Clamping tool for machining arc surface of guitar debugging rod
By improving the clamping fixture design and utilizing structures such as balance bars and wedges, the problem of clamping instability caused by vibration during guitar tuning bar machining was solved, achieving high-precision machining of arc surfaces.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-05
- Publication Date
- 2026-03-27
AI Technical Summary
Existing guitar tuning bar clamping fixtures are prone to vibration during processing, causing the surface contact between the clamping block and the tuning bar to become a line contact, resulting in a decrease in processing accuracy.
The clamping fixture design includes a base, two clamping blocks, and a balance bar. The two clamping blocks are locked by locking components, and the balance bar supports the clamping blocks to ensure clamping stability. The combination structure of wedges, push rods, sliders, and elastic elements adapts to changes in the thickness of the adjustment rod, achieving surface contact clamping.
This improves the machining precision of the guitar tuning bar's curved surface, preventing the tuning bar from shifting during machining and enhancing machining stability and accuracy.
Smart Images
Figure CN121733285A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of rod clamping fixture technology, and in particular to a clamping fixture for machining the arc surface of a guitar tuning rod. Background Technology
[0002] When guitar strings are constantly taut, they exert tremendous tension on the neck, causing it to bend forward. The tuning bar, also known as the neck adjuster or tuning peg, is embedded inside the guitar's wooden neck. Its core function is to counteract the tension of the strings; it's a mechanical device used to adjust the curvature of the neck. The lower section of the tuning bar is cylindrical, while the upper section has an arc-shaped surface. The diameter of this arc-shaped surface is larger than that of the cylindrical lower section, causing the axis of the arc-shaped surface to be misaligned with the axis of the cylindrical lower section, creating an eccentric structure. By rotating the lower section, the arc-shaped surface rotates synchronously, allowing for fine-tuning of the string action (the height between the strings and the fretboard) to optimize playability and intonation.
[0003] To process the adjustment rod, a cylindrical rod must first be prepared. Two parallel annular grooves are carved into the lower section. Then, four planes are cut out on the side of the upper section to make the upper section into a square column. The upper and lower sections are connected by a sloping wall. Finally, one of the planes of the upper section is machined into an arc surface.
[0004] When machining the arc surface of the upper section of the guitar tuning bar, a clamping fixture is needed to fix the tuning bar and install the clamping fixture on a lathe. By rotating the clamping fixture, the tuning bar rotates synchronously, and a cutting tool is used to machine one side of the upper section of the tuning bar into an arc surface. The axis of the arc surface coincides with the rotation center of the clamping fixture, but the diameter of the arc surface is larger than the diameter of the lower section of the tuning bar.
[0005] The previous clamping fixture consisted of two clamping blocks that held two side surfaces of the adjustment rod, leaving the other side surface of the adjustment rod exposed above the two clamping blocks. Bolts were passed through the two clamping blocks and tightened to lock the adjustment rod in place, and the exposed surface was machined into an arc shape. This single-sided clamping method is prone to misalignment during machining due to vibration, which can cause the clamping blocks and the adjustment rod to lose their surface contact and instead become line contact. Furthermore, the adjustment rod is susceptible to displacement due to vibration during machining, reducing machining accuracy. Summary of the Invention
[0006] Given that previous clamping fixtures used a single-sided clamping method, the clamping block and the adjusting rod were prone to not maintaining good surface contact due to vibration during the machining process, and instead became line contact. As a result, the position of the adjusting rod was easily offset due to vibration during the machining process, which reduced the machining accuracy. This application proposes an improved clamping fixture to improve machining accuracy.
[0007] A clamping fixture for machining the arc surface of a guitar tuning bar includes a base, two clamping blocks, and a balance bar.
[0008] The base has a communicating cavity and a side cavity. Two vertical clamping blocks are fixed above the base. Between the two clamping blocks are a longitudinally connected balancing cavity, an intermediate cavity, and a product cavity.
[0009] The outer end face of the product cavity, away from the intermediate cavity, is open. Horizontally, the side cavity is located outside the product cavity, and its radial dimension is larger than that of the product cavity. This allows the thicker lower section of the adjustment rod to be vertically inserted into the side cavity and then laterally moved into the receiving cavity, while the thinner upper section of the adjustment rod is embedded in the product cavity and abuts against its bottom wall, with the surface to be processed of the thinner upper section exposed outside the product cavity. Each clamping block has a locking hole for installing a locking element, and the line connecting two opposing locking holes passes through the intermediate cavity. The vertical balance rod is installed in the balance cavity, such that after locking the two clamping blocks, the two side walls of the balance cavity clamp the balance rod, and the two side walls of the product cavity clamp the two side planes of the adjustment rod.
