When the mechanism of opening and closing of the mechanism is in the open state, the handle is used to operate the opening cam to rotate clockwise. When it rotates by about 180°, the unlocking star wheel is turned by the opening cam, and the fixed axis is rotated around it. Rotate counterclockwise about 20° to unlock the star wheel and then turn the closing switch to rotate clockwise around the fixed axis. At this time, the constraint that the closing trip wheel rotates clockwise is released (unlocked), and the mechanism is performed. Closing action.
During the closing operation, both the closing spring and the opening spring compress the energy storage at the same time. First, since the structure of the opening cam is a crankshaft, when the closing operation is performed, the closing spring is compressed and stored, and is unlocked when the operation is closed to the closing pulley. At this time, the closing spring starts to release the spring energy and pushes The closing cam disc rotates clockwise, the unlocked closing tripping wheel is disengaged, the energy of the closing spring is released, and the closing operation is completed; secondly, during the turning cam rotation, the opening cam and the cam are synchronized When the hour hand rotates, the cam pushes the push rod turntable to rotate around the axis of the closing cam plate, and the push rod turntable pushes the sliding bracket to rotate around the axis of the closing cam plate, thereby compressing the opening spring for energy storage.
When the mechanism is in the closing state, if the mechanism needs to be opened, the opening button of the mechanism is pressed, and the tripping wheel is rotated by the force of the opening button to rotate in a clockwise direction, and the opening spring releases energy. The sliding bracket pushes the closing cam disc to rotate counterclockwise until the opening is completed, and the components such as the closing tripping wheel, the closing scorpion, the unlocking star wheel are reset by the return spring, and the state when the opening is maintained is shown.
During each operation, whether it is the closing or opening operation of the main knife or the operation of the grounding knife, the welding assembly of the closing cam disc rotates according to a fixed trajectory, and when it rotates, the connecting rod is driven. The rod drives the output arm to rotate around the fixed shaft, and the output arm further drives the transmission member connected to the load switch to realize the function of the mechanism.
112 mechanism closing slip
2 judgment method of closing and slipping
Analysis of 3 closing and slipping problems
The problem of slippage during the closing operation of the mechanism mainly occurs in the fastening parts where the two parts of the opening cam and the tripping wheel are in contact. It can be seen from the above-mentioned mechanism closing operation slip phenomenon that if the tripping cam and the tripping tripping wheel are fastened, the mechanism will not be closed and slipped if the opening and closing tripping wheel is controlled to rotate clockwise.
311 plane type buckle surface slip analysis
The fastening surface of the closing cam of the mechanism adopts a flat design, and the fastening surface of the opening cam is tangent to the roller of the opening and disengaging wheel, that is, the plane is in contact with the cylindrical surface.
The action point (fastening point) of the fastening force, the fastening force and the normal line are collinear, and the buckle faces of the three angles change the direction of the fastening force and the normal. According to the graphical analysis, only the triangle ABC is in equilibrium, and the mechanism is closed. It will not slip during operation.
The extension line of the fastening force F 1 and the line segment BC are not sufficient for the mechanism to simply satisfy the closing operation of the mechanism, and the actual needs of the mechanism closing and opening work must be considered.
312 plane type buckle surface combination, slip analysis when opening, when the force arm L 1 = 0, the dead point position occurs. When the mechanism performs the opening operation, press the opening button, the dead point position is destroyed, the mechanism can Smoothly opened. Because the dead point is easily destroyed by external forces, the opening operation has a feeling of being triggered. If the dead point is destroyed by external vibration, the mechanism will open the door by itself.
The force of the buckle force to the point C of the point C is zero in the design theory. In the actual production process, due to the cumulative error in the processing and production process, the force arm L≠0 occurs, and when the torque is large, the brake can be removed. The buckle wheel rotates around point C, and it will slip when the mechanism is closed. For Figure 3 (c), the torque makes the opening cam and the tripping buckle buckle stronger, the triangle ABC is more stable, and the mechanism is not closed. Slip, however, when the opening operation is performed, the reverse torque is overcome to increase the tripping force of the opening button.
313 Mechanism Closing and Sliding Common Treatment Method The method of slipping emergency treatment during the closing operation of the mechanism is usually to repair the small pit at the fastening plane of the opening cam, and use the multi-point force to control the mechanism to slip. Although this solves the problem of closing and slipping, it is difficult to grind, it is more difficult to repair it, and it also destroys the surface of high-frequency parts. The tripping force of the opening button is often increased due to excessive grinding.
Therefore, in mass production, the design of the flat fastening surface is easy to bury the hidden danger of excessive slipping or tripping force.
4The arc-shaped fastening surface is used to solve the slipping problem. The fastening surface of the opening cam adopts the curved surface design, and the circular arc has a radius of 33 mm, as shown in Fig. 4. The action points of the forces F and F' are also the tangent points inscribed by the two arcs, so the point of action of the force F(F') is collinear with the B (B') point and the C point 3 points, and (a) The process is the same, so it is preliminarily believed that the arc-shaped fastening surface will not slip.
The safety fastening range of the flat type buckle surface is a dead point position, and the opening button is pressed to immediately open the door; and the safety fastening range of the curved surface type fastening surface is an arc length of 2 1 3 mm, in the range of the arc length The inside is the dead point position. Even if the opening button is pressed, the tripping wheel of the opening should move the arc length of 2 1 3 mm to trip and the tripping force of the button is even. Therefore, the arc-shaped fastening surface has higher reliability and safety than the planar fastening surface. The processing process of the arc-shaped fastening surface should also be strict. It cannot be processed into a plane because the arc of the machining is short. Only the arc surface can fundamentally solve the phenomenon that the mechanism is closed and slipped, and the tripping force of the opening is uniform.
5 Conclusion The curved surface fastening surface not only solves the problem of the mechanism closing and slipping, but also makes the manual tripping force even and smooth. When the mechanism needs to increase the electric module, the electric tripping force is also easier to match. The flat type fastening surface can solve the problem that the closing does not occur, but it will increase the tripping force of the opening, which is not conducive to increasing the opening operation after the electric module. It has been verified by practice that the arc-shaped fastening surface design not only solves the problem of the mechanism closing and slipping, but also has certain benefits for the operation after adding the electric module, which is helpful for the reliable operation of the mechanism products.
Solar Lights,String Lights,Garden Lights,Solar Garden Lights
Foshan Nanhai Pinming Electrical Appliance Co.,Ltd , https://www.mavcadonf.com