JP6810520B2 - Fastening device - Google Patents

Description

The present invention relates to a fastening device including metal fittings and screws. Here, the metal fitting is a general term for members that are pressed and fixed to the base material with screws, and the size and shape do not matter. In addition to those used for specific purposes, it also includes washers as general-purpose products.

It is widely practiced to fix various members (workpieces) such as plate materials and frame materials to a base material with screws. One problem in this case is that when the base material is a soft or brittle material such as wood, concrete such as ALC, or brick, the female screw of the base material is crushed and fastened due to excessive screwing. The stripping phenomenon that makes it impossible is likely to occur. An electric screwdriver is generally used for screwing a screw, but in recent years, an electric screwdriver has improved performance and a high torque, so that the screwdriver is screwed too much and a stripping phenomenon is likely to occur.

Therefore, it is considered to prevent the screw from being screwed in too much. As an example, in Patent Documents 1 and 2, while providing a protrusion on the seating surface of the head of the screw, the head of the screw among the workpieces fixed by the screw It is disclosed that a groove is formed in a portion where the seating surfaces of the screws overlap, and the rotation of the screw is stopped by fitting the protrusion of the screw into the groove of the work as the screw is screwed.

Japanese Unexamined Patent Publication No. 2003-194027 Japanese Unexamined Patent Publication No. 60-26807

In Patent Documents 1 and 2, the screwing of the screw is automatically stopped, but there are some problems. For example, since the groove of the work has a bottom surface and is only open to the front surface side , the protrusion fits into the groove before the work is strongly pressed by the head of the screw, and the work is fastened. The strength may be insufficient. Further, since the groove processing is very troublesome, it can hardly be applied to a work made of a thin metal plate, and therefore, it must be said that it lacks versatility.

The invention of the present application has been made to improve the present situation in this way.

The present invention relates to a fastening device including a metal fitting that overlaps the base material and a screw that fixes the metal fitting to the base material.
"It consists of a metal fitting that overlaps the base material and a screw that fixes the metal fitting to the base material.
The screw is a countersunk screw having a tapered head seat surface, and a plurality of engaging protrusions extending in the radial direction when viewed from the axial direction are formed on the head seat surface apart from each other in the circumferential direction. On the other hand
The metal fitting is formed with a screw insertion hole through which the shaft of the screw passes and an annular protrusion having a tapered receiving seat on which the seating surface of the head of the screw overlaps, and the tip of the metal fitting is formed on the receiving seat of the annular protrusion. A plurality of engaging grooves extending in the radial direction are formed apart in the circumferential direction while opening in the screw insertion hole.
The portion sandwiched between the adjacent engaging grooves becomes a tongue-shaped piece having the tip facing the screw insertion hole as a free end, and the tongue- shaped piece is deformed so that the engaging projection fits into the engaging groove. The rotation of the screw is regulated by turning. "
It is a basic configuration.

Then, in the invention of claim 1, in the above basic configuration,
"The engaging protrusion has a double-sided tapered shape in which both the side surface facing the screwing direction and the side surface facing the screwing back direction are inclined so as to narrow in the radial direction when viewed from the axial direction. , While set to the same width and height over the entire length
The tongue-shaped piece extends to the outside of the head of the screw by allowing the base end of the engaging groove to extend beyond the receiving seat to at least the top surface of the annular projection. "
It has the feature. In the present invention, it can be said that many metal fittings are metal products such as processed sheet metal products, but resin products are not excluded.

The invention of the present application can be developed in various ways. An example is specified in claim 2 and below. Of these, the invention of claim 2 is claimed in claim 1 .
"At least the free end of each tongue-shaped piece is inclined so that the front side is low and the front side is high toward the screwing rotation direction of the screw, so that there is a step between adjacent tongue-shaped pieces. Is formed "
It is configured as.

As an example of the specific configuration of claim 2 , in claim 3 , the number of the tongue-shaped pieces is N, the pitch of the screws is P, and the maximum dimension of the step between the adjacent tongue-shaped pieces is E. Then, while the relationship is E> (P / N), the protrusion dimension of the engaging protrusion from the seat surface is smaller than or equal to the thickness dimension of the tongue-shaped piece.

