JP4568647B2 - Fastener - Google Patents

Description

The present invention is suitable fastening again and again relates to fix the soft material such as a covered heat insulating material in a waterproof sheet in a hard material such as a steel member.

In some cases, the roof of a building is composed of a folded plate or deck plate having a concavo-convex cross section, and in this case, a heat insulating material covered with a waterproof sheet is stretched on the roof. Although the waterproof sheet and the heat insulating material are fixed with screws (screws), for example, a disk-shaped washer having a large area of about 80 mm in diameter is used (see Patent Documents 1 and 2). The washer includes a metal plate and a resin. Further, as the screw, a drill screw or a tapping screw is often used.
Japanese Patent No. 3416644 JP 2000-170737 A

  By the way, the building may vibrate minutely due to walking of people, driving of an air conditioner, and the like, and the screw fixing the waterproof sheet and the heat insulating material may be loosened due to such vibration. In buildings where there are many devices and equipment that become sources of vibration, such as factories, loose screws are likely to appear.

  In addition, when the screw head hits a hard work, for example when fastening steel plates, the screw head cannot be screwed any further when the screw head hits the work. When fixing a soft material such as this, the washer will dig into the waterproof sheet and the heat insulating material, so it will be necessary to rely on the operator's intuition to determine how much it will be screwed in. There was also concern that it would be easy to loosen.

  In addition, since the hole of the washer is set to be slightly larger than the outer diameter of the screw, the screw often comes out of the washer during storage, and it is necessary to fit the screw into the washer before work. there were. Also, in the case of drill screws, the outer diameter of the drill part is often set to be slightly larger than the root diameter of the thread, so sufficient fastening strength is ensured when the plate thickness of the member to be screwed becomes thinner to some extent. In some cases, it was not possible.

  This invention makes it a subject to improve such a present condition.

The present invention is a fastener relating to a combination of a screw and a washer. This fastener has a tip portion provided with a head at the proximal end of the shaft thread is formed on the outer circumference and threads formed on the drill part, and the sheet metal washer which shaft has a circular hole fitting of the screw and consist, the washer is provided with a seat receiving portion seat surface overlap of the head of the screw and the extension portion extending outside, much larger than the area of the area the seat receiving portion of the extension portion It has become. Then, the seat receiving portion of the seat and washer head before Symbol screws, thereby screwing rotating the screw in a state of fixing the washer to be allowed back screws are formed engaging means for preventing.

Further in the present invention, the bearing surface of the head in the screw is tapered to reduce the outer diameter toward the shaft, the bearing surface of this, as the engaging means on the side of the screw, extending radially A plurality of protrusions are formed at equal intervals along the circumferential direction, and the protrusions gradually increase in height in the direction of unscrewing in a plan view and approach the outer periphery of the head. Accordingly , the washer is inclined so as to have a maximum height in the longitudinal sectional view, while the washer receiving portion of the washer has the same number of tongues as the protrusions by slits or slits extending radially at equal intervals in the circumferential direction. are divided into pieces, the respective tongue, unscrewing the front side of the portion toward the direction of rotation of the screw has torsionally formed so displaced radially inwardly, wherein the side of each tongue washer Engaging means.

A second aspect of the present invention, in claim 1, the distal end portion of the shaft of the screw is formed in the drill part, it said axis, said first screw thread contiguous to the drill part, near the under head position to forms a second thread having a larger outer diameter than the first thread, while it is set to a diameter smaller than the root diameter of the first thread of the outer diameter of the drill portion, The inner diameter of the hole of the washer is set to be larger than the outer diameter of the first thread and smaller than the outer diameter of the second thread.

  Since the outer diameter of the washer of the present invention is much larger than the head of the screw, when it is in close contact with the work and pressed by the head of the screw, a strong frictional resistance is imparted against the rotation of the washer. And since the engaging means exists in the screw thread and the washer, the screw must be rotated together to unscrew the screw, but there is a large frictional resistance between the washer and the workpiece, The screw and washer are prevented from rotating in the loosening direction.

  Therefore, in fixing a soft material to a hard material such as fixing a heat insulating material with a waterproof sheet to a support member such as a folded plate or a deck plate, fixing a heat insulating material for a wall to a steel pillar, The loosening of the screw can be prevented or significantly suppressed.

And further described, it is possible to improve the effect stopped loosening and more accurately maintain the state engagement of the tongue piece of the collision caused the washer of the root Ji of the seat surface.

