JPH0135528Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a locking structure for a box and its cover.

[Industrial Application Fields] [Prior Art] Conventionally, the locking structure between various boxes such as connector boxes, relay boxes, junction boxes, etc. used for electrical wiring in automobiles and their covers is shown in Figs. 7 and 8. The structure is as shown in the perspective view.

That is, 1 is a box, 2 is a cover thereof, a window 3 is opened in the cover 2, and a first flexible locking arm 4 is provided in the window 3 extending obliquely upward from the bottom of the inner wall 3a. On the other hand, a second locking arm 6 having a hook 5 at its tip is protruded from the box 1 facing the window 3 of the cover 2.
is made of a material that is sufficiently rigid compared to the first flexible locking arm 4.

Therefore, when attaching the cover 2 to the box 1, the locking arm 6 of the box 1 is attached to the window 3 of the cover 2.
The flexible locking arm 4 enters the interior while bending toward the inner wall 3a, and when the hook 5 of the locking arm 6 passes the tip of the locking arm 4, the locking arm 4 moves past the tip of the hook 5. It elastically returns to the lower surface and is engaged and locked with the second locking arm 6.

However, in such a conventional locking structure, since the thickness dimension a of the cover 2 is usually small, the height b of the first locking arm 4 is also small, and the engagement force between the locking arms is small. Therefore, the plate thickness c of the first locking arm 4 is also formed thin.

[Problem that the invention attempts to solve]

Therefore, when the cover 2 is attached to the box 1 and the locking arms are engaged and locked, the locking sound is small, making it difficult to confirm whether or not the locking arms are completely engaged. The disadvantage is that the engagement force between the arms is weak.

The present invention was developed by focusing on the drawbacks of the conventional box and cover locking structure.The locking arms have a strong mutual engagement force, and the locking sound when engaged is high, making it easy to confirm that the locking is engaged. It is an object of the present invention to provide a locking structure for a box and a cover, which is possible and requires less force for engagement of locking arms with each other.

[Means for solving problems]

1 to 3 show an embodiment of the present invention,
Figure 1 is an overall perspective view of the locking structure, Figure 2a is a locking arm installed on the cover, b is a perspective view of a locking arm installed on the box, and Figure 3 is a locking arm installed on the box. , a shows its side view, b shows its front view, and c shows its plan view.

In the figure, a window 3 is opened in the cover 2 of the box 1, and a first flexible locking arm 4 is provided obliquely upward from the bottom of the inner wall 3a.
A second locking arm 6 facing the window 3 of the cover 2 and having a hook 5 at its tip is protrudingly provided, and when the cover 2 is attached to the box 1, the first flexible locking arm 6 The locking structure is similar to the conventional locking structure in which the second locking arm 6 is engaged with the locking arm 4, but in the present invention, the second locking arm 6 is inserted into the second locking arm 6. Upright pieces 7 are fixedly formed on both ends of the first flexible locking arm 4 and the bottom wall 3b of the window 3, and the front end surface 5a of the hook 5 of the second locking arm 6 is shaped like an arc. It is formed into a convex surface.

The details of the second locking arm 6 are as shown in FIG. It is formed in a width that can be sufficiently engaged with the distal end surface 4a of the flexible locking arm 4. Furthermore, if the lower surface 5b of the hooking claw 5 is formed to be concave and the tip end surface 4a of the first locking arm 4 is formed to be convex, the engagement will be in close contact as shown in FIG. This prevents wobbling.

