A milling fixture for realizing machining in different directions by means of machine tool rotation

Abstract

This invention provides a milling fixture that enables machining in different directions by utilizing machine tool rotation. The first sidewall of the fixture body has a protrusion on its outer side for mounting the fixture on a four-axis machine tool. The bottom wall accommodates the workpiece between the first and second sidewalls. Cylindrical pins and diamond pins, using a "one-face, two-pin" positioning method, connect the workpiece to the first sidewall through a self-contained precision hole. A partition allows for workpiece removal. The partition and OK clamp are adjacent to each other on the bottom wall. Under the action of the OK clamp, the fixture clamps the workpiece by pressing it against the partition. This fixture requires only one clamping operation, using the machine tool's A-axis rotation to complete the machining of two straight grooves, two 30° angled sections opposite the straight grooves, and two 90° small planes, thus combining machining processes and improving machining efficiency. It eliminates the need for frequent workpiece loading and unloading on a conventional vertical milling machine, reducing labor intensity. The 30° angled sections are more accurately aligned with the machine tool's headstock markings by CNC rotation of the A-axis than by visual inspection, ensuring the quality of the machined parts.

Description

Technical Field

[0001] This invention belongs to the field of milling technology, specifically relating to a milling fixture that enables machining in different directions by means of machine tool rotation. Background Technology

[0002] The main chain link, a component of the artillery weapon, is, as the name suggests, connected to the product chain. In this weapon, the chain's function is to convert the rotational motion of the mechanism into the linear motion of the locking mechanism. The locking mechanism is the core component of the weapon, so the quality of the main chain link directly affects the smoothness of the chain drive, thus impacting the normal operation of the locking mechanism. Given the large production volume of artillery pieces, improving the processing efficiency of the main chain link is essential. A simplified diagram of the main chain link is shown below. Figure 1 The part 100 requires machining two straight grooves 101, two small planes 103 at a 90° angle to the straight grooves, and two oblique angles 102 at a 30° angle. Since the two straight grooves, two oblique angles, and two small planes are located in three spatial directions, a conventional three-axis machine tool cannot complete the machining in one operation.

[0003] Currently, the machining method for parts similar to the main link is as follows: The main link has two straight grooves machined on a three-axis CNC milling machine, and then two small planes at 90° and two oblique angles at 30° are machined on a conventional vertical milling machine. Generally, there are two methods for machining the 30° oblique angles: one is to rotate the spindle of the conventional vertical milling machine to a 30° angle; the second method is to use a dedicated 30° angle milling cutter. Due to space constraints, the second method is not suitable for this part. Currently, this part can only be machined using the first method, and when the machine tool is tilted, the operator must visually align it with the machine tool spindle angle scale, which introduces significant errors. Furthermore, only one 30° oblique angle can be machined at a time. To machine the small planes, the small planes need to be adjusted to be parallel to the machine tool table, and only one small plane can be machined at a time. Therefore, machining the straight groove, two 30° bevels opposite the straight groove, and two small planes at 90° opposite the straight groove of this part requires five clamping operations, and also necessitates two processes: one on a CNC milling machine and the other on a conventional vertical milling machine. Because the bevels and small planes have small machining areas and short machining times, on a conventional vertical milling machine, operators need to frequently load and unload the part. The time spent on loading and unloading is greater than the machining time, resulting in high labor intensity, low efficiency, and the control of the bevels relies entirely on manual visual alignment with the machine tool spindle scale lines, leading to low machining quality. Summary of the Invention

[0004] To address the problems of low efficiency and quality caused by the dispersed machining steps in the milling of main link parts of artillery weapons, which result in frequent clamping of parts, this application proposes a method to complete the milling of straight grooves, planes, and bevels in different directions and requiring multiple clamping operations in a single milling operation. However, achieving this functionality requires either tool rotation or part rotation. While five-axis CNC machine tools can perform single milling operations, they are expensive, limited in quantity, and unsuitable for many machining environments. This leaves part rotation as the only remaining option. However, achieving part rotation requires specialized fixtures and the rotary axes of a four-axis machine tool.

