JP3856776B2 - Fastener removal protection device - Google Patents

Description

  The present invention relates to a fastener removal protection device that is applied to a fastener by screwing such as a bolt or a nut and that can prevent an outsider from accessing the torque transmission portion of the fastener.

  Conventionally, it has been widely practiced to assemble buildings such as steel towers and buildings using fasteners such as bolts and nuts, and to fix mechanical parts to facilities such as railways. In this fastening by screwing, it is easy to appropriately increase or decrease the fastening force by adjusting the fastening torque, and the fastening force can be readjusted as necessary even after the fastening is completed. Tools such as a spanner that transmit the fastening torque to the fastener are generally commercially available.

  Recently, there has been an incident in which someone intentionally removes a power transmission tower or railroad track fastening point. The conventional locking structure used at the bolt and nut fastening points cannot be protected until a malicious person releases the fastening state with a general tool such as a spanner.

  Therefore, various kinds of dedicated fastening part removal prevention tools have been proposed, and the latest one is a cover member that surrounds at least the torque transmission part from one side in the axial direction of the fastening tool and has a groove on the inner peripheral side. The outer peripheral portion is urged to fit into the groove on the inner peripheral side of the cover member, and is pressed from the outer peripheral side so that it can slide along the inner peripheral surface where the groove of the cover member is not formed. And a spring member whose diameter can be reduced and a restraining member that restrains the spring member in the axial direction of the fastener (see Patent Document 1).

  This fastening part removal preventing tool has the advantage that the structure is simplified and there is no component part protruding to the outside, and the bolt can be prevented from being removed on either the head side or the tip side. Since the insertion hole of the operating tool for driving in the direction of diameter reduction is formed through the side wall portion of the cover member, by inserting a thin metal rod from the side without using a regular operating tool Since anyone can easily drive the spring member and remove the cover member from the fastener, there remains a problem in terms of security.

Japanese Patent Laid-Open No. 2003-113829

  The problem to be solved is that it is possible to accurately prevent access to the torque transmission part of the fastener in the mounted state, and it can be easily removed if necessary by an authorized worker. The present invention requires the use of a member and a predetermined procedure that cannot be easily perceived in appearance, and therefore, it is intended to provide a fastener removal protection device with an improved security function.

The present invention is disposed between the fastener and the fastening object so as to be immovable in the axial direction of the fastener, and is fitted to the holder having the ball locking groove formed on the outer peripheral surface, the torque transmission portion of the fastener, and the holder, A cover inner cylinder that is capable of idling around the axis of the fastener and is formed by penetrating a ball receiving hole in the radial direction in the cylinder wall, and fitted into the cover inner cylinder, and can idle around the axis of the fastener and A cover outer cylinder that is movable in the axial direction and formed with a ball relief groove on the inner peripheral surface of the cylinder wall, and a ball of the holder is accommodated in the ball receiving hole of the cover inner cylinder so as not to drop into the inner space of the cover inner cylinder. Equipped between the cover inner cylinder and the cover outer cylinder, a cover whose inner part can be engaged with the locking groove and whose outer part can enter the ball escape groove of the cover outer cylinder, and the cover Direction to move the outer cylinder away from the object to be tightened The spring member to be moved and the relative movement of the cover inner cylinder and the cover outer cylinder are moved between a restraint position where the ball escape groove does not communicate with the ball receiving hole and a release position where the ball escape groove communicates with the ball receiving hole. It consists of regulating members to regulate,
When the cover outer cylinder moves to the release position, a keeper receiving groove that protrudes from the base end surface of the cylinder wall portion of the cover inner cylinder is formed on the inner peripheral surface of the cylinder wall portion of the cover outer cylinder, and the inner side is at the opening edge of the ball escape groove. When the ball pressed by the ball is engaged across the ball receiving hole and the ball locking groove, the inner cylinder of the cover is restrained by the holder, while the ball pressed outward at the opening edge of the ball locking groove is By engaging the ball receiving hole and the ball relief groove, the cover inner cylinder is released from the holder, and the tip of the keeper member inserted between the base end surface of the cylinder outer wall of the cover outer cylinder and the object to be tightened The main feature is that the cover outer cylinder is held in the release position by engaging the keeper with the keeper receiving groove.

