JP2013121629A - Driver bit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driver bit which reduces a fastening defect caused by oblique fastening by regulating an inclination of a screw.SOLUTION: In the driver bit 10 formed by integrally having an engagement part 11 engaged with a drive hole 91 of the screw 90 and a connecting part 12 connectable to a rotating means having a rotation drive source, a coil spring 14 is made to penetrate the engagement part 11 and one end of the coil spring 14 is fixed by pressure-insertion. By this, since the coil spring 14 is pushed by the head of the screw 90 and compressed, the tip of the engagement part 11 abuts on the bottom of the drive hole 91, core-alignment is applied to the screw 90, and the coil spring 14 always abuts on the head of the screw 90, thus regulating the inclination of the screw 90. By this, since an attitude of the screw 90 can be stabilized at attraction, the oblique fastening of the screw 90 which has frequently occurred at screwing can be reduced.

Description

  The present invention relates to a driver bit used in an automatic screwing machine.

  Conventional driver bits are known from those disclosed in Patent Document 1, and will be described below with reference to FIGS. The conventional driver bit 50 includes an engaging portion 51 that can be engaged with a screw 90 that is an example of a desired component, and a permanent magnet 52 disposed on the outer periphery of the engaging portion 51. The permanent magnet 52 is fixed to the engaging portion 51, and a dish portion 52a is formed on one end face thereof. Further, the dish part 52a is located slightly behind the tip of the engaging part 51, and is configured to be able to guide the head of the screw 90 that has been sucked. The driver bit 50 is connected to a motor (not shown) and an elevating means (not shown), which are an example of a rotational drive source disposed above the screwdriver bit 50, and the screw 90 can be fastened to a predetermined torque. By the way, the driver bit used in the automatic screw tightening machine prevents the biting (engagement between the drive hole 91 and the engaging portion 51) that occurs after the screw 90 is fastened and the time required for the engagement with the drive hole 91 is shortened. In general, the size of the engaging portion 51 is set to be smaller than the size of the drive hole 91. Specifically, if the drive hole 91 is a cross hole, the inclination angle of the engaging portion 51 is set slightly smaller than the inclination angle of the drive hole 91, and if the drive hole 91 is a hexagonal hole, The dimensions of the opposite sides of the engaging portion 51 are set slightly smaller than the opposite sides of the drive hole 91. That is, when the engagement portion 51 is engaged with the drive hole 91, there is a slight gap W 2 between the opening portion of the drive hole 91 and the engagement portion 51 regardless of the type of the drive hole 91. Arise. The driver bit 50 configured in this manner rotates in response to the rotation of the motor and attracts the screw 90 by the magnetic force of the permanent magnet 52. As a result, the engagement between the engaging portion 51 and the drive hole 91 is completed, and the driver bit 50 is lowered and screwed into the workpiece while rotating integrally with the screw 90 adsorbed.

Japanese Patent Laid-Open No. 05-337840

  In the conventional driver bit 50, since the permanent magnet 52 is fixed to the outer periphery of the engaging portion 51, the axial positional relationship between the plate portion 52a of the permanent magnet 52 and the engaging portion 51 is always constant. It has become. As a result, as shown in FIG. 4, if the drive hole 91 is formed in a cross hole and the depth F of the cross hole is a deep screw 90, the countersink 52a and the head of the screw 90 abut, Since the dish portion 52a serves as a stopper, the tip of the engagement portion 51 does not fit to the back of the drive hole 91. That is, a gap H is generated between the tip of the engaging portion 51 and the bottom of the drive hole 91. As a result, when the torque related to the engaging portion 51 increases, the engaging portion 51 has a problem of being pushed up above the screw 90 (hereinafter referred to as “camout”) and cannot reach a predetermined torque. . Although not shown, for example, if the drive hole (91) is formed in a hexagonal hole and the depth (F) of the hexagonal hole is deep, the plate part (52a) of the permanent magnet (52) is the same as described above. And the head of the screw (90) come into contact with each other, and the tip of the engaging portion (51) does not fit to the back of the drive hole (91). Therefore, when the screw tightening is started, the driver bit 50 has a shallow engagement depth between the engagement portion 51 and the drive hole 91, and the engagement area is smaller than a normal one. There is also a problem that causes a phenomenon of scraping the hole 91 (hereinafter referred to as “ream out”).

  On the other hand, as shown in FIG. 5, in the case of the screw 90 having a shallow depth F of the drive hole 91, although the tip of the engagement portion 51 fits in the back of the drive hole 91, A gap W1 is created between the heads, and a gap W2 is created between the opening of the drive hole 91 and the engaging part 51. That is, when the screw 90 is attracted, the screw 90 is supported by the tip of the engaging portion 51, the tip of the screw 90 is easily swung in the direction of the arrow Y1, and the axis of the screw 90 is There is also a problem in that it is tightened while being tilted with respect to the axis of the engaging portion 51 to be obliquely tightened. Although the shape of the drive hole 91 in FIG. 5 is a cross hole, other shapes have the same problem as the cross hole.

