JP6377105B2 - Tension / traction material length adjuster - Google Patents

Description

  The present invention relates to a tension / traction material length adjusting device, and more particularly, an adjustment for adjusting the length of a tension / suspension or suspension material (hereinafter referred to as tension / traction material) such as a chain or rope. Relates to the device.

  When constructing work scaffolds at civil engineering construction sites, etc., there is a construction method that uses multiple steel pipes for laying scaffolding plates, and hangs both ends of these steel pipes from chains and the like with chains to adjust them. It has been adopted. In order to support a plurality of steel pipes approximately horizontally, this erection method lays scaffolding plates between the steel pipes, and if there is a lack of length or slack in the chain that suspends them, It is a method of adjusting the length of the chain.

  For such chain length adjustment, special tools such as turnbuckles are usually used. However, in recent years, other tools have begun to be used instead of these turnbuckles, and various devices have been developed accordingly. Proposed tools have been proposed.

  For example, Patent Document 1 below proposes an improved adjustment tool. Hereinafter, the chain length adjusting tool described in this patent document will be described with reference to FIG. FIG. 10 is a partially longitudinal side view of the adjustment tool described in Patent Document 1 below.

  As shown in FIG. 10, a chain length adjusting tool 1A described in Patent Document 1 includes a bolt 1 having a predetermined thickness and length, and an engagement on the head side mounted on the head 1b of the bolt. A member 2 and an engagement member 3 on the distal end side mounted on the distal end side are provided. Reference numeral 1c indicates a washer. Among these engaging members 2 and 3, the engaging member 2 on one head side is formed by bending a plate material such as an iron plate, and includes a cylindrical portion 4 penetrating the bolt shaft portion 1a, The plate member both ends extending portions 5a and 5b that are extended laterally from the cylindrical portion 4 and are fixed to each other, and the hook portion 6 formed by these plate material both ends extending portions 5a and 5b; , And an enlarged diameter portion 7 formed at a central position in the length direction of the cylindrical portion 4. The enlarged diameter portion 7 includes a parallel wall portion sandwiching the parallel side surfaces of the nut 8 so that the nut 8 is concentric with the axial center of the tubular portion 4 and cannot rotate and move in the axial direction around the axial center. An annular groove 7b for nut gripping is formed.

  Further, the other end side engaging member 3 is the same as the head side engaging member 2, and a nut 8 in which a female screw hole 8a is formed to be screwed into the bolt shaft 1a is incorporated. It has become. That is, the nut 8 has a parallel side surface sandwiched in the enlarged diameter portion 7 by a parallel wall portion (not shown) of the enlarged diameter portion 7, and the nut 8 has an annular recess for gripping the nut inside the enlarged diameter portion 7. A bolt shaft 1 a that fits into the groove 7 b and penetrates through the cylindrical portion 4 is fixed so as to threadably penetrate the female screw hole 8 a of the nut 8.

  According to the chain length adjusting tool 1A having this configuration, the hook portion 6 of the head-side engaging member 2 and the hook portion 6 of the distal end-side engaging member 3 are engaged with two links on the upper and lower sides of the chain to be adjusted. By doing so, both the engaging members 2 and 3 are prevented from rotating around the bolt shaft portion 1a by the chain to be adjusted. In this state, by rotating the bolt 1 in the fastening direction, the engagement member 3 on the distal end side is pulled toward the engagement member 2 on the head side that contacts the bolt head 1b, and the hook portion of each engagement member is pulled. It is possible to narrow the distance between the upper and lower portions of the adjustment target chain 6 engaged with the adjustment target chain and moderately tension the adjustment target chain.

Japanese Patent Laid-Open No. 2006-070572 Japanese Patent No. 3917007

  However, in the chain length adjusting tool 1A described in the above-mentioned Patent Document 1, the pair of engaging members 2 and 3 on the head side and the tip side rotate relative to the bolt shaft 1a so as to be different from each other. Therefore, when the chain is hooked, the engaging member rotates and is difficult to hook, and when it is hooked, it rotates during the work, making it difficult for one person to work. In addition, although the hardware which put such an engaging member in the groove | channel of a guide rail, and controls rotation is already well-known (refer the said patent document 2), it differs in a use and cannot be diverted to the adjustment tool 1A. .

  In addition, since each of the engaging members 2 and 3 has a hook portion formed by pressing a single plate material (such as an iron plate), there is an advantage in that it is lightweight, but it is a plate material pressing process. Therefore, mechanical strength is difficult. Furthermore, since these engaging members 2 and 3 have no retaining or the like, the hooked chain may jump out of the hook portion and come off.

