A turning fixture for ensuring the positional accuracy of gun drill holes

Abstract

This invention discloses a turning fixture for ensuring the positional accuracy of gun drill holes, belonging to the field of machine tool fixtures. The turning fixture includes an eccentric drill jig and a workpiece. An eccentric hole and several pin holes are formed on the end face of the workpiece. A positioning mandrel is disposed near the end face within the eccentric hole. The positioning mandrel matches the eccentric drill jig. A circular hole is formed on the side wall of the eccentric drill jig, coaxial with the workpiece. A cavity is formed inside the positioning mandrel, and a fixing mechanism is disposed within the cavity. A connecting assembly is provided between the eccentric drill jig and the end face of the workpiece. This fixture allows the positioning mandrel to be placed and fixed within the workpiece cavity, while simultaneously cooperating with the eccentric drill jig for positioning, ensuring both accuracy and improved machining efficiency.

Description

Technical Field

[0001] This invention relates to the field of machine tool fixtures, and more specifically, to a turning fixture for ensuring the positional accuracy of gun drill holes. Background Technology

[0002] Currently, eccentric mandrel tools are widely used in oil well completion tools. The eccentricity between the central outer circle and the eccentric outer circle of the workpiece varies from 11mm to 50mm, and this series of workpieces has 5 to 8 gun drill through holes with a length of 1500mm to 2000mm.

[0003] Because machining small-diameter gun drill holes ΦC and main deep holes ΦB is prone to misalignment and is difficult, the process often involves machining the gun drill holes ΦC and main deep holes ΦB first without finishing turning the outer diameter datum, and then finishing turning the outer diameter. However, this may cause the positional accuracy of the gun drill holes to exceed the tolerance after finishing turning the outer diameter. Therefore, when finishing turning the outer diameter, it is necessary to take into account the positional accuracy of all small-diameter gun drill holes ΦC and main deep holes ΦB. In other words, it is necessary to find the common axis of the small-diameter gun drill holes ΦC and main deep holes ΦB before finishing turning the outer diameter to ensure the positional accuracy of all gun drill holes and main deep holes.

[0004] Gun drilling requires positioning based on the inner hole and determining the position of the gun drill hole. During the machining process, straightening and correction are necessary, which will cause changes in the positional accuracy between the gun drill hole and the outer circle. Therefore, when finishing the outer circle, the gun drill hole must be used as the reference for positioning.

[0005] Existing eccentric plugs cannot be positioned using gun drilling, failing to meet the positional accuracy requirements of the gun drill hole, inner hole, and outer circle. During the cutting process, the workpiece is subjected to centrifugal force during rotation, which may cause accuracy deviations. Moreover, since eccentric machining is used, traditional positioning generally involves using the machine tool tailstock to directly press against the workpiece for support and positioning. Although this achieves a positioning effect, the workpiece will experience certain accuracy deviations due to the depth of cut and material properties during machining, affecting the workpiece quality. Summary of the Invention

[0006] 1. Technical problems to be solved

[0007] In view of the problems existing in the prior art, the purpose of this invention is to provide a turning fixture for ensuring the positional accuracy of gun drill holes. It can fix the positioning mandrel in the inner cavity of the workpiece and use it in conjunction with the eccentric drill jig for positioning, which not only ensures accuracy but also improves processing efficiency.

[0008] 2. Technical Solution

[0009] To solve the above problems, the present invention adopts the following technical solution.

[0010] A turning fixture for ensuring the positional accuracy of a gun drill hole includes an eccentric drill jig and a workpiece. The workpiece has an eccentric hole and a plurality of pin holes on its end face. A positioning mandrel is provided near the end face of the eccentric hole. The positioning mandrel matches the eccentric drill jig. A circular hole is provided on the side wall of the eccentric drill jig. The circular hole is coaxial with the workpiece. A cavity is provided inside the positioning mandrel. A fixing mechanism is provided in the cavity. A connecting assembly is provided between the eccentric drill jig and the end face of the workpiece.

[0011] Furthermore, the fixing mechanism includes a first bevel gear located within the cavity. A round rod is fixedly connected to the side wall of the first bevel gear, and the other end of the round rod passes through the positioning mandrel and is fixedly connected to an internal hexagonal locking block. The round rod is movably connected to the positioning mandrel. Four second bevel gears are evenly meshed on the right side of the first bevel gear. Each of the second bevel gears is rotatably connected to the side wall of the cavity. Each of the second bevel gears has a screw hole on its side wall, and a screw is movably connected to each screw hole. The end of the screw away from the first bevel gear passes through the positioning mandrel and is rotatably connected to an arc-shaped top plate. The screw is rotatably connected to the positioning mandrel.