In other words, assuming that the depth of engagement between the projection or groove formed on the seat surface of the screw head and the tongue of the washer is 1 mm, if the screw head is a pan head or a hexagon head, the screw is for some reason. When rotating in the loosening direction and moving 1 mm in the axial direction, the engagement between the protrusion or groove and the tongue piece is released, and the loosening of the screw proceeds.In the present invention, if the inclination angle of the seating surface with respect to the axial center is θ, In order to release the engagement between the protrusion or groove and the tongue piece, the screw must move in the axial direction by (1 / sin θ) mm. Therefore, even if the screw is loosened, the screw engages with the washer. The state is maintained for as long as possible, and as a result, a high locking effect can be secured.

Further, in the present invention, while the collision force of the bearing surface of the screw head can be simultaneously formed upon processing a head with header tongue of the seat receiving portion of the washer can be formed simultaneously when manufacturing the washer by pressing, this Therefore, there is an advantage that the cost can be suppressed.

According to the second aspect of the present invention, the second screw thread is screwed into the hole of the washer so that the washer can be kept attached to the lower neck portion of the screw. The work efficiency can be improved by eliminating the trouble of fitting in. In addition, when the outer diameter of the drill portion is set smaller than the first thread valley diameter as in claim 2 , the screw valley portion is firmly attached to a member such as a folded plate, thereby ensuring high fastening strength. can do.

  Next, an embodiment of the present invention will be described with reference to the drawings.

The fastener of this embodiment is composed of a drill screw 1 as a kind of screw and a metal plate washer (disk) 2, and in FIG. 1A, the front shape of the drill screw 1 and the washer 2. The cross-sectional shape is displayed. First, the structure of the drill screw 1 will be described with reference to FIGS.

(1). Drill Screw Structure FIG. 1B is a plan view, FIG. 1C is a sectional view taken along the line CC of FIG. 1A, and FIG. E) is a sectional view taken along line EE of (C), (F) is a sectional view taken along line FF of (A), and (G) is a partial plan view of the washer 2.

  The drill screw 1 includes a shaft 3 and a head 4 provided at the base end thereof, and a drill portion 5 is integrally formed at the tip of the shaft 3. The drill part 5 is a general aspect, and has two cutting edges 5a and longitudinal grooves 5b. Needless to say, the form of the drill portion 5 can be freely set as required.

  The shaft 3 is formed with one long first screw thread 6 connected to the drill portion 5 and one short second screw thread 7 close to the head 4 side. Between these, there is a screwless portion 8. The first thread 6 controls fastening, and the pitch P1 and the outer diameter D1 are set to dimensions that secure the function of screwing into the member, while the second thread 7 functions to attach the washer 2. Thus, the pitch P2 and the outer diameter D2 of the second thread 7 are set to be larger than those of the first thread 6. The dimensional difference between D1 and D2 may be about 1 to 2 mm.

  An example of the cross-sectional shape of the first thread 6 is shown in FIG. 2A, and an example of the cross-sectional shape of the second thread 7 is shown in FIG. The white arrows in both figures indicate the screwing direction, and the first thread 6 has an inclination angle (angle formed with respect to a line perpendicular to the axis) θ1 of about 35 degrees on the leading side flanks 6a, and the trailing side The inclination angle of the flange 6a is set to about 10 degrees, and the entire mountain angle θ2 is about 45 degrees.

  On the other hand, the inclination angle of the second thread 7 is substantially the same for both the advancing flank 7a and the follower flank 7b, and the overall crest angle θ3 is set to about 30 degrees. Therefore, even if the heights of the two screw threads 6 and 7 are different, the cross-sectional area does not change so much, and therefore the valley diameter is almost the same. For this reason, it can prevent that intensity | strength falls by a valley diameter becoming small in the location of the 2nd thread 7. That is, in the second thread 7, the outer diameter (in other words, the height of the mountain) D <b> 2 is increased without causing a decrease in strength.

  The reason why the inclination angle of the follower flank 6b is reduced in the first thread 6 is to increase the frictional resistance with the member to be screwed, and the angle θ2 of the thread is larger than that of the second thread 7. This is to secure strength and prevent crushing.

  As shown in FIG. 1 (F), in this embodiment, the outer diameter of the drill portion 5 (exactly the diameter of the circumscribed circle of the drill portion 5) D3 is slightly smaller than the valley diameter D4 of the first thread 6. It is set. The dimensional difference between D3 and D4 differs depending on the thickness of the screw. However, if the nominal diameter (D1) is about 6 mm, it may be about 0.2 mm to 0.3 mm. Note that both outer diameters D3 and D4 may be set to the same diameter.