  By the way, during the past period of high economic growth, Japan has developed a large amount of social capital (infrastructure) such as roads, bridges, dams and ports, and these have supported high economic growth and subsequent economic growth. Since infrastructure structures are generally constructed of cement and reinforcing bars, they have been deteriorated or damaged in recent years due to various effects such as secular changes, changes in the social environment, natural disasters such as typhoons and earthquakes. First of all, countermeasures are needed.

  This measure mainly consists of periodic inspections and diagnoses of structures and appropriate repairs and reinforcements based on the results. However, inspections and diagnoses of bridges and the like are at high places several tens of meters from rivers. Therefore, it will be a high place work with a work scaffold installed there, and it will contain various dangers, and it is necessary to take thorough safety measures. Although this safety measure covers many limbs such as workers' skills, work processes, equipment used and scaffolding construction plates, pipes and accessories, it is also related to human life and is extremely safe. Is required. Therefore, for example, when a chain length adjusting tool as described in the above-mentioned patent document is used for constructing a work scaffold in such a high place, thorough safety measures are required.

  The present invention has been made to solve the above-described problems of the prior art and to ensure the required high safety. That is, an object of the present invention is to provide a tension / traction material length adjusting device having excellent workability and durability, and having safety in conformity with international safety standards.

In order to achieve the above object, the tension / traction material length adjusting device according to the first aspect of the present invention has a bolt head at one end and a male screw engraved on the outer peripheral surface extending a predetermined length from the bolt head. A long bolt having a bolt shaft formed therein, a hollow hole through which the bolt shaft is inserted, and a cover case having a gap groove in the length direction of the outer peripheral wall; and the long bolt and the holder With fixed and movable hooks to be fitted,
The fixing hook includes a cylindrical body provided with an insertion hole through which the bolt shaft is inserted and fixed into the hollow hole of the holder, and a hook portion fixed to the cylindrical body and protruding from the gap groove. A hook body,
The movable hook is inserted into the hollow hole of the holder, and has a cylindrical body provided with a screw hole in which an internal thread is engraved with the male screw of the bolt shaft on the inner peripheral wall; A hook body provided with a hook portion fixed to the body and protruding from the gap groove,
The fixed hook is inserted into the holder from one end of the hollow hole so that the hook portion protrudes from the gap groove and is fixed to the end of the cover case, and the movable hook is inserted from the other end of the hollow hole. The hook portion protrudes from the gap groove and is movably inserted. The long bolt is inserted through the insertion hole of the fixed hook fixed to the holder, and is movably mounted on the holder. Screwed into the screw hole of the movable hook ,
The assembly set of the holder and the long bolt is mechanically deformed before the fixed and movable hooks when an excessive load is applied to at least one of the fixed and movable hooks. To do.

The tension / traction material length adjustment device according to the second aspect of the present invention is the tension / traction material length adjustment device according to the first aspect, wherein the long bolt and the holder are made of plain steel, Both the fixed and movable hooks are formed of a forged molded body made of carbon steel .

The tension / traction material length adjustment device according to a third aspect of the present invention is the tension / traction material length adjustment device according to the first aspect, wherein the long bolt is inserted into the holder and the length is adjusted. It is characterized in that a retaining member having a shape or size different from that of the bolt head is attached to the tip of the shank bolt .

A tension / traction material length adjusting device according to a fourth aspect of the present invention is the tension / traction material length adjustment device according to the first aspect, wherein a fixed stopper is attached to the fixed and movable hooks. and said that you are.

The tension / traction material length adjusting device according to a fifth aspect of the present invention is the tension / traction material length adjustment device according to the first aspect , in which the bolt head is coupled to a tool. It is characterized by having a shape .

The tension / traction material length adjustment device according to the first aspect of the present invention comprises a tension / traction material length adjustment device, a long bolt engraved with a male screw, a fixed and movable hook, and a holder, This holder is equipped with long bolts and fixed and moving hooks, so it has high durability and safety that meets international safety standards such as the 3-step method of ISO / ECO guide 51. In addition, the operability is significantly improved compared to the conventional one.
In addition, when a load exceeding the limit is applied to the device, the assembly set of the holder and the long bolt is mechanically deformed before the fixed and movable hooks. It can be determined that the adjusting device exceeds the allowable value. Appropriate countermeasures, such as reduction of overload and replacement of the tension / traction material length adjustment device, can be used to predict damage to the existing tension / traction material length adjustment device. Accidents can be prevented.

The 3-step method of the ISO / ECO guide 51 is as follows.
A inherently safe design
B Protective devices
C Notification to users (information for users)

According to the tension / traction material length adjusting device of the second aspect of the present invention, since the fixed hook and the movable hook are both formed of a forged molded body equivalent to carbon steel S45C, they are formed of plain steel. Strength is higher than long bolts and holders.

