JPS6248087B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a nut loosening prevention mechanism.

An example of a conventional nut loosening mechanism is the one shown on page 203 of "Nissan Laurel Maintenance Manual" published by Nissan Motor Co., Ltd. in November 1981. This is illustrated in the configuration shown in FIGS. 1 and 2. That is, 1 in the figure is a shaft, and a male thread 1a is provided on one side of this shaft 1, and a communication hole 1b that penetrates this shaft 1 in the radial direction is formed in the male thread 1a. be. Also,
On the right side of the shaft 1 in FIG.
It penetrates inside and protrudes to one side of the object 2 to be fastened. The object to be fastened 2 is attached to the protruding portion of the shaft 1.
A nut 4 is screwed together with a washer 3 interposed between them.

In addition, 5 in the figure is a cap, and this cap 5 is a cap body 5a having a hole in the center.
and a plurality of axially extending protrusions 5b continuous with the inner edge of the cap body 5a and provided at equal intervals in the circumferential direction.
An engagement hole 5c matching the outer shape of the nut 4 is formed on the opposite side of the nut 4 from the projection 5b. The cap 5 has its engagement hole 5c fitted into the nut 4, and the cotter pin 6 is inserted between the communication hole 1b of the shaft 1 and the respective protrusions 5b located on both sides of the communication hole 1b. Movement of the nut 4 in the axial direction is restricted to prevent the nut 4 from rotating. The parts of the cotter pin 6 protruding from both sides of the communication hole 1b have a locking part 6a formed by bending in advance, and a locking part formed by bending after inserting into the communication hole 1b. 6b are provided respectively, thereby preventing the split pin 6 from coming off.

However, in such a conventional nut loosening mechanism, the communication hole 1b provided in the shaft 1
The rotation of the cap 5 is restricted by matching the gaps between the protrusions 5b provided on the cap 5, and the cotter pins 6 are provided passing through the communication holes 1b and the gaps between the protrusions 5b. The structure was designed to prevent rotation of No. 4, that is, loosening. Therefore, the fixing position of the cap 5 in the circumferential direction can only be set in stages, and the rotation of the nut 4 is not actively inhibited.
Therefore, if the split pin 6 is not sufficiently bent or the pitch of the screw is large, the gap between the cap 5 and the nut 4 cannot be absorbed, etc. Nut 4 due to vibration etc.
There was a problem in that the nut 4 and the cap 5 became loose, which caused abnormal sounds such as tapping sounds to be generated between the nut 4 and the cap 5.

The present invention has been made by focusing on such conventional problems, and includes a shaft having a male thread and a communicating hole formed in the male thread portion and penetrating in the radial direction; A nut that is screwed onto this shaft, a bottom that has a hole through which the shaft is inserted and forms a plane perpendicular to the shaft, and that extends from the outer periphery of this bottom toward the nut in the axial direction and can come into contact with the tightening side of the nut. a locking wall, and a plurality of protrusions extending circumferentially from the edge of the hole at the bottom in the axial direction to the opposite side of the nut; a bottom of the cap and a head of the nut; an elastic body that is compressed in the axial direction and interposed therebetween; and a portion that is inserted between the communication hole of the shaft and the respective protrusions located on both sides of the communication hole, and that protrudes from both sides of the communication hole. The purpose of the present invention is to solve the above-mentioned problem by press-contacting the nut to the object to be tightened and actively inhibiting the rotation of the nut by forming a pin with a locking portion formed thereon. There is.

The present invention will be explained below based on the drawings.

FIG. 3 and FIG. 4 are diagrams showing an embodiment of the present invention.

First, to explain the configuration, 1 in the figure is the axis,
A male thread 1a is provided on one side of the shaft 1, and a communication hole 1b passing through the shaft 1 in the radial direction is formed in the male thread 1a. moreover,
A male thread (not shown) is provided on the right side of the shaft 1 in the figure, and this male thread part is similarly implanted in an item (not shown), and one male thread 1a side of the shaft 1 is tightened. It passes through the hole 2a of the object 2 and projects to one side of the object 2 to be fastened. 3 is a washer, 4 is a nut, and this nut 4 has a female thread that can be screwed into the male thread 1a of the shaft 1,
Moreover, its outer shape is hexagonal.

In addition, 5 in the figure is a cap, and this cap 5 has a cap main body 5a with a hole penetrated in the center part.
and a plurality of protrusions 5b that extend in the axial direction and are continuous with the inner edge of the cap body 5a and are provided at equal intervals in the circumferential direction. More specifically, the cap body 5a has a bottom portion 5 that is a plane perpendicular to the axis 1.
a-1, and a locking wall 5a-2 that extends from the outer periphery of the bottom portion 5a-1 toward the nut 4 in the axial direction and can come into contact with the tightening side surface 4a of the nut 4. On the opposite side of the cap body 5a from the protrusion 5b, an engagement hole 5c is formed by forming two holes that match the external shape of the nut 4 and are slightly displaced relative to each other in the direction of rotation. Reference numeral 7 denotes a ring-shaped elastic body made of rubber. 2. The outer diameter is formed so that it can fit into the engagement hole 5c formed inside. 6 is a split pin having a locking portion 6a formed on one side.

Next, the action will be explained.

This locking mechanism is assembled by loosely fitting the washer 3 onto the shaft 1, then screwing the female thread of the nut 4 onto the male thread 1a of the shaft 1, and using the nut 4 and an item (not shown). Start by tightening and fixing the object 2 to be tightened. At this time, it is confirmed that the communication hole 1b formed in the male thread 1a of the shaft 1 is exposed to the outside from the outer end surface of the nut 4.

