Split type clamp for finish turning
Through the positioning disc and positioner structure of the Jingche split fixture, the problem of the existing lathe fixture requiring additional fixtures in the processing of non-circumferential workpieces is solved, and cost reduction and processing efficiency improvement is achieved.
Patent Information
- Application Number
- CN202510588489.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2025-07-22
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing lathe fixtures require additional transition fixtures when processing non-circumferential workpieces, resulting in high costs, long cycles and complex management.
A fine-car split fixture is designed, adopting a positioning disc and a positioner structure, and is linked with the first jaw through the spiral transmission of the positioning disc, combining the positioning block and the positioner to achieve fixation of non-circumferential workpieces and reduce the use of transition fixtures.
It reduces the cost of fixtures, simplifies the preparation process for workpiece processing, and improves processing efficiency and energy-saving effects.
Smart Images
Figure CN120347241A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of lathe clamps, in particular to a precision lathe split clamp. Background Art
[0002] A lathe is a machine tool that uses a turning tool to turn a rotating workpiece. It is the most important type of metal cutting machine tool. In general machine manufacturing factories, lathes are the most numerous and are also called mother machines.
[0003] When machining a workpiece, the lathe needs to clamp the workpiece from one end and rotate it. For slender workpieces, the tailstock is used from the other end to improve stability. The most common clamping fixture at the spindle is the classic three-jaw chuck, such as Figure 1 The three-jaw chuck can adjust the position of the claw tip by a wrench on the outer circumference of the chuck body, so as to clamp workpieces of different sizes. However, the three-jaw chuck also has certain limitations. If the surface circumference of the workpiece is too small and the three jaws cannot be on the circumference of the same diameter, the three-jaw chuck cannot be used to fix the workpiece. It is necessary to make an additional non-standard fixture to clamp the workpiece and then clamp it on the three-jaw chuck. This will not only produce more types of fixtures, but the more fixtures there are, the more costs will be incurred for their production, maintenance and management. It is also necessary to make fixtures in advance before processing parts, which will extend the product cycle. For this reason, we propose a split fixture for precision turning. Summary of the invention
[0004] The object of the present invention is to provide a fine turning split fixture to solve the problems raised in the above background technology.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a precision turning split clamp, comprising a chuck body, a first jaw and two second jaws are provided on the end face of the chuck body for radial sliding, the first jaw and the second jaw are evenly distributed on the circumference of the end face, a rotating shaft is symmetrically provided on both sides of the first jaw on the end face of the chuck body, a positioning disk is fixed on the rotating shaft, a section of the circumferential side wall of the positioning disk is in the shape of a spiral line, and the rotating shaft is transmission-connected to the first jaw, a positioning block is elastically slidably provided on the inner wall of the positioning end of the first jaw, the positioning disk rotates when the first jaw moves radially outward, and the outer edge of the positioning disk is at a point closest to the axis of the chuck body, which point is on the spiral side wall and is on the same circumferential diameter with the end of the positioning block as the center, and a locator is provided between the two groups of second jaws to resist the workpiece.
[0006] Preferably, the positioning plate is slidably sleeved and fixed along the axial direction of the rotating shaft, and the two cannot rotate relative to each other, and the outer circumferential side wall of the positioning plate is symmetrically arranged along the axial plane of the rotating shaft.
[0007] Preferably, the locator includes two turntables rotatably connected to each other. A pull rod is slidably provided on each turntable. One end of the pull rod is hinged to the side wall of the chuck body or the second jaw. A limit nut is threadedly connected to the other end of the pull rod. A locking block is fixed to the outer end face of the turntable.
[0008] Preferably, the locking block is fixedly installed on the turntable, and a plane is provided on the side wall of the locking block. At least two hemispheres passing through the center of the sphere are slidably embedded on one side of the plane of the locking block.
[0009] Preferably, the end of the pull rod is detachably connected to the chuck body or the second jaw.
[0010] Preferably, the pull rod is flat, and threads are provided on the arc-shaped surfaces on both sides for connection with the limit nut.
[0011] Preferably, multiple groups of positioning disks are provided, and different positioning disks are used for positioning workpieces with different outer diameters.
