JPS6137899Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a link mechanism that allows smooth operation.

FIG. 1 shows an embodiment of the link mechanism. In the figure, reference numeral 1 denotes a driving body, which is supported by a fixed rotational support A and is applied with a rotational torque _T1 in a clockwise direction. 2
is a first link, one end of which is supported by the driving body 1 at a movable rotation fulcrum E, and the other end supported by one end of the second link 3 at a movable rotation fulcrum F. The other end of the second link 3 is supported by a fixed rotation fulcrum B. On the other hand, one end of the third link 4 is supported by the movable rotation fulcrum F, and the other end of the third link 4 is supported by the latch 5 at the movable rotation fulcrum G.
The latch 5 is supported on a fixed rotation fulcrum C. 6
is a trigger, on which a trigger roller 7 is supported at a movable rotational fulcrum H, and the trigger 6 is supported at a fixed rotational fulcrum D and rotates in a counterclockwise direction.
T ₂ is energized. The trigger roller 7 of the trigger 6 engages with the notch 5a of the latch 5 to restrict rotation of the latch 5.

Next, the effect will be explained. Now, rotation torque
When the trigger 6 is rotated clockwise by applying a torque that overcomes T ₂ , the trigger roller 7 comes off from the notch 5 a of the latch 5 , and the driver 1 is rotated clockwise by the force of the rotational torque T ₁ . and stops at the chain line position. With this rotation of the drive body 1, the link mechanism operates along a predetermined trajectory, and each moving rotation fulcrum E to H is
Move from E′ to H′ and stop.

Next, when a rotational torque larger than rotational torque T ₁ is applied to the rotated driving body 1 in the counterclockwise direction and the rotational torque is reversed to the solid line position, the link mechanism traces a trajectory opposite to that described above, and the moving rotation fulcrum E′～H′ is E～
Move to H. At this time, the trigger roller 7 is in contact with the circumferential surface of the latch 5 under the force of rotational torque _T2 , so when the latch rotates and returns to the solid line position, it automatically engages with the notch 5a, and the entire link mechanism to restrain.

A vector diagram of this link mechanism when it is locked is shown in FIG. In order to make the initial movement of the link mechanism smooth, it is necessary to increase the axial component force _P2 of the third link 4. That is, the component force P ₂ is the first link 2
It is understood that it depends on the intersection angle θ of the axes of the second link 3 and the second link 3. This intersection angle θ varies greatly depending on the lengths of the first link 2 and the second link 3.
For example, when the lengths of the first link 2 and the second link 3 are shortened, the intersection angle θ becomes close to zero, and eventually the axes of the first link 2 and the second link 3 become on a straight line. In this case, since the axial component force P ₂ of the third link 4 also approaches zero, the rotational torque of the drive body 1
Even if T ₁ is increased, the link mechanism remains constrained and cannot operate.

However, since the intersection angle θ cannot be set large due to various restrictions, it is required that the pitch between the supporting points of the first link 2 and the second link 3 be accurate. However, since the pitch between the fulcrums cannot be avoided to some extent due to manufacturing constraints, in extreme cases the link mechanism may become inoperable as described above.

The present invention was made to solve the above-mentioned problems, and FIG. 3 shows an embodiment for smooth initial movement of the link mechanism.

According to this, the second link 3 is provided with a spring 8 such as a torsion coil spring that biases it in the direction of rotation, thereby counteracting the frictional resistance at the time of initial movement between the first link 2 and the second link 3. This gives it a winning initial torque. As a result, as the intersection angle θ decreases due to processing error between the first link 2 and the second link 3, the third
It is possible to compensate for fluctuations in the axial component force P ₂ of the link 4, and by setting the optimum torsion moment to act on the spring 8, smooth initial movement of the link mechanism can be expected.

As described above, according to the present invention, by energizing the spring to give initial motion torque to the second link, the initial motion of the link mechanism can be performed smoothly and reliably. Sufficient operation can be achieved without requiring much precision in link processing.

[Brief explanation of the drawing]

FIG. 1 is a front view of the link mechanism, FIG. 2 is a vector diagram of the link mechanism in a locked state, and FIG. 3 is a partial front view showing an embodiment of the link mechanism of the present invention equipped with a spring in a locked state. . 1...Driver, 2...First link, 3...Second link, 4...Third link, 8...Spring.

Claims (1)

[Scope of utility model registration request] In a link mechanism having a first link and a second link that is supported by the first link and rotates, the second link is rotated to provide an initial torque that overcomes the frictional resistance at the time of initial motion. A link mechanism characterized by having a spring that biases in a direction.