  By the way, the permanent magnet 52 is fixed to the outer periphery of the engaging portion 51. As the fixing method, adhesion, shrink fitting, brazing, or the like is employed. However, in the bonding, there is a problem that the permanent magnet 12 drops from the engaging portion 51 due to deterioration of the adhesive solvent or the like. Moreover, in shrink fitting or brazing, since the engaging portion 51 and the permanent magnet 12 are heated, there is a problem that the respective hardness is lowered than originally.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a driver bit that regulates the inclination of a screw and reduces fastening failure due to oblique fastening. In order to achieve this object, the present invention provides a driver bit that integrally includes an engaging portion that can be engaged with a drive hole of a desired component and a connecting portion that can be connected to a rotating means having a rotational drive source. The elastic member is inserted into the engaging portion, and one end of the elastic member is fixed, while the other end is a free end and can be moved along the axis of the engaging portion. The elastic member is preferably a coil spring. On the other hand, it is desirable that the length of the elastic member is set to a dimension such that the tip of the engaging portion protrudes from the free end of the elastic member. Furthermore, it is preferable that the length of the elastic member is set to a dimension in which the free end of the elastic member and the engaging portion are brought into contact with the desired component when the driving hole and the engaging portion are engaged.

  According to the driver bit 10 of the present invention, when the tip of the screw 90 comes into contact with the fastening object 96, the coil spring 14 is pressed by the head of the screw 90 and compressed, so that the depth of the drive hole 91 is increased. Even when F is deep, the tip of the engaging portion 11 is fitted to the back of the drive hole 91. Therefore, the driver bit 10 has an advantage that the occurrence of the reaming or the camout can be reduced and the screw 90 can be surely screwed into the fastening object 96. The driver bit 10 is compressed by the coil spring 14 being pushed by the head of the screw 90, so that the tip of the engaging portion 11 abuts the bottom of the drive hole 91 to align the screw 90. At the same time, since the coil spring 14 is always in contact with the head of the screw 90, the screw 90 is regulated so as not to tilt. Accordingly, since the driver bit 10 suppresses the inclination of the screw 90 when the screw 90 is attracted, there is an advantage that the occurrence of oblique tightening can be reduced. Further, since one end of the coil spring 14 is press-fitted into the groove 11a, there is an advantage that a problem due to conventional bonding, shrink fitting or brazing does not occur.

1 is an external view of an embodiment according to the present invention. It is an external view of another Example concerning this invention. It is a partially notched screw tightening operation explanatory view of the driver bit of the present invention. It is a partially cut screw tightening operation explanatory view of a conventional driver bit. It is a partially cut screw tightening operation explanatory view of a conventional driver bit.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The driver bit 10 includes an engagement portion 11 that can be engaged with the screw 90, a connection portion 12 that can be connected to a rotation means (not shown) having a rotation drive source (hereinafter referred to as a motor), and the engagement. A cylindrical cylindrical shaft portion 13 that connects the portion 11 and the connecting portion 12 and a coil spring 14 that is an example of an elastic member disposed on the outer periphery of the engaging portion 11.

  The engaging portion 11 is provided with a groove 11a having an R-shaped cross section on the outer periphery thereof, and this groove 11a is formed near the boundary between the engaging portion 11 and the cylindrical shaft portion 13. The engaging portion 11 is formed in a cross shape in FIG. 1, and in a Torx (registered trademark) shape in FIG. 2, and is not limited to these shapes. Needless to say, it is set as appropriate to match the shape of the drive hole. Further, since the driver bit 10 of the present invention is used in an automatic screw tightening machine, the size of the engaging portion 11 is set smaller than the size of the drive hole 91 of the screw 90 as in the conventional case.

  The connection portion 12 is formed with a male screw in the case of FIG. 1 and is formed in a hexagonal bar shape in the case of FIG. 2, but is not limited to these shapes, and can be connected to the rotating means. If it is good.

  The cylindrical shaft portion 13 is configured such that the axis thereof communicates with the respective axis lines of the engaging portion 11 and the connecting portion 12, and is the same member as the engaging portion 11 and the connecting portion 12. In addition, it is configured as a single object.

