A two-way self-centering clamping device for boring a big end hole of a connecting rod

Abstract

The utility model relates to machining fixture technical field discloses a kind of two-way self-centering clamping devices for connecting rod big head hole boring machining.The device includes base, top block, fixed assembly and clamping assembly.Clamping assembly includes mounting block, motor and internally rotating connection's positive and negative tooth screw rod, screw rod drives two sliding block limited in sliding slot synchronous opposite movement, drives the V-shaped clamping block of top to carry out two-way self-centering clamping to connecting rod big head.Fixed assembly includes support block and the fixed block for being arranged in its top, for supporting connecting rod middle part.V-shaped clamping block and sliding block adopt plug-in quick release structure, and fixed block is realized quick dismounting by hand screwing.The utility model realizes high-precision self-centering by motor drive positive and negative tooth mechanism, without artificial alignment;With quick-release type clamping block and exempt from tool adjustment's support structure, the positioning accuracy, stability and change type efficiency of connecting rod processing are significantly improved.

Description

Technical Field

[0001] This utility model relates to the field of machining fixture technology, and in particular to a bidirectional self-centering clamping device for boring connecting rod big end holes. Background Technology

[0002] Connecting rods are critical transmission components in engines, and the machining accuracy of their big end bores directly affects the engine's assembly quality and operational performance. During the boring process of connecting rod big end bores, the workpiece clamping and positioning are of paramount importance. This requires not only that the fixture firmly locks the workpiece to resist cutting forces, but also that the fixture ensures the center of the hole to be machined strictly coincides with the center of the machine tool spindle. This ensures that the roundness, cylindricity, and positional accuracy of the bored bore meet design standards.

[0003] However, existing connecting rod boring fixtures have certain limitations in practical use. Traditional fixtures mostly employ unidirectional clamping or manually adjustable screw clamping mechanisms. Unidirectional clamping is prone to center misalignment due to fluctuations in the connecting rod blank size, failing to guarantee positioning accuracy. While manual clamping can achieve centering, it heavily relies on the operator's experience and skill, making the alignment process cumbersome and time-consuming, and difficult to guarantee consistency in mass production. Furthermore, connecting rods, as slender rod-shaped parts, are highly susceptible to vibration during machining. Existing general-purpose fixtures often lack effective support for the middle section of the connecting rod, or the support structure is difficult to adjust, making it difficult to adapt to the rapid changeover requirements of connecting rods of different specifications. This results in long production preparation cycles and low overall machining efficiency.

[0004] Therefore, this utility model proposes a bidirectional self-centering clamping device for boring connecting rod big end holes to overcome the shortcomings of the prior art. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a bidirectional self-centering clamping device for boring connecting rod big end holes, aiming to improve the problems of insufficient centering accuracy of connecting rod machining fixtures in the prior art, as well as the cumbersome and time-consuming operation of changing clamping and support components for connecting rods of different specifications, resulting in low production efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a bidirectional self-centering clamping device for boring a connecting rod big end hole, comprising: a base, and a top block fixedly connected to one end of the top surface of the base; a fixing component disposed in the middle of the top surface of the base, and a clamping component disposed on the top surface of the base away from the top block.

[0007] The clamping assembly has a unique driving and transmission structure, including a mounting block fixedly connected to the top surface of the base. The top surface of the mounting block has a groove along its length. A threaded rod is rotatably connected inside the mounting block. A motor is fixedly connected to one end of the mounting block. The output end of the motor is drivenly connected to the end of the threaded rod. The threaded rod has two sections of threads with opposite directions of rotation. Two symmetrically distributed sliding blocks are threadedly connected to the surface of the threaded rod. The bottom ends of the two sliding blocks are slidably engaged inside the groove. A V-shaped clamping block is connected to the top of each sliding block.

[0008] Furthermore, the fixing component, the base, and the top block are combined through a specific positional distribution. The fixing component includes a support block fixedly connected to the top surface of the base, and a fixing block disposed on the top of the support block.

