Specialized machining tooling for small drive arms

Abstract

This solution discloses a special machining fixture for a small drive arm, including a fixture body with a through workpiece mounting hole. A V-shaped pressure plate assembly is installed within the workpiece mounting hole, which is a stepped hole adapted to accommodate and embed the workpiece. It also includes a detachable side pressure plate assembly. The side pressure plate assembly includes a side pressure plate; the side pressure plate and the stepped surface of the stepped hole in the workpiece mounting hole respectively clamp the A and B surfaces of the workpiece. The advantages of this solution are: 1. Stable and reliable clamping; 2. All machining can be completed in one clamping operation without mid-process disassembly and adjustment; 3. The side pressure plate adopts a reverse-pull design, eliminating the risk of damage or deformation to the workpiece surface; 4. The flash avoidance groove effectively avoids the flash cast on the workpiece, increasing compatibility; 6. The workpiece is small in size, and the side notch of the workpiece mounting hole facilitates the machining of the G-groove with a cutting tool; 5. Easy disassembly and assembly.

Description

Technical Field

[0001] This utility model relates to the field of workpiece clamping devices, specifically a special machining fixture for a small drive arm. Background Technology

[0002] Drive arms are crucial components in the field of mechanical automation. Different application scenarios, different mechanical equipment, different functional requirements, and different motion designs result in varying drive arm shape and size requirements. Therefore, many drive arms cannot use universal specifications and need to be manufactured custom-made. Drive arm manufacturing typically involves casting a metal blank, followed by machining. Due to the special shape and structure of specialized drive arms, general-purpose tooling fixtures often cannot meet the clamping requirements. The applicant recently needed to machine a batch of small drive arms of special specifications for use on a small-sized, high-precision machine, requiring high dimensional accuracy and flatness of the parts' surfaces, holes, and grooves. The main body of the drive arm is a thin, elongated oval shape, with surfaces A and B parallel to a reference plane; one end of the main body is a thick cylinder with surfaces C and D at its two ends. The machining requirements are to maintain the parallelism of surfaces C and D to the reference plane, then drill holes E and F perpendicularly at the two centers of the elongated oval, and finally, create a groove G on surface C along the radial direction of hole F. Traditional vertical three-axis machining centers struggle to guarantee the accuracy and stability of the workpiece machining. When using a five-axis CNC machine tool, how to clamp the workpiece to expose the machining surface, facilitate tool movement and machining, meet machining accuracy requirements, and also take into account machining efficiency and achieve rapid clamping becomes a problem that needs to be solved. Summary of the Invention

[0003] Based on the above problems, this utility model provides a special machining fixture for a small drive arm, which can be adapted to a five-axis linkage CNC machine tool and complete the entire machining of the workpiece in one clamping.

[0004] To achieve the purpose of this invention, the present invention adopts the following technical solution: A special machining fixture for a small drive arm, comprising a fixture body, a workpiece mounting hole through which a V-shaped pressure plate assembly is provided, and a workpiece mounting hole containing a V-shaped pressure plate assembly. The workpiece mounting hole is a stepped hole that can be fitted with a workpiece. It also includes a detachable side plate assembly; the side plate assembly includes a side plate; The side pressure plate and the stepped surface of the workpiece mounting hole clamp the A and B surfaces of the workpiece, respectively.

[0005] Preferably, the tooling body is provided with a side pressure plate mounting groove; the side pressure plate is adapted to be embedded in the side pressure plate mounting groove.

[0006] Preferably, the side plate assembly also includes a side plate bolt fixed at one end to the side plate; the tooling body is provided with a side plate bolt through hole, through which the side plate bolt passes and is connected to the side plate nut.

[0007] Preferably, one end of the lateral pressure plate is provided with a lateral pressure plate support boss, and the other end is provided with an A-side positioning post; a B-side positioning post extends from the stepped surface of the workpiece mounting hole toward the lateral pressure plate, and the A-side positioning post and the B-side positioning post are positioned correspondingly.

[0008] Preferably, the ends of the positioning posts on side A and side B are detachable and replaceable.

[0009] Preferably, the hole wall shape of the workpiece mounting hole relative to the direction of movement of the V-shaped pressure plate assembly is V-shaped.

[0010] Preferably, the workpiece mounting hole has a notch adapted to machine the G-groove.

[0011] Preferably, the stepped surface of the workpiece mounting hole is provided with an E-hole machining hole.