The fastening device of the present invention can be applied to various uses, but the invention of claim 4 is the invention of any one of claims 1 to 3.
" A stud bolt for fixing the solar panel is projected from the metal fitting, the receiving seat is formed around the stud bolt, and the frame material forming the outer peripheral portion of the solar panel is the stud bolt. It is set to be fitted into and fixed with a nut. "
It is configured as.

When screwing a screw with a power tool such as an electric tool, in the present invention, when the seating surface of the screw reaches a state where the metal fitting is strongly pressed, the engaging protrusion of the screw and the engaging groove of the metal fitting are fitted to each other. The rotation of the screw stops and strong resistance is generated in the power tool. Therefore, the operator only needs to release his finger from the trigger at that point, which allows the screw to be screwed to an appropriate depth. That is, screwing the screw to an appropriate depth can be performed almost automatically.

Therefore, in the present invention, the base material is a brittle material such as concrete such as ALC, ceramic or cement siding, brick, gypsum board, thin metal board, not thick wood board, or relatively thin resin board. Even if the material does not have high resistance to pulling out, it is possible to prevent over-driving of screws and prevent improper fastening of metal fittings.

In the present invention, since the metal fitting is formed with an engaging groove penetrating the front and back as a rotation regulating means, the tongue-shaped piece around the screw insertion hole of the metal fitting is pushed by the engaging protrusion and elastically deformed. It is possible, so the screw can be screwed in until the metal fitting is pressed firmly with its head. That is, the screw can be rotated while the engaging protrusion is in contact with the metal fitting.

As a result, the seating surface of the screw can be strongly applied to the receiving portion of the metal fitting in a state where the engaging protrusion of the screw is fitted in the engaging groove of the metal fitting, and high fastening strength can be ensured. In particular, when the metal fitting overlaps with a soft member, it is possible to ensure that the portion of the metal fitting around the screw insertion hole is elastically deformed, so that it is more reliable to secure the required fastening strength.

Further, since the engaging groove can be easily machined by punching, it can be easily applied to a metal fitting made of a thin metal plate. Therefore, it is excellent in versatility and has high practical value. Furthermore, loosening of the screw can be prevented. Since the engaging protrusions of the screws can be formed at the same time when the head is pressed by the header, there is no difficulty in processing.

Further, in the present invention, the tongue-like piece to become easily deformed they become state of the cantilever, made on improvement of pressing function of the receiving seat by the seat surface of the screw has an advantage of ensuring a high fastening strength ..

In the present invention, since the annular protrusion is formed on the metal fitting by applying the seat surface to a screw ( counterbore screw) formed in a tapered shape, the portion surrounded by the annular protrusion and the base material becomes a space. Since each tongue-shaped piece is more easily bent and deformed, it becomes easier to fit the engaging protrusion into the engaging groove.

By the way, the engaging protrusion of the screw hits the receiving seat of the metal fitting while rotating, but which part of the tongue-shaped piece the engaging protrusion first hits is not constant. That is, the engaging protrusions range from the state of hitting the start end of the tongue-shaped piece to the state of hitting the end of the tongue-shaped piece in the circumferential direction. It can be said that it fits into the engaging groove after rotating in a state of being in contact with (in a metal touch state).

Since the engaging protrusion protrudes from the seating surface, when the engaging protrusion hits the tongue-shaped piece, there is a gap between the seating surface of the screw and the tongue-shaped piece by the protruding dimension of the engaging protrusion. Vacant. Therefore, in order to firmly press the metal fittings with screws to secure a predetermined fastening strength, it is necessary for the seat surface to come into contact with the tongue-shaped piece while the engaging protrusions are fitted in the engaging grooves, and this state is realized. The bending deformation of the tongue-shaped piece is used for this purpose, but when the configuration of claim 2 is adopted, the tongue-shaped piece is formed in a so-called twisted state, so that the engaging protrusion of the screw is used. The tongue-shaped piece is pressed by the seating surface of the screw so as to untwist the twist, so that the tongue-shaped piece is strongly pressed by the seating surface of the screw to secure the specified fastening strength. It is more certain to do.

