JP2711948B2 - Fixed structure such as shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a shaft or the like applied to a structure for mounting a blade of a tool, for example.

[0002]

2. Description of the Related Art A plurality of types of blades having different diameters and the like are removably attached to tools such as drills, milling machines and tapping machines. Conventionally, a so-called chuck using a screw fastening mechanism has been used as a structure for attaching a blade to the rotating portion of these tools.

[0003]

However, in the mounting structure using the chuck described above, when a blade is mounted on a rotating portion and a work is performed, a load fluctuation due to rotational force is likely to occur due to contact with a workpiece, and a sudden load fluctuation occurs. As a result, the screw is loosened, the fastening force of the chuck is reduced, and slippage occurs between the chuck and the blade, resulting in uneven rotation. For this reason, proper processing may not be performed.

[0004] In addition, since the work of replacing the blade requires loosening the chuck, replacing the blade, and retightening the chuck, there is a problem that the replacement requires a lot of time and labor. Furthermore, in order to firmly fix the blade, it is necessary to tighten the blade with a higher force in consideration of cutting resistance, and an appropriate grip force and skill are required.

Accordingly, an object of the present invention is to provide a fixing structure of a shaft or the like which can easily attach a shaft such as a blade of a tool and which does not become loose even when a strong load is applied to the rotational force. Is to do.

[0006]

In order to achieve the above object, the present invention relates to a fixing structure for a shaft or the like for fixing an end of a shaft or the like by inserting the end of the shaft into the inner periphery of the receiving member. At least two one-way clutches having different engagement directions are mounted on the inner periphery of the one-way clutch, the shafts and the like are inserted, and a retaining mechanism for preventing the shafts and the like from coming off the receiving member in the axial direction is provided. It is characterized by having.

In a preferred aspect of the present invention, the retaining mechanism is elastically pressed against a concave portion formed on an outer periphery of the shaft or the like, and protrudes from an inner periphery of the receiving member to an outer periphery of the shaft or the like. And an engaging member.

[0008] In a further preferred aspect of the present invention, the shaft or the like is a blade of a tool, and the receiving member is a chuck portion of the tool.

[0009]

According to the present invention, at least two one-way clutches having different meshing directions are mounted on the inner periphery of the receiving member, and when a shaft or the like is inserted into the inner periphery of the one-way clutch, the one-way clutch for the shaft or the like receives the one-way clutch. Rotation in one direction is prevented by the one-way clutch engaged in that direction, and rotation in the other direction is also prevented by the one-way clutch engaged in the opposite direction. Further, the shaft and the like are prevented from falling off by the retaining mechanism with respect to the receiving member.

[0010] Therefore, the shaft and the like, with respect to the receiving member,
It is stopped and stopped and fixed. The one-way clutch detent function does not loosen like a screw even when the load fluctuates with respect to the rotational force, so the shaft and the like can be firmly held even when a load fluctuating during the rotation operation is applied. . In addition, when attaching the shaft to the receiving member, it is only necessary to insert the shaft etc. into the receiving member and fix it with the retaining mechanism, and it is not necessary to tighten the screw with a strong gripping force. Can be performed quickly and easily.

In a preferred aspect of the present invention, the retaining mechanism is provided with a concave portion formed on an outer periphery of the shaft and the like, and a projection protruding from an inner periphery of the receiving member and elastically pressed against an outer periphery of the shaft and the like. In the case of the joint member, when the shaft or the like is inserted into the receiving member, the engaging member is elastically engaged with the concave portion formed on the outer periphery of the shaft or the like to prevent the shaft from coming off. Further, by strongly pulling the shaft or the like, the engaging member retracts outward and comes off the concave portion, so that the shaft or the like can be removed. Therefore, the work of attaching and detaching the shaft and the like becomes extremely easy.