[0012] Furthermore, two positioning rods are symmetrically fixedly connected to the side wall of the arc-shaped top plate near the positioning mandrel, and several positioning holes are opened on the side wall of the positioning mandrel, with the positioning rods being movably connected to the positioning holes.

[0013] Furthermore, the connecting assembly includes a locking bolt, which is movably connected to the side wall of the eccentric drill jig. The side wall of the pin hole is provided with an internal thread near the end face, and the locking bolt matches the internal thread.

[0014] Furthermore, bearings are fixedly connected to the sidewalls of the second bevel gear on the side away from the center of the first bevel gear, and the sidewalls of the bearings on the side away from the second bevel gear are rotatably connected to the cavity sidewalls.

[0015] Furthermore, rubber pads are fixedly connected to the sidewalls of the arc-shaped top plate away from the positioning mandrel, and the rubber pads are arranged in an arc shape.

[0016] Furthermore, the positioning mandrel is stepped, and a circular groove is formed on the end face of the positioning mandrel, with the internal hexagonal locking block located inside the circular groove.

[0017] Furthermore, the diameter of the left end face of the eccentric drill jig is smaller than the diameter of the right end face, and the circular hole is opened on the left end face of the eccentric drill jig.

[0018] 3. Beneficial effects

[0019] Compared with the prior art, the advantages of this invention are:

[0020] (1) This technical solution uses the mutual cooperation between the eccentric drilling jig, the positioning mandrel, the locking bolt and the workpiece to fix the positioning mandrel in the reference inner hole, and uses the locking bolt to connect and position it with the pin hole. Then, the machine tool tailstock tip abuts against the round hole to process the outer circle of the eccentricity. After processing, the eccentric drilling jig and the positioning mandrel can be removed, which not only ensures the accuracy but also improves the processing efficiency.

[0021] (2) This technical solution uses the mutual cooperation between the eccentric drilling jig, the positioning mandrel and the workpiece to use the outer circle as the reference for the gun drill hole when machining the gun drill hole, and the gun drill hole as the reference for the finish machining of the outer circle when finishing the outer circle. In this way, the gun drill hole is used as the reference for the finish machining of the outer circle. The positional accuracy of the gun drill hole after finish machining is guaranteed by using the end face pin hole as the reference for machining the outer circle. Because there is an eccentric distance between the gun drill hole and the outer circle, the common axis formed by the six gun drill holes is required as the axis for finish machining of the outer circle. Therefore, a special left-end finish machining positioning fixture is designed.

[0022] (3) This technical solution achieves the mutual cooperation between the positioning mandrel, the workpiece and the fixing mechanism. When the positioning mandrel is placed in the inner cavity of the workpiece, the hexagonal locking block can be rotated to expand the outer arc-shaped top plate and press against the side wall of the eccentric hole. The arc-shaped top plate is coaxial with the positioning mandrel, which increases the stability of the positioning mandrel and avoids the phenomenon of the positioning mandrel shaking when the workpiece is rotated, thereby ensuring the cutting accuracy of the workpiece. Attached Figure Description

[0023] Figure 1 This is a perspective view of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the workpiece structure in this invention;

[0026] Figure 4 This is a schematic diagram of the left oblique view of the positioning mandrel in this invention;

[0027] Figure 5 This is a right oblique view of the positioning mandrel structure in this invention;

[0028] Figure 6 For the present invention Figure 5 A in the enlarged view.

[0029] Description of the numbers in the figure:

[0030] 1. Eccentric drill jig; 2. Positioning mandrel; 3. Workpiece; 4. Eccentric hole; 5. Pin hole; 6. Internal thread; 7. Locking bolt; 8. Round hole; 9. Cavity; 10. First bevel gear; 11. Round rod; 12. Hexagonal locking block; 13. Second bevel gear; 14. Screw hole; 15. Screw; 16. Arc-shaped top plate; 17. Positioning rod; 18. Positioning hole; 19. Bearing; 20. Rubber pad; 21. Round groove. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] Example 1:

[0033] Please see Figure 1-6 A turning fixture for ensuring the positional accuracy of a gun drill hole includes an eccentric drill jig 1 and a workpiece 3. An eccentric hole 4 is provided on the end face of the workpiece 3, and several pin holes 5 are provided on the end face of the workpiece 3. A positioning mandrel 2 is provided in the inner cavity of the eccentric hole 4 near the end face. The positioning mandrel 2 is matched with the eccentric drill jig 1. A circular hole 8 is provided on the side wall of the eccentric drill jig 1. The circular hole 8 is coaxial with the workpiece 3. The diameter of the left end face of the eccentric drill jig 1 is smaller than the diameter of the right end face. The circular hole 8 is provided on the left end face of the eccentric drill jig 1, which facilitates the tip of the machine tool tailstock to abut into the circular hole 8 for positioning. At the same time, the corners of the circular hole 8 are chamfered. A cavity 9 is provided inside the positioning mandrel 2. A fixing mechanism is provided in the cavity 9. A connecting component is provided between the end faces of the eccentric drill jig 1 and the workpiece 3.

