JP2006175523A - Socket for rotary tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a socket for a rotary tool, improving the durability without local image on a shaft member even if large turning torque or impact force of an impact driver or the like is applied thereto, and using the conventional device. <P>SOLUTION: This socket for a rotary tool includes: a socket member 1 having a shaft fitting hole 1a of a hole axis parallel to the axial direction at the axial trailing end; and a shaft member fitted and fixed to the shaft fitting hole 1a of the socket member 1 and extended backward, wherein the engagement of the shaft fitting hole 1a and the shaft member 2 is varied between the leading end and the trailing end, whereby the interference after fitting and fixing of the socket member 1 and the shaft member 2 in the shaft fitting hole 1a is set smaller at the trailing end side of the shaft fitting hole 1a and larger at the leading end side to fit and fix the shaft member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotary tool socket that is replaceably attached as an attachment to the tip of a power rotary tool such as an electric / charge driver or an air driver.

This type of rotary tool socket has a small-diameter shaft member for gripping the rotary chuck of a power rotary tool at the rear end of the cylindrical socket member, and the tip is fitted with a bolt / nut head It has a structure having a fitting hole.
The shaft member is required to have high rigidity so as to be gripped by the rotary chuck of the power rotary tool and to reliably transmit the rotational torque to the socket member. In order to satisfy such a requirement, a high-rigidity metal material such as high alloy steel is required. And a heat treatment to provide wear resistance, high toughness, and high hardness. The socket member is made of a metal material different from that, and a shaft fitting formed at the rear end of the socket member is used. There is known a rotary tool socket in which the shaft member is press-fitted into a hole and fixedly coupled (for example, see Patent Document 1).

Further, conventionally, the shaft member fitting hole at the rear end of the socket member has a diameter larger than that of the shaft member, and the shaft member is inserted into the shaft member fitting hole, and the hole shaft of the shaft member fitting hole is provided in the socket member. A method of manufacturing a socket for a rotary tool is proposed in which external pressure is applied from the direction and the outer peripheral direction to cause plastic flow in the socket member and the shaft member is fixed to the shaft portion fitting hole by pressure (Patent Document 2). .
JP-A-6-226651 JP-A-9-248635

However, in the rotary tool socket of Patent Document 1, the shaft member is press-fitted and fixed to the shaft portion fitting hole from the front end side to the rear end side with substantially the same tightening allowance. In such a case, a rotational torsional stress is generated in the shaft member, and this torsional stress concentrates and acts near the rear end of the socket member, and the shaft member tends to be locally damaged at the portion such as cracks and breaks. In the case of an impact driver, this tendency is more remarkable because impact forces in the rotational direction and the axial direction are applied.
Further, the manufacturing method of Patent Document 2 cannot use a conventional device as it is, and requires a special press device for applying external pressure to the socket member from the axial direction and the outer peripheral direction of the shaft portion fitting hole. In addition, many types of this device must be prepared for each size of the rotary tool socket, the manufacturing equipment is bulky and the cost is high, and the shaft member and the shaft portion fitting hole are crimped in the axial direction. It is not easy to set the force distribution according to the target, and it is difficult to prevent the shaft member from being damaged due to local damage at the rear end position of the shaft fitting hole. There is.

  The present invention has been developed in view of the above-mentioned problems of conventional rotary tool sockets, and the object of the present invention is to provide a shaft member that is a socket member even when a large rotational torque or impact force such as an impact driver is applied. An object of the present invention is to provide a rotary tool socket that can improve durability without being locally damaged at the rear end position, and can be used as it is by a conventional apparatus.

