Fixture for machining large and small holes of engine connecting rod

Abstract

In order to solve the problems of unstable clamping, complicated clamp structure, complicated clamping operation and the like in the engine connecting rod large and small hole machining method in the prior art, the utility model provides a large and small hole machining clamp for an engine connecting rod. The device comprises a bottom plate, a fixed plate, a movable plate, a guide bolt, a spring, a fixed cam, a movable cam, a fixed seat, a rocker, a connecting rod, a clamping air cylinder, a material pushing guide seat, a material pushing plate and a material pushing air cylinder. The bottom plate is a rectangular plate; the fixed plate and the movable plate are both rectangular plates and are oppositely, transversely and vertically arranged on the left side of the front middle portion of the bottom plate. Positioning concave steps are arranged on the opposite faces of the fixed plate and the movable plate in a mirror symmetry mode, and a clamping cavity is formed by the opposite positioning concave steps and a gap between the fixed plate and the movable plate. The large and small hole machining clamp for the engine connecting rod has the advantages that a connecting rod blank can be accurately positioned, and clamping is stable; the structure is simple, and operation is easy and convenient.

Description

Technical Field

[0001] The utility model relates to a technology for machining large and small holes of an engine connecting rod, in particular to a fixture for machining large and small holes of an engine connecting rod. Background Art

[0002] The engine connecting rod is the main component of the engine's torque transmission. Its basic shape is a spoon-shaped straight rod with two connecting holes at each end. One hole is rotatably connected to the bottom of the engine piston, and the other hole is rotatably connected to the crankshaft of the engine crankshaft. Thus, the linear motion of the piston is converted into the circular motion of the crankshaft. Usually, the diameter of the hole connecting the crankshaft is larger, which is called the big end hole; the diameter of the hole connecting the piston is smaller, which is called the small end hole; the two are collectively called the engine connecting rod big and small holes (see attached). Figure 1 ). In order to ensure the effective connection between the engine connecting rod and the engine crankshaft and piston and reduce shaking or noise, there are high requirements for the dimensional accuracy, surface roughness and position accuracy of the large and small holes of the engine connecting rod, especially the consistency of the hole spacing between the large and small holes.

[0003] Usually, the blank of the engine connecting rod is processed by die forging. The large and small holes of the connecting rod blank after die forging are only a prototype. In fact, the small hole may just be a pit on each of the two end faces, and it is not yet through. Therefore, it is necessary to drill the large and small holes of the engine connecting rod and chamfer the two end faces of the processed through hole. Obviously, it is very important to clamp the connecting rod blank during processing, which requires accurate positioning and stable clamping. The prior art method for processing large and small holes of engine connecting rods usually uses one or more four-bar clamping mechanisms to clamp the connecting rod blank (see attached Figure 2 ), since the four-link clamping mechanism can only clamp one point, the connecting rod blank is easy to loosen during the processing. In addition, when the four-link clamping mechanism is used to clamp the connecting rod blank, a positioning mechanism needs to be set before clamping to position the connecting rod blank to ensure the dimensional accuracy and position accuracy of the processing; thus, the structure of the entire fixture is relatively complex and the operation is also relatively complicated.

[0004] Obviously, the prior art engine connecting rod large and small hole processing methods have problems such as unstable clamping, complex fixture structure and complicated clamping operation. Summary of the invention

[0005] In order to solve the problems of unstable clamping, complex fixture structure and complicated clamping operation in the prior art engine connecting rod large and small hole processing methods, the utility model proposes an engine connecting rod large and small hole processing fixture.

