JPH083324B2 - Plate material connecting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a connecting device for a plate member including a screw pin and a grommet, and particularly to an improvement of the grommet.

<Prior Art> Conventionally, as a connecting device of this type, there has been an actual utility model sho 60-21537.
There is a gazette.

This conventional connecting device includes a pin having a head and a male screw portion that hangs from the lower surface of the head, a flange portion that faces the head of the pin, a leg portion that hangs from the lower surface of the collar portion, and a collar portion. And a grommet provided with an insertion hole into which the male screw portion of the pin communicating from the upper surface of the pin to the leg portion can be inserted. The pin and the grommet are integrally formed of plastic.

Then, in the leg portion of the grommet, a pair of vertical split grooves that extend radially around the insertion hole, and are respectively formed in the interval between both vertical split grooves, and each upper end is connected to the lower surface of the flange portion. , Each lower end is interconnected by a hinge portion, and has a pair of enlarged diameter portions that expand in diameter with the insertion of the male screw portion into the insertion hole, and each inner side surface of both enlarged diameter portions has a pin Two upper and lower hemispherical projections, which are fitted in the thread grooves of the male screw portion, are integrally formed to project.

<Problems to be Solved by the Invention> However, the above-described conventional coupling device has a problem in the pulling-out performance when the pin is rotated in the reverse screw direction.

That is, when connecting and fixing two plate members, the male screw portion of the pin is forced into the insertion hole of the grommet to expand the enlarged diameter portion of the grommet. When releasing the connected and fixed state of both plate members, the pin may be rotated in the reverse screw direction. By this rotation in the reverse screw direction, the hemispherical protrusion in the grommet insertion hole traces the thread groove of the male screw part of the pin, so that the male screw part of the pin moves backward in the grommet insertion hole and is relatively opposed to the grommet. You can get out of it.

However, since the protrusion in the insertion hole of the grommet is hemispherical, the amount of meshing with the thread groove of the male thread portion of the pin is small. Therefore, when the pin is rotated, a force that pushes the grommet into the insertion hole is applied, so that the projection easily gets over the thread.

Therefore, the male screw portion of the pin may be in an idling state in the grommet insertion hole, and the pin may not easily come off. In particular, when the pin is rapidly rotated using an electric tool, this idling state is likely to occur, which is unsuitable for removing work using the electric tool.

<Means for Solving the Problems> Therefore, the present invention is to solve the above problems, and a pin provided with a head and a male screw part hanging from the lower surface of the head and a head of the pin are opposed to each other. The grommet includes a collar portion and a leg portion that hangs from the lower surface of the collar portion, and a grommet having an insertion hole into which the male screw portion of the pin that communicates with the leg portion from the upper surface of the collar portion can be inserted. Are formed in a plurality of vertical split grooves that extend radially around the insertion hole, and are respectively formed in the intervals of the vertical split grooves, and each upper end is connected to the lower surface of the collar portion and each lower end is mutually connected by the hinge portion. Connected to
The inside of the insertion hole has a taper surface that reduces the inside diameter of the insertion hole, and the inside of the insertion hole has a plurality of enlarged diameter portions that expand in diameter as the male screw portion is inserted into the insertion hole. A ridge forming a part of a spiral shape that fits into the thread groove of the male thread portion of the pin is formed in the middle of the ridge, and the enlarged diameter portion is formed on the outer surface of each enlarged diameter portion provided on the leg portion of the grommet. It is characterized in that a vertical groove having a V-shaped cross-section is provided to facilitate bending.

<Examples> The present invention will be described below based on examples shown in the drawings.

In the figure, reference numeral 1 denotes a connecting device, and the connecting device 1 includes a head 4 and a pin 4 provided with a male screw portion 3 hanging from a lower surface of the head 2, and a collar facing the head 2 of the pin 4. From the portion 5 and the leg portion 6 hanging from the lower surface of the collar portion 5, and the grommet 8 having the insertion hole 7 into which the male screw portion 3 of the pin 4 communicating with the leg portion 6 from the upper surface of the collar portion 5 can be inserted. The pin 4 and the grommet 8 are integrally formed of plastic.