[Effect]

Next, the operation of the present invention having the above configuration will be explained. That is, when the cover 2 is attached to the box 1, when the locking arm 6 of the box 1 is inserted into the opening of the window 3, the front end of the hook 5 of the second locking arm 6 is inserted as shown in FIG. Since the surface is formed into an arcuate convex surface, the hooking pawl 5 initially comes into contact with the first flexible locking arm 4 at point m. Further, while pressing and bending the first flexible locking arm 4, the second flexible locking arm 4 is
When the locking arm 6 is inserted, both ends of the locking arm 4 are fixed by the upright pieces 7 fixed to the bottom wall 3b, so the locking arm 4 is inserted as shown in FIG. 4b. It becomes a double-sided flexible arm with a length l, and bends in an arc while slidingly contacting the arc-shaped convex surface of the front end surface 5a of the hooking claw 5 of the second locking arm. And the hooking claw 5 is the locking arm 4
At the same time as it gets over the tip of the locking arm 4, the end surface 4a of the locking arm 4 elastically returns along the lower surface 5b of the corresponding hooking claw 5, and as shown in FIG.
The distal end surface of the flexible locking arm 4 is closely aligned with the lower surface of the catch pawl 5 of the second locking arm 6 of the box 1 to achieve an engagement lock. In this case, the locking arm 4 becomes a flexible arm with both ends fixed by the upright pieces 7, so that the return elastic force is strong.

Furthermore, although the height d of the locking arm 4 is regulated by the thickness of the cover 2, the length 1 can be made sufficiently longer than the height d since there is no restriction in the width direction.
This makes it possible to reduce the pressing force required to deflect the locking arm 4. Furthermore, since the first flexible locking arm 4 is reinforced by the upright piece 7, it is possible to increase its fracture resistance.

[Other Examples]

FIG. 6 is a perspective view showing another embodiment of the locking structure for the cover 2 of the present invention.

In this embodiment, the upstanding pieces 7 fixed to both ends of the first flexible locking arm 4 and the bottom wall 3b of the window 3 are attached to the bottom wall 3b.
b, and the breaking strength of the locking arm 4 is further increased compared to the previous embodiment. In this embodiment, when the locking arm 4 is engaged with the second locking arm 6, the locking arm 4 bulges into the space S as shown by the broken line, and the function of the upright piece 7 is as described above. This is exactly the same as in the embodiment, and the pressing force does not increase.

[Effect of idea]

As explained above, according to the present invention, since the upright pieces are fixed at both ends of the first flexible locking arm provided on the cover, the locking arm becomes a double-sided flexible arm and has elasticity. It has a strong return force, and the second
A sense of moderation occurs when the locking arm is engaged with the locking arm.
The locking sound becomes louder, making it easier to confirm that the lock is locked, and at the same time, the engagement force itself is strengthened.

Furthermore, since the front end surface of the hooking claw of the second locking arm is formed into an arcuate convex surface, the first flexible locking arm is sufficiently long, and the hook can be held smoothly with a small force. It has advantages such as being able to engage and lock.

[Brief explanation of drawings]

Fig. 1 is an overall perspective view of the box-cover locking structure of the present invention, Fig. 2a is a perspective view of a locking arm provided on the cover constituting the locking structure of the present invention;
Figure b is a perspective view of the locking arm provided on the box.
Figure 3a is a side view of the locking arm according to the present invention provided on the box, Figure 3b is a front view of the same, Figure 3c is a plan view of the same, and Figure 4a is the locking structure of the present invention. Fig. 4b is a plan view of the same, Fig. 5a is a cross-sectional view explaining the action of
5B is a plan view of the locking structure of the present invention, FIG. 6 is a perspective view of the locking arm of the present invention provided on the cover, and FIG. 7 is a conventional locking structure. Fig. 8a is a perspective view of a conventional locking arm provided on the cover;
FIG. 8b shows a perspective view of a conventional locking arm provided on a box. 1...Box, 2...Cover, 3...Window, 4
...First flexible locking arm, 5... Hooking claw, 6...
Second locking arm, 7... standing piece.

Claims (1)

[Scope of utility model registration request] A window is opened in the cover of the box, a first flexible locking arm extending upwardly is provided in the window, and a second locking arm facing the window and having a hooking claw at the tip thereof is provided in the box. A locking structure in which the second locking arm is engaged with the first flexible locking arm by providing a locking structure,
Upright pieces are fixed to both ends of the first flexible locking arm and the bottom wall of the window, and the front end surface of the hook of the second locking arm is formed into an arcuate convex surface. The box and cover locking structure is characterized by: