tensioning cavity, and the convex block of the pressing plate at the other end faces away from the tensioning cavity.

The invention also provides a use method of the lever balance tensioning clamp, which comprises the following steps:

1) arranging two process bosses on one side of the die forging, and arranging a center hole on the other side, wherein the center hole is arranged close to the middle parts of the two process bosses;

2) clamping a chuck of the lever balance tensioning clamp by a machine tool chuck;

3) extending the die forging into the tensioning cavity from the opening, and abutting the first abutting point with the tip hole;

4) the lever support frame swings along the hinge point of the lever support frame, so that two second butt points on the lever support frame are respectively abutted with the two process bosses to form tensioning.

Compared with the related technology, the invention has the beneficial effects that:

firstly, the clamping problem during turning of the die forging is solved through a self-made chuck of the stepped shaft;

secondly, the die forging is tensioned through a first abutting point (tip) and a second abutting point (pressing plate and pressing screw) which are designed to form a triangular connecting line, the degree of freedom of the die forging is limited, and the purpose of firm clamping is achieved;

balancing the pressing force of the lever support frame through a lever principle, and eliminating the distortion caused by the unbalanced external force of the fixture on the die forging;

and fourthly, designing a third abutting point, and realizing the abutting effect no matter how the surface shape of the workpiece is when the ball head screw is screwed to abut against the surface of the die forging through the surface point contact characteristic of the ball head screw.

Drawings

Fig. 1 is a schematic perspective view of a lever balance tensioning clamp according to the present invention;

FIG. 2 is a schematic view of FIG. 1 taken along line A;

FIG. 3 is a schematic sectional view taken along line B-B of FIG. 2;

FIG. 4 is a schematic structural view of a die forging used for clamping by the lever balance tensioning clamp provided by the invention;

fig. 5 is a schematic sectional structure view of the lever balance tension clamp provided by the invention after being clamped with a die forging.

In the drawings: the clamping head comprises a clamping head 1, a base body 2, a ball screw 3, a balance weight 4, a lever 5, a pressing plate 6, a compression screw 7, a smooth pin 8, a lever supporting frame 9, a workpiece 10, a machine tool chuck 11, a boss 21, a support 22, a groove 23, a base plate 24, a rib plate 25, a tensioning cavity 26, a third abutting point 27, a first abutting point 101, a second abutting point 91, a tip hole 102 and a process boss 103.

Detailed Description

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. For convenience of description, the words "upper", "lower", "left" and "right" in the following description are used only to indicate the correspondence between the upper, lower, left and right directions of the drawings themselves, and do not limit the structure.

As shown in fig. 1, the lever balance tightening clamp provided in this embodiment has an X direction and a Y direction perpendicular to each other on the same projection plane, where the projection plane is a projection plane in the a direction, and the projection plane is a Z direction in the top view of fig. 1.

The lever balance tensioning clamp comprises a base body 2, a chuck 1 arranged at one end of the base body 2 and used for clamping a machine tool chuck, a lever support frame 9 hinged to the other end of the base body 2, and a balance weight 4 arranged on the base body 2. A tensioning cavity 26 is formed between the lever supporting frame 9 and the base body 2. The connecting line of the chuck 1 and the lever supporting frame 9 is in the X direction, and the tensioning cavity 26 is provided with a through opening on the projection plane in the X direction and the Y direction.

As shown in fig. 2, 3 and 5, the chuck 1 has a stepped cylindrical shape including a tip, a small diameter section and a large diameter section connected in sequence. The large diameter section is clamped with a machine tool chuck 11. A plurality of threaded holes which are circumferentially arranged are arranged on the step surface formed by the large-diameter section and the small-diameter section. The small-diameter section is connected with the base body 2, the tip protruding towards the tensioning cavity 26 is arranged on the small-diameter section, the tip protrudes towards the tensioning cavity 26 in the X direction, and the tail end of the tip is provided with a first abutting point 101.

As shown in fig. 1, 2 and 3, the base body 2 includes a base plate 24, a bracket 22, a rib plate 25 and a boss 21. The lever support frame 9 comprises a lever 5, a pressure plate 6 and a compression screw 7.

The bracket 22 is horizontally connected to both ends of the base plate 24 in the Y direction by welding. One end of the support 22 far away from the base plate 24 is provided with a groove 23. The lever 5 of the lever support 9 is of a C-shaped construction, the C-shaped opening of which is arranged facing away from the tensioning chamber 26. The middle of the C-shaped lever 5 is placed in the groove 23 and hinged to the bracket 22. The specific mode of articulated is: the middle part of the lever 5 is provided with a unthreaded hole, and the bracket 22 is provided with a threaded hole. The lever 5 and the support 22 are connected through the support 22 and the unthreaded hole by the smooth surface pin 8 with one end being a thread and the other end being a polished rod, wherein one end of the smooth surface pin 8 with the thread is matched with the threaded hole on the support 22, and one end of the smooth surface pin 8 with the polished rod is matched with the unthreaded hole of the lever 5, so that the lever support frame is hinged with the base body. And the hinge axis is parallel to the Y direction. The connecting line of the brackets 22 at the two ends is parallel to the Y direction of the lever balance tensioning clamp.

