WO2023047568A1 - Positioning structure, spring pin, and positioning member - Google Patents

Abstract

A positioning structure (1) is provided with: a first hole (41H) provided to a first member (40); a second hole (10H) provided to a second member (10); a spring pin (50) fitted to both the first hole (41H) and the second hole (10H) in a state where the first hole (41H) and the second hole (10H) are coaxially arranged; and a reception-side screw part (61) that is disposed in the spring pin (50) or in the first hole (41H) in a state in which the spring pin (50) is fitted therein and that is capable of fastening a jig-side screw part of a shaft-like jig inserted, along the axis (M) of the first hole (41H), in the spring pin (50) fitted in the first hole (41H). The reception-side screw part (61) transmits force to the spring pin (50) in the direction of the axis (M) applied to the jig in a state where the jig-side screw part is fastened, and restricts rotation about the axis (M) during fastening of at least the jig-side screw part.

Description

Positioning structure, spring pin and positioning member

The present disclosure relates to positioning structures, spring pins and positioning members.

In a mechanical device such as a robot, as a positioning structure for fixing two members in a positioned state, a structure having pin holes provided in the two members and spring pins inserted into both pin holes is known ( For example, see Patent Document 1.).
Since the outer surface of the spring pin is brought into close contact with the inner surface of the pin hole by the spring force, it is generally difficult to pull out the spring pin from the pin hole, such as disassembling the mechanical device.

In Patent Document 1, a nut is attached to the tip of a bolt that is inserted into a spring pin from one end side and protruded from the other end side, and a force is applied to the bolt to pull it out from the one end side, so that the nut is moved to the other end side of the spring pin. , and a pull-out force is applied to the spring pin.

Japanese Utility Model Laid-Open No. 01-016281

However, if the pin hole into which the spring pin is inserted does not pass through, or if it passes through but is narrow enough to make it difficult to support the nut by hand, the method of Patent Document 1 can be used. Can not. Therefore, even if the pin hole does not penetrate or is narrow even if it penetrates, it is desired to reliably position the two members while facilitating the pulling out of the spring pin.

In one aspect of the present disclosure, in a state in which a first hole provided in a first member, a second hole provided in a second member, and the first hole and the second hole are coaxially arranged, the a spring pin that is commonly fitted in the first hole and the second hole; and a spring pin that is disposed in the spring pin or in the first hole in which the spring pin is fitted, and is fitted in the first hole. a receiving-side threaded portion capable of fastening a jig-side threaded portion of a shaft-shaped jig inserted along the axis of the first hole in the spring pin, wherein the receiving-side threaded portion The force in the axial direction applied to the jig in a state where the jig-side threaded portion is fastened is transmitted to the spring pin, and rotation about the axis is restricted at least when the jig-side threaded portion is fastened. Positioning structure.

1 is a partial longitudinal cross-sectional view of a single axis positioner with positioning structure according to an embodiment of the present disclosure; FIG. 2 is an enlarged longitudinal sectional view of the positioning structure of FIG. 1; FIG. FIG. 2 is a perspective view showing a spring pin in the positioning structure of FIG. 1; FIG. 4 is a diagram showing a method of pulling out a spring pin from a pin hole in the positioning structure of FIG. 1; FIG. 2 is a schematic diagram showing a modification of pin holes in the positioning structure of FIG. 1; FIG. 3 is a longitudinal sectional view showing a modification of the spring pin in the positioning structure of FIG. 1;

A positioning structure 1 according to an embodiment of the present disclosure will be described below with reference to the drawings.
The positioning structure 1 according to this embodiment is provided in, for example, a single-axis positioner 100 as shown in FIG. However, the mechanical device to which the positioning structure 1 is applied is not limited to the single-axis positioner 100, and can be applied to arbitrary mechanical devices such as robots and machine tools.

A single-axis positioner 100 includes a base (second member) 10 installed on a horizontal floor surface, and a table 20 rotatably supported by the base 10 around a horizontal rotation axis L. The single-axis positioner 100 also includes a servomotor 30 fixed to the base 10 and a speed reducer (first member) 40 that reduces the speed of rotation of a shaft (not shown) of the servomotor 30 and transmits the speed to the table 20 . ing.

The speed reducer 40 includes an output shaft portion 41 fixed to the base 10 and a movable portion 43 that rotates around the rotation axis L at a reduced rotational speed with respect to the output shaft portion 41 . The table 20 is fixed to the movable portion 43 .
The base 10 includes a concave fitting portion 11 for fitting the output shaft portion 41 of the speed reducer 40, a plurality of through holes 10h extending parallel to the rotation axis L and spaced in the circumferential direction, and and a pin hole (second hole) 10H extending parallel to it.