In order to achieve the above object, the present invention provides a socket member having a shaft portion fitting hole having a hole axis parallel to the axial direction at the rear end in the axial direction, and is fitted and fixed to the shaft portion fitting hole of the socket member. A shaft member extending rearward, and changing the fit between the shaft portion fitting hole and the shaft member between a front end and a rear end, thereby the shaft of the socket member and the shaft member. It is characterized in that the fastening allowance after fitting and fixing in the part fitting hole is set and fixed so as to be small at the rear end side of the shaft part fitting hole and large at the tip side.
According to the above configuration, even if a large rotational torque or impact force (impact force in the rotational direction and axial direction) such as an impact driver is applied to the shaft member, the tightening allowance at the shaft portion fitting hole between the shaft member and the socket member is reduced. Since the rear end side is set smaller than the front end side and is fixed, the stress generated in the shaft member can be distributed to the front end side without being concentrated at the rear end position of the shaft portion insertion hole. The shaft member can be improved in durability without being locally damaged at the socket member rear end position (the shaft portion fitting hole rear end position). Moreover, by changing the fit between the shaft member fitting hole and the shaft member at the front end and the rear end, the tightening allowance between the shaft member and the shaft member fitting hole can be easily set as desired, The durability of this type of rotary tool socket can be reliably improved. In addition, the conventional apparatus can be used as it is, and an increase in cost can be avoided.

In addition, the shaft member has at least a portion of the shaft portion fitted into the shaft portion fitting hole having a square shaft shape, and the shaft portion fitting hole is a circular hole, The hole diameter on the end side is the same as or slightly smaller than the diagonal dimension of the shaft member, and the hole diameter on the tip side of the shaft portion fitting hole is approximately the same as the opposite side dimension of the shaft member. It is said.
According to this configuration, the binding stress distribution after fitting and fixing in the shaft portion fitting hole between the socket member and the shaft member is small, and the tightening margin on the rear end side of the shaft portion fitting hole is small and the tightening margin on the tip side is small. It is possible to easily carry out the press-fitting or the like to set it to be large and fix it.

The shaft portion fitting hole is formed in a plurality of stages or tapered so that the hole diameter is gradually reduced from the rear end toward the tip side, and the shaft member is at least the shaft portion fitting. The fitting portion in the hole is characterized in that it is uniformly formed in the axial direction with a radial direction dimension that is the same as or slightly larger than the diameter of the rear end side of the shaft portion fitting hole.
According to this configuration, the shaft fitting hole can be easily formed by a step drill or a taper drill, etc., and the tightening allowance after fitting and fixing in the shaft fitting hole between the socket member and the shaft member can be reduced. In addition, it is possible to easily carry out the fitting by setting it to be small at the rear end side of the shaft portion fitting hole and to be large at the tip end side by press fitting or the like.

Further, the shaft member is formed in a plurality of stages or in a tapered shape so that at least a fitting portion of the shaft member into the shaft portion fitting hole gradually decreases in the radial direction from the front end side toward the rear end side. The shaft fitting hole is characterized in that it is a circular hole that is the same as or slightly smaller than the radial dimension of the small diameter portion on the rear end side of the shaft member and is uniform in the axial direction.
According to this configuration, it is possible to reduce the tightening allowance after the fixing of the shaft portion fitting hole between the socket member and the shaft member by changing the radial dimension on the shaft member side. It is possible to easily carry out the fitting and fixing so as to be small on the side and large on the tip side by shrink fitting, tightening from the outer peripheral direction, or the like.

In addition, the shaft member has at least a square shaft-shaped fitting portion in the shaft portion fitting hole, the shaft portion fitting hole is a circular hole, and a tip of the shaft portion fitting hole. The hole diameter on the side is substantially the same as the opposite side dimension of the shaft member, the hole diameter on the rear end side is larger than the diagonal dimension of the shaft member, and the shaft member is at the tip end side of the shaft portion fitting hole. The socket member is directly fitted and fixed, and the rear end side is fitted and fixed to the socket member through a buffer sleeve made of a soft material different from the socket member.
According to this configuration, by appropriately selecting the material of the buffer sleeve, the fitting condition between the shaft portion fitting hole and the shaft member is appropriately changed between the front end and the rear end, so that the shaft member and the shaft portion fitting hole can be changed. The bond strength can be easily set as desired.

