JP4362217B2 - Tightening confirmation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tightening confirmation method using a tightening tool such as a spanner or a monkey spanner used when tightening bolts or nuts.
[0002]
[Prior art]
Bolt tightening is used for assembling all structures, and high-strength bolts are actively used in recent construction machines and railway vehicles. The performance of the bolt joint in tightening the high-tensile bolt depends on the quality of the axial force (tightening torque) management of the bolt. In general, since the axial force of the bolt and the tightening torque are directly proportional, a torque control method for tightening the bolt with a constant torque in order to obtain a constant bolt axial force is often employed.
[0003]
In this torque control method, after tightening the bolts, the torque value is read with a torque wrench to detect whether the specified torque has been introduced, and those that pass are marked with paint etc. The axial force is managed. However, since paint is easy to peel off and it is easy to dry, it is very difficult to manage, and when the number of bolts is large, a lot of man-hours are required. The current situation is not. For this reason, a tightening tool and a tightening confirmation method that allow easy management of the tightening torque visually have been desired, and several proposals have been made so far.
[0004]
For example, according to what is disclosed in Japanese Examined Patent Publication No. 54-41279, as shown in FIGS. 17 and 18, the inside of a polygonal fitting hole 31 to be fitted to a polygonal surface 21 of a nut 20 or a bolt head. The polygonal surface 21 of the nut 20 or the bolt head is fitted into the fitting hole 31 of the fastener 30 having the protrusion 33 formed on the peripheral surface 32, and the fastener 30 is rotated in the screw direction. The protrusion 33 is tightened while being pressed against the polygonal surface 21 of the nut 20 or the bolt head, and a protrusion indentation 22 having a depth or length proportional to the tightening force is left on the polygonal surface 21. Yes.
[0005]
Further, for example, according to what is disclosed in Japanese Utility Model Laid-Open No. 57-193363, as shown in FIG. 19, a nut or bolt head to be fastened 40 and a fitting surface 42 of a spanner 41 are provided. A cemented carbide tip 43 that protrudes into the generated gap is provided so that the protrusion indentation 44 remains on the tightened body 40 when the tightening is completed.
[0006]
[Problems to be solved by the invention]
However, in the technique disclosed in the above Japanese Patent Publication No. 54-41279, since the protrusion 33 protrudes from the inner peripheral surface 32 of the fitting hole 31 of the fastener 30, the protrusion 33 is easy to stick out by use. , Gaps and backlash are likely to increase. Further, since the fitting hole 31 has the projection 33, the fitting may not be possible due to variations in the dimensions of the nut 20 and the bolt head. For this reason, if the fitting hole 31 is provided with a margin, there is a problem that clearance and play are likely to increase. In addition, since the protrusions 33 are provided on the entire circumference of the inner peripheral surface 32 of the fitting hole 31, there is a problem that confirmation cannot be made when the same nut 20 or bolt head is retightened.
[0007]
In the technique disclosed in Japanese Utility Model Laid-Open No. 57-193363, the carbide tip 43 protrudes from the fitting surface 42 of the spanner 41, so that the carbide tip 43 is easy to stick with use. Therefore, there are problems that gaps and backlash are likely to be large, and that the workability is not good because the protrusions may not be able to fit due to variations in the dimensions of the nut or bolt head. In addition, since the projection indentation 44 by the cemented carbide tip 43 has a cone shape, there is a problem that visual confirmation is difficult.
[0008]
The present invention pays attention to the above-mentioned conventional problems, and when tightening the tightening member with a specified torque, an indentation that is easily visible remains on the pressing portion of the tightening member, and due to the variation in the size of the tightening member. It is an object of the present invention to provide a tightening confirmation method that can be used for a long period of time without causing poor fitting and without causing gaps or play due to looseness in the fitting portion.
