JPH11311226A - Combination of screw and driver bit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combination of a screw and a driver bit effectively preventing the come-out phenomenon of the driver bit, preventing the damage of the screw and always attaining appropriate and rapid thread-fastening work even in the case of a cross groove part of the screw being damaged, thereby improving work efficiency. SOLUTION: A screw head is provided with a bit fit-in groove 32 formed of a cross groove. The edge parts of this bit fit-in groove 32 are formed as nearly vertical end wall parts 32a of specified depth, and plane bottom parts 32b are formed pointing to the center part of the screw head from the lower edge parts of the vertical end wall parts 32a. Inclined groove parts 32c are further formed pointing to the center part of a screw neck part from the plane bottom parts 32b, and a nearly conical bottom face 34 is formed at the intersecting center part to constitute a screw 30. In this case, the bit fit-in groove 32 is formed as grooves 33a, 33b spreading out in groove width, pointing radially outward from the center part of the screw head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw and a driver bit applied to the screw, and more particularly, to a method for tightly fitting a cross groove formed in the head of a screw with a driver bit adapted to the groove. The present invention relates to a combination of a screw and a screwdriver bit that can quickly and reliably achieve the mounting and dismounting of a screw by always transmitting an appropriate torque.

[0002]

2. Description of the Related Art As a conventional combination of a screw and a driver bit, a combination as shown in FIGS. 7 to 10 is known. 7 and 8
10 shows a screw having a conventional cross groove, FIG. 9 shows a driver bit for the cross groove screw, and FIG.
Indicates a fitting state between the screw and the driver bit.

However, the conventional screw 10 shown in FIG.
A cross groove 12 is provided in the screw head 10a. Each of the cross grooves 12 has an inclined groove 12a extending from the edge to the center of the screw neck 10b, and a gently inclined substantially conical bottom surface 14 is formed at the bottom. It consists of a configuration. Reference numeral 13
Indicates tapered side wall portions formed between adjacent cross grooves 12, respectively. That is, the tapered side wall portion 13 abuts and engages with a blade portion of a driver bit described later. Further, in the corner portion adjacent to each of the inclined groove portions 12a, the cross groove 1 of the screw head 10a is positioned from the position of the conical bottom surface 14.
Tapered coupling surfaces 17a, 17b extending to the edge of the second opening
Are formed respectively, and these tapered coupling surfaces 17a, 17
As for b, it is configured to abut and engage with a part of the blade portion of the driver bit described later.

On the other hand, a conventional driver bit 20 shown in FIG. 9 has a blade portion 22 fitted in the cross groove 12 of the screw 10.
And extended blade portions 22a each extending to match the shape of the inclined groove portion 12a formed so as to extend from the edge of the cross groove 12 toward the center of the screw neck 10b. It consists of a formed configuration. Reference numeral 23 denotes tapered side wall portions formed on both side surfaces of each blade portion 22 or the extended blade portion 22a. That is, the tapered side wall portion 23 abuts and engages with the tapered side wall portion 13 formed in the cross groove 12 of the screw 10 described above.

According to the conventional combination of a screw and a driver bit configured as described above, as shown in FIG.
When the screw 10 and the driver bit 20 are fitted together, as described above, the respective blade portions 22 and the extended blade portions 22a of the driver bit 20 are respectively fitted to the inclined groove portions 12 of the cross groove 12.
a, and the side wall 23 of each of the blade portions 22 and the extension blade portion 22a is formed into a tapered side wall portion 13 of the cross groove 12 of the screw 10.
The predetermined torque can be transmitted to the screw 10 by rotating the driver bit 20 in contact with the screw. That is, it is possible to mount or remove a screw on a required screw mounting object.

[0006]

However, the conventional screw 10 and driver bit 20 having the above-described structure are used.
According to the combination with the screw head 1 as shown in FIG.
The cross groove 12a has a fixed inclined groove portion 12a which is directed from the edge to the center of the screw neck portion 10b, while the corresponding driver bit 20 is provided with the extended blade portion 22a. The ridge portion is fitted into the cross groove 12 in conformity with the shape of the inclined groove portion 12a, and the ridge portion of the extended blade portion 22a is formed to be gradually wider toward the rear from the tip. Further, the tapered side wall portion 23 formed on each blade portion 22 of the driver bit 20 also comes into contact with and engages with the tapered side wall portion 13 formed on the cross groove 12 of the screw 10. When the driver bit 20 is turned in the direction, the contact state between the driver bit 20 and the cross groove 12 can be said to be a taper contact on the entire surface. (See the arrow in FIG. 10), the so-called come-out phenomenon occurs.

