JPH0666963U - Bolt tightening tool - Google Patents

Abstract

(57) [Summary] [Purpose] To increase the ejection force of the ejection pin for ejecting chips so that the cut chips can be ejected from the chip fitting part reliably. [Structure] Holding hole 11 for holding stopper 12
Further, a stopper drop-off preventing portion 13 for preventing the stopper 12 from falling off is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bolt tightening tool for tightening a bolt and a nut generally called shear bolt, and more particularly to a bolt tightening tool for preventing incomplete fitting of a tip of a bolt.

[0002]

[Prior art]

 This type of bolt tightening tool, commonly called a shear wrench, fits the tip of the bolt into the tip fitting part of the inner sleeve, and rotates the outer sleeve with the nut fitted by the drive device. When the nut is tightened against the bolt by moving the nut, and the nut is tightened with a certain torque, the nut on the inner sleeve side receives the nut's tightening reaction force by the outer sleeve to shear the chip. Has been done. In recent years, in order to prevent so-called sticking of the above-mentioned tip portion, a nut is fitted to the outer sleeve only when the tip is completely fitted to the tip fitting portion of the inner sleeve. There is, for example, the one disclosed in Japanese Patent Publication No. 52-36640.

This conventional chip incomplete fitting preventing technique will be described with reference to FIG. 7 which is shown with reference to FIG. 2 of the publication, in which the chip P is completely fitted and the ejection pin for ejecting the chip is ejected. When the carriage 20 is fully retracted, the spherical stopper 21 rolls down the inclined surface 22a formed at the tip of the large diameter portion 22 of the protrusion pin 20 and retracts from the outer peripheral surface of the inner sleeve 23, whereby the inner sleeve 23 is retracted. 23 is retractable with respect to the outer sleeve 24, and the nut N can be fitted into the outer sleeve 24. On the other hand, since the fitting of the tip P is incomplete, the ejection pin 20 is not fully retracted. In this case, the stopper 21 remains pushed toward the outer sleeve 24 (outer peripheral side of the inner sleeve 23) by the peripheral surface 22b of the large diameter portion 22 of the protruding pin 20. As a result, the inner sleeve 23 is prevented from retreating and the outer sleeve 24 cannot be fitted with the nut N.

[0004]

[Problems to be solved by the device]

 However, in the above-described conventional configuration, the holding hole 25 for holding the stopper 21 in the inner sleeve 23 does not restrict the movement of the stopper 21 in the vertical direction in the drawing (is not prevented from falling off). Therefore, in order to prevent the stopper 21 from falling off to the inner peripheral side of the inner sleeve 23, it is possible to further retract the ejecting pin 20 from the state where the stopper 21 rolls down on the inclined surface 22a of the large diameter portion 22. Therefore, the stroke of the protrusion pin 20 could not be sufficiently obtained. Incidentally, as shown in the figure, conventionally, a retaining ring 26 has been mounted to regulate the amount of retreat of the protrusion pin 20.

As described above, in the related art, since the ejecting pin 20 cannot be largely retracted to obtain a sufficient stroke, the ejecting amount cannot be sufficiently secured, and thus the ejecting force becomes insufficient and the tip becomes insufficient. In some cases, P was not reliably discharged.

Here, it is conceivable to lengthen the axial length of the large diameter portion 22 of the ejection pin 20 as a means for securing the sufficient retreat amount of the ejection pin 20 while preventing the stopper 21 from falling off. However, in this case, there is a problem that the captain of the fastener becomes long and difficult to handle.

Therefore, in the present invention, the stopper is prevented from coming off, and the retracting amount of the ejecting pin is sufficiently secured without increasing the machine length of the fastener, thereby increasing the ejecting force of the ejecting pin. An object of the present invention is to provide a bolt tightening tool capable of reliably ejecting a chip.

[0008]

[Means for Solving the Problems]

 For this reason, the present invention is characterized in that a holding hole for holding the stopper is provided with a stopper drop-out prevention portion for preventing the stopper from coming off. Specifically, the inner circumference of the inner sleeve is Along the circumferential direction of the surface, the ring member is attached to the inner peripheral side of the holding hole at the inner peripheral side opening of the inner sleeve, and the protruding portion is attached. It is characterized in that the stopper is prevented from coming off.

