JP3955930B2 - Chain gauge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chain gauge for measuring the elongation of a load chain composed of a link chain.
[0002]
[Prior art]
A load chain composed of a link chain is widely used as a chain sling for hoisting machines such as chain blocks, lever hoists, and electric chain blocks and slinging.
[0003]
The load chain used for these is a strong chain heat-treated such as T-class (800 MPa) or V-class (1000 MPa), but the pitch spreads due to elongation or wear due to load over a long period of use. Therefore, in order to prevent a major trouble due to the breakage of the load chain, it is necessary to strictly check the elongation of the load chain, and it is also stipulated in the occupational safety and health regulations, ISO standards, and JIS standards. According to the standards, the limit of elongation is 5% for tempered chains and 3% for surface-hardened chains, and it is stipulated that chains that extend beyond this limit should not be used.
[0004]
Conventionally, for measuring the elongation of a load chain, a measuring instrument called a caliper 30 is used to measure a dimension between three links or five links (see FIG. 10), or a chain gauge 31 as shown in FIG. 11 is used. It was done.
[0005]
[Problems to be solved by the invention]
In general, a load chain having a wire diameter of 4 to 22 mm is frequently used, and the one having the most diameter is 6 to 16 mm. In the above-described conventional elongation measurement, a plurality of types of calipers 30 and chain gauges 31 must be prepared according to the load chain of each wire diameter, which is disadvantageous in terms of cost and cumbersome. In addition, the caliper 30 and the chain gauge 31 for a load chain having a large wire diameter are inevitably large in size, increasing the manufacturing cost and inconvenient to carry and handle.
[0006]
[Means for Solving the Problems]
Accordingly, an object of the present invention is to provide a small chain gauge that can solve the above-described problems in the conventional load chain elongation measurement and can be shared by load chains having a plurality of different wire diameters.
[0007]
That is, the present invention is a chain gauge for measuring the elongation of a load chain composed of a link chain, and a plurality of measuring portions having different outer diameters depending on the wire diameter of the load chain to be measured are gradually removed toward the tip. It is provided so that the diameter is small, and according to the wire diameter of the load chain, the corresponding measurement part is inserted between two links connected to one link in a perpendicular direction so that the distance between these two links is increased. It is characterized by measuring the elongation of the load chain by measuring. Each measurement unit may have a circular, square, or octagonal cross-sectional shape.
[0008]
According to a preferred aspect of the present invention, the plurality of measuring units are configured as a storage-type chain gauge that can be stored in a multi-stage nested manner in the storage case. In use, the corresponding measuring part protrudes from the storage case by moving the slide dial in accordance with the wire diameter of the load chain to be measured.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a chain gauge 2 according to an embodiment of the present invention, in which five cylindrical measuring parts 3 to 7 are provided at one end of a main body 8 which becomes a grip part during measurement work, and the other end of the main body 8 is provided. 9 is provided with a hole 10 for allowing an operator to wear the chain gauge 2 through a string or the like, and for using the chain gauge 2 for storage or the like.
[0010]
The cylindrical measuring units 3 to 7 have an outer diameter that gradually decreases from the main body 8 toward the tip, and are provided with markings 3a to 7a that indicate the wire diameter of the load chain 1 to be measured. In this embodiment, the cylindrical measuring unit 3 with the smallest diameter is used for measuring the elongation of a load chain with a diameter of 6 mm, and the measuring units 4 to 6 are used for measuring the elongation of a load chain with a diameter of 8 mm, 10 mm and 13 mm, respectively. The maximum diameter measuring portion is used for measuring the elongation of a load chain having a wire diameter of 16 mm.
[0011]
Referring to FIG. 2 showing an example of the load chain 1, the dimension L between two links connected to one link is obtained by subtracting twice the wire diameter of the load chain 1 from the pitch P. This dimension L increases as the pitch P increases due to elongation, wear, etc. due to load over a long period of use. That is, by measuring the dimension L, the elongation of the load chain 1 can be detected. More specifically, the outer diameter of each of the measuring portions 3 to 7 corresponding to the load chain wire diameter to be measured is set as a dimension L when the pitch P extends by 5% from the original specified dimension. Insert the appropriate measuring unit and measure. For example, for a load chain 1 having an 8 mm wire diameter, the measuring unit 4 is a corresponding measuring unit. However, when the measuring unit 4 cannot be inserted even if it is inserted between the links (FIG. 3), the elongation is not yet achieved. This means that the load chain 1 can be used because it has not reached 5%, and when the measuring part 3 passes through the gap L part (FIG. 4), the elongation is 5% or more. It is confirmed that the load chain 1 has reached the use limit.