[0005] Based on the above ideas, this invention provides a milling fixture that enables machining in different directions by rotating the machine tool. By using this fixture in conjunction with the A-axis rotation of a four-axis machine tool, machining of straight grooves, bevels, and planes in different directions can be completed in a single clamping operation, which originally required five clamping operations. This combines machining steps, improves production efficiency, reduces the labor intensity of operators, and the 30-degree bevel angle is more accurate by CNC rotating the A-axis than by manually adjusting the tilting machine tool spindle, thus ensuring the machining quality of the parts.

[0006] To achieve the above objectives, the technical solution provided by this invention is:

[0007] This invention provides a milling fixture that enables machining in different directions by means of machine tool rotation, including a fixture body, a cylindrical pin, a diamond pin, a partition, and an OK clamp;

[0008] The fixture body is U-shaped and includes a bottom wall, a first side wall and a second side wall. The first side wall has a vertically extending protrusion on the outer side for clamping the milling fixture on the three-jaw chuck of the A-axis of the four-axis machine tool. The bottom wall is used to receive the workpiece to be processed between the first side wall and the second side wall.

[0009] Cylindrical pins and diamond pins are used to connect the workpiece to the first sidewall through its own precision hole in a "one-sided two-pin" positioning method, and the workpiece is positioned such that its straight groove is perpendicular to the protrusion.

[0010] The partition is used to disassemble the workpiece to be processed, and the OK clamp is used to clamp the workpiece to be processed. The partition and the OK clamp are placed adjacent to each other on the bottom wall, with the partition in contact with the workpiece to be processed and the OK clamp in contact with the second side wall. Thus, the milling fixture clamps the workpiece to be processed by pressing it through the partition under the action of the OK clamp.

[0011] Furthermore, the milling fixture also includes a support bolt and a support nut. The support bolt passes through the bottom wall of the fixture body and is locked by the support nut, and the end of the shank of the support bolt contacts the workpiece to be machined.

[0012] Furthermore, the bottom wall of the fixture body includes a first part and a second part with different thicknesses. The second part is thicker than the first part. The first part is used to receive the workpiece to be processed and through which the support bolt passes. The second part is used to receive the partition and the OK clamp.

[0013] Furthermore, the bottom wall of the fixture body is machined with stepped holes for installing support bolts, so that the heads of the support bolts do not protrude out of the fixture body.

[0014] Furthermore, the milling fixture also includes a support washer, which is sleeved on the rod of the support nut and located between the bottom wall of the fixture body and the support nut.

[0015] Furthermore, the OK clamp includes a clamp body and a clamp bolt, with the clamp body being locked in place by the clamp bolt.

[0016] The advantages of this invention are:

[0017] 1. This invention provides a milling fixture that enables machining in different directions by rotating the machine tool. The fixture body is fixed to the A-axis of a four-axis machine tool via protrusions on its outer side. The workpiece is fixed inside the fixture body using a "one-face, two-pin" positioning method, and clamped by a partition and OK clamp inside the fixture body. Therefore, this invention has a compact structure, low manufacturing cost, and convenient and quick clamping operation. For artillery main link parts, only one clamping is needed; machining in different directions—namely, machining the two straight grooves, two oblique angles relative to the straight grooves at 30°, and two small planes relative to the straight grooves at 90°—can be completed by rotating the A-axis of the four-axis machine tool. This combines machining processes, reduces part handling steps, and minimizes auxiliary time spent loading and unloading parts, greatly improving machining efficiency. It eliminates the need for frequent loading and unloading on ordinary vertical milling machines, reducing operator workload. Furthermore, the 30° oblique angles are more accurately aligned with the machine tool spindle scale by CNC rotation of the A-axis than by visual inspection, ensuring the quality of the machined parts.

[0018] 2. This invention allows the use of a four-axis CNC machine tool to replace the original ordinary vertical milling machine and CNC three-axis machine tool. Whether machining two straight grooves, two planes, or two oblique angles, the CNC machine tool operates automatically without operator intervention. This reduces dependence on operators and avoids losses caused by operator errors in ordinary milling machine machining.

[0019] 3. This invention employs a partition that facilitates part disassembly. When a part needs to be removed, simply loosen the OK clamp, pull out the partition, and then move the part to detach it from the cylindrical and diamond-shaped pins. The entire process does not require removing the OK clamp. This method improves the efficiency of part assembly and disassembly, thereby increasing part production efficiency. Attached Figure Description

[0020] The above and / or other features and advantages of the present invention will become more readily understood from the following description with reference to the accompanying drawings, which are not drawn to scale and some features are enlarged or reduced to show details of specific parts.

