JP2001074617A - Limit gauge for inspecting hook - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inspecting implement capable of easily measuring an opening of a port of a hook at a job site, easily judging whether a hook exceeds a using limit or not, carrying, handling and manufacturing the hook by a non- skilled person. SOLUTION: The limit gauge 5 for inspecting a hook comprises a fundamental shape 1a of a shape of an outer periphery of the hook, and a shape for enveloping both the shapes of the same shape 1b as the fundamental shape moved in parallel with an opening direction of a port by a limit value of the opening of the port of the hook, superposed on the fundamental shape or the same shape as the fundamental shape outward rotated so as to open the port of the hook by a limit value of the opening of the port of the hook at the end of the hook at a lowermost point of the hook as a center, and superposed on the fundamental shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for inspecting a hook of a lifting device such as a chain block and a hoist.

[0002]

2. Description of the Related Art A hook of a lifting device such as a chain block or a hoist receives an extremely large load during lifting and is exposed to severe use conditions. A hook that has been used under severe conditions for a long time gradually deforms, eventually exceeding the use limit, and cannot withstand safe use even within the rated load of the lifting device. Therefore, the manufacturer of the lifting device determines the check of the shape of the hook as an important item of the periodic inspection manual. In particular, the deformation (increase) of the opening of the mouth 2 of the hook 1 shown in FIG. 3 is specified, and the opening size of the mouth is measured at each periodic inspection, and it is required that the hook whose size exceeds the limit value is not used thereafter.

[0003] However, the hook as a whole is shown in FIG.
As shown in the end view of the arrow A, it has a three-dimensional shape, and both sides of the opening of the mouth to be measured are also formed of three-dimensional curved surfaces. It is difficult to determine whether to measure between two points, and it is difficult to accurately detect and determine a dimensional change of only about 5% as compared with a new one. In addition, the hook 4 has a metal fitting 4 for preventing the sling wire from coming off, which hinders further measurement.

Since the measurement is difficult and the judgment is difficult, even though the importance of checking the deformation of the opening of the hook mouth is well understood, it is difficult at present to manage according to the manual on site.

[0005]

SUMMARY OF THE INVENTION The opening of a hook can be easily measured on site, and even an unskilled person can easily judge whether or not the hook has exceeded a use limit, and can carry it.
An inspection instrument that is easy to handle and manufacture is provided.

[0006]

According to the present invention, the shape of the outer periphery of the hook is set as the basic shape, and the same shape as the basic shape is moved in parallel in the opening direction of the hook by the limit value of the opening of the hook to overlap the basic shape. In addition, it is a limit gauge for hook inspection having a shape enclosing both shapes.

[0007] In the periodic inspection, the manufacturer of the lifting device that the manufacturer of the hoisting device needs to measure and manage is the inner dimension of the hook mouth. However, it is difficult to directly measure this, so the inner method must be used instead. The measurement is made indirectly based on the change in the outer dimension. In general, the load applied to the hook is a downward load due to the suspended load, so the deformation due to the fatigue of the hook occurs so as to unwind the hook, that is, to open its mouth, and in this case, the hook is perpendicular to the bending axis. It is considered that the shape of each cross section hardly changes. Therefore, when the internal dimension of the hook mouth is increased by the limit value, the outer peripheral dimension around the hook mouth should be approximately increased by the limit value. Based on the above assumption, the idea is to create a limit gauge for the outer periphery of the hook and use it to manage the opening of the hook mouth. Therefore, when a situation that does not meet the above assumption occurs, for example, when the shape of the hook is locally deformed, or when the hook is deformed to twist, etc., without relying on this limit gauge, Needless to say, it must be determined separately according to the inspection manual.

First, based on the outer shape of the hook, that is, the outer shape, not the inner side of the hook on which the hanging wire is hung, the basic shape is the same as the basic shape, which corresponds to the limit value of the opening of the hook. It is moved parallel to the direction in which the mouth opens, and superimposed on the basic shape to create a mold that envelopes both shapes. At this time, this mold needs at least half the thickness of the hook to be used as a limit gauge. At the time of periodic inspection, a hook is fitted to the limit gauge, and it is determined that the hook can be used if it enters the gauge and that the hook cannot be used if it does not.

Further, the present invention is based on the basic shape of the outer periphery of the hook, and the same shape as the basic shape is obtained by setting the tip of the hook centering on the lowermost point of the hook by the amount of the hook opening limit. This is a limit gauge for hook inspection having a shape that is rotated outward and overlapped with the basic shape so that the mouth is open, and that has a shape that envelopes both shapes.

The reason that the hook is deformed so that the mouth is opened is a result of the deformation from the root portion of the hook to the vicinity of the lowest point of the hook where the load of the suspended load is directly suspended, so that the hook is bent. From the bottom point of the hook to the tip of the hook, the mouth of the hook should spread with little change in shape. Therefore, it is considered that the movement in which the tip of the hook is rotated outward about the lowest point is closer to the actual deformation than the above-described case of the parallel movement, and the opening of the hook is more accurately managed. We can expect it to be possible.