[0009] Preferably, the V-shaped clamping block and the sliding block are detachably connected. The bottom of the V-shaped clamping block is fixedly connected to an insert block, and the top of the sliding block has a slot that matches the shape of the insert block. The insert block is inserted into the slot.

[0010] Preferably, the sliding block sidewall is threaded with a fixing screw, the end of the fixing screw passing through the sliding block sidewall and abutting against the insert block sidewall, for locking and fixing the clamping block.

[0011] Preferably, a rubber pad is fixedly connected to the center of the top surface of the mounting block. The rubber pad is located between the two sliding blocks, and the height of the top surface of the rubber pad is lower than the height of the bottom end of the V-groove of the V-shaped clamping block, so as to play a buffering and protective role.

[0012] Preferably, the top of the support block is provided with an installation groove, and both ends of the fixing block are fixedly connected with installation plates, with the two installation plates respectively snapped into the inside of the two ends of the installation groove.

[0013] Preferably, the side wall of the support block is threaded with a hand screw, the end of which passes through the side wall of the support block and abuts against the side wall of the mounting plate, so as to enable quick manual assembly and disassembly of the support assembly.

[0014] Preferably, the top block has a positioning plane on one side facing the fixing component, the V-shaped openings of the two V-shaped clamping blocks are arranged opposite each other, and the central axis formed by the two V-shaped clamping blocks, the center line of the top of the fixing block and the center of the top block are in the same vertical plane to ensure accurate positioning during processing.

[0015] This utility model has the following beneficial effects:

[0016] 1. This utility model solves the problems of low clamping and positioning accuracy of connecting rod big end and long time consumption of manual alignment in the prior art by setting a structure in which the motor drives the positive and negative threaded rod to drive two sliding blocks and V-shaped clamping blocks to move synchronously in opposite directions. It achieves the effect of high-precision bidirectional self-centering clamping without manual assistance, effectively ensuring the center positioning accuracy of connecting rod boring.

[0017] 2. This utility model solves the problem of cumbersome disassembly and assembly and poor versatility of existing fixtures when changing different specifications of chucks by setting an insert block at the bottom of the V-shaped clamping block to cooperate with the slot at the top of the sliding block and combining it with a detachable connection structure that is locked by side fixing screws. It achieves the effect of being able to quickly change the clamping parts to adapt to different diameter connecting rod big ends and significantly shorten the production changeover time. Attached Figure Description

[0018] Figure 1 This is a perspective view of a bidirectional self-centering clamping device for boring the big end hole of a connecting rod according to the present invention;

[0019] Figure 2 This is a schematic diagram of the mounting block of a bidirectional self-centering clamping device for boring the big end hole of a connecting rod, as proposed in this utility model.

[0020] Figure 3 This is a schematic diagram of the sliding block of a bidirectional self-centering clamping device for boring the big end hole of a connecting rod according to the present invention;

[0021] Figure 4 This is a schematic diagram of the support block of a bidirectional self-centering clamping device for boring the big end hole of a connecting rod, as proposed in this utility model.

[0022] Legend:

[0023] 1. Base; 2. Top block; 3. Clamping assembly; 301. Mounting block; 302. Threaded rod; 303. Motor; 304. Rubber pad; 305. Sliding block; 306. Slide groove; 307. V-shaped clamping block; 308. Insert block; 309. Slot; 310. Fixing screw; 4. Fixing assembly; 401. Support block; 402. Fixing block; 403. Mounting plate; 404. Mounting groove; 405. Tightening screw. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Reference Figures 1-4 The present invention provides an embodiment of a bidirectional self-centering clamping device for boring a connecting rod large end hole, comprising a base 1 and a top block 2 fixedly connected to one end of the top surface of the base 1. The base 1 serves as a load-bearing mounting platform for the entire device, providing a stable support foundation for each component. The top block 2 is fixedly disposed at one end of the base 1 and is mainly used to abut against the small end or non-machined end of the connecting rod to be machined, thereby providing an accurate axial positioning reference for the connecting rod.