[0010] By adopting the above technical solution, after locking the two clamping blocks with locking components, the two clamping blocks clamp the adjustment rod and balance rod at both ends. The balance rod supports the clamping blocks, thus solving the problem of unstable clamping caused by the two clamping blocks only clamping the adjustment rod.
[0011] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning bar is as follows: the locking hole includes a straight hole and an enlarged hole; the inner end of the straight hole communicates with the intermediate cavity; the straight holes of the two clamping blocks are aligned. The enlarged hole communicates with the outer end of the straight hole, and the radial dimension of the enlarged hole is larger than that of the straight hole. The clamping fixture includes a locking element. The locking element includes a bolt and a nut. The bolt shank can pass through the two opposing straight holes, the bolt head can be embedded in the enlarged hole of one clamping block, and the nut can be embedded in the enlarged hole of the other clamping block and connected to the bolt shank.
[0012] By adopting the above technical solution, two clamping blocks are clamped with bolts. The two clamping blocks clamp the adjustment rod and the balance rod through deformation. The bolts and nuts are small in size and can easily rotate synchronously with the clamping blocks. Furthermore, the heads of the bolts and nuts are embedded in the lock holes, so they will not touch the grinding tools and will not interfere with the grinding process.
[0013] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning bar is that both the balance cavity and the product cavity are square, and the two sides of the balance bar are parallel planes. The two sides of the product cavity are also parallel planes.
[0014] By adopting the above technical solution, the clamping fixture has a simple structure. The balance bar and the adjustment bar are clamped in a balanced manner by two clamping blocks. The structure is solid, and the adjustment bar is not easy to deviate during the processing.
[0015] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning bar is that the balance cavity has symmetrical inclined walls on both sides, the distance between these two inclined walls being smaller at the end closer to the central cavity than at the end farther from the central cavity. The product cavity has two parallel planes on both sides. The clamping fixture also includes a wedge, a push rod, a slider, a limiting mechanism, and an elastic element. The wedge is fixed to the inner wall of one of the clamping blocks. The wedge has an inclined groove parallel to the inclined wall on the same side. One end of the transverse push rod is fixed to the balance bar, and the other end is fixed to the slider, which is embedded in the inclined groove. The limiting mechanism connects the push rod and the clamping block, preventing the push rod from moving radially. The elastic element is installed on the side of the balance bar away from the push rod and supported on the clamping block. Driving the two clamping blocks to move relative to each other enables the inclined groove to move relative to the slider. Together with the elastic element, the push rod is driven to move axially, causing the balance rod to slide along the inclined walls on both sides of the balance cavity. During this process, the slider cannot disengage from the inclined groove, the elastic element always has a rebound force, and the two sides of the balance rod always abut against the inclined walls on both sides of the balance cavity.
[0016] By adopting the above technical solution, since the thickness of the adjustment rod has tolerances and different adjustment rods have slight differences in thickness, while the thickness of the balance rod is fixed, in order to ensure that both ends of the two clamping blocks clamp the adjustment rod and the balance rod, and that the two clamping blocks and the adjustment rod are in surface contact, it is necessary to adapt and adjust the clamping mechanism of the clamping blocks and the balance rod. That is, the balance cavity designed in this solution has symmetrical inclined walls on both sides, as well as a connection structure of wedges, push rods, sliders, limiting mechanisms and elastic elements, so that the balance rod end can adapt to the thickness change of the adjustment rod for adaptive support. Specifically, the two clamping blocks move relative to each other to adapt to clamp the adjustment rod of the current thickness. The relatively moving clamping blocks synchronously drive the balance rod to abut against the two clamping blocks in real time, realizing the support function of the balance rod adapting to the thickness change of the adjustment rod. This allows the two clamping blocks and the adjustment rods of different thicknesses to achieve surface contact clamping, improving structural stability and improving machining accuracy.
