A center jig for fixing a bar-shaped part

Abstract

The utility model discloses a kind of center frame for fixing bar parts, including main body frame, support adjustment mechanism and two clamping arms;Two The bending of the clamping arm is hinged on the main body frame, two The clamping arm is oppositely laid out;The front end of two The clamping arm is used to clamp workpiece at clamping station;The support adjustment mechanism is installed on The main body frame, and located between two The clamping arm;The support end of The support adjustment mechanism is towards clamping station.The utility model center frame is cooperatively designed by hinged clamping arm and central support adjustment mechanism, realizes the self-adaptive clamping and stable three-point support to workpiece, effectively suppresses bending vibration, improves machining precision and efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of machining technology, and in particular relates to a center frame for fixing rod-shaped parts. Background Technology

[0002] In the field of machining, the center rest is a key tooling used to support slender shaft parts (such as mandrels and bars), designed to prevent the workpiece from bending, vibrating, or deforming during machining due to its own weight or cutting forces, thereby ensuring machining accuracy. In existing technologies, center rests often adopt multi-point support structures, such as radially fixing the workpiece through multiple independently adjustable top wheels or support claws (e.g., a four-wheel center rest), or using a combination of V-blocks and bolt clamping (e.g., a rod-shaped part holder). However, this type of structure has significant shortcomings: First, the adjustment of the support point position usually relies on manual operation (such as tightening lead screws or bolts), which is inefficient and makes it difficult to ensure uniform force distribution at each point, easily leading to workpiece coaxiality deviation. Second, for non-circular or variable-diameter workpieces, fixed support claws cannot adapt to the workpiece shape, easily causing scratches on the workpiece surface due to excessive local tightness or insufficient contact leading to vibration (such as the poor anti-vibration effect mentioned earlier). In addition, some support frames adopt a multi-layer platform design (such as a double support platform) to increase stability, but such structures occupy a lot of space and lack active support for the workpiece center, making it difficult to suppress mid-section deflection deformation when machining rod-shaped parts with a large length-to-diameter ratio. Therefore, the main problem of existing technology is: how to achieve a fast, adaptive, and uniform clamping force distribution without damaging the workpiece, effectively suppressing bending vibration and deformation of slender rod-shaped parts during machining. This problem directly affects machining accuracy and efficiency, especially in high-speed cutting or high-precision shaft parts (such as engine shafts and guide rods). Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a center frame for fixing rod-shaped parts, which addresses the shortcomings of the prior art. The center frame achieves adaptive clamping and stable three-point support for the workpiece through the coordinated design of the hinged clamping arm and the central support adjustment mechanism, effectively suppressing bending vibration and improving processing accuracy and efficiency.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a central frame for fixing rod-shaped parts, including a main frame, a support and adjustment mechanism and two clamping arms; The two clamping arms are hinged to the main frame at their bends, and the two clamping arms are arranged opposite each other; the front ends of the two clamping arms are used to clamp the workpiece at the clamping station. The support adjustment mechanism is mounted on the main frame and located between the two clamping arms; The top of the support adjustment mechanism faces the clamping position.

[0005] The aforementioned center frame for fixing rod-shaped parts has a set screw at the rear end of each clamping arm. The set screw is mounted on the main frame. When the set screw pushes forward, the front end of the clamping arm moves toward the clamping position.

[0006] The aforementioned center frame for fixing rod-shaped parts includes a support adjustment mechanism comprising a rotating unit, a rotating frame, an adjusting screw, and a top rod. The main frame has a limiting guide hole, the push rod is set in the limiting guide hole, and the front end extends out of the limiting guide hole toward the clamping position; the limiting guide hole has the function of preventing the push rod from rotating. The rotating frame is installed at the rear end of the limiting guide hole, and the rotating unit is installed on the rotating frame; The rear end of the adjusting screw is connected to the rotating unit via a transmission connection, and the front end of the adjusting screw is connected to the rear end of the push rod via a threaded transmission connection.

[0007] The aforementioned rod-shaped parts are fixed with a central frame. The main frame is also equipped with a locking component, which includes a pull rod and a locking handwheel. The top rod has an elongated through-hole groove. The end of the pull rod passes through the elongated through-hole groove and is threadedly connected to the locking handwheel. The head of the pull rod presses on the top rod, and the end of the locking handwheel presses on the main frame.

[0008] The aforementioned rod-shaped parts are fixed with a central frame, and the outer side of the limiting guide hole is an open structure, on which a pressure plate can be detachably installed.

[0009] The aforementioned rod-shaped parts are fixed with a central frame. The rotating unit includes a handle and a reducer. The input end of the reducer is connected to the handle, and the output end of the reducer is connected to the adjusting screw. The reducer is mounted on the rotating frame. The aforementioned rod-shaped parts are fixed by a central frame, and the output end of the reducer and the adjusting screw are connected by a coupling.