[0021] Figure 1 It is a schematic 3D diagram of the main link components of the artillery;

[0022] Figure 2 This is a schematic perspective view of the milling fixture of the present invention, which uses the rotation of a machine tool to perform machining in different directions and holds the parts.

[0023] Figure 3 This is a schematic front view of the milling fixture of the present invention, which uses machine tool rotation to achieve machining in different directions, when holding a part;

[0024] Figure 4 This is a schematic top view of the milling fixture of the present invention, which uses the rotation of a machine tool to achieve machining in different directions, when holding a part;

[0025] Figure 5 This is a schematic perspective view of the clamp body in this invention;

[0026] Figure 6 This is a schematic perspective view of the cylindrical pin in this invention;

[0027] Figure 7 This is a schematic perspective view of the rhomboid pin in this invention;

[0028] Figure 8 This is a schematic perspective view of the clamp body of the OK clamp in this invention.

[0029] In the diagram: 1-Clamp body, 11-Bottom wall, 111-First part, 112-Second part, 113-Stepped hole, 114-Threaded hole, 12-First side wall, 121-Pin hole, 13-Second side wall, 14-Protrusion; 2-Cylindrical pin, 21-Cylindrical pin washer, 22-Cylindrical pin nut; 3-Rhomboid pin, 31-Rhomboid pin washer, 32-Rhomboid pin nut; 4-Partition plate; 5-OK clamp, 51-Clamp body, 52-Clamp bolt; 6-Support bolt; 7-Support nut; 8-Support washer; 100-Workpiece to be processed, 101-Straight groove, 102-Bevel angle, 103-Small plane. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and exemplary embodiments thereof. It should be noted that the following detailed description of the present invention is for illustrative purposes only and is not intended to limit the scope of the invention.

[0031] It should be noted that, in the context of this invention, the terms “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “inner,” “outer,” “clockwise,” and “counterclockwise,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0032] Furthermore, terms such as "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0033] This invention provides a milling fixture that enables machining in different directions by means of machine tool rotation, for use in... Figure 1 During the machining of the two straight grooves 101, the two oblique angles 102 at 30° to the straight grooves, and the two small planes 103 at 90° to the straight grooves of the main link component 100 shown, the part is clamped. Using this fixture, the part to be machined only needs to be clamped once, and the machining of the straight grooves, oblique angles and small planes in different directions can be achieved by rotating one axis of the machine tool, thus combining the machining processes.

[0034] First, the overall reference Figures 2 to 4 As an exemplary embodiment of the present invention, a milling fixture that achieves machining in different directions by means of machine tool rotation includes a fixture body 1, a cylindrical pin 2, a diamond pin 3, a partition 4, and an OK clamp 5. The fixture body 1 is used to install itself onto the machine tool 100 to be machined, especially the A-axis of a four-axis machine tool. The cylindrical pin 2 and the diamond pin 3 can jointly connect the workpiece 100 to the fixture body 1 on one side through their pre-machined precision holes. On the other hand, the fixture body 1 uses the partition 4 and the OK clamp 5 to press and squeeze the other side of the workpiece 100 to be machined, thereby clamping the workpiece 100 to withstand the cutting force during machining.

[0035] Combination Figure 5 The fixture body 1 is generally U-shaped and includes a bottom wall 11, a first side wall 12 and a second side wall 13. The first side wall 12 has a vertically extending protrusion 14, especially a cylindrical protrusion, on the outside of the fixture body for clamping the milling fixture on the three-jaw chuck of the A-axis of the four-axis machine tool. The first side wall 12 has two pin holes 121 above the protrusion 14, which pass through the cylindrical pin 2 and the diamond pin 3 respectively, to connect the workpiece 100 to be processed.

[0036] The bottom wall 11 of the fixture body 1 is used to receive the workpiece 100 to be processed on the inner side, that is, between the first side wall 12 and the second side wall 13. In order to facilitate the installation and clamping of the workpiece to be processed, in some embodiments of the present invention, the bottom wall 11 includes a first part 111 and a second part 112 with different thicknesses. The bottom surfaces of the two parts are flush. The thickness of the second part 112 is greater than that of the first part 111. The first part 111 is used to receive the workpiece 100 to be processed and to pass through the support bolt 6 (described below). The first part 111 is provided with a hole perpendicular to the axis of the protrusion for installing the support bolt 6, especially a stepped hole 113. The second part 112 is used to receive the partition 4 and the OK clamp 5. The second part 112 is machined with a threaded hole 14 for fastening the OK clamp.