By employing the present invention, it is possible to easily measure the opening of the hook at the site, and even an unskilled person can easily determine whether or not the opening of the hook exceeds the use limit. The effect is obtained.

Further, the present invention is the limit gauge for hook inspection according to claim 1 or 2, wherein the range to be manufactured as the limit gauge is limited to a portion around the mouth of the hook.

Since only the mouth portion of the hook needs to be managed, even if the limit gauge is made only in the vicinity of that portion, if the limit gauge can be used by applying it to an appropriate place on the hook, it is not applicable. The effect is the same. On the other hand, in the mouth portion of the hook, as shown in FIG. 6, there is a place where the outer periphery of the hook is most constricted at the base of the hook, so that the place where the limit gauge is applied is clear, while the tip end of the hook is Because the position of the limit gauge applied at the position of the limit gauge is regulated, even if the limit gauge is made only near the mouth, it may be misplaced or misplaced, and the measurement may be incorrect. There is no danger of doing. To use the limit gauge, place one end on the tip of the hook and push the other end in the direction that it fits naturally at the base of the hook. It can be used if entered, and cannot be used if not. On the other hand, by limiting only the portion around the mouth of the hook, the limit gauge can be made more easily, and it can be made smaller and lighter, so that it is easier to carry and handle.

By adopting the present invention, in addition to the effects described above, an effect that manufacturing, carrying, and handling are further facilitated is obtained.

Further, according to the present invention, a portion corresponding to an outer periphery of a hook is separated, and the two portions are connected so that a relative distance or a relative distance and a relative angle can be adjusted. It is.

Since the hooks are generally made by forging, even if the models are mass-produced, each shape is slightly different. Moreover, the outer circumference of the hook that this gauge targets is
It is imagined that its dimensions are not strictly controlled during production, especially since it is not the inside of the mouth of the hook which requires strict control. Therefore, as long as the outer circumference of the hook is to be measured, a limit gauge must be manufactured by any of the above-described methods by taking a mold for each hook, which is not easy. Therefore, in the case of the same type of hook, it is presumed that there is not much difference in the shape of the curved surface on the outer periphery of the portion around the mouth. To make a limit gauge that can be applied to all hooks.

First, a limit gauge limited to a portion around the mouth of the hook with respect to one hook is prepared. Since the outer periphery of the hook is located at two places on the left and right, the two parts are separated to form a limit gauge in which the relative distance or the relative distance and the relative angle can be adjusted.
If a plurality of the hooks are manufactured and the relative distance and the relative angle are adjusted according to each hook, a limit gauge corresponding to each of the hooks can be easily formed. Whether only the relative distance can be adjusted or both the relative distance and the relative angle can be adjusted can be considered as the former if the variation in the outer peripheral shape of the hook is small, and the latter if the variation is large. In addition, it is only necessary that the shape of the curved surface of the outer periphery of the portion around the mouth of the hook is enough to function as a limit gauge, so that as long as this condition is satisfied, the size of the hook and the hook Even if the lifting equipment used has different rated capacities,
This limit gauge is compatible.

By employing the present invention, in addition to the effects described above, an effect is obtained that a large number of limit gauges corresponding to a large number of hooks can be easily manufactured.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to such an embodiment, and it goes without saying that various changes may be made to the specific structure within the scope of the present invention.

FIG. 1 is a plan view of an embodiment of the present invention. The manufacturer defines the shape 1a of the outer peripheral portion of the hook 1 indicated by a solid line, that is, the line from the starting point 1d of the left shoulder of the hook 1 in the figure to the end point 1e of the tip of the hook through the outside. The shape 1b translated in the direction of the opening direction B of the hook opening by the limit value 3 of the opening of the mouth 2 is overlapped. In addition, in these explanatory drawings, the shape including the inner part of the hook is illustrated for easy understanding. However, as will be understood from the following description, the inner part is directly used for preparing the limit gauge. Not relevant. A mold 5 having a shape enclosing the two shapes 1a and 1b is prepared and used as a limit gauge.

FIG. 2 is a sectional end view of the hook 1 and the limit gauge 5 taken along the line CC of FIG. The most common cross-sectional shape of the limit gauge is a case where the limit gauge is formed of a curved surface along the shape of a hook as shown in FIG. 5A and a case where a flat plate is used as a bottom as shown in FIG. Let's be.
In any case, the depth must be at least half of the thickness of the hook so that a portion in contact with the outer peripheral line of the hook serving as a limit gauge can be sufficiently obtained. In the case of FIG. It is desirable to provide a support 6 having an appropriate shape to support the tip of the hook, which is gradually reduced in thickness so that the hook can be received flat. These contents are the same in other embodiments described below.

FIG. 3 is a plan view of another embodiment of the present invention. Based on the shape 1a of the outer peripheral portion of the hook 1 indicated by the solid line as a basic shape, the same shape is applied to the hook at the lowest point D of the hook, and the hook is moved by the limit value 3 of the opening of the mouth determined by the manufacturer. Is overlaid with the shape 1c rotated outward so that the mouth 2 is opened. These two shapes 1a and 1c
A mold 7 having a shape enclosing is used, and this is used as a limit gauge.