Further, as described above, the engaging protrusion of the screw is fitted in the engaging groove of the metal fitting to prevent the screw from loosening. However, when the tongue-shaped piece is deformed as in claim 2 , the tongue-shaped piece is deformed. The elastic restoring force of the piece keeps the tongue-shaped piece of the metal fitting pressed by the seating surface of the screw, so even if the work returns to the screw due to thermal expansion and contraction and the rotational force acts, the screw will loosen. There is also an advantage that can be prevented. In addition, loosening due to vibration can be prevented.

Further, in claim 2 , since a step is formed between the adjacent tongue-shaped pieces, for example, the position where the engaging protrusion of the screw first hits the receiving seat of the metal fitting is one tongue-shaped piece. Of these, when the portion is close to the end portion in the rotation direction of the screw, the engaging projection straddles the engaging groove and moves to the adjacent tongue-shaped piece.

In particular, when the configuration of claim 3 is adopted, it becomes easy for the engaging protrusion to straddle the engaging groove and move to the adjacent tongue-shaped piece, so that the engaging protrusion is fitted in the engaging groove. It can be said that it is more certain that the seat is firmly pressed by the seat surface.

As described above, when the engaging protrusion hits the receiving seat (tongue-shaped piece), there is a gap between the engaging protrusion and the receiving seat, and the gap is absorbed by the elastic deformation of the receiving seat. In order to strongly press the receiving seat of the metal fitting with the seating surface of the screw, it is preferable that the protruding dimension of the engaging protrusion is as small as possible. In this regard, as in claim 3 , when the protruding dimension of the engaging protrusion is made smaller than the plate thickness of the tongue-shaped piece (or the plate thickness of the metal fitting), the protruding dimension of the engaging protrusion is made as small as possible and the engaging protrusion is formed. Is suitable because it can prevent the work from coming into contact with the work.

In the present invention, since the engaging groove is formed in a state of being cut open to the outside of the receiving seat and the tongue-shaped piece extends to the outside of the head of the screw, the bending deformation of the receiving seat becomes easier . It is possible to further ensure that the screw is screwed to a predetermined depth . As a result, while maintaining a predetermined fastening strength to prevent screwing too far bis, is more reliable reduction.

In the figure which shows the 1st Embodiment, (A) is a perspective view of a construction part, (B) is a plan view of a screw, (C) is a front view of a screw, (D) is a DD view section of (C). (E) is a sectional view taken along line EE of (C), (F) is a partial plan view of a metal fitting, and (G) is a sectional view taken along line GG of (F). It is a figure which shows the screwing process, (A) is the cross-sectional view which shows the screwing process, (B) is the cross-sectional view in the state which it was screwed off, (C) is the CC view sectional view of (B). It is a figure which shows the 2nd Embodiment, (A) is a vertical sectional front view of the construction part in the middle of a fastening work, (B) is an operation explanatory view which each tongue-shaped piece is developed and displayed. It is a reference view which shows the state in which a loosening action acts on a screw by thermal expansion and contraction of a work, (A) is an overall plan view, and (B) is a schematic sectional view.

(1). Structure of Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to a fastening device for fixing a solar panel to a roof. As shown in FIG. 1 (A), in the roof, a beam material 1 made of lightweight H-shaped steel supports a roof plate 2 made of ALC, and a heat insulating material 3 and a waterproof sheet 4 are superposed on the roof plate 2. It has a basic structure.

The fastening device 5 is composed of a rectangular (rectangular) metal fitting 6 that overlaps the waterproof sheet 4 and four screws 7 that fix the metal fitting 6, and a stud bolt 8 is provided at the center of the metal fitting 6. A frame material constituting the outer peripheral portion of the solar panel (not shown) is fitted into the stud bolt 8 and fixed with a nut (not shown). Generally, the four corners of the solar panel are fixed by the fastening device 5. The four corners of the fittings 6 are spaced circle screw insertion hole 9 fitting bis 7, by screwing the screw 7 into the roof plate 2, fitting 6 is pressing secured. In the present embodiment, it can be said that the roof plate 2 made of ALC is used as a base material, and the metal fitting 6, the waterproof sheet 4, and the heat insulating material 3 are fixed to the base material by screws 7.