[0009]

[Action]

 According to the above configuration, the stopper is prevented from falling to the inner peripheral side of the inner sleeve by the stopper falling prevention portion provided in the holding hole. Even if the large-diameter part of the is disengaged, it does not fall off from the holding hole to the inner peripheral side of the inner sleeve. Therefore, the ejection pin can be sufficiently retracted and the stroke thereof can be sufficiently taken, whereby the ejection amount and thus the ejection force can be increased.

Further, since the length of the large diameter portion is not increased in order to increase the protrusion amount of the protrusion pin, the protrusion force of the protrusion pin can be increased without increasing the machine length.

[0011]

【Example】

 Next, an embodiment of the present invention will be described with reference to FIGS. In the figure, only the tip of the bolt tightening tool 1 of this example is shown, and the rear part (handle part) in which the drive motor, the operation switch and the like are incorporated is omitted.

In the figure, reference numeral 2 denotes a cylindrical outer sleeve rotatably supported at the tip of the housing 1 a of the bolt tightening tool 1. The outer sleeve 2 is transmitted through the planetary gear train 4. It is rotated by the driving force of the drive motor. A nut fitting portion 3 having a polygonal square hole for fitting a nut N to be tightened is formed on the inner periphery of the tip portion (the left end portion in the drawing) of the outer sleeve 2.

Next, on the inner peripheral side of the outer sleeve 2, a support sleeve 5 and an inner sleeve 6 each having a cylindrical shape are rotatably supported coaxially and independently of the outer sleeve 2. The support sleeve 5 is also rotated by the driving force of the drive motor transmitted through the planetary gear train 4.

The inner sleeve 6 is supported on the inner peripheral side of the support sleeve 5 through the spline 8, and therefore, the inner sleeve 6 rotates integrally with the support sleeve 5 and the support sleeve 5 supports the inner sleeve 6. It is possible to move in the axial direction. A compression coil spring 9 is mounted between the inner sleeve 6 and the support sleeve 5, whereby the inner sleeve 6 projects in the projecting direction on the inner peripheral side of the support sleeve 5, that is, the inner peripheral side of the outer sleeve 2. It is urged to the left).

A flange portion 6a is formed on the outer circumference of the tip of the inner sleeve 6, and the flange portion 6a abuts on the stepped portion 2a formed on the inner circumference of the tip of the outer sleeve 2, Further protrusion of the inner sleeve 6 is prevented.

On the inner peripheral surface of the tip of the inner sleeve 6 supported in this way, a serrated uneven surface corresponding to the peripheral shape of the chip P to be fitted is formed, and this portion is the chip P. Is used as a chip fitting portion 10 for fixing the bolt B to prevent the bolt B from rotating.

Further, holding holes 11 are formed so as to penetrate to the inner peripheral side at two positions which are opposed to each other in the circumferential direction in the rear portion of the inner sleeve 6, and the holding holes 11 are respectively formed in the holding holes 11. A steel stopper 12, which is a sphere having a diameter slightly smaller than that of the rear portion and having a diameter sufficiently larger than the thickness of the rear portion, is inserted.

On the other hand, on the inner peripheral surface of the rear portion of the inner sleeve 6, there is formed an annular groove portion in the circumferential direction which passes through the openings of the both holding holes 11 (the openings on the inner peripheral side of the inner sleeve 6). A metal ring 13 as a stopper drop-off preventing portion is mounted in the annular groove portion by utilizing the elastic force in the opening direction. The rings 13 slightly project to the inner peripheral sides of both the holding holes 11 to narrow the inner diameter of the holding holes 11 to a width in which the stopper 12 cannot pass. It is prevented from falling to the side. When the stopper 12 is received by the ring 13 (moved to the inner peripheral side of the inner sleeve 6) as shown by the one-dot chain line in FIG. The diameter of the stopper 12 or the thickness of the rear portion of the inner sleeve 6 is set so that the stopper 12 does not protrude from the inside.

Next, on the inner peripheral side of the inner sleeve 6, a protruding pin 15 for ejecting chips is supported so as to be movable in the axial direction. The protruding pin 15 is formed by coaxially stepping a pin portion 15a having a small diameter in a substantially left half of the center, a stepped portion 15b at a substantially center, and a large diameter portion 15c at a rear portion (right end in the drawing). It is shaped.

A compression coil spring 17 is also mounted between the protrusion pin 15 and the support sleeve 5, so that the pin portion 15 a of the protrusion pin 15 is integrally formed substantially at the center of the inner circumference of the inner sleeve 6. The guide ring 16 is biased in such a direction as to project into the chip fitting portion 10 through the insertion hole 16a of the guide ring 16.

