JPH0214913Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a coupling device for connecting a shank and a tool head etc. that can be detachably attached to the shank.

(Prior art and its problems) When a tool head 3 with a boring tool 2 set thereon is directly connected to a shank 1 as shown in FIG. 1, or when it is connected via an extension attachment 4 as shown in FIG. shank tool head 3
When joining the tool head 3, extension attachment 4, etc. to the shank 1, the parts to be joined must be held exactly concentrically with respect to the shank 1, and the parts to be joined and the shank must be mutually connected between the opposing end surfaces. Pressure contact is an essential condition, and the two must be rigidly connected in a completely concentric manner to completely prevent center runout of the joined members during use.

The conventional connection structure between the shank and the connected member is
For example, as shown in FIG. 3, a cylindrical protrusion 6 that precisely fits into a cylindrical recess 5 concentrically formed in the shank 1 based on a slight dimensional difference is attached to the tool head 3.
A concave peripheral wall 1a of the shank 1 is screwed into a tapered hole 8 formed in the radial direction in the protruding part 6, and is threaded through the concave peripheral wall 1a of the shank 1 in the radial direction. By press-fitting the tapered tip 9a of the connecting pin 9,
The shank end face 10 was configured to be brought into pressure contact with the end face 11 of the member to be joined around the protrusion.
In such a configuration, the shank 1 and the member to be coupled 7
Although it is possible to make surface contact with each other in the axial direction at the end faces 10 and 11 facing each other, the centering accuracy of the member 7 to be coupled with respect to the shank 1 is insufficient. This is because, no matter how precisely the recess 5 and protrusion 6 can be finished, in order to fit them into each other, there must be a dimensional difference, however slight, between them. Within this range, as the coupling pin 9 is press-fitted, the protrusion 6 will be biased to one side of the recess 5.

In order to solve the above problems, for example, as shown in FIG.
At the same time, a tapered part 13 is formed at the base of the protruding part 6 to fit and abut the tapered part 12, and a bolt 14 for drawing the joined members on the shank 1 side is formed on the protruding part 6 of the joined member 7. By screwing into the screw hole 15 and forcibly pulling the member 7 toward the shank 1, both the tapered portions 12 and 13 are brought into fitting contact with each other, and at the same time, the shank side end surface 10 and the member to be joined are screwed into the screw hole 15. Although a coupling structure in which the tapered parts 12 and 13 and both end surfaces 10 and 11 can be brought into pressure contact with each other at the same time has been considered, it is extremely difficult to process the tapered parts 12 and 13 and the end faces 10 and 11 at the same time. The drawback was that it required advanced processing technology.

Various coupling structures are known in addition to the conventional examples illustrated in FIGS. 3 and 4 above, but all of them
Although it completely satisfies the two conditions described above, it is not a practical bonding structure that can be easily implemented.

(Means for Solving the Problems) The present invention has been made to solve the conventional problems as described above, and the reference numerals of the embodiments to be described later are also written in parentheses to indicate their characteristics. In other words, the shank 1 and the members to be joined [tool head 3, etc.]
A concave portion 5 is provided concentrically on one side, and a protruding portion 6 that fits into the concave portion 5 is concentrically provided on the other side, and the end surface 10 on the shank side and the end surface 11 on the side of the joined member are pressed together. The protruding portion 6 is drawn inward in order to , 23, bolt 14
, a recess 24 , and a protrusion 25 ], the coupling device is held around the base of the protrusion 6 by a retainer 16 and is attached to the outer circumferential surface 6 of the protrusion 6 .
A plurality of spheres 17 in the circumferential direction are arranged in contact with a,
The group of spheres 17 is configured to be movable within a certain range in the axial direction of the protrusion 6 together with the retainer 16, and the group of spheres 17 is urged toward the tip of the protrusion 6 via the retainer 16. A biasing means [rubber spring 19] is provided at the entrance of the recess 5, and a spherical circumferential surface 20 whose diameter is constant in the axial direction and whose diameter is slightly smaller than the diameter of the virtual circle circumscribing the group of spheres 17 is formed at the entrance of the recess 5. That's what I did.

(Example) In the following embodiments of the present invention and modifications shown in FIGS. 8 to 10, the same parts as in the conventional example described above are given the same reference numerals, and explanations thereof will be omitted.