The speed reducer 40 corresponds to a plurality of screw holes 41t provided at positions corresponding to the through holes 10h and the pin holes 10H of the base 10 when the output shaft portion 41 is fitted to the spigot portion 11 of the base 10. and a pin hole (first hole) 41H provided at a position where

As shown in FIGS. 1 and 2, the positioning structure 1 according to the present embodiment includes a pin hole 10H provided in the base 10, a pin hole 41H provided in the output shaft portion 41, and both pin holes 10H and 41H. and a nut 60 arranged in the pin hole 41H.

The pin hole 41H is a non-through hole formed from the end surface of the output shaft portion 41 to a predetermined depth parallel to the rotation axis L, and has a bottom surface 41B. The axis M, which is the central axis of the pin hole 41H, is parallel to and eccentric to the rotation axis L, and is arranged at a different position from the screw hole 41t.

The pin hole 10H is a through hole that extends parallel to the rotation axis L at an eccentric position, and has the same inner diameter as the pin hole 41H. The pin hole 10H coincides with the pin hole 41H when the output shaft portion 41 is fitted into the spigot portion 11 and arranged at relative angular positions around the rotation axis L where all the screw holes 41t and the through hole 10h coincide. placed in position.

For example, as shown in FIG. 3, the spring pin 50 is formed by bending a thin plate made of metal such as spring steel so as to form a gap S of a constant width extending in the longitudinal direction, thereby forming a cross-sectional shape. is formed in a substantially C-shaped tubular shape. The outer diameter dimension of the spring pin 50 in a free state where no external force is applied is set slightly larger than the inner diameter of the pin holes 10H and 41H. Further, the spring pin 50 can be reduced in outer diameter by the width of the gap S, and can be fitted into the pin holes 10H and 41H while being deformed so as to reduce the outer diameter.
By fitting the spring pin 50 across both the pin holes 10H and 41H along the axis M, the base 10 and the output shaft portion 41 are positioned at a predetermined relative angle around the rotation axis L.

The nut 60 has an outer shape slightly smaller than the inner diameter of the pin hole 41H and larger than the inner diameter of the spring pin 50, as shown in FIG. The nut 60 has a female thread (receiving side threaded portion) 61, and the female thread 61 has a root diameter smaller than the inner diameter of the spring pin 50 fitted in the pin holes 10H and 41H. As the nut 60, a commercially available hexagonal nut may be used, or a tubular member such as a cylinder having an internal thread 61 formed on the inner surface thereof may be used.

In the positioning structure 1 according to the present embodiment, the nut 60 is arranged on the bottom surface 41B of the pin hole 41H with the central axis of the female screw 61 directed in the direction along the axis M, and the spring pin 50 is driven into the pin hole 41H. It is arranged in a state sandwiched between one end and the bottom surface 41B. As a result, the nut 60 is arranged in a state where rotation about the axis M is restricted by friction generated between one end of the spring pin 50 and the bottom surface 41B of the pin hole 41H.

The operation of the positioning structure 1 according to this embodiment configured in this manner will be described below.

In the example shown in FIG. 1 , to assemble the speed reducer 40 to the base 10 , the output shaft portion 41 of the speed reducer 40 is fitted into the spigot portion 11 of the base 10 . Then, the relative angular position of the output shaft portion 41 around the rotation axis L with respect to the spigot portion 11 is adjusted so that the pin holes 10H and 41H are substantially coaxial. In this state, the nut 60 is inserted into the pin holes 10H and 41H and pushed until it reaches the bottom surface 41B. At this time, the posture of the nut 60 is such that the central axis of the internal thread 61 is aligned with the axis M. As shown in FIG. Since the outer shape of the nut 60 is slightly smaller than the cross-sectional shape of the pin hole 41H, the posture in the pin hole 41H can be maintained as it is if the posture is adjusted at the time of insertion.

Then, as shown in FIG. 2, the spring pin 50 is driven into the pin holes 10H and 41H from the outside of the pin hole 10H along the axis M, and the tip of the spring pin 50 presses the nut 60 against the bottom surface 41B. In this state, the bolts 15 are passed through the plurality of through holes 10 h provided in the base 10 and fastened to the screw holes 41 t of the output shaft portion 41 . As a result, the base 10 and the output shaft portion 41 can be fixed at a predetermined relative angle around the rotation axis L in a precisely positioned state.