Moreover, in this invention, the socket member (1) which has the axial part fitting hole (1a) of the hole axis line parallel to this axial direction in the axial direction rear end, and the said axial part fitting of this socket member (1) A shaft member (2) that is fitted and fixed in the hole (1a) and extends rearward, and the shaft member (2) and the shaft portion fitting hole (1a) are formed by the shaft portion fitting hole. The front end side of (1a) is an interference fit, and the rear end side is fitted and fixed by a clearance fit.
According to this configuration, when the tightening operation is performed by an impact driver, a bending force combined with the axial direction as well as the rotational direction acts on the shaft member, but the shaft corner portion is on the rear end side of the shaft portion fitting hole. Torque is transmitted while sliding while sliding against the inner surface of the hole in which the clearance is fitted, greatly reducing stress concentration on the shaft member at the rear end position of the shaft fitting hole. Thus, the durability of the shaft member can be improved.

  According to the present invention, even if a large rotational torque or impact force such as an impact driver is applied, the shaft member is not locally damaged at the rear end position of the socket member, and durability can be improved. Thus, it is possible to provide a rotary tool socket in which a conventional device can be used as it is.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1A, the rotary tool socket of the present invention includes a socket member 1 and a shaft member 2 that is fitted and fixed to the rear end side of the socket member 1 and extends rearward. Yes. The socket member 1 is formed into a stepped cylindrical shape by machining or die forging by wear-resistant high alloy steel (soft hardness), and a shaft portion fitting hole having a hole axis line parallel to the axial direction at the rear end in the axial direction. A regular hexagonal hole-shaped fitting hole 1b is formed on the axial tip of the bolt and nut head, and is formed coaxially with the shaft fitting hole 1a. The joint hole 1b communicates with these through a hollow hole 1c coaxially therewith. Before the socket member 1 is fitted to the shaft member 2, a rust-proofing treatment different from the color of the shaft member 2, such as a colored anti-rust surface treatment such as brass plating (electrolytic plating), is performed. It is easy to determine the quality of the product, the quality indication is clear, the customer's choice can be ensured, and the durability and design can be improved to improve the quality. .

The shaft member 2 is die-forged with a high alloy steel (high hardness) having wear resistance and toughness so that the cross section is a regular hexagonal square shaft and has a uniform cross sectional shape in the axial direction. As shown to (A), the front end side is made into the fitting part 2a to the axial part fitting hole 1a of the socket member 1, and the rear end side is made into the mounting part 2b to the rotary chuck of a power rotary tool, and a locking groove 2c is formed.
A circumferential groove 2d having a wedge-shaped cross section in the axial direction is formed on the outer periphery of the distal end portion of the fitting portion 2a, and the distal end (small diameter portion) 2e is a circle having a slightly smaller diameter than the opposite side dimension A1 of the regular hexagonal shaft portion of the shaft member 2. It is a cross section. That is, a tip 2e having a small cross-sectional area is formed on the tip side of the hexagonal portion of the fitting portion 2a, and a peripheral groove 2d in the vicinity thereof, and the bottom of the peripheral groove 2d is gradually shallower toward the tip 2e side. Is formed. In addition, the shaft member 2 is shot blasted, and the entire surface is subjected to antirust coloring treatment such as blackening treatment, so that durability is improved with a predetermined hardness setting.

  In the first embodiment, as shown in FIG. 2A, the shaft fitting hole 1a at the rear end of the socket member 1 is a two-stage circular hole 1a1 having a small diameter at the front end and a large diameter at the rear end. 1a2 and these are coaxial, and the diameter of the circular hole 1a1 on the front end side is substantially the same as the opposite side dimension A1 of the regular hexagonal shaft portion of the fitting portion 2a of the shaft member 2, and the rear end The hole diameter of the side circular hole 1a2 is the same as or slightly smaller than the diagonal dimension A2 of the regular hexagonal shaft portion of the fitting portion 2a of the shaft member 2, and the shaft member 2 to be fitted with this has at least The fitting portion 2a has a regular hexagonal cross section that is uniform in the axial direction.