According to the tension / traction member length adjusting device of the third aspect of the present invention, the long bolt is inserted into the holder, and the tip of the long bolt has a shape or size different from that of the bolt head. Since the stop member is mounted, an excessive load is applied to the device, and even if the long bolt is bent into a bow shape, the bolt shaft is prevented from jumping out from the gap groove of the holder. Moreover, the retaining member is not rotated by mistake with the bolt head.

According to the tension / traction material length adjusting device of the fourth aspect of the present invention, the chain can be securely hooked, while the jumping out of the hooked chain can be prevented.

According to the tension / traction material length adjusting device of the fifth aspect of the present invention, the bolt head is shaped to be coupled with the tool, so that the work can be performed efficiently.

It is a perspective view of a tension / traction material length adjusting device concerning an embodiment of the present invention. 2A is a perspective view of a long bolt, FIG. 2B is a perspective view of a flat washer, and FIG. 2B is a perspective view of a retaining member. It is a perspective view of a holder. 4 shows a fixing hook, FIG. 4A is a side view, FIG. 4B is a top view, and FIG. 4C is a partial sectional view as seen from the back of FIG. 4A. 5 shows a movable hook, FIG. 5A is a side view, FIG. 5B is a top view, and FIG. 5C is a partial cross-sectional view as seen from the back of 5A. It is a perspective view in the state where a plurality of steel pipes were suspended by a plurality of tension / traction material length adjusting devices. It is a side view of a state where a chain is hooked on the upper and lower ends of the tension / traction material length adjusting device. It is a side view explaining the load applied to a tension / traction material length adjusting device. It is a test result figure of the stroke with respect to a load load of a tension / traction material length adjusting device. It is a partial longitudinal cross-sectional side view of the chain length adjustment tool of a prior art.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment shown below exemplifies a tension / traction material length adjusting device such as a chain and a rope for embodying the technical idea of the present invention, and the present invention is specified thereto. And is equally applicable to other embodiments within the scope of the claims. Although the following embodiment will be described as applied to a suspension chain, the present invention is not limited to this, and can be applied to towing or suspension with a rope (including wire rope). .

With reference to FIG. 1, an outline of a tension / traction material length adjusting device according to an embodiment of the present invention will be described. FIG. 1 is a perspective view of a tension / traction material length adjusting device according to an embodiment of the present invention.
The tension / traction member length adjusting device 10 according to the embodiment of the present invention includes a bolt head 11a at one end and a relatively long bolt shaft 11b having a predetermined length extending from the bolt head and engraved with a male screw 11c. long and long bolts 11, the bore 12 ₀ and the outer peripheral wall 12a linear gap grooves 12 ₁ cross-sectional shape substantially C-shaped having a the length of the (see FIG. 3) of the bolt shaft 11b is inserted therein with A holder 12 made of a pipe, a long bolt 11 and a pair of fixed hook 13A and movable hook 13B attached to the holder 12, and the other end 12c (see FIG. 3) of the holder 12 are brought into contact with the long bolt 11 It comprises a flat washer 16 and a retaining member 17 that allow the distal end portion 11d (see FIG. 2A) to rotate freely.

  The tension / traction material length adjusting device 10 has the above-described configuration, thereby having excellent workability and durability and, for example, an international safety standard such as the 3-step method of the ISO / ECO guide 51. It also has safety that meets the requirements.

  Hereinafter, with reference to FIGS. 1 to 5, individual members constituting the tension / traction material length adjusting device will be described. 2A is a perspective view of a long bolt, FIG. 2B is a perspective view of a flat washer, FIG. 2B is a perspective view of a retaining member, FIG. 3 is a perspective view of a holder, FIG. 4 is a fixing hook, and FIG. 4B is a top view, FIG. 4C is a partial sectional view as seen from the back of FIG. 5A, FIG. 5 shows a movable hook, FIG. 5A is a side view, FIG. 5B is a top view, and FIG. It is the fragmentary sectional view seen from.

  As shown in FIG. 2A, the long bolt 11 has a bolt head 11a at one end and a predetermined thickness and length with a predetermined length extending from the bolt head 11a and a predetermined male screw 11c engraved on the outer periphery. The bolt shaft 11b and the flat washer 16 are loosely fitted, and a tip end portion 11d to which the retaining member 17 is attached is formed by a bar-shaped metal material processed body.

  The bolt head 11a of the long bolt 11 preferably has a shape that can be rotated by mounting an electric tool or the like, for example, a hexagonal shape. The length of the long bolt 11 is not particularly limited and may be arbitrary. In this embodiment, for example, the length (full length) is 408 mm, the bolt head height is 8 mm, and the bolt shaft length. Is 400 mm, and the thickness (diameter) of the bolt shaft 11b is 12 mm, and the metal material is equivalent to general structural rolled steel (hereinafter also referred to as ordinary steel) SS400.