The guide ring 16 is provided at a position that is recessed into the tip fitting portion 10 by a predetermined dimension, so that the fitting depth of the tip P with respect to the tip fitting portion 10 is larger than necessary. It is regulated. On the other hand, the left end surface in the figure of the stepped portion 15b of the protrusion pin 15 is a stopper surface 15d, and the stopper surface 15d abuts the right end surface in the figure of the guide ring 16 so that the protrusion pin 15 is necessary. The above-mentioned forward protrusion is restricted.

The large-diameter portion 15 c of the protrusion pin 15 is formed to have a diameter slightly smaller than the inner diameter of the rear portion of the inner sleeve 6, and the axial length thereof is a pin portion during the movement process of the protrusion pin 15. When the protruding portion 15a is in the tip fitting portion 10, it is always located just below the stopper 12 so that the stopper 12 protrudes from the outer peripheral surface of the inner sleeve 6 (the state shown in FIG. 1). Formed in length.

Therefore, when the protruding pin 15 is retracted and the pin portion 15a is retracted from the inside of the chip fitting portion 10 (see FIG. 3), the large diameter portion 15c is disengaged from directly below the stopper 12. The attaching portion 15b is located immediately below the stopper 12, and thereby the stopper 12 can move inside the holding hole 11 to the inner peripheral side of the inner sleeve 6.

When the protruding pin 15 is further retracted and the stepped portion 15b is also released from the position just below the stopper 12 (see FIG. 4), the stopper 12 is received by the ring 13 and the inner sleeve 6 It is held in a state of being positioned in the holding hole 11 without falling off on the circumferential side.

A rod 19 is connected to the rear portion of the protrusion pin 15. Although not shown, a hooking groove is formed at the rear end portion of the rod 19, and when the protrusion pin 15 is pushed in, the hooking groove is pulled to a hooking member provided in the rear portion of the housing. While the retracted position of the protruding pin is retained by being hooked, a handle lever (not shown) is provided with a tip lever, and by operating the tip lever, the locking of the hook member is released, As a result, the ejecting pin 15 is ejected forward by the compression coil spring 17.

The fastener 1 of this example is configured as described above, and according to this configuration, the following operational effects are achieved. That is, when the fastener 1 shown in FIG. 1 or 2 is not used, the inner sleeve 6 is pushed forward by the compression coil spring 9, and its flange portion 6a abuts the stepped portion 2a of the outer sleeve. It is in a state. The push-out pin 15 is pushed out in the push-out direction by the compression coil spring 17, and its stopper surface 15d abuts on the right end surface of the guide ring 16 in the figure, so that its pin portion 15a is inserted into the insertion hole 16a of the guide ring 16. After that, it is in a state of protruding into the chip fitting portion 10.

When the protrusion pin 15 is thus protruded, the peripheral surface of the large-diameter portion 15c of the protrusion pin 15 is located immediately below the stopper 12, as shown in the figure. Is pushed up in the holding hole 11 by the peripheral surface of the large-diameter portion 15c and is projected from the outer peripheral surface of the inner sleeve 6. When the stopper 12 is in this state, the stopper 12 comes into contact with the end surfaces of the teeth of the spline 8 formed on the inner peripheral surface of the support sleeve 5 to prevent the inner sleeve 6 from retreating. There is.

To use the tightening tool 1 in the above state for tightening the bolt B, first, the chip P of the bolt B is fitted into the chip fitting portion 10 of the inner sleeve 6. Then, along with this, the protrusion pin 15 is gradually retracted against the compression coil spring 17. In this process, since the axial length of the large diameter portion 15c of the ejecting pin 15 is formed to have a constant dimension as described above, the stopper 12 is pushed up in the retaining hole 11 in the ejecting direction. Therefore, the inner sleeve 6 is not retracted because the inner sleeve 6 is prevented from retracting by the stopper 12. As a result, the nut N cannot be fitted into the nut fitting portion 3 while the chip P is in the incompletely fitted state, and the incomplete fitting of the chip P is prevented.