Further, when separating the base 10 and the speed reducer 40 in work such as maintenance of the single-axis positioner 100, it is necessary to remove the spring pin 50 from the pin holes 10H and 41H. In such a case, for example, as shown in FIG. 4, a bolt (jig) 70 having a male thread (jig-side threaded portion) 71 that can be fastened to a female thread 61 of a nut 60 is inserted into the pin hole 10H. , 41H from the outside along the axis M. As shown in FIG.
Then, the male thread 71 at the tip of the bolt 70 is fastened to the female thread 61 of the nut 60 arranged at the tip of the spring pin 50 .

In this case, since the nut 60 is sandwiched between the tip of the spring pin 50 and the bottom surface 41B, a static frictional force is generated between the nut 60 and the tip of the spring pin 50 and the bottom surface 41B. This frictional force restricts the rotation of the nut 60 about the axis M, and even if the rotational force about the axis M applied to the bolt 70 when fastening the male screw 71 to the female screw 61 is transmitted to the nut 60, the rotational force This prevents the nut 60 from rotating around the axis M. Therefore, the male thread 71 of the bolt 70 can be easily and sufficiently fastened to the female thread 61 of the nut 60 .

Next, when a force is applied to the bolt 70 along the axis M in a direction to pull it out from the spring pin 50, the force is transmitted to the spring pin 50 via the nut 60 fastened to the tip of the bolt 70. be done. As a result, the spring pin 50 is moved along the axis M together with the bolt 70 and the nut 60, and pulled out of the pin holes 10H and 41H.

Thus, according to the positioning structure 1 according to the present embodiment, the operator can fix the nut 60 to the tip of the bolt 70 passing through the spring pin 50 without pressing the nut 60 .
That is, even if the pin hole 41H does not pass through, the spring pin 50 can be easily removed using the bolt 70 inserted from the pin hole 10H side.

Note that in the present embodiment, the tip of the spring pin 50 presses the nut 60 against the bottom surface 41B of the pin hole 41H, thereby restricting the rotation of the nut 60 around the axis M. In this case, at least one of the tip surface of the spring pin 50, the end surface of the nut 60, and the bottom surface 41B of the pin hole 41H is treated to increase friction, such as increasing the surface roughness or providing unevenness that meshes in the direction of the axis M. You may set it.

Alternatively, the rotation of the nut 60 around the axis M may be restricted by directly fixing the nut 60 to the tip of the spring pin 50 .
For example, the nut 60 may be coaxially arranged on one end of the spring pin 50, and both may be fixed by adhesion or welding. In this case, the nut 60 is preferably bonded or welded to a region that does not hinder the radial deformation of the spring pin 50, such as region F shown in FIG. As a result, the nut 60 can be maintained attached to the spring pin 50 even if the outer diameter of the spring pin 50 shrinks by driving the spring pin 50 into the pin holes 10H and 41H.
By driving the spring pin 50 into the pin holes 10H and 41H with the nut 60 at the top, the base 10 and the output shaft portion 41 can be positioned.

On the other hand, when removing the spring pin 50 from the pin holes 10H and 41H, the male thread 71 of the bolt 70 inserted into the spring pin 50 from the outside is fastened to the female thread 61 of the nut 60 in the same manner as described above. At the time of fastening, the rotational force applied to the bolt 70 is transmitted to the nut 60, but the nut 60 is fixed to the spring pin 50 and therefore remains stationary.

In addition, since the outer peripheral surface of the spring pin 50 is in close contact with the inner peripheral surfaces of the pin holes 10H and 41H due to the spring force, the rotational force transmitted from the bolt 70 to the nut 60 also rotates within the pin holes 10H and 41H. It remains stationary without
As a result, the operator can easily and sufficiently fasten the nut 60 to the tip of the bolt 70 without pressing the nut 60 . Further, unlike the above-described embodiment, the nut 60 does not need to be held by the bottom surface 41B of the pin hole 41H. It can also be applied when

In addition, when assembling the base 10 and the speed reducer 40, it is possible to omit the work of inserting the nut 60 into the pin hole 41H in advance, which is advantageous in that workability can be improved.
Moreover, regardless of the shape of the bottom surface 41B of the pin hole 41H, the nut 60 can be maintained in a posture that allows the bolt 70 to be easily tightened. Furthermore, since it is not necessary to sandwich the nut 60 between the tip of the spring pin 50 and the bottom surface 41B of the pin hole 41H, the spring pin 50 does not have to be driven until the nut 60 is pressed against the bottom surface 41B. Therefore, there is an advantage that the depth of the pin hole 41H need not be strictly controlled.