[0017] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning peg is that the limiting mechanism includes a bushing and two connecting rods of equal length. The bushing fits snugly over the push rod. Two connecting rods are symmetrically mounted on both sides of the bushing. One end of each connecting rod is hinged to the bushing, and the other end is hinged to a clamping block. The two connecting rods, the push rod, and the inclined groove are located on the same plane.
[0018] By adopting the above technical solution, the two connecting rods can rotate with the two relatively moving clamping blocks, and the bushings limit the push rod, so that the push rod can only move axially and not radially. With the same angle of the inclined groove and inclined wall, the relative movement of the two clamping blocks causes their spacing to change to adapt to the adjustment rods of different thicknesses. At the same time, the two sides of the balance bar always abut against the two inclined wall surfaces, providing support for the adjustment rod at the other end. This ensures that the two clamping blocks and the adjustment rods of different thicknesses maintain surface contact, improving the clamping firmness, preventing the adjustment rod from shifting during the processing, and improving the processing accuracy.
[0019] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning bar is that the two sides of the balance bar are symmetrical inclined surfaces. Driving the two clamping blocks to move relative to each other ensures that the two inclined surfaces always remain in contact with the two inclined walls.
[0020] By adopting the above technical solution, the inclined side and inclined wall of the balance bar are always in contact, which supports the adjustment bar at the other end, so that the two clamps and the adjustment bars of different thicknesses are in surface contact.
[0021] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning bar is that the two sides of the balance bar are symmetrical curved cylindrical surfaces. A tuning bar within a tolerance thickness range is placed inside the product cavity, and the two clamping blocks are driven to move relative to each other, causing the two side walls of the product cavity to be tightly against the two flat surfaces of the thin upper section of the tuning bar. After the two clamping blocks are locked, the curved cylindrical surfaces on both sides of the balance bar are always in line contact with the two inclined wall surfaces.
[0022] By adopting the above technical solution, the balance bar can adapt to the situation where the two sides of the adjustment bar are not parallel, so that the two clamping blocks always maintain surface contact with the two sides of the adjustment bar, improving clamping stability and thus improving machining accuracy.
[0023] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning bar is that the cross-section of the balancing cavity is an isosceles trapezoid, with the narrow end connected to the intermediate cavity. The surfaces of the balance bar facing both the wide and narrow ends of the balancing cavity are planar, and the elastic element is installed between a planar surface of the balance bar and the wall surface of the wide end of the balancing cavity.
[0024] By adopting the above technical solution, the radial dimensions of the balance cavity and balance bar can be made smaller, so that the clamping block can be small in volume and easy to deform and lock, and the structure makes the extension and contraction movement of the elastic element more stable.
[0025] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning bar is that the wedge and the balance bar are located on both sides of the locking hole.
[0026] By adopting the above technical solution, after the locking element passes through the lock hole to lock the two clamping blocks, the push rod is inserted into the inclined groove of the wedge block through the connected slider and is pulled by the wedge block, which helps to increase the degree to which the two sides of the balance rod press against the inclined wall, and provides strong support for the adjustment rod.
[0027] A preferred embodiment of the clamping fixture for machining the arc surface of a guitar tuning peg is that each clamping block has an expansion groove communicating with the side of the intermediate cavity. The expansion groove and the locking hole are located in different layers of the clamping blocks. A portion of the wedge is fixed in the expansion groove and extends into the intermediate cavity.
[0028] By adopting the above technical solution, the expansion groove is set to facilitate the installation of the wedge block, and the wedge block does not interfere with the locking component.
[0029] In summary, the clamping fixture for machining the arc surface of a guitar tuning bar provided in this application has the following beneficial effects: by setting a balance bar at the other end of the tuning bar and locking two clamping blocks in the middle with a locking device, the two ends are clamped in a balanced manner, the structure of the two clamping blocks clamping the tuning bar is stable, the tuning bar is not easy to shift position during the machining process, and the machining accuracy is improved. Attached Figure Description
[0030] Figure 1 This is a three-dimensional structural diagram of a clamping fixture for machining the arc surface of a guitar tuning bar, as described in Embodiment 1, with the tuning bar installed.
[0031] Figure 2 for Figure 1 Another structural view showing the locking mechanism, balance bar, and adjustment bar hidden.
[0032] Figure 3 for Figure 2 A second-person perspective view.
[0033] Figure 4 for Figure 1 The structural diagram is hidden behind the base and clamping blocks.