Flat washer 16, as shown in Figure 2B, has a predetermined outer shape and height, made from a coin-shaped having a through bore 16 ₀ is formed of a metal material. The flat washer 16 has an outer diameter larger than that of the holder 12. Moreover, insertion holes 16 ₀ is formed of a through-hole that is slightly larger than the diameter of the bolt shaft 11b, when the member 17 retaining the distal end of the bolt shaft 11b is fixed, rotating the tip portion 11d of the elongated bolt 11 It has a flexible structure. The flat washer 16 hits the end surface of the holder 12 when an excessive load is applied to the apparatus and the long bolt is bent into a bow shape, and the bolt shaft 11b is pulled outward in the axial direction. blocking the gap grooves 12 ₁ rush out to the outside. That is, the bolt shaft 11b is expanding Mizoguchi clearance groove 12 ₁ of the holder 12 is jumping out to the outside is prevented.

The retaining member 17 is a member that is fixed to the distal end portion 11d of the bolt shaft 11b and prevents the long bolt 11 from coming out of the holder 12. The retaining member 17 is a nut that is screwed to the distal end portion 11d, or a pressure that is pressed. It is a fitting material etc. (refer FIG. 2C). Incidentally, reference numeral 17 ₀ denotes a screw hole. The retaining member 17 is preferably a member that can be detachably attached to the tip 11d of the bolt shaft 11b. By making it detachable, it becomes possible to disassemble the tension / traction material length adjusting device 10 and to facilitate replacement or maintenance of parts.

  This retaining member has a different shape from the bolt head of the bolt shaft, for example, if the bolt head is hexagonal, other square or round shapes or different sizes, and a removable plastic or rubber cap It is preferable that a tool for rotating the bolt head is not attached. As a result, the tool is accidentally attached to the retaining member and removed from the tip of the bolt shaft, so that the long bolt does not come out.

Holder 12, as shown in FIG. 3, the linear gap grooves 12 ₁ in the longitudinal direction of the bolt shaft 11b size is inserted of the bore 12 ₀ and the outer peripheral wall 12a of the elongated bolt 11 therein It has a substantially C-shaped pipe (cover case) and is formed by bending a short side and a long side with a predetermined length and a substantially rectangular metal plate with a predetermined thickness. That is, a rectangular metal plate is curved so that both long sides edge from its longitudinal direction to approach, the gap grooves 12 ₁ between the bore 12 ₀ and both long side ends of predetermined size therein Is curved so that is formed.

Clearance grooves 12 _1, its width slightly wider than the thickness of the hook body 13 of the movable hook 13B, together with the cylindrical body 14 of the movable hook is prevented from flying out to the outside, the movement of the length direction The guide groove is smooth. The groove width of the gap groove 12 _1, preferably in the range obtained by adding positive 1.0~2.0mm the thickness of the hook body 13. This is because if it is less than 1.0 mm, the guide of the movable hook 13B will not be smooth, while if it exceeds 2.0 mm, it will be easy to open. The holder is not limited to a pipe having a substantially C-shaped cross section, and may be a cover case having another shape, for example, a square shape.

  The holder 12 covers the long bolt 11 so that the bolt shaft will not be damaged by hitting the bolt shaft, and the effect will be maintained when oil is poured, and the operator can directly touch the bolt shaft. It is easier to grip the strip. In particular, the holder plays an important role in preventing the hook from popping out by expanding the gap groove when an excessive load is applied to the hook. Further, as will be described later, the fixed hook 13A and the movable hook 13B are formed of a carbon steel forged molded body, and the holder 12 and the long bolt 11 (assembly set S) are formed of ordinary steel. The strength of the forged molded body of 13A and the movable hook 13B is stronger than that of the holder 12 and the long bolt 11, and the assembly set S is mechanically deformed before the fixed hook 13A and the movable hook 13B, thereby ensuring high safety.

  The dimensions of the holder 12 are, for example, 390 mm in length (full length), 22 mm in outer diameter, 18 mm in inner diameter, and 7 mm in groove width.

The fixed hook will be described with reference to FIG. 4 shows a fixing hook, FIG. 4A is a side view, FIG. 4B is a top view, and FIG. 4C is a partial sectional view as seen from the back of FIG. 4A.
As shown in FIG. 4A, the fixed hook 13A has a substantially C-shaped hook main body 13 in a side view having a hook portion, and a cylindrical shape that is combined with a side portion of the hook main body 13 and has an insertion hole formed therein. It consists of the body 14, and is formed with the molding by forging. The metal is carbon steel S45C. The forged molded body is firmer than a press-worked or cast product of a single plate (such as an iron plate) of the prior art.