The screw 7 has a shaft 10 and a head 11 provided at one end thereof, and a single thread 12 is formed on the outer circumference of the shaft 10 (a multi-thread screw may be used). The thread 12 has a pitch P approximately the same as the valley diameter d, and the valley has a smooth surface on which the thread 12 does not exist. Further, the tip of the shaft 10 is sharp, and the screw thread 12 reaches the tip while gradually lowering the height. Therefore, the screw 7 is a wood screw type having self-perforation property. It should be noted that a part of the shaft 10 near the head 11 is a screwless portion having the same material diameter.

The head 11 of the screw 7 is a countersunk head having a tapered seat surface 13 whose diameter is reduced toward the shaft 10, and a cross-shaped engaging hole 14 into which a bit is fitted is formed on the top surface. The engaging hole 14 can be a quadrangle, a hexagon, a star, or the like.

On the seat surface 13 of the head 11, engaging protrusions (engaging ridges) 15 extending radially ( elongated in the axial direction ) when viewed from the axial direction are provided at equal intervals in the circumferential direction as a means for restricting rotation on the screw side. Four are formed. As is shown enlarged in FIG. 1 (E), in the engaging projection 15 , both the front side surface 15b facing the screwing direction and the rear side surface 15 facing the screwing back direction are opposite to each other when viewed from the axial direction. It has a trapezoidal shape with double-sided taper that is inclined to . Both side surfaces ( inclined surfaces ) 15a and 15b are formed symmetrically when viewed from the axial direction, and are inclined by θ1 with respect to the line X in the radial direction passing through the axial center , respectively. The cross-sectional shape of the engagement projection 15, can be adopted such as a triangle or a semicircle. Further, the shape may be asymmetric when viewed from the axial direction. The engaging protrusions 15 have the same width over the entire length as shown in FIG. 1 (D) and the same height over the entire length as shown in FIG. 2 (A).

As shown in FIGS. 1 (F) and 1 (G), a ring-shaped annular protrusion (burring-shaped portion) 16 is formed around the screw insertion hole 9 in the metal fitting 6, and the inner peripheral portion thereof is formed by the screw 7. The seating surface 13 of the head 11 is formed as a tapered receiving seat 17, and four of the receiving seats 17 are spaced at equal intervals in the circumferential direction as rotation regulating means on the metal fitting side. The engaging groove 18 of the above is cut open so as to open toward the screw insertion hole 9. Therefore, the portion sandwiched between the adjacent engaging grooves 18 is a tongue-shaped piece 17a having the tip exposed in the screw insertion hole 9 as a free end, and the receiving seat 17 is a four tongue-shaped pieces 17a. It is composed of.

The annular protrusion 16 has a flat top surface 16a and a constricted (or hem-spreading) surrounding wall 16b. Therefore, the cross section is trapezoidal. Of course, the annular projection 16 can have a simple triangular cross-sectional shape without a flat top surface. The engaging groove 18 is formed so as to cross the top surface 16a of the annular protrusion 16. Therefore, each tongue-shaped piece 17a extends to the outside of the head 11 of the screw 7.

As shown in FIG. 2C, the engaging groove 18 is set to a groove width into which the engaging projection 15 is substantially fitted. Therefore, the contact area between the seat surface 13 and the receiving seat 17 can be made as large as possible to ensure high fastening strength. In addition, the effect of preventing the screw 7 from loosening is also excellent. In FIG. 2C, the engaging hole 14 should appear accurately, but the engaging hole 14 is omitted and the whole is shown in cross section.

As can be understood from FIG. 2C, the protruding dimension of the engaging protrusion 15 is set to be smaller than the plate thickness of the metal fitting 6. Therefore, it is certain that the receiving seat 17 functions as a washer, and high fastening strength can be ensured in this respect as well. The protruding dimension of the engaging protrusion 15 may be the same as or smaller than the plate thickness t of the metal fitting 6.

(2). Summary The procedure for attaching the metal fitting 6 is the same as before. Hold the metal fitting 6 in a predetermined position and posture with one hand, and screw the screw 7 into each screw insertion hole 9. When driving the screws 7 between the first and second screws, it is necessary to hold the metal fitting 6 with one hand to hold it in a predetermined position and posture, but when driving the third and fourth screws, hold the metal fitting 6 by hand. You don't have to keep it in.