In particular, the shape of the cross groove of the conventional screw is shown in FIG.
As shown in FIG. 2, in order to facilitate the fitting of the tip of the driver bit 20, the groove width of each of the cross grooves 12 is formed to be relatively larger than the width of the ridge portion of the extended blade portion 22a of the driver bit 20, and the adjacent one is adjacent. The area of the tapered side wall portion 13 and the tapered coupling surfaces 17a, 17b formed at the boundary portion or the corner portion between the cross grooves 12, 12 are relatively small.
Therefore, in the turning operation of the driver bit 20, the tapered side wall portion 13 and the tapered connecting surface 17a,
When a large amount of stress is applied to 17b and the screw tightening resistance is large, the tapered side wall portion 13 and the tapered coupling surfaces 17a and 17b are gradually damaged as shown by the hatched portion 15 in FIG. Accordingly, when the damaged portion (the hatched portion 15) is enlarged, the cam-out phenomenon of the driver bit 20 becomes frequent, and finally the screw tightening operation becomes impossible.

[0008] From such a viewpoint, in order to prevent the camming phenomenon of the driver bit 20, it is necessary to apply a thrust for strongly pressing the driver bit 20 against the screw groove portion 12a when rotating the driver bit 20. .
However, there is no problem when the object to which the screw is attached is a rigid body such as a metal, but when it is a precision part or the like, there is a disadvantage that these objects are damaged or broken.

Further, the occurrence of the above-mentioned come-out phenomenon is as follows.
The wear of the bit tip portion, that is, the blade portion 22 and the extension blade portion 22a is accelerated, and the wear further promotes the occurrence of the cam-out phenomenon. As a result, the damage of the thread groove also increases.

Furthermore, by applying an excessive thrust to the driver bit 20, it is possible to prevent the cam-out phenomenon, but on the other hand, it is possible to transmit an accurate torque to the screw. However, the magnitude of the thrust applied to the driver bit 20 differs depending on the operator, and as a result, there is a problem that the tightening torque of the screw varies.

Further, in the case of a tapping screw, when the screw is tightened to an object such as a synthetic resin, friction due to thrust is applied in addition to rotational friction of the screw, so that high heat is applied to the object. There is a problem in that the hardness of the screw mounting portion of the object is reduced due to the occurrence, and the loosening of the screw occurs or the object is damaged.

On the other hand, when the screw is manually tightened, the operation of rotating the screwdriver screw 20 while sufficiently pressing the screwdriver against the screw has a drawback that the operator exerts a great deal of labor and fatigue.

Further, according to the combination of the conventional screw 10 and the driver bit 20 described above, when the screw is attached using a manual tool or an electric tool, when the screw tip is fitted to the bit end of the screw groove. However, it is difficult to rotate the screw while maintaining the state where the screw shaft and the driver bit shaft are coaxially matched, and therefore, when the screw shaft and the driver bit shaft are inclined, In addition to the frequent occurrence of the cam-out phenomenon, the thread groove is frequently damaged.

Further, when removing the screw, the same cam-out phenomenon and damage to the screw groove as described above are likely to occur, but in this case, the screw cannot be removed.
A situation arises in which a part of the mounting object of the screw must be destroyed. In particular, if the thread groove is clogged with dust or the like, there is a drawback that the above-mentioned situation becomes remarkable.

Accordingly, an object of the present invention is to improve the configuration of the groove in the cross groove of the screw in the combination of the screw and the driver bit to effectively prevent the cam out phenomenon of the driver bit, and to prevent the breakage of the screw as in the prior art. To provide a combination of a screw and a screwdriver bit that can always achieve proper and quick screw tightening work even if the cross groove portion of the screw is damaged, and can significantly improve work efficiency. It is in.

[0016]

In order to achieve the above object, a screw according to the present invention is provided with a bit fitting groove formed of a cruciform groove in a screw head, and the end of the bit fitting groove is formed at a predetermined depth. The vertical end wall is formed as a vertical bottom wall, and the bottom edge of the vertical end wall is directed toward the center of the screw head to form a flat bottom. In a screw formed by forming a slanted groove portion and forming a substantially conical bottom surface at the intersection center thereof, the bit fitting groove is directed radially outward from the center of the screw head to form a groove. It is characterized in that the width is formed as a substantially divergent groove, and the opening angle of the opposing side wall portion of each adjacent groove is slightly more acute than a right angle.

In this case, the flat bottom of the bit fitting groove is raised from the lower edge of the vertical end wall toward the center of the screw head, and the raised bottom is located at the center of the screw neck. The inclined grooves may be formed to face each other, and a substantially conical bottom surface may be formed at the intersection center of the inclined grooves.

