Crankshaft connecting rod neck turning automatic clamp with indexing function

Abstract

The utility model discloses an automatic fixture with an indexing function for turning a crankshaft connecting rod neck, which is used in a turning machine tool for machining the crankshaft connecting rod neck, so that the automation level, the flexibility, the safety and the reliability of the machine tool are improved. According to the invention, a mechanism driven by a servo motor and driven by a speed reducer is adopted to realize indexing, and a method of combining a positioning pin with an indexing plate is adopted to realize angular positioning, so that the problem is solved. After the indexing transmission action is completed and before the main shaft is started, the transposition gear and the clamping gear which are in a meshed state need to be separated and swing to a safe area along with the transposition gear transmission box. The position-adjustable function of the three-jaw centering chuck plays an important role in improving the flexibility of the turning clamp for the crankshaft connecting rod neck, when the distance between the machined crankshaft connecting rod neck and the shaft neck is changed, new requirements can be met only by adjusting the position of the chuck, and a lot of production preparation time and manufacturing cost can be saved. And the operation and measurement of adjusting the position of the chuck are very simple and convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of metal cutting equipment, and particularly relates to an automatic fixture for turning a crankshaft connecting rod neck with a indexing function. Background Art

[0002] Although the turning process of the crankshaft connecting rod neck occupies a place in the crankshaft manufacturing industry, the current technology is not yet perfect, and there are some unfavorable factors such as multiple clamping, poor flexibility, inconvenient adjustment, and difficulty in product changeover. In order to improve product quality and production efficiency, make up for the deficiencies of existing fixtures, and further develop the turning process of the crankshaft connecting rod neck, the appearance of a turning fixture for the connecting rod neck with an automatic indexing and positioning function, good flexibility, safety and reliability, and convenient adjustment is expected by relevant practitioners. At present, the fixtures used by many crankshaft manufacturing enterprises adopting the turning process of the connecting rod neck do not have the function of automatic indexing and rotation. Taking a six-cylinder crankshaft as an example, the six connecting rod necks need to be clamped and positioned three times on three machine tools respectively to complete. This process method has a long auxiliary time, low indexing and positioning accuracy, and high labor intensity. Content of the Utility Model

[0003] The purpose of the utility model is to provide an automatic fixture for turning a crankshaft connecting rod neck with a indexing function, so as to solve the problems put forward in the above background art.

[0004] To achieve the above object, the present utility model provides the following technical solutions: The object of the present invention is to provide an automatic fixture for turning the connecting rod journal of a crankshaft, which has functions of automatic indexing and rotation, centering and clamping, and adjustable center distance, and is used in a machine tool for turning the connecting rod journal of a crankshaft, so as to improve the automation level, flexibility, safety and reliability of the machine tool. The present invention adopts a mechanism driven by a servo motor and transmitted by a speed reducer to realize indexing and rotation. A plurality of positioning grooves are machined on a dividing plate coaxially and fixedly connected with a three-jaw self-centering chuck. With the cooperation of positioning pins, precise positioning after the chuck rotates can be realized. The angular positioning is realized by the method of combining positioning pins with the dividing plate, thus solving the problem. After the indexing and transmission action is completed and before the main shaft starts, the indexing gear in the meshing state and the chuck gear and the indexing gear swing to a safe area together with the indexing gear gearbox to prevent collision with the rotating fixture. The reciprocating swing clutch action of the indexing gear gearbox is driven by an indexing oil cylinder installed on the main shaft box. In the present invention, a three-jaw self-centering chuck is used to replace the structure of positioning and pressing the jaws with a V-shaped block in the past. This change makes it possible to realize automatic indexing and rotation. Otherwise, during the rotation process, the position of the center of the crankshaft journal will change, and the distance between the connecting rod journal and the journal cannot be guaranteed. Compared with the prior art, the beneficial effect of the present utility model is that the adjustable position function of the three-jaw self-centering chuck plays an important role in improving the flexibility of the fixture for turning the connecting rod journal of a crankshaft. When the distance between the machined connecting rod journal of a crankshaft and the journal changes, as long as the position of the chuck is adjusted, the new requirements can be met, and a lot of production preparation time and manufacturing cost can be saved. The operation and measurement of adjusting the position of the chuck are very intuitive and simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 Schematic diagram of the indexing gear clutch conversion mechanism of the present utility model;

[0006] Figure 2 Schematic diagram of the indexing gear gearbox of the present utility model;

[0007] Figure 3 Schematic diagram of the indexing and positioning mechanism of the present utility model;

[0008] Figure 4 is Figure 3 Cross-sectional view taken along line C-C in

[0009] Figure 5 Schematic diagram of the structure of the automatic fixture for turning the connecting rod journal of a crankshaft of the present utility model;

[0010] Figure 6 Cross-sectional view of the fixture of the present utility model.

[0011] In the figure: 1 - transmission, 2 - indexing cylinder, 3 - swing 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 block, 14 - three-jaw chuck body, 15 - piston, 16 - push plate, 17 - push rod, 18 - base jaw, 19 - chuck jaw, 20 - guide disc, 21 - axial locking ring. Detailed implementation manners

[0012] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0013] Please refer to Figures 1-5 , the key technology for the turning of the crankshaft connecting rod journal to be completed in one clamping in the present invention lies in the realization of the reliability and accuracy of the indexing and positioning of the three-jaw chuck. The method adopted in this design is: the indexing action is driven by a servo motor and transmitted to the three-jaw chuck through a reducer and an indexing gear transmission. During the transmission process, due to the existence of gear clearance, the accuracy cannot meet the requirements. In this design, the method of immediately positioning by a pin after indexing is adopted to ensure the positioning accuracy of the three-jaw chuck.

[0014] The indexing and positioning functions of the three-jaw self-centering chuck are completed in the state of the machine tool spindle being oriented and stopped. Before the spindle starts, the indexing gear must disengage from the chuck gear and move to a safe area, and then restore the meshing state between the two gears when turning to the next connecting rod journal for turning. This repeated engaging and disengaging action of the gear transmission is realized by the swing of the indexing gear transmission driven by the indexing cylinder. The position adjustable function of the three-jaw self-centering chuck plays an important role in improving the flexibility of the turning fixture for the crankshaft connecting rod journal. When the distance between the machined crankshaft connecting rod journal and the journal changes, just adjust the position of the chuck to meet the new requirements, which can save a lot of production preparation time and manufacturing costs. The operation and measurement of adjusting the chuck position are very intuitive and simple. The specific structure is as follows: both sides of the eccentric chuck seat connecting the three-jaw chuck are fitted with the guide grooves of the guide disc and can move in the grooves, so as to change the distance from the center of rotation of the fixture. After the center distance between the three-jaw chuck and the spindle is adjusted to the value specified in the crankshaft drawing, use the T-shaped block and screw provided on the guide disc to lock the eccentric chuck seat and the guide disc.

[0015] Although embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. An automatic fixture for turning crankshaft connecting rod neck with indexing function, characterized in that: It includes a three-jaw self-centering chuck, the intermittent rotation of which is driven by a servo motor and realized through a reducer and a gearbox. A dividing plate coaxially fixedly connected to the three-jaw self-centering chuck is processed with a plurality of positioning grooves, and the precise positioning of the chuck after rotation can be realized with the cooperation of the positioning pin. The three-jaw self-centering chuck can move in the guide groove of the guide disc along with the eccentric chuck seat matched therewith to change the distance from the rotation center of the clamp. After the chuck position is adjusted, the eccentric chuck seat and the guide disc are locked by screws and T-blocks.

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