  In the first aspect of the invention, when the cover outer cylinder is maintained in the restrained position by the action of the spring member, the ball is engaged across the ball receiving hole and the ball locking groove, so that the cover inner cylinder becomes the holder. Since it is restrained, the cover inner cylinder cannot be removed from the holder. Even if the cover outer cylinder is rotated by some means, the cover outer cylinder is idle with respect to the cover inner cylinder, and the cover inner cylinder is only idle with respect to the holder. I can't turn it. Therefore, the fastening state of the fastening object by the fastener is accurately maintained.

With an authorized keeper member inserted a regular keeper member between the tube wall of the cover outer cylinder and the object to be tightened, the cover outer cylinder is pressed toward the object to be tightened to the release position, The keeper receiving groove of the cover outer cylinder protrudes from the level of the cylinder wall of the cover inner cylinder, and then the keeper member is pulled back slightly to insert the tip of the keeper member into the keeper receiving groove, thereby releasing the cover outer cylinder. The cover inner cylinder is released from the holder by moving the cover inner cylinder away from the object to be tightened and engaging the ball across the ball receiving hole and the ball escape groove. The cover outer cylinder and the cover inner cylinder can be removed from the fastener and the holder.
In other words, when there is a need to replace mechanical parts or perform maintenance and inspection of the structure, if the prescribed keeper member is used in accordance with the prescribed procedure, the removal protection device can be securely removed and the fasteners removed or tightened. You can adjust the force.

  By simply repeating the pressing operation of the cover outer cylinder without using the keeper member, the inner cylinder of the cover is immediately returned to the restrained state by the action of the spring member, and this keeper member is normally expected. The keeper member is inserted at a position between the cover outer cylinder and the object to be tightened, and then slightly pulled back to apply the tip of the keeper member to the inner peripheral surface of the cover outer cylinder. The keeper member is engaged with a certain keeper receiving groove, and since such a keeper member and the operation procedure are not usually easily perceived in appearance, the security function is greatly improved.

  Since the ball engages with the ball locking groove of the holder, and it is not necessary to form the ball locking groove on the bolt or nut that is the fastener, the holder is placed under the existing nut or bolt head. By inserting, it can be additionally mounted on existing fastening points. The bolts and nuts do not need to be grooved, and can be immediately applied to the removal and protection of commercially available ordinary bolts and nuts.

  All holders, cover inner cylinders, cover outer cylinders, balls, and restricting members are made of metal material so that they are rigid against mechanical shocks. To do.

Example 1 is a case where the fastener is a bolt 19 and is shown in FIGS.
The holder 1 also serves as a first-stage nut member in a double-nut type tightening structure, and two opposite side surfaces 1a and 1b are cut into parallel surfaces as shown in FIGS. In addition, a rotary operation tool such as a spanner can be hung. Unlike the present embodiment, the holder 1 can be configured as a simple washer, or can be configured by a pedestal portion that is integrally formed from the fastening object 2.
A cam slope 3 having an inclination angle of 20 degrees is formed on the outer peripheral surface of the tip of the holder 1. The ball locking groove 4 is formed in an annular shape at a position slightly below the cam slope 3.

  A cam slope 6 having an inclination angle of about 45 degrees is formed on the outer peripheral surface of the front end portion of the cover inner cylinder 5. On the outer peripheral surface of the cylindrical wall portion of the cover inner cylinder 5, a regulation groove 8 into which the tip of the pin-shaped regulation member 7 is inserted is formed in an annular shape at a position slightly below the cam slope 6. A plurality of ball receiving holes 9 are formed at the base end of the cylindrical wall portion of the cover inner cylinder 5. A cam slope 10 having an inclination angle of about 45 degrees is formed on the inner peripheral surface of the lower end of the cylindrical wall portion. An annular recess 11 in the top wall portion of the cover inner cylinder 5 is formed, and a base end portion of a spring member 12 made of a compression coil spring is accommodated in this.