Further, when the tip P is fitted into the tip fitting portion 10 and the tip P is brought into contact with the guide ring 16 to be in a completely fitted state, the pin portion 15 a of the ejecting pin 15 has a tip fitting portion 10 a. The large-diameter portion 15c of the protrusion pin 15 is pushed out from the inside, and is disengaged from immediately below the stopper 12, and instead, the stepped portion 15b is positioned directly below the stopper 12. As a result, the stopper 12 can move inside the holding hole 11 to the inner peripheral side of the inner sleeve 6, and the engagement between the stopper 12 and the end surface of the tooth of the spline 8 formed on the support sleeve 5 is released. Therefore, the inner sleeve 6 can be moved in the axial direction with respect to the outer sleeve 2.

In this way, the inner sleeve 6 becomes movable, and the nut N can be fitted in the nut fitting portion 3 of the outer sleeve 2. That is, when the tightening tool 1 is pressed, the inner sleeve 6 retracts against the outer sleeve 2 against the compression coil spring 9, and accordingly, the nut N gradually enters the nut fitting portion 3 of the outer sleeve 2. It will be mated. In this process, the positional relationship between the inner sleeve 6 and the protruding pin 15 does not change.

When the nut N is completely fitted in the nut fitting portion 3 as shown in FIG. 3, the inner sleeve 6 and the protruding pin 15 are pushed into the innermost part, and At this time, the above-mentioned hooking member is hooked in the hooking groove of the rod 19 connected to the rear portion of the ejecting pin 15, whereby the ejecting pin 15 is locked in this position and its axial movement is prevented. It becomes a state.

As described above, since the tip P of the bolt B is completely fitted in the tip fitting portion 10, the bolt B is prevented from rotating, and thus the nut N can be tightened. Then, when the drive motor is driven by operating the trigger of the handle (not shown), the outer sleeve 2 rotates without rotating the inner sleeve 6, and the nut N is tightened into the bolt B. Go.

When the nut N is sufficiently tightened and an external torque of a certain level or more is applied to the outer sleeve 2, the rotation of the outer sleeve 2 is locked, and instead, the inner sleeve 6 receives a rotational force due to its reaction force. Granted. At this time, since the nut N of the bolt B is sufficiently tightened to make it unrotatable, when a rotational force is applied to the inner sleeve 6, stress due to this force concentrates on the cutting portion of the chip P, As a result, the tip P is sheared from the shaft portion of the bolt B at this cut portion.

With the above, the tightening work of the nut N is completed, and when the tightening tool 1 is moved to remove the nut N from the nut fitting portion 3, first, the inner sleeve 6 is moved by the compression coil spring 9 accordingly. The inside of the outer sleeve 2 is moved relatively forward. At this time, since the ejecting pin 15 is locked by the above-mentioned hook member, it does not move. Therefore, the ejecting pin 15 is gradually separated from the inner circumference of the inner sleeve 6.

When the inner sleeve 6 moves further forward and its flange portion 6a comes into contact with the stepped portion 2a of the outer sleeve 2 and returns to the original position, the movement of the inner sleeve 6 is stopped, and the fastening tool is further tightened. When 1 is moved, the nut N does not come off from the nut fitting portion 3. At this time, the cut tip P is left in the tip fitting portion 10 of the inner sleeve 6 and separated from the shaft portion of the bolt B.

In this way, when the nut N is completely removed from the nut fitting portion 3, the inner sleeve 6 is located at the original position of the front portion of the outer sleeve 2 while the protruding pin 15 is It is locked in the deepest position. Therefore, the large-diameter portion 15c and the stepped portion 15b of the protrusion pin 15 are completely displaced from directly below the stopper 12. However, since the stopper 12 is prevented from falling off to the inner peripheral side of the inner sleeve 6 by the ring 13, the stopper 12 is in the state of being positioned in the holding hole 11 without falling off.

When the tip lever is operated to release the lock of the rod 19 by the hooking member after the above state, the ejecting pin 15 is ejected forward by the compression coil spring 17, so that the pin portion 15a is The chip P that has been left in the chip fitting portion 10 and ejected is discharged. At the same time, the large-diameter portion 15c of the protrusion pin 15 is located immediately below the stopper 12, and the stopper 12 is held again in a state of being protruded from the outer peripheral surface of the inner sleeve 6, so that the inner sleeve 6 and the support sleeve 5 are retained. That is, a state in which relative movement in the axial direction with the outer sleeve 2 is prevented (a state in which the tip P is incompletely fitted is prevented).