The head 4 is a countersunk head having a seating surface that is tapered toward the shaft 3, and a rectangular engagement hole 4 a is vacant on the top surface (other engagement holes such as a cross hole). may be formed.). Then, four protrusions 9 are formed at equal intervals along the circumferential direction as an example of the engaging means on the tapered seat surface. Each protrusion 9 extends in the radial direction from the base portion of the shaft 3 and increases in height toward the outer periphery of the head 4.

The protrusion 9 gradually increases in height in the screw unwinding direction (the direction indicated by the white arrow in FIG. 1D) , and also follows the trailing end surface 9a positioned at the terminal end in the screwing rotation direction. Is formed so as to extend in the radial direction in plan sectional view. In other words, the protrusion 9 has a shape resembling a saw blade that decreases in distance from the axial center as it moves away from the trailing end surface 9a in the circumferential direction. Therefore, the height (in other words, the level difference) H of the protrusion 9 is the maximum height H0 at the location of the trailing end surface 9a and at the location of the outer peripheral edge.

  Assuming that the seating surface has a complete trapezoidal shape as a reference state, a part of the protrusion 9 is raised radially outward from the reference state, and a part thereof is recessed radially inward from the reference state. Strictly speaking, the projection and the groove are formed in a concavo-convex shape, but in the present embodiment, the projection is simply shown as the projection 9. The outer peripheral surface of each projection 9 has a loose arc shape in a plan view, but can also be a straight line in a plan view.

  The maximum height dimension H0 of each protrusion 9 is set to a dimension larger than 1/4 of the pitch P1 of the first thread 4. More generally, the maximum height dimension H0 of each projection 9 is set to a dimension (for example, twice or more) larger than the dimension obtained by dividing the pitch P1 of the first thread 6 by the number of projections 9. . The reason why the dimensions are set will be described later.

(2). Structure of Washer The washer 2 is composed of a seat receiving portion 10 where the seating surface of the head 4 of the drill screw 1 overlaps, and an extension portion 11 extending outside thereof, and the outer diameter of the extension portion 11 is a drill screw. The size is much larger than the outer diameter of one head 4 (for example, 5 to 10 times).

  As a matter of course, the washer 2 has a hole 12 in which the shaft 3 is fitted, and the inner periphery thereof is a seat receiving portion 10, and the seat receiving portion 10 is a seating surface of the head 4 of the drill screw 1. It is formed in a taper shape so as to overlap. Further, the extended portion 11 is formed with a flange 11a constituting the outer peripheral edge, and an annular recessed portion 11b that overlaps the workpiece between the flange 11a and the seat receiving portion 10.

  Needless to say, the cross-sectional shape of the washer 2 can be arbitrarily set. For example, a shape in which the recessed portion 11b does not exist, a shape in which a plurality of recessed portions are formed in a wavy shape, or a shape in which a flange having a large area spreads from just outside the seat receiving portion 10 is used. . The washer 2 is not necessarily formed in a circular shape, and can be formed in a square shape such as a hexagon or an octagon.

Of (A) is an enlarged plan view of the seat receiving portion 10 of FIG. 3, a IIIC-IIIC sectional view of (B) is B-B view of (A), (C) Fig. 1 (A). As shown in these drawings, the seat receiving portion 10, that is separated by the four points which equally spaced in the circumferential direction four cuts radially extending (slit) 13 in four tongues 14.

And each tongue piece 14 is set so that the distance from the center of the hole 12 becomes far as it goes ahead from the front part toward the screw unwinding rotation direction of the drill screw 1 (the black arrow direction in FIG. 3C). As a result, each tongue piece 14 has a step (or height difference in the radial direction) of the dimension H1 between the front end and the rear end viewed along the circumferential direction. Step H1 is you are set to larger than the 1/4 of the pitch P1 of the first thread 6 in the drill screw 1 (e.g. 2-3 times).

  The drill screw 1 is rotated in the direction of the white arrow in FIG. 3C by screwing. For convenience, the tip surface of the tongue piece 14 facing the screwing rotation direction of the drill screw 1 is referred to as a leading side end surface. 14a is attached. Then, as shown in FIG. 4C, each tongue piece 14 overlaps with the projection 9 on the seating surface of the head 3 in the drill screw 1, and the advancing side end surface 13 a of the tongue piece 14 contacts the follower side end surface 9 a of the projection 9. It is set so that it can contact.

