Hydraulic automatic centering and clamping mechanism for crankshaft

Abstract

The utility model discloses a crankshaft hydraulic automatic centering clamping mechanism which comprises a bottom plate, an oil cylinder and V-shaped iron are installed on the upper plane of the bottom plate, and the lower plane of the bottom plate is fixed to a workbench of a large numerical control planer type milling machine. The V-shaped iron is provided with an up-down slide way which is internally provided with a driven rack and a driving rack respectively; a middle transition gear is arranged between the driving rack and the driven rack and is meshed with the driving rack and the driven rack; the oil cylinder is connected with the left end of the driving rack; a lever structure is arranged at the right end of the driving rack, the lever structure is connected with a parallel four-bar mechanism and is arranged on an inclined surface of a movable pressing plate of a parallelogram structure, and the same lever structure and parallel four-bar mechanism are arranged at the left end of the driven rack; the utility model has the advantages that the crankshaft is positioned and clamped on the V-shaped iron at one time, so that the clamping stability of the crankshaft is improved, and the production efficiency is greatly improved. And it is guaranteed that the machining precision of the plane needed for milling and installing the balancing weight on the crank arm of the crankshaft meets the drawing requirement.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of machining, specifically relates to a crankshaft hydraulic automatic centering clamping mechanism. BACKGROUND

[0002] Large crankshaft blank is manufactured by using the drop forging extrusion process instead of the die forging and forging process, and the blank allowance is very uneven. In the machining process, the uneven blank allowance and asymmetric shape inevitably lead to machining error, which causes the center of gravity to deviate from the rotation center, resulting in engine vibration and vibration force, causing engine noise and vibration. With the increase of the rotation speed of the crankshaft, the vibration caused by dynamic imbalance becomes more intense. Therefore, the crankshaft has a high-precision plane milled on the crank arm, and a threaded hole is processed for installing the balance weight block for dynamic balance of the crankshaft. In the machining process, the crankshaft is dynamically balanced, and holes are drilled in the balance weight block to remove weight, so as to ensure the dynamic balance of the crankshaft. If the shape tolerance and position tolerance of the balance weight block installation plane milled on the crank arm do not meet the processing requirements of the drawing, the installation accuracy of the balance weight block on the crank arm will be affected, the pre-tightening force of the balance weight block mounting bolt will be affected, the overall dynamic balance of the crankshaft will be out of tolerance, and the dynamic balance index of the engine cannot be ensured. The existing processing technology for milling the high-precision plane on the crank arm is line marking processing.

[0003] According to the existing technology, the line marking and clamping operation is complex, time-consuming and laborious, and is greatly affected by human factors. Frequent movement of the crankshaft can cause scratches, the production efficiency is low, the labor intensity of the operator is high, the surface shape tolerance and position tolerance of the milled plane are poor, and even there is an out-of-tolerance phenomenon. This line marking processing method is only suitable for single-piece and small-batch production. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims to provide a large-scale crankshaft hydraulic automatic centering clamping mechanism to reduce the machining time of the crankshaft and the balance weight block installation plane milled on the crank arm, realize automatic production line processing, improve the size and surface shape tolerance and position tolerance machining precision of the milled plane on the crank arm, and improve the production efficiency.

[0005] The specific technical scheme is as follows:

[0006] The utility model discloses a hydraulic automatic centering and clamping mechanism of crankshaft, including bottom plate, the oil cylinder is installed with V -shaped iron on the bottom plate plane, and the bottom plate lower plane is fixed with large numerical control planer -type milling machine work table, the oil cylinder is connected with the left end of the driving rack on V -shaped iron through threaded connecting rod, be provided with the passive rack and driving rack in the up and down slide way on V -shaped iron, be provided with intermediate transition gear between the driving rack and passive rack, and the intermediate transition gear is engaged with driving rack and passive rack, and the left end of oil cylinder is connected with driving rack, and the right end of driving rack is provided with lever structure, and the lever structure is connected with parallelogram mechanism, and the slope of parallelogram structure is equipped with movable presser plate, and the quenching pad block installed on the slope through screw is abutted with workpiece,

[0007] The lever structure includes a rotating plate, one end of the connecting plate is connected with the rotating plate, and the other end of the connecting plate is fixed on the right end of the driving rack.