[0034] Figure 5 for Figure 2 A third-person perspective view.
[0035] Figure 6 This is a three-dimensional structural diagram of the clamping fixture used for machining the arc surface of a guitar tuning bar in Embodiment 2, with the tuning bar installed.
[0036] Figure 7 for Figure 6 Top-view structural diagram.
[0037] Figure 8 for Figure 6 A 3D image hidden behind a clip.
[0038] Figure 9 for Figure 8 A second-person perspective view.
[0039] Figure 10 for Figure 9 Enlarged view of region A.
[0040] Figure 11 exhibit Figure 7 Partial structure, with dashed lines simulating individual components after movement, and additional dashed lines used as auxiliary markers.
[0041] Figure 12 The top view structural diagram shows the clamping fixture used for machining the arc surface of the guitar tuning bar in Embodiment 3, with the tuning bar mounted on it.
[0042] Reference numerals: 1. Base; 2. Clamping block; 3. Balance bar; 101. Cavity; 102. Side cavity; 201. Balance cavity; 202. Intermediate cavity; 203. Product cavity; 4. Adjustment rod; 41. Upper section; 42. Lower section; 204. Locking hole; 2041. Straight hole; 2042. Expanded hole; 5. Locking element; 51. Bolt; 52. Nut; 411. Arc surface; 2043. Inclined wall surface; 301. Curved cylindrical surface; 6. Wedge block; 7. Push rod; 8. Slider; 9. Limiting mechanism; 10. Elastic element; 2044. Expanding groove; 601. Inclined groove; 91. Bushing; 92. Connecting rod; 302. Inclined plane. Detailed Implementation
[0043] The technical solutions in the embodiments are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the following embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Example 1
[0044] refer to Figure 1 A clamping fixture for machining the arc surface of a guitar tuning bar includes a base 1, two clamping blocks 2 and a balance bar 3.
[0045] refer to Figure 2 The base 1 is integrally formed by coaxially connecting several circular blocks and cylinders, and is installed in a lathe, where it can be driven to rotate at high speed. The base 1 has an upward-opening cavity, which is divided into a communicating cavity 101 and a side cavity 102.
[0046] refer to Figure 3 Two semi-cylindrical clamping blocks 2 are symmetrically welded onto the base 1, giving way to the side cavity 102. Between the two clamping blocks 2, a longitudinally connected balance cavity 201, intermediate cavity 202, and product cavity 203 are formed. The product cavity 203 is connected downward to the receiving cavity 101.
[0047] The balancing cavity 201 is square-column shaped, and the balancing rod 3 is square-column shaped, with the balancing rod 3 inserted into the balancing cavity 201. The intermediate cavity 202 is a narrow square. The product cavity 203 is square-column shaped, with its outer end face open. The widths of both the balancing cavity 201 and the product cavity 203 are greater than those of the intermediate cavity 202.
[0048] refer to Figure 4 The product to be clamped by the clamping fixture is the guitar tuning rod 4. The tuning rod 4 is divided into an upper section 41 and a lower section 42. Before processing, the upper section 41 is a square column and the lower section 42 is a cylinder. The upper section 41 and the lower section 42 are coaxial, and the length of any side of the cross section of the upper section 41 is smaller than the diameter of the lower section 42.
[0049] The upward opening size of the side cavity 102 is larger than the diameter of the lower section 42 of the adjustment rod 4. The lower section 42 of the adjustment rod 4 is first inserted into the side cavity 102 and then moved laterally into the cavity 101, so that the upper section 41 of the adjustment rod 4 enters the product cavity 203 and abuts against the bottom wall of the product cavity 203. The outer side of the upper section 41 of the adjustment rod 4 is exposed outside the product cavity 203 and awaits processing.
[0050] refer to Figure 5 Each clamping block 2 has two locking holes 204, one above the other. Each locking hole 204 includes a straight hole 2041 and an enlarged hole 2042. The straight hole 2041 is vertically connected to the intermediate cavity 202, and the enlarged hole 2042 is coaxially connected to the side of the straight hole 2041 that is away from the intermediate cavity 202.