  The inner diameter of the hole 12 in the washer 2 (more precisely, the diameter of the inscribed circle in contact with the tip edge of each tongue piece 14) D5 is slightly smaller than the outer diameter D1 of the first thread 6 (for example, 0.1 to 0). .. about 3 mm) and a smaller diameter than the outer diameter D2 of the second thread 7.

(3). Description of Use State Next, the use state will be described with reference to FIG. In this example, the heat insulating material 17 covered with the waterproof sheet 16 is used for fixing to a support member 18 made of a metal plate such as a folded plate or a deck plate. Needless to say, the waterproof sheet 16 is resin-based or asphalt-based and has flexibility. The heat insulating material 17 includes various materials such as rock wool and glass wool. In any case, the material is somewhat elastically deformed when a compressive force is applied.

  The method of using the fastener of the present embodiment is the same as in the prior art. The drill screw 1 is fitted into the washer 2 and pressed while rotating the drill screw 1 by a power driver, and the waterproof sheet 16, the heat insulating material 17, and the support member 18 are used. Then, the first thread 6 is screwed into the support member 18 until the washer 2 slightly dents the waterproof sheet 16. Thereby, the waterproof sheet 16 and the heat insulating material 17 are pressed and fixed by the head 4 of the drill screw 1 through the washer 2.

  In this embodiment, the washer 2 is attached to the lower part of the neck of the drill screw 1 in the initial state of the fixing operation, and the washer 2 overlaps the upper surface of the waterproof sheet 16 by driving the drill screw 1, and then the washer 2 is the drill screw. The heat insulating material 17 is slightly compressed while the waterproof sheet 16 is recessed due to the pressing action of the head 4.

  After the screw screw 1 has been screwed in, the seat surface of the head 4 of the drill screw 1 is in strong contact with the seat receiving portion 10 of the washer 2. However, the tongue piece 14 is in close contact with the projection 9 and is shown in FIG. Thus, there can be a case where the advancing side end surface 14 a of the tongue piece 14 is in contact with the follower side end surface 9 a of the projection 9 and a case where the advancing side end surface 14 a of the tongue piece 14 is separated from the follower side end surface 9 a of the projection 9. .

  When the drill screw 1 is loosened for some reason, if the leading end surface 14a of the tongue piece 14 is in contact with the follower side end surface 9a of the projection 9, the drill screw 1 and the washer 2 together. Otherwise, it cannot rotate in the loosening direction, but the washer 2 has a large diameter and is in close contact with the waterproof sheet 16 over a wide range, so that a large frictional resistance exists between the washer 2 and the waterproof sheet 16. Therefore, loosening of the drill screw 1 is prevented or significantly suppressed.

  When the advancing side end surface 14a of the tongue piece 14 in the washer 2 is separated from the follower side end surface 9a of the projection 9 with the drill screw 1 screwed, the advancing side end surface 14a of the tongue piece 14 is projected. 9 can rotate back until it abuts on the trailing end surface 9a. In this case, since the leading side end surface 14a of the tongue piece 14 is located somewhere between the adjacent trailing side end surfaces 9a of the head 4 of the drill screw 1, the maximum range in which the drill screw 1 can return and rotate is The rotation angle is 90 degrees, and the axial distance is 1/4 of the pitch P1 of the first thread 6.

  The maximum height H0 of the protrusion 9 and the step H1 of the tongue piece 14 are larger than 1/4 of the pitch P1 of the first screw thread 6, and the washer 2 is provided with the waterproof sheet 16 and the heat insulating material. 17 is elastically deformed, and the tongue piece 14 is elastically deformed by the pressing action of the head 4 of the drill screw 1, so that the washer 2 remains waterproof even if the drill screw 1 returns and rotates. The advancing side end surface 14a of the tongue piece 14 abuts on the follower side end surface 9a of the projection 9 while being in a state of being in close contact with the screw 16, so that the return rotation (ie, loosening) of the drill screw 1 is caused by the washer 2 and the waterproof sheet 16 It is blocked by the friction between them.

  Further, as shown in FIG. 4D, when the inclination angle formed by the seat surface of the head 4 in the drill screw 1 with respect to the axis O is θ4, the drill screw 1 is rotated back and the tongue piece 14 is projected 9. The distance H2 is necessary to detach from H, but H2 has a dimension of (H0 × 1 / sin θ4) and is much larger than H0. Therefore, H0 is made as small as possible to ensure the ease of processing. It can exhibit a locking effect. This is an advantage of the present embodiment.