The cam slope 3 of the holder 1 and the cam slope 10 of the cover inner cylinder 5 serve as a guide when the cover inner cylinder 5 is fitted to the holder 1, and the cam slope 6 of the cover inner cylinder 5 connects the cover outer cylinder 13 to the cover inner cylinder. 5 is used as a guide when mating with 5.
The cover outer cylinder 13 has a truncated cone shape at the tip (invention of claim 2), and a circular depression 14 is formed on the top wall. The circular depression 14 accommodates the tip of the spring member 12. The pin serving as the restricting member 7 is driven and fixed in the radial through-hole 15 of the cover outer cylinder 13 and has a surface finish so that the boundary portion cannot be distinguished from the outer surface.
As described above, when the tip of the cover outer cylinder 13 is formed in a truncated cone shape, the tip of the tool slips on the conical surface even if a normal pinching tool such as a pliers is applied from the axial direction of the cover outer cylinder 12. As a result, the rotation of the cover outer cylinder 13 can be prevented.

The inner edge of the ball receiving hole 9 of the cover inner cylinder 5 is bent and deformed in a claw-like shape in the centripetal direction to prevent the ball 16 made of steel balls from dropping into the inner space of the cover inner cylinder 5. ing.
The cover inner cylinder 5 and the cover outer cylinder 13 are arranged with the outer peripheral surface of the cover inner cylinder 5 facing each other so as to be in close contact with the inner peripheral surface of the cover outer cylinder 13 (invention of claim 3). It has a cylindrical structure. Since the cover inner cylinder 5 functions as a backup member for the cover outer cylinder 13, the cover outer cylinder 13 is distorted and deformed even if the main body trunk surface of the cover outer cylinder 13 is pinched or hit by any means. Thus, there is no risk that the restraining function by the ball 16 is fatally lost.

As shown in FIG. 1, when the removal protection device of the present invention is mounted on the holder 1, the ball 16 is partially engaged with the ball locking groove 4 of the holder 1. The outer spherical surface of 16 is in contact with the inner surface of the cylindrical wall portion of the cover outer cylinder 13, and the ball 16 is engaged across the ball receiving hole 9 of the cover inner cylinder 5 and the ball locking groove 4 of the holder 1. . The relative position of the cover outer cylinder 13 at this time with respect to the cover inner cylinder 5 is accurately maintained by the front end portion of the regulating member 7 coming into contact with the upper wall surface 18 of the regulating groove 8 by the urging of the spring member 12. Therefore, the cover outer cylinder 13 cannot be shifted to the release position, and the cover inner cylinder 5 is firmly bound to the holder 1 via the balls 16.
Therefore, no one can access the torque transmission portion 20 that is the head portion of the bolt 19 surrounded by the cover outer cylinder 13 and the cover inner cylinder 5.

  When it is desired to remove the removal protection device, as shown in FIG. . In this state, the cover outer cylinder 13 is pressed toward the tightening object 2 against the bias of the spring member 12, and the base end surface of the cylinder wall portion of the cover outer cylinder 13 is brought close to the upper surface of the keeper member 21. . At this pressing position, the tip of the regulating member 7 is in contact with the lower wall surface 28 of the regulating groove 8, and the annular ball relief groove 23 of the cover outer cylinder 13 is formed in the ball receiving hole 9 of the cover inner cylinder 5. I have come to a released release position.

As shown in FIG. 3, the keeper member 21 is slightly pulled back while maintaining the pressing of the cover outer cylinder 13, thereby engaging the tip 22 of the keeper member 21 with the annular keeper receiving groove 24 of the cover outer cylinder 13. . As a result, the cover inner cylinder 5 and the cover inner cylinder 13 are integrally coupled and held by the urging force of the spring member 12, and the keeper member 21 is pulled up to be separated from the fastener 19 and the holder 1 as shown in FIG. Is done. In the initial stage of the sampling separation process, the ball 16 pushed by the opening edge of the ball locking groove 4 moves outward, and is engaged across the ball escape groove 23 and the ball receiving hole 9 as shown in FIG. Match.
An authorized worker can loosen the fastener 19 or tighten it tightly by putting a tool such as a spanner on the exposed fastener 19.