  By setting such a fitting relationship, the tightening allowance after fitting and fixing in the shaft fitting hole 1a between the socket member 1 and the shaft member 2 is indicated by a broken line in FIG. It can be fixed by setting the side to be small and the tip side to be large. In addition, as shown in FIG. 3A, the shaft portion fitting hole 1a of the socket member 1 may be a coaxial circular hole 1a1, 1a2, 1a3 whose hole diameter changes in three steps, and further includes three steps. As described above, by forming in multiple stages in this way, it is possible to fit and fix with a coupling strength as shown by the oblique lines in FIG.

  In order to fit and fix the shaft member 2 in the shaft portion fitting hole 1a of the socket member 1 shown in FIG. 2 (A), the fitting portion 2a of the shaft member 2 is fixed to the shaft portion fitting hole of the socket member 1. Press-fit into 1a from the rear end side. In this case, the circular hole 1a2 on the rear end side of the shaft fitting hole 1a has a hole diameter that is the same as or slightly smaller than the diagonal dimension A2 of the regular hexagonal shaft of the fitting part 2a of the shaft member 2. The shaft member 2 is inserted with little resistance until it reaches the circular hole 1a1 on the front end side, but from there onward, a pair of regular hexagonal shaft portions on the rear end side of the circumferential groove 2d at the front end of the shaft member 2 is inserted. The tip of the corner portion bites into the inner wall surface of the circular hole 1a1 on the distal end side and is press-fitted while cutting the inner wall surface (because the hardness of the shaft member 2 is higher than the hardness of the socket member 1). As shown in D), it is integrally fitted and fixed, and is fitted with a predetermined tightening allowance.

The shavings on the inner wall surface are clogged and compressed in the circumferential groove 2d, and the shavings are pressed against the inner surface of the circular hole 1a1 on the distal end side by the wedge-shaped circumferential surface of the circumferential groove 2d. Is provided with a function of preventing the slipping off. Accordingly, the shaft member 2 can be reliably prevented from coming off, and even when the impact force in the rotational direction and the axial direction is received like an impact driver, the fitting portion 2a of the shaft member 2 and the shaft portion of the socket member 1 are provided. No looseness occurs between the fitting hole 1a and the shaft member 2 does not come out.
Thus, the fitting portion 2a of the shaft member 2 is lightly contacted (inscribed) or is fitted with a small tightening allowance as shown in FIG. 1C with respect to the circular hole 1a2 on the rear end side. The As a result, it is realized that the fastening allowance after fitting and fixing in the shaft portion fitting hole 1a between the socket member 1 and the shaft member 2 is set and fixed so that the rear end side is small and the front end side is large. As a result, stress is prevented from concentrating at the rear end position of the shaft portion fitting hole 1a of the shaft member 2 even when a large rotational torque or impact force in the rotational direction of the impact driver or the like is applied to the shaft member 2. The stress can be distributed to the front end side in the shaft fitting hole 1a, and the shaft member 2 can be improved in durability without being locally damaged at the rear end position of the socket member 1. it can.

  In the case of the embodiment of FIG. 3 (A) in which the shaft portion fitting holes 1a of the socket member 1 are formed in three stages of large, medium and small, the shaft strength can be reduced by reducing the coupling strength on the rear end side of the shaft portion fitting holes. Although stress at each corner of the member (2) is relieved, the stress is concentrated at the axial corner of the coupling portion on the tip side. Therefore, the concentrated stress applied to the shaft corner can be smoothly relieved by forming the shaft fitting hole 1a in three stages of large, medium, small and absorbing the stress in stages. As a result, the shaft member 1 is further prevented from being locally damaged at the rear end position of the socket member, and the durability can be further improved.