[0008] The parallelogram mechanism includes a rotating plate, a movable presser plate, a supporting plate and a V-shaped iron.

[0009] The rotating plate is connected with the movable presser plate and the V-shaped iron, the lower end of the supporting plate is connected with the V-shaped iron, and the upper end is connected with the movable presser plate; the end of the movable presser plate is a slope, and the quenching pad block installed on the slope through screw is abutted with the workpiece.

[0010] The left end of the passive rack is provided with the same lever structure and parallelogram mechanism.

[0011] The bottom plate lower plane is connected with the large numerical control planer -type milling machine work table through T -shaped nut and positioning key.

[0012] The tooth surface of the driving rack and the passive rack is designed with a keyway on one side of the opposite direction cylindrical surface, and the circumferential direction is limited by the cylindrical positioning pin.

[0013] The utility model has the advantages of:

[0014] 1. The clamping operation is simple, the production efficiency is effectively improved, and automatic processing can be realized on the production line.

[0015] 2. The two symmetrical presser plates arranged above the V-shaped iron synchronously clamp the crankshaft, the positioning and clamping are completed at one time on the V-shaped iron, the stability of the crankshaft clamping is improved, the vibration of the crankshaft under the action of the strong milling force during milling is prevented, and the machining precision of the plane required for milling and installing the counterweight block on the crank arm of the marine crankshaft is ensured.

[0016] 3. The two synchronous movable presser plates are located below the outer circle main shaft diameter to be clamped in the thickness direction through ingenious design, are lower than the milled plane on the crank arm, the disc milling cutter of the machine tool can smoothly pass, and the presser plates do not need to be disassembled and assembled again to avoid the disc milling cutter of the machine tool.

[0017] 4. The utility model discloses a hydraulic drive, through the piston rod of hydraulic cylinder, drive rack and pinion mechanism moves, passes through lever mechanism and parallel four bar mechanism again, the synthesis of three kinds of mechanisms, completes the force clamping function of crankshaft.

[0018] 5. The utility model discloses compact structure is an independent unit, can use alone also, can use simultaneously with multiple, and good versatility can be applicable to the positioning and clamping of different crankshaft products.

[0019] 6. The utility model discloses in the use process, does not need artificial alignment positioning and uses spanner clamping pressboard, alleviates the labor intensity of staff. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the structural diagram of the utility model;

[0021] Figure 2 It is Figure 1 Cutaway view in the drawing;

[0022] Figure 3 It is Figure 1 B-B view in the drawing;

[0023] Figure 4 It is Figure 1 C-C view in the drawing;

[0024] Figure 5 It is Figure 1 D-D view in the drawing;

[0025] Figure 6 It is Figure 1 E-E view in the drawing;

[0026] Figure 7 It is Figure 1 F-F view in the drawing;

[0027] Figure 8 It is Figure 1 G-G view in the drawing;

[0028] Figure 9 It is Figure 1 H-H view in the drawing;