As shown in FIG. 1, the pin 4 has a head 2 having a thin disk-shaped seat portion 9, a bolt-shaped bolt portion 10 protruding from the upper surface of the seat portion 9, and a bolt portion 10 of the bolt portion 10. It is provided with a + -shaped driver groove 11 into which a cutting edge of a driver (not shown) formed in a recess at the center of the upper surface is inserted. The head 2 may be provided with only one of the bolt portion 10 and the driver groove 11, and the driver groove 11 may be a − groove instead of a + groove.

Similarly, as shown in FIG. 1, the male screw portion 3 has a shaft shape that hangs down from the center of the lower surface of the seat portion 9 and has a tapered tip, and has a semicircular cross-section projecting on its peripheral surface. Screw thread 12
And a thread groove 13 formed within the space between the threads 12. The shape and material of the pin 4 are not limited to those of the embodiment shown in the drawings, and metal bolts, screws, etc. may be used as they are.

Next, in the grommet 8, as shown in FIGS. 2 to 6, the collar portion 5 forms an annular shape slightly larger than the seat portion 9 of the pin 4, and the seat portion 9 is easily attached to the upper surface thereof. A shallow annular recess 14 centered on the insertion hole 7 to be fitted is provided.

Further, the leg portions 6 are formed in a plurality of radially extending grooves 15 centering on the insertion hole 7 and four vertical dividing grooves 15 ... In the space between the vertical dividing grooves 15, and the upper ends of the leg portions 6 are provided with a collar. While being connected to the lower surface of the portion 5, each lower end is connected to each other by a hinge portion 16, and has a plurality of four diameter-increasing portions 17 ... Which expand in diameter when the male screw portion 3 is inserted into the insertion hole 7. It will be done.

The enlarged diameter portion 17 has a tip which is gradually narrowed to reach the hinge portion 16, and a tapered surface 18 inclined like a mortar that reduces the inner diameter of the insertion hole 7 is formed on the inner side surface thereof, and the outer side surface thereof. Forms a vertical groove 19 having a V-shaped cross section for facilitating bending of the expanded diameter portion 17.

The hinge portion 16 has a thin rod shape, and each upper end thereof is connected to a tapered tip portion of each expanded diameter portion 17 and each lower end thereof is connected to a circular bottom portion 20 serving as a bottom of the insertion hole 7. Part 16 is the bottom
Connected to each other via 20.

On the other hand, in the insertion hole 7, the pin 4 is inserted in the middle of its height.
The projecting ridges 21 forming a part of a spiral shape to be fitted into the thread grooves 13 of the male screw part 3 of are formed. In this case, the ridge 21 has a semicircular cross section, and both end portions 21 ', 21 "are vertically and stepwise staggered to each other, and are continuous in a spiral shape connected to about one ridge. A plurality of protrusions 21 may be formed similarly to the thread groove 13.

Next, in order to connect and fix the two plate members 22 and 23 in a superposed state by using the pin 4 and the grommet 8 having the above-described configuration, first, the both plate members 22 and 23 are shown in FIGS. Similarly, circular mounting holes 24 and 25, which are substantially equal to or slightly larger than the outer diameter of the leg 6 through which the leg 6 of the grommet 8 passes, are provided.

On the other hand, the pin 4 and the grommet 8 may be combined when connecting both plate members 22 and 23, but in this case, the male screw part 3 of the pin 4 is inserted into the insertion hole 7 of the grommet 8 in order to simplify the handling. Put it as a temporary combination state that is shallowly inserted.

That is, when the male screw portion 3 of the pin 4 is inserted, the male screw portion 3
The thread 12 and the protrusion 21 protruding into the insertion hole 7 come into contact. When the pin 4 is strongly pushed in here, both cross sections of the thread 12 and the ridge 21 form a semicircle, so that the thread 12 twists the ridge 21 to slightly expand the insertion hole 7. Meanwhile, it goes over the ridge 21 and advances into the insertion hole 7. Then, the thread 12 is the protrusion 21.
When it gets over, the insertion hole 7 returns to the original diameter due to the elastic restoring force of the expanded diameter portion 17 or the like around the insertion hole 7, and at this time, the protrusion 21
Snaps into the thread groove 13 on the thread 12, and the male screw part 3 is held in a state of being shallowly inserted into the insertion hole 7 (FIG. 7).