[0034] By cooperating with the eccentric drill jig 1, the positioning mandrel 2, the locking bolt 7, and the workpiece 3, the positioning mandrel 2 is inserted into the eccentric hole 4 and fixed. The locking bolt 7 is connected to the pin hole 5 for positioning. Then, the tip of the machine tool tailstock abuts against the round hole 8, thereby machining the outer circle of the eccentricity. After machining, the eccentric drill jig 1 and the positioning mandrel 2 can be removed, which ensures both accuracy and improves machining efficiency.

[0035] See Figure 4 and Figure 5The fixing mechanism includes a first bevel gear 10, which is located inside the cavity 9. A round rod 11 is fixedly connected to the side wall of the first bevel gear 10. The other end of the round rod 11 passes through the positioning mandrel 2 and is fixedly connected to an internal hexagon locking block 12. The positioning mandrel 2 is stepped, and a round groove 21 is opened on the end face of the positioning mandrel 2. The internal hexagon locking block 12 is located inside the round groove 21, which can store the internal hexagon locking block 12 and facilitate the eccentric drilling jig. 1. The round rod 11 is movably connected to the positioning mandrel 2. Four second bevel gears 13 are evenly meshed on the right side of the first bevel gear 10. The second bevel gears 13 are rotatably connected to the side wall of the cavity 9. Each second bevel gear 13 has a screw hole 14 on its side wall. Each screw hole 14 is movably connected to a screw rod 15. The end of the screw rod 15 away from the first bevel gear 10 passes through the positioning mandrel 2 and is rotatably connected to an arc-shaped top plate 16. The screw rod 15 is rotatably connected to the positioning mandrel 2.

[0036] Through the cooperation between the positioning mandrel 2, the workpiece 3, and the fixing mechanism, when the positioning mandrel 2 is placed in the inner cavity of the workpiece 3, the rotatable internal hexagonal locking block 12 causes the outer arc-shaped top plate 16 to expand and press against the side wall of the eccentric hole 4. The arc-shaped top plate 16 is coaxial with the positioning mandrel 2, which increases the stability of the positioning mandrel 2 and avoids the phenomenon of the positioning mandrel 2 shaking when the workpiece 3 rotates, thereby ensuring the cutting accuracy of the workpiece 3.

[0037] See Figure 5 and Figure 6 Two positioning rods 17 are symmetrically fixedly connected to the side wall of the arc-shaped top plate 16 near the positioning mandrel 2. Several positioning holes 18 are opened on the side wall of the positioning mandrel 2, and the positioning rods 17 are movably connected to the positioning holes 18.

[0038] Through the mutual cooperation between the eccentric drill jig 1, the positioning mandrel 2, and the workpiece 3, the outer circle is used as the reference for the gun drill hole when machining it. When finishing the outer circle, the gun drill hole is used as the reference for the finishing of the outer circle. In this way, the gun drill hole is used as the reference for the finishing of the outer circle. The positional accuracy of the gun drill hole is guaranteed by using the end face pin hole 5 as the reference for machining the outer circle. The positional accuracy of the gun drill hole is guaranteed by using the outer circle as the reference. Because there is an eccentric distance between the gun drill hole and the outer circle, the common axis formed by the six gun drill holes is required as the axis for finishing of the outer circle. For this purpose, a special left-end finishing positioning fixture is designed.

[0039] See Figure 1 and Figure 2 The connecting assembly includes a locking bolt 7. The locking bolt 7 is movably connected to the side wall of the eccentric drill jig 1. The pin hole 5 has an internal thread 6 near the end face. The locking bolt 7 and the internal thread 6 are matched with each other. By setting the connecting assembly, the eccentric drill jig 1 can be easily fixed to the end face of the workpiece 3.

[0040] See Figure 4 and Figure 5Bearings 19 are fixedly connected to the side wall of the second bevel gear 13 away from the center of the first bevel gear 10. The side wall of the bearings 19 away from the second bevel gear 13 is rotatably connected to the side wall of the cavity 9. The bearings 19 are connected to the second bevel gear 13, which does not affect the transmission of the second bevel gear 13, and also serves as a limit support. The screw 15 passes through the inner ring of the bearing 19. The inner diameter of the inner ring of the bearing 19 is larger than the outer diameter of the screw 15, and the inner ring of the bearing 19 does not contact the screw 15.

