Automatic indexing, positioning and clamping mechanism of crankshaft connecting rod neck lathe

Abstract

The utility model discloses an automatic indexing, automatic positioning and clamping mechanism of a crankshaft connecting rod neck lathe. The transposition gear speed changing box rotates clockwise along the swing center shaft under the action of the transposition oil cylinder till the transposition gear is meshed with the chuck gear, the transposition gear is driven by the servo motor through the speed reducer to transmit rotation to the chuck gear, and indexing transposition of the crankshaft is completed. Before the main shaft is started, the transposition gear is separated from the chuck gear under the action of the transposition oil cylinder. Compared with the prior art, the automatic indexing, automatic positioning and clamping mechanism of the crankshaft connecting rod neck lathe has the advantages of being simple in structure, convenient to operate, good in flexibility, high in efficiency and low in cost, obviously improving the machining technology of crankshaft connecting rod necks, further improving the machining quality and being favored and praised by crankshaft machining factories.

Description

Technical Field

[0001] The utility model relates to the technical field of crankshaft processing, in particular to an automatic indexing, automatic positioning and clamping mechanism for a crankshaft connecting rod neck lathe. Background Art

[0002] The crankshaft is one of the most difficult core parts of the internal combustion engine to process. As a mass-produced automobile crankshaft, it has undergone considerable evolution in design, materials and processing due to the constraints of cost and benefit. As people's requirements for environmental protection, improved performance and reduced manufacturing costs increase, this evolution will continue. The crankshaft journal or connecting rod journal has a geometric shape of a short cylinder, and turning is undoubtedly the most traditional, economical, simple and reliable process. The turning process of the crankshaft main journal and connecting rod journal has long dominated the history of crankshaft processing and manufacturing. The turning process of the main journal is still widely used. However, if it is used for connecting rod journal processing, the dynamic balance problem caused by the deviation of the mass center of the crankshaft from the rotation center in the clamping state and the position accuracy of the connecting rod journal become insurmountable difficulties, which seriously restricts the production efficiency and the realization of automated production methods. At present, there are many process solutions in use in the crankshaft manufacturing industry, such as turning and pulling, internal milling, external milling, etc. Only a few machine tools are used in a limited range for crankshaft turning and pulling. This is a broaching process that can be done either conventionally by straight turning and broaching with a tangential feed to the rotating crankshaft, or by rotary broaching with a subsequently developed circular or spiral broach. Although this method is very efficient, it has not been widely used due to its lack of flexibility. Internal milling of crankshafts, also known as spiral or planetary milling, allows heavy milling with a long cutting time. The crankshaft passes through the rotating milling cutter. The indexable inserts are arranged on the inner surface of the milling cutter and can be used to machine the main journal, connecting rod journal and fan-shaped block sides of the crankshaft. It is a very stable machining method, mainly used for large crankshafts or when the blank allowance is large. External milling of crankshafts is mainly used for large-scale machining of medium and small automotive crankshafts. It can be regarded as a high-speed rotating three-sided edge milling cutter that processes the workpiece surface while the crankshaft is slowly rotating as a feed motion. The method is characterized by a large amount of metal removal. Although the internal and external milling processes for crankshaft machining have the advantages of high efficiency and stability, the cost of the machine tool itself and the cost of use are high, and its scope of use has certain limitations. Utility Model Content

[0003] The utility model aims to provide an automatic indexing, automatic positioning and clamping mechanism for a crankshaft connecting rod neck lathe to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above purpose, the utility model provides the following technical solutions: an automatic indexing, automatic positioning and clamping mechanism for a crankshaft connecting rod neck lathe, wherein the indexing gear transmission box rotates clockwise along the swing center axis under the action of the indexing oil cylinder, so that the indexing gear meshes with the chuck gear, and the indexing gear is driven by a servo motor through a reducer to transmit the rotation to the chuck gear, thereby completing the indexing and indexing of the crankshaft. Before the spindle is started, the indexing gear is disengaged from the chuck gear under the action of the indexing oil cylinder.

[0005] Compared with the prior art, the beneficial effects of the utility model are: the crankshaft connecting rod neck lathe has automatic indexing, automatic positioning, and clamping mechanisms, which have simple structure, convenient operation, good flexibility, high efficiency, and low cost. It has significantly improved the processing technology of the crankshaft connecting rod neck, and the processing quality has also been further improved, and has been favored and praised by crankshaft processing manufacturers. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is an axonometric drawing of the main structure of the utility model;

[0007] Figure 2 This is a cross-sectional view of the main structure of the utility model;

[0008] Figure 3 It is a schematic diagram of the main structure of the utility model;

[0009] Figure 4 It is a structural schematic diagram of the utility model;

[0010] Figure 5 It is a structural sectional view of the utility model.

[0011] In the figure: 1- indexing gear box, 2- indexing cylinder, 3- swing center shaft, 4- indexing gear, 5- chuck gear, 6- servo motor, 7- reducer, 8- indexing plate, 9- three-jaw self-centering chuck, 10- positioning pin, 11- eccentric chuck seat, 12- connecting plate, 13- cylinder body, 14- three-jaw chuck body, 15- piston, 16- push plate, 17- push rod, 18- base claw, 19- claw, 20- guide disc, 21- axial locking ring. DETAILED DESCRIPTION

[0012] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0013] See also Figure 1-5The utility model provides a mechanism consisting of three parts: a shifting gear clutch conversion mechanism, a dividing plate positioning mechanism, and a self-centering chuck clamping mechanism. The center line of the crankshaft connecting rod neck of the shifting gear clutch conversion mechanism must be ensured to coincide with the rotation center of the lathe spindle during the turning process and meet the requirements for its distribution angle. The function of indexing and shifting the crankshaft in the circumferential direction is indispensable. During the indexing and shifting, the lathe spindle is in a directional parking state. The shifting gear transmission box rotates clockwise along the swing center axis under the action of the shifting oil cylinder, so that the shifting gear is engaged with the chuck gear. The shifting gear is driven by the servo motor through the reducer to transmit the rotation to the chuck gear, completing the indexing and shifting of the crankshaft. Before the spindle is started, the shifting gear is disengaged from the chuck gear under the action of the shifting oil cylinder, stays in a safe position and sends a signal to start the spindle and start cutting. The shifting angle depends on the number of crankshaft connecting rod necks and is pre-set in the control system.

