JP7125748B2 - tip tool - Google Patents

Description

The present invention belongs to a technical field related to a tip tool attached to a rotary tool.

Conventionally, tip tools attached to rotary tools have been known.

In Patent Document 1, a connection shaft (shaft) that can be connected to a rotary tool, a socket portion that has a receiving port that can be fitted to a nut or the like, and a connection that connects the base end side of the socket portion and the connection shaft portion A tip tool is disclosed that has a member, a connecting member is formed of a metal cylindrical body, and a stopper ring for preventing falling is provided on the outer circumference of the connecting shaft portion inside the connecting member.

The connecting shaft portion of Patent Document 1 is provided with an annular concave portion for fitting a steel ball for a stopper that is connected and fixed with one touch when inserted into the mounting hole portion of the rotary tool.

JP 2012-143855 A

By the way, in the tip tool described in Patent Document 1, the portion of the shaft on the socket side of the annular recess (hereinafter referred to as the tip side portion) and the portion on the anti-socket side of the annular recess (hereinafter referred to as the base end portion). ) are inserted into the mounting holes.

As a result of extensive studies by the inventors of the present application, when the cross-sectional area of the distal side portion and the cross-sectional area of the proximal side portion are the same, the proximal side portion is more likely to contact the mounting hole than the distal side portion. It turns out that the area increases. When the proximal side portion has a larger contact area with the mounting hole than the distal side portion, the rotational force from the rotary tool is mainly input to the proximal side portion. Since there is a slight gap between the inner peripheral surface of the mounting hole and the base end side portion, when the shaft body is rotated by the rotary tool, slight blurring occurs. The blur generated at the base end side portion becomes larger as the distance from the base end side portion increases. As a result, the tip portion of the mounting hole is widened, and the opening of the mounting hole is generated.

When the opening occurs in the mounting hole, it becomes difficult to apply a rotational force from the rotary tool to the tip side portion. Therefore, when a nut or the like is tightened in a state where the mounting hole is open, a reaction force in the direction opposite to the rotational force is likely to be applied to the tip side portion from the nut or the like via the socket portion. Become. On the other hand, since the base end portion of the mounting hole is less deformed due to aging deterioration, the rotational force is applied to the base end side portion from the rotary tool. As a result, torsional stress is generated in the portion of the annular recess in the shaft, and the shaft may break at the portion of the annular recess.

SUMMARY OF THE INVENTION The present invention has been made in view of such a point, and an object thereof is to suppress breakage of the portion of the shaft that is inserted into the mounting hole of the rotary tool during fastening work. .

In order to solve the above-mentioned problems, the present invention is directed to a tip tool to be mounted on a rotary tool, and has a cylindrical socket and an insertion portion coupled to the socket and inserted into a mounting hole of the rotary tool. a shaft, wherein the mounting hole of the rotary tool is provided with a stopper for suppressing the insertion portion from slipping out of the mounting hole, and the insertion portion has an engaging portion that engages with the stopper. In the insertion portion, a portion on the socket side of the engaging portion is defined as a distal side portion, and a portion on the opposite side of the socket from the engaging portion is defined as a proximal side portion. The surface shape is similar to the cross-sectional shape of the mounting hole and is in contact with the inner peripheral surface of the mounting hole, and the cross-sectional area of the base end side portion is smaller than the cross-sectional area of the tip end side portion. It was configured.

According to this configuration, since the cross-sectional shape of the tip side portion is similar to the cross-sectional shape of the mounting hole and is in contact with the inner peripheral surface of the mounting hole, the torque of the rotary tool is appropriately applied to the tip side portion. is entered. Also, the cross-sectional area of the proximal side portion is smaller than the cross-sectional area of the distal side portion. As a result, the proximal side portion is less likely to come into contact with the inner circumferential surface of the mounting hole than the distal side portion. Therefore, the rotational force from the rotary tool is less likely to be applied to the proximal side portion, and the rotational force of the rotary tool is mainly transmitted to the distal side portion. As a result, even if the opening of the mounting hole occurs, the torsional stress applied to the engaging portion is reduced. For these reasons, it is possible to suppress breakage of the insertion portion during fastening work.

In one embodiment of the tip tool, the cross-sectional shape of the proximal side portion is circular.

According to this configuration, when the proximal side portion contacts the inner peripheral surface of the mounting hole, the proximal side portion is in point contact or line contact with the inner peripheral surface of the mounting hole. Therefore, the contact area between the base end portion and the inner peripheral surface of the mounting hole can be made as small as possible. This makes it possible to more effectively suppress breakage of the insertion portion during fastening work.