[0012]
When measuring the elongation of the load chain 1, the links 13 and 14 located on both sides of the measurement link 12 and the inserted chain gauge 2 (measurement portions 3 to 7) are directly aligned with the center line as shown in FIG. It must be aligned on the line.
[0013]
Incidentally, the load chain 1 has a gap W in a direction perpendicular to the pitch (lateral direction) (FIG. 2), but the standardized load chain dimension gap W is larger than the link interval dimension L. Since the measurement parts 3 to 7 of this embodiment are cylindrical, the outer diameter of the measurement part is smaller than the lateral gap W. Accordingly, as shown in FIG. 6, the chain gauge 2 is off the center line in the lateral gap W and is close to one side, and the links 13 and 14 located on both sides of the measurement link 12 are semicircles of the measurement link 12. The arcuate inner surfaces 15 and 15 may be pushed to the other of the center lines. However, when the links 13 and 14 located on both sides with respect to the measurement link 12 are connected to the center line, the interference dimension between the chain gauge 2 and each side link 13 and 14 is X (FIG. 5). If the interference dimension between the chain gauge 2 and each of the side links 13 and 14 when Y is continuous from the center line is Y (FIG. 6), the inequality X <Y always holds. The condition in which the chain gauge 2 is most easily inserted is the case of FIG. 5, which is connected to both side links 13 and 14 at the center line, and each time the chain gauge 2 is inserted near the lateral gap W of the measurement link 12, Interference with the side link is increased, making insertion difficult. Therefore, even when the chain gauge 2 in which the measurement part is formed in a cylindrical shape is used, the state of FIG. 6 cannot occur in actual measurement, and accurate measurement can be performed in the state of FIG.
[0014]
7 and 8 show another embodiment of the chain gauge. The chain gauge 16 in FIG. 7 is formed with a square cross-section of each measuring portion, and the chain gauge 17 in FIG. 8 has an octagonal cross-section with each measuring portion. It is formed into a shape.
[0015]
FIG. 9 shows an embodiment configured as a retractable chain gauge 20, in which each measuring section 22 can be stored in a storage case 21 in a multistage nested manner. A slide groove 24 for guiding the slide dial 23 is formed on the side surface of the storage case 21. The slide dial 23 is screwed to the rear end portion of the slide body 25 stored in the storage case 21, and by tightening this screw, the slide dial 23 and the slide body 25 are held at arbitrary positions, and the screw is loosened. These can be moved. Since such a mechanism is well known in a cutter or the like, further detailed description is omitted.
[0016]
In this embodiment, as in the previous embodiment, there are provided measuring units 22a to 22e used for measuring the elongation of load chains with wire diameters of 6 mm, 8 mm, 10 mm, 13 mm and 16 mm. Although all of these measurement units may be configured in a multi-stage nested manner, in this embodiment, the 6 mm measurement unit 22 a and the 8 mm measurement unit 22 b are integrally provided, and the remaining three measurement units 22 c are provided. .About.22e are formed in a multistage nested manner. In this case, the slide body 25 is joined or connected to the 6 mm measuring unit 22 a or the 8 mm measuring unit 22 b, and the measuring units 22 a and 22 b are integrally formed by moving the slide dial 23 along the slide groove 22. Moving.
[0017]
On the surface of the storage case 21 near the slide groove 24, the wire diameter of the chain gauge to be measured is displayed, and FIG. 9 shows a state in the case of measuring a chain gauge having a wire diameter of 8 mm. At this time, a measuring part 22b for a wire diameter of 8 mm which is integral with a measuring part 22a for a wire diameter of 6 mm protrudes from the tip of the storage case 21, and this measuring part 22b is inserted between the links at right angles as described above. Can measure the spacing (elongation).
