Metallic pipe bending gauge jig and metallic pipe bending method using the same

Abstract

To provide a metallic pipe bending gauge jig and a metallic pipe bending method using the same, which can easily and accurately mark a target position necessary for bending without dependence on an operator's experience or skill.SOLUTION: A metallic pipe bending gauge jig (10, 50) comprises: a mounting part (11A, 11B, 51) detachably fitted to the outer periphery of a metallic pipe; and a long measure (12, 52) connected to the mounting part and positioned along the side surface of the metallic pipe in parallel with the center axis of the metallic pipe. On the surface of the measure (12, 52), a scale line group (20, 60, 70) indicating a plurality of bending target positions including a bending size position, a bending start position, and a bending end position is provided along the longitudinal side.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a metal pipe bending gauge jig that can efficiently and accurately apply a mark used when, for example, a wire pipe is bent by a vendor to a target metal pipe, and contributes to improving the efficiency of the entire bending process, and a metal pipe bending method using this jig.

Background Art

[0002] Electrical wiring is essential in the construction of electrical equipment in various buildings, and wires and cables are protected by pipes called wire pipes. Usually, wires and cables are passed through the previously laid pipes later. Therefore, the wire pipe is laid on a predetermined electrical wiring path, and bending is performed on the portion corresponding to the wiring design path.

[0003] In many cases, the bending of the wire pipe is carried out by an operator 300 using a hickey-type manual bender 200 at the construction site as shown in FIG. 14. The manual bender 200 has a groove-shaped upwardly convex curved portion 211 formed in a head portion 210 attached to the tip of a bender support column 220, and a locking portion 213 provided above the curved portion 211.

[0004] In such a manual bender 200, first, one end side of the wire pipe 100 is inserted between the curved portion 211 and the locking portion 213 to be in a hooked state, and then the operator 300 holds the bender support column 220, stands on the floor or ground, presses it while fixing the head portion 210, and holds the other end side of the wire pipe 100 and pushes it down along the groove of the curved portion 211, thereby bending the wire pipe 100 based on the lever principle with the top portion 212 of the curved portion 211 as the point of action.

[0005] When the wire pipe 100 is bent by the manual bender 200 as described above, the wire pipe 100 is repeatedly pushed and bent little by little while being fed and moved relative to the head portion 210 so that the pipe cross-section is not crushed and deformed.

[0006] In the case of metal piping, since the inner radius of the bent portion is specified to be 6 times or more the inner diameter of the pipe in the ordinance (Article 56) that stipulates the technical standards for electrical equipment, other conditions for actually bending the wire pipe are set based on this.

[0007] For example, when performing a 90-degree bending process on a non-threaded wire pipe with an outer diameter D = 19.1 mm and an inner diameter d = 16.7 mm, called E19, the inner bending radius R of the wire pipe must be d×6 = 100.2 (mm) or more. Here, if the desired radius R in the piping design is 120 mm, since this is sufficiently larger than the specified minimum value of 100.2 mm, it is adopted without problems. When the radius R is 120 mm in this way, each design required for the bending process is set as follows.

[0008] First, the bending radius r of the central axis of the wire pipe is the distance obtained by adding the distance of 19.1 / 2 = 9.55 (mm) from the inner bending radius position to the central axis of the outer diameter D of the wire pipe. Therefore, r = 120 + 9.55 = 129.55 ≒ 130 (mm) can be set.

[0009] Also, since the bending range (total length of the bent portion) L on the central axis from the start to the end of bending the wire pipe is one-fourth of the circumference, L = 2πr / 4 = 204.1 ≒ 204 (mm). Therefore, following the general setting where the bending dimension position determined by securing the necessary distance from the pipe end is about 2 / 3 on the pipe end side within the bending range, since the aforementioned bending range (bending length) is 204 mm, the bending start position is about 136 mm from the bending dimension position toward the pipe end side.

[0010] Here, the distance from the bending dimension position to the bending start position is set to 130 mm. As a result, the distance from the bending dimension position to the bending end position is set to 204 - 130 = 74 mm.