[0012] Preferably, the centers of the hemispheres are located on the same axis along the axial direction of the turntable.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: By providing the positioning disk and the locator, the present invention can fix the workpiece surface of the lathe that cannot be directly fixed by the three-jaw chuck due to non-circular surfaces, and there is no need to design a set of transition jigs. This can not only reduce costs but also achieve a certain degree of energy-saving purpose because the overall quality is smaller. The positioning structure of the present invention can be disassembled from the chuck body, does not affect the normal positioning of the three jaws, can be separated, and can be installed when needed, which is convenient and practical. The adjustment of the present invention is integrated with the original adjustment method of the three jaws, and the operation method remains basically unchanged, which is more conducive to use. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a schematic diagram of the overall structure of the three-jaw chuck; Figure 2 It is a schematic diagram of the structure of the present invention; Figure 3 It is a schematic diagram of the rotational view structure of the positioning disk of the present invention; Figure 4 It is a cross-sectional view of the first jaw; Figure 5 It is a positioning view of the spiral line of the positioning disk at different positions; Figure 6 It is a schematic diagram of an embodiment of one of the transmission structures; Figure 7 It is a schematic diagram of the structure at the locator; Figure 8For Figure 7 front view of Figure 9 Schematic cross-sectional view of the drawbar in a flat shape and the limit nut; Figure 10 Schematic view of the limit of the hemisphere.
[0015] In the figure: 1 - chuck body; 2 - first jaw; 3 - second jaw; 4 - rotating shaft; 5 - positioning disk; 6 - positioning block; 7 - positioner; 8 - turntable; 9 - drawbar; 10 - limit nut; 11 - locking block; 12 - hemisphere; 13 - first gear; 14 - second gear; 15 - third gear; 16 - first rack; 17 - connecting rod; 18 - second rack; 19 - fourth gear. Specific embodiments
[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0017] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , the present invention provides a technical solution: a precision turning split fixture, including a chuck body 1, Figure 1 is a three-jaw chuck structure in the prior art. Three jaws are evenly distributed on the chuck body 1. The jaws are driven and adjusted through the adjustment knob on the chuck body 1 and can be self-locked. The ends of the three jaws are always located on the same radial line (i.e., on the circular line with the center line of the chuck body 1 as the axis). It is precisely because the three jaws are synchronized that for some workpieces with non-complete circumferential surfaces, the three jaws cannot be fixed synchronously anymore. Similarly, some existing four-jaw chucks have the same problem. In this solution, on the basis of the three-jaw chuck, the three jaws are divided into two categories, the first jaw 2 and the second jaw 3. The structures of the two types of jaws are exactly the same, only for classification description and adding structures on the side walls. The positioning disk 5 is arranged on both sides of the first jaw 2 and is located between the first jaw 2 and the second jaw 3. The positioning disk 5 is rotatably installed on the chuck body 1 through the rotating shaft 4. At least one circumferential side wall of the positioning disk 5 is spiral ( Figure 2The thickened line), and the positioning disk 5 is linked with the first claw 2 through a transmission mechanism. That is, during the outward movement of the first claw 2, the positioning disk 5 rotates. The positioning disk 5 continuously changes the point on its outer edge that is closest to the axis of the chuck body 1, so that the tangent at this point is the same as the tangent direction of the circle with the perpendicular line from this point to the chuck body 1 as the diameter at this point. The two groups of positioning disks 5 can be designed asymmetrically, but this will make the processing and design more complex. Therefore, the two groups of positioning disks 5 are designed symmetrically. Since three points determine a circle center, a groove is opened at the end of the first claw 2, and a spring is arranged in the groove. The outer end of the spring is connected with a positioning block 6 that slides in the groove. By the method of determining the circle with the three points of the end of the positioning block 6 and the two fixed disks 5, the circular outer peripheral surface of a part of the workpiece can be placed at the position of the first claw 2 for positioning. The positions of the above three points are too close, and the included angle between them is too small to fix the workpiece. Therefore, a positioner 7 is provided for fixing, and the positioner 7 is arranged at the position between the two second claws 3; The positioning range corresponding to a single positioning disk 5 is relatively small. Therefore, multiple groups of positioning disks 5 at different positions can be set to improve the applicability; As one of the embodiments, the transmission mechanism between the positioning disk 5 and the first claw 2 includes a first rack 16 fixed to the side wall of the first claw 2. A first gear 13 synchronized with the positioning disk 5 is fixed on the rotating shaft 4, and a second gear 14 meshing with the first gear 13 is also rotatably connected to the chuck body 1. A third gear 15 meshing with the first rack 16 is also fixed on the shaft where the second gear 14 is located. Under this transmission mechanism, because three points are required to determine a circle, the positioning block 6 needs to move a certain distance outside the first claw 2 before it can match the positioning disk 5. Therefore, an empty stroke movement is required first, that is, the first rack 16 first moves outward a certain distance and then meshes with the third gear 15. The outer diameter L of the workpiece with the smallest size that can be positioned in the just-meshed state is shown as Figure 5 shown. The corresponding point is A1. The first claw 2 moves outward by a unit distance △L. The diameter of the second point is L + △L, and the corresponding point is B2 (A2 in the A1 state rotates to correspond to B2). Subsequently, in turn, it can be obtained that the rotation angle of the positioning disk 5 decreases successively. Therefore, the transmission ratio between the first gear 13 and the second gear 14 