  The hook body 13 includes a tip portion 13b extending a predetermined length from the top of the side body portion 13a on one side (left side in FIG. 4A) to the other side (right side in FIG. 4A), and similarly extending a predetermined length from the bottom portion 13c. Between the provided hook portion 13d, there is provided an insertion slot into which the link of the suspension chain C (see FIG. 7) is inserted, and a hook groove that communicates with the insertion slot and is engaged with the insertion slot. It is substantially C-shaped in side view.

  The distal end portion 13b extends from the side main body portion 13a with a predetermined width and length, and the distal end extends to the distal end of the hook portion 13d. The distal end portion 13b is formed with two pivot holes to which the pivot shaft portion of the stopper 15 is mounted. These pivot holes are formed at a predetermined interval, and the spring force of the abutment portion and the like is adjusted by this interval.

  The hook portion 13d extends from the bottom portion 13c extending from the side main body portion 13a toward the tip portion 13b with a predetermined width and length from the bottom portion 13c, and is erected on the tip portion side. It is almost the same. The bottom 13c is wider than the side body 13a. Due to the wide width, the hook portion 13d can be mechanically rigid. The hook portion 13d is erected from the bottom portion 13c so that the width thereof is substantially the same without being tapered. Since the wide bottom portion and the bottom portion are erected with substantially the same width, the hook strength of the hook portion 13d is increased. The width of the hook portion 13d is, for example, 8.0 mm, the length is 15.5 mm, and the width of the bottom portion is 16.5 mm.

Cylindrical body 14, the thickness and the internal of the insertion hole 14a in which the outer diameter is inserted into the hollow hole 12 ₀ of the holder 12 made of C-type pipe and the size of the bolt shaft 11b is inserted, a predetermined length And a thick cylindrical shape. The cylindrical body 14 is preferably slightly protruded from the lower end, that is, the bottom of the hook body 13. The projecting portion is assembled by projecting from the end of the holder 12.

  The cylindrical body has a length of 45 mm and an inner diameter of 13 mm. The size of the insertion hole 14a is slightly larger than the diameter of the bolt shaft 11b so that a slight gap is created when the bolt shaft is inserted, and the bolt shaft can freely rotate (idle). Have

The stopper 15 includes a contact portion that contacts the inner wall of the tip of the hook portion 11d of the hook body 11, a pair of extension pieces that extend from both ends of the contact portion for a predetermined length and face each other, and their extensions. It has a pair of pivot shafts whose ends are bent at one part, has a substantially hairpin shape in side view, and is formed by bending a single wire with a predetermined material and thickness Has been. Hook body 11
The chain link can be prevented from coming off by attaching the coming-off stopper 15.
A linear wire is a piano wire (SWP), The diameter is 1.5 mm, for example.

Next, the movable hook will be described with reference to FIG. 5 shows a movable hook, FIG. 5A is a side view, FIG. 5B is a top view, and FIG. 5C is a partial sectional view as seen from the back of FIG. 5A.
As shown in FIG. 5A, the movable hook 13B has a substantially C-shaped hook body 13 in a side view having a hook portion, and a cylindrical shape that is combined with a side portion of the hook body and has an insertion hole formed therein. It consists of the body 14, and is formed with the molding by forging.

This configuration is the same as the fixed hook 13A, a point on a part in the circumferential wall of the insertion hole 14a female thread 14 ₁ are formed is different. The length of the screw hole is determined by the relationship between the length of the cylindrical body and the traction force with the long bolt. That is, when the length of the cylindrical body is long, if it is formed on the entire inner peripheral wall of the insertion hole 14a, the movement with the long bolt is not smooth when the accuracy of the female screw is inferior. Unbearable. The length of the cylindrical body is, for example, 40 mm, and the length of the screw hole is, for example, 30 mm.

These fixed hook 13 </ b> A and movable hook 13 </ b> B are mounted such that both hook portions 13 d provided on both hooks face each other when mounted on the holder 12. Moreover, since both the fixed hook 13A and the movable hook 13B are formed of a forged molded body equivalent to carbon steel S45C, the strength is higher than that of the long bolt 11 and the holder 12 formed of ordinary steel.
The fixed hook 13A and the movable hook 13B are not limited to the above,
As the hook body and the stopper 15 or the like, those already known may be used.

With reference to FIGS. 1-5, the assembly of the tension / traction material length adjusting device 10 will be described.
First, the fixed hook 13A, the movable hook 13B, the retaining member 17 and the like are mounted on the holder 12 made of a C-shaped pipe.