[0011] Normally, the calculations for each position required for the bending process as described above are made in advance. Therefore, the operator first measures the required distance from the pre-calculated pipe end to the bending part on the surface of the target wire conduit, and marks it as a reference for the bending dimension position. As the mark, for example, a straight line perpendicular to the central axis is common.

[0012] Next, a linear mark serving as a reference for the starting position of bending is made at a position measured 130 mm from the bending dimension position toward the pipe end side, and a linear mark serving as a reference for the ending position of bending is made at a position measured 74 mm from the bending dimension position to the side opposite to the starting position of bending.

[0013] All these marks are made so as to line up in the same direction on the surface of the wire conduit. For marking, general felt pens or marking pens are used, and depending on the position, pens with different colors, thicknesses, etc. are used appropriately. Also, usually, the measurement of each position is performed using a tape measure such as a convex one.

[0014] Therefore, in the actual bending process, the operator first presses the working point of the hickey-type manual bender against the side opposite to the mark at the starting position of bending so that the above marks face upward, and bends the wire conduit by the action of a lever to give it a predetermined angle.

[0015] Then, while feeding the wire conduit forward little by little while maintaining the state where the above marks always face upward, this bending operation is repeated until the ending position of bending. In the bending process of the wire conduit 100 of E19 according to the above settings, for example, it is common to perform bending at angles of 18 degrees to 10 degrees with 5 to 9 bending times from the starting position of bending to the ending position of bending. Through such a series of bending steps, finally, the wire conduit is bent at an inner radius of 120 mm by 90 degrees.

[0016] In electrical wiring construction, bending of electrical conduit pipes may be performed on multiple conduit pipes, or there may be cases where bending is performed at multiple locations on a single long conduit pipe. Therefore, it is desired that the bending of each conduit pipe be carried out as efficiently as possible. On the other hand, in the bending of electrical conduit pipes using a manual bender, much depended on skilled workers.

[0017] Therefore, various ideas have been considered to enable more reliable and efficient bending to be carried out regardless of the skill level of the worker even in the bending of electrical conduit pipes using a manual bender. For example, Patent Document 1 discloses a bender auxiliary tool that measures the degree of bending while bending a pipe attached to the bender to achieve the desired degree of bending.

Prior Art Documents

Patent Documents

[0018]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0019] However, in the conventional bending of metal pipes, the procedures are complicated and time-consuming. This is the work of aligning with the bender and applying a plurality of marks used as a guide for the bending operation positions while measuring the lengths of each mark using a tape measure.

[0020] The marking of each position is generally performed not only at the bending dimension positions, the bending start position, and the bending end position as described above, but also at each position for each feed interval therebetween. Furthermore, marking is often carried out for each of two types of feed intervals, narrow and wide. For this reason, it is very complicated and inefficient to mark all the marks while measuring a very large number of position intervals and distances respectively.

[0021] Moreover, the measurement of each position interval and distance using a convex depends on the experience and skill level of the operator, and may be unstable to handle and unable to perform accurate measurement, resulting in a deviation between the calculated position and the mark. The above-mentioned vendor tool is provided with a measuring tool for measuring the moving distance due to the bending of the pipe, but it is used during the bending operation and does not assist in marking before the bending process. Currently, no tool has been developed to facilitate marking before the bending process.

[0022] In addition, according to the pipe design, in order to ensure the necessary distance from the pipe end, the bending process should be carried out at the bending dimension position measured from the pipe end by that distance.

[0023] However, some operators first perform the bending process at a position slightly longer than appropriate from the pipe end, and then cut the end of the metal pipe at the position where the necessary distance is measured from the bent portion. Thus, forming the pipe end at the correct distance position by cutting after the bending process is often done, and fixtures for this purpose have also been developed.

[0024] For example, Patent Document 2 discloses a cutting machine with a scale that enables accurate and rapid cutting of a long member bent at 90 degrees. It is described that such a cutting machine with a scale can also be used for cutting an electric wire pipe bent at 90 degrees.