[0037] Combination Figure 6 and Figure 7 The cylindrical pin 2 and the diamond pin 3 are used to connect the workpiece 100 to the first sidewall 12 through its own precision hole, specifically the pin hole 121 on the first sidewall 12, in a "one-sided, two-pin" positioning method. The workpiece 100 is positioned such that its straight groove 101 is perpendicular to the protrusion 14, which can be perpendicular to the axis of the cylindrical protrusion. The cylindrical pin 2 can pass through the precision hole of the workpiece 100 and the pin hole 121 on the first sidewall 112 and be fitted with a cylindrical pin washer 21, and then locked by a cylindrical pin nut 22. Similarly, the diamond pin 3 can pass through the precision hole of the workpiece 100 and the pin hole 121 on the first sidewall 112 and be fitted with a diamond pin washer 31, and then locked by a diamond pin nut 32.

[0038] Combination Figure 8 The OK clamp 5 is used to clamp the workpiece 100 to be processed. The partition 4 and the OK clamp 5 are arranged adjacent to each other on the bottom wall 11, with the partition 4 in contact with the workpiece 100 and the OK clamp 5 in contact with the second side wall 13. Thus, the milling fixture clamps the workpiece by pressing it against the partition 4 under the action of the OK clamp 5. The OK clamp structure is a known and mature technology. The present invention can use a type including a clamp body 51 and a clamp bolt 52, with the clamp body 51 locked by the clamp bolt 52.

[0039] The partition 4 is rectangular in shape and is used to disassemble the part 100 to be processed. Specifically, after the straight grooves, bevels, and small planes of the part are machined, the part needs to be removed. First, the OK clamp is loosened so that the wedge of the OK clamp is in a relaxed state. At this time, the partition 4 is simply pulled out perpendicular to the axis of the protrusion. Then, the part is moved to the right parallel to the axis of the protrusion to disengage the part from the cylindrical pin and the diamond pin, without removing the OK clamp. When installing a new part to be processed, after installing the part and the partition, the OK clamp is locked. In this way, the efficiency of part assembly and disassembly can be improved, thereby improving the production efficiency of parts. By comparison, those skilled in the art will understand that the partition 4 should be selected with a thickness greater than the length of the cylindrical pin and the diamond pin installed on the part, so that the part can be removed after the partition 4 is removed.

[0040] To assist in supporting the workpiece to be machined, improve machining strength, and prevent vibration during machining, the milling fixture of the present invention preferably also includes a support bolt 6 and a support nut 7, such as... Figure 3 Clearly visible, the support bolt 6 passes through the stepped hole 113 on the bottom wall 11 of the fixture body 1, particularly on the first part 111, and is locked by the support nut 7. The end of the shank of the support bolt 6 contacts the workpiece 100 to provide support. The stepped hole 113 prevents the head of the support bolt 6 from protruding outside the fixture body 1, making the overall structure of the fixture compact.

[0041] Furthermore, to prevent the support nut from loosening and to maintain the firmness of the support bolt in supporting the part, the milling fixture may also include a support washer 8, which is sleeved on the rod of the support nut 7 and located between the bottom wall 11 of the fixture body 1 and the support nut 7.

[0042] The working process of the milling fixture provided by this invention, which achieves machining in different directions by means of machine tool rotation, is as follows:

[0043] Step S1: First, insert the protrusion 14 of the fixture body 1 into the three-jaw chuck of the A-axis of the four-axis machine tool, and align the fixture.

[0044] Step S2: Insert the two positioning pins, namely cylindrical pin 2 and diamond pin 3, into the two pin holes 121 on the first side wall 12 of the fixture body 1, and tighten them with nuts respectively.

[0045] Step S3: Insert the two precision holes of the part to be processed 100 into the two positioning pins. In order to ensure the part can be installed and removed, insert a partition 4 between the part and the OK clamp 5. After the part is aligned, lock the OK clamp 5.

