JP6523043B2 - Tap - Google Patents

Description

  The present invention relates to a tap for forming a female screw in a nut.

  When the tap used for tapping of the female screw is long in size, it is difficult to manufacture it as a unit due to the convenience of the tap manufacturing machine. Therefore, in the manufacture of such a tap, the parts are often manufactured separately. That is, as shown in FIG. 4, the shank member 103 having the male screw portion 105 at its tip and transmitting the cutting rotational force, and the blade member 102 having the male screw portion 105 at the base end and cutting the female screw are separately provided. The tap 101 is manufactured by screwing these into the inner peripheral portion through the hollow round rod-like joint member 104 having the internal thread portion 106 on the inner peripheral surface and integrating them with each other (for example, patent) Reference 1).

Japanese Utility Model Publication No. 44-8237

  In the tap, maintenance is periodically performed to regrind the cutting edge member worn by repeated use. Even in such a case, it is necessary to disassemble the tap for the convenience of the maintenance machine. However, in the method of screwing in and joining the cutting edge member and the shank member through the joint member as described above, the load due to the cutting rotational force when using a tap causes excessive tightening by screwing, and these are easily disassembled There is a problem that you can not do it.

  Then, an object of the present invention is to provide a tap in which disassembling of the cutting edge member, the shank member, and the joint member is easy even after being subjected to tapping work in which a large torque is transmitted.

In order to achieve this object, the invention according to claim 1 is
A cutting edge member for cutting a female screw, a shank member for transmitting a cutting rotational force, and a joint member for connecting the cutting edge member and the shank member at one end and the other end;
A tap that comprises
The cutting edge member and the joint member are connected by fitting the first fitting portion of the non-circular cross section formed in the cutting edge member and the first fitting portion formed in the joint member.
The shank member and the joint member are connected by the second fitting portion of the non-circular cross section formed on the shank member and the second fitting portion formed on the joint member being fitted with each other.
The blade edge member and the shank member are respectively provided with first and second contact surfaces which come into contact with the end face of the joint member when the first and second fitting portions and the first and second fitting portions are fitted. And the first and second inclining portions are provided on the surfaces of the first and second fitting portions, respectively, with the first and second inclined surfaces inclined outward in the circumferential direction according to the depth of the joint member,
The joint member is provided with first and second female screw holes,
The first and second female screw holes are provided with first and second push screws respectively threadedly inserted into the first and second female screw holes,
The blade tip member, the shank member, and the joint member are joined by pressing the first and second inclined surfaces by screwing the first and second push screws, respectively.

The invention according to claim 2 is
A tap according to claim 1, wherein
The first and second inclined surfaces are formed by the bottoms of the first and second drill holes formed in the first and second fitting parts,
The axial centers of the first and second female screw holes and the axial centers of the first and second drill holes are offset in the longitudinal direction of the joint member when the end face and the contact surface come into contact at the time of fitting. It is characterized by

  According to the present invention, when the first and second fitting parts and the first and second fitting parts are respectively fitted, the end faces of the one end and the other end of the joint member and the first and second contact surfaces By making contact with each other, the blade edge member and the shank member do not enter the back of the joint member any more. Furthermore, the first and second inclined surfaces are pressed by the first and second push screws, respectively, to apply a force to the cutting edge member and the shank member toward the back of the joint member. By these actions, the blade tip member, the shank member, and the joint member can be strongly tightened, and the blade tip member, the shank member, and the joint member can be firmly joined.

  Further, in the present invention, in which the blade edge member, the shank member, and the joint member are connected by being fitted to each other and joined firmly by the push screw as described above, the cutting rotational force at the time of tapping becomes excessive. Tightening does not occur. This is because the tightening of each member is not affected by the cutting torque. For this reason, after loosening tightening by pulling out a push screw, since each member can be parted by pulling out each fitted member, a tap can be disassembled easily.

  Further, since the blade edge member and the joint member, and the shank member and the joint member are all connected by fitting using a non-circular cross-sectional member, torque can be reliably transmitted at the connection portion. Thus, the shank member can transmit the cutting rotational force to the cutting edge member via the joint member.

It is a front fragmentary sectional view of a tap concerning an embodiment of the invention. It is a principal part expansion partial sectional view of the tap. It is AA sectional drawing in FIG. (A) is a figure which shows the blade edge member which concerns on the conventional tap, a shank member, and a coupling member. (B) is a figure which shows the time of joining of the blade-edge member which concerns on the same tap, a shank member, and a coupling member.

  The entire configuration of a tap according to an embodiment of the present invention will be described based on FIG. The tap 1 according to the present embodiment is an assembly type, is connected to an automatic tapping machine, and transmits a rotational force of the tapping machine, and a work piece called a blank (hereinafter simply referred to as a workpiece) It consists of a cutting edge member 2 for cutting a workpiece to form a female screw, and a joint member 4 provided between the cutting edge member 2 and the shank member 3 and joining these.