[0025] However, in the procedure of cutting the end after bending the electric wire pipe, the cut-off part of the metal pipe becomes an end material with no use as a pipe, and a large amount of such waste end materials will be generated at each site. This ultimately leads to a waste of resources, which is not desirable from the perspective of the SDGs initiatives. Furthermore, the method of cutting the end cannot handle the case where a plurality of bent portions are provided on a single metal pipe.

[0026] Also, the scale of the above-mentioned cutting machine is for accurately determining the cutting position for the bent pipe, and cannot be used to mark each position necessary for the bending process without cutting the end later.

[0027] In view of the above problems, an object of the present invention is to easily and accurately perform the work of marking reference points for each position required for bending a metal pipe by a manual bender in a shorter time than before, regardless of the experience and skill level of the operator, thereby efficiently performing bending processing as designed without causing waste due to cutting off the ends of the metal pipe. To provide a metal pipe bending gauge jig and a metal pipe bending processing method using the jig.

Means for Solving the Problems

[0028] In order to achieve the above object, the metal pipe bending gauge jig according to the invention described in claim 1 is, for example, as shown in FIGS. 1 to 5, when attaching marks indicating a plurality of bending reference positions set for bending a target metal pipe with a predetermined inner bending radius and angle to the surface of the metal pipe, a metal pipe bending gauge jig that is attached to the metal pipe and has a scale line group for indicating each of the plurality of bending reference positions, A mounting portion that detachably fits onto the outer circumference of the metal pipe, A long measuring portion that is connected to the mounting portion and is positioned along the side surface of the metal pipe parallel to the central axis of the metal pipe in a state where the mounting portion is fitted onto the outer circumference of the metal pipe, On the surface of the measuring portion, the scale line group is provided along one longitudinal side thereof, The scale line group is As the plurality of bending reference positions, a bending dimension position separated from the pipe tip of the metal pipe by a predetermined required dimension, a bending start position separated from the bending dimension position by a predetermined distance toward the pipe tip side, and a bending end position separated from the bending dimension position by a predetermined distance on the side opposite to the pipe tip. Each scale line that appears as a straight line extending in a direction perpendicular to the longitudinal side for indicating the bending dimension indication position, the bending start indication position, and the bending end indication position respectively, and Between the bending start instruction position and the bending end instruction position, there are further feeding indication lines that appear as straight lines extending in a direction perpendicular to the longitudinal side at the feeding indication positions respectively indicating the preset feeding interval positions of the metal pipe. The mounting part is characterized in that it is arranged at one end or both ends in the longitudinal direction of the measuring part.

[0029] According to the metal pipe bending gauge jig described in claim 1 of the present invention, the mounting part can be fitted to the outer periphery of the target metal pipe. By this fitting, the long measuring part can be positioned at a predetermined position along the side surface of the metal pipe. Therefore, the scale lines of the bending dimension indication positions provided on the surface of the measuring part can be easily and quickly aligned with the marks attached to the bending dimension positions separated by a predetermined required dimension length from the pipe tip of the metal pipe in advance.

[0030] In addition, in the state where the alignment is completed, each scale line provided along the longitudinal side of the surface of the measuring part indicates the bending start position, the bending end position, and further the feeding interval positions therebetween along the side surface of the metal pipe. Therefore, by simply marking the surface of the metal pipe according to these scale lines, all the marks serving as references for all the positions required for the bending operation of the wire pipe can be completed.

[0031] Therefore, without performing the unstable and complicated operation of marking while measuring each distance using a tape measure such as a convex as in the prior art, and without requiring the operator to have experience and high skills, all the markings on the metal pipe can be completed more simply, quickly, and with higher accuracy than before.

[0032] In addition, the measuring part in the present invention is preferably made of a hard and lightweight material. For example, those made of plastic or cardboard are suitable. The scale line group can be provided by directly printing each scale line on the surface of the member or by adhering a printed matter.