Further, instead of gluing or welding the nut 60 to the spring pin 50, the nut 60 and the bottom surface 41B of the pin hole 41H are temporarily fixed with an adhesive force that separates them when a torque of a predetermined value or more is input. may
In this case, before inserting the nut 60 into the pin hole 41H, the bottom surface 41B or the part of the nut 60 that comes into contact with the bottom surface 41B may be coated with a predetermined amount of adhesive previously determined by experiments or the like.

That is, if the rotational force transmitted from the bolt 70 is equal to or less than a predetermined torque, the nut 60 is maintained in a temporarily fixed state, so the nut 60 can be fastened to the tip of the bolt 70 without pressing the nut 60. can be done. After tightening, the nut 60 can be separated from the bottom surface 41B by applying a predetermined torque or more to the bolt 70 .
As a result, the pull-out force applied to the bolt 70 can be applied to the spring pin 50 via the nut 60, so that the spring pin 50 can be easily pulled out.

Further, a stopper that contacts the outer surface (peripheral surface) 60a of the nut 60 to restrict the rotation of the nut 60 around the axis M may be provided on the bottom surface 41B of the pin hole 41H.
For example, as shown in FIG. 5 , if the nut 60 is a commercially available hexagonal nut, the nut 60 may be fitted into the bottom surface 41B of the pin hole 41H in a hexagonal hole shape, or at least a hole facing the nut 60. A concave portion 42 having an inner surface (contact surface) 42a that is brought close to a position sandwiching the two surfaces may be provided.

In this case, by fitting the nut 60 into the recess 42 , even if the torque of the bolt 70 is transmitted to the nut 60 , the rotation of the nut 60 about the axis M is restricted.
Therefore, similarly to the above, the nut 60 can be easily fastened to the tip of the bolt 70 without pressing the nut 60 . After the bolt 70 is tightened, when a pull-out force is applied to the bolt 70 , the nut 60 is released from the recess 42 , and the pull-out force can be applied to the spring pin 50 .

In addition, in this embodiment, the bolt 70 is used as the shaft-shaped jig, and the internal thread 61 of the nut 60 is used as the receiving-side threaded portion. Instead of this, a jig having a threaded hole (jig-side threaded portion) formed in the longitudinal direction from the front end surface of the columnar jig main body is adopted as the shaft-shaped jig, and the nut 60 is replaced by , a bolt having a male thread (receiving side threaded portion) may be inserted into the pin hole 41H.

Also, in the present embodiment, the case where the spring pin 50 that is fitted in both the pin hole 10H and the pin hole 41H is pulled out has been described as an example, but the present invention is not limited to this. For example, it can be applied to pull out the spring pin 50 remaining in the pin hole 41</b>H of the output shaft portion 41 that has been removed from the base 10 .

Next, a spring pin 80 according to an embodiment of the present disclosure will be described below with reference to the drawings.
As shown in FIG. 6, the spring pin 80 according to this embodiment has a female thread (receiving side threaded portion) 81 formed on the inner surface of the known spring pin 50 used in the positioning structure 1 according to one embodiment described above. It is what I did.

The female thread 81 is formed over a predetermined length range only on one end side of the spring pin 80 in the longitudinal axis direction. The internal thread 81 is shaped to properly mesh with the bolt 70 inserted into the spring pin 80 when the spring pin 80 is shrunk to a size that fits in the pin hole. That is, when the bolt 70 has, for example, an M6 male thread of metric coarse thread, the female thread 81 is formed into a shape of an M6 female thread of metric coarse thread in the shape in which the spring pin 80 is contracted. .

When two members are positioned by using the spring pin 80 configured in this way, the pair of pin holes provided in each member are arranged in a row, and the spring pin 80 is formed with a female thread 81. Drive into the pin hole from the side end.

On the other hand, to pull out the spring pin 80 from the pin hole, insert the bolt 70 into the spring pin 80 along the central axis of the pin hole. A male thread 71 provided at the tip of the bolt 70 is then fastened to a female thread 81 provided on the inner surface of the spring pin 80 .

In this case, since the spring pin 80 is in close contact with the inner peripheral surface of the pin hole and is stationary, the operator can fasten the bolt 70 to the female screw 81 simply by rotating it around its axis. By applying a pull-out force to the bolt 70, the pull-out force is applied directly to the spring pin 80, so that it can be pulled out easily and reliably from the pin hole.