In another embodiment of the tip tool, the cross-sectional shape of the tip side portion is a polygonal shape, and the cross-sectional shape of the base end side portion is a polygonal shape with more corners than the tip side portion. .

According to this configuration, even if the base end side portion comes into contact with the inner peripheral surface of the mounting hole, the contact area can be made as small as possible. This makes it possible to more effectively suppress breakage of the insertion portion during fastening work.

In the tip tool, the shaft body has an overlapping portion that overlaps with the socket, and the overlapping portion is provided with a fragile portion that is thinner than the engaging portion of the insertion portion. may

According to this configuration, by breaking the fragile portion before the insertion portion is broken at the position of the engaging portion, it is possible to suppress torsional stress from being applied to the engaging portion. Thereby, breakage of the insertion portion can be suppressed more effectively.

As described above, according to the tip tool according to the present invention, the proximal side portion is less likely to come into contact with the inner peripheral surface of the mounting hole, and the rotational force from the rotary tool is less likely to be applied to the proximal side portion. As a result, since the rotational force of the rotary tool is transmitted mainly to the tip side portion, it is possible to suppress breakage of the insertion portion during fastening work.

FIG. 4 is a cross-sectional view showing the tip tool according to the embodiment of the present invention, showing a state in which it is attached to the attachment portion of the rotary tool. 2 is a sectional view corresponding to line II-II of FIG. 1; FIG. FIG. 2 is a sectional view corresponding to line III-III in FIG. 1; FIG. 5 is a cross-sectional view showing a tip tool according to a modified example of Embodiment 1; FIG. 8 is a cross-sectional view showing a tip tool according to Embodiment 2; 6 is a sectional view corresponding to line VI-VI of FIG. 5; FIG. FIG. 11 is a cross-sectional view showing a tip tool according to Embodiment 3;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

(Embodiment 1)
FIG. 1 shows a tip tool 1 according to the first embodiment. This tip tool 1 is a tool attached to a rotary tool 100 . Rotary tools 100 include manual and electric tools, such as ratchet handles and impact wrenches.

The tip tool 1 includes a cylindrical socket 2 and an elongated shaft 4 that is press-fitted into the socket 2 . As shown in FIG. 1, the shaft 4 extends from one end of the socket 2 in the axial direction toward one side in the axial direction. In Embodiment 1, the socket 2 is the part that acts on the bolt or nut, and the shaft 4 is the part that is attached to the rotary tool 100 . In the following description, the one side in the axial direction will be referred to as the base end side, and the other side in the axial direction will be referred to as the distal end side.

The socket 2 is formed in a substantially cylindrical shape, as shown in FIG. Specifically, the socket 2 includes a first cylindrical portion 21 having a relatively large outer diameter, and a diameter decreasing from the proximal end portion of the first cylindrical portion 21 in the axial direction toward the proximal end side in the axial direction. and a second cylindrical portion 23 extending from the base end portion of the diameter reduction portion 22 in the axial direction toward the base end side. The first cylindrical portion 21, the reduced diameter portion 22 and the second cylindrical portion 23 are coaxial. The socket 2 is made of metal.

Formed in the cylinder of the socket 2 are a press-fitted portion 31 into which the shaft 4 is press-fitted, and an action portion 24 that engages with a part (bolt or nut) rotated by the rotary tool 100 and acts on the part. It is The acting portion 24 has a shape that matches a bolt or nut, and has, for example, a hexagonal cross section.

A guide portion 32 having a smaller diameter than the press-fitted portion 31 is provided on the opposite side of the press-fitted portion 31 from the acting portion 24 in the cylinder of the socket 2 . This guide portion 32 is a portion for guiding the shaft 4 along the axial direction of the socket 2 when the shaft 4 is inserted into the socket 2 from the acting portion 24 side.

The diameter of the press-fitted portion 31 is shorter than the diagonal distance of the later-described joint portion 42 of the shaft 4 and longer than the face-to-face distance. Further, the diameter of the press-fitted portion 31 is larger than the diagonal distance of the shaft portion 41 of the shaft body 4 . The diameter of the guide portion 32 is slightly larger than the diagonal distance of the shaft portion 41 of the shaft body 4 .