  The coil spring 14 is fixed so that one end of the coil spring 14 is press-fitted into the groove 11a and does not fall off from the groove 11a, and the other end (hereinafter referred to as a free end) extends along the axis of the engaging portion 11a. It is comprised so that it can move to 11a side. Further, since the length of the coil spring 14 is set such that the tip of the engaging portion 11 protrudes from the free end, the protruding engaging portion 11 is driven when the screw 90 is sucked. The hole 91 can be invited. Further, the length of the coil spring 14 is such that the tip of the engaging portion 11 is in contact with the bottom of the drive hole 91 when the screw 90 is attracted, and the free end is always in contact with the head of the screw 90. Set to dimensions.

  By the way, as shown in FIG. 3, the screw 90 is sucked by a suction pipe 80 formed of a hollow shaft and an air suction device (not shown) connected to the inner diameter of the suction pipe. The suction pipe 80 is set to have an inner diameter slightly larger than the head of the screw 90 and includes the driver bit 10. Since there are many well-known documents for performing the screw 90 by sucking air in this way, description thereof is omitted here.

  Next, the operation will be described below with reference to FIG. Upon receiving a command from a control device (not shown) or the like, the output shaft of the motor rotates, and the driver bit 10 rotates by the rotation of the output shaft. Further, since the air suction device is activated simultaneously with the rotation of the driver bit 10, the screw 90 is sucked into the suction pipe 80 from its head. As a result, the free end of the coil spring 14 is pushed upward by the head of the screw 90 and moves upward, so that the tip of the engagement portion 11 abuts against the bottom of the drive hole 91. This is because the coil spring 14 supports the vicinity of the opening of the drive hole 91 and the engaging portion 11 supports the back of the drive hole 91. In other words, the driver bit 10 simultaneously performs the alignment of the screw 90 by the engaging portion 11 and the restriction of the inclination of the screw 90 by the coil spring 14, and the contact portion of the screw 90 is at the time of conventional suction. There is an increase in characteristics. Therefore, the axis of the screw 90 at the time of suction does not greatly tilt with respect to the axis of the driver bit 10. Further, the driver bit 10 descends together with the suction pipe 80 while the screw 90 engaged in the correct posture is held in the suction pipe 80, and the tip of the suction pipe 80 is fastened as shown in FIG. It contacts the surface of the object 95. Thereafter, only the rotating driver bit 10 is lowered, and the tip of the screw 90 is brought into contact with a tap hole formed in the fastener 96. Thereby, since the screw 90 is screwed in substantially in line with the axis of the tap hole, the torque during screwing into the tap hole is minimized.

  As described above, according to the driver bit 10 of the present invention, when the tip of the screw 90 comes into contact with the fastener 96, the free end of the coil spring 14 is pushed by the head of the screw 90 and Since it moves to the connection part 12 side, even if the depth F of the drive hole 91 is deep, the engaging part 11 is fitted to the back of the drive hole 91. Therefore, the driver bit 10 has an advantage that the occurrence of the reaming or the camout can be reduced and the screw 90 can be surely screwed into the fastening object 96. The driver bit 10 is compressed by the coil spring 14 being pushed by the head of the screw 90, so that the tip of the engaging portion 11 abuts the bottom of the drive hole 91 to align the screw 90. At the same time, since the coil spring 14 is always in contact with the head of the screw 90, the screw 90 is regulated so as not to tilt. Accordingly, since the driver bit 10 suppresses the inclination of the screw 90 when the screw 90 is attracted, there is an advantage that the occurrence of oblique tightening can be reduced. Further, since one end of the coil spring 14 is press-fitted into the groove 11a, there is an advantage that a problem due to conventional bonding, shrink fitting or brazing does not occur.

10 Driver bits (present invention)
11 Engagement part (present invention)
11a Groove 12 Connection 13 Cylindrical Shaft 14 Coil Spring 50 Driver Bit (Conventional)
51 engaging part (conventional)
52 Permanent magnet 52a Countersunk part 80 Adsorption pipe 90 Screw 91 Drive hole 95 Fastening thing 96 Fastening thing F Depth H Gap W1 Gap W2 Gap Y1 Arrow

Claims (4)

In a driver bit integrally including an engaging portion that can be engaged with a drive hole of a desired part and a connection portion that can be connected to a rotating means including a rotation drive source,
A driver bit, wherein an elastic member is inserted into the engaging portion, and one end of the elastic member is fixed, while the other end is a free end and can be moved along the axis of the engaging portion.   The driver bit according to claim 1, wherein the elastic member is a coil spring.   3. The driver bit according to claim 1, wherein the length of the elastic member is set to a dimension in which a tip of the engaging portion protrudes from a free end of the elastic member.   The length of the elastic member is set to a dimension such that a free end of the elastic member and the engaging portion are brought into contact with the desired part when the driving hole and the engaging portion are engaged. The driver bit according to claim 1.

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