In this inserted state, since the male screw part 3 has not reached the taper surface 18 of the expanded diameter part 17, the expanded diameter part 17 maintains its original diameter without expanding its diameter.

Next, as shown in FIG. 7, the two plate members 22 and 23 are vertically overlapped with each other so that the mounting holes 24 and 25 are aligned with each other, and the grommet 8 is inserted into the aligned mounting holes 24 and 25. The leg parts 6 of the grommet 8 are inserted in series, and the lower surface of the collar part 5 of the grommet 8 is an upper plate material.
The head 2 of the pin 4 may be strongly pushed into the grommet 8 at the position where it hits the upper surface of 22.

As a result, the screw threads 12 pass over the ridges 21 one after another, and penetrate into the insertion hole 7, and the screw threads 12 contact the tapered surface 18. Since the inner diameter of the insertion hole 7 is narrower than the outer diameter of the male screw portion 3 by the tapered surface 18, if the male screw portion 3 of the pinch is forced into the small diameter space 26,
The taper surface 18 of the inner surface of the expanded diameter portion 17 is pushed outward in the radial direction by the screw thread 12, and the expanded diameter portion 17 is connected to the lower surface of the collar portion 5 by a connecting portion 17 '.
And bulging outward from the hinge portion 16 in the radial direction under the lower plate member 23, and sandwiching both plate members 22 and 23 from the upper and lower sides with the lower surface of the collar unit 5 so that both plate members 22 and 23 are in a superposed state. Connect and fix (Fig. 8). The force required to push the male screw portion 3 and inflate the expanded diameter portion 17 outward is that the outer surface of the expanded diameter portion is provided with a vertical groove 19 having a V-shaped cross section so that it can be easily bent. The expanded diameter portion can be easily inflated without the need.

The pushing limit of the pin 4 is regulated at the position where the lower surface of the seat 9 contacts the upper surface of the annular recess 14 of the grommet 8. In this state, the seat 9 fits into the annular recess 14 with a suppon. Fit in the state.

Next, at the time of maintenance or the like, when it becomes necessary to separate the two plate members 22, 23, the head 2 of the pin 4 may be rotated in the reverse screw direction.

At this time, since the head portion 2 of the pin 4 is provided with the bolt portion 10 and the driver groove 11, the bolt portion 10 may be turned with a spanner, a box wrench, or the like, or the driver's cutting edge is inserted into the driver groove 11. You may turn it.

Thus, when the head 2 of the pin 4 is rotated in the reverse screw direction, the protrusion 21 fitted in the screw groove 13 traces the screw groove 13 so that the male screw portion 3 moves backward in the insertion hole 7. , Gradually come out. Therefore, the expanded diameter portion 17 is reduced in diameter under the plate member 23 below due to its elastic restoring force, and is restored to the original diameter.

Therefore, the leg portion 6 of the grommet 8 has a diameter that allows it to be pulled out from both the mounting holes 24 and 25, so that the superposed fixed state of the two plate members 22 and 23 is released and the two plate members 22 and 23 can be separated.

Then, the grommet 8 can be recovered by pulling it upward from both mounting holes 24, 25.

On the other hand, when the expanded portion 17 is restored, the hinge portions 16
The hinge portion 16 restores the hinge portion 16 while uniformly pulling it inward in the radial direction. For this reason,
It is possible to reuse the recovered material without causing the expanded diameter portion 17 to be plastically deformed and to be expanded and not restored.

On the other hand, FIGS. 9 to 22 show a second embodiment of the coupling device 1, the structure of which will be described below. In the description, the same structure as that of the first embodiment described above will be used. The same reference numerals are given to the parts, and the description thereof will be partially omitted.