  FIG. 4 shows a third embodiment of the present invention. In the third embodiment, the shaft portion fitting hole 1a of the socket member 1 is a circular hole uniform in the axial direction, and the shaft member 2 is By using a method such as shrink fitting and tightening from the outer peripheral portion as a shaft portion of a large and small two-step cross-sectional area in which the front end side 2a1 is large and the rear end 2a2 side is small in the radial direction dimension of the fitting portion 2a, The coupling strength similar to that of the first embodiment is obtained, and local damage is prevented from occurring at the rear end of the shaft fitting hole of the shaft member 2, thereby improving the durability. In this case, the fitting part 2a of the shaft member 2 has the opposite side dimension on the front end 2a1 side substantially the same as the diameter of the shaft part fitting hole 1a of the socket member 1, and the rear end 2a2 side is a pair of the shaft member 2 pair. It is preferable to delete the respective corners of the corners and make the diagonal dimension after deletion be the same as or slightly larger than the hole diameter of the shaft fitting hole 1a. Note that the radial dimension of the fitting portion 2a of the shaft member 2 from the front end to the rear end can be sequentially reduced, for example, three or more stages can be used. Thus, the coupling strength on the rear end side of the shaft fitting hole 1a is reduced stepwise, for example, as shown in FIG. Concentrated stress at is relaxed smoothly. Furthermore, if it is made into a taper shape, the concentrated stress in the said corner | angular part can be relieve | moderated more smoothly.

  FIG. 5 shows a fourth embodiment of the present invention. In the fourth embodiment, the shaft member 2 has at least one fitting portion 2a in the axial direction in the shaft fitting hole 1a. The shaft portion fitting hole 1a is a circular hole, and the diameter of the shaft portion fitting hole 1a on the tip 1a1 side is the fitting size of the shaft member 2. The opposite-side dimension of the regular hexagonal shaft portion of the portion 2a is the same or slightly smaller, the hole diameter on the rear end 1a2 side is larger than the diagonal dimension of the regular hexagonal shaft portion of the fitting portion 2a of the shaft member 2, and In the shaft fitting hole 1a on the rear end 1a2 side, a buffer sleeve 3 having an inner diameter substantially equal to the opposite side dimension of the regular hexagonal shaft portion of the fitting portion 2a of the shaft member 2 (the outer diameter is free) ), The buffer sleeve 3 is made of a soft material different from the socket member 1, and the shaft member 2 is In the shaft portion fitting hole 1a of the tip 1a1 side the directly fitted and fixed to the socket member 1, and is fitted and fixed to the socket member 1 through the impingement sleeve 3 at the rear end 1a2 side.

  The buffer sleeve 3 is made of a plastic material such as urethane, rubber, or a soft metal material such as copper or aluminum. The buffer sleeve 3 provides a coupling strength between the socket member 1 and the shaft member 2. The rear end side of the shaft portion fitting hole 1a is made smaller than the front end side, so that the shaft member 2 is less likely to be locally damaged at the rear end position of the shaft portion fitting hole, that is, the rear end position of the socket member. This is intended to improve durability. The buffer sleeve 3 may be formed separately in advance, or the melted material may be poured into the gap between the socket member 1 and the shaft member 2 to be cured.