  When the keeper member 21 is detached from the keeper receiving groove 24 of the cover outer cylinder 13 from the state shown in FIG. 4, the relative position of the cover outer cylinder 13 and the cover inner cylinder 5 is changed in the extending direction by the action of the spring member 12. The transition ends when the tip of the regulating member 7 abuts against the upper wall surface 18 of the regulating groove 8. In the initial stage of the transition process, the ball 16 pushed by the opening edge of the ball escape groove 23 moves inward, and a part of the inside protrudes into the inner space of the cover inner cylinder 5.

At the stage where the change in the extending direction of the cover outer cylinder 13 and the cover inner cylinder 5 is completed, the ball escape groove 23 is in a restrained position where it does not communicate with the ball receiving hole 9. When the protection device in this state is attached to the holder 1 again, the cam inclined surface 3 of the holder 1 comes into contact with the part of the ball 16 that is held in a state where a part of the protection device protrudes inside the cover inner cylinder 5. In this state, when the cover outer cylinder 13 is pressed toward the object 2 to be tightened and the ball relief groove 23 is communicated with the ball receiving hole 9, the ball 16 moves outward and a part of the outer side becomes the ball relief groove 23. The cover inner cylinder 5 can pass through the portion of the cam slope 3 of the holder 1. When the pressure of the cover outer cylinder 13 is stopped when the ball receiving hole 9 of the cover inner cylinder 5 communicates with the ball locking groove 4 of the holder 1, the cover outer cylinder 13 is tightened 2 by the action of the spring member 12. The ball 16 is pushed inward by the opening edge of the ball escape groove 23 in the initial stage of the movement process, and a part of the inside of the ball 16 enters the ball locking groove 4 of the holder 1. As a result, the removal protection device is remounted as shown in FIG.

Example 2 is a case where the fastener is a stud bolt 25 and a nut 27, and is shown in FIGS.
An opening 17 from which the shaft portion of the stud bolt 25 protrudes is formed at the center portion of the top wall portion of the cam outer cylinder 13, and the shaft portion of the stud bolt 25 protrudes from the center portion of the top wall portion of the cover inner tube 5. Since the main part of the configuration is substantially the same as in the first embodiment except that the opening 26 to be formed is not formed, detailed description thereof is omitted. The holder 1 also serves as a first stage nut member in a double nut type tightening structure.

As shown in FIG. 5, in a state where the removal protection device is mounted on the holder 1, the ball 16 is engaged with a part of the ball locking groove 4 of the holder 1 and a part of the outer side covers the ball 16. The ball 16 is in contact with the inner peripheral surface of the outer cylinder 13 and is engaged across the ball receiving hole 9 of the cover inner cylinder 5 and the ball locking groove 4 of the holder 1. At this time, the relative position of the cover outer cylinder 13 with respect to the cover inner cylinder 5 is accurately maintained by the front end portion of the restriction member 7 coming into contact with the upper wall surface 18 of the restriction groove 8 by the action of the spring member 12. The cover outer cylinder 13 cannot shift to the release position, and the cover inner cylinder 5 is firmly connected to the holder 1 via the balls 16.
Therefore, no one can access the torque transmission portion of the nut 27 that is a fastener surrounded by the cover outer cylinder 13 and the cover inner cylinder 5.

  When the removal protection device is desired to be removed, the keeper member 21 is inserted from between the tube wall portion of the cover outer tube 13 and the fastening object 2 so as to abut against the outer surface of the base end portion of the holder 1 as shown in FIG. In this state, the cover outer cylinder 13 is pressed against the fastening object 2 against the spring member 12, and the base end surface of the cover outer cylinder 13 is brought close to the upper surface of the keeper member 21. In this pressing position, the tip of the restricting member 7 abuts the lower wall surface 28 of the restricting groove 8, and the ball relief groove 23 of the cover outer cylinder 13 is a release position communicating with the ball receiving hole 9 of the cover inner cylinder 5. Have come to.