Mounting the fixing hook 13A is a cylindrical body 14 at one end of the hollow hole 12 ₀ of the holder 12 of the fixing hook 13A, and insert projecting hook portion 13d of the hook body 13 from the clearance groove 12 _1, the end of the holder 12 Weld and fix to the part. The weld location is indicated by reference numeral 21 in FIG. By projecting the cylindrical body 14 during the assembly from one end of the bore 12 _0, when the long bolt 11 is mounted in the holder 12, the gap G ₀ between the end of the bolt head 11a and the holder 12 (See FIG. 1) is formed. The gap G ₀ prevents the bolt head 11 a from directly hitting the welded portion 21, so that no load is applied to the welded portion. It is preferable that at least one flat washer 16 is interposed between the bolt head 11a and the end of the holder 12.

The movable hook 13B is mounted so that the hook portion 13d of the movable hook 13B faces the hook portion 13d of the fixed hook 13A, and the cylindrical body 14 of the movable hook 13B is attached to the hollow hole 12 of the holder 12 made of a C-shaped pipe. from the other end of _0, inserting protruded hook portion 13d from the clearance groove 13 _1. In this state, the movable hook 13B is free to move longitudinally in the bore 12 within _0. Clearance grooves 12 ₁ serves the guide grooves when the movable hook 13B moves longitudinally. Thereafter, the long bolt 11 is attached. For this mounting, first, at least one flat washer 16 is mounted on the long bolt 11 and the tip 11d of the bolt shaft 11b is inserted into the insertion hole 14a of the fixing hook 13A fixed to the holder 12 and pushed. . This insertion / pushing can be smoothly pushed in because the diameter of the insertion hole 14a is larger than the diameter of the bolt shaft 11b.

Next, after rotating the movable hook 13B several times to the bolt shaft tip 11d and screwing it several times, when the bolt head 16a is turned clockwise, the male screw 11c at the tip of the bolt shaft 11b is moved to the movable hook 13B. screwed in the female screw 14 ₁ in the screw holes are screw coupled. Further, the bolt head 11a is rotated clockwise until the movable hook 13B is completely covered with the holder. Next, at least one flat washer 16 is attached to the tip end portion 11 d of the bolt shaft 11 d, and the retaining member 17 is fixed to the tip end portion of the long bolt 11. Through the above steps, the assembly of the chain length adjusting device 10 is completed.

  As shown in FIG. 6, the tension / traction material length adjusting device 10 includes a plurality of chains C1 and a plurality of chains / traction material length adjustment devices suspended on a structure (not shown). The two chains are connected to each other with a plurality of chains C2 attached to the steel pipes P1 to P3. It should be noted that a scaffolding plate is laid between each of the plurality of steel pipes P1 to P3 to form a working scaffold, but this scaffolding plate is omitted in FIG.

  Each tension / traction material length adjusting device 10 is connected to each of the chains C1 and C2, and then adjusts the length of each chain. This adjustment is performed by rotating the bolt head 11a of the tension / traction material length adjusting device 10. That is, in this rotation operation, a tool, for example, a manual tool (not shown) such as an electric tool or a ratchet is coupled to the bolt head 11a and rotated clockwise. When the bolt head 11a is rotated clockwise with this tool, the movable hook 13B rises in the direction toward the upper fixed hook 13A from the position approaching the lower (see FIG. 7A) flat washer 16 (see FIG. 7B). As the movable hook 13B rises, the lower chain C2 is pulled upward, and the length of the chain C2 connected to the movable hook 13B is adjusted.

  During the rotation operation of the bolt head portion 11a, the bolt head portion 11a contacts the protruding portion of the cylindrical body 14 of the fixed hook 13A and does not directly hit the hollow hole 12a, so that a load is applied to the welding point 17a. This prevents the welded part from being destroyed. Further, in the tension / traction material length adjusting device 10, when the bolt head portion 11a is rotated counterclockwise, the movable hook 13B is lowered downward. That is, by rotating the bolt head 11a clockwise or counterclockwise, the movable hook 13B moves up and down, and the length of the chain is adjusted.

The movable hook 13B is, in the holder 12, along the clearance groove 12 _1, that is being guided to move up and down, without movable hook 13B is rotated around the bolt shaft 11b, by one person working It can be done efficiently.

  By the way, the scaffolding is loaded with workers or equipment, but the capacity is over, or heavy equipment exceeding the limit is placed carelessly, or due to natural disasters (typhoons), etc. These may exceed the limit, and an excessive load may be applied to the scaffold. If such an excessive load is applied and the limit (allowable value) of the tension / traction material length adjustment device is exceeded, it may be damaged or broken, resulting in a serious accident. Therefore, it is necessary to take preventive measures to prevent such accidents.