[0026] On the top surface of the base 1, in addition to the top block 2 at one end, a clamping component 3 is provided at the other end of the top surface of the base 1 away from the top block 2. A fixing component 4 is provided in the area between the top block 2 and the clamping component 3 on the top surface of the base 1. With this layout, the top block 2, the fixing component 4 and the clamping component 3 are distributed in sequence along the length of the base 1, corresponding to the end, middle part and large end of the connecting rod respectively, forming a complete multi-point positioning and clamping system.

[0027] To achieve high-precision bidirectional self-centering clamping of the big end of the connecting rod, the clamping assembly 3 includes a mounting block 301 fixedly connected to the top surface of the base 1. The mounting block 301 serves as the core carrier for power transmission and guidance. A groove 306 is formed on its top surface along the length direction. The groove 306 mainly serves as a guide and limiter. A threaded rod 302 is rotatably connected to the inside of the mounting block 301 through a bearing. The threaded rod 302 extends along the length direction of the groove 306. To drive the threaded rod 302 to rotate, a motor 303 is fixedly connected to one end of the outer wall of the mounting block 301 by bolts. The output shaft of the motor 303 passes through the side wall of the mounting block 301 and is connected to one end of the threaded rod 302 for transmission. When the motor 303 starts, it can drive the threaded rod 302 to rotate smoothly inside the mounting block 301.

[0028] Furthermore, the threaded rod 302 has two sections of threads with opposite directions of rotation, one left-handed and the other right-handed. Two symmetrically distributed sliding blocks 305 are connected to the threaded drive on the surface of the threaded rod 302. The two sliding blocks 305 are located in the two sections of threads with opposite directions of rotation. Notably, the bottom ends of both sliding blocks 305 are slidably engaged with the grooves 306 on the top of the mounting block 301. The bottom ends of the sliding blocks 305 extend into the grooves 306 and maintain threaded engagement with the threaded rod 302. The grooves 306 restrict the movement of the sliding blocks 305 with the threaded rod 302. The degree of freedom of rotation of the threaded rod 302 allows the rotational motion of the threaded rod 302 to be converted into linear reciprocating motion of the two sliding blocks 305 along the direction of the groove 306. Since the threads rotate in opposite directions, the two sliding blocks 305 will move synchronously towards each other or synchronously away from each other, thereby achieving a self-centering function. A V-shaped clamping block 307 is connected to the top of each sliding block 305 through a connecting structure. The V-shaped clamping block 307 moves synchronously with the sliding block 305. The relative motion of the two V-shaped clamping blocks 307 is used to clamp and center the cylindrical surface of the big end of the connecting rod.

[0029] In addition, in order to protect the workpiece and provide a buffering effect, a rubber pad 304 is fixedly connected to the middle of the top surface of the mounting block 301. The rubber pad 304 is located between the two sliding blocks 305, and the height of the top surface of the rubber pad 304 is lower than the height of the bottom end of the V-groove of the V-shaped clamping block 307. This ensures that the big end face of the connecting rod can contact the rubber pad 304 to generate a buffer during the clamping process, while not interfering with the clamping action of the V-shaped clamping block 307 on the side of the connecting rod.

[0030] The V-shaped clamping block 307 is a key actuator that directly contacts the cylindrical surface of the workpiece. A plug block 308 is fixedly connected to the bottom of the V-shaped clamping block 307. The plug block 308 has a regular geometric shape to facilitate positioning. At the same time, the sliding block 305 has a slot 309 on its top surface that is adapted to the shape and size of the plug block 308. The slot 309 is recessed downward and has sufficient depth to provide stable support.