[0012] Preferably, the sidewall of the workpiece mounting hole is provided with a flash clearance groove.

[0013] Preferably, a baffle assembly is also included; the baffle assembly is partially fixed outside the workpiece mounting hole.

[0014] The beneficial effects of this plan are: 1. Stable and reliable clamping; 2. All processing can be completed in one clamping, without the need for disassembly and adjustment in the middle; 3. The side pressure plate adopts a reverse pull design, eliminating the risk of damage or deformation to the workpiece surface; 4. The flash clearance groove can effectively avoid the flash of the workpiece casting, increasing the compatibility effect; 6. The workpiece volume is small, and the side notch of the workpiece mounting hole can facilitate the machining of G grooves by the cutting tool; 5. Easy to disassemble and assemble. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the drive arm; Figure 2 yes Figure 1 XX sectional view; Figure 3 It is a 3D view of the semi-finished workpiece of the drive arm; Figure 4 This is a three-dimensional view of the semi-finished workpiece of the drive arm from another perspective; Figure 5 This is a schematic diagram of the structure of this utility model; Figure 6 This is an exploded view of some components of this utility model; Figure 7 This is an exploded view of some components of this utility model from another perspective; Figure 8 This is a structural schematic diagram of the side pressure plate assembly; Figure 9 This is a diagram showing the usage state of this utility model; Figure 10 This is a usage diagram from another perspective of this utility model.

[0016] Among them: chuck 01, chuck guide groove 011, tooling body 02, tooling fixing bolt 021, workpiece mounting hole 022, flash clearance groove 0221, B-side positioning post 023, side pressure plate mounting groove 024, side pressure plate bolt through hole 025, E-hole machining hole 026, V-shaped pressure plate assembly 03, side pressure plate assembly 04, side pressure plate 041, A-side positioning post 042, side pressure plate support boss 043, side pressure plate bolt 044, side pressure plate nut 045, baffle assembly 05; A, B, C, and D are the four faces on the workpiece, E and F are the two holes on the workpiece, and G is the groove on the workpiece. Detailed Implementation

[0017] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0018] Example 1 Example 1 presents a special machining fixture designed for small drive arms, which is particularly suitable for high-precision machining of drive arm casting blanks on a five-axis CNC machine tool.

[0019] First, the structural characteristics of the small drive arm are described in detail. In this embodiment, the small drive arm is made of steel through casting and then precision-machined using a five-axis CNC machine tool to obtain the final product. Figure 1 , Figure 2As shown, the main structure of the finished drive arm is a flattened elongated oval, with its two sides defined as surface A and surface B, both of which are strictly parallel to the reference plane. It should be noted that this reference plane coincides precisely with the parting line during the casting process. The elongated oval main body can be further divided into three areas: upper, middle, and lower. The upper part has a through-hole stepped hole E at the center of the upper part of the oval, with the left opening larger than the right opening to meet specific assembly requirements. The middle part retains a reinforcing rib structure at the center of the oval's width to enhance overall structural strength, while the remaining parts are thinned and lightened using the casting mold to reduce overall weight. The lower part is designed as a cylinder, with its axis passing precisely through the center of the lower part of the oval. The cylinder's height is approximately 2.5 times the thickness of the main body, and it connects to the main body near the middle. The two end faces of the cylinder are defined as surface C and surface D, which are also required to be parallel to the reference plane. A stepped hole F is formed through the cylinder along its axial direction, with a smaller dimension at the left end and a larger dimension at the right end. Additionally, a groove G is formed on the right end face of the cylinder, surface C. The length of groove G is perpendicular to the length of the main body and orthogonal to the center of the lower cylinder. Both ends of groove G extend to the sides of the cylinder to meet specific functional requirements. In this embodiment, the main processing areas of the workpiece include surfaces C and D, holes E and F, and groove G.

[0020] Next, the special machining tooling for the small drive arm in this embodiment will be described in detail. For example... Figure 5 , Figure 6 , Figure 7 As shown, the machining fixture in this embodiment is mainly composed of a fixture body 02, which is securely fixed to the chuck 01 via chuck guide grooves 011 and fixture fixing bolts 021. The chuck 01 is cylindrical, and its upper end face is provided with 6 chuck guide grooves 011 arranged radially at equal angles. The fixture body 02 can be selected and fixed to two opposite chuck guide grooves 011 according to actual machining requirements.