[0033] Further, the mounting portion that is detachably fitted to the outer periphery of the metal pipe is preferably provided at one end in the longitudinal direction of the measuring portion. However, if it is provided at both ends, a more stable mounting state can be obtained during marking. As specific examples of the mounting portion, a latching member having an inner diameter slidable with respect to the outer periphery of the target metal pipe and having a reverse U-shaped cross section, or a clamp that sandwiches the pipe with upper and lower members, is simple and preferable.

[0034] When the mounting portion is a latching member having a reverse U-shaped cross section, it can be mounted simply by hooking it on the target position of the metal pipe. Therefore, even when the bending target area is at a distance from the pipe end, the mounting operation is simple. In addition, since it is easy to slide along the metal pipe with the measuring portion, the positioning adjustment is also easy.

[0035] In addition, in the case of a clamp, since the pipe is sandwiched by the upper and lower members, it can be mounted almost directly on the target position with respect to the metal pipe, and a more stable mounting than the latching member can be obtained. As a specific clamp mechanism, any mechanism that can temporarily fix the pipe during marking may be used, and it may be a screw type or a spring type. The screw type can be mounted more firmly, but the spring type is preferable in terms of easy attachment and detachment.

[0036] Further, the upper and lower members of the clamp have a substantially semicircular cross-sectional shape such that the upper and lower contact regions with the outer peripheral surface of the pipe are substantially circular in cross section and surround the pipe. Furthermore, since the outer diameter dimensions of the objects that can be clamped between the upper and lower members can have a width, if the measuring portion can be commonly used, it can be applied to a plurality of types of metal pipes having different outer diameters.

[0037] The metal pipe bending gauge jig according to the invention described in claim 2, for example, as shown in FIGS. 1 to 5, among the scale line groups, the scale line at the bending dimension indication position has a length different from that of other scale lines, and / or character notation indicating that the scale line indicates the bending dimension position is provided on the surface of the measuring portion.

[0038] According to the metal pipe bending gauge jig described in claim 2 of the present invention, since the scale line of the bending dimension indication position for aligning the initial measuring part of the metal pipe bending gauge jig with the target metal pipe can be easily distinguished from other scale lines, the positioning during the attachment of the metal pipe bending gauge jig can be completed in a short time.

[0039] The metal pipe bending gauge jig according to the invention described in claim 3, for example, as shown in FIGS. 12 and 13, the measuring part is provided with a first scale line group corresponding to the first metal pipe on one longitudinal side, and a second scale line group set for a second metal pipe having different outer diameters and inner diameters from the first metal pipe is provided on the other longitudinal side. One end of the measuring part is rotatably connected to the mounting part, and it is characterized in that it can be rotated by at least 180 degrees around the one end between a first mounting position where the first scale line group is positioned along the side surface of the first metal pipe and a second mounting position where the second scale line group is positioned along the side surface of the second metal pipe.

[0040] According to the metal pipe bending gauge jig described in claim 3 of the present invention, a first scale line group provided on one longitudinal side is used as the first scale line group, and a second scale line group indicating all positions required for bending a second metal pipe having a different diameter from the first metal pipe corresponding to this first scale line group is provided on the other longitudinal side of the measuring part.

[0041] By providing two types of scale line groups using both longitudinal sides of the measuring part in this way, it is possible to substantially use two types of gauge jigs for the first and second metal pipes in combination with one gauge jig.

[0042] Further, one end of the measuring section is rotatable relative to the mounting section, and the measuring section is displaceable by 180 degrees between a first mounting position where the first scale line group is positioned along the side surface of the first metal pipe and a second mounting position where the second scale line group is positioned along the side surface of the second metal pipe. Therefore, by simply rotating the measuring section, it is possible to immediately switch to the scale line group corresponding to the target metal pipe and position it on the side surface of the metal pipe. In this case, if the mounting section is a clamp, it can correspond to both the first metal pipe and the second metal pipe having different outer diameters from each other.

[0043] The metal pipe bending gauge jig according to the invention described in claim 4, for example, as shown in FIGS. 10 and 11, the measuring section is composed of a plurality of divided parts, and both ends of adjacent divided parts overlap each other vertically and are rotatably connected, and is characterized in that it is foldable.