Then, when the screwing of the screw 7 reaches the final stage, the engaging protrusion 15 hits each tongue-shaped piece 17a, and the engaging protrusion 15 rotates in a state of hitting each tongue-shaped piece 17a, so that the engaging protrusion 15 hits each tongue. The shaped piece 17a is elastically deformed and rotated, and when the engaging protrusion 15 comes off the tongue-shaped piece 17a, each engaging protrusion 15 fits into each engaging groove 18, and the screw 7 can rotate further. As it disappears, each tongue-shaped piece 17a returns and deforms due to the elastic restoring force.

Therefore, the worker can feel a strong resistance by stopping the rotation of the spindle of the power tool, and when the finger is released from the trigger at that time, the rotation of the screw 7 is stopped. Since each tongue-shaped piece 17a is strongly in contact with the waterproof sheet 4 even in the returned deformed state, the screw 7 is screwed into an appropriate predetermined depth, and the metal fitting 6 is received by the seat surface 13 of the screw 7. The seat 17 is strongly pressed.

Each tongue-shaped piece 17a has a spread of a little less than 90 degrees in the circumferential direction, but which part of the tongue-shaped piece 17a in the circumferential direction the engaging projection 15 first hits is not constant. However, it can be said that the engaging protrusion 15 rotates in a state in which the tongue-shaped piece 17a is bent and deformed, although the degree of the engaging protrusion 15 is different, so that the engaging protrusion 15 fits into the engaging groove 18. The waterproof sheet 4 can be strongly pressed by the tongue-shaped piece 17a in the closed state.

Further, since the front side surface 15 b of the engaging protrusion 15 is inclined in the rotation direction, the guide of the front side surface 15 b is provided when the screwing depth is not sufficient even when the engaging projection 15 is fitted in the engaging groove 18. By the action, the engaging projection 15 easily crosses the engaging groove 18 and gets on the adjacent tongue-shaped piece 17a. Therefore, the screw 1 can be rotated until the waterproof sheet 4 is firmly pressed by the tongue-shaped piece 17a.

In the present embodiment, since the engaging protrusions 15 and the engaging grooves 18 are formed four times apart from each other in the circumferential direction, the screw 7 is at least 90 ° after the engaging protrusions 15 first hit the tongue-shaped piece 17a. When the screw 7 is rotated, the engaging protrusion 15 reaches the engaging groove 18, but in the present embodiment, the pitch P of the screw 7 is approximately the same as the valley diameter d. Therefore, when the screw 7 is rotated 90 degrees, the plate of the metal fitting 6 is formed. Only the dimension larger than the thickness t enters. Therefore, in many cases, when the engaging protrusion 15 first hits the tongue-shaped piece 17a and then fits into the next engaging groove 18, the screwing is performed to an appropriate depth.

Therefore, before the screw 7 is screwed into the state where the metal fitting 6 is firmly pressed, the engaging projection 15 does not get stuck in the engaging groove 18 and become inoperable, and high fastening strength can be ensured. Further, since the receiving seat 17 is composed of the tongue-shaped piece 17a divided by the engaging groove 18 and is easily bent and deformed, the engaging projection 15 remains in contact with the receiving seat 17 and is engaged. It is easy to rotate the screw 7 until the joint protrusion 15 fits into the engaging groove 18. In this aspect as well, it is possible to ensure that the screw 7 is driven to a predetermined depth.

As shown in FIG. 2B, the top surface of the head 11 of the screw 7 and the top surface 16a of the annular protrusion 16 are set to form the same surface in a state where the screw 7 is completely screwed. Therefore, the metal fitting 6 can be pressed by the entire seat surface 13 of the screw 1, and the metal fitting 1 can be firmly fixed. It is also possible to set the head 11 of the screw 1 to slightly sink from the top surface 16a of the annular protrusion 16 .

When the engaging groove 18 is formed so as to cross the top surface 16a of the annular protrusion 16 as in the present embodiment, the receiving seat 17 (tongue-shaped piece 17a) is liable to sink and deform. Therefore, for example, the screw 7 If the engaging protrusion 15 suddenly fits into the engaging groove 18 or hits the receiving seat 17 slightly in front of the engaging groove 18 when screwing in, the receiving seat 17 is deformed and the engaging protrusion 15 is formed. It becomes easy to move over the engaging groove 18 to the adjacent tongue-shaped piece 17a. Therefore, there is an advantage that the rotation of the screw 7 is stopped in a state where the screw 7 is firmly screwed into a predetermined depth.