In the embodiment shown in FIGS. 5 to 7, the protrusion 6 has a tapered hole 8, similar to the conventional example shown in FIG.
A coupling pin 9 is screwed into the shank peripheral wall 1a. Furthermore, the cylindrical protrusion 6
A plurality of circumferential spheres (steel balls) 17 held by a ring-shaped retainer 16 are disposed on the outer periphery of the base. Each of these spheres 17 has a protrusion outer peripheral surface 6
It is movable in the axial direction of the protrusion together with the retainer 16 while in contact with a. 18 is a snap spring fitted and fixed to the protrusion 6;
The movement of the retainer 16 in the direction of the distal end is restricted. Reference numeral 19 denotes a rubber spring that urges the retainer 16 in a direction to bring it into contact with the snap spring 18. A coil spring may be used instead of this rubber spring 19. Reference numeral 20 denotes an inscribed peripheral surface having a constant inner diameter in the axial direction, which is formed by expanding the diameter of the entrance portion of the recess 5, and has an inner diameter D1.
is the diameter D2 of the virtual circle circumscribing the group of spheres 17
It is finished with a slightly smaller diameter (for example, about 0.01 to 0.02 mm). Note that the inner diameter d1 of the recess 5 is the same as that of the protrusion 6.
It is sufficient if the diameter is suitably larger than the outer diameter d2 of.

According to the above configuration, the protrusion 6 of the member 7 to be coupled
each sphere 1 by inserting it into the recess 5 of the shank 1.
7 comes into contact with the inlet side edge of the spherical internal circumferential surface 20 in the recess 5 . From this state, in order to insert the protrusion 6 deeper, by applying force in the axial direction between the two 1 and 7 in an appropriate manner, the inner circumferential surface 20 of the sphere and the outer circumferential surface 6a of the protrusion 6a are brought into contact with the sphere 17, respectively. Although each sphere 17 is accompanied by a slight local deformation at a location or a slight deformation (deformation into a polygon) of the entire annular portion forming the sphere inner circumferential surface 20 of the shank peripheral wall 1a, each sphere 17 has a sphere inner circumferential surface. 20 will enter inside. At this time, each sphere 17 is connected to the retainer 16.
Since each sphere 17 is biased toward the tip of the protrusion by the rubber spring 19 via the retainer 16, each sphere 17 does not slide backward on the outer circumferential surface 6a of the protrusion, and each sphere 17 can rotate on its own axis. It is possible to enter the inner side of the inner circumferential surface 20 of the sphere.

Each of the spheres 17 that has entered the inside of the sphere inner peripheral surface 20 is moved against the sphere inner peripheral surface 20 and the projection outer peripheral surface 6a as the recess 5 and the protrusion 6 move relative to each other in the axial direction. While rolling without slipping, it moves rearward against the pressing force of the rubber spring by half the amount of relative axial movement between the recess 5 and the protrusion 6. When the protrusion 6 has been roughly inserted into the recess 5, the coupling pin 9 on the shank 1 side is screwed in, and the tapered tip 9a is press-fitted into the tapered hole 8 on the protrusion 6 side, thereby forming a wedge. The protrusion 6 is drawn into the recess 5 by the action, and the shank end face 10
and the end face 11 of the member to be coupled can be brought into pressure contact with each other.

It goes without saying that each of the spheres 17 and the inner circumferential surface 20 of the sphere and the outer circumferential surface 6a of the protrusion with which the spheres 17 come into contact with each other must have sufficient dimensional accuracy, roundness, and necessary hardness. be. Further, the tapered hole 8 and the coupling pin 9 can be arranged at two locations in the diametrical direction.

In the modified example shown in FIGS. 8 and 9, the bolt 14 for drawing the members to be joined is
is used to draw the protrusion 6 into the recess 5. In this case, since torque cannot be transmitted from the shank 1 to the member 7 to be coupled, a large diameter torque transmission sphere 21 is held in a part of the retainer 16 separately from the sphere 17, and this sphere 2
Grooves 22 and 23 into which the grooves are fitted are formed along the axial direction on the inner peripheral surface 20 of the sphere and the outer peripheral surface 6a of the protrusion. Therefore, when inserting the protrusion 6 into the recess 5, it is necessary to orient the torque transmitting sphere 21 so that it fits into the groove 22 on the recess 5 side.

Note that the torque transmitting sphere 21 only needs to be able to transmit torque from the shank 1 side to the coupled member 7 side, so when the two are coupled, the sphere 21
Both grooves 2 are in a state where they can move slightly between grooves 22 and 23.
2 and 23 so that the presence of the torque transmitting sphere 21 does not adversely affect the state of contact between the other sphere 17, the inner circumferential surface 20 of the sphere, and the outer circumferential surface 6a of the protruding portion. desirable.

In addition, when using the bolt 14 for drawing the members to be joined as in this modification, the protruding portion is used to make each sphere 17 enter the inside of the inner peripheral surface 20 of the sphere by utilizing the drawing action of the bolt 14. 6 can be forcefully and smoothly press-fitted into the recess 5.

The modified example shown in FIG. 10 is also configured so that the end face 10 on the shank side and the end face 11 on the side of the joined member 7 can be brought into pressure contact using the bolt 14 for drawing the joined members as described above. Although,
As a means for transmitting torque from the shank 1 side to the joined member 7 side, recesses 24 are formed at two locations in the diametrical direction of the shank side end face 10, and protrusions 25 that fit into the recesses 24 are inserted into the joined member side end face 11. It is attached with screws 26 at two locations in the diametrical direction. Therefore, when inserting the protrusion 6 into the recess 5, the protrusion 25
must be oriented so that it faces the recess 24.