[0051] The clamping fixture for machining the arc surface of the guitar tuning bar can also include two sets of locking components 5, installed in the upper and lower sets of locking holes 204. Each set of locking components 5 includes a bolt 51 and a nut 52. The bolt 51's threaded shaft passes through the two mating straight holes 2041, and the head of the bolt 51 is recessed into an enlarged hole 2042. The other end is connected to the end of the threaded shaft with a nut 52, and both the end of the threaded shaft and the nut 52 are recessed into another enlarged hole 2042. With the balance bar 3 and the tuning bar 4 already installed, installing and locking the locking components 5 can clamp the balance bar 3 and the tuning bar 4 simultaneously. Since neither end of the locking component 5 protrudes from the clamping block 2, the cutting tool on the lathe that abuts against the machining surface of the tuning bar 4 will not touch the locking component 5 during the rotation of the tuning bar 4 with the base. Install the clamping fixture on the lathe, rotate the base at high speed, use the cutting tool to abut against the outer plane of the upper section 41 of the adjustment rod 4 and move the cutting tool up and down, then gradually process the outer plane of the upper section 41 of the adjustment rod 4 into an arc surface 411, and complete the machining.
[0052] The clamping fixture in this embodiment has a simple structure. The balance bar 3 balances the adjustment bar 4, and the two clamping blocks 2 are locked in the middle by the locking piece 5. The clamping of the adjustment bar 4 by the two clamping blocks 2 is stable. During the processing, the position of the adjustment bar 4 is not easy to shift, and the processing accuracy is high. Example 2
[0053] Given that the thickness of the upper section 41 of the adjustment rod 4 has tolerance, while the thickness of the balance rod 3 is fixed, in order to further improve the adaptability of the balance rod 3 to the upper section 41 of the adjustment rod 4 with different thicknesses and to better play the role of balancing the clamping force, this embodiment designs another clamping fixture.
[0054] The base in this embodiment is the same as that in Embodiment 1. The outer side of the clamping block 2 in this embodiment is semi-cylindrical, but the shape of the inner side surfaces of the two clamping blocks 2 facing each other is different from that in Embodiment 1.
[0055] In this embodiment, a longitudinally connected balancing cavity 201, intermediate cavity 202, and product cavity 203 are formed between the two clamping blocks 2. The product cavity 203 is connected downward to the receiving cavity 101.
[0056] refer to Figure 6 The balance cavity 201 has an isosceles trapezoidal cross-section. The narrow end (i.e., the upper base) of the isosceles trapezoid connects to the middle cavity 202, while the wide end (i.e., the lower base) is away from the middle cavity 202. The two sides of the balance cavity 201 are two symmetrical inclined walls 2043.
[0057] The intermediate cavity 202 is a narrow square, and its two ends are connected to the balance cavity 201 and the product cavity 203. The product cavity 203 is square, and the side of the product cavity 203 away from the intermediate cavity 202 is open.
[0058] refer to Figure 7 The two sides of the balance bar 3 are curved cylindrical surfaces 301, which abut against the two inclined wall surfaces 2043 in line contact. The side of the balance bar 3 facing the upper bottom of the balance cavity 201 is a plane, and the side facing the lower bottom of the balance cavity 201 is also a plane.
[0059] refer to Figure 8 The clamping fixture in this embodiment includes a wedge block 6 and three push rods 7, as shown in the reference. Figure 9 and Figure 10 The clamping fixture in this embodiment also includes three sliders 8, three sets of limiting mechanisms 9, and multiple elastic elements 10.
[0060] The clamping block 2 has a recessed expansion groove 2044 in the intermediate cavity 202. Vertically, the expansion groove 2044 is located between the upper and lower sets of lock holes 204. The expansion groove 2044 leads to the intermediate cavity 202. The wedge 6 is fixed to the inner wall of the expansion groove 2044 of the clamping block 2 and extends into the intermediate cavity 202. From a top perspective, the wedge 6 and the balance rod 3 are located on both sides of the lock hole 204. The side of the wedge 6 facing the balance cavity 201 is an inclined surface, and three parallel inclined grooves 601 are formed on this inclined surface. The inclined grooves 601 are parallel to the inclined wall surface 2043 on the same side, which is the inclined wall surface 2043 on the clamping block 2 to which the wedge 6 is connected. One end of each push rod 7 is connected to a slider 8, which is preferably spherical. The slider 8 is embedded in an inclined groove 601 and can slide along the inclined groove 601 but cannot disengage from the inclined groove 601. The other end of the push rod 7 is vertically connected to the balance bar 3. The push rod 7 is preferably cylindrical.