As described above, according to the fastener 1 of this example, the stopper 12 for restricting the axial movement of the inner sleeve 6 is disengaged from the inner peripheral side of the inner sleeve 6 by the ring 13. Since it is surely prevented from coming off, even if the large diameter portion 15c of the protrusion pin 15 is largely deviated from directly below the stopper 12 as shown in FIG. There is nothing to do.

Therefore, the axial length of the large diameter portion 15c is such that the stopper 12 projects from the outer peripheral surface of the inner sleeve 6 only while it is necessary to prevent the incomplete fitting of the chip P. Therefore, the axial length of the large diameter portion 15c can be significantly shortened as compared with the conventional one.

Since the axial length of the large diameter portion 15c can be shortened, the stroke of the ejecting pin 15 can be increased without increasing the length of the fastening tool 1 and the ejecting pin 15 The larger the stroke is, the larger the ejection force is. Therefore, the cut chips P remaining in the chip fitting portion 10 can be reliably discharged from the chip fitting portion 10.

In this example, a metal ring 13 having elasticity in the opening direction is exemplified as the stopper disengagement prevention portion for preventing the stopper 12 from disengaging to the inner peripheral side of the inner sleeve 6. As described above, the present invention is not limited to this, and may be made of resin instead of metal, and instead of this ring 13, for example, a rubber O-ring may be provided at the same position and in the same state. It may be configured to be adhered. Further, although not shown, a retaining piece may be attached to the inner opening of the inner sleeve 6 of the holding hole in a state of protruding to the inner peripheral side of the holding hole. When the large diameter part is located directly below the stopper, this stopper is allowed to protrude from the outer peripheral surface of the inner sleeve. Regardless of the position of the inner sleeve, it may be held inside the holding hole to prevent the inner sleeve from falling off.

[0042]

[Effect of device]

 According to the above configuration, the stopper for restricting the axial movement of the inner sleeve to prevent the incomplete fitting of the tip is prevented from falling off to the inner peripheral side of the inner sleeve by the stopper falling prevention member. Therefore, it is not necessary to prevent the stopper from falling off by the large diameter part of the protruding pin as in the past, and therefore the length of the large diameter part in the axial direction can be greatly shortened to reduce the machine length of the fastener. It is possible to increase the stroke of the ejection pin and increase the ejection force without increasing the length of the ejection pin, which in turn makes it possible to reliably eject the cut tip from the tip fitting portion.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a tip portion of a fastener according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a tip portion when the fastener is not used.

FIG. 3 is a vertical sectional view showing a state in which the tip and the nut are completely fitted together.

FIG. 4 is a vertical cross-sectional view showing a state in which the nut has been tightened and the chip has been cut.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is an enlarged view of a C portion of FIG. 1, and is a vertical cross-sectional view showing a state in which the stopper is prevented from falling off.

FIG. 7 is a vertical cross-sectional view of a tip portion of a fastening tool, which is related to a conventional stopper dropout prevention structure and is shown with reference to FIG. 2 of Japanese Patent Publication No. 52-36640.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bolt tightening tool (shear wrench) 2 ... Outer sleeve 3 ... Nut fitting part 5 ... Support sleeve 6 ... Inner sleeve 10 ... Chip fitting part 11 ... Retaining hole 12 ... Stopper 13 ... Ring (stopper fall prevention part) 15 ... Protruding pin 15a ... Pin portion, 15b ... Stepped portion, 15c ... Large diameter portion B ... Bolt (shear bolt) P ... Tip N ... Nut

Claims (2)

[Scope of utility model registration request] 1. An outer sleeve having a nut fitting portion, and an inner sleeve having a tip fitting portion movably supported in the outer sleeve in an axial direction.
A tip ejecting pin, which is supported in the inner sleeve so as to be movable in the axial direction, and a stopper are retained on the side wall of the inner sleeve so that the stopper can be retracted and retracted. A bolt tightening tool having a mechanism for preventing incomplete fitting of a tip that restricts movement of a sleeve with respect to the outer sleeve, wherein the holding hole for holding the stopper prevents the stopper from falling off. A bolt tightening tool that is provided with a stopper falling prevention part. 2. A ring member is extended along the circumferential direction of the inner peripheral surface of the inner sleeve toward the inner peripheral side of the holding hole at the opening of the inner peripheral side of the inner sleeve of the holding hole. The bolt tightening tool according to claim 1, wherein the stopper is attached and the protruding portion is used as the stopper drop-off preventing portion.