[0010] The aforementioned rod-shaped parts are fixed with a central frame, and the front end of the coupling is connected to the adjusting screw via a tapered pin; the rear end of the coupling is connected to the output end of the reducer via a flat key.

[0011] The aforementioned rod-shaped parts are fixed with a central frame, and the front end of the top rod is detachably fitted with a top block. Compared with the prior art, this utility model has the following advantages: The center frame for fixing rod-shaped parts effectively solves the core problems of uneven clamping force distribution and easy bending and vibration of the workpiece in the prior art through the coordinated design of hinged clamping arms and central support adjustment mechanism. Specifically, the bends of the two clamping arms are hinged to the main frame, which allows it to adapt to the shape of workpieces with different diameters. The clamping force is evenly distributed through the lever principle, avoiding workpiece surface damage caused by local stress concentration. This overcomes the defects of existing fixed support claws that require manual adjustment and are prone to workpiece jumping. The support adjustment mechanism is located between the two clamping arms and directly faces the clamping position, forming a three-point envelope support with the clamping arms. This significantly enhances the bending and vibration resistance of slender rod-shaped parts (such as mandrels and shafts). Its adjustability allows for simultaneous control of the workpiece center position and clamping force, achieving a stable effect similar to a hydraulic center frame but with a simpler structure. The overall layout allows the workpiece to maintain coaxiality without frequent adjustments during processing, keeping radial runout and straightness errors at a low level, thereby improving processing accuracy and efficiency while ensuring workpiece integrity.

[0012] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structural principle of this utility model.

[0014] Figure 2 This is a three-dimensional structural diagram of the present invention.

[0015] Figure 3 This is the front view of the present utility model.

[0016] Figure 4 for Figure 3 AA sectional view.

[0017] Explanation of reference numerals in the attached figures: Detailed Implementation

[0018] like Figure 1 As shown in Figure 4, a central frame for fixing rod-shaped parts includes a main frame 1, a support and adjustment mechanism, and two clamping arms 2. The two clamping arms 2 are hinged at their bends to the main frame 1, and the two clamping arms 2 are arranged opposite each other; the front ends of the two clamping arms 2 are used to clamp the workpiece 3 at the clamping station. The support adjustment mechanism is installed on the main frame 1 and is located between the two clamping arms 2; The top of the support adjustment mechanism faces the clamping position.

[0019] In implementation, the main frame 1 is made of cast iron or steel, forming a robust frame structure. The main frame 1 has hinge points for mounting two clamping arms 2. The clamping arms 2 are made of high-strength steel, with a bent middle section designed for each arm. The bent section connects to the hinge point of the main frame 1 via a hinge shaft, allowing the clamping arm 2 to swing around the hinge point. The two clamping arms 2 are arranged opposite each other in a symmetrical layout. The front end of each clamping arm 2 is machined with a V-groove or flat surface for direct contact and clamping of the workpiece 3 located at the clamping station. A support adjustment mechanism is installed at the center of the main frame 1, between the two clamping arms 2. The support adjustment mechanism includes a push rod 6, with its front end serving as the support tip, facing the clamping station. The push rod 6 is connected to an adjusting screw 5 via a threaded drive. The adjusting screw 5 is driven by a rotating unit. When the rotating unit operates, the adjusting screw 5 rotates, pushing the push rod 6 to move linearly, thereby applying a support force to the workpiece 3.

[0020] For example, in a grinding machine scenario, when fixing a shaft-like part whose surface requires fine grinding, the operator first installs the main frame 1 onto the grinding machine worktable to ensure stability. Then, the shaft is placed in the clamping position, and the two clamping arms 2 are manually adjusted so that the front ends of the clamping arms 2 contact the outer cylindrical surface of the shaft from both sides, achieving initial clamping. Subsequently, the rotating unit of the support adjustment mechanism is operated, such as rotating the handle 12, driving the adjusting screw 5 to rotate, causing the push rod 6 to move forward, with the support tip pressing against the center point of the shaft. Through the symmetrical arrangement and hinged design of the clamping arms 2, uniform force is applied to the workpiece 3, avoiding skewing; through the linear and precise control of the support adjustment mechanism, stable support of the central support is achieved, thereby reducing vibration and deformation during the grinding process and improving grinding accuracy and surface finish. The entire device is simple and reliable to operate under the high temperature and high precision requirements of grinding machines, and can be easily implemented by those skilled in the art.

[0021] In one embodiment, each clamping arm 2 has a set screw 4 supporting its rear end. The set screw 4 is mounted on the main frame 1. When the set screw 4 supports forward, the front end of the clamping arm 2 moves toward the clamping position.