  As a countermeasure against this, the tension / traction material length adjusting device 10 includes an assembly set S (see FIGS. 7 and 8) in which the holder 12 and the long bolt 11 are combined, a fixed hook 13A, and a movable hook 13B. When an excessive load is applied to the scaffold, the assembly set S is mechanically deformed before the fixed and movable hooks 13A and 13B, for example, bent in a substantially arcuate shape (see FIG. 8B). .

This bending is applied to the assembly set S when an excessive load exceeding the limit is applied to the scaffold, and this excessive load is transmitted to the movable hook 13A via the chain C2. That, _{L 1} the distance between the axes of the hook portion 13d and the bolt shaft 11b of the movable hook 13B, _{L 2} the distance between _{S O} points of the point on the axis S ₁ and assembly set S, the hook portion 13d and the _{S O} point When the distance _{L 3} between, _{L 3} becomes the square of the root of the square plus _{L 2} of _{L 1,} the moment applied to the _{S O} point assembly set S becomes _{L 3} × _FCosθ (see FIG. 8A).

Each hook portion 13d of the fixing hook 13A and the movable hook 13B projects from the clearance groove 12 ₁ of the holder 12, since the same direction, said moments same direction S _O point assembly set S, i.e. Each hook part 15b is hooked to the side. When this value exceeds the allowable value of the assembly set S, the assembly set S bends in a substantially arcuate shape. This bending state can be easily observed, and it can be determined that the tension / traction material length adjusting device exceeds the allowable value. Therefore, it is possible to prevent the occurrence of an accident by predicting damage to the adjusting device in advance by taking appropriate measures such as reducing excessive load and replacing the tension / traction material length adjusting device. .

  In order that the assembly set S combining the holder 12 and the long bolt 11 is deformed earlier than the fixed hook 13A and the movable hook 13B, these members are formed of different materials. That is, in this embodiment, the fixed hook 13A and the movable hook 13B are formed of a forged carbon steel body, and the holder 12 and the long bolt 11 (assembly set S) are formed of ordinary steel. Thereby, the strength of the forged molded body of the fixed hook 13A and the movable hook 13B becomes stronger than that of the holder 12 and the long bolt 11, and the assembly set S is mechanically deformed before the fixed hook 13A and the movable hook 13B.

  In addition, when an excessive load is applied, the assembly set S is mechanically deformed as described above. However, if an excessive load beyond this is applied, the bolt shaft of the long bolt 11 is exceeded. 11b can be expected to come off from the holder 12, but in the event of such an unexpected excessive load, even if the bolt shaft 11b comes off from the holder 12, the fixed hook 13A and movable Since the hook 13B remains firmly connected to the bolt shaft 11b of the long bolt 11, the chain is not detached and safety is ensured.

The tension / traction material length adjusting device 10 was tested.
Test conditions: Long bolt 11; length (full length) 408 mm, bolt head height 8 mm, bolt shaft length 400 mm, bolt shaft 11 b thickness (diameter) 12 mm, equivalent to ordinary steel SS400.
Holder 12: Length 390 mm, inner / outer diameter 22 mm, inner diameter 18 mm, gap groove width 7 mm, wall thickness 2.0 mm, equivalent to ordinary steel SS400.
Fixed hook 13A and movable hook 13B: An integrally formed body of a cylindrical body having a length of 45 mm, an inner diameter of 12 mm, a hook body 13 having a plate thickness of 6 mm, a bottom length of 42 mm, a height of 30 mm, and carbon steel S45C equivalent forging.
Chain: φ5mm (standard product) length 400mm (two).

-Load test result The graph shown in FIG.
The horizontal axis of the graph of FIG. 9 is the stroke of the device and the chain (mm), the vertical axis is the load load (kN), the curve of symbol a is the suspended state of FIG. 7A, and symbol b is the suspended state of FIG. result.
Curve a: load resistance until bending is 9.1 kN, maximum load is 21.5313 kN (hereinafter, chain breakage)
Curve b: The load capacity until bending is 11.0 kN, the maximum load is 21.0938 kN
(Hereafter, chain break)

・ Consideration: Normal use range (normative) 2.0kN
When this specified value (2.0 kN) was compared with the load resistance until bending including deformation of the chain, the result that the bending did not occur up to 4.5 times or 5.5 times was obtained.
The chain broke when the maximum load was exceeded, but the device bent but did not break.

  The tension / traction material length adjusting device 10 has the following relationship with the 3-step method of the international safety standard ISO / ECO guide 51.

A inherently safe design
This inherently safe design eliminates hazards as much as possible, or reduces risks as much as possible, and importantly means safety measures based on physical “principles”. Is defined.
The tension / traction material length adjusting device 10 has high durability and high safety from the viewpoint of the test result of the stroke versus load load (see FIG. 9). "Removing the risk or reducing the risk as much as possible". In other words, the legal use of this type of tension / traction material length adjusting device 10 is 2 kN, while the load resistance until bending including the deformation of the chain is 4.5 times and 5.5 times. The result is that it does not bend, which lasts until the chain breaks and is extremely safe.