[0009]
[Means for solving the problem, operation, and effect]
The first invention of the confirmation method tightening according to the present invention, at least any one side of the pair of pressing surfaces facing the tightening tool such as spanner or Monkisupana a plurality of grooves of fasteners used during First Press tightening The pressing portion of the tightened member having a pressing portion of two parallel parallel surfaces, such as a bolt or a nut, using a tightening tool having a plurality of grooves separated from each other by a predetermined distance and having a different groove pattern, Confirm the retightening torque of the tightened member by re-tightening with the specified torque while pressing with the pair of pressing surfaces of the tightening tool, and visually confirming the indentation remaining on the pressed portion of the tightened member. It is characterized by.
[0010]
According to the first invention of the tightening confirmation method, since the indentation of the groove pattern different from the indentation at the time of the first tightening remaining in the pressing portion of the tightened member such as a bolt or a nut can be easily recognized, The tightening torque of the member to be tightened during tightening can be easily confirmed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings. In the following embodiment, a spanner will be described as an example. A first embodiment will be described with reference to FIGS. First, the structure of the first embodiment will be described with reference to FIGS. 1 is a top view of the spanner 1 according to the present embodiment, FIG. 2 is a Z view of FIG. 1, FIG. 3 is a Y view of FIG. 1, and FIG. 4 is a cross-sectional view taken along line AA of FIG. . As shown in FIG. 1, a plurality of substantially V-shaped grooves 5, 6 are provided at predetermined positions of the pressing surfaces 2, 3 facing the spanner 1.
[0012]
As shown in FIG. 2, the groove 5 is provided between a predetermined distance c from a position separated from the opening tip 2a of the spanner 1 by a predetermined distance c from the opening tip 2a, and is predetermined with respect to the tightening axial direction s. It is inclined by an angle α. And as shown in FIG. 3, the groove | channel 6 is provided in the predetermined width d from the opening front-end | tip part 3a of the spanner 1 to the corner part 4, and inclines only the predetermined angle (alpha) with respect to the fastening axial direction s. .
[0013]
As shown in FIG. 4, the grooves 5 and 6 are substantially V-shaped, and a plurality of grooves are arranged so as to have a pressing flat surface having a predetermined width e between adjacent grooves. Further, the pressing surfaces 2 and 3 and the grooves 5 and 6 of the spanner 1 are subjected to surface hardening treatment such as titanium coating and induction hardening, so that the hardness is high.
[0014]
Next, operations and effects of the first embodiment will be described with reference to FIGS. FIG. 5 is an explanatory diagram of a tightening state by the spanner 1, and FIG. 6 is a diagram illustrating a relationship between the tightening torque T and the indentation depth f. As shown in FIG. 5, the head two surfaces 12 and 13 of the bolt 11 are inserted between the pressing surfaces 2 and 3 of the spanner 1 facing each other, and then the spanner 1 is rotated in the P direction shown in the drawing to obtain a predetermined torque T When the bolts are tightened, pressing forces F (F = T / L) act on the points g and h of the head two surfaces 12 and 13 of the bolt 11 (positions of the width d facing the grooves 5 and 6 of the spanner 1). . Then, as shown in FIG. 6, indentations having a depth f corresponding to the tightening torque T are formed at the points g and h of the head of the bolt 11. Here, since the grooves 5 and 6 have pressing flat surfaces having a predetermined width e between adjacent grooves as shown in FIG. 4, when the tightening torque T is smaller than the specified torque Tc, The indentation depth f is shallow (therefore, the indentation is not conspicuous), and when the specified torque Tc is approached, the indentation depth f becomes abruptly deep, and when the specified torque Tc is reached, the indentation depth f becomes the predetermined depth fc. The relationship between the magnitude of the tightening torque T and the indentation depth f is set by the relationship between the hardness of the member to be tightened, the hardness of the pressing surfaces 2 and 3 and the grooves 5 and 6 and the width e of the pressing flat surface. can do.