[0031] In the assembled state, the V-shaped clamp 307 is vertically inserted into the slot 309 at the top of the sliding block 305 via the bottom insert 308. The engagement of the insert 308 and the slot 309 achieves the initial horizontal positioning of the V-shaped clamp 307. To ensure the stability of the connection and prevent loosening during processing, the side wall of the sliding block 305 has a through hole and a threaded fixing screw 310. The end of the fixing screw 310 passes through the side wall of the sliding block 305 and extends into the slot 309, finally pressing against the side wall surface of the insert 308. By tightening the fixing screw 310, the axial thrust generated by the thread presses the insert 308 tightly against the inner wall of the slot 309, thereby achieving a rigid fixed connection between the V-shaped clamp 307 and the sliding block 305. This structural design allows the operator to simply loosen the fixing screw 310 to pull out the insert 308, thus quickly replacing different specifications of the V-shaped clamp 307, greatly improving the changeover efficiency.

[0032] To ensure overall machining accuracy, the side of the top block 2 facing the fixed component 4 is machined with a positioning plane as an axial reference. The V-shaped openings of the two V-shaped clamping blocks 307 are set opposite each other. After assembly, the central axis formed by the two V-shaped clamping blocks 307 is in the same vertical plane as the center of the top block 2, ensuring that the center line of the connecting rod coincides with the center of the machine tool spindle when it is clamped, thus achieving precise self-centering clamping.

[0033] Based on the above embodiments, in order to achieve rapid adjustment of the height or shape of the mid-section support for different models of connecting rods, the fixing component 4 adopts a modular quick-release structure design. Please refer to... Figure 1 and Figure 4 The fixing component 4 includes a support block 401 fixedly connected to the middle of the top surface of the base 1. The support block 401 serves as the base of the support system. An installation groove 404 is provided on the top of the support block 401. The installation groove 404 has a defined shape and depth to accommodate the mating parts. A fixing block 402 is used to cooperate with the support block 401. The fixing block 402 is directly used to support the rod body of the connecting rod. Both ends of the fixing block 402 are fixedly connected to the mounting plates 403 by welding or integral molding. The two mounting plates 403 are respectively snapped into the two ends of the mounting groove 404 on the top of the support block 401. The initial positioning of the fixing block 402 on the horizontal plane is achieved by the shape matching of the mounting plates 403 and the mounting groove 404.

[0034] To securely lock the fixing block 402 onto the support block 401 and allow for manual operation, the support block 401 has a threaded hole on its side wall and a hand screw 405 is threadedly connected thereto. The end of the hand screw 405 passes through the side wall of the support block 401 and extends into the area of ​​the mounting groove 404, eventually pressing against the side wall surface of the mounting plate 403. When the hand screw 405 is tightened, the resulting lateral pressure presses the mounting plate 403 against the inner wall of the mounting groove 404, thus completing the rigid connection of the fixing block 402. When it is necessary to replace the fixing block 402 with one of different height or shape, the operator only needs to loosen the hand screw 405 to remove the fixing block 402 together with the mounting plate 403 without the need for additional tools such as wrenches.

[0035] Working principle: When clamping before processing the connecting rod, the operator places the connecting rod to be processed on the base 1, so that one end or the small end of the connecting rod rests on the positioning plane of the top block 2, the middle part of the connecting rod is placed on the fixing block 402 of the fixing component 4, and the large end of the connecting rod is placed between the two V-shaped clamping blocks 307 of the clamping component 3.

[0036] Then, the motor 303 is started. The output shaft of the motor 303 rotates, causing the threaded rod 302 to rotate inside the mounting block 301. Since the threaded rod 302 has two sections of threads with opposite directions of rotation, the two sliding blocks 305 threadedly connected to the threaded rod 302 begin to move synchronously in opposite directions along the sliding groove 306 under the guidance and restriction of the sliding groove 306. The sliding blocks 305 drive the top V-shaped clamping block 307 to move closer synchronously, thereby performing bidirectional self-centering clamping on the cylindrical surface of the connecting rod big end. During the clamping process, the rubber pad 304 located between the two sliding blocks 305 plays a buffering and supporting role on the end face of the connecting rod big end.