[0044] According to the metal pipe bending gauge jig described in claim 4 according to the present invention, since the measuring section is composed of a plurality of divided parts and is foldable, if it is extended only during use and folded when not in use, the occupied space can be reduced and transportation and storage can be made convenient.

[0045] In addition, during use, it is desirable to provide a locking mechanism that can fix the extended state so that the measuring section is extended and the longitudinal pieces on both sides are maintained in a continuous straight line state. As this locking mechanism, a simple configuration is preferable. For example, a locking mechanism adopted in a folding type measuring ruler commercially available as a so-called folding ruler is suitable.

[0046] Specifically, adjacent divided parts are connected by pinning their ends to each other, but are rotatable relative to each other around the pin, and are formed on the upper surface of the lower end and the lower surface of the upper end. It is a locking mechanism in which relatively shallow concave and convex portions fit when the longitudinal pieces of the divided parts are continuous in a straight line.

[0047] Also, by the biasing force that rotates one divided portion with respect to the other, the fitting between the concave portion and the convex portion can be disengaged, and the object can shift to the folded state. If the scale portion is a thin plate, such fitting and release between the concave portion and the convex portion are achieved by slight elastic deformation of the constituent members, so it is not necessary to apply a large force.

[0048] The method for bending a metal pipe according to the invention described in claim 5 is, for example, as shown in FIGS. 2 to 8, a method for bending a metal pipe using the metal pipe bending gauge jig described in claim 1, an initial setting step of marking the surface of the target metal pipe at a bending dimension position separated by a predetermined required dimension from the pipe end of the metal pipe; a mounting and alignment step of fitting the mounting portion to the metal pipe and aligning the scale portion along the side surface of the metal pipe, and aligning the scale line at the bending dimension indication position among the scale line groups of the scale portion with the mark at the bending dimension position on the surface of the metal pipe; a first marking step of, after the mounting and alignment step, marking the start bending position mark and the end bending position mark on the extensions of the scale lines at the start bending indication position and the end bending indication position among the scale line groups on the surface of the metal pipe; a second marking step of, after the first marking step, marking the feed interval position marks on the extensions of the scale lines at the feed indication position among the scale line groups on the surface of the metal pipe; a step of releasing the fitting by the mounting portion and removing the metal pipe bending gauge jig from the metal pipe after the second marking step; and a bending step of, with respect to the metal pipe, while feeding the metal pipe from the marking site of the start bending position to the marking site of the end bending position at intervals of the marks at the feed interval positions, sequentially pressing the action point of the manual bender at each site to repeat the bending process.

[0049] According to the method for bending a metal pipe according to claim 5 of the present invention, in the initial setting step, if a mark is made on the surface of the target metal pipe at a position of a predetermined required dimension length from a predetermined pipe end, then in the next mounting alignment step, when mounting the metal pipe bending gauge jig, the alignment is completed simply by aligning the graduation line at the bending dimension position among the graduation line groups of the measuring portion.

[0050] Therefore, after the alignment is completed, by simply making a mark on the surface of the metal pipe as an extension of each graduation line of the measuring portion along the side surface of the metal pipe, the marking for indicating the bending start position and the bending end position as the first marking step, and the marking for indicating each feed interval position as the second marking step can be easily completed in a short time without using a tape measure such as a convex one.

[0051] As a result, after completing the marking for all necessary positions in a short time, if the bending process is appropriately repeated for each mark, a desired bending radius can be obtained, so the working efficiency of the entire bending process is greatly improved compared to the conventional method.

[0052] Also, in actual bending, from the bending start position to the bending end position, while gradually shifting the metal pipe relative to the action point of the bender and feeding it at equal intervals or every half interval, the bending operation is repeatedly performed at each position little by little. Therefore, the inner diameter of the metal pipe is not crushed, and the desired inner bending radius can be successfully reached.