[0061] Each set of limiting mechanisms 9 includes a bushing 91 and two connecting rods 92 of equal length. Each bushing 91 is fitted onto a push rod 7. Two connecting rods 92 are symmetrically hinged to both sides of each bushing 91, and the other end of each connecting rod 92 is hinged to the inner side of the clamping block 2, so that the bushing 91 is located between the two clamping blocks 2. The inner side can be the inner wall of the expansion groove 2044, and the hinge point avoids the wedge block 6.
[0062] The push rod 7, bushing 91, two connecting rods 92, and inclined groove 601, all connected in the same group, are located on the same plane. The elastic element 10 can be a spring, with one end fixed to the side of the balance bar 3 away from the intermediate cavity 202, and the other end fixed to the lower surface of the balance cavity 201, i.e., the inner wall of one clamping block 2. Multiple layers of elastic elements 10 are installed on the balance bar 3. Two elastic elements 10 are installed in each layer, each connected to one of the two clamping blocks 2.
[0063] When processing the adjustment rod 4, after inserting the upper section 41 of the adjustment rod 4 into the product cavity 203, the locking part 5 is locked, so that the inner wall surfaces of the two clamping blocks 2 clamp the two side planes of the upper section 41 of the adjustment rod 4. During this locking process, the two clamping blocks 2 move relative to each other, causing the wedge block 6 to move and pushing the slider 8 to move along the groove of the wedge block 6. At the same time, the two connecting rods 92 of the limiting mechanism 9 change the angle with the bushing 91 as the two clamping blocks 2 move relative to each other. Since the connecting rods 92 on both sides are of equal length and symmetrically connected to the bushing 91, and the two clamping blocks 2 move away from each other or close to each other, the angle between the connecting rods 92 on both sides and the bushing 91 will change equally and always remain consistent. This ensures that the bushing 91 can only move axially and cannot deflect radially. The bushing 91 is always in the middle of the two clamping blocks 2. The bushing 91 restricts the push rod 7 to only move axially and cannot deflect radially. Therefore, under the push of wedge 6, slider 8 and push rod 7 move along the axial direction of push rod 7, which in turn moves balance bar 3. (Reference) Figure 11Let the inclination angle of the inclined groove 601 (the angle between the inclined groove 601 and the docking direction of the two clamping blocks 2) be α, the lateral movement distance (the docking direction of the two clamping blocks 2) be d, and the longitudinal movement distance be h, tanα = h / d. Since the slider 8, push rod 7, and balance rod 3 are fixed to each other and move synchronously, the longitudinal movement distance of the balance rod 3 is also h. Since the wedge 6 and the inclined wall surface 2043 on the same side are on the same clamping block 2, the lateral movement distance of the wedge 6 and the inclined wall surface 2043 are equal, that is, the lateral movement distance of the inclined wall surface 2043 is also d. Since the inclined groove 601 and the inclined wall surface 2043 on the same side are parallel to each other, the inclination angle is also α. Draw a longitudinal line from the point where the inclined wall 2043 before movement originally contacted the balance bar 3 (original contact point P). This longitudinal line intersects the inclined wall 2043' after movement (with an intersection point Q). Since tanα = h / d, the distance from the original contact point P to the intersection point Q is h. Because the original contact point P was in contact with the balance bar 3 before movement, and the balance bar 3 moved longitudinally a distance h but did not move laterally, the intersection point Q becomes the new contact point Q between the inclined wall 2043' and the balance bar 3' after movement. The movement of the inclined wall 2043 and the balance bar 3 on the other side is symmetrical to that on this side, that is, the two clamping blocks 2 move relative to each other. After movement, the two sides of the balance bar 3 always abut against the inclined wall 2043, and the elastic element 10 can push the balance bar 3 to further press against the inclined wall 2043. The slider 8 cannot disengage from the inclined groove 601, meaning the wedge block 6 can drag the balance bar 3 to further press against the inclined wall 2043. These mechanisms work together to ensure that after the clamping fixture locks the adjustment rod 4 of different thicknesses, the balance bar 3 and the two clamping blocks 2 can adapt to the thickness changes of the adjustment rod 4, always providing support for the adjustment rod 4. The two clamping blocks 2 are always in surface contact with the two sides of the adjustment rod 4, resulting in a stable clamping structure. During the machining of the adjustment rod 4, the position of the adjustment rod 4 is not easily shifted, and the machining accuracy is high. This clamping fixture can also adapt to situations where the two sides of the upper section 41 of the adjustment rod 4 are slightly non-parallel. After the clamping fixture locks the adjustment rod 4, the balance bar 3 and the two clamping blocks 2 can adapt to movement, always providing support for the adjustment rod 4. The two clamping blocks 2 are always in surface contact with the two sides of the adjustment rod 4.