  Thus, the tap 1 for cutting the female screw using an automatic tapping machine is covered by the blade portion 20 provided at the end opposite to the end joined to the joint member 4 in the blade member 2. The workpiece is cut.

  Then, the cut workpiece is discharged as it is through the outside of the blade member 2, the joint member 4 and the shank member 3 (hereinafter, the tip of the workpiece on which the workpiece passes through is a tip end , The downstream side is the proximal end). Hereinafter, each member will be described mainly based on FIGS. 1 and 2.

  For example, high-speed steel is used as the material of the blade member 2 and its hardness is about 60 HRC. As described above, at the tip of the blade member 2, the blade 20 is provided with a predetermined length from the tip. Thus, the workpiece is cut to form a female screw.

  A first fitting portion 21 is formed at the proximal end of the blade member 2. Further, on the tip end side of the first fitting portion 21, a first axial center adjusting portion 25 which is a circular cross section is formed.

  The first fitting portion 21 is to be coupled with the first fitting portion 41 formed in the joint member 4 as will be described later, thereby connecting the blade tip member 2 and the joint member 4 to each other. The first contact surface 22 is formed in contact with the tip end surface 43a of the joint member 4 at the time of connection.

  As shown in FIG. 3, the first fitting portion 21 is formed in a square, which is an example of a quadrangle orthogonal to the axial center. Further, in the first fitting portion 21, first drill holes 23 cut inward from an outer circumferential direction are formed in each of four side surfaces constituting a rectangular cross section.

  Since the first drilled hole is formed by the bottom of the drilled hole, it is a conical hole, and its opening angle is, for example, 120 °. At the bottom of the conical first drilled hole 23, a 120 ° opening forms a first inclined surface 24 which is inclined outward in the circumferential direction according to the depth of the joint member 4.

  Like the blade member 2, the shank member 3 is made of, for example, high-speed steel having a hardness of approximately 60 HRC. The shank member 3 is connected at its proximal end to an automatic tapping machine.

  A second fitting portion 31 is formed at the tip of the shank member 3. Further, on the proximal end side of the second fitting portion 31, a second axial center adjusting portion 35 which is a circular cross section is formed.

  The second fitting portion 31 couples the shank member 3 and the joint member 4 by being fitted to a second fitting portion 42 formed on the joint member 4 as described later. The second contact surface 32 is formed in contact with the proximal end surface 44b of the joint member 4 at the time of connection.

  The second fitting portion 31 is formed in a square, which is an example of a square, in a cross section perpendicular to the axis. Further, in the second fitting portion 31, a second drilled hole 33 is formed in each of the four side surfaces constituting the rectangular cross-section, the second drilled hole 33 being cut inward from the outer circumferential direction.

  Since the second drilled hole 33 is formed by the bottom of the drilled hole, it is a conical hole, and its opening angle is, for example, 120 °. At the bottom of the conical second drilled hole 23, a 120 ° opening forms a second inclined surface 24 that is inclined outward in the circumferential direction according to the depth of the joint member 4.

  The joint member 4 has a substantially cylindrical shape, and is made of, for example, chromium molybdenum steel or high carbon chromium bearing steel, and the hardness thereof is about 45 HRC.

  A first fitting portion 41 is formed on the tip side of the center of the joint member 4 in the axial direction. A tip 43 is formed at the tip. A distal end surface 43a is formed at the most distal end of the distal end portion 43, and a first axial center adjustment hole 43b is formed in the vicinity of the distal end surface 43a.

  A second fitting portion 42 is formed on the proximal side with respect to the axial center of the joint member 4. A proximal end 44 is formed at the proximal end. A proximal end face 44a is formed at the most proximal end of the proximal end portion 44, and a second axial center adjustment hole 44b is formed in the vicinity of the proximal end face 44a.

  Further, the joint member 4 is formed with first and second female screw holes 45, 46 penetrating in the circumferential inward direction. In the present embodiment, a total of four first female screw holes 45 are formed, which correspond to the number of holes 23 of the first drill described above. Similarly, in the present embodiment, a total of four second female screw holes 46 are formed, which correspond to the number of second drill holes 33 described above.

Next, the assembly at the time of assembly of the tap 1 according to the present embodiment will be described based on FIG.
The tap 1 is assembled by joining the blade member 2 and the shank member 3 by the joint member 4. The blade member 2 and the joint member 4 are connected by the first fitting portion 21 and the first fitting portion 41 being fitted. At this time, the contact between the first contact surface 22 and the tip end surface 43 a of the joint member 4 prevents the blade member 2 from entering the back of the joint member 4 any more.