According to the spring pin 80 according to this embodiment configured in this way, the nut 60 in the positioning structure 1 according to one embodiment can be omitted, so there is an advantage that the number of parts can be reduced.
In addition, the female thread 81 is provided only on one end side in the longitudinal direction, and the bolt 70 inserted into the spring pin 80 can be pulled out by driving the spring pin 80 in the direction in which the female thread 81 is arranged on the inner side of the pin hole. can be fastened to the internal thread 81 on the far side of the pin hole.

As a result, even if the diameter of the front side portion of the spring pin 80 that is first extracted from the pin hole is partially expanded during the operation of pulling out the spring pin 80, the spring pin 80 that is fitted in the pin hole can still be pulled out. The side portions are maintained in a contracted state. Therefore, the meshing between the female screw 81 formed in the inner part and the bolt 70 is maintained in a proper meshing state until the spring pin 80 is sufficiently pulled out, and the meshing can be prevented from being disengaged during pulling out.

In this embodiment, the female thread 81 is provided only at one end of the spring pin 80 in the longitudinal direction. Alternatively, they may be provided at both ends with an interval in the longitudinal direction. The female threads 81 formed on both ends with a gap in the longitudinal direction must be arranged in a phase that allows the male threads 71 of the bolt 70 inserted from one end of the spring pin 80 to be simultaneously fastened.

With this configuration, there is an advantage that the spring pin 80 can be driven into the pin hole without worrying about the direction of the pin. On the other hand, in order to obtain the above effect, it is necessary to fasten the bolt 70 to the internal thread 81 on the far side of the spring pin 80 fitted in the pin hole.
In addition, by providing the female threads 81 over the entire length of the spring pin 80 or at both ends with a gap in the longitudinal direction, the length of the bolt 70 that can be fastened to the male threads 71 can be made sufficiently long. There are advantages.

1 positioning structure 10 base (second member)
10H pin hole (second hole)
40 reducer (first member)
41H pin hole (first hole)
41B bottom surface 42a inner surface (contact surface)
50 spring pin 60 nut 60a outer surface (peripheral surface)
61 internal thread (receiving side thread)
70 bolt (jig)
71 male screw (jig side screw)
80 Spring pin 81 Female screw (receiving side screw part)
M axis

Claims (15)

a first hole provided in the first member;
a second hole provided in the second member;
a spring pin commonly fitted into the first hole and the second hole in a state in which the first hole and the second hole are arranged coaxially;
It is arranged in the spring pin or in the first hole in which the spring pin is fitted, and is inserted into the spring pin fitted in the first hole along the axis of the first hole. a receiving-side threaded portion capable of fastening a jig-side threaded portion of a shaft-shaped jig,
The receiving-side threaded portion transmits to the spring pin the axial force applied to the jig in a state where the jig-side threaded portion is fastened, and at least when the jig-side threaded portion is fastened, A positioning structure in which rotation about the axis is restricted. The jig-side threaded portion is a male screw provided at the tip of the jig,
The positioning structure according to claim 1, wherein the receiving side threaded portion is a female thread. the first hole has a bottom surface,
3. The positioning structure according to claim 2, wherein the receiving side threaded portion is provided in a nut arranged between the spring pin fitted in the first hole and the bottom surface. The positioning structure according to claim 3, wherein the nut is sandwiched between the bottom surface and the spring pin in the axial direction, thereby restricting rotation about the axis. The positioning structure according to claim 3 or claim 4, wherein the bottom surface is treated to increase friction with the nut. The positioning structure according to claim 3, wherein the nut is fixed to the spring pin. The positioning structure according to claim 3, wherein the nut is separably fixed to the bottom surface by a torque of a predetermined level or more. the nut having an outer peripheral surface with a non-circular cross-sectional shape;
4. The positioning structure according to claim 3, wherein the first hole has a contact surface that restricts rotation of the nut about the axis by contacting the outer peripheral surface of the nut. The positioning structure according to claim 2, wherein the receiving side threaded portion is formed on at least a part of the inner peripheral surface of the spring pin in the longitudinal direction. The positioning structure according to claim 9, wherein the receiving side threaded portion is provided at the end portion in the longitudinal axis direction. The positioning structure according to claim 10, wherein the receiving-side screw portions are provided at both ends in the longitudinal axis direction. A spring pin having an internal thread extending along at least a portion of its longitudinal axis on its inner surface. 13. The spring pin according to claim 12, wherein the internal thread is provided at the longitudinal end. The spring pin according to claim 13, wherein the female threads are provided at both ends in the longitudinal direction. spring pin and
A locating member comprising a nut fixed to one end of the spring pin.

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