B Protective devices
This means of protection is defined as the need to prevent expansion damage by a structure that prevents energy transmission for risks that cannot be reduced, and to be able to prevent or block energy transmission without fail.

  In the tension / traction material length adjusting device 10, the long bolt 11, the fixed and movable hooks 13 </ b> A and 13 </ b> B are mounted on the holder 12, and the tip 11 d of the bolt shaft 11 b is coupled by a flat washer 16 and a retaining member 17. Further, since the movable and movable hooks 13A and 13B are each provided with a detachment stop 15, the bolt shaft 11b does not jump out of the holder 12 even if an excessive load is applied to the device, and the chain is also detached. Can be prevented. Further, when an unexpected excessive load is applied, it is assumed that the bolt shaft 11b of the long bolt 11 comes off the holder 12 and jumps out, but in the unlikely event that such an unexpected excessive load is applied. In preparation, even if the bolt shaft 11b comes off the holder 12, the fixed hook 13A and the movable hook 13B remain firmly connected to the bolt shaft 11b of the long bolt 11, so that the chain does not come off and safety is ensured. It is secured.

  From the above, it is consistent with the above definition, “For risks that cannot be reduced, it is necessary to prevent expansion damage by a structure that prevents the transmission of energy, and to be able to prevent or block the transmission of energy without fail”.

C Notification to users (information for users)
This notification to the user is defined as notifying the user of usage and installation information for any remaining risks.
In the tension / traction material length adjusting device 10, when an excessive load is applied, the assembly set S including the holder and the long bolt bends in a substantially arcuate shape. This bending state can be easily observed, and it can be determined that the tension / traction material length adjusting device exceeds the allowable value. Therefore, it is possible to prevent the occurrence of an accident by predicting damage to the adjusting device in advance by taking appropriate measures such as reducing excessive load and replacing the tension / traction material length adjusting device. .
As described above, the tension / traction material length adjusting device 10 according to the embodiment of the present invention has safety conforming to international safety standards (3-step method of ISO / ECO guide 51). .

DESCRIPTION OF SYMBOLS 10 Stretching / traction material length adjustment apparatus 11 Long bolt 11a Bolt head 11b Bolt shaft 11c Male screw 11d Tip part 12 Holder 120 ₀ Hollow hole 12 ₁ Clearance groove 13A Fixed hook 13B Movable hook 13 Hook body 13d Hook part 14 Cylindrical body 14a Insertion hole 14 ₁ Female screw 15 Detachment stop 16 Flat washer 17 Retaining member S Assembly set

Claims (5)

A long bolt having a bolt head at one end, a bolt shaft having a predetermined length extending from the bolt head and having an external thread engraved on the outer peripheral surface, a hollow hole through which the bolt shaft is inserted, and the length of the outer peripheral wall A holder composed of a cover case having a gap groove in the vertical direction, and a fixed and movable hook attached to the long bolt and the holder;
The fixing hook includes a cylindrical body provided with an insertion hole through which the bolt shaft is inserted and fixed into the hollow hole of the holder, and a hook portion fixed to the cylindrical body and protruding from the gap groove. A hook body,
The movable hook is inserted into the hollow hole of the holder, and has a cylindrical body provided with a screw hole in which an internal thread is engraved with the male screw of the bolt shaft on the inner peripheral wall; A hook body provided with a hook portion fixed to the body and protruding from the gap groove,
The fixed hook is inserted into the holder from one end of the hollow hole so that the hook portion protrudes from the gap groove and is fixed to the end of the cover case, and the movable hook is inserted from the other end of the hollow hole. The hook portion protrudes from the gap groove and is movably inserted. The long bolt is inserted through the insertion hole of the fixed hook fixed to the holder, and is movably mounted on the holder. Screwed into the screw hole of the movable hook ,
The assembly set of the holder and the long bolt is mechanically deformed before the fixed and movable hooks when an excessive load is applied to at least one of the fixed and movable hooks. Stretching / traction material length adjustment device. 2. The tension / traction device according to claim 1, wherein the long bolt and the holder are made of plain steel, and the fixed and movable hooks are both made of a forged molded body made of carbon steel. Material length adjustment device. The long bolt is inserted into the holder, and a retaining member having a shape or a size different from that of the bolt head is attached to a tip of the long bolt . Tension / traction material length adjustment device. The tension / traction material length adjusting device according to claim 1, wherein a detachment stopper is attached to the fixed and movable hooks . The tension / traction material length adjusting device according to claim 1, wherein the long bolt has a shape in which the bolt head is coupled to a tool .

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