[0006] The utility model provides a fixture for machining large and small holes of an engine connecting rod, comprising a bottom plate, a fixed plate, a movable plate, a guide bolt, a spring, a fixed cam, a movable cam, a fixed seat, a rocker, a connecting rod, a clamping cylinder, a push guide seat, a push plate and a push cylinder; the bottom plate is a rectangular plate; the fixed plate and the movable plate are both rectangular plates, which are relatively horizontally and vertically arranged on the left side of the middle front part of the bottom plate; on the opposite surfaces of the fixed plate and the movable plate, positioning concave steps are mirror-symmetrically arranged, and a clamping cavity is formed by the relative positioning concave steps and the gap between the fixed plate and the movable plate; the bottom curve of the positioning concave step is the same as the outer contour curve of the engine connecting rod, The middle and upper part is a trumpet-shaped opening, and the front part is provided with a discharge port; in addition, coaxial guide through holes are provided at the four corners of the fixed plate and the movable plate, and two large and small processing through holes are coaxially provided in the middle of the fixed plate and the movable plate; the diameters of the large and small processing through holes are respectively larger than the large and small holes of the engine connecting rod, and the setting positions thereof are based on the coaxiality with the large and small holes of the engine connecting rod after the engine connecting rod is placed at the set position in the clamping cavity; the fixed plate is fixed to the middle front part of the bottom plate, and the movable plate is arranged opposite to the fixed plate; there are four guide bolts and four springs, which are respectively inserted into the guide through holes at the four corners of the fixed plate and the movable plate; The diameter of the guide bolt matches the guide through hole, and the spring is installed between the opposite surfaces of the fixed plate and the movable plate, thereby forming an openable and closable structure of the fixed plate and the movable plate; the fixed cam and the movable cam are both axial cams, that is, the cam surface is arranged in the axial direction; the cam surface of the fixed cam is fixed outwardly on the back side of the movable plate, and a rotating shaft is arranged at the center of the circle; a rotating cylinder is arranged at the center of the circle of the movable cam, and the cam surface is sleeved on the rotating shaft of the fixed cam toward the fixed cam; the fixed seat is a rectangular parallelepiped and fixedly installed on the outside of the movable cam, and a through hole with a diameter matching the outer diameter of the rotating cylinder of the movable cam is arranged on the upper part; the rotating cylinder of the movable cam passes through the fixed The through hole of the fixed seat extends outward; one end of the rocker is fixedly connected to the extension section of the moving cam drum, and the other end is hinged to the connecting rod; one end of the connecting rod is hinged to the rocker, and the other end is hinged to the piston end of the clamping cylinder; the clamping cylinder is fixed to the right side of the middle rear part of the base plate; the pushing guide seat is a rectangular parallelepiped, and a through hole matching the cross-sectional shape and size of the pushing plate is provided on the upper part, and is fixed to the rear side of the fixed plate and the movable plate; the pushing plate is a long strip, and the front end passes through the through hole of the pushing guide seat and extends into the gap between the fixed plate and the movable plate, and the rear end is hinged to the piston end of the pushing cylinder; the pushing cylinder is fixed to the right side of the rear part of the base plate.

[0007] Furthermore, the two ends of the fixed plate and the movable plate are also provided with dovetail guide structures, that is, dovetail grooves are provided at the two ends of the fixed plate, and dovetail seats are provided at the two ends of the movable plate; the movable plate is slidably installed in the fixed dovetail groove through the dovetail seat.

[0008] The beneficial technical effects of the engine connecting rod large and small hole processing fixture of the utility model are that the connecting rod blank can be accurately positioned and firmly clamped; and the structure is simple and the operation is easy. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Attached Figure 1 It is a three-dimensional schematic diagram of a common specification engine connecting rod;

[0010] Attached Figure 2 It is a three-dimensional schematic diagram of a common four-bar clamping mechanism;

[0011] Attached Figure 3 It is a three-dimensional schematic diagram of the relaxation state of the engine connecting rod large and small hole processing fixture of the utility model;

[0012] Attached Figure 4 It is an exploded three-dimensional schematic diagram of the engine connecting rod large and small hole processing fixture of the utility model;

[0013] Attached Figure 5 It is a three-dimensional schematic diagram of the positioning concave steps of the opposite surfaces of the fixed plate and the movable plate of the utility model;

[0014] Attached Figure 6 It is a three-dimensional schematic diagram of the clamping state of the engine connecting rod large and small hole processing fixture of the utility model;

[0015] Attached Figure 7 It is a three-dimensional schematic diagram of another embodiment of the utility model.

[0016] The following is a further description of the engine connecting rod large and small hole processing fixture of the utility model in conjunction with the accompanying drawings and specific implementation methods. DETAILED DESCRIPTION