The shaft 4 is made of metal having higher rigidity than the socket 2 . The shaft 4 includes a shaft portion 41 , a coupling portion 42 formed at one end of the shaft portion 41 and coupled to the socket 2 , and a coupling portion 42 formed at the other end of the shaft portion 41 and inserted into the mounting hole 101 of the rotary tool 100 . and an insertion portion 50 to be inserted. The connecting portion 42 has a hexagonal cross section. The cross-sectional area of coupling portion 42 is larger than the cross-sectional area of shaft portion 41 .

A portion of the shaft portion 41 on the base end side in the axial direction from the connecting portion 42 forms an overlapping portion 43 that radially overlaps with the socket 2 .

As shown in FIG. 1, the overlapping portion 43 includes a fragile portion 46 that is thinner than the other portion of the shaft 4 and a stepped portion 47 formed closer to the base end side than the fragile portion 46 in the axial direction. have The diameter of the stepped portion 47 is smaller than the diameter of the press-fitted portion 31 and larger than the diameter of the guide portion 32 . Since the fragile portion 46 is more fragile than other portions of the shaft body 4, when the shaft body 4 is broken when fastening a nut or the like using the tip tool 1, the fragile portion It is easy to break at the position of 46.

The insertion portion 50 of the shaft 4 has an engaging portion 51 that engages with a stopper 102 provided in the mounting hole 101 of the rotary tool 100 . The engaging portion 51 has an engaging groove 51a cut into an annular shape. The engaging portion 51 is thinner than other portions of the insertion portion 50 . The engaging portion 51 is thicker than the fragile portion.

A stopper 102 of the rotary tool 100 is a device for preventing the insertion portion 50 from coming off from the mounting hole 101 . The stopper 102 has a steel ball and a coil spring that biases the steel ball toward the central axis of the mounting hole 101 . When the insertion portion 50 is inserted into the mounting hole 101 , the steel ball moves toward the central axis of the mounting hole 101 by the biasing force of the coil spring and engages with the engaging groove 51 a of the engaging portion 51 . do. This prevents the insertion portion 50 from coming out of the mounting hole 101 .

In the first embodiment, the insertion portion 50 includes a portion closer to the socket 2 than the engaging portion 51 (the distal end side in the axial direction) (hereinafter referred to as a distal end portion 52 ) and a portion closer to the socket than the engaging portion 51 . 2 (the base end side in the axial direction) (hereinafter referred to as the base end portion 53) has a different shape.

As shown in FIG. 2 , the tip side portion 52 has a cross-sectional shape similar to the cross-sectional shape of the mounting hole 101 and in contact with the inner peripheral surface of the mounting hole 101 . Specifically, the mounting hole 101 has a hexagonal cross section, and the tip side portion 52 also has a hexagonal cross section. That is, the tip side portion 52 has a hexagonal prism shape. The cross-sectional area of the tip side portion 52 is slightly smaller than the cross-sectional area of the mounting hole 101 . As a result, when the insertion portion 50 is inserted into the mounting hole 101 , the surface of the tip side portion 52 is likely to come into surface contact with the inner peripheral surface of the mounting hole 101 . As a result, when the rotary tool 100 is driven, the rotational force of the rotary tool 100 is appropriately applied to the tip side portion 52 .

As shown in FIG. 3, the proximal side portion 53 has a circular cross-sectional shape. That is, the base end portion 53 is columnar. The diameter of the cross-sectional shape of the proximal side portion 53 is shorter than the distance between the mounting holes 101 facing each other. As shown in FIGS. 2 and 3 , the cross-sectional area of the proximal side portion 53 is larger than the minimum cross-sectional area of the engaging portion 51 and smaller than the cross-sectional area of the distal side portion 52 . As a result, when the insertion portion 50 is inserted into the mounting hole 101 and the surface of the proximal side portion 53 contacts the inner peripheral surface of the mounting hole 101 , the surface of the proximal side portion 53 is positioned inside the mounting hole 101 . Point contact or line contact with the peripheral surface. Therefore, when the rotary tool 100 is driven, the rotational force is less likely to be input to the base end portion 53 from the rotary tool 100 . The diameter of the cross-sectional shape of the proximal side portion 53 is not particularly limited as long as the cross-sectional area is larger than the minimum cross-sectional area of the engaging portion 51 and smaller than the cross-sectional area of the distal side portion 52 .

In the first embodiment, the tip tool 1 inserts the shaft 4 into the socket 2 from the working portion 24 side of the socket 2 so that the shaft portion 41 passes through the guide portion 32, and the coupling portion 42 is press-fitted. It is configured by being press-fitted and fixed to the portion 21 .