[0018]
When measuring the elongation of a chain gauge having a wire diameter of 10 mm, the slide dial 23 is slid leftward from the position shown in FIG. 9 and moved to a position on the wire diameter display of “10”. By this movement, the measurement parts 22a and 22b are integrally moved to the left, and the 10mm measurement part 22c protrudes from the tip of the storage case 21 due to the engagement with the annular protrusion 26 formed on the outer peripheral surface of the measurement part 22b. The elongation of a chain gauge having a wire diameter of 10 mm can be measured. At this time, the rear measurement units 22d and 22e connected to the measurement unit 22c in a multi-stage nested manner also move leftward together, but are still stored in the storage case 21. Then, by further moving the slide dial 23 to the left, it is possible to measure the elongation of the chain gauge having a wire diameter of 13 mm by the measuring unit 22d or to measure the elongation of the chain gauge having a wire diameter of 16 mm by the measuring unit 22e.
[0019]
When measuring the elongation of a chain gauge having a wire diameter of 6 mm, the slide dial 23 is slid rightward from the position shown in FIG. Thereby, the measurement part 22b is accommodated in the storage case 21, and the state where only the measurement part 22a protrudes from the front end of the storage case 21 is obtained. If the slide dial 23 is moved to the back end position of the slide groove 24, all the measurement parts 22a to 22e are stored in the storage case 21, which is convenient to carry.
[0020]
【The invention's effect】
According to the present invention, it is possible to measure the elongation of various types of load chains with different sizes (wire diameters) with one chain gauge, and it is not necessary to prepare a dedicated gauge for each size. There is also a great merit and it can bring about a very large effect in practical use.
[0021]
In particular, a retractable chain gauge that allows each storage section to be stored in a storage case in a multistage manner is compact and can be stored in a pocket of work clothes and is convenient for work. In addition, since each measuring unit is stored in the storage case when not in use, there is an effect that the measuring unit is hardly damaged or worn, the gauge life is extended, and stable measurement can be performed for a long time.
[Brief description of the drawings]
FIG. 1 is a front view (A) and a side view (B) of a chain gauge according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a load chain.
FIG. 3 is an explanatory diagram showing a procedure for measuring the elongation of a load chain performed using the chain gauge of FIG. 1, and showing that a load chain having a wire diameter of 8 mm is still usable.
FIG. 4 is an explanatory diagram showing a procedure for measuring the elongation of a load chain performed using the chain gauge of FIG. 1, and showing that a load chain having a wire diameter of 8 mm has reached the use limit.
FIG. 5 shows a normal state in which a cylindrical gauge measuring portion of a chain gauge is aligned with two side links connected to the measurement link in the measurement link on the center line, and the elongation of the load chain is measured. It is explanatory drawing which shows.
FIG. 6 is an explanatory view showing a hypothetical state in which a cylindrical measuring portion of a chain gauge is inserted into a measurement link off the center line.
FIG. 7 is a front view (A) and a side view (B) of a chain gauge according to another embodiment of the present invention.
FIG. 8 is a front view (A) and a side view (B) of a chain gauge according to still another embodiment of the present invention.
FIG. 9 is a front view showing a retractable chain gauge according to still another embodiment of the present invention.
FIG. 10 is an explanatory view showing a procedure for measuring a load chain elongation with a conventional caliper.
FIG. 11 is an explanatory diagram showing a procedure for measuring load chain elongation using a conventional dedicated gauge.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Load chain 2 Chain gauge 3-7 Cylindrical measuring part 3a-7a Wire diameter marking 12 of a to-be-measured load chain 12 Measurement links 13 and 14 Side link 15 Semi-circular inner surface 16 and 17 of a measurement link Chain gauge 20 Retractable chain gauge 21 Storage cases 22a to 22e Measuring unit 23 Slide dial 24 Slide groove 25 Slide body 26 Annular projection

Claims (3)

A chain gauge that measures the elongation of a load chain consisting of a link chain, and multiple measuring parts with different outer diameters depending on the wire diameter of the load chain to be measured so that the outer diameter gradually decreases toward the tip. The load is measured by inserting a measurement unit corresponding to the wire diameter of the load chain in a perpendicular direction between two links connected to one link and measuring the distance between these two links. A chain gauge characterized by measuring chain elongation. 2. The chain gauge according to claim 1, wherein each measuring portion has a circular, square, or octagonal cross-sectional shape. Multiple measuring units can be stored in a multi-stage nested manner in the storage case, and the corresponding measuring unit protrudes from the storage case by moving the slide dial according to the wire diameter of the load chain to be measured when in use. The chain gauge according to claim 1 or 2.

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