[0029] In the figure: 1 - base plate, 2 - pad, 3 - oil cylinder, 4 - bolt, 5 - threaded connecting rod, 6 - left connecting bracket, 7 - driving rack, 8 - passive rack, 9 - V-shaped iron, 10 - positioning key one, 11 - positioning key two, 12 - gear shaft, 13 - bearing, 14 - T-shaped nut, 15 - large numerical control gantry milling workbench, 16 - connecting rod, 17 - pin shaft one, 18 - locking rod, 19 - nut one, 20 - connecting plate, 21 - nut two, 22 - right connecting bracket, 23 - rotating plate, 24 - pin shaft two, 25 - moving pressing plate, 26 - supporting plate, 27 - pin shaft three, 28 - quenching positioning block, 29 - quenching pad, 30 - adjusting pad, 31 - wear-resistant bushing, 32 - cylindrical positioning pin one, 33 - cylindrical positioning pin two, 34 - intermediate transition gear, 35 - key, 36 - spacer. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0031] As Figures 1-9As shown, the marine crankshaft automatic centering hydraulic clamping mechanism, including the base plate 1, the pad 2, the oil cylinder 3, the bolt 4, the threaded connecting rod 5, the left connecting bracket 6, the driving rack 7, the passive rack 8, the V-shaped iron 9, the positioning key one 10, the positioning key two 11, the gear shaft 12, the bearing 13, the T-shaped nut 14, the large CNC gantry milling workbench 15, the connecting rod 16, the pin shaft one 17, the locking rod 18, the nut one 19, the connecting plate 20, the nut two 21, the right connecting bracket 22, the rotating plate 23, the pin shaft two 24, the moving pressing plate 25, the supporting plate 26, the pin shaft three 27, the quenching positioning block 28, the quenching pad 29, the adjusting pad 30, the wear-resistant bushing 31, the cylindrical positioning key one 32, the cylindrical positioning key two 33, the intermediate transition gear 34, the key 35, the spacer 36. The lower plane of the base plate 1 is provided with the T-shaped nut 14 and the positioning key two 11, and is connected to the upper surface of the large CNC gantry milling workbench 15 through screws. The upper plane of the base plate 1 is provided with the pad 2 and the oil cylinder 3, and the V-shaped iron 9 and the positioning key one 10. The pad 2 and the oil cylinder 3 are connected and fixed through the bolt 4, and the V-shaped iron 9 and the positioning key one 10 are connected through screws. The oil cylinder 3 is connected with the left U-shaped slot hole of the driving rack 7 on the V-shaped iron 9 through the piston rod and the threaded connecting rod 5. The driving rack 7 is connected with the key 35, the gear shaft 12, the spacer 36, the bearing 13 and the passive rack 8 through the intermediate transition gear 34. The V-shaped iron has two parallel stepped inner holes, two vertical pin holes communicating with the stepped inner holes and a U-shaped slot hole in the vertical V-shaped iron bottom surface direction. The two stepped holes are divided into two regions, the hole near the V-shaped iron bottom plane side is 9a and 9b coaxial hole diameters. The upper hole parallel to it is 9c and 9d coaxial hole diameters. Four holes are provided with wear-resistant bushings 31. The wear-resistant bushing holes near the V-shaped iron bottom plane side are 31a and 31b coaxial hole diameters, and the wear-resistant bushing holes parallel to them on the upper side are 31c and 31d coaxial hole diameters. The two vertical pin holes communicating with the stepped inner holes are 9k near the V-shaped iron on the upper side and 9h on the V-shaped iron bottom surface on the lower side. The U-shaped slot hole is 9e. There is a through hole perpendicular to the U-shaped slot hole, and 9f and 9g coaxial hole diameters are designed on the two sides of the U-shaped slot hole. The driving rack 7 is installed in the wear-resistant bushing 31a and 31b coaxial hole diameters, and is circumferentially positioned by the cylindrical positioning pin one 32 installed in the V-shaped iron 9h hole. The passive rack 8 is installed in the wear-resistant bushing 31c and 31d coaxial hole diameters, and is circumferentially positioned by the cylindrical positioning pin one 33. The intermediate transition gear 34, the key 35, the gear shaft 12 and the spacer 36 are supported and installed in the V-shaped iron through the bearing 13. The intermediate transition gear 34 is adjusted by the spacer 36 to ensure that it is located in the middle position of the U-shaped slot 9e hole, and the bearing 13 is installed in the two side holes 9f and 9g of the U-shaped slot to support the gear shaft 12.The driving rack 7 is indirectly engaged with the passive rack 8 through the intermediate transition gear 34 installed in the U-shaped slot 9e, forming a gear rack mechanism. The two ends of the gear shaft 12 and the inner hole of the bearing 13 are fixed together by a shaft elastic retainer, while the outer diameter of the bearing 13 is installed in the coaxial holes of the U-shaped slots 9f and 9g on both sides of the V-shaped iron 9 through a hole elastic retainer. The positioning hole on the left end of the connecting rod 16 is connected with the positioning shaft on the right end of the driving rack 7, while the positioning shaft on the right end is connected with the positioning hole of the connecting plate 20, which is fixed together by the locking rod 18 and the nut 19. The lower part of the rotating plate 23 has a hollow long slot on one end, which is connected with the right connecting bracket 22 through the pin shaft 17 inserted into the hole, and is fixed on the connecting plate 20 by the nut 21. The other end of the upper part of the rotating plate 23 is connected with the one end of the supporting plate 26 through the pin shaft 24, the moving pressing plate 25 and the pin shaft 27. The middle part of the rotating plate 23 is connected with the upper part of the V-shaped iron 9 through the pin shaft 24. The other end of the supporting plate 26 is also connected with the upper part of the V-shaped iron 9 through the pin shaft 27, and the installation positions of the pin shaft 24 and the pin shaft 27 on the V-shaped iron 9 are on the same horizontal line. The parallelogram formed by the two pin shafts 24 and the two pin shafts 27 needs to maintain equal distance between each pair of opposite sides. The right end of the passive rack 8 is not connected with other parts, but has a keyway on the side of the opposite cylindrical surface of the rack tooth surface, which is limited in the circumferential direction by the cylindrical positioning pin 33 installed in the hole of the V-shaped iron 9k, and the left end is connected with the left connecting bracket 6 and the pin shaft 17 on the lower part of the rotating plate 23 through the adjusting pad 30. The other end of the upper part of the rotating plate 23 is also connected with the one end of the supporting plate 26 through the pin shaft 24, the moving pressing plate 25 and the pin shaft 27. The middle part of the rotating plate 23 is connected with the upper part of the V-shaped iron 9 through the pin shaft 24. The other end of the supporting plate 26 is also connected with the upper part of the V-shaped iron 9 through the pin shaft 27, and the installation positions of the pin shaft 24 and the pin shaft 27 on the V-shaped iron 9 are on the same horizontal line. The parallelogram formed by the two pin shafts 24 and the two pin shafts 27 needs to maintain equal distance between each pair of opposite sides. The upper part of the V-shaped iron 9 is installed with two sets of parallelogram mechanisms, which form four-bar parts of the same size and are symmetrical after installation. The two parallelogram mechanisms drive two moving pressing plates to move synchronously, clamping or loosening. On the V-shaped surface of the V-shaped iron 9, a quenching positioning block 28 is installed through a screw, which is a cubic-shaped part with high-precision matched and ground upper and lower surfaces that are parallel to each other.