Here, as a result of intensive studies by the inventors of the present application, if the cross-sectional area of the distal side portion 52 and the cross-sectional area of the proximal side portion 53 are the same, the proximal side portion 53 is the distal side portion It was found that the contact area with the mounting hole 101 was larger than that of 52 . When the proximal side portion 53 has a larger contact area with the mounting hole 101 than the distal side portion 52 , the rotational force from the rotary tool 100 is mainly input to the proximal side portion 53 . In order to smoothly insert the insertion portion 50 , there is usually a slight gap between the inner peripheral surface of the mounting hole 100 and the base end portion 53 . Therefore, when the shaft body 4 is rotated by the rotary tool 100, a slight shake occurs. The blur generated in the proximal side portion 53 increases as the distance from the proximal side portion 53 increases. As a result, the tip portion of the mounting hole 101 is widened, and the opening of the mounting hole is generated.

When the tip portion of the mounting hole 101 of the rotary tool 100 is opened, the torque from the rotary tool 100 is less likely to be applied to the tip side portion 52 . Therefore, when a nut or the like is tightened in a state where the mounting hole 101 is open, a reaction force opposite to the rotational force is applied to the tip side portion 52 from the nut or the like via the socket 2 . It becomes easy to take. On the other hand, since the base end portion of the mounting hole 101 is less deformed due to deterioration over time, the rotational force from the rotary tool 100 is applied to the base end side portion 53 . As a result, torsional stress is generated in the engaging portion 51 of the shaft 4 , and the shaft 4 may break at the engaging portion 51 .

In contrast, in Embodiment 1, the cross-sectional shape of the distal side portion 52 is similar to the cross-sectional shape of the mounting hole 101 , while the cross-sectional area of the proximal side portion 53 is the same as that of the distal side portion 52 . smaller than area. As a result, the proximal side portion 53 is less likely to come into contact with the inner peripheral surface of the mounting hole 101 than the distal side portion 52 . Therefore, the rotational force from the rotary tool 100 is less likely to be applied to the base end portion 53 . Thereby, the rotational force of the rotary tool 100 is mainly transmitted to the tip side portion 53 . As a result, even if the opening of the mounting hole 101 occurs, the torsional stress applied to the engaging portion 51 is reduced. For these reasons, it is possible to suppress breakage of the insertion portion 50 during fastening work.

In particular, in Embodiment 1, the cross-sectional shape of the base end portion 52 is circular. Accordingly, even if the proximal side portion 53 contacts the inner peripheral surface of the mounting hole 101 , the proximal side portion 53 makes point contact or line contact with the inner peripheral surface of the mounting hole 101 . Therefore, the contact area between the base end portion 52 and the inner peripheral surface of the mounting hole 101 can be made as small as possible. As a result, the rotational force from the rotary tool 100 is less likely to be applied to the base end portion 53 . As a result, it is possible to more effectively suppress breakage of the insertion portion 50 during fastening work.

Further, in Embodiment 1, the overlapping portion 43 of the shaft 4 is provided with the weakened portion 46 . As a result, before the insertion portion 50 is broken, the shaft body 4 is broken at the fragile portion 46 to suppress the generation of torsional stress in the engaging portion 51, thereby making the breakage of the insertion portion 50 more effective. can be suppressed to

Further, when the shaft 4 is broken at the fragile portion 46, the shaft 4 tries to come off from the socket 2, but the stepped portion 47 is caught on the guide portion 32, so that the shaft 4 does not come off from the socket 2. - 特許庁Thereby, it is possible to prevent the socket 2 from falling when the shaft 4 is broken.

FIG. 4 shows a modification of the first embodiment. In this modification, the shaft 104 does not have the weakened portion 46 and the stepped portion 47 . Even with this configuration, the cross-sectional shape of the distal side portion 52 is similar to the cross-sectional shape of the mounting hole 101, and the cross-sectional area of the proximal side portion 53 is smaller than the cross-sectional area of the distal side portion 52. Breakage of the insertion portion 50 during fastening work can be suppressed.

(Embodiment 2)
Hereinafter, Embodiment 2 will be described in detail with reference to the drawings. In the following description, parts common to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, the cross-sectional shape of the base end portion 253 of the shaft 204 is different from that of the first embodiment. More specifically, as shown in FIGS. 5 and 6, the cross-sectional shape of the proximal side portion 253 is a polygonal shape having more corners than the distal side portion 52 . More specifically, the cross-sectional shape of the proximal side portion 253 is a dodecagon. That is, in the second embodiment, the base end portion 253 has a dodecagonal prism shape. Further, in the second embodiment, the shaft 204 does not have the fragile portion 46 and the stepped portion 47 as in the modified example of the first embodiment. The cross-sectional shape of the proximal side portion 253 does not have to be a regular dodecagon, and adjacent corners may have different internal angles.