In a preferred aspect of the present invention, when the shaft or the like is a blade of a tool and the receiving member is a chuck portion of the tool, when performing various types of machining by rotating the blade of the tool, For the reasons described above, the shaft or the like can be firmly held even when a fluctuating load is applied, and the blade can be prevented from coming off due to loose holding force. Further, for the above-mentioned reason, the replacement work of the tool blade becomes quick and easy, so that the workability can be improved.

In the present invention, a so-called roller type one-way clutch is preferably employed as the one-way clutch. Further, in the present invention, the axis etc.
It is not limited to the blade of the tool, but includes a cylindrical body and a cylindrical body used for various mechanical parts.

[0014]

1 to 3 show an embodiment in which the present invention is applied to a fixing structure of a tool blade. 1 shows a structure for fixing a blade of a tool, FIG. 2 shows a structure of a ball plunger used for a retaining mechanism of the fixed structure, and FIG.
Shows the structure of the one-way clutch having the fixed structure.

In FIG. 1, an arbor 11 is connected to a rotating part of a machine tool (not shown) and is rotated by a drive mechanism of the machine tool. The tip 12 of the arbor 11 has a tapered shape, and is press-fitted into a tapered opening 15 of a hole 14 of a cylindrical holder 13, thereby substantially forming the cylindrical holder 1.
3 is integrated. The portion of the hole 14 on the side opposite to the opening 15 is an inner circumference 16 having an enlarged diameter.
6, two one-way clutches 1 with opposite meshing directions
7, 18 are press-fitted along the axial direction. Note that the cylindrical holder 13 corresponds to a chuck portion in a conventional tool.

A base end of an end mill 19, which is a tool blade, is inserted into the inner periphery of the one-way clutches 17 and 18 from a direction opposite to the opening 15 of the cylindrical holder 13. A plurality of, for example, three hemispherical concave portions 20 are formed on the outer periphery of the base end portion of the end mill 19. In this regard, a plurality of holes 21 extending at right angles to the axial direction are formed in the cylindrical holder 13 at positions corresponding to the recesses 20 when the base end of the end mill 19 is inserted,
A ball plunger 22 is press-fitted into these holes 21. The recess 20 and the ball plunger 22 form a retaining mechanism in the present invention.

As shown in FIG. 2, the ball plunger 22 has a spring 24 and a ball 25 built in a cylindrical case 23 having a closed base end surface, and the ball 25 is elastically partially formed from the front end surface. It has a protruding structure. The ball 25 is prevented from jumping out of the case 23 by a caulking portion 26 formed on the distal end surface of the case 23. Therefore, the ball 25 of the ball plunger 22 is disposed on the inner periphery of the hole 14 of the cylindrical holder 13 in a state of being partially protruded by the elastic force of the spring 24. Note that the ball plunger 22 may be screwed into the hole 21, and in that case, the pressing force of the ball 25 can be adjusted by adjusting the screwing amount.

The one-way clutches 17 and 18 are roller type one-way clutches as shown in FIG.
Although FIG. 3 shows one one-way clutch 17, the other one-way clutch 18 has the same structure.

The one-way clutch 17 includes a cage 31 having a cylindrical shape as a whole, a plurality of rollers 32 held by the cage 31, and a shell 33 surrounding the outer periphery of the cage 31 so as to sandwich the roller 32 between the cage 31. It is composed of The retainer 31 has ribs 34 projecting radially at predetermined intervals in the circumferential direction.
Are formed. The roller 32 is held between the ribs 34, a part of the peripheral surface protrudes inward from the through hole 35, and is in contact with the outer peripheral surface of the end mill 19 inserted therein. A spring 36 is mounted on one surface of a rib 34 sandwiching the roller 32, and the spring 36 urges the roller 32 toward the other rib 34.

The shell 33 surrounds the outer periphery of the roller 32 with the roller 32 interposed therebetween.
Is held so as not to fall off from between the ribs 34 of the retainer 31. A cam surface 37 is formed on the inner periphery of a portion of the shell 33 where the rollers 32 are arranged. The cam surface 37 is formed of an inclined surface protruding inward in a direction in which the roller 32 is pressed by the spring 36. When the roller 32 moves in the above-described direction, the cam surface 37 and the outer peripheral surface of the end mill 19 are formed. Between roller 32
Is to be sandwiched.