[0053] The method for bending a metal pipe according to the invention described in claim 6, for example, as shown in FIG. 9, includes a confirmation step of applying an arc-shaped bending die having an outer peripheral radius that matches the predetermined inner bending radius to the bent portion of the metal pipe after the bending step, and checking for the presence or absence of a gap between the inner side of the bent portion and the outer periphery of the bending die. It is further characterized by further including a fine adjustment step of repeating the bending process of the metal pipe until the gap disappears when there is a gap in the confirmation step.

[0054] According to the method for bending a metal pipe according to claim 6 of the present invention, after repeating the bending process while feeding at predetermined intervals from the starting position of bending to the ending position of bending, the bending degree can be confirmed by applying a bending die to the inside of the bent portion of the metal pipe.

[0055] If there is a gap between the contact portion of the bending die, until this gap disappears, by repeating the bending process of pushing and bending while feeding the wire conduit for each mark and performing fine adjustment, the target bending process can be achieved with higher precision. In the actual bending process in this fine adjustment step, each pushing and bending angle is kept small and the gap is gradually eliminated.

Effect of the Invention

[0056] As described above, the metal pipe bending gauge jig according to the present invention is simply mounted via a mounting portion that is detachably fitted to the outer periphery of the target metal pipe, and a long measuring portion provided with a scale line group for indicating each position necessary for bending the wire conduit on the surface is positioned along the side surface of the metal pipe. Therefore, if the scale line at the bending dimension indication position within the scale line group is aligned with the mark at the bending dimension position separated by a predetermined required dimension from a predetermined pipe tip, the other positions of the metal pipe will be naturally indicated, and marks can be easily made along each scale line respectively.

[0057] For this reason, without performing the complicated operation of making marks while measuring each distance using an unstable tape measure such as a convex tape measure as in the prior art, and without requiring experience and high skills from the operator, all the marking necessary for the bending operation of the wire conduit can be completed simply and with high precision in a shorter time than before. Moreover, since it is not necessary to cut the pipe end at the position where the predetermined length is measured after the bending process, the generation of waste end materials is suppressed, contributing to the realization of the efficiency improvement of the entire bending process and the avoidance of resource waste.

Brief Description of the Drawings

[0058]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

MODE FOR CARRYING OUT THE INVENTION

[0059] Hereinafter, with reference to the drawings, an embodiment of the present invention will be described.

[0060] <Embodiment> FIGS. 1 to 13 show an embodiment of a metal pipe bending gauge jig according to the present invention. As shown in FIG. 1, the metal pipe bending gauge jig 10 in this embodiment mainly includes a long measuring portion 12 and latching members (11A, 11B) having an inverted U-shaped cross section that are respectively fixed to both ends in the longitudinal direction of the measuring portion 12 as a mounting portion that detachably fits onto the outer periphery of the electric wire pipe 100.

[0061] On the surface of the measuring portion 12, along one longitudinal side 13, scale lines for respectively indicating a plurality of bending reference positions required for bending the electric wire pipe 100 are provided as straight lines extending in a direction orthogonal to the longitudinal side 13, constituting a set of scale line groups 20.

[0062] Then, by simply hooking both latching members (11A, 11B) onto the electric wire pipe 100, the metal pipe bending gauge jig 10 is attached to the electric wire pipe 100, and at the same time as the attachment, the measuring portion 12 is positioned along the side surface of the electric wire pipe 100 in parallel with the central axis of the electric wire pipe 100.

[0063] Incidentally, such a mounting portion by the latching members (11A, 11B) is sufficient for attaching the metal pipe bending gauge jig 10 to the electric wire pipe 100 even if only one is provided at either one end of the measuring portion 12. In this embodiment, two latching members (11A, 11B) provided at both ends of the measuring portion 12 are used to obtain a more stable mounting state.

[0064] The scale line group 20 provided on the surface of the measuring part 12 includes a scale line 21 of a bending dimension indication position for indicating a bending dimension position separated by a required dimension from the tip of a predetermined metal pipe among a plurality of indication positions, a scale line 22 of a bending dimension indication position for indicating a bending start position separated by a predetermined distance from the bending dimension position toward the pipe tip side, and a scale line 23 of a bending end indication position for indicating a bending end position separated by a predetermined distance from the bending dimension position to the side opposite to the pipe tip.