[0015]
FIGS. 7 and 8 are views showing indentations 14 and 15 remaining on the two opposite head surfaces 12 and 13 of the bolt 11 after completion of tightening, respectively, and FIG. 9 is a cross-sectional view taken along the line BB in FIG. is there. As shown in FIGS. 7 to 9, when the bolt 11 is tightened with the specified torque Tc or more as described above, the g and h points on the head two surfaces 12 and 13 of the bolt 11 can be easily visually checked. Indentations 14 and 15 of fc are imprinted respectively.
[0016]
Accordingly, since the operator or the manager can visually confirm that the bolt 11 has been tightened with the specified torque Tc by visually observing the indentations 14 and 15, it is very easy to visually confirm the torque management and tightening completion. Easy to. As shown in FIG. 6, when the tightening torque T is equal to or less than the specified torque Tc, the indentation depth f is extremely smaller than the predetermined depth fc. There is no misunderstanding that tightening at or below the torque Tc has been completed at the specified torque Tc.
[0017]
The pressing surfaces 2 and 3 including the grooves 5 and 6 of the spanner 1 have a hardness of a predetermined value or more by a surface hardening process such as titanium coating and induction hardening. The grooves 5 and 6 have a pressing flat surface having a predetermined width e between adjacent grooves, and receive a pressing load on the pressing flat surface when tightening. As a result, the pressing surface of the fastening tool is unlikely to become sticky, and gaps and backlash are unlikely to occur, so that it can be used for a long time. Further, since the grooves 5 and 6 do not protrude from the pressing surfaces 2 and 3, the workability can be improved without causing poor fitting with nuts and bolts. Further, as shown in FIGS. 2 and 3, since the grooves 5 and 6 have a diagonal pattern, electric discharge machining is possible, and machining is very easy.
[0018]
Next, a second embodiment will be described with reference to FIGS. FIG. 10 is an explanatory diagram of a tightened state by the spanner 1A in the present embodiment. 11 is an X view of FIG. 10, and FIG. 12 is a W view of FIG. In the second embodiment, as shown in FIGS. 11 and 12, the patterns of the grooves 5 and 6 in the first embodiment are changed from diagonal lines to meshes, and grooves 5A and 6A are provided. Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0019]
Next, the operation and effect of the second embodiment will be described with reference to FIGS. FIG. 13 is a diagram illustrating the appearance of the indentations 14A and 14A remaining on the two opposite head surfaces 12 and 13 of the bolt 11 after completion of tightening. As shown in FIG. 10, the head two surfaces 12 and 13 of the bolt 11 are inserted between the pressing surfaces 2 and 3 of the spanner 1 facing each other, and then the spanner 1A is rotated in the P direction shown in the drawing to When tightened with the prescribed torque Tc, as shown in FIG. 13, mesh-like indentations 14A and 14A are formed on the head two surfaces 12 and 13 of the bolt 11 by the grooves 5A and 6A.
[0020]
Therefore, for example, when the bolt 11 is loosened for some reason after the bolt 11 is tightened with the specified torque Tc by the spanner 1 in the first embodiment at the first tightening, the bolt is tightened by the spanner 1A of the second embodiment at the time of retightening. When 11 is tightened with a specified torque Tc, mesh-like indentations 14A and 14A are additionally stamped on the head two surfaces 12 and 13 of the bolt 11. Since the indentations 14A and 14A have different patterns from the indentations 14 and 15 in the first embodiment, the completion of re-tightening can be easily confirmed by visually inspecting the indentations 14A and 14A.
[0021]
In the first and second embodiments, the patterns of the grooves 5, 6, 5A, and 6A are diagonal lines and meshes. However, the present invention is not limited to this. For example, as shown in FIGS. Alternatively, spanners 1B and 1C having grid-like grooves 5B and 5C may be used. In addition, when re-tightening, a wrench having a groove pattern different from that at the time of initial tightening may be used, so it is possible to easily confirm completion of re-tightening by combining various groove patterns. In addition, as shown in FIG. 16, the same spanner 1D is formed with a groove 5A for tightening and a groove 7 having a groove pattern for loosening that is different from the pattern of the groove 5A, and this spanner 1D is also used for loosening. By using it together, it is very convenient because it can be easily confirmed that it has already been loosened at the time of re-tightening.