[0064] The angle of the inclined groove 601 can be 30°~60°, for example, 45°. The 45° angle is convenient for the wedge block 6 to push the slider 8 to move, and also ensures that the width of the balance cavity 201 is not too wide, so that the radial dimension of the clamping block 2 is not too large, thus making it easy to deform and clamp the adjustment rod 4.
[0065] It should be noted that during the movement of the balance bar 3 along the inclined wall 2043, the elastic element 10 is always in a compressed state. Example 3
[0066] refer to Figure 12The only difference between this embodiment and Embodiment Two is that the shape of the balance bar 3 in this embodiment is different from that in Embodiment Two. In this embodiment, the two sides of the balance bar 3 are inclined planes 302, and the inclination angle of these inclined planes 302 (the angle between the inclined plane 302 and the docking direction of the two clamping blocks 2) is α, which is equal to the inclination angle α of the inclined groove 601 (the angle between the inclined groove 601 and the docking direction of the two clamping blocks 2). Similarly, after clamping and locking the adjustment rods 4 of different thicknesses, the balance bar 3 and the two clamping blocks 2 can adapt to the thickness changes of the adjustment rods 4, always providing support for the adjustment rods 4. The clamping is balanced at both ends, and the clamping structure is stable. During the processing of the adjustment rods 4, the position of the adjustment rods 4 is not easily shifted, resulting in high processing accuracy. The difference is that in Embodiment Two, the two sides of the balance bar 3 and the inclined wall surface 2043 are always in line contact, while in this embodiment, the two sides of the balance bar 3 and the inclined wall surface 2043 are always in surface contact, resulting in better support.
[0067] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A clamping fixture for machining the arc surface of a guitar tuning peg, characterized in that, It includes a base (1), two clamps (2) and a balance bar (3); The base (1) has a connected cavity (101) and a side cavity (102); two vertical clamping blocks (2) are fixed above the base (1); between the two clamping blocks (2) there is a longitudinally connected balancing cavity (201), an intermediate cavity (202) and a product cavity (203). The outer end face of the product cavity (203) is open away from the intermediate cavity (202); in the horizontal direction, the side cavity (102) is located outside the product cavity (203), and the radial dimension of the side cavity (102) is larger than that of the product cavity (203), so that the thicker lower section (42) of the adjustment rod (4) can be vertically inserted into the side cavity (102) and then laterally moved into the cavity (101), while the thinner upper section (41) of the adjustment rod (4) is embedded in the product cavity (203) and abuts against the bottom wall of the product cavity (203). The surface to be processed of segment (41) is exposed outside the product cavity (203); each clamping block (2) is provided with a locking hole (204) for installing a locking member (5), and the line connecting two opposing locking holes (204) passes through the intermediate cavity (202); the vertical balance rod (3) is installed in the balance cavity (201), so that after the two clamping blocks (2) are locked, the two side walls of the balance cavity (201) clamp the balance rod (3), and the two side walls of the product cavity (203) clamp the two side planes of the adjustment rod (4).
2. The clamping fixture for machining the arc surface of a guitar tuning peg according to claim 1, characterized in that, The locking hole (204) includes a straight hole (2041) and an enlarged hole (2042). The inner end of the straight hole (2041) is connected to the intermediate cavity (202). The straight holes (2041) of the two clamping blocks (2) are opposite each other. The enlarged hole (2042) is connected to the outer end of the straight hole (2041). The radial dimension of the enlarged hole (2042) is larger than that of the straight hole (2041). The clamping fixture includes a locking element (5). The locking element (5) includes a bolt (51) and a nut (52). The bolt (51) can pass through the two opposite straight holes (2041). The head of the bolt (51) can be embedded in the enlarged hole (2042) of one of the clamping blocks (2). The nut (52) can be embedded in the enlarged hole (2042) of the other clamping block (2) and connected to the bolt.
