SU795753A1 - Apparatus for working cams - Google Patents

Description

(54) DEVICE FOR PROCESSING CAMS

I

The invention relates to a machine tool industry and can be used for machining cams, mainly diametrical, the profile of which has sections of stands.

Apparatuses for treating cusps with a rotary table for a part and a master wheel, kinematically connected by means of a Maltese mechanism and two gearboxes, one of which is placed between the master wheel and the Maltese cross, and the other one associated with the Maltese wheel mechanism 1.

However, the dynamic characteristics of the cam profiles obtained on these devices in the range of movement of the pusher depend only on the number of grooves of the cross of the Maltese mechanism. The latter reduces the applicability of these cams.

The purpose of the invention is to expand the dynamic characteristics of multi-jaw cams.

The goal is achieved by introducing an additional gearbox and a gearbox placed between the second gearbox and the table for the part into the kinematic chain between the master curve switch and the table. cogwheel gears having areas with non-circular crown gears, the gear ratios of the second and additional gearboxes being respectively

i t 12 2p,

and the central angles of the non-circular portions of the gears are

23G-TTKT

2- + in

whereK, g-

the ratio of the angles of the interval height to the angles of the interval of motion of the Maltese mechanism;

Z is the number of grooves of the cross; ø number tsevok Krivoschip Maltese mechanism; n is the number of teeth manufactured

fist.

The drawing shows a diagram of the proposed device.

The device includes a frame 1, in the guides of which a slider 2 is installed. In the guides of the slide that are parallel to the bed guides, a carriage 3 is mounted. On the carriage there is a setting crank 4 and a rotary table 5, as well as the gearboxes connecting them 6, 7 and 8 , the Maltese mechanism with Krivoschip 9 and Cross 10 and a pair of interacting combined gear rails 11 and 12. On the carriage there is a flywheel 13 and a worm pair 14, which connects this flywheel to the wheel 11. The driver Krivoschip 4 is connected with the stone 15 by means of 16 fats 2. Sled straps bonded to the frame 17, a pair of screw with the flywheel 18. On the turntable set the workpiece 19. With the workpiece 19 engages the working body 20. Combined gear wheels 11 and 12 are formed as follows. They are made in the form of two rigidly interconnected sectors. Some of the sectors are part of round ones, and the other sectors are in the form of non-circular symmetrical, for example, transformed elliptical or logarithmic gears. The non-circular sectors of the combined wheels 11 and 12 realize the variable gear ratio between the gears 7 and 8. A straight line connecting the centers of rotation of the rotary table 5 and the working body 20 is parallel to the direction of movement of the slide 2 and carriage 3. The manufacture of cams, whose profile has sections of stands The proposed device is manufactured as follows. The part is mounted on the table 5. When the flywheel 13 rotates, the movement through the worm gear pair 14 is transmitted to the combined gear wheel 11. The continuous rotation of this wheel through the other combined wheel 12, the Maltese mechanism and gearboxes 6 and 7 is converted into a discrete rotational movement of the setting crank 4, which by means of stones 15 and fixed guides 16 is transformed into discrete reciprocating movement of carriage 3. When non-circular sectors of the combined wheels of the coil (s) of the crank 9 p are interacting ohodit along the slot 10 and the cross drive crank 4 is rotated by an angle of 180 °, and the carriage 2 with a table 5 perehodnt from one extreme position to another. This condition determines the gear ratio of the gearbox 6 between the cross and the setting crank i 2 / Z. It also defines the condition of combining wheels, as the condition of equal ratio of the central angle of the round and non-circular parts of these wheels to the ratio of the height intervals and movement of the Maltese mechanism. „- 1 + kV and also the gear ratio of the gearbox 7 between the combined gears and the crank mechanism of the Maltese mechanism i m. When passing the bobbin (s) outside the grooves of the cross, the carriage with the table in the slide does not move. At the same time, the continuous rotation of the wheel 1 through the gear 8 is converted into a continuous rotation of the table 5. Thus, the table receives a portable discrete reciprocating movement with the carriage and relative rotational continuous movement relative to the carriage. At the same time, the working body 20 processes the cam profile on the workpiece 19 mounted on the rotary table 5. The full profile of one tooth is processed by double passing the bobbin (s) of the crank 9 along the grooves of the cross 10, at which the carriage performs a full swing, and the combined wheels, in accordance with the condition of their compilation make two full turns. The latter determines the gear ratio of the gearbox 8 between the wheels and the turntable 1g 2-c ,. With the passage of the bobbin (s) outside the grooves of the cross and the interaction of the round sections of the wheels on the workpiece, the radius sections of the extrusion are processed, and during the passage of the bobbins (the conversions) along the grooves of the cross and the interaction of the non-circular sectors of these wheels, the transitional sections (parts of the pusher intervals). If the cam has an odd number of teeth, then it has the property of diametry due to the symmetry of the process. The magnitude of the oscillation of the carriage and the stroke of the cam being machined is determined by changing the length of the driver cry. The initial position of the workpiece relative to the working body and, accordingly, the minimum radius of sections of height, equal to the radius of the cam starting washer, is set by moving the slide 2 with the carriage 3 by means of a screw pair 17 from the flywheel 18. With a constant number of grooves of the cross of the Maltese mechanism, the dynamic characteristics of the cam profile in the interval of movement are the maximum (minimum) gear ratio of non-circular sectors of the combined gear wheels, which depends on the ratio of max. maximum and minimum radius vectors of the dividing curves of these sections. If the relative position of the wheels is as shown in the drawing, then the dynamic characteristics of the profile will be less than when receiving the cam without using these wheels. If the wheels are set, then the dynamic characteristics increase.

Claims (1)

1. Copyright certificate. The USSR on application number 2666658 / 25-08, cl. B 23 C 3/08, 1978.