is not a fixed value. This transmission ratio is related to the parameters of the spiral line of the spiral section. A polar coordinate can be constructed, with the focus of the axis of the rotating shaft on the surface of the chuck body 1 as the coordinate origin, and in the horizontal or vertical direction ( Figure 5For the state shown, a coordinate system is established for the polar axis to construct an equation. On the other hand, in the Cartesian coordinate system, the coordinates of points A1, B2, B3, B4, and B5 are related to L, ΔL, and the angle θ. Since L and ΔL are fixed values, the θ values of each point can be obtained. Combining with the polar coordinate equation, the variables of the equation in the polar coordinate system can be determined, and the helix equation can be obtained. In the case of determining the helix equation, the positioning disk 5 is driven by the first gear 13 and the second gear 14. The non-fixed transmission ratio of the first gear 13 and the second gear 14 is realized by using a nautilus gear. The spiral surface of the nautilus gear is adaptively and correspondingly arranged with the above-mentioned helix to change the transmission ratio; As another embodiment, the transmission mechanism between the positioning disk 5 and the first jaw 2 includes a fourth gear 19 fixed on the rotating shaft 4, and a second rack 18 meshing with the fourth gear 19 is slidably arranged on the chuck body 1. One end of the second rack 18 is hinged with a connecting rod 17, and the other end of the connecting rod 17 is slidably arranged on the chuck body 1, and the sliding direction is the same as the moving direction of the first jaw 2. After the first jaw 2 moves through the idle stroke, it catches and drives the end of the connecting rod 17 to move, thereby pushing the second rack 18 at the other end to move, so as to realize the rotation of the fourth gear 19 by a non-fixed angle, and also realize the non-fixed transmission ratio; The positioner 7 is mainly used for another support point. A plurality of threaded holes can be arranged in the area between the two second jaws 3, and a disk is fixed by using screws or bolts to press the workpiece. The positions of the multiple threaded holes can be changed, and the size of the disk can be adapted to workpieces of different sizes. A nut can also be fixed on the chuck body 1, and a bolt is screwed on the nut as a fixing method. Preferably, the axis of the nut intersects with the axis of the chuck body 1, and the fixing position can be adjusted by screwing the bolt on the nut.
[0018] In the above-mentioned various embodiments, each transmission structure can be arranged at a position below the end face of the chuck body 1, because such structures are only used to change the rotation angle of the positioning disk 5. Only the positioning disk 5 needs to protrude beyond the upper end face of the chuck body 1 for positioning. Therefore, when the three jaws are normally positioned, the structures for non-complete circumferential positioning such as the positioning disk 5 can be removed. Therefore, the positioning disk 5 is arranged to be slidable and detachably fixed in the axial direction of the rotating shaft 4; Furthermore, for the axial sliding and disassembly of the positioning disk 5, generally, limits are set on the rotating shaft 4, and they are usually symmetric. To avoid incorrect installation, the outer peripheral side wall of the positioning disk 5 is set to be symmetric, that is, two helical lines (not shown in the figure) are provided as a way of anti-fooling.
[0019] Refer to Figure 2 、 Figure 3 、 Figure 7 、 Figure 8 and Figure 10, in the above-described embodiments of the locator 7, they are all relatively fixed. Whether it is by bolts or by means of a disc, their positions are relatively fixed, while the other is relatively fixed in terms of angle. In order to achieve better fixation, the present application proposes another specific embodiment. A turntable 8 is provided at the position between the two second jaws 3. The turntable 8 is divided into two layers, and a pull rod 9 is slidably provided on each layer. The two pull rods 9 form a cross shape. The other ends of the two pull rods 9 can be pivotally connected to the side wall of the second jaw 3 or to the upper surface of the chuck body 1. Since the two layers of the turntable 8 can rotate relative to each other and slide on the pull rod 9, the position can be arbitrarily changed. The locking block 11 can be fixed on the upper end surface or the lower end surface of the turntable 8, or can be provided at both ends. Preferably, it is fixed on the upper end surface. And at the end of the pull rod 9 after passing through the turntable 8 (relative to the end connected to the chuck body 1 or the second jaw 3), a limit nut 10 is threadedly connected. Only after being limited and cooperating with the positioning disc 5 can it play a fixing role; To improve the adaptability of the locking block 11 to the surface of the workpiece, as Figure 7 shown, at least more than half of the hemispheres 12 are embedded in the locking block 11, and the embedded side walls are parallel. Similarly, the side walls of the non-spherical surfaces of the two hemispheres 12 are also flat surfaces. The two hemispheres 12 can adaptively adjust the angle according to the surface of the workpiece to fit the surface, as Figure 10 shown; Furthermore, the locking block 11 is fixedly installed on the turntable 8 through structures such as bolts. The normal direction of the plane of the locking block 11 can be adjusted by tightening or loosening the bolts, so that the hemispheres 12 can better fit the surface of the workpiece. Similarly, when abnormal positioning is not required, the locator 7 is not needed. Therefore, the end of the pull rod 9 is set to be sleeved on the shaft and can be taken out axially. When not in use, it can be directly removed without affecting normal positioning. Refer to Figure 9 , because the pull rod 9 needs to ensure the fixing strength, it needs to have a certain diameter. This will result in a relatively high positioning height of the hemispheres 12 from the upper surface of the chuck body 1 after superposition. Therefore, the pull rod 9 is set to be flat and retains two arc-shaped side surfaces. The arc-shaped side surfaces are used to construct threads, and then the limit nut 10 is sleeved for limiting. Because when fixing the workpiece, the forces received by the pull rod 9 are all in the plane direction parallel to the end surface of the chuck body 1, the axial thickness of the pull rod 9 on the chuck body 1 can be appropriately reduced.