[0041] See Figure 4 and Figure 5 Rubber pads 20 are fixedly connected to the side wall of the arc-shaped top plate 16 away from the positioning spindle 2. The rubber pads 20 are arc-shaped. By setting the rubber pads 20, the friction between the arc-shaped top plate 16 and the side wall of the eccentric hole 4 can be increased, and the arc-shaped top plate 16 can be prevented from directly contacting the inner diameter of the workpiece 3, thus avoiding scratches that affect the roughness and quality of the workpiece 3.

[0042] In use: When cutting workpiece 3, to ensure its accuracy, first place the positioning mandrel 2 in the designated position inside the eccentric hole 4 of workpiece 3. Then, rotate the internal hexagon locking block 12 through a wrench or other components. The internal hexagon locking block 12 drives the first bevel gear 10 to rotate through the round rod 11. The first bevel gear 10 meshes with the second bevel gear 13 to rotate. The second bevel gear 13 drives the screw 15 to move outward through the screw hole 14, so that the arc-shaped top plate 16 presses against the side wall of the eccentric hole 4, preventing the positioning mandrel 2 from rolling during the processing of workpiece 3. Then, place the eccentric drill jig 1 against the end face of workpiece 3 and fix it with the locking bolt 7. After that, clamp workpiece 3 on the machine tool and use the tip of the machine tool tailstock to press against the round hole 8 on the eccentric drill jig 1 to complete the positioning and clamping. After processing, simply remove the eccentric drill jig 1 and the positioning mandrel 2. This ensures both accuracy and improves processing efficiency.

[0043] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A turning fixture for ensuring the positional accuracy of a gun drill hole, comprising an eccentric drill jig (1) and a workpiece (3), characterized in that: The workpiece (3) has an eccentric hole (4) on its end face and several pin holes (5) on its end face. A positioning mandrel (2) is provided in the inner cavity of the eccentric hole (4) near the end face. The positioning mandrel (2) matches the eccentric drill jig (1). A circular hole (8) is provided on the side wall of the eccentric drill jig (1). The circular hole (8) is coaxial with the workpiece (3). A cavity (9) is provided inside the positioning mandrel (2). A fixing mechanism is provided in the cavity (9). A connecting component is provided between the eccentric drill jig (1) and the end face of the workpiece (3). The fixing mechanism includes a first bevel gear (10), which is located inside the cavity (9). A round rod (11) is fixedly connected to the side wall of the first bevel gear (10). The other end of the round rod (11) passes through the positioning mandrel (2) and is fixedly connected to an internal hexagonal locking block (12). The round rod (11) is movably connected to the positioning mandrel (2). Four second bevel gears (13) are evenly meshed on the right side of the first bevel gear (10). The second bevel gears (13) are all rotatably connected to the side wall of the cavity (9). Each of the second bevel gears (13) has a screw hole (14) on its side wall. A screw rod (15) is movably connected in each screw hole (14). The end of the screw rod (15) away from the first bevel gear (10) passes through the positioning mandrel (2) and is rotatably connected to an arc-shaped top plate (16). The screw rod (15) is rotatably connected to the positioning mandrel (2).

2. The turning fixture for ensuring the positional accuracy of a gun drill hole according to claim 1, characterized in that: Two positioning rods (17) are symmetrically fixedly connected to the side wall of the arc-shaped top plate (16) near the positioning mandrel (2). Several positioning holes (18) are opened on the side wall of the positioning mandrel (2), and the positioning rods (17) are movably connected to the positioning holes (18).

3. The turning fixture for ensuring the positional accuracy of a gun drill hole according to claim 1, characterized in that: The connecting assembly includes a locking bolt (7), which is movably connected to the side wall of the eccentric drill jig (1). The side wall of the pin hole (5) is provided with an internal thread (6) near the end face, and the locking bolt (7) and the internal thread (6) are matched with each other.

4. The turning fixture for ensuring the positional accuracy of a gun drill hole according to claim 1, characterized in that: The second bevel gear (13) is fixedly connected to a bearing (19) on the side wall away from the center of the first bevel gear (10), and the side wall away from the second bevel gear (13) of the bearing (19) is rotatably connected to the side wall of the cavity (9).

5. The turning fixture for ensuring the positional accuracy of a gun drill hole according to claim 1, characterized in that: The sidewall of the arc-shaped top plate (16) away from the positioning spindle (2) is fixedly connected with rubber pads (20), and the rubber pads (20) are arranged in an arc shape.

6. The turning fixture for ensuring the positional accuracy of a gun drill hole according to claim 1, characterized in that: The positioning mandrel (2) is stepped, and a circular groove (21) is provided on the end face of the positioning mandrel (2). The internal hexagonal locking block (12) is located inside the circular groove (21).

7. The turning fixture for ensuring the positional accuracy of a gun drill hole according to claim 1, characterized in that: The diameter of the left end face of the eccentric drill jig (1) is smaller than the diameter of the right end face, and the circular hole (8) is opened on the left end face of the eccentric drill jig (1).

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