As shown in FIG. 7, the tip portion 22 of the keeper member 21 is engaged with the keeper receiving groove 24 of the cover outer cylinder 13 by slightly pulling back the keeper member 21 while maintaining the pressing of the cover outer cylinder 13. As a result, the cover inner cylinder 5 and the cover inner cylinder 13 are integrally held by the spring member 12, and the keeper member 21 is pulled up and separated from the fasteners 19 and 25 and the holder 1 as shown in FIG. 8. . In the initial stage of the sampling separation process, the ball 16 pushed by the opening edge of the ball locking groove 4 moves outward, and is engaged across the ball escape groove 23 and the ball receiving hole 9 as shown in FIG. Match.
The worker can loosen or retighten the nut 27 by putting a tool such as a spanner on the exposed nut 27 as a fastener.

  When the keeper member 21 is removed from the keeper receiving groove 24 of the cover outer cylinder 13 from the state shown in FIG. 8, the relative position of the cover outer cylinder 13 and the cover inner cylinder 5 is changed in the extending direction by the spring member 12. 7 is brought into contact with the upper wall surface 18 of the restriction groove 8, and the transition is completed. In the initial stage of the transition process, the ball 16 pushed by the opening edge of the ball escape groove 23 moves inward, and a part of the inside protrudes into the inner space of the cover inner cylinder 5.

At the stage where the change in the extending direction of the cover outer cylinder 13 and the cover inner cylinder 5 is completed, the ball escape groove 23 is in a restrained position where it does not communicate with the ball receiving hole 9. When the protection device in this state is newly attached to the holder 1, the cam inclined surface 3 of the holder 1 comes into contact with a part of the ball 16 projecting inside the cover inner cylinder 5. In this state, when the cover outer cylinder 13 is pressed toward the object 2 to be tightened and the ball relief groove 23 is communicated with the ball receiving hole 9, the ball 16 moves outward and a part of the outer side becomes the ball relief groove 23. Get in. Thereby, the cover inner cylinder 5 can pass through the area of the cam slope 3 of the holder 1. When the pressing of the cover outer cylinder 13 is stopped when the ball receiving hole 9 of the cover inner cylinder 5 communicates with the ball locking groove 4 of the holder 1, the cover outer cylinder 13 is separated from the tightening object 2 by the spring member 12. In the initial stage of the moving process, the ball 16 is pushed inward by the opening edge of the ball escape groove 23, and a part of the inside of the ball 16 enters the ball locking groove 4 of the holder 1. The removal protection device is remounted as shown in FIG.
That is, the mounting operation of the removal protection device is automatically and quickly performed automatically by the covering operation of the cover inner cylinder 5 and the holder 1 and the pressing operation of the cover outer cylinder 13.

In the first and second embodiments, two keeper members 21 are prepared, and intermediate portions of the two elongated keeper members 21 are connected by a pivot pin 29 so as to be opened and closed like a hook (invention of claim 4). A finger ring 30 is formed at the base end of each keeper member 21. The front end portion of the cover outer cylinder 13 that engages and disengages with the keeper groove portion 24 is formed in a U-shaped cross section including the base material portion of the keeper member 21, and in use, the base material portion is the fastening object 2. The tip portions 22 and 22 which are inserted between the cover outer cylinder 13 and the fastening object 2 along the upper surface of the cover and bent in parallel with the base material portion via the rising portion are centered on the pivot pin 29. Since the keeper members 21 and 21 are opened and closed, the keeper members 21 and 21 are inserted into the keeper receiving groove 24 at the same time.
Further, if the pair of keeper members 21 and 21 are pulled up as they are, the cover inner cylinder 5 and the cover outer cylinder 13 can be moved smoothly and accurately without causing re-engagement between the ball 16 and the ball locking groove 4 itself. The fastener and the holder 1 can be extracted and separated, and operability is good.