FIG. 6 shows a fifth embodiment of the present invention. In the fifth embodiment, the shaft member 2 and the shaft portion fitting hole 1a are interference-fitted on the distal end side of the shaft portion fitting hole 1a. (See FIG. 6 (C)), and the rear end side is fitted and fixed by clearance fitting (FIG. 6 (B)).
The reason for adopting this embodiment is as follows. Conventionally, the breakage of the shaft member 2 is generally sheared obliquely from the rear end to the front end side of the shaft portion fitting hole 1a of the socket member 1. This is because the impact force of the impact driver is not necessarily applied only in the rotational direction, but also works in the direction in which the shaft member 2 bends. In order to greatly improve, it is necessary to mitigate the damage in the bending direction. In the fifth embodiment of the present invention, the minimum allowable dimension of the circular hole 1a2 on the rear end side of the shaft fitting hole 1a is set to be the maximum allowable dimension of the diagonal dimension of the shaft member 2, and the gap The fitting was to cause variations in direction. Thereby, the buffering action of the concentrated stress in the direction in which the rotation direction and the axial direction applied to the shaft member 2 are combined can be managed.

  The impact driver's impact direction is considered by the following impact structure example. FIG. 7 shows a structure example of a general impact driver. The impact driver 10 includes a motor 11 that is a power source and a drive shaft 13 that rotates by power transmitted from the motor 11 via the speed reduction mechanism 12 in a housing 14. A substantially annular hammer 15 is slidably fitted on the outer peripheral surface of the rim, and a spring 16 is disposed behind the hammer 15 to give a forward biasing force to the hammer 15. Further, a drive shaft cam groove 13a is formed in a substantially V shape that opens rearward on the outer peripheral surface of the drive shaft 13, and a hammer cam groove 15a is linearly formed in the axial direction on the inner peripheral surface of the hammer 15. The transmission steel ball 17 is positioned in a space formed between the bent portion of the substantially V-shape of the drive shaft cam groove 13a and the rear end portion of the hammer cam groove 15a. The rotational motion of the shaft 13 is transmitted to the hammer 15 via the transmission steel ball 17. However, as the front-rear relationship here, the side where the drive shaft 13 is located with respect to the motor 11 is the front side, and the opposite side is the rear side.

The front end portion of the drive shaft 13 is connected to the rear end portion of the anvil 18 so as to be rotatable. The front end of the hammer 15 and the hammer engaging portion 19 projecting in the radial direction from the rear end portion of the anvil 18 are forwardly provided. The rotational movement of the hammer 15 is transmitted to the anvil 18 by engaging with the hammer claw 20 projecting from the anvil. The front end side of the anvil 18 protrudes from the housing 14, and a bolt and a nut can be rotated by attaching a socket to the protruding portion.
When a certain load or more is generated on the anvil 18 during operation and the rotation is slow, the drive shaft cam groove having a substantially V shape is formed at the fitting portion between the transmission steel ball 17 and the drive shaft cam groove 13a. The steel ball 17 for transmission is pushed down along either of the groove directions of 13a, and in conjunction with this, the hammer 15 retreats on the drive shaft 13 against the urging force of the spring 16, and the hammer pawl 20 and the hammer The engagement portion 19 is disengaged. At this time, the hammer 15 continues to rotate, whereas the anvil 18 stops, the hammer 15 is pushed back by the restoring force of the spring 16, and the hammer pawl 20 engages with the hammer engaging portion 19 again. In doing so, the anvil 18 is hit by the rotation of the hammer 15 at the engagement location.

The hammer 15 that has received the reaction force due to the impact retreats against the urging force of the spring 16, and then gives the next impact to the anvil 18 by the restoring force of the spring 16 and the rotational force of the drive shaft 13. In this way, when a load exceeding a certain level is generated during operations such as screw tightening, the hammer 15 is repeatedly struck to generate a strong torque.
The hit by the hammer 15 is not always transmitted efficiently in the rotational direction, but the hit is also applied in the axial direction of the anvil 18 at the moment when the hammer 15 is pushed back by the restoring force of the spring 16.

  As described above, in the case of the impact driver, the hit is transmitted in the direction in which the rotation direction and the axial direction are combined. Therefore, the stress concentration of the shaft member is not necessarily applied only to the rotation direction of the shaft member, but also works in the direction in which the shaft member bends. Even when the shaft member 2 is clearance-fitted on the rear end side of the shaft portion fitting hole 1a of the socket member 1 by such a force in the bending direction (the fifth embodiment shown in FIG. 6), it is diagonal. As a result, the shaft corner portion contacts the inner surface of the hole and rubs or slips, and the stress concentration of the shaft member 2 is alleviated.