[0022] In practice, a set screw 4 is installed near the rear end of each clamping arm 2. The set screw 4 is threaded and is installed in the threaded hole of the main frame 1 through threaded engagement. When the clamping force needs to be adjusted, the operator uses a wrench to rotate the set screw 4, causing the set screw 4 to move forward and press against the rear end of the clamping arm 2. Since the bent part of the clamping arm 2 is hinged to the main frame 1, when the set screw 4 pushes forward, the clamping arm 2 swings around the hinge point, and the front end moves towards the clamping position, thereby pressing the workpiece 3. For example, in grinding, after the shaft is placed in the clamping position, the operator first makes a preliminary adjustment to the clamping arm 2, and then rotates the set screw 4 to make the front end of the clamping arm 2 evenly contact the shaft surface. The fine adjustment of the set screw 4 achieves precise control of the clamping force, avoids the workpiece 3 from slipping or deforming, and improves grinding stability.

[0023] In one embodiment, the support adjustment mechanism includes a rotating unit, a rotating frame 7, an adjusting screw 5, and a top rod 6; The main frame 1 has a limiting guide hole, the push rod 6 is set in the limiting guide hole, and the front end extends out of the limiting guide hole toward the clamping position; the limiting guide hole has the function of preventing the push rod 6 from rotating. The rotating frame 7 is installed at the rear end of the limiting guide hole, and the rotating unit is installed on the rotating frame 7; The rear end of the adjusting screw 5 is connected to the rotating unit via a transmission connection, and the front end of the adjusting screw 5 is connected to the rear end of the push rod 6 via a threaded transmission connection.

[0024] In implementation, a limiting guide hole is machined on the main frame 1. The limiting guide hole is rectangular or keyway shaped, and the push rod 6 is set in the hole, with its front end extending towards the clamping position. The inner wall of the limiting guide hole mates with the push rod 6 to prevent the push rod 6 from rotating, allowing it to move only in a straight line. The rotating frame 7 is fixed to the rear end of the limiting guide hole by bolts, and the rotating unit is mounted on the rotating frame 7. The rear end of the adjusting screw 5 is connected to the rotating unit for transmission, and its front end is threaded to the rear end of the push rod 6. When the rotating unit is driven, the adjusting screw 5 rotates, causing the push rod 6 to move forward or backward through the threaded transmission. For example, in a grinding machine scenario, the operator turns the handle 12, the rotating unit drives the adjusting screw 5 to rotate, and the push rod 6 moves forward in a straight line to press against the axis center. The anti-rotation design of the limiting guide hole achieves precise linear movement of the push rod 6, reducing friction and deviation, and ensuring the reliability of the support.

[0025] In one embodiment, the main frame 1 is further provided with a locking component, which includes a pull rod 8 and a locking handwheel 9. The top rod 6 has an elongated through-hole groove 10. The end of the pull rod 8 passes through the elongated through-hole groove 10 and is threadedly connected to the locking handwheel 9. The head of the pull rod 8 presses on the top rod 6, and the end of the locking handwheel 9 presses on the main frame 1.

[0026] In practice, the push rod 6 has a long through-hole groove 10. The end of the pull rod 8 passes through the long through-hole groove 10 and is then threadedly connected to the locking handwheel 9. The head of the pull rod 8 is designed with an enlarged structure, pressing against the push rod 6, while the end of the locking handwheel 9 presses against the surface of the main frame 1. After the push rod 6 is adjusted to the desired position, the operator rotates the locking handwheel 9, causing the pull rod 8 to press against the push rod 6, thereby fixing the position of the push rod 6. For example, in grinding, after the push rod 6 presses against the center of the shaft, the operator tightens the locking handwheel 9. The cooperation between the pull rod 8 and the long through-hole groove 10 achieves a firm lock on the push rod 6, preventing loosening during processing and improving safety.

[0027] In one embodiment, the outer side of the limiting guide hole is an open structure, and a pressure plate 11 is detachably installed on the open structure.

[0028] In practice, the pressure plate 11 is fixed to the main frame 1 by bolts or a quick-release mechanism, covering the opening. When maintenance or replacement of the push rod 6 is required, the operator can remove the pressure plate 11 and directly remove the push rod 6 from the opening. For example, after the grinding machine has been used, if the push rod 6 is worn and needs to be replaced, the operator can loosen the bolts on the pressure plate 11, remove the pressure plate 11, and easily remove the push rod 6 for replacement. The opening structure and the removable pressure plate 11 enable quick maintenance and reduce downtime.

[0029] In one embodiment, the rotating unit includes a handle 12 and a reducer 13, the input end of the reducer 13 being drivenly connected to the handle 12, and the output end of the reducer 13 being drivenly connected to the adjusting screw 5; the reducer 13 is mounted on the rotating frame 7. In practice, the reducer 13 is mounted on the rotating frame 7 via a bracket. The input end of the reducer 13 is connected to the handle 12, and the output end is connected to the adjusting screw 5. When the operator turns the handle 12, the reducer 13 provides a reduction ratio, causing the adjusting screw 5 to rotate at a lower speed for finer adjustments. For example, in a grinding machine scenario, turning the handle 12 drives the reducer 13, which outputs torque to the adjusting screw 5. The reduction effect of the reducer 13 amplifies the adjusting force and precisely controls the movement, making the movement of the push rod 6 smoother.