[0032] The left end of the threaded connecting rod 5 is a threaded hole, the right end is a journal with a concave annular groove, and the outer end surface is a ball head surface structure. The left side of the driving rack 7 is connected with the right end of the threaded connecting rod 5. The right side is connected with one end of the connecting rod 16, which is designed with a protruding positioning shaft. The side of the tooth surface of the rack is also designed with a key groove, which is limited in the circumferential direction by using a cylindrical positioning pin 32. The left side of the connecting rod 16 is connected with one end of the driving rack 7, which is designed with a positioning hole. The right side is a protruding positioning shaft connected with the connecting plate 20. The center of the connecting rod 16 is a through hole, and the locking rod 18 passes through the hole to lock and fix the driving rack 7 and the connecting rod 16 together.

[0033] The use method of the utility model is:

[0034] 1. Adjust the function of each component of the hydraulic system to check whether it is normal, whether the system pressure meets the working pressure required by the hydraulic cylinder, and ensure that the clamping force is reliable when the hydraulic cylinder works.

[0035] 2. Check whether the gear and rack meshing is reliable, whether the action is flexible, and whether the synchronization error and moving distance meet the requirements.

[0036] 3. Check whether the lever mechanism rotates with jamming phenomenon, especially the hollow long hole at the lower part of the rotating plate 24, whether it can meet the travel requirement of the lever rotation.