  Further, since the outer diameter D2 of the second thread 7 is larger than the inner diameter D5 of the hole 12 of the washer 2, the washer 2 can be kept held under the neck of the drill screw 1 during storage and transportation. For this reason, the trouble at the time of work can be reduced. Note that the pitch P2 of the second screw thread 7 is larger than the plate thickness of the washer 2. Therefore, there is no problem in mounting the washer 2.

  Although it is possible to make the inner diameter D5 of the hole 12 of the washer 2 smaller than the outer diameter D1 of the first thread 6 (in this case, the second thread 7 is unnecessary), in this case, the drill screw 1 is attached to the washer. Since it has to be screwed into 2, it takes time to install. On the other hand, if the second screw thread 7 shorter than the first screw thread 6 is formed near the neck of the drill screw 1 and formed as a stopper for the washer 2 as in the present embodiment, the mounting is easy. There is an advantage that the washer 2 can be held in a state in which it is not dropped while securing.

  Since the outer diameter D3 of the drill portion 5 is smaller than the valley diameter D4 of the first thread 6, the location of the first thread 6 has bitten into the support member 18, thereby securing the fastening strength.

  By the way, in the drill screw, generally, the roots of adjacent peaks are in close contact with each other, and the vertical cross-sectional shape of the valley is a triangle. The same point as the thickness of the root of the thread is spaced between the roots of the combined threads, and the valley has a trapezoidal cross section. For this reason, the first screw compared to a general drill screw. The lead angle of mountain 6 is large. Since the lead angle is large in this way, the first thread 6 can be quickly passed through the waterproof sheet 16, the heat insulating material 17, and the support member 18 to improve the work efficiency.

  As described above, since the outer diameter D4 of the drill portion 5 is smaller than the outer diameter D5 of the first thread 6, the portion of the first thread 6 is engaged with the support member 18 and fastened. Therefore, the present embodiment has an advantage that the work efficiency can be improved without causing a decrease in fastening strength.

(4). Others

  The present invention can be embodied in various ways other than the above embodiment.

For example, provided the portion for increasing the frictional resistance between the workpiece washers, Ri also der or to form a nail biting into the workpiece, the washers adding various functions depending on the work and the kind and the intended use it is Ru can be.

Is a diagram showing the structure of implementation forms. It is an expanded sectional view of a screw thread. It is a figure which shows the principal part of a washer. It is explanatory drawing of a use state.

DESCRIPTION OF SYMBOLS 1 Drill screw as an example of screw 2 Washer 3 Axis 4 Head 5 Drill part 6 1st screw thread 7 2nd screw thread 9 Projection which comprises the engaging means of a screw 10 Washer seat receiving part 12 Washer hole 13 Notch ( slit)
14 Tongue

Claims (2)

A screw having a head at the proximal end of the shaft threads are formed on the outer periphery, and consists of a metal plate washer with full bore axis fitting of the screw,
The washer is provided with a seat receiving portion seat surface overlap of the head of the screw and the extension portion extending outside, it has become much larger than the area of the extension of the area of the seat receiving portion, further , to a seat receiving portion of the seat and washer head in the screw, thereby screwing rotating the screw in a state of fixing the washer to be allowed back screws are formed engaging means for preventing,
The structure
The head seat surface of the screw is formed in a taper shape whose outer diameter decreases toward the shaft, and a plurality of protrusions extending in the radial direction are provided on the seat surface as engagement means on the screw side. The protrusions are formed at equal intervals along the circumferential direction, and the protrusions gradually increase in height toward the screw unwinding direction in a plan view, and the maximum height increases toward the outer periphery of the head. While it is also inclined in vertical section view ,
The washer receiving portion of the washer is divided into the same number of tongue pieces as the protrusions by slits or slits extending radially at equal intervals in the circumferential direction. The front side portion is twisted so as to shift radially inward, and each of the tongue pieces forms the engaging means on the washer side,
Fasteners. A tip portion of the shaft of the screw is formed in a drill portion, and the shaft has the first screw thread continuous with the drill portion and an outer diameter located near the neck and smaller than the first screw thread. Is formed with a large second thread, and the outer diameter of the drill portion is set smaller than the root diameter of the first thread,
The inner diameter of the hole of the washer is set to be larger than the outer diameter of the first thread and smaller than the outer diameter of the second thread;
The fastener according to claim 1.

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