In addition, although all illustrated embodiment has illustrated the case where the front-end | tip of the socket member 1 is made into the regular hexagon hole fitted to a volt | bolt nut nut, this invention is not limited to this. The present invention can also be applied to rectangular holes, elliptical holes, and other shapes of holes, and can also be applied to cylindrical drill bits such as hole saws and core drills.
The connection between the socket member 1 and the shaft member 2 may be press fitting, shrink fitting, cold fitting, tightening from the outer peripheral portion, or the like. Further, the bond strength may be changed stepwise or continuously.

When the fracture endurance test and the tightening torque test of the shaft member of the six types of the embodiment product and the comparison product shown in the rotary tool socket according to the present invention were performed, the results shown in FIGS. 7 and 8 and Table 1 were obtained. . Use a pneumatic impact tool (air pressure: 0.6 MPa, output torque: 350 N.m) as a power rotary tool,
Deep hole: Conventional product,
Deep hole +20: In the conventional product, the extension length of the shaft member extended from the rear end of the socket member is increased by 20 mm,
A (counterbore): the embodiment of the present invention shown in FIG.
B (light press fit): the embodiment product shown in FIG. 2 of the present invention with the rear end light press fit,
C (urethane): the embodiment of the present invention shown in FIG.
D (brass): the embodiment product shown in FIG.
It carried out about.

Advancement of the present invention by preparing a deep hole + shaft length 20 mm longer in fracture durability test and torque test, and examining the relaxation degree of concentrated stress and torque damping rate due to shaft torsion (torsion effect) The sex was confirmed.
The embodiment product of the present invention is a conventional product having the same shape deep hole (conventional product) as in FIG. 1, and A is 4.1 times, B is 5.7 times, C is 6.9 times, and D is 2 It was confirmed that the durability was 7 times. Further, when comparing the damping rate, the deep hole + shaft length increased by 20 mm and the embodiment product B of FIG. 2 of the present invention have the same damping rate of about 21% in torque, but the fracture durability The test result was 419 seconds when the deep hole + axis length was increased by 20 mm, while that of the product of the embodiment B was 1077 seconds. As a result, the present invention does not improve the durability due to the twist of the shaft member, and can improve the durability without being locally damaged by the shaft corner portion. In consideration of the impact direction, the rear end has a clearance fit, but it is 4.1 times more durable than a conventional product with a deep hole similar to that shown in FIG. It could be confirmed.

  In the fracture durability test, the power rotary tool was used, and the durability time (s) until the shaft member was broken with the tip of the socket member fixed was measured. The results are as shown in FIG. 8 and Table 1. In addition, the tightening torque test was performed using the power rotary tool, a digital torque tester (YET-5001C) attached to the tip of the socket member via an adapter, and a timer: 2 seconds, torque (Nm) Was measured. The results are as shown in FIG. 9 and Table 1.

(A) is a partially broken side view showing the first embodiment of the rotary tool socket according to the present invention, (B) is an end view seen from the rear end side, (C) (D) (E) is respectively They are XX sectional drawing, YY sectional view, and ZZ sectional drawing. (A) The vertical side view of the socket member in the 1st Embodiment of this invention, (B) is explanatory drawing of the joint strength in a axial part fitting hole. (A) is a vertical side view of the socket member showing the second embodiment of the present invention, and (B) is an explanatory view of the coupling strength in the shaft portion fitting hole. It is a vertical side view of the disassembled state of the shaft member and socket member which shows the 3rd Embodiment of this invention. (A) is the partially broken side view which shows 4th Embodiment of the socket for rotary tools which concerns on this invention, (B) is the WW sectional view taken on the line. (A) is a longitudinal sectional side view showing a fifth embodiment of the rotary tool socket according to the present invention, (B) is an explanatory diagram of clearance fitting of the shaft member at the rear end portion of the shaft portion fitting hole, (C) is It is an interference fitting explanatory view of a shaft member in a tip part of a shaft part fitting hole. It is a principal part schematic sectional drawing which shows an example of the power rotary tool used by this invention. It is a graph which shows the fracture durability test result of this invention goods. It is a graph which shows the fastening torque test result of this invention goods.