3. The clamping fixture for machining the arc surface of a guitar tuning bar according to claim 1 or 2, characterized in that, Both the balance cavity (201) and the product cavity (203) are square, and the two sides of the balance rod (3) are parallel planes; the two sides of the product cavity (203) are parallel planes.
4. The clamping fixture for machining the arc surface of a guitar tuning bar according to claim 1 or 2, characterized in that, The balancing cavity (201) has symmetrical inclined walls (2043) on both sides. The distance between these two inclined walls (2043) is smaller at the end closer to the intermediate cavity (202) than at the end farther from the intermediate cavity (202). The product cavity (203) has two parallel planes on both sides. The clamping fixture further includes a wedge (6), a push rod (7), a slider (8), a limiting mechanism (9), and an elastic element (10); the wedge (6) is fixed to the inner wall of one of the clamping blocks (2); the wedge (6) has a groove (601) parallel to the inclined wall surface (2043) on the same side; one end of the transverse push rod (7) is fixed to the balance bar (3), and the other end is fixed to the slider (8), the slider (8) being embedded in the groove (601); the limiting mechanism (9) connects the push rod (7) and the clamping block (2), preventing the push rod (7) from moving radially; the elastic element (10) is installed on the side of the balance bar (3) away from the push rod (7) and supported on the clamping block (2); Driving the two clamping blocks (2) to move relative to each other enables the inclined groove (601) to move relative to the slider (8), and together with the elastic element (10), drives the push rod (7) to move axially, causing the balance rod (3) to slide along the inclined wall surface (2043) on both sides of the balance cavity (201). During this process, the slider (8) cannot disengage from the inclined groove (601), the elastic element (10) always has a rebound force, and the two sides of the balance rod (3) always abut against the inclined wall surface (2043) on both sides of the balance cavity (201).
5. The clamping fixture for machining the arc surface of a guitar tuning peg according to claim 4, characterized in that, The limiting mechanism (9) includes a bushing (91) and two connecting rods (92) of equal length; the bushing (91) fits snugly over the push rod (7); the two connecting rods (92) are symmetrically installed on both sides of the bushing (91); one end of each connecting rod (92) is hinged to the bushing (91), and the other end is hinged to a clamping block (2); the two connecting rods (92), the push rod (7), and the inclined groove (601) are located on the same plane.
6. The clamping fixture for machining the arc surface of a guitar tuning peg according to claim 4, characterized in that, The balance bar (3) has symmetrical inclined sides on both sides; it drives the two clamping blocks (2) to move relative to each other, and the two inclined sides always fit against the two inclined walls (2043).
7. The clamping fixture for machining the arc surface of a guitar tuning bar according to claim 4, characterized in that, The balance bar (3) has symmetrical curved cylindrical surfaces (301) on both sides; an adjustment rod (4) with a tolerance thickness is placed in the product cavity (203) to drive the two clamping blocks (2) to move relative to each other, so that the two side walls of the product cavity (203) are in close contact with the two side planes of the thin upper section (41) of the adjustment rod (4). After the two clamping blocks (2) are locked, the curved cylindrical surfaces (301) on both sides of the balance bar (3) are always in line contact with the two inclined wall surfaces (2043).
8. The clamping fixture for machining the arc surface of a guitar tuning bar according to claim 7, characterized in that, The cross-section of the balancing cavity (201) is an isosceles trapezoid, with the narrow end connected to the intermediate cavity (202). The surfaces of the balance bar (3) facing the wide end and the narrow end of the balance cavity (201) are both planes, and the elastic element (10) is installed between a plane of the balance bar (3) and the wall surface of the wide end of the balance cavity (201).
9. The clamping fixture for machining the arc surface of a guitar tuning peg according to claim 4, characterized in that, The wedge (6) and the balance bar (3) are located on both sides of the lock hole (204).
10. The clamping fixture for machining the arc surface of a guitar tuning peg according to claim 4, characterized in that, Each of the clamping blocks (2) is provided with an expansion groove (2044) which is connected to the side of the intermediate cavity (202); the expansion groove (2044) and the locking hole (204) are located in different layers of the clamping blocks (2); a portion of the wedge (6) is fixed in the expansion groove (2044) and extends into the intermediate cavity (202).