[0021] The fixture body 02 is a flat rectangular parallelepiped, placed vertically, with a workpiece mounting hole 022 running through its center. The workpiece mounting hole 022 is a stepped hole, with a larger opening at one end and a smaller opening at the other. Its shape and size are carefully designed to fit and embed the workpiece to be processed. Simultaneously, the depth of the hole matches the height of the cylindrical workpiece, ensuring the workpiece can be securely mounted on the fixture. When the workpiece is embedded in the workpiece mounting hole 022, surface C of the workpiece will be exposed on the larger opening side of the stepped hole, while surface D will be exposed on the smaller opening side, facilitating subsequent processing operations.

[0022] To ensure the stability of the workpiece during processing, this embodiment also includes a side pressure plate 041. The side pressure plate 041 is located on the larger side of the stepped hole in the workpiece mounting hole 022, facilitating easy assembly and disassembly. Once installed, the side pressure plate 041 firmly presses against surface A of the workpiece, while simultaneously engaging with the stepped surface of the stepped hole in the workpiece mounting hole 022 to press against surface B of the workpiece, thus achieving stable fixation of the workpiece and ensuring smooth processing.

[0023] This is the most basic embodiment of the solution. Subsequent embodiments will be evolved and optimized based on this to further improve processing efficiency and processing quality.

[0024] Example 2 Example 2 is an optimization based on Example 1.

[0025] For details, please refer to Figure 8 As shown, in this embodiment, the core component that achieves the key function of accurately pressing against the B side of the workpiece is the side pressure plate assembly 04, and the side pressure plate 041 is one of the indispensable important parts in the side pressure plate assembly 04.

[0026] The side clamping plate 041 is elongated in shape. In the workpiece clamping direction, its left end features a specially protruding side clamping plate support boss 043, while the right end has a corresponding protruding A-side positioning post 042. In the middle of the side clamping plate 041, along the axial direction of the workpiece mounting hole 022, a side clamping plate bolt 044 is installed, and a side clamping plate nut 045 is threadedly connected to it to ensure a stable connection.

[0027] Correspondingly, the right side of the tooling body 02 is carefully designed with a lateral pressure plate mounting groove 024. The shape and size of this groove are precisely calculated to perfectly fit and engage with the lateral pressure plate 041. At the corresponding position at the bottom of the lateral pressure plate mounting groove 024, a lateral pressure plate bolt through hole 025 is provided, penetrating the thickness direction of the tooling body 02. This through hole allows the lateral pressure plate bolt 044 to pass through smoothly. Furthermore, at the corresponding position on the stepped surface of the workpiece mounting hole 022, a B-side positioning post 023 is protruded for precise positioning and holding the B-side of the workpiece.

[0028] After the lateral pressure plate assembly 04 is installed, the lateral pressure plate 041 can be precisely embedded in the pressure plate mounting groove 024, and the lateral pressure plate bolt 044 passes through the lateral pressure plate bolt through hole 025. At this time, the pressure plate support boss 043 precisely abuts against the bottom of the lateral pressure plate mounting groove 024, providing stable support. Simultaneously, the B-side positioning post 023 is positioned opposite to the A-side positioning post 042, precisely abutting against the B-side and A-side of the workpiece respectively. Subsequently, the lateral pressure plate nut 045 is threadedly connected to and tightened with the lateral pressure plate bolt 044 on the other side of the fixture body 02, thereby forming an effective counter-tension fixing effect on the workpiece. This ingenious structural design not only ensures the workpiece remains highly stable during processing but also cleverly avoids problems such as deformation caused by applying additional pressure to the workpiece.

[0029] It is worth mentioning that the lateral pressure plate support boss 043, the lateral pressure plate bolt 044, and the A-side positioning post 042 ingeniously form a lever relationship. Based on this design principle, in actual operation, sufficient pressure can be obtained on the A-side positioning post 042 without applying excessive tension to the lateral pressure plate bolt 044, thereby achieving reliable fixation of the workpiece.

[0030] Furthermore, considering wear and tear during actual use, the ends of both the B-side positioning post 023 and the A-side positioning post 042 are designed to be detachable and replaceable. When the ends wear down due to long-term use, operators can easily remove the old positioning post ends and replace them with new ones, thus maintaining positioning accuracy and ensuring processing quality.

[0031] Same as Example 1.

[0032] Example 3 This embodiment is an optimization based on embodiment 2.