The contact area can be made as small as possible also in the configuration of the second embodiment. Therefore, even with the configuration of the second embodiment, breakage of the insertion portion 250 during fastening work can be suppressed.

(Embodiment 3)
Hereinafter, Embodiment 3 will be described in detail with reference to the drawings. In the following description, parts common to those of the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the third embodiment, the configuration of the engaging portion 351 in the shaft 304 is different from that in the first and second embodiments. The proximal side portion 53 has the same configuration as that of the first embodiment. Further, in the third embodiment, the shaft 304 does not have the fragile portion 46 and the stepped portion 47 as in the modified example of the first embodiment.

In the third embodiment, as shown in FIG. 7, the engaging portion 351 has six spherical engaging concave portions 351a. The six engaging recesses 351a are formed on the sides of the hexagon. When the insertion portion 350 is inserted into the mounting hole 101, the steel ball 102b of the stopper 102 engages with the engaging recess 351a.

In Embodiment 3, the minimum value of the cross-sectional area of the engaging portion 351 can be made as large as possible compared to the case where the engaging groove is provided. Therefore, the rigidity of the engaging portion 351 can be increased compared to the case where the engaging groove is provided. Thereby, breakage of the insertion portion 350 can be suppressed more effectively.

(Other embodiments)
The present invention is not limited to the above embodiments, and substitutions are possible without departing from the scope of the claims.

For example, in Embodiments 1 to 3 described above, the shafts 4, 204, and 304 are inserted from the acting portion 24 side of the socket 2, and the connecting portion 42 is press-fitted into the press-fitted portion 31. As shown in FIG. However, if the shaft is not provided with a fragile portion and a stepped portion, the coupling portion 42 of the shaft 4, 204, 304 is located on the opposite side of the socket 2 to the acting portion 24 (in the axial direction). It may be press-fitted into the press-fitting portion 31 from the base end side). In this case, the socket 2 does not need to be provided with the guide portion 32, and the press-fitted portion 31 may extend to the proximal end of the socket 2 in the axial direction.

Further, the engaging portion 51 of the second embodiment may be shaped like the engaging portion 351 of the third embodiment.

Further, the shaft 204 of the second embodiment may be provided with the fragile portion 46 and the stepped portion 47 as in the first embodiment. In this case, as described above, the shaft 204 is inserted from the acting portion 24 side of the socket 2 and the connecting portion 42 is press-fitted into the press-fitted portion 31 .

The above-described embodiments are merely examples, and should not be construed as limiting the scope of the present invention. The scope of the present invention is defined by the scope of claims, and all variations and modifications within the equivalent scope of the claims are within the scope of the invention.

INDUSTRIAL APPLICABILITY The present invention is useful as a tip tool attached to a rotary tool.

1 Tip Tool 2 Socket 4, 204, 304 Shaft 50, 250, 350 Insertion Portion 51, 351 Engagement Portion 52 Tip Side Portion 53, 253 Base End Side Portion 100 Rotary Tool 101 Mounting Hole 102 Stopper

Claims (4)

A tip tool attached to a rotary tool,
cylindrical socket,
a shaft having an insertion portion coupled to the socket and inserted into the mounting hole of the rotary tool;
The mounting hole of the rotary tool is provided with a stopper for preventing the insertion portion from coming out of the mounting hole,
The insertion portion has an engaging portion that engages with the stopper,
In the insertion portion, a portion closer to the socket than the engaging portion is defined as a distal side portion, and a portion closer to the socket than the engaging portion is defined as a proximal side portion,
The cross-sectional shape of the tip side portion is similar to the cross-sectional shape of the mounting hole and is in contact with the inner peripheral surface of the mounting hole,
The tip tool, wherein the cross-sectional area of the base end side portion is smaller than the cross-sectional area of the tip side portion. The tip tool according to claim 1,
The tip tool, wherein the cross-sectional shape of the base end portion is circular. The tip tool according to claim 1,
The cross-sectional shape of the tip side portion is polygonal,
The tip tool is characterized in that the cross-sectional shape of the base end side portion is a polygonal shape with more corners than the tip side portion. In the tip tool according to any one of claims 1 to 3,
The shaft has an overlapping portion that overlaps with the socket,
The tip tool, wherein the overlapping portion is provided with a fragile portion that is thinner than the engaging portion of the insertion portion.

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