Threaded holes are formed in two ends of the C-shaped structure of the lever 5, and the pressing plates 6 are mounted through fastening screws respectively. The middle part of the pressing plate 6 protrudes and extends with a convex block 61. In the pressing plates 6 at the two ends of the lever 5, the convex block 61 of the pressing plate 6 at one end is arranged towards the tensioning cavity 26, and the convex block 61 of the pressing plate 6 at the other end is arranged back to the tensioning cavity 26. Thus, the left base plate 24, the upper and lower brackets 22 and the rib plates 25, and the right pressing plate 6 enclose the tensioning cavity 26 (shown in fig. 1).

The lug 61 is provided with a threaded hole, and is connected with the threaded hole through a compression screw 7 with threads on the excircle. The end of the compression screw 7 projecting into the tightening cavity 26 forms the second abutment point 91 of the lever balancing tightening clamp. The compression screw 7 can freely move in the threaded hole of the pressure plate 6 in an axially telescopic manner through threaded fit, so that the length of the two second abutting points 91 protruding into the tensioning cavity 26 can be adjusted along the protruding direction of the two second abutting points respectively, so as to adapt to the appearance of a workpiece and compress the workpiece.

As shown in fig. 1 and 2, the rib plate 25 connects the bracket 22 and the base plate 24 in the Z direction, and is disposed on both sides of the bracket 22. The webs 25 and the support frame 22 together form the side walls of the tensioning chamber 26. As shown in fig. 2 and 3, the rib plate 25 is provided with the boss 21 on the side facing the tightening cavity 26. The boss 21 is provided with a threaded hole, the threaded hole is connected with the ball screw 3 in a threaded manner, and the ball screw 3 forms a third abutting point 27 of the lever balance tensioning clamp. Two third contact points 27 are provided, and are arranged to face each other in the Y direction. If the number of the third abutting points 27 is three, two rib plates 25 on one side are arranged at intervals, and if the number of the third abutting points 27 is four, two rib plates 25 on two sides are arranged at intervals, and so on.

One end of the ball screw 3 is a spherical surface, threads are arranged on the outer circle, and the ball screw 3 can freely move in the threaded hole of the boss 21 through the thread matching, so that the workpiece (die forging) 10 is pushed tightly.

As shown in fig. 3, the counterweight is a plate, the plate is provided with a threaded hole connected with the base plate 24, and the counterweight is fixed on the base plate through a fastener (screw or bolt). The counterweight 4 is located on the same side as the third abutting point 27. The detachable structure of the balance weight 4 can actually change different weight models according to the needs.

As shown in fig. 1, the two second abutting points 91 of the lever balance tensioning clamp are connected with the first abutting point 101 to form a triangle.

As shown in fig. 3, the base plate 24 is provided with a positioning hole matching with the small diameter section of the chuck 1. And foundation screw holes are uniformly formed in the foundation plate 24 in a circumferential manner around the positioning holes, the foundation screw holes correspond to the screw holes in the step surface of the chuck 1 in position, and the foundation plate 24 is connected with the chuck 1 through fasteners.

1) the die forging (workpiece 10) in this embodiment is a typical landing gear strut-like part, provided with a clamped section and a non-clamped section (machined section). A tip hole 102 is processed on one side (the left side shown in fig. 4) of the clamping section, and two process bosses 103 are reserved on the other side (two side faces of the inclined shaft). The center hole 102 is disposed near the middle of the two process bosses 103, that is, the distance from the center of the two process bosses 103 to the center line of the workpiece 10 is equal, and the center hole 102 is coaxial with the center line of the workpiece 10 (as shown in fig. 4).

2) The large diameter section of the collet 1 of the lever balancing tensioning clamp is clamped by a machine tool chuck 11, and at the same time, the two press plates 6 on the lever support frame 9 are removed.

3) And (3) extending the die forging into the tensioning cavity 26 from the opening, and abutting the first abutting point 101 with the tip hole 102 to realize that the non-clamping section of the workpiece is coaxial with the machine tool. The non-clamping section of the die forging extends out of the tensioning cavity 26 (as shown in fig. 5) between the two levers 5. At this time, the upper and lower third abutting points 27 of the lever balance tension jig abut against the outer end surface of the die forging.

4) Installing a pressing plate 6: the projection 61 of one of the pressure plates 6 is arranged facing the tensioning chamber 26, and the other projection 61 is arranged facing away from the tensioning chamber 26.