Such a roller-type one-way clutch is already known, and for example, a "shell-type roller clutch" (trade name, manufactured by Nippon Seiko Co., Ltd.) can be used.

Next, the operation of this embodiment will be described.

The base end of the end mill 19 is connected to the cylindrical holder 13.
When the concave portion 20 formed on the outer periphery of the base end portion is fitted to the portion of the ball plunger 22, the ball 25 is elastically pressed against the concave portion 20 and fits into the end mill. The 19 cylindrical holder 13 is prevented from falling off. Also, if the end mill 19 is pulled strongly, the ball 25 compresses the spring 24 and pulls it outward and comes off the recess 20, so that the end mill 19 can be pulled out and removed. Therefore, with this fixing structure, the replacement operation of the end mill 19 can be performed quickly and easily.

On the other hand, with the end mill 19 attached to the cylindrical holder 13, the arbor 11 rotates forward and backward, and when the cylindrical holder 13 rotates integrally therewith, the action of the one-way clutches 17, 18 is as follows. End mill 19
Rotate together.

That is, in the one-way clutch 17, when the end mill 19 tries to rotate in the direction of the arrow in FIG.
Tries to rotate clockwise in the figure. For this reason, the roller 32 is connected to the cam surface 37 of the shell 33.
In the direction of the arrow in the figure. However, cam surface 3
The roller 32 is locked between the cam surface 37 and the outer peripheral surface of the end mill 19 because the roller 7 projects inward in that direction. Therefore, rotation of the end mill 19 with respect to the cylindrical holder 13 is prevented.

On the other hand, when the end mill 19 tries to rotate in the direction opposite to the arrow in the figure, the roller 32 in contact with the outer peripheral surface of the end mill 19 tends to rotate counterclockwise (counterclockwise) in the figure. For this reason, the roller 32 tends to move the cam surface 37 of the shell 33 in the direction opposite to the arrow in the figure. In that direction, the cam surface 37 is depressed outward and the distance between the cam surface 37 and the end mill 19 is widened, so that the rotation of the end mill 19 is not hindered, and the end mill 19 is attached to the cylindrical holder 13. Can be rotated with respect to.

However, in the present invention, since the other one-way clutch 18 described above has a structure in which the one-way clutch 17 is engaged in the opposite direction, the end mill 19 rotates in any direction with respect to the cylindrical holder 13. Attempting to do so is prevented from rotating by one of the one-way clutches 17 and 18.

Such one-way clutches 17, 18
The transmission of the rotation of the cylindrical holder 13 to the end mill 19 with almost no backlash causes the end mill 19 to come into contact with the workpiece, so that a strong load is applied to the rotational force or the load is reduced. Even if fluctuates greatly, without slipping or loosening,
Transmits torque reliably. On the other hand, when the end mill 19 is pulled out of the workpiece after the machining of the workpiece is completed, a force for pulling out the end mill 19 in the axial direction acts. However, since this force is relatively weak, the recess of the ball 25 described above is used. The end mill 19 is prevented from being detached from the cylindrical holder 13 by the fitting force to the cylindrical holder 13.

In the above-described embodiment, the retaining mechanism is such that an outer peripheral portion of a roller built in the cylindrical holder 13 is elastically fitted into an annular groove formed on the outer periphery of the end mill 19. A structure can also be adopted. Further, in order to more securely prevent the stopper from coming off, a structure is provided in which the cylindrical holder 13 and the end mill 19 are provided with a hole penetrating in a direction perpendicular to the axial direction, and a lock pin is inserted into this hole and fixed. Can also be adopted.