In the case of the present embodiment, since the waterproof sheet 4 on which the metal fittings overlap is soft, the receiving seat 17 made of the tongue-shaped piece 17a is easily bent and deformed by being pushed by the engaging projection 15 of the screw 7. Therefore, it is more certain that the screw 7 is driven to a predetermined depth. Therefore, it can be said that the present invention is particularly suitable when the metal fitting 7 overlaps the soft member.

However, when the annular protrusion 16 is formed and the receiving seat 17 is formed on the annular protrusion 16 as in the embodiment, there is a vacant space on the back side of the receiving seat 17, so even if the metal fitting 6 overlaps the inflexible member. , The receiving seat 17 can be elastically deformed by being pushed by the engaging projection 15. Therefore, even when the metal fitting 6 does not overlap with a flexible member that is easily compressed and deformed, it is possible to deform the receiving seat 17 and drive the screw 7 to a predetermined depth.

It is also possible that the engagement groove 18 does not completely cross the top surface 16a of the annular projection 16 but has its end positioned in the middle of the top surface 16a. Alternatively, or formed across the entire circumference Ikabe 16b, it is possible or to reach up to the middle of the surrounding wall 16b.

The screw 7 is manufactured from a wire rod, the head 11 is rolled by a header, and the screw thread 12 is rolled by a die. The engaging protrusion 15 is formed at the same time as the head 11 is pressed. Therefore, processing is easy. Further, the engaging groove 18 can be easily formed at the same time as or after the processing of the annular protrusion 16.

(3). Second embodiment (Fig. 3)
FIG. 3 shows a second embodiment. In this embodiment, the screw 7 is the same as in the first embodiment. Further, the metal fitting 6 is basically the same as that of the first embodiment, and the annular projection 16 is formed with four engaging grooves 18, and the receiving seat 17 is composed of four tongue-shaped pieces 17a.

The difference between this second embodiment and the first embodiment is that the annular protrusion 16 is higher in height than that of the first embodiment, and each tongue-shaped piece 17a has a screw 7. It is a point that is gradually inclined so as to widen the distance from the surrounding wall 16b in the direction of rotation, and therefore, a step is formed between the adjacent tongue-shaped pieces 17a.

As an explanation of the form of each tongue-shaped piece 17a, it can be said that the screw 7 is twisted and deformed so that the distance from the reference conical surface gradually increases in the rotation direction. The step between the adjacent tongue-shaped pieces 17a is the largest at the tip (free end) of each tongue-shaped piece 17a, and is zero at the upper end. The maximum step size is indicated by E.

In this embodiment, the maximum step dimension E is, P is the pitch of the threads 12 in the screw 7, the number of tongues 17a (N) is a 4, setting these relationships, the E> P / 4 (E = P / 4 may be used). Further, assuming that the lead angle of the screw thread 12 is θ2 and the angle formed by the upper ends of the tip edges of the adjacent tongue-shaped pieces 17a facing each other is θ3, the relationship of θ3> θ2 is set. Further, when the width of each tongue-shaped piece 17a in the circumferential direction is displayed by an angle, it becomes θ4 (<90 degrees).

One of the features of the present embodiment is that each tongue-shaped piece 17a is twisted and deformed. However, when configured in this way, the engaging protrusion 15 is engaged as shown in FIGS. 3 (B2) and 3 (B3). Since the seat surface 13 of the screw 7 is in contact with each tongue-shaped piece 17a in a state of being fitted into the joint groove 18 in a deformed state, the waterproof sheet 4 is firmly attached by the metal fitting 6. It can be pressed to secure the desired fastening strength.

Therefore, even if there is a partial gap between the tongue-shaped piece 17a and the seat surface, the tongue-shaped piece 17a is deformed in the direction of untwisting and becoming a reference conical surface. The waterproof sheet 4 can be firmly pressed with. That is, the waterproof sheet 4 can be firmly pressed and fixed by utilizing the elastic restoring force of the tongue-shaped piece 17a.