[0022]
As described above, according to the tightening tool and the tightening confirmation method according to the present invention, when a tightening member such as a bolt or a nut is tightened with a specified torque, an indentation groove is formed on the opposing pressing surface of the tightening member. Can be engraved within a predetermined area. In addition, the indentation grooves are formed in various patterns such as diagonal lines or meshes, and when indented with a tightening torque higher than the specified torque, an indentation of a predetermined depth is reliably left, so that the indentation is reflected by irregularly reflecting light. It is very easy to visually check. Therefore, the tightening confirmation can be easily and surely performed by visually observing the indentation.
[0023]
In addition, for example, a fastener with a diagonal pattern groove is used at the first tightening, and a retightening tool with a mesh pattern groove different from that at the first tightening is used. It is easy to visually confirm the difference between the indentation of the oblique line pattern at the time of attaching and the indentation of the mesh pattern at the time of retightening. Therefore, by visually observing the indentations of the mesh pattern, it is possible to easily and surely confirm the tightening at the time of retightening.
[0024]
Furthermore, since the pressing surface including the groove portion of the fastener is subjected to surface hardening treatment such as titanium coating or induction hardening, the hardness is high, and the groove is pressed flat with a predetermined width with respect to the adjacent groove. Since it has a surface and does not protrude from the pressing surface, it can be used for a long time without causing settling or poor fitting.
[Brief description of the drawings]
FIG. 1 is a top view of a spanner according to a first embodiment of the present invention.
FIG. 2 is a Z view of FIG.
FIG. 3 is a Y view of FIG. 1;
4 is a cross-sectional view taken along the line AA in FIG.
FIG. 5 is an explanatory diagram of a tightening state by a spanner in the first embodiment.
FIG. 6 is a diagram showing the relationship between tightening torque and indentation depth.
FIG. 7 is a diagram showing a first indentation remaining on the bolt head after completion of tightening.
FIG. 8 is a diagram showing a second indentation remaining on the bolt head after completion of tightening.
9 is a sectional view taken along line BB in FIG.
FIG. 10 is an explanatory diagram of a tightening state by a spanner in the second embodiment.
11 is an X view of FIG.
12 is a view as viewed from W in FIG.
FIG. 13 is a diagram showing indentations remaining on the bolt head after completion of tightening in the second embodiment.
FIG. 14 is a view showing a spanner having a groove having another groove pattern.
FIG. 15 is a view showing a spanner having grooves having other groove patterns.
FIG. 16 is a view showing a spanner having both groove patterns for tightening and loosening.
FIG. 17 is a first example of a conventional fastener.
FIG. 18 is an explanatory view of an indentation by a conventional first example fastener.
FIG. 19 is a second example of a conventional fastener.
[Explanation of symbols]
1, 1A, 1B, 1C, 1D ... Spanner, 2, 3 ... Pressing surface, 2a, 3a ... Tip, 4 ... Corner, 5, 6 ... Groove, 5A, 6A ... groove, 7 ... groove for loosening, 11 ... bolt, 12,13 ... two heads, 14,15 ... indentation, 14A ... indentation.

Claims (1)

  A plurality of grooves (5, 6) of the fastening tool used at the time of the first fastening are provided on at least one side of a pair of opposing pressing surfaces (2, 3) of a fastening tool such as a spanner (1A) or a Monki spanner. Using the fasteners provided with a plurality of grooves (5A, 6A) that are different in groove pattern and separated from each other by a predetermined distance, the pressing parts (12, 13) on the parallel two surfaces facing each other such as bolts (11) or nuts Retightening with a specified torque (Tc) while pressing the pressing portions (12, 13) of the tightened member (11) having a pair of pressing surfaces (2, 3) of the fastener, A tightening confirmation method characterized by confirming the retightening torque of the member to be tightened (11) by visually recognizing the indentation (14A) remaining on the pressing part (12, 13) of the member (11). .

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