It is a center longitudinal cross-sectional view of the mounting state of the removal protection apparatus which concerns on Example 1 of this invention. It is a center longitudinal cross-sectional view of the state which inserted the keeper member and pressed the cover outer cylinder from the state of FIG. FIG. 3 is a central longitudinal sectional view showing a state in which the keeper member is slightly pulled back from the state of FIG. FIG. 4 is a central longitudinal sectional view of a state in which the cover outer cylinder and the cover inner cylinder are integrally extracted from the holder and separated from the holder by the keeper member from the state of FIG. 3. It is a center longitudinal cross-sectional view of the mounting state of the removal protection apparatus which concerns on Example 2 of this invention. FIG. 6 is a central longitudinal sectional view of a state where a keeper member is inserted and a cover outer cylinder is pressed from the state of FIG. 5. FIG. 7 is a central longitudinal cross-sectional view of a state where the keeper member is slightly pulled back from the state of FIG. 6 and the tip of the keeper member is inserted into the keeper receiving groove of the cover outer cylinder. FIG. 8 is a central longitudinal cross-sectional view of a state where the cover outer cylinder and the cover inner cylinder are integrally separated from the holder by the keeper member from the state of FIG. 7. It is a top view of the holder used in common with Example 1 and Example 2 of this invention. It is a front view of the holder of FIG. It is a rear view of the holder of FIG. It is a top view of the cover inner cylinder used for Example 1 of the present invention. It is a center longitudinal cross-sectional view of the cover inner cylinder of FIG. It is a bottom view of the cover outer cylinder used for Example 1 of the present invention. It is a center longitudinal cross-sectional view of the cover outer cylinder of FIG. It is a top view of the keeper member used in common with Example 1 and Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Holder 2 Tightening object 3 Holder cam slope 4 Ball locking groove 5 Cover inner cylinder 6 Cam slope of cover inner cylinder 7 Restriction member 8 Restriction groove 9 Ball receiving hole 10 Cam slope of cover inner cylinder 11 Annular recess 12 Spring Member 13 Cover outer cylinder 14 Circular recess 15 Cover through cylinder through hole 16 Ball 17 Cam outer cylinder opening 18 Upper wall surface 19 of regulating groove 20 Torque transmitting part 21 Keeper member 22 Keeper member tip 23 Ball relief groove 24 Keeper receiving groove 25 Stud bolt 26 Cam inner cylinder opening 27 Nut 28 serving as fastener Fastener lower wall surface 29 Keeper member pivot pin

Claims (4)

A holder that is immovably disposed in the axial direction of the fastener between the fastener and the fastening object, and that is fitted to the holder having the ball engaging groove formed on the outer peripheral surface, the torque transmission portion of the fastener, and the holder. A cover inner cylinder that is capable of idling around and that is formed by penetrating a ball receiving hole in the radial direction in the cylinder wall, and fitted into the cover inner cylinder, can be idled around the axis of the fastener and can move in the axial direction of the fastener The cover outer cylinder in which the ball escape groove is formed on the inner peripheral surface of the cylinder wall portion, and the ball receiving hole of the cover inner cylinder are accommodated so as not to fall into the inner space of the cover inner cylinder, A part of the inner side can be engaged and a part of the outer side can enter the ball escape groove of the cover outer cylinder. Moving bias in the direction away from the attached object A restriction that restricts the relative movement of the spring member, the cover inner cylinder and the cover outer cylinder between a restraining position where the ball relief groove does not communicate with the ball receiving hole and a release position where the ball relief groove communicates with the ball receiving hole. Consisting of parts,
When the cover outer cylinder moves to the release position, a keeper receiving groove that protrudes from the base end surface of the cylinder wall portion of the cover inner cylinder is formed on the inner peripheral surface of the cylinder wall portion of the cover outer cylinder, and the inner side is at the opening edge of the ball escape groove. When the ball pressed by the ball is engaged across the ball receiving hole and the ball locking groove, the inner cylinder of the cover is restrained by the holder, while the ball pressed outward at the opening edge of the ball locking groove is By engaging the ball receiving hole and the ball relief groove, the cover inner cylinder is released from the holder, and the tip of the keeper member inserted between the base end surface of the cylinder outer wall of the cover outer cylinder and the object to be tightened A fastener removing / protecting device for engaging a keeper receiving groove to hold the cover outer cylinder in the released position.   The removal protection device according to claim 1, wherein the outer peripheral surface of the cover inner cylinder and the outer peripheral surface of the cover outer cylinder are arranged so as to face each other.   The removal protection device according to claim 1 or 2, wherein a front end portion of the cover outer cylinder is formed in a truncated cone shape.   The removal protection device according to claim 1, 2 or 3, wherein intermediate portions of the pair of keeper members are connected to each other by a pivot pin to form a hook shape.

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