[0014] The indexing plate positioning mechanism is coaxially fixedly connected with the three-jaw self-centering chuck. When indexing, first withdraw the locating pin upward from the locking groove, and then rotate it a certain angle under the drive of the servo motor. When the indexing is completed, the locating pin is inserted into the locating groove of the indexing plate under the action of oil pressure, so that the three-jaw self-centering chuck and the eccentric chuck seat form a tightly connected whole. The eccentric chuck seat is fixed to the lathe spindle flange through the connecting plate, and the crankshaft main journal is clamped on the three-jaw self-centering chuck to realize the turning of the crankshaft connecting rod neck. The manufacturing accuracy of the indexing plate and the locating pin is very important, which will directly affect the position accuracy of the connecting rod neck.

[0015] 3. Self-centering chuck clamping mechanism: see (Attached Figure 4 ) Figure 5 The clamping action of the three-jaw self-centering chuck is driven by hydraulic pressure. The cylinder body is coaxially fixedly connected with the three-jaw chuck body. The outer circle of the cylinder body is clearance-matched with the inner hole of the eccentric chuck seat. The piston inside the cylinder body drives the push plate forward under hydraulic drive. There are three equally divided push rods on the push plate. The push rods and the base jaws are matched through inclined planes. The claws are installed on the base jaws. The forward movement of the push rods will push the claws to move toward the center to clamp the spindle neck. The three-jaw self-centering chuck is installed in the eccentric chuck seat. There is a certain distance between its center and the center of the eccentric chuck seat. This distance is designed according to the stroke size of the crankshaft. In order to adapt to the different strokes of various crankshafts, the eccentric chuck seat is connected with the guide disc. The eccentric chuck seat can move linearly along the guide groove of the guide disc. The guide disc is coaxial with the spindle. The distance from the center of the three-jaw self-centering chuck to the machine tool spindle is adjusted to make the crankshaft connecting rod neck coaxial with the spindle, so that crankshafts with different strokes within a certain range can be processed. There is an axial locking ring in the cylinder body, which is hydraulically driven to fit tightly with the eccentric chuck seat. The three-jaw self-centering chuck and the eccentric chuck seat are locked together by friction to prevent the axial movement of the three-jaw self-centering chuck. When indexing, the hydraulic oil in this line is first depressurized and then indexing is performed.

[0016] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic indexing, automatic positioning and clamping mechanism for a crankshaft connecting rod neck lathe, characterized in that: It includes indexing gear clutch conversion mechanism, indexing plate positioning mechanism, and self-centering chuck clamping mechanism; The indexing plate positioning mechanism comprises an indexing plate (8) and a three-jaw self-centering chuck (9) which are coaxially fixedly connected. When indexing, the positioning pin (10) is firstly withdrawn upward from the locking groove, and then rotated to a certain angle under the drive of the servo motor (6). When the indexing is completed, the positioning pin (10) is inserted into the positioning groove of the indexing plate (8) under the action of oil pressure, so that the three-jaw self-centering chuck (9) and the eccentric chuck seat (11) form a tightly connected whole. The eccentric chuck seat (11) is fixed to the main shaft flange of the lathe through a connecting plate (12), and the main shaft neck of the crankshaft is clamped on the three-jaw self-centering chuck (9).

2. The automatic indexing, automatic positioning and clamping mechanism for a crankshaft connecting rod neck lathe according to claim 1, characterized in that: The indexing gear clutch conversion mechanism comprises: the indexing gear transmission box (1) rotates clockwise along the swing center axis (3) under the action of the indexing oil cylinder (2) so that the indexing gear (4) is meshed with the chuck gear (5); the indexing gear (4) is driven by the servo motor (6) through the reducer (7) to transmit the rotation to the chuck gear (5) to complete the indexing indexing of the crankshaft; before the main shaft is started, the indexing gear (4) is disengaged from the chuck gear (5) under the action of the indexing oil cylinder (2).

3. The automatic indexing, automatic positioning and clamping mechanism of a crankshaft connecting rod neck lathe according to claim 1, characterized in that: The self-centering chuck clamping mechanism comprises a three-jaw self-centering chuck (9) whose clamping action is driven by hydraulic pressure, a cylinder body (13) and a three-jaw chuck body (14) are coaxially fixedly connected, the outer circle of the cylinder body (13) and the inner hole of the eccentric chuck seat (11) are clearance-matched, and a piston (15) inside the cylinder body (13) drives a push plate (16) to move forward under hydraulic drive, and there are three equally divided push rods (17) on the push plate (16), the push rods (17) and the base jaws (18) are matched through inclined surfaces, and the clamping jaws (19) are installed on the base jaws (18), and the forward movement of the push rods (17) will push the clamping jaws (19) to move toward the center to clamp the main shaft neck.

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