[0033] Continue to refer to Figure 5 , Figure 6 and Figure 7 As shown, in the specific design of this embodiment, an additional through-hole E-hole 026 is carefully opened on the stepped surface of the stepped hole 022 of the workpiece mounting hole. The opening of this E-hole 026 has a specific significance. It accurately exposes the machining position of the E-hole, providing convenient conditions for the subsequent machining operation of the E-hole, so that the machining tool can smoothly reach the designated position to complete the machining of the E-hole.

[0034] Furthermore, in the tooling design involved in this embodiment, the sidewall of the large opening side of the 022 stepped hole mounting hole on the workpiece has undergone refined structural optimization, with a notch of a specific shape and position designed. Specifically, this notch is precisely opened in the position area corresponding to both ends of the G groove on the workpiece. The core purpose of this notch design is to provide sufficient and unobstructed movement space for the tool machining the G groove, ensuring that the tool can smoothly and accurately complete the cutting of the G groove according to the predetermined machining trajectory, thereby effectively avoiding problems such as machining failure or tool damage caused by space limitations or interference.

[0035] In this embodiment, a V-shaped clamping plate assembly 03 is innovatively added. As a common functional component in the field of tooling and fixtures, the V-shaped clamping plate assembly 03 is cleverly installed above the workpiece mounting hole 022 in this embodiment. This assembly, through fine adjustment of the adjusting screw, enables smooth lifting and lowering movement of the V-shaped clamping plate. This lifting function allows the V-shaped clamping plate to precisely conform to the elongated oval contour of the upper end of the workpiece, thereby achieving effective clamping of the upper end of the workpiece and ensuring the stability of the workpiece during processing.

[0036] In addition, this embodiment also includes a baffle assembly 05. The baffle assembly 05 is securely fixed to the large opening of the stepped hole in the workpiece mounting hole 022, and is detachably connected to the fixture body 02 via two bolts. This design allows the baffle assembly 05 to effectively block the upper half of the large opening of the stepped hole in the workpiece mounting hole 022, while the other end of the E-hole remains exposed to meet the processing requirements of the E-hole. The presence of the baffle assembly 05 not only prevents the workpiece from accidentally detaching during processing, ensuring processing safety, but also facilitates the smooth operation of the V-shaped pressure plate during lifting and lowering, preventing interference with the workpiece or other components.

[0037] Furthermore, this embodiment features a unique design for the shape of the sidewall below the workpiece mounting hole 022, framing it as an upward-opening V-shape. This V-shape echoes the downward-opening V-shape of the V-shaped pressure plate, creating a clever limiting mechanism. It effectively limits the cylindrical portion below the workpiece, ensuring more stable and reliable clamping in the vertical direction, further enhancing the workpiece's stability during processing.

[0038] Finally, this embodiment also features a flash clearance groove 0221 specifically designed on the side wall below the workpiece mounting hole 022. The flash clearance groove 0221 extends along the parting surface, which happens to be the area where a large amount of flash is easily generated during workpiece casting. Through the rational design of the flash clearance groove 0221, the clamping point on the side wall below the workpiece mounting hole 022 can cleverly avoid the flash area, thereby ensuring the stability of the clamping and effectively guaranteeing that the machining accuracy is not affected by the flash.

[0039] Same as Example 2.

[0040] This embodiment is a relatively preferred embodiment of the present solution.

[0041] The following is a detailed description of the usage process of this embodiment: In the initial stage of operation, it is necessary to ensure that the fixture body 02 is fixed on the chuck 01 in a stable and precise manner. Then, the fixture is aligned and straightened according to traditional process specifications to ensure the reference accuracy of subsequent processing. After completing the above preparations, the side pressure plate assembly 04 is removed from the fixture, and the V-shaped pressure plate assembly 03 is manipulated to retract upward to a suitable position, leaving sufficient space for workpiece installation.

[0042] Insert the workpiece to be processed into the workpiece mounting hole 022. During the placement process, special attention should be paid to ensure that the lower cylindrical part of the workpiece is accurately placed on the side wall below the workpiece mounting hole 022. Any burrs that may exist on the workpiece should be accurately placed in the burr relief groove 0221 to avoid the burrs interfering with subsequent processing and clamping stability.

[0043] Next, install the side pressure plate assembly 04 and pre-tighten the side pressure plate 041. This operation ensures that the A side of the workpiece is tightly fitted to the end of the A side positioning post 042, while ensuring that the B side of the workpiece is reliably in contact with the end of the B side positioning post 023, thereby achieving precise horizontal positioning of the workpiece.