On the other hand, the driver bit adapted to the screw is provided with a flat blade portion having a substantially vertical edge portion which fits along the vertical end wall portion of the bit fitting groove of the screw head at the tip portion. The distal end surface of the blade portion is substantially horizontal, and a projection is provided at the center thereof. Both side walls at the distal end of the flat blade portion are adapted to the substantially divergent groove forming the bit fitting groove of the screw. It is characterized by having a configuration.

In this case, at the both edge portions of the flat blade portion, the edge portion intersecting with the horizontal surface portion at the tip of the blade portion can be formed at a right angle or slightly to the side of the horizontal surface portion to form an acute angle.

The projection formed at the center of the horizontal tip surface of the flat blade portion is adapted to the inclined groove or the conical bottom formed at the center of the bit fitting groove of the screw according to claim 1 or 2. Shape.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a combination of a screw and a driver bit according to an embodiment of the present invention.

FIGS. 1 and 2 show an embodiment of the screw according to the present invention. That is, in FIGS. 1 and 2, reference numeral 30 denotes a screw according to the present invention, and a bit fitting groove 32 is provided in a head 30 a of the screw 30. The bit fitting groove 32 is provided in the center of the screw head 30a so as to be orthogonal to the plus (+) shape.

The bit fitting groove 32 forms a vertical end wall portion 32a having a predetermined depth at an end portion thereof. The lower end portion 32a 'of the end wall portion 32a is located at the center of the screw head 30a. Forming a flat bottom 32b, and then forming the inclined grooves 32c from the flat bottom 32b toward the center of the screw head 30a.
The configuration is such that a substantially conical bottom surface 34 having a gentle inclination is formed at the center of the intersection of c.

Therefore, in the present embodiment, as shown in FIG. 2, the side wall 33 of the bit fitting groove 32 of the screw 30 is directed radially outward from the center of the screw head 30a. A groove 33a having a substantially divergent groove width,
33b.

As described above, in the screw 30 of the present embodiment, by forming the divergent grooves 33a and 33b, the opening angle β of the opposing side wall of each adjacent groove is set to a right angle (90 °). By setting the angle to be slightly more acute, the cam out phenomenon of the screw 30 from the bit fitting groove 32 can be effectively prevented in combination with a driver bit described later.

It should be noted that the side wall 33 has a taper of about 1.5 ° to 2 ° (withdrawal angle of the header punch) between the adjacent bit fitting grooves 32.
At the adjacent corner of the bit fitting groove 32, the opening edge of the bit fitting groove 32 in the screw head 30a from the position of the conical bottom surface 34, similarly to the conventional cross groove screw shown in FIG. The tapered connecting surfaces 37a and 37b extending up to the respective portions are formed. Further, the width of the bit fitting groove 32 is
Although it is configured so as to be adapted to the thickness of the blade portion of the driver bit described later, it is preferable that the configuration is slightly wider than the thickness in consideration of plating coating on the screw surface.

FIG. 3 shows another embodiment of the screw according to the present invention. That is, in the present embodiment, a vertical end wall portion 32a having a predetermined depth is formed at the edge portion of the bit fitting groove 32, and the lower edge portion 3a of the end wall portion 32a is formed.
From 2a ', it is raised toward the center of the screw head 30a to form a non-planar bottom 32b', and then from the raised portion 32b "of the non-planar bottom 32b 'to the center of the screw neck 30b. Each of the inclined grooves 32c is formed, and an approximately conical bottom surface 34 having a gentle inclination is formed at the intersection center of the inclined grooves 32c.

The screw 30 thus constructed according to the present embodiment is provided with non-planar bottoms 32b 'at the edges of the bit fitting grooves 32 of the screw head 30a, and the raised portions of these non-planar bottoms 32b'. By forming the inclined grooves 32c extending from 32b ″ toward the center of the screw neck 30b, the taper contact area with the entire bit fitting groove 32 is partially and reduced, and the adjacent bit is formed. The area of the side wall 33 at the boundary between the fitting grooves 32, where the tip of the driver bit abuts (the area of the surface on which the driver bit applies rotational driving force to the screw, ie, the area of the driving surface) can be increased. .