As shown in FIGS. 10 to 14, the pin 4 of the present embodiment has a relatively thin head portion 2 and is provided with only a driver groove 11 for inserting a cutting edge of a driver (not shown) in the center of its upper surface. There is.
Further, the male screw portion 3 is provided with a long hole 27 extending in the axial direction and penetrating in the front-rear direction in the middle of its height.

On the other hand, as shown in FIGS. 15 to 19, the grommets 8 extend radially around the flange 5 in four directions centered on the insertion holes 7 which are respectively connected to the four vertical grooves 15 of the leg 6. In addition, four notches 28 are provided on the upper surface. Further, the annular recess 14 of the collar portion 5 is sized so that the head portion 2 of the pin 4 fits into the snap ring, and the male screw portion 3 of the pin 4 is completely inserted into the insertion hole 7. The upper surface of 2 is flush.

The ridge 21 is formed so as to extend from the thickness of the collar portion 5 to the inner side surface of the enlarged diameter portion 17, and the middle of the length thereof is provided with the cutout portion 28 and the vertical split groove.
Each ridge 21a divided by 15 and divided into four
21 d are arranged so as to form a part of a spiral shape. As shown in FIG. 19, the upper end 21a 'of the upper protrusion 21a and the lower end 21d' of the lower protrusion 21d face each other vertically with a vertical groove 15 interposed therebetween.

As shown in FIG. 23, the upper end 21 and the lower end 21 of the ridge 21 are
′ And ′ may be made to cross up and down differently in the same plane of the inner surface of the expanded diameter portion 17.

According to the second embodiment, the male screw portion 3 of the pin 4 has an elongated hole 27.
Since the screw thread 12 is pushed by the ridge 21 when riding over the ridge 21, the outer diameter of the male screw part 3 is slightly reduced. At the same time, since the grommet 8 has the notch 28, when the ridge 21 is pushed by the screw thread 12, the inner diameter of the opening of the insertion hole 7 increases. Therefore, due to the synergistic effect of the two, the screw thread 12 and the ridge 21 may move while moving in the directions away from each other, so that not only the inserting force of the pin 4 can be reduced but also the thread 12 and the ridge 21 can be reduced. It is possible to prevent crushing.

Either one of the pin 4 and the grommet 8 of the first embodiment may be used in combination with one of the pin 4 and the grommet 8 of the second embodiment.

Further, by providing the notch 28 in the collar 5, there is an advantage that the protrusion amount of the protrusion 21 at the time of molding can be increased.

This will be described with reference to FIG. 22 which shows a mold for forming the grommet 8. In FIG. 22, 29 is one fixed mold,
Reference numeral 30 is a protruding pin of a molded product, 31 is a male core pin that forms the insertion hole 7 of the grommet 8, and 32 is a recess for forming the protrusion 21 of the grommet 8 that is provided on the outer periphery of the core pin 31. Show.

Then, at the time of molding the grommet 8, a fixed mold 29 and a movable mold (not shown) are butted against each other and clamped, and then a molten raw material is injected. Next, the movable mold is moved to open the mold, and after completion of the mold opening, the molded product is projected by the projecting pin 30 and released from the fixed mold 29. At this time, the core pin 31 is forcibly removed at the same time, so that the protrusion 21
Is formed.

Therefore, in order to increase the amount of protrusion of the protrusion 21, the core pin
It is necessary to increase the depth of the recess 32 of the core pin 31.
It becomes difficult to remove 31 by force, and the mold cannot be released or the molded product is easily distorted. So, in general, the core pin
Although the mold release is possible by making the recess 32 of the groove 31 shallow, there is a problem that the protrusion amount of the protrusion 21 cannot be increased.

On the other hand, in the second embodiment, the notch 28 is formed in the collar 5.
By providing the, when the core pin 31 is forcibly removed,
Since the diameter of the insertion hole 7 is expanded from the cutout portion 28 and the vertical dividing groove 15, the mold release is easier than that without the cutout portion 28. Therefore, there is an advantage that the recessed portion 32 of the core pin 31 can be deepened correspondingly and the protrusion amount of the protrusion 21 can be increased.