[0044] Then, adjust the V-shaped pressure plate assembly 03 downwards, carefully adjusting the workpiece's posture during this process to ensure it is completely aligned. Once the V-shaped pressure plate accurately presses against the upper circumferential surface of the workpiece, use a torque wrench to tighten the V-shaped pressure plate assembly 03 to a set torque of 90N, thus ensuring reliable clamping of the upper part of the workpiece. Finally, use the side pressure plate nut 045 to finally tighten the side pressure plate 041, completing the overall fixation of the workpiece on the fixture.

[0045] Figure 9 and Figure 10 The diagram clearly illustrates the state of this embodiment in actual use. As can be clearly seen from the figure, surface C of the workpiece is exposed on the larger side of the stepped hole 022 of the workpiece mounting hole, providing convenient space for related machining operations; surface D is exposed on the smaller side of the stepped hole 022 of the workpiece mounting hole, facilitating machining operations from that direction; one end of the machining end of hole E is exposed on the larger side of the stepped hole 022 of the workpiece mounting hole, and the other end is exposed at the opening of machining hole 026 of hole E, ensuring smooth machining of hole E; one end of hole F is located on surface C, and the other end is located on surface D; groove G is located on surface C. All these parts are in an open and machinable state, enabling the smooth completion of the corresponding machining processes.

[0046] Figure 3 , Figure 4This presents the state of the workpiece at the midpoint of the processing, where... Figure 3 correspond Figure 9 The position in the middle, Figure 4 correspond Figure 10 The position of the workpiece in the diagram is shown in the two images. It can be clearly observed that the C and D surfaces and the E hole have been machined, but the F hole and the G groove have not yet been machined and are still in a state of waiting to be machined.

Claims

1. A special machining fixture for a small drive arm, comprising a fixture body (02), a workpiece mounting hole (022) extending through the fixture body (02), and a V-shaped pressure plate assembly (03) disposed within the workpiece mounting hole (022), characterized in that, The workpiece mounting hole (022) is a stepped hole that can be fitted with a workpiece; It also includes a detachable side plate assembly (04); the side plate assembly (04) includes a side plate (041); The stepped surfaces of the side pressure plate (041) and the stepped holes of the workpiece mounting hole (022) respectively clamp the A and B surfaces of the workpiece.

2. The machining tooling for small drive arms according to claim 1, characterized in that, The tooling body (02) is provided with a side pressure plate mounting groove (024); the side pressure plate (041) is adapted to be embedded in the side pressure plate mounting groove (024).

3. The machining tooling for small drive arms of claim 2, wherein, The side plate assembly (04) also includes a side plate bolt (044) with one end fixed to the side plate (041); the tooling body (02) is provided with a side plate bolt through hole (025), the side plate bolt (044) passes through the side plate bolt through hole (025) and is connected to the side plate nut (045).

4. The machining tooling for small drive arms according to claim 2 or 3, characterized in that, One end of the side pressure plate (041) is provided with a side pressure plate support boss (043), and the other end is provided with an A-side positioning post (042); a B-side positioning post (023) extends from the stepped surface of the workpiece mounting hole (022) toward the side pressure plate (041), and the A-side positioning post (042) and the B-side positioning post (023) are positioned corresponding to each other.

5. The compact drive arm special machining tooling of claim 4, wherein, The ends of the positioning post (042) on side A and the positioning post (023) on side B are detachable and replaceable.

6. A machining tool for small driving arms according to claim 1 or 2 or 3, characterized in that the workpiece The wall shape of the mounting hole (022) relative to the direction of movement of the V-shaped pressure plate assembly (03) is V-shaped.

7. The machining tooling for small drive arms according to claim 1 or 2 or 3, characterized in that, The workpiece mounting hole (022) is provided with a notch for machining the G groove.

8. A machining tool for small driving arms according to claim 1 or 2 or 3, characterized in that the workpiece Mounting hole (022) The stepped surface of the stepped hole is provided with E-hole machining hole (026).

9. The compact drive arm dedicated machining tooling fixture according to claim 1 or 2 or 3, characterized by, The sidewall of the workpiece mounting hole (022) is provided with a flash clearance groove (0221).

10. A machining tool for small driving arms according to claim 1 or 2 or 3, characterized in that, It also includes a baffle assembly (05); the baffle assembly (05) is partially fixed outside the workpiece mounting hole (022).

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