FIG. 4 shows an embodiment of a driver bit 40 which is compatible with the screw 30 according to the embodiment shown in FIGS. That is, the driver bit 40 of the present embodiment is fitted in the bit fitting groove 32 of the screw 30, and has a vertical end wall portion 32 a formed at the edge of the bit fitting groove 32 and a flat bottom portion 32 b or a non-planar portion. Bottom 32b '
And substantially horizontally extending horizontal surface portions 42 respectively engaged with
a, and the flat bottom portion 32b or the non-planar bottom portion 3 of the bit fitting groove 32 is provided.
2b ', the screw neck 30b
Each of the projections 42b is configured to protrude so as to conform to the shape of the inclined groove 32c formed toward the center of the projection.

In this case, the driver bit 4 of this embodiment is
0, the flat blade portion 42 of the bit fitting groove 32 has a flat blade portion 42 so that the width of the bit fitting groove 32 can be applied to the screws 30 formed so as to be substantially divergent grooves 33a and 33b.
Are formed as shapes that match the divergent grooves 33a, 33b, ie, divergent side walls 43a, 43b.

By forming the side wall portion 43 in this manner, as shown in FIG. 6, when the blade portion 42 of the driver bit 40 and each side wall portion of the bit fitting groove 32 of the screw 30 come into contact with each other, as shown in FIG. Grooves 33a, 33b and side walls 43a, 43
b can be minimized and bit fitting with an appropriate screw can be achieved.

In addition, the driver bit 40 of this embodiment
According to this, at the time of the screw tightening operation, the blade portion 42 of the driver bit 40 and the flared groove 33 of the screw 30 are formed.
a, 33b, each side wall portion (T
1, T2, T3, T4), as shown in FIG. 2, the opening angle β of the opposing side wall of each adjacent groove is set to be slightly more acute than the right angle (90 °). As a result, a balanced torque transmission can be achieved.

In this case, each of the side wall portions (T1, T
2, T3, T4) can be directed more toward the screw neck 30b than the tangential direction .tau.0 of the screw east 30a on which the blade 42 of the driver bit 40 acts. It can be effectively prevented.

FIG. 5 shows a modified example of the driver bit 40 shown in FIG. 4. The both ends 42a 'of the flat blade portion 42 in the driver bit 40 of the above embodiment are shown.
In the above, the edge of the blade portion tip that intersects with the horizontal surface portion 42a is formed at an acute angle by projecting from the right angle to the horizontal surface portion 42a side, and the projection 42b is configured as a vertical projection 42c extending vertically downward. is there. That is, in the driver bit 40 of the present embodiment, the vertical projection 4
By forming the second groove 2c, the inclined groove 32c of the bit fitting groove 32 of the screw 30 in the above-described embodiment is formed.
, So as not to make a taper contact.
By configuring the driver bit 40 in this way, the prevention of the cam-out phenomenon is further ensured.

The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made without departing from the spirit of the present invention. It is.

[0036]

As is apparent from the above-described embodiment, the screw according to the present invention has a bit fitting groove formed of a cruciform groove in the screw head, and the edge of the bit fitting groove is formed to a predetermined depth. Of the screw head from the lower edge of the vertical end wall toward the center of the screw head, forming a flat bottom at the center of the screw neck than the flat bottom. In the case of a screw having a slanted groove and a substantially conical bottom surface at the intersection center thereof, the bit fitting groove is directed radially outward from the center of the screw head to have a groove width. Is formed as an almost divergent groove,
By forming the opening angle of the opposing side wall portion of each of the adjacent grooves to be slightly more acute than the right angle, the taper contact with the entire bit fitting groove at the time of fitting the tip of the driver bit with the bit fitting groove is achieved. The area can be partially and reduced, and the area of the side wall portion where the tip of the driver bit abuts at the boundary between the adjacent bit fitting grooves can be enlarged, thereby reliably preventing the driver bit from coming out. be able to.

Further, the driver bit according to the present invention comprises:
A flat blade portion having a substantially vertical edge portion which fits along a vertical end wall portion of the bit fitting groove of the screw head at a distal end portion is provided. The most suitable for the screw by forming a projection on the both side walls at the tip of the flat blade portion so as to be adapted to the substantially divergent groove forming the bit fitting groove of the screw. Can be obtained.

In the present invention, the use of a header punch provided with a projection or a ridge adapted to the shape of the bit fitting groove of the screw makes it possible to mass-produce the screw simply and at low cost. be able to.

In the screw according to the present invention, when forming the bit fitting groove of the screw head, the non-planar bottom portion raised from the lower edge of the vertical end wall toward the center of the screw head. In the case of forming the screw, it is possible to manufacture a screw having a structure in which the thickness at the time of forming the groove in the screw neck is properly maintained and the strength at the time of tightening or removing the screw is sufficiently maintained.