By the way, the engaging protrusion 15 hits the tongue-shaped piece 17a by screwing the screw 7, but which part in the circumferential direction first hits is not constant, and as shown in the left end and the right end of FIG. 3 (B1). In the tongue-shaped piece 17a, it may hit the rear start end portion in the rotation direction (screw-in direction) of the screw 7, or it may hit the front end portion in the rotation direction of the screw 7. Then, for example, when the engaging protrusion 15 first hits a region of about half of the starting end side of the tongue-shaped piece 17a, the amount of deformation of the tongue-shaped piece 17a is large, so that the engaging protrusion 15 is the engaging groove 18. Even if the tongue-shaped piece 17a is returned and deformed by being fitted into the tongue-shaped piece 17a, the pressing force of each tongue-shaped piece 17a by the seat surface 13 of the screw 7 is maintained in a high state, and therefore a high fastening strength can be maintained.

On the other hand, if the engaging protrusion 15 first hits the terminal portion of the tongue-shaped piece 17a and then immediately fits into the engaging groove 18, the pressing force of the tongue-shaped piece 17a by the seat surface may be insufficient. Conceivable. However, in the present embodiment, since θ3> θ2, as can be understood from the line shown on the right side of FIG. 3 (B1), when the engaging protrusion 15 comes into contact with the end portion of one tongue-shaped piece 17a. Straddles the engagement groove 18 and rides on the next tongue-shaped piece 17a. As a result, the tongue-shaped piece 17a can be firmly pressed by the seat surface 13 to secure a desired fastening strength.

From the state shown in the right side portion of FIG. 3 (B1), the engaging projection 15 must be engaged at a position considerably close to the end of the tongue-shaped piece 17a (position where θ5 is close to θ4) and not first contacted. I get the impression that the protrusion 15 cannot straddle the engagement groove 18, but in reality, as shown in FIG. 1 (E), the front side surface 15 b of the engagement protrusion 15 is inclined, so that the protrusion 15 is engaged. Even if the joint protrusion 15 fits into the engaging groove 18, if the fitting condition is shallow, a phenomenon occurs in which the engaging protrusion 15 separates from the engaging groove 18 and rides on the adjacent tongue-shaped piece 17a. Therefore, in reality, θ5 is considerably smaller than θ4. Two sides 15a of the engagement projection 15, of 15b, it is also possible to set the angle θ1 of at least the front side surface 15 b, for example, a large angle of about 40-60 degrees.

Further, even if the engaging projection 15 enters the engaging groove 18, if the entry is shallow, a phenomenon occurs in which the adjacent tongue-shaped piece 17a is pushed down by the engaging projection 15 due to the inertia of rotation, so that the adjacent tongue It becomes easier to get on the shape piece 17a. Due to these synergistic actions, the screw 7 can be screwed firmly. The protrusion size of the engagement protrusion 15 is preferably as small as possible within a range in which the function of fitting into the engagement groove 18 when a predetermined rotational resistance is generated in the screw 7 can be ensured.

In the reference example of FIG. 4 , a state in which a plurality of metal fittings 6 are fastened with one screw 7 is shown. Since the waterproof sheet 4 thermally expands and contracts, expansion and contraction are repeated due to the temperature difference between day and night and the temperature difference throughout the year. Then, it is considered that the screw 7 is screwed back through the metal fitting 6 due to the waterproof sheet 4 extending or contracting in the direction connecting the two metal fittings 6. Then, as shown by the alternate long and short dash line in FIG. 4B, it cannot be said that the screw 7 does not loosen.

In this regard, when each tongue-shaped piece 17a is twisted and deformed as in the present embodiment, the waterproof sheet 4 is pressed by the screw 7 via the metal fitting 6 due to the elastic restoring force of the tongue-shaped piece 17a. It is possible to prevent the metal fitting 6 from shifting and accurately prevent the screw 7 from loosening. Deformation of the tongue-shaped piece 17a by screw has an advantage in this respect as well.

In the reference example of FIG. 4, the metal fitting 6 is not provided with an annular protrusion and is a flat type. Since the head 11 of the screw 7 is dish-shaped, the metal fitting 6 is formed with a tapered screw insertion hole. The engagement groove 18 is formed so as to extend radially toward the outside of the head 11 of the screw 7. When the metal fitting 6 overlaps the flexible member, the receiving seat can be easily deformed, so that the practicality is high even if the annular protrusion 16 is not provided.