  Further, the shank member 3 and the joint member 4 are connected by the second fitting portion 31 and the second fitting portion 42 being fitted. At this time, the contact between the second contact surface 32 and the base end surface 44 b of the joint member 4 prevents the shank member 3 from entering the back of the joint member 4 any more.

  Thus, when the cutting edge member 2, the shank member 3 and the joint member 4 are fitted, a gap 10 is formed in the axial direction between the cutting edge member 2 and the shank member 3 in the inner peripheral portion of the joint member 4. . The formation of the gap 10 restricts the insertion of the cutting edge member 2 and the shank member 3 into the back of the joint member 4 because the contact between the first contact surface 22 and the distal end surface 43a, and Only the contact between the second contact surface 32 and the base end surface 44b is achieved.

  Further, in the connection between the blade member 2, the shank member 3 and the joint member 4, the outer diameters of the first and second shaft center adjusting portions 25 and 35 are the first and second shaft center adjusting holes 43 a and 44 b. The axial center of each member can be matched because it is equal to the inner diameter of. That is, the first and second axial adjustment parts 25 and 35 and the first and second axial adjustment holes 43a and 44b play a role of centering.

  Further, in the blade member 2 and the joint member 4 fitted as described above, the first push screw 5 may be inserted into the first female screw hole 45 and may be in contact with the first inclined surface 24. Is screwed. Thus, the first female screw hole 45 has a circumference of the first drill hole 23 so that the first push screw 5 passing through the first female screw hole 45 contacts the first inclined surface 24. It arranges outward respectively. Here, the first female screw hole 45 is not only disposed outside the circumferential direction of the first drill hole 23, but the screw hole axis 7 of the first female screw hole 45 is the first drill hole. It is disposed at the back of the joint member 4 with respect to the 23 drill hole axial centers 8. Thereby, when the first push screw 5 is passed through the first female screw hole 45, it can be reliably in contact with the first inclined surface 24.

  Furthermore, when the first push screw 5 in contact with the first inclined surface 24 is strongly screwed in, the first inclined surface 24 is moved by the first push screw 5 as shown by the arrow in FIG. A force in the direction acts. Further, the circumferential inward force is decomposed by the first inclined surface 24 into the force in the proximal direction of the cutting edge member 2. That is, the force in the direction of the base end of the blade member 2 acts on the blade member 2 such that the force enters the back of the joint member 4.

  The fitting of the shank member 3 and the joint member 4 is also performed in the same manner as the fitting of the blade member 2 and the joint member 4. That is, the second female screw 46 is screwed into the second female screw hole 46 and can be in contact with the second inclined surface 34. The second female screw hole 46 has a circumference of the second drill hole 33 so that the second push screw 6 thus passing through the second female screw hole 46 contacts the second inclined surface 34. It arranges outward respectively. Here, the second female screw hole 46 is not merely disposed outside the circumferential direction of the second drill hole 33, but the screw hole axial center 7 of the second female screw hole 46 is the second drill hole The joint member 4 is disposed so as to be offset to the back of the joint member 4 with respect to the drill hole axis 8 of 33. Thereby, when the second push screw 6 is passed through the second female screw hole 46, it can reliably contact the second inclined surface 34.

  Further, when the second push screw 6 in contact with the second inclined surface 34 is strongly screwed in, the second inclined surface 34 is inscribed in the circumference by the second push screw 6, as shown by the arrow in FIG. A force in the direction acts. Further, the force in the circumferential inward direction is decomposed by the second inclined surface 34 into a force in the distal direction of the shank member 4, such that the force entering the back of the joint member 4 in the shank member 4 is generated. Works.

  As described above, a force acts on the cutting edge member 2 and the shank member 3 so as to penetrate the joint member 4 with respect to each other. However, as described above, the contact between the first contact surface 22 and the distal end surface 43a and the penetration of the joint member 4 to the back by the second contact surface 32 and the base end surface 44b are restricted. Therefore, these actions combine and the blade member 2, the shank member 3 and the joint member 4 are firmly tightened.

  Here, for example, hexagonal socket bolts are used for the first and second push screws 5 and 6. Therefore, when screwed in, the end portions of the first and second push screws 5, 6 can be made to not protrude outward in the circumferential direction of the first and second female screw holes 45, 46. Therefore, even after the first and second push screws 5, 6 are screwed in, the surface of the joint member 4 is smooth without the end of the screw protruding. As a result, the workpiece cut by the blade member 2 can be smoothly flowed to the proximal end of the shank member 3 without being hooked on the end of the screw.

  The first and second push screws 5, 6 do not have to be hexagonal socket bolts, and the screw ends are out of the circumference when screwed into the first and second female screw holes 45, 46. It is sufficient if it is an aspect that does not protrude in the direction.