(Operations and Effects of the Invention) As described above, according to the coupling device of the present invention, a plurality of circumferential spheres are disposed around the protrusion via a retainer, and a sphere on the concave side with which the group of spheres abuts. As long as sufficient dimensional accuracy, roundness, and necessary hardness are provided to the circumferential surface in contact with the body and the outer circumferential surface of the protrusion, each sphere can be attached to the circumferential surface of the sphere in the recess. By simply pressing the protrusion into the recess for inward penetration, the member to be joined will be held exactly concentric with the shank. By connecting the two using the connecting means in this state, the member to be joined can be rigidly connected to the shank in a concentric state and integrated, allowing high-precision machining work without the risk of so-called chatter or center runout. can be done. Moreover, as mentioned above, the parts that require sufficient dimensional accuracy are independent, and therefore manufacturing is relatively easy and practical.

Further, according to the configuration of the present invention, a plurality of circumferential spheres held by the retainer and in contact with the outer peripheral surface of the protrusion can be moved together with the retainer within a certain range in the axial direction of the protrusion. In addition, since a biasing means for biasing the group of spheres in the direction of the distal end of the protruding portion via the retainer is also provided, when the group of spheres enters the inner side of the circumferential surface of the sphere, Inside, each sphere can roll into contact with the inner circumferential surface of the sphere and the outer circumferential surface of the protrusion, and can move toward the base of the protrusion against the biasing force of the biasing means. In other words, since it can be rolled without slipping against the inner circumferential surface of each sphere or the outer circumferential surface of the protrusion, the fitting operation between the recess and the protrusion can be performed smoothly and easily with relatively little resistance. I can do it.

Moreover, the group of spheres is disposed around the base of the protrusion, and in the final stage of fitting and inserting the protrusion into the recess, the group of spheres bites into the circumferential surface of the sphere at the entrance of the recess. Therefore, the length of the ball group biting into and rolling against the inner peripheral surface of the sphere can be short, and the fitting operation between the recess and the protrusion can be easily performed.

Furthermore, since the periphery of the base of the protrusion and the entrance of the recess, which are closest to the contact point between the end face on the shank side and the end face on the side of the joined member, are centered by the group of spheres as described above, the two ends Even though centering is performed at one point in the axial direction, the joint member to be joined to the shank is more easily aligned with the shank than when centering is performed near the tip of the protruding portion away from the contact point of the surfaces. It is possible to center the whole thing reliably.

[Brief explanation of the drawing]

1 and 2 are schematic side views showing the state of connection of the joined member to the shank, and FIGS. 3 and 4 are
The figure is a longitudinal sectional side view of the main part showing the conventional example, Fig. 5 is a partial longitudinal sectional side view showing the embodiment of the present invention before joining, and Fig.
The figure is a partial vertical side view of the same connected state, and Figure 7 is the 6th
8 is a longitudinal sectional front view of the main part showing a modification, FIG. 9 is a longitudinal sectional front view of the same, and FIG. 10 is a partial longitudinal sectional side view showing another modification. 1...shank, 2...boring bite,
3... Tool head, 4... Extension attachment, 5... Cylindrical recess, 6... Cylindrical protrusion, 7
... Member to be joined, 8... Tapered hole, 9... Joining pin, 10, 11... End face, 14... Bolt for drawing member to be joined, 15... Screw hole, 16... Retainer, 17... Sphere. , 18...Snat spring, 19...Rubber spring, 20...Spherical inner peripheral surface, 21...Torque transmission sphere, 22, 23
... groove, 24 ... recess, 25 ... protrusion.

Claims (1)

[Scope of utility model registration request] A recess is provided concentrically on one of the shank and the member to be joined, and a protrusion that fits into the recess is provided concentrically on the other, and the end face on the shank side and the end face on the member to be joined are pressed together. The coupling device is provided with a coupling means that draws the protrusion inward to cause the protrusion to move, and is provided with a coupling means equipped with a torque transmission part from the shank to the coupled member, the coupling device having a retainer around the base of the protrusion. A plurality of spheres are arranged in the circumferential direction to be held and abut on the outer circumferential surface of the protrusion, and the group of spheres is configured to be movable within a certain range in the axial direction of the protrusion together with the retainer, and the retainer A biasing means for biasing the group of spheres in the direction of the distal end of the protrusion is provided at the entrance of the recess, and a diameter is constant in the axial direction with a diameter slightly smaller than the diameter of an imaginary circle circumscribing the group of spheres. A coupling device for connecting a shank with a tool head, etc., formed by forming a circumferential surface in a sphere.