Further, the screw according to the present invention basically has a configuration in which the taper contact area with the entire bit fitting groove is partially and slightly reduced when the screw is fitted to the driver bit, and the side wall portion at the tip of the driver bit is formed. By enlarging the area of the side wall portion of the bit fitting groove that comes into contact, a cam-out phenomenon also occurs without causing breakage (reference numeral 15) in a part of the bit fitting groove as shown in FIG. 8, for example. Therefore, a proper screw tightening operation and a screw removing operation can be achieved.

Further, according to the combination of the screw and the driver bit according to the present invention, the screw shaft and the bit shaft can always be fitted and rotated on the same axis, so that a cam-out phenomenon, a screw and the like can be prevented. The rotation power of the driver bit 40 is smoothly transmitted to the screw 30 without causing breakage, and the screw tightening operation with an appropriate torque can always be promptly achieved.

That is, if the combination of the screw and the driver bit according to the present invention is used, a reliable screw tightening operation can always be performed with an appropriate torque on an object to which the screw made of various hard and soft materials is to be attached. In addition to this, the breakage of the screw can be greatly reduced, and the safety and efficiency of the screw tightening operation can be easily and economically improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a main part showing an embodiment of a screw according to the present invention.

FIG. 2 is a plan view of the head of the screw shown in FIG. 1;

FIG. 3 is a sectional side view of a main part showing another embodiment of the screw according to the present invention.

FIG. 4 is a main part side view showing one embodiment of a driver bit according to the present invention.

FIG. 5 is a cross-sectional side view of a main part showing a modified example of the driver bit shown in FIG. 4;

FIG. 6 is an explanatory plan view of a screw head showing a coupling state between the screw shown in FIG. 2 and the driver bit shown in FIG. 4;

FIG. 7 is a cross-sectional side view of a main part of a conventional cross groove screw.

FIG. 8 is a plan view of the head of the cross groove screw shown in FIG. 7;

FIG. 9 is a side view of a main part of a conventional driver bit for a cross groove screw.

FIG. 10 is a cross-sectional side view of a main part showing a coupling state between the screw shown in FIG. 7 and the driver bit shown in FIG. 9;

[Explanation of symbols]

 Reference Signs List 30 screw 30a screw head 30b screw neck 32 bit fitting groove 32a vertical end wall 32a 'lower edge 32a "inclined portion 32b flat bottom 32b' non-planar bottom 32b" raised portion 32c inclined groove portion 33 side wall portions 33a, 33b Divergent groove 34 Conical bottom surface 37a, 37b Taper coupling surface 40 Driver bit 42 Flat blade part 42a Horizontal plane part 42a 'Edge part 42b Projection 42c Vertical projection 43 Side wall part 43a, 43b Spread side wall part

Claims (5)

[Claims] 1. A bit fitting groove comprising a cross groove is provided in a screw head, and an edge of the bit fitting groove is formed as a substantially vertical end wall having a predetermined depth. Form a flat bottom from the lower edge toward the center of the screw head,
In a screw formed by forming a slanted groove portion toward the center of the screw neck portion further from the flat bottom portion and forming a substantially conical bottom surface at the intersection center thereof, the bit fitting groove is formed at the center of the screw head. The groove width is formed as a substantially divergent groove extending radially outward from the portion, and the opening angle of the opposing side wall portion of each of the adjacent grooves is configured to be slightly more acute than a right angle. And screw. 2. The flat bottom of the bit fitting groove is raised from the lower edge of the vertical end wall toward the center of the screw head, and is directed from the raised portion toward the center of the screw neck. 2. The screw according to claim 1, wherein each of the inclined grooves is formed so as to have a substantially conical bottom surface at the intersection center of the inclined grooves. 3. A flat blade portion having a substantially vertical edge portion fitted at a tip portion along a vertical end wall portion of a bit fitting groove of a screw head, and a tip surface of the blade portion is substantially horizontal. And a projection formed at the center of the flat blade so that both side walls at the distal end of the flat blade have a shape adapted to the substantially divergent groove forming the bit fitting groove of the screw according to claim 1 or 2. Driver bit characterized by doing. 4. The driver bit according to claim 3, wherein, at both end edges of the flat blade portion, an edge crossing the horizontal surface portion at the tip of the blade portion is formed at a right angle or slightly to the side of the horizontal surface portion to form an acute angle. 5. A projection formed at the center of the horizontal tip surface of the flat blade portion is adapted to an inclined groove or a conical bottom formed at the center of the bit fitting groove of the screw according to claim 1 or 2. 4. The driver bit according to claim 3, wherein the driver bit has a shape.