  The tap 1 assembled as described above is connected to an automatic tapping machine and receives a rotational force from the automatic tapping machine to perform tapping. The situation at the time of tapping will be described below.

  In the tap 1, as described above, the shank member 3 and the joint member 4 are connected by the fitting of the second fitting portion 31 and the second fitting portion 42 which are square cross sections. Therefore, in the shank member 3, the rotational force given by the automatic tapping machine can be received by the second fitting portion 31 which is a square cross section. Thus, the rotational force can be transmitted from the shank member 3 to the joint member 4.

  Further, the blade edge member 2 and the joint member 4 are connected by fitting the first fitting portion 21 and the first fitting portion 41, which are square cross sections. Therefore, as described above, the rotational force transmitted to the joint member 4 applies a load to the first fitting portion 21 which is a square cross section. Thus, the rotational force can be transmitted from the joint member 4 to the blade member 2.

  That is, the shank member 3 which has received the rotational force from the automatic tapping machine can transmit the cutting rotational force to the cutting edge member 2 through the joint member 4.

  Thus, the cutting edge member 2 to which the cutting rotational force is transmitted rotates around the axis. A workpiece is pushed by a pressing rod or the like from the axial center extension line of the rotating cutting edge member 2 along the axial center extension line and guided to the cutting edge member 2. An internal thread is formed on the inner peripheral surface of the workpiece guided to the blade member 2 by the blade portion 20 provided at a predetermined length from the tip of the blade member 2.

  The workpiece in which the internal thread is formed by the blade portion 20 is discharged as it is through the outside of the joint member 4 and the shank member 3. As described above, the tap 1 capable of integrally forming and discharging the female screw on the workpiece can form a plurality of nuts continuously without stopping the machine.

  Next, the decomposition of the tap 1 will be described. In disassembling, first, the first and second push screws 5, 6 are removed from the first and second female screw holes 45, 46. At this time, the first and second push screws 5 and 6 do not have excessive tightening due to the influence of the cutting rotational force at the time of tapping. This is because the screwing of the first and second push screws 5, 6 is irrelevant to the cutting rotational force. Therefore, the first and second push screws 5, 6 free of excessive tightening can be easily removed.

  Further, since the blade member 2, the shank member 3 and the joint member 4 from which the first and second push screws 5 and 6 have been pulled out are only fitted and connected, they can be easily pulled out.

  That is, the tap 1 can be easily disassembled into the blade member 2, the shank member 3 and the joint member 4.

  Although the tap connected to the automatic tapping machine has been described above as an example, the aspect of the present invention is not limited to this. For example, it may be a hand tap for manual tapping. The type of tap may be, for example, a bent tap or a straight tap.

DESCRIPTION OF SYMBOLS 1 tap 2 blade edge member 20 blade part 21 1st fitting part 22 1st contact surface 23 1st drill hole 24 1st inclined surface 25 1st axial center adjustment part 3 shank member 31 2nd fitting part 32 Second contact surface 33 Second drill hole 34 Second inclined surface 35 Second axial center adjustment portion 4 Joint member 41 First fitting portion 42 Second fitting portion 43 Tip portion 43a Tip surface 43b First axis adjustment hole 44 Base end 44a Base end face 44b Second axis adjustment hole 45 First female screw hole 46 Second female screw hole 5 First push screw 6 Second push screw 10 Clearance portion

Claims (2)

A cutting edge member for cutting a female screw, a shank member for transmitting a cutting rotational force, and a joint member for connecting the cutting edge member and the shank member at both ends;
A tap that comprises
The cutting edge member and the joint member are connected by fitting the first fitting portion of the non-circular cross section formed in the cutting edge member and the first fitting portion formed in the joint member.
The shank member and the joint member are connected by the second fitting portion of the non-circular cross section formed on the shank member and the second fitting portion formed on the joint member being fitted with each other.
The blade edge member and the shank member are respectively provided with first and second contact surfaces which come into contact with the end face of the joint member when the first and second fitting portions and the first and second fitting portions are fitted. And the first and second inclining portions are provided on the surfaces of the first and second fitting portions, respectively, with the first and second inclined surfaces inclined outward in the circumferential direction according to the depth of the joint member,
The joint member is provided with first and second female screw holes,
The first and second female screw holes are provided with first and second push screws respectively threadedly inserted into the first and second female screw holes,
A tap characterized in that the blade edge member, the shank member and the joint member are joined by pressing the first and second inclined surfaces respectively by screwing in the first and second push screws. The first and second inclined surfaces are formed by the bottoms of the first and second drill holes formed in the first and second fitting parts,
The axial centers of the first and second female screw holes and the axial centers of the first and second drill holes are offset in the longitudinal direction of the joint member when the end face and the contact surface come into contact at the time of fitting. The tap according to claim 1, characterized in that:

Images