[0046] Step S4: Move the support bolt 6 below the part upwards until it contacts the lower end face of the part, and then tighten the support nut 7. At this point, the fixture and part are installed, and the machining of the two straight grooves on the part can begin using the fixture in conjunction with the A-axis. After machining the straight grooves, rotate the A-axis 90° to machine two small planes 90° opposite to the straight grooves. After machining the 90° small planes, rotate the A-axis 30° to machine two 30° bevels. In this way, by using the milling fixture of this invention in conjunction with a four-axis machine tool, all machining of different directions of artillery main link parts can be completed with just one setup.

[0047] Therefore, as described above, the present invention has a compact structure, low manufacturing cost, and convenient and quick clamping operation. For artillery main chain link parts, only one clamping is required, and the machining in different directions can be completed by rotating the A-axis of a four-axis machine tool. This includes machining the two straight grooves of the part, the two oblique angles of 30° relative to the straight grooves, and the two small planes of 90° relative to the straight grooves. This achieves the merging of machining processes, reduces the number of parts turnover links, reduces the auxiliary time for loading and unloading parts, and greatly improves machining efficiency. It eliminates the need for operators to frequently load and unload parts on ordinary vertical milling machines, reducing the operator's labor intensity. Moreover, the 30-degree oblique angle is more accurate when the A-axis is rotated by CNC than when visually aligning with the machine tool spindle scale line, ensuring the machining quality of the parts and making the transmission mechanism, such as chain drive, more stable, thereby ensuring the normal operation of core components such as the locking mechanism.

[0048] Furthermore, this invention allows for the replacement of traditional vertical milling machines and three-axis CNC machine tools with four-axis CNC machine tools. Whether machining two straight grooves, two planes, or two bevels, the CNC machine tool operates automatically without operator intervention. This reduces reliance on operators and avoids losses caused by operator errors on conventional milling machines. In the machining industry, this fixture, due to its simple structure, low manufacturing cost, and high versatility, provides strong support for production and manufacturing, and is worthy of promotion and reference in the processing and production of similar parts.

[0049] Finally, it should be noted that the features mentioned and / or shown in the above description of exemplary embodiments of the present invention can be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. These combined or substituted technical solutions should also be considered to be included within the scope of protection of the present invention.

Claims

1. A milling fixture that achieves machining in different directions by means of machine tool rotation, characterized in that: Includes clamp body, cylindrical pin, diamond pin, partition and OK clamp; The fixture body is U-shaped and includes a bottom wall, a first side wall and a second side wall. The first side wall has a vertically extending protrusion on its outer side for clamping the milling fixture on the three-jaw chuck of the A-axis of a four-axis machine tool. The bottom wall is used to receive the workpiece to be processed between the first side wall and the second side wall. The cylindrical pin and the diamond pin are used to connect the workpiece to the first sidewall through its own precision hole in a "one-sided two-pin" positioning method, and the workpiece is positioned such that its straight groove is perpendicular to the protrusion. The partition is used to disassemble the part to be processed, and the OK clamp is used to clamp the part to be processed. The partition and the OK clamp are arranged adjacent to each other on the bottom wall, and the partition is in contact with the part to be processed, and the OK clamp is in contact with the second side wall. Thus, the milling fixture clamps the part to be processed by squeezing it through the partition under the action of the OK clamp.

2. The milling fixture for machining in different directions by means of machine tool rotation according to claim 1, characterized in that: It also includes a support bolt and a support nut, the support bolt passing through the bottom wall of the fixture body and being locked by the support nut, and the end of the shank of the support bolt contacting the workpiece to be processed.

3. The milling fixture for machining in different directions by means of machine tool rotation according to claim 2, characterized in that: The bottom wall of the clamp body includes a first part and a second part with different thicknesses. The second part is thicker than the first part. The first part is used to receive the workpiece to be processed and pass through the support bolt. The second part is used to receive the partition and the OK clamp.

4. The milling fixture for machining in different directions by means of machine tool rotation according to claim 2 or 3, characterized in that: The bottom wall of the fixture body is machined with stepped holes for installing the support bolts, so that the head of the support bolts does not protrude out of the fixture body.

5. The milling fixture for machining in different directions by means of machine tool rotation according to claim 2 or 3, characterized in that: It also includes a support washer, which is sleeved on the rod portion of the support nut and located between the bottom wall of the clamp body and the support nut.

6. The milling fixture for machining in different directions by means of machine tool rotation according to claim 1 or 2, characterized in that: The OK clamp includes a clamp body and a clamp bolt, and the clamp body is locked by the clamp bolt.

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