(4). Others The invention of the present application can be embodied in various ways other than the above-described embodiments. For example, the shape and dimensions of the metal fittings can be arbitrarily set according to the application. In the case of metal fittings that only function as holding plates, stud bolts are naturally unnecessary. In the case of a metal fitting for attaching another member, it is also possible to form a tap hole and screw a screw or a bolt into the tap hole to fix the other member.

Even in the reference example in which the metal fitting does not have an annular protrusion as shown in FIG. 4B, the height of each tongue-shaped piece increases in the screwing direction of the screw as in the second embodiment. When set to the twisted and deformed form, there is an advantage that high fastening strength can be secured by utilizing the elastic restoring force of the tongue-shaped piece. Further, although it is not necessary to mention it, twisting and deforming the tongue-shaped piece can also be applied to the first embodiment. When twisting and deforming a tongue-shaped piece, it is preferable to twist the whole tongue from the viewpoint of ease of processing, but if conditions permit, for example, only a part on the tip side is deformed and adjacent to each other. It is possible to form the tongue-shaped piece so that a step is generated only on the tip side.

When Kakarigo突to cause the fine elongated, there is an advantage that fits fit is ensured between the engagement groove and the engagement hole. The number of engaging protrusions, engaging grooves, and engaging holes can be set arbitrarily. It is also possible to make the numbers of both different. That is, it is possible to set the number of engaging grooves to an integral multiple of the engaging projections.

The invention of the present application can be actually embodied in a fastening device. Therefore, it can be used industrially.

1 Girder material that composes the roof 2 Roof plate (ALC plate) as an example of the base material
3 Insulation material 4 Tarpaulin 5 Fastening device 6 Metal fittings 7 Screws 8 Stud bolts 9 Screw insertion holes 10 Axis 11 Heads 12 Threads 13 Seat surface 15 Engagement protrusions
15a Rear side facing the screw back direction
15b Front side surface 16 facing the screwing direction 16 annular protrusion (bank)
17 Receiving seat 17a Tongue-shaped piece 18 Engagement groove θ2 Thread lead angle θ3 Maximum inclination angle of the step between adjacent tongue-shaped pieces

Claims (4)

It consists of a metal fitting that overlaps the base material and a screw that fixes the metal fitting to the base material.
The screw is a countersunk screw having a tapered head seat surface, and a plurality of engaging protrusions extending in the radial direction when viewed from the axial direction are formed on the head seat surface apart from each other in the circumferential direction. On the other hand
The metal fitting is formed with a screw insertion hole through which the shaft of the screw passes and an annular protrusion having a tapered receiving seat on which the seating surface of the head of the screw overlaps, and the tip of the metal fitting is formed on the receiving seat of the annular protrusion. A plurality of engaging grooves extending in the radial direction are formed apart in the circumferential direction while opening in the screw insertion hole.
The portion sandwiched between the adjacent engaging grooves becomes a tongue-shaped piece having the tip facing the screw insertion hole as a free end, and the tongue- shaped piece is deformed so that the engaging projection fits into the engaging groove. It is a configuration that regulates the rotation of the screw by turning
The engaging protrusion has a double-sided tapered shape in which both the side surface facing the screwing direction and the side surface facing the screwing back direction are inclined so as to narrow in the radial direction when viewed from the axial direction. While set to the same width and height over the entire length
The tongue-shaped piece extends to the outside of the head of the screw by extending the base end of the engaging groove beyond the receiving seat to at least the top surface of the annular projection.
Fastening device. At least the free end of each tongue-shaped piece is inclined so that the back is low and the front is high toward the screwing rotation direction of the screw, so that a step is formed between the adjacent tongue-shaped pieces. Has been
The fastening device according to claim 1. When the number of the tongue-shaped pieces is N, the pitch of the screws is P, and the maximum dimension of the step between the adjacent tongue-shaped pieces is E, the relationship of E> (P / N) is established. On the other hand
The protrusion dimension of the engaging protrusion from the seat surface is smaller than or equal to the thickness dimension of the tongue-shaped piece.
The fastening device according to claim 2. A stud bolt for fixing the solar panel is projected from the metal fitting, the receiving seat is formed around the stud bolt, and the frame material forming the outer peripheral portion of the solar panel is attached to the stud bolt. It is set to be fitted and fixed with nuts,
The fastening device according to any one of claims 1 to 3.

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