Explanation of symbols

1 Socket member 1a Shaft fitting hole 2 Shaft member 3 Buffer sleeve

Claims (6)

  A socket member (1) having a shaft fitting hole (1a) having a hole axis parallel to the axial direction at the rear end in the axial direction, and fitting into the shaft fitting hole (1a) of the socket member (1) A shaft member (2) that is fixed and extends rearward, and by changing the fit between the shaft portion fitting hole (1a) and the shaft member (2) at the front end and the rear end, The tightening allowance after fitting and fixing in the shaft portion fitting hole (1a) between the socket member (1) and the shaft member (2) is reduced on the rear end side of the shaft portion fitting hole (1a), A rotary tool socket characterized in that it is set to be large on the tip side and is fixedly fitted.   In the shaft member (2), at least a fitting portion to the shaft portion fitting hole (1a) has a rectangular shape, and the shaft portion fitting hole (1a) is a circular hole, The hole diameter on the rear end side of the shaft part fitting hole (1a) is the same as or slightly smaller than the diagonal dimension of the shaft member (2), and the hole diameter on the tip side of the shaft part fitting hole (1a) is The rotary tool socket according to claim 1, wherein the socket member has a dimension substantially the same as the opposite dimension of the shaft member (2).   The shaft portion fitting hole (1a) is formed in a plurality of stages or tapered so that the hole diameter is gradually reduced from the rear end toward the front end side, and the shaft member (2) includes at least the The fitting portion to the shaft portion fitting hole (1a) is uniformly formed in the axial direction with the same or slightly larger radial dimension as the hole diameter on the rear end side of the shaft portion fitting hole (1a). The socket for a rotary tool according to claim 1, wherein the socket is a rotary tool.   The shaft member (2) is continuously provided in a plurality of stages or tapered so that at least a fitting portion to the shaft portion fitting hole (1a) gradually decreases in the radial direction from the front end side toward the rear end side. The shaft portion fitting hole (1a) is a circular hole that is the same as or slightly smaller than the radial direction size of the small diameter portion on the rear end side of the shaft member (2) and is uniform in the axial direction. The socket for a rotary tool according to claim 1, wherein the socket is for a rotating tool.   In the shaft member (2), at least a fitting portion to the shaft portion fitting hole (1a) has a rectangular shape, and the shaft portion fitting hole (1a) is a circular hole, The hole diameter on the front end side of the shaft portion fitting hole (1a) is substantially the same as the opposite side dimension of the shaft member (2), and the hole diameter on the rear end side is made larger than the diagonal dimension of the shaft member (2). The shaft member (2) is directly fitted and fixed to the socket member (1) on the front end side of the shaft portion fitting hole (1a), and is composed of a soft material different from the socket member (1) on the rear end side. The rotary tool socket according to claim 1, wherein the rotary tool socket is fixedly fitted to the socket member (1) through a buffer sleeve (3).   A socket member (1) having a shaft fitting hole (1a) having a hole axis parallel to the axial direction at the rear end in the axial direction, and fitting into the shaft fitting hole (1a) of the socket member (1) A shaft member (2) that is fixed and extends rearward, and the shaft member (2) and the shaft portion fitting hole (1a) are arranged on the tip side of the shaft portion fitting hole (1a). A rotary tool socket characterized in that it is an interference fit and is fixed by a clearance fit on the rear end side.

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