[0037] 4. Check whether the moving distance of the moving pressure plate 25 in the parallel four-bar mechanism can meet the design requirement, whether the four-bar mechanism has jamming phenomenon, whether the action is flexible, and ensure that the clamping travel meets the clamping requirement.

[0038] 5. Check the coaxiality of the V-shaped center line composed of two quenching positioning blocks 28 on the same V-shaped iron and the V-shaped center line composed of two quenching positioning blocks 28 on the other two or three V-shaped irons

[0039] 6. According to the operation specification, carry out pressure test, and carry out positioning and clamping test according to the process requirement.

[0040] 7. Wipe the upper surface of the two quenching positioning blocks 28 on the V-shaped iron, the surface of the two quenching blocks 29 installed on the inclined surface through the screw, and the surface of the positioning block for the crank pin, the surface of the crank pin shaft neck, and the surface of the crank pin shaft neck.

[0041] 8. The main shaft neck for positioning the crankshaft at both ends is placed on the two quenching positioning blocks 28 of the V-shaped iron in the ship crankshaft hydraulic automatic centering and clamping mechanism which has been debugged. The crank pin shaft neck for positioning is rotated to the horizontal position for circumferential positioning. The rotation of the crankshaft can be carried out by using a numerical control rotary workbench, or manually.

[0042] 9. The machine tool and hydraulic system are started, the hydraulic cylinder piston moves, the gear rack mechanism moves, the lever mechanism starts to rotate, the parallel four-bar mechanism moves the pressing plate 25 to translate, the positioning and clamping of the positioning main shaft neck of the crankshaft are started, the machine tool main shaft is moved, the milling cutter is aligned, and the milling process is started.

Claims

1. A crankshaft hydraulic automatic centering clamping mechanism, comprising a base plate, an upper surface of which is mounted an oil cylinder and a V-shaped iron, and a lower surface of which is fixed to a workbench of a large CNC gantry milling machine; characterized in that: The oil cylinder is connected to the left end of the active rack on the V-shaped iron through a threaded connecting rod. The V-shaped iron is provided with upper and lower slideways, and the upper and lower slideways are respectively provided with a passive rack and an active rack; an intermediate transition gear is provided between the active rack and the passive rack, and the intermediate transition gear is meshed with the active rack and the passive rack; the oil cylinder is connected to the left end of the active rack; a lever structure is provided at the right end of the active rack, and the lever structure is connected to a parallelogram mechanism. A movable pressure plate is provided on the inclined surface of the parallelogram structure, and a quenching pad mounted on the inclined surface by screws abuts against the workpiece; The lever structure includes a rotating plate, the rotating plate is axially connected to one end of the connecting plate, and the other end of the connecting plate is fixed to the right end of the active rack; The parallel four-bar mechanism includes a rotating plate, a movable pressure plate, a supporting plate and a V-shaped iron; The rotating plate is connected to the movable pressing plate and the V-shaped iron shaft respectively. The lower end of the supporting plate is connected to the V-shaped iron shaft, and the upper end is connected to the movable pressing plate. The end of the movable pressing plate is on an inclined surface, and a quenching pad installed on the inclined surface by screws abuts against the workpiece. The left end of the passive rack is provided with the same lever structure and parallel four-bar mechanism.

2. The crankshaft hydraulic automatic centering clamping mechanism according to claim 1, characterized in that: The lower plane of the base plate is connected to the worktable of a large CNC gantry milling machine through T-shaped nuts and locating keys.

3. The crankshaft hydraulic automatic centering clamping mechanism according to claim 1, characterized in that: The cylindrical surfaces of the active rack and the passive rack in the opposite direction of the tooth surface are respectively designed with key grooves, and are limited in the circumferential direction by cylindrical positioning pins.

4. The crankshaft hydraulic automatic centering clamping mechanism according to claim 1, characterized in that: A quenching positioning block is mounted on the end of the movable pressing plate via screws.

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