Therefore, the amount of engagement between the protrusion 21 and the male screw portion 3 of the pin 4 can be further increased, and even when the pin 4 does not rotate idly even when the pin is rotated rapidly by using the electric screwdriver, the removal using the electric screwdriver can be prevented. The connection device 1 suitable for workability can be provided.

<Effects of the Invention> As described above, according to the present invention, since the protrusion that forms a part of the spiral shape and the thread groove of the male screw part have complementary shapes to each other, when the pin is rotated in the reverse screw direction. Moreover, there is no idling, and the spiral shapes of both sides wait for each other to improve the climbing performance. Further, since a vertical groove having a V-shaped cross-section is provided on the outer surface of each expanded diameter portion provided on the leg portion of the grommet to facilitate bending of the expanded diameter portion, a plurality of plate members can be connected and fixed. Further, pushing the male screw portion of the pin into the insertion hole of the grommet to inflate the expanded diameter portion outward can be easily performed without requiring a large force.

[Brief description of drawings]

The drawings show an embodiment of the present invention, and FIGS.
1 shows an embodiment, FIG. 1 is an exploded perspective view, FIG. 2 is a side view of a grommet, FIG. 3 is the same plan view, FIG. 4 is the same bottom view, and FIG. 5 is A- of FIG. A sectional view taken along line A, FIG. 6 is a sectional view taken along line BB of FIG. 3, FIG. 7 is a sectional view for explaining a procedure for attaching the connecting device to both plate members, and FIG. Sectional views showing a connected state of both plate materials, FIGS. 9 to 22 show a second embodiment, FIG. 9 is an exploded perspective view, FIG. 10 is a front view of a pin, and FIG. 11 is a side view of the same. FIG. 12 is the same plan view,
13 is a bottom view of the same, FIG. 14 is a sectional view taken along the line CC of FIG. 12, FIG. 15 is a side view of the grommet, FIG. 16 is a plan view of the same, and FIG. 17 is a bottom view of the same. FIG. 18 is a sectional view taken along the line DD of FIG. 16, FIG. 19 is a sectional view taken along the line E-E of FIG. 16, and FIG. 20 explains the procedure for attaching the connecting device to both plate members. FIG. 21 is a sectional view showing a connecting state of both plate materials, FIG. 22 is a sectional view showing a mold for forming a grommet,
FIG. 23 is a sectional view showing another embodiment of the grommet. In the figure, 1 is a connecting device, 2 is a head part, 3 is a male screw part, 4 is a pin, 5 is a flange part, 6 is a leg part, 7 is an insertion hole, 8 is a grommet, 13 is a screw groove, and 15 is a vertical direction. Split grooves, 16 are hinge portions, 17 is an enlarged diameter portion, 19 is a vertical groove having a V-shaped cross section, 22 and 23 are plate members, and 24 and 25 are their respective mounting holes.

Claims (1)

[Claims] 1. A pin having a head portion and a male screw portion hanging from the lower surface of the head portion, a flange portion facing the head portion of the pin, a leg portion hanging from the lower surface of the collar portion, and an upper surface of the collar portion. From a grommet having an insertion hole into which the male screw part of the pin communicating with the leg part can be inserted, and in the leg part of the grommet, a plurality of vertical split grooves extending radially around the insertion hole, Each upper end is connected to the lower surface of the flange, and each lower end is connected to each other by a hinge, and the inside has a tapered surface that reduces the inner diameter of the insertion hole downward. And a plurality of diameter-increasing portions that expand in diameter with the insertion of the male screw portion into the insertion hole, and the spiral that fits into the thread groove of the male screw portion of the pin in the height of the insertion hole. Formed on the leg of the grommet, forming a ridge that forms part of the shape The outer surface of the enlarged diameter portion, the coupling device of the plate material, characterized in that a longitudinal groove of V-shaped cross section for facilitating flexing of the enlarged diameter portion.