[0030] In one embodiment, the output end of the reducer 13 and the adjusting screw 5 are connected by a coupling 14.

[0031] In practice, coupling 14 is either flexible or rigid and is installed between the output shaft of reducer 13 and adjusting screw 5 to compensate for possible installation deviations. For example, in grinding machine operation, coupling 14 allows for certain angular and displacement deviations. The transmission through coupling 14 achieves flexibility and reliability in power transmission and reduces component wear.

[0032] In one embodiment, the front end of the coupling 14 is connected to the adjusting screw 5 via a tapered pin 15; the rear end of the coupling 14 is connected to the output end of the reducer 13 via a flat key 16.

[0033] In implementation, the front end of the coupling 14 is connected to the adjusting screw 5 via a tapered pin 15. The tapered pin 15 is inserted into the tapered holes of the coupling 14 and the adjusting screw 5, providing a secure connection. The rear end of the coupling 14 is connected to the output end of the reducer 13 via a flat key 16, which is embedded in a keyway to transmit torque. For example, in grinding machine applications, the design of the tapered pin 15 and the flat key 16 ensures the alignment and torsional resistance of the transmission. The connection between the tapered pin 15 and the flat key 16 achieves high torque transmission efficiency and avoids slippage.

[0034] In one embodiment, a top block 17 is detachably mounted on the front end of the top rod 6.

[0035] In implementation, a top block 17 is detachably mounted on the front end of the push rod 6. The top block 17 is fixed to the push rod 6 by threads or pins. The top block 17 can be made of different materials or shapes, such as cemented carbide or rubber heads. For example, when grinding shafts of different diameters on a grinding machine, the operator can replace the top block 17 to adapt to the contour of the workpiece 3. The detachable top block 17 realizes the versatility and adaptability of the device and extends its service life.

[0036] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A center frame for fixing rod-shaped parts, characterized in that, Includes the main frame, support adjustment mechanism, and two clamping arms; The two clamping arms are hinged to the main frame at their bends, and the two clamping arms are arranged opposite each other; the front ends of the two clamping arms are used to clamp the workpiece at the clamping station. The support adjustment mechanism is mounted on the main frame and located between the two clamping arms; The top of the support adjustment mechanism faces the clamping position.

2. A center frame for fixing rod-shaped parts according to claim 1, characterized in that, Each of the clamping arms has a set screw at its rear end, which is mounted on the main frame. When the set screw pushes forward, the front end of the clamping arm moves toward the clamping position.

3. A center frame for fixing rod-shaped parts according to claim 1, characterized in that, The support adjustment mechanism includes a rotating unit, a rotating frame, an adjusting screw, and a top rod; The main frame has a limiting guide hole, the push rod is set in the limiting guide hole, and the front end extends out of the limiting guide hole toward the clamping position; the limiting guide hole has the function of preventing the push rod from rotating. The rotating frame is installed at the rear end of the limiting guide hole, and the rotating unit is installed on the rotating frame; The rear end of the adjusting screw is connected to the rotating unit via a transmission connection, and the front end of the adjusting screw is connected to the rear end of the push rod via a threaded transmission connection.

4. A center frame for fixing rod-shaped parts according to claim 3, characterized in that, The main frame is also equipped with a locking component, which includes a pull rod and a locking handwheel. The top rod has a long through-hole groove. The end of the pull rod passes through the long through-hole groove and is threadedly connected to the locking handwheel. The head of the pull rod presses on the top rod, and the end of the locking handwheel presses on the main frame.

5. A center frame for fixing a rod-shaped part according to claim 3 or 4, characterized in that, The outer side of the limiting guide hole is an open structure, and a pressure plate can be detachably installed on the open structure.

6. A center frame for fixing rod-shaped parts according to claim 3, characterized in that, The rotating unit includes a handle and a reducer. The input end of the reducer is connected to the handle, and the output end of the reducer is connected to the adjusting screw. The reducer is mounted on the rotating frame.

7. A center frame for fixing a rod-shaped part according to claim 6, characterized in that, The output end of the reducer and the adjusting screw are connected by a coupling.

8. A center frame for fixing a rod-shaped part according to claim 7, characterized in that, The front end of the coupling is connected to the adjusting screw via a tapered pin; the rear end of the coupling is connected to the output end of the reducer via a flat key.

9. A center frame for fixing rod-shaped parts according to claim 3, characterized in that, A top block is detachably installed at the front end of the top rod.

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