FIG. 4 shows another embodiment in which the structure for fixing a shaft or the like of the present invention is applied to a structure for fixing a bolt and a nut. In this embodiment, the bolt corresponds to the shaft or the like in the present invention, and the nut corresponds to the receiving member in the present invention.

In the figure, reference numerals 41 and 42 denote connected members which are arranged one above the other, and have holes 41a and 42a formed therein. The shaft portion 44 of the bolt 43 is inserted into the holes 41a and 42a. The shaft 4 of the bolt 43
4, it is not necessary that a thread groove is formed. On the other hand, the nut 45 combined with the bolt 43 has two one-way clutches 17 and 18 having different engagement directions pressed into the inner periphery. The nut 45 does not need to have a thread groove on the inner periphery. Further, an annular groove (not shown) is formed on the outer periphery of the distal end portion of the shaft portion 44 of the bolt 43, and the retaining ring 46 fits into this groove. The one-way clutches 17 and 18 have a structure similar to that of the above-described embodiment.

Therefore, the members to be connected 41 and 42 are overlapped, the shaft 44 of the bolt 43 is inserted into the holes 41a and 42a, and the protruding end of the shaft 44 is covered with the nut 45.
The shaft portion 44 is provided with a one-way clutch 17, 1 of a nut 45.
After being inserted through the nut 8, it protrudes from the upper surface of the nut 45. In the annular groove formed in this protruding portion, for example, E
A stop ring 46 made of a ring or the like is fitted, and the bolt 4
3 and the nut 45 are connected. According to such a fixing structure, it is not necessary to form thread grooves for bolts and nuts, and an advantage is obtained that the fixing can be performed without a tool.

[0033]

As described above, according to the present invention,
The shaft or the like can be fixed to the receiving member simply by inserting the end of the shaft or the like into the receiving member and preventing the shaft or the like from coming off by the retaining mechanism, so that attachment and detachment of the shaft or the like can be performed quickly and easily.
In addition, the shaft and the like can be prevented from rotating with respect to the receiving member by at least two one-way clutches arranged on the inner periphery of the receiving member and having different engagement directions, and can be rotated integrally with the receiving member. In this case, even if the load with respect to the rotational force fluctuates, the shaft and the like do not slip or come off with respect to the receiving member, and can be reliably held. Therefore, the present invention is applied to, for example, a structure for mounting a blade of a tool, thereby quickly and easily replacing a blade, improving workability, and causing the blade to loosen and idle or fall off during machining. Accidents can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment in which a fixing structure according to the present invention is applied to a tool blade mounting structure.

FIGS. 2A and 2B show a structure of a ball plunger used in the embodiment, in which FIG. 2A is a left side view, and FIG. 2B is a partially cutaway sectional view in which a half of the center is cut away.

FIG. 3 is a partially enlarged sectional view showing a structure of a one-way clutch used in the embodiment.

FIG. 4 is a sectional view showing another embodiment in which the fixing structure according to the present invention is applied to a fixing structure of a bolt and a nut.

[Explanation of symbols]

 11 Arbor 13 Cylindrical holder 17, 18 One-way clutch 19 End mill 20 Concave 25 Ball plunger 43 Bolt 44 Shaft 45 Nut 46 Stop ring

Claims (3)

(57) [Claims] In a fixing structure such as a shaft for inserting and fixing an end portion of a shaft or the like to an inner periphery of a receiving member, at least two one-way clutches having different engagement directions are mounted on an inner periphery of the receiving member. The shaft or the like is inserted into the inner periphery of the one-way clutch, and a retaining mechanism for preventing the shaft or the like from coming off in the axial direction from the receiving member is provided. 2. The retaining mechanism comprises a recess formed on the outer periphery of the shaft or the like, and an engaging member protruding from the inner periphery of the receiving member and elastically pressed against the outer periphery of the shaft or the like. A fixing structure for the shaft or the like according to claim 1. 3. The fixing structure for a shaft or the like according to claim 1, wherein the shaft or the like is a tool blade, and the receiving member is a chuck portion of the tool.