5) A compression screw 7 is mounted in the threaded hole of the boss 61. Because the lever support frame 9 swings along the hinge point, the two second abutting points 91 on the lever support frame are respectively abutted with the two process bosses 103 after being self-adaptively adjusted. And adjusting the compression screw 7 to enable the two second abutting points 91 and the first abutting point 101 to form a stable tensioning structure so as to compress the die forging and complete tensioning and clamping of the die forging.

Because the distance from the center of the two process bosses 103 to the center line of the workpiece 10 is equal, when the compression screw 7 contacts the process bosses 103, the two sides can be ensured to have equal moment. Because the lever 5 is hinged with the bracket 22 through the smooth pin and can rotate freely, if the pressing pin 7 on the pressing plate 6 on one side of the workpiece contacts the process boss 103 first, the lever 5 rotates until the pressing screws 7 on the pressing plates 6 on two sides contact the process boss 103. The effect of preventing the rotation of the parts due to uneven stress can be achieved.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A lever balance tensioning clamp is provided with an X direction and a Y direction which are vertical to each other on the same projection plane, and is characterized by comprising a base body (2), a chuck (1) arranged at one end of the base body (2) and used for clamping a machine tool chuck, and a lever support frame (9) hinged to the other end of the base body (2), wherein a tensioning cavity (26) is formed between the lever support frame (9) and the base body (2); a connecting line between the chuck (1) and the lever support frame (9) is in the X direction, and a through opening is formed in a projection plane of the tensioning cavity (26) in the X direction and the Y direction; the hinged shaft of the lever support frame (9) is parallel to the Y direction; a first abutting point (101) protruding towards the tensioning cavity (26) in the X direction is arranged on the chuck (1), two second abutting points (91) protruding towards the tensioning cavity (26) in the X direction are arranged on the lever support frame (9), and a connecting line of the two second abutting points (91) and the first abutting point (101) forms a triangle;

the base body (2) is provided with at least two third abutting points (27) protruding towards the tensioning cavity (26) in the Y direction, and the third abutting points (27) are arranged on the opposite sides of the base body (2);

the base body (2) comprises a foundation plate (24), a support (22), a rib plate (25) and a boss (21), the support (22) is horizontally connected to two ends of the foundation plate (24), and one end, far away from the foundation plate (24), of the support (22) is hinged to the lever support frame (9); the connecting line of the brackets (22) at the two ends is parallel to the Y direction of the lever balance tensioning clamp; the rib plate (25) is connected with the support (22) and the foundation plate (24), and the rib plate (25) and the support (22) jointly form a side wall of a tensioning cavity (26); the boss (21) is arranged on one side, facing the tensioning cavity (26), of the rib plate (25), and the third abutting point (27) is arranged on the boss (21);

lever support frame (9) include lever (5), clamp plate (6) and housing screw (7), lever (5) with base member (2) are articulated, clamp plate (6) are in the both ends of lever (5) are connected, threaded connection goes up to clamp plate (6) has to take up chamber (26) axial flexible housing screw (7), housing screw (7) form second butt point (91).

2. The lever balance tensioning clamp according to claim 1, characterized in that the length of projection of the two second abutment points (91) into the tensioning cavity (26) is adjustable in the direction of projection thereof, respectively.

3. The balanced lever tensioning clamp according to claim 1 or 2, characterized in that the collet (1) is a stepped shaft having a large-diameter section and a small-diameter section, the small-diameter section being connected to the base body (2) and being provided with a tip projecting towards the tensioning cavity (26) at the small-diameter section, the tip terminating in the first abutment (101).

4. The lever balanced tensioning clamp according to claim 1, characterized in that the boss (21) is provided with a threaded hole, which is internally threaded with a ball screw (3), the ball screw (3) forming the third abutment point (27).

5. The lever balance tensioning clamp according to claim 1, further comprising a counterweight (4), said counterweight (4) being provided on said base body (2) on the same side as said third abutment point (27).

6. The lever balance tensioning clamp according to claim 1, wherein a projection (61) is projected from the middle of the pressure plate (6); in the pressure plates (6) at the two ends of the lever (5), a convex block (61) of the pressure plate (6) at one end is arranged towards the tensioning cavity (26), and a convex block (61) of the pressure plate (6) at the other end is arranged back to the tensioning cavity (26).

7. A method of using the lever balanced tensioning clamp of any one of claims 1 to 6, including:

1) arranging two process bosses (103) on one side of the die forging, arranging a tip hole (102) on the other side, wherein the tip hole (102) is arranged close to the middle parts of the two process bosses (103);

2) clamping a chuck (1) of the lever balance tensioning clamp by a machine tool chuck (11);

3) extending the die forging into the tensioning cavity (26) from the opening, and abutting the first abutting point (101) with the tip hole (102);

4) the lever supporting frame (9) swings along the hinge point, so that two second abutting points (91) on the lever supporting frame are respectively abutted with the two process bosses (103) to form tensioning.