Next, the elastic body 7 is inserted into the male thread 1a portion of the shaft 1, and the cap 5 is further inserted into the male thread 1 portion from the engagement hole 5c side. Then, when the cap 5 is pressed toward the nut 4 and the elastic body 7 is compressed between the bottom 5a-1 of the cap 5 and the head 4b of the nut 4 and elastically deformed, the elastic body 7 is positioned on both sides of the communication hole 1b. A cotter pin 6 is inserted into the communication hole 1b between the protrusions 5b from the side where the locking portion 6a is not formed, and the tip thereof is made to protrude outside the communication hole 1b. Thereafter, the sides of the split pins 6 on which the locking portions 6a are not formed are bent to opposite sides in the circumferential direction to form locking portions 6b.

Thus, since the elastic body 7 is in a compressed and deformed state, the restoring force of the elastic body 7 acts in the axial direction of the shaft 1, compressing the nut 4 toward the fastened object 2 side, and cracking the cap 5. Press it against the pin 6 side. Therefore, frictional force is generated on the contact surface between the nut 4 and the elastic body 7 and the contact surface between the elastic body 7 and the cap 5, respectively. In this state, if vibration is input to the shaft 1 or the clamped object 2 and a rotational force is applied to the cap 5, the frictional force generated between the cap 5 and the elastic body 7 The rotation of the cap 5 is prevented, or the elastic body 7 elastically deforms in the circumferential direction as the cap 5 rotates, thereby reducing the rotational force acting on the cap 5. Therefore, relative rotation between the cap 5 and the nut 4 is prevented, or even if both 4 and 5 rotate relative to each other, the rotational force thereof is buffered. Therefore, the impact between the nut 4 and the cap 5 is prevented, or the impact force is reduced, so that it is possible to prevent the generation of abnormal sounds such as hitting sounds.

In addition to the above-mentioned embodiments, for example, a taper pin or the like may be used as the pin inserted into the communication hole 1b to restrict the movement of the cap 5 in the axial direction.

FIGS. 5 and 6 show other embodiments of the invention.

In this embodiment, the elastic body 8 is vulcanized and adhered to the bottom of the engagement hole 5c of the cap 5, and the elastic body 8 is
The width of the nut 4 is increased so that when the cap 5 is assembled, a part of the elastic body 8 wraps around the tightening side surface 4a, which is the outer periphery of the nut 4.
The other configurations are the same as those in the previous embodiment. According to this, the elastic body 8 and the head 4b which is the end face of the nut 4
In addition to the frictional force between
The force to deform the cap 5 and nut 4
Because it acts as a force to suppress relative rotation with
Relative rotation between both 4 and 5 is more effectively prevented.

It is of course possible to use various known elastic members as the elastic bodies 7 and 8, such as spring washers and toothed washers, in addition to the embodiments described above.

As described above, the present invention includes a shaft having a male thread and a communicating hole formed in the male thread portion that penetrates in the radial direction, a nut screwed onto the shaft, and a nut screwed onto the shaft. a bottom portion having a hole through which the shaft is inserted and forming a plane perpendicular to the shaft; a locking wall extending from the outer periphery of the bottom portion toward the nut in the axial direction and capable of abutting against the tightening side of the nut; a plurality of protrusions each extending circumferentially from an edge toward the opposite side of the nut, and compressed in the axial direction between the bottom of the cap and the head of the nut; an intervening elastic body, a pin that is inserted between the communication hole of the shaft and the respective protrusions located on both sides of the communication hole, and has locking portions formed at portions protruding from both sides of the communication hole; The structure consists of the following. Therefore, the nut is always in pressure contact with the object to be tightened, and the cap is always in pressure contact with the pin.
Therefore, the nut can be prevented from loosening regardless of the mounting position of the nut with respect to the communication hole of the shaft. Furthermore, due to the frictional force between the nut, the cap, and the elastic body, and the elastic deformation of the elastic body, relative rotation between the cap and the nut can be prevented or the rotational force can be reduced. The effect is that it is possible to prevent the generation of abnormal noises such as impact sounds due to collisions with other objects.

[Brief explanation of the drawing]

1 and 2 show a conventional nut locking mechanism, FIG. 1 is a front view, FIG. 2 is a partially sectional right side view, and FIGS. 3 and 4 are views of one of the present invention. Fig. 3 is an exploded explanatory view, Fig. 4 is a partially cutaway right side view showing an assembled state, and Figs. 5 and 6 show other embodiments of the present invention. 5 is a sectional view of the cap,
FIG. 6 is a partially cutaway right side view showing the assembled state. 1...Shaft, 1a...Male thread, 1b...Communication hole, 2...Tightened object, 4...Nut, 4a...Tightening side, 4b...
Head, 5...Cap, 5a...Cap body, 5a
-1...bottom, 5a-2...locking wall, 5b...protrusion, 5
c...Engagement hole, 6...Cotter pin (pin), 6a, 6b...
Locking portion, 7, 8...elastic body.

Claims (1)

[Claims] 1. A shaft having a male thread and having a communication hole formed in the male thread portion and penetrating in the radial direction, a nut screwed onto the shaft, and a hole through which the shaft is inserted. a bottom part forming a plane perpendicular to , a locking wall extending from the outer periphery of the bottom part toward the nut in the axial direction and capable of abutting against the tightening side of the nut, and a locking wall extending from the edge of the hole in the bottom part in the axial direction along the circumferential direction. a plurality of protrusions extending toward the opposite side of the nut; an elastic body compressed in the axial direction between the bottom of the cap and the head of the nut; A nut comprising a communicating hole and a pin inserted between respective protrusions located on both sides of the communicating hole, and having locking portions formed at portions protruding from both sides of the communicating hole. Anti-loosening mechanism.