[0020] In practical use, first rotate the chuck body 1 so that the first jaw 2 is in the lowermost position, and then adjust the positions of the three jaws to the nearest outermost position by turning the adjustment knob (the size of the workpiece can be judged visually to roughly position the jaws), and then place the arc outer circumference of the workpiece correspondingly on the positioning plate 5. The two positioning plates 5 will support the workpiece. At this time, if the positioning block 6 is in a natural state and does not touch the workpiece, it means that the axis of the workpiece deviates from the axis of the chuck body 1, and the jaws need to be adjusted back so that the positioning block 6 on the first jaw 2 just touches the workpiece and the spring is not compressed. At this time, the position is just right, and then adjust the position of the positioner 7 to fix it.
[0021] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.
[0022] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. Precision turning split fixture, including a chuck body (1), a first jaw (2) and two second jaws (3) are slidably arranged radially on the end face of the chuck body (1), and the first jaw (2) and the second jaws (3) are evenly distributed in the circumferential direction of the end face. It is characterized in that: On the end face of the chuck body (1), rotating shafts (4) are symmetrically arranged on both sides of the first jaw (2). A positioning disk (5) is fixed on the rotating shaft (4). A circumferential side wall of a section of the positioning disk (5) is spiral-shaped, and a transmission connection is provided between the rotating shaft (4) and the first jaw (2). A positioning block (6) is elastically slidably arranged on the inner wall of the positioning end of the first jaw (2). When the first jaw (2) moves radially outwards, the positioning disk (5) rotates. And at a point on the outer edge of the positioning disk (5) that is closest to the axis of the chuck body (1), this point is on the spiral side wall, and is on the same circumferential diameter centered on the axis of the chuck body (1) as the end of the positioning block (6). A positioner (7) for pressing against the workpiece is provided between two groups of second jaws (3).
2. The precision turning split fixture according to claim 1, wherein: The positioning disk (5) is slidably sleeved and fixed along the axial direction of the rotating shaft (4), and the two cannot rotate relative to each other. The outer circumferential side wall of the positioning disk (5) is symmetrically arranged along a plane passing through the axis of the rotating shaft (4).
3. The precision turning split fixture according to claim 1, characterized in that: The positioner (7) includes two rotatably connected turntables (8). A pull rod (9) is slidably arranged on each turntable (8). One end of the pull rod (9) is hinged to the side wall of the chuck body (1) or the second jaw (3). A limit nut (10) is threadedly connected to the other end of the pull rod (9). A locking block (11) is fixed on the outer end face of the turntable (8).
4. The precision turning split fixture according to claim 3, wherein: The locking block (11) is fixedly installed on the turntable (8), and a plane is provided on the side wall of the locking block (11). At least two hemispheres (12) passing through the center of the sphere are slidably embedded on one side of this plane of the locking block (11).
5. The precision turning split fixture according to claim 3 or 4, characterized in that: The end of the pull rod (9) is detachably connected to the chuck body (1) or the second jaw (3).
6. The precision turning split fixture according to claim 3, characterized in that: The pull rod (9) is flat, and threads are provided on the arc-shaped surfaces on both sides for connection with the limit nut (10).
7. The precision turning split fixture according to claim 1, wherein: Multiple groups of the positioning disks (5) are provided, and different positioning disks (5) are used for positioning workpieces with different outer diameters.
8. The precision turning split fixture according to claim 4, wherein: The centers of the spheres of the hemispheres (12) are at the same axis position along the axial direction of the turntable (8).