In each of the above embodiments, the portion in contact with the outer peripheral line of the hook constitutes a continuous wall in any case, but the shape of the envelope enclosing both shapes 1a and 1b or 1a and 1c. Any shape may be used, and discontinuous walls may be erected at appropriate intervals along the envelope, or bar-shaped pieces or the like may be erected at appropriate intervals to form a portion in contact with the outer peripheral line.

By adopting any of the above-described embodiments, in addition to the above-described effects, it is possible to reduce the cost and cost by punching from a thin plate, combining a plate, or combining a plate and a bar. The advantage is that it can be easily manufactured.

FIG. 4 is an explanatory diagram of another embodiment of the present invention. The embodiment shown in FIG.
In contrast to the shape enclosing the entirety of the hook b, in the present embodiment, as shown in FIG. is there. Even if the production part is limited in this way, the left part of the limit gauge 8 is formed by the constricted part 8a of the shoulder of the hook.
Further, the right side portion of the limit gauge 8 is firmly positioned by the corresponding portion 8b at the tip of the hook, and its function is not impaired. The same applies to the case where the limit gauge is manufactured by limiting the portion around the mouth of the hook based on FIG. FIG. 2B shows the bird's-eye view.

FIG. 5 is an explanatory diagram of still another embodiment of the present invention. Parts 11 and 12 that hit the outer circumference of the hook
Has bottom plates 13 and 14, respectively.
The bottom plate 14 has a guide plate 17 into which the slide portion 16 fits snugly and a hole 19 through which a fixing bolt 18 penetrates. A large number of limit gauges of this configuration are made on the basis of one hook and tightened and fixed with fixing bolts 18 and nuts 20 according to each hook of the same type, so that each hook can be easily attached to many hooks. One corresponding limit gauge can be made. In this embodiment, only the relative distance between the portions 11 and 12 that are the outer periphery of the hook is adjustable. However, the guide plate 17 is not provided, or the gap between the guide plate 17 and the slide portion 16 is opened. Not only the relative distance but also the relative angle can be adjusted. Also, since the relative distance and relative angle once fixed need to be constant during the service life of the hook, an appropriate detent must be applied to the fixing bolt and nut, and not the bolt and nut. It is desirable to adopt a fixing method of integrating the bottom plates 13 and 14 by welding or the like.

[0027]

According to the present invention, it is possible to easily measure the opening of the hook at the site, and even an unskilled person can easily determine whether or not the opening of the hook exceeds the use limit. Easy to carry and handle,
An effect is obtained in that a large number of gauges corresponding to a large number of hooks of the same type can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is an end view of a section taken along line CC of FIG. 1;

FIG. 3 is a plan view of another embodiment of the present invention.

4A and 4B are a plan view and a bird's-eye view of an embodiment of the present invention in which a limit gauge is created limited to a portion around a hook mouth.

FIG. 5 is a bird's-eye view and a cross-sectional view of an embodiment in which a relative distance of a portion corresponding to an outer periphery of a hook is adjustable.

FIG. 6 is a front view and a sectional view of a hook.

[Explanation of symbols]

 Reference Signs List 1 hook 1a shape of outer peripheral portion of hook (basic shape) 1b shape of parallel translation of basic shape 1c shape of basic shape rotated in opening direction of hook mouth 1d origin of left shoulder of basic type hook 1e end point of tip of basic type hook 2 hook 3 Limit value of the opening of the hook opening 4 Metal fitting for preventing the slinging wire from coming off 5 Limit gauge (type) 5a, 5b Cross-sectional shape of the limit gauge 6 Support 7 Limit gauge (type) 8 Partial limit gauge 8a 8b Front end corresponding portion 11, 12 A portion corresponding to outer periphery of hook 13, 14 Bottom plate 15 Long hole 16 Slide portion 17 Guide plate 18 Fixing bolt 19 Hole 20 Fixing nut B Hook opening direction D Lowermost point of hook

Claims (4)

[Claims] 1. The outer shape of a hook is a basic shape, and the same shape as the basic shape is translated in the direction of opening of the hook by a limit value of the opening of the hook to overlap the basic shape, and both shapes are enveloped. A hook inspection limit gauge with a shape. 2. The basic shape of the outer periphery of the hook is the same as that of the basic shape, and the tip of the hook is opened at the lowermost point of the hook as the center, and the mouth of the hook is opened by the limit value of the opening of the hook. A hook inspection limit gauge that has a shape that rotates outward and overlaps the basic shape, and envelopes both shapes. 3. The limit gauge for hook inspection according to claim 1, wherein a range to be manufactured as a gauge is limited to a portion around a mouth of the hook. 4. The hook inspection limit gauge according to claim 3, wherein a portion corresponding to an outer periphery of the hook is separated, and the two portions are connected so that a relative distance or a relative distance and a relative angle can be adjusted.