[0017] Attached Figure 3 This is a three-dimensional schematic diagram of the relaxation state of the engine connecting rod hole processing fixture of the utility model, attached Figure 4 This is a three-dimensional schematic diagram of the utility model of the engine connecting rod hole processing fixture, attached Figure 5 It is a three-dimensional schematic diagram of the positioning concave steps of the fixed plate and the movable plate on the opposite sides of the utility model, and Figure 6It is a three-dimensional schematic diagram of the clamping state of the engine connecting rod large and small hole processing fixture of the utility model; in the figure, 1 is a base plate, 2 is a fixed plate, 3 is a movable plate, 4 is a guide bolt, 5 is a spring, 6 is a fixed cam, 7 is a movable cam, 8 is a fixed seat, 9 is a rocker, 10 is a connecting rod, 11 is a clamping cylinder, 12 is a push guide seat, 13 is a push plate, and 14 is a push cylinder. As can be seen from the figure, the utility model engine connecting rod large and small hole processing fixture includes a base plate 1, a fixed plate 2, a movable plate 3, a guide bolt 4, a spring 5, a fixed cam 6, a movable cam 7, a fixed seat 8, a rocker 9, a connecting rod 10, a clamping cylinder 11, a push guide seat 12, a push plate 13 and a push cylinder 14; the base plate 1 is a rectangular plate; the fixed plate 2 and the movable plate 3 are both rectangular plates, which are relatively horizontally arranged vertically on the left side of the middle front part of the base plate; on the opposite surfaces of the fixed plate and the movable plate, positioning concave steps are arranged mirror-symmetrically, and the clamping cavity is formed by the relative positioning concave steps and the gap between the fixed plate and the movable plate; the bottom of the positioning concave step is curved The line is the same as the outer contour curve of the engine connecting rod, the upper and middle part is a trumpet-shaped opening, and the front part is provided with a discharge port; in addition, coaxial guide through holes are provided at the four corners of the fixed plate and the movable plate, and two large and small processing through holes are coaxially provided in the middle of the fixed plate and the movable plate; the diameters of the large and small processing through holes are respectively larger than the large and small holes of the engine connecting rod, and their setting positions are based on the coaxiality with the large and small holes of the engine connecting rod after the engine connecting rod is placed in the set position in the clamping cavity; the fixed plate is fixed to the middle front part of the bottom plate, and the movable plate is arranged opposite to the fixed plate; there are four guide bolts 4 and four springs 5, which are respectively inserted in the four corners of the fixed plate and the movable plate wherein the diameter of the guide bolt matches the guide through hole, and the spring is installed between the opposite surfaces of the fixed plate and the movable plate, thereby forming an openable and closable structure of the fixed plate and the movable plate; the fixed cam 6 and the movable cam 7 are both axial cams, that is, the cam surface is arranged in the axial direction; the cam surface of the fixed cam is fixed outwardly on the back of the movable plate, and a rotating shaft is arranged at the center of the circle; a rotating cylinder is arranged at the center of the circle of the movable cam, and the cam surface is sleeved on the rotating shaft of the fixed cam toward the fixed cam; the fixed seat 8 is a rectangular parallelepiped and fixedly installed on the outside of the movable cam, and a through hole with a diameter matching the outer diameter of the rotating cylinder of the movable cam is arranged on the upper part; the rotating cylinder of the movable cam passes through the fixed The through hole of the seat extends outward; one end of the rocker 9 is fixedly connected to the extended section of the moving cam drum, and the other end is hinged to the connecting rod; one end of the connecting rod 10 is hinged to the rocker, and the other end is hinged to the piston end of the clamping cylinder; the clamping cylinder 11 is fixed to the right side of the middle rear part of the base plate; the pushing guide seat 12 is a rectangular parallelepiped, and a through hole matching the cross-sectional shape and size of the pushing plate is provided on the upper part, and is fixed to the rear side of the fixed plate and the movable plate; the pushing plate 13 is a long strip, and the front end passes through the through hole of the pushing guide seat and extends into the gap between the fixed plate and the movable plate, and the rear end is hinged to the piston end of the pushing cylinder; the pushing cylinder 14 is fixed to the right side of the rear part of the base plate.The utility model engine connecting rod large and small hole processing fixture adopts an openable and closable structure composed of a fixed plate and a movable plate as the opening and closing body of the clamping mechanism, adopts a clamping cavity composed of positioning concave steps arranged on the opposite surfaces of the fixed plate and the movable plate as the positioning clamping body, and adopts an axial driving mechanism composed of a fixed cam and a movable cam as the clamping driving body. Under the premise of ensuring accurate positioning, the stability of the clamping is guaranteed; at the same time, the structure is simple and easy to operate. In specific operation, a manual or mechanical device is used to put the engine connecting rod blank into the clamping cavity from above the fixed plate and the movable plate. Since the bottom curve of the clamping cavity is the same as the contour of the connecting rod blank, and the two sides of the clamping cavity are trumpet-shaped openings, the connecting rod blank can smoothly enter the clamping cavity and be placed in the set position to achieve accurate positioning. The clamping cylinder is turned on, and the clamping cylinder piston pulls the rocker to rotate counterclockwise. Under the interaction of the movable cam and the fixed cam, the movable plate is pushed toward the fixed plate until the connecting rod blank is clamped in the clamping cavity. Since the engine connecting rod blank is clamped between the end faces of the two positioning concave steps, it is not only the surface contact and pressure, but the contour of the concave step also limits the movement of the connecting rod blank, so as to achieve a stable clamping of the connecting rod blank. After the processing of the large and small holes of the connecting rod blank is completed, the clamping cylinder is turned on again, and the clamping cylinder piston pushes the rocker to rotate clockwise. Under the action of the spring, the moving plate moves away from the fixed plate, and the connecting rod blank is in a non-clamped state. Turn on the push cylinder, and the push cylinder piston pushes the push plate to move toward the discharge port, pushing the processed connecting rod out of the clamping cavity. The push cylinder piston pulls the push plate back to its original position to start the next processing cycle.