[0037] During processing, the fixing component 4 provides stable support to the middle of the connecting rod through the fixing block 402, effectively preventing vibration or deformation of the rod body caused by cutting force. When it is necessary to replace the connecting rod with a different specification for processing, for changes in the big end size of the connecting rod, the operator loosens the fixing screw 310, pulls the insert 308 at the bottom of the V-shaped clamp 307 out of the slot 309 at the top of the sliding block 305, replaces the new V-shaped clamp 307 with a suitable one, and tightens it in the reverse direction. For changes in the height or shape of the connecting rod body, the operator loosens the hand screw 405 by hand, removes the fixing block 402 along with the mounting plate 403 from the mounting slot 404 of the support block 401, quickly replaces the new fixing block 402 with a suitable one, and tightens the hand screw 405 to complete the fixation, thereby achieving efficient production changeover.

Claims

1. A bidirectional self-centering clamping device for boring a connecting rod big end hole, comprising a base (1) and a top block (2) fixedly connected to one end of the top surface of the base (1); Its features are, The base (1) has a fixing component (4) in the middle of its top surface, and a clamping component (3) is provided at the end of the top surface of the base (1) away from the top block (2). The clamping assembly (3) includes a mounting block (301) fixedly connected to the top surface of the base (1). The top surface of the mounting block (301) is provided with a sliding groove (306) along the length direction. A threaded rod (302) is rotatably connected inside the mounting block (301). A motor (303) is fixedly connected to one end of the mounting block (301). The output end of the motor (303) is connected to the end of the threaded rod (302). The threaded rod (302) has two sections of threads with opposite directions of rotation. Two symmetrically distributed sliding blocks (305) are threadedly connected to the surface of the threaded rod (302). The bottom ends of the two sliding blocks (305) are slidably engaged inside the sliding groove (306). A V-shaped clamping block (307) is connected to the top of each sliding block (305). The fixing component (4) includes a support block (401) fixedly connected to the top surface of the base (1) and a fixing block (402) disposed on the top of the support block (401).

2. The bidirectional self-centering clamping device for boring the big end hole of a connecting rod according to claim 1, characterized in that, The V-shaped clamp (307) and the sliding block (305) are detachably connected. The bottom of the V-shaped clamp (307) is fixedly connected to the insert (308). The top of the sliding block (305) is provided with a slot (309) that matches the shape of the insert (308). The insert (308) is inserted into the slot (309).

3. The bidirectional self-centering clamping device for boring the connecting rod big end hole according to claim 2, characterized in that, The sliding block (305) has a screw (310) threadedly connected to its side wall. The end of the screw (310) passes through the side wall of the sliding block (305) and abuts against the side wall of the insert block (308).

4. The bidirectional self-centering clamping device for boring the big end hole of a connecting rod according to claim 1, characterized in that, A rubber pad (304) is fixedly connected to the middle of the top surface of the mounting block (301). The rubber pad (304) is located between two sliding blocks (305), and the height of the top surface of the rubber pad (304) is lower than the height of the bottom of the V-groove of the V-shaped clamping block (307).

5. The bidirectional self-centering clamping device for boring the big end hole of a connecting rod according to claim 1, characterized in that, The support block (401) has an installation groove (404) on its top, and the fixing block (402) has a mounting plate (403) fixedly connected to both ends. The two mounting plates (403) are respectively snapped into the inside of the two ends of the mounting groove (404).

6. The bidirectional self-centering clamping device for boring the connecting rod big end hole according to claim 5, characterized in that, The support block (401) has a threaded connection to a hand screw (405) on its side wall. The end of the hand screw (405) passes through the side wall of the support block (401) and abuts against the side wall of the mounting plate (403).

7. The bidirectional self-centering clamping device for boring the connecting rod big end hole according to claim 1, characterized in that, The top block (2) has a positioning plane on one side facing the fixing component (4), the V-shaped openings of the two V-shaped clamps (307) are arranged opposite each other, and the central axis formed by the two V-shaped clamps (307), the top center line of the fixing block (402) and the center of the top block (2) are in the same vertical plane.

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