[0018] Attached Figure 7 This is a three-dimensional schematic diagram of another embodiment of the utility model, in which 1 is a bottom plate, 2 is a fixed plate, 3 is a movable plate, 6 is a fixed cam, 7 is a movable cam, 8 is a fixed seat, 9 is a rocker, 10 is a connecting rod, 11 is a clamping cylinder, 12 is a push guide seat, 13 is a push plate, 14 is a push cylinder, and 15 is a dovetail guide structure. As can be seen from the figure, in order to further improve the reliability and accuracy of the movement of the movable plate to the fixed plate, as one of the preferred schemes, the two ends of the fixed plate and the movable plate are also provided with a dovetail guide structure, that is, a dovetail groove is provided at the two ends of the fixed plate, and a dovetail seat is provided at the two ends of the movable plate; the movable plate is slidably installed in the fixed dovetail groove through the dovetail seat. Since the dovetail guide structure is added between the movable plate and the fixed plate, the movable plate moves more smoothly, reliably, and accurately when it moves relative to the fixed plate. As a result, the reliability and stability of positioning and clamping are further improved.

[0019] Obviously, the beneficial technical effect of the engine connecting rod large and small hole processing fixture of the utility model is that it can accurately position the connecting rod blank and clamp it firmly; and it has a simple structure and is easy to operate.

Claims

1. A fixture for machining large and small holes of engine connecting rods, characterized in that: The processing fixture comprises: A bottom plate, a fixed plate, a movable plate, a guide bolt, a spring, a fixed cam, a movable cam, a fixed seat, a rocker, a connecting rod, a clamping cylinder, a push guide seat, a push plate and a push cylinder; the bottom plate is a rectangular plate; the fixed plate and the movable plate are both rectangular plates, which are arranged vertically on the left side of the middle front part of the bottom plate relative to the horizontal direction; on the opposite surfaces of the fixed plate and the movable plate, positioning concave steps are arranged mirror-symmetrically, and a clamping cavity is formed by the relative positioning concave steps and the gap between the fixed plate and the movable plate; the bottom curve of the positioning concave step is the same as the outer contour curve of the engine connecting rod, the upper and middle part is a trumpet-shaped opening, and the front is provided with an outlet Inlet; in addition, coaxial guide through holes are arranged at the four corners of the fixed plate and the movable plate, and two large and small processing through holes are coaxially arranged in the middle of the fixed plate and the movable plate; the diameters of the large and small processing through holes are respectively larger than the large and small holes of the engine connecting rod, and the setting positions thereof are based on the coaxiality with the large and small holes of the engine connecting rod after the engine connecting rod is placed in the set position in the clamping cavity; the fixed plate is fixed to the middle front part of the bottom plate, and the movable plate is arranged opposite to the fixed plate; the guide bolts and springs are four in number, which are respectively inserted into the guide through holes at the four corners of the fixed plate and the movable plate; wherein the diameter of the guide bolts The diameter of the spring matches the guide through hole, and the spring is installed between the opposite surfaces of the fixed plate and the movable plate, thereby forming an openable and closable structure of the fixed plate and the movable plate; the fixed cam and the movable cam are both axial cams, that is, the cam surface is arranged in the axial direction; the cam surface of the fixed cam is fixed outwardly on the back side of the movable plate, and a rotating shaft is arranged at the center of the circle; a rotating cylinder is arranged at the center of the circle of the movable cam, and the cam surface is sleeved on the rotating shaft of the fixed cam toward the fixed cam; the fixed seat is a rectangular parallelepiped and fixedly installed on the outside of the movable cam, and a through hole with a diameter matching the outer diameter of the rotating cylinder of the movable cam is arranged on the upper part; the rotating cylinder of the movable cam passes through the through hole of the fixed seat to Outward extension; one end of the rocker is fixedly connected to the extension section of the moving cam rotating cylinder, and the other end is hinged to the connecting rod; one end of the connecting rod is hinged to the rocker, and the other end is hinged to the piston end of the clamping cylinder; the clamping cylinder is fixed to the right side of the middle rear part of the base plate; the pushing guide seat is a rectangular parallelepiped, and a through hole matching the cross-sectional shape and size of the pushing plate is provided on the upper part, and is fixed to the rear side of the fixed plate and the movable plate; the pushing plate is a long strip, and the front end passes through the through hole of the pushing guide seat and extends into the gap between the fixed plate and the movable plate, and the rear end is hinged to the piston end of the pushing cylinder; the pushing cylinder is fixed to the right side of the rear part of the base plate.

2. The engine connecting rod large and small hole processing fixture according to claim 1 is characterized in that: The two ends of the fixed plate and the movable plate are also provided with dovetail guide structures, that is, dovetail grooves are provided at the two ends of the fixed plate, and dovetail seats are provided at the two ends of the movable plate; the movable plate is slidably installed in the fixed dovetail groove through the dovetail seat.

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