[0065] In the metal pipe bending gauge jig 10 according to the present embodiment, it is a commercially available non-threaded electric wire pipe (E pipe) called E19, and shows a case where an electric wire pipe 100 with an outer diameter of 19.1 mm and an inner diameter of 16.7 mm is targeted and a 90-degree bending process with an inner bending radius of 120 mm is performed.

[0066] In this case, each setting is as follows: the bending radius r to the pipe center is 130 mm, the bending length of the electric wire pipe 100 is 2πr / 4 ≈ 204 mm = L, the distance from the bending dimension position to the bending start position is 130 mm, and the distance from the bending dimension position to the bending end position is 74 mm.

[0067] Therefore, in the scale line group 20 of the measuring part 12 in the present embodiment, a scale line 22 of a bending start indication position is provided at a distance of 130 mm in the pipe tip direction from the scale line 21 of the bending dimension indication position, and a scale line 23 of a bending end indication position is provided at a distance of 74 mm in the opposite direction from the scale line 21 of the bending dimension indication position.

[0068] Also, in the present embodiment, the feeding interval α of the electric wire pipe 100 in the bending process is set to 1 / 10 of the total length L of the bent part from the bending start position to the bending end position, that is, 20.4 mm. Nine feeding scale lines 24 are provided at intervals of 20.4 mm between the scale line 22 and the scale line 23 as straight lines thinner and shorter than these scale lines (22, 23) and the scale line 21 of the bending dimension indication position.

[0069] In addition, in order for the operator to be able to select a finer feed interval according to the ease of operation and personal preference, between each of the feed graduation lines 24, a fine feed graduation line 25 with an interval β that is half of the interval α, i.e., an interval of 10.2 mm, appears, and this is provided as a shorter dashed line.

[0070] If each of the graduation lines (21, 22, 23, 24, 25) has different lengths, thicknesses, and colors from each other, the positions indicated by each can be distinguished at a glance. In addition to or instead of this, for particularly important graduation lines, what position each indicates may be indicated on the surface of the scale portion 12 with characters, symbols, etc.

[0071] In this embodiment, notation characters 26 for "bending dimension" are provided near the graduation line 21 at the bending dimension indication position, notation characters 27 for "start of bending" are provided near the graduation line 22 at the start of bending indication position, and notation characters 28 for "end of bending" are provided near the graduation line 23 at the end of bending indication position, respectively.

[0072] In addition to this, character notation 30 indicating that the metal pipe bending gauge jig 10 according to this embodiment is a gauge jig for bending an E19 electric wire pipe with an inner radius of 120 mm is further provided on the surface of the scale portion 12. Also, the respective distances from the bending dimension position to the start of bending position and to the end of bending position may be further indicated.

[0073] Each of the above graduation lines (21, 22, 23, 24, 25), notation characters (26, 27, 28, 30), distances, etc. can be provided by directly printing on the surface of the scale portion 12 or by adhering a printed matter.

[0074] The metal pipe bending gauge jig 10 according to this embodiment is not limited to being for the E19 electric wire pipe 100 exemplified above, and can be variously set as having a scale portion provided with graduation lines corresponding to the bending radius determined based on the outer diameter and inner diameter of the target electric wire pipe, and the respective distance positions from the bending dimension position to the start of bending position and to the end of bending position.

[0075] Therefore, it is also possible to prepare in advance a metal pipe bending gauge jig having different measuring parts according to the type and design of the conduit. In this case, if character notations indicating information including the name of the target conduit as described above are provided on the surface of each measuring part, it is suitable for selecting and using an appropriate metal pipe bending gauge jig.

[0076] The marking on the conduit 100 using the metal pipe bending gauge jig 10 according to the present embodiment having the above configuration is performed in the following procedure.

[0077] First, as shown in FIG. 2, the mark 101 at the bending dimension position provided in advance on the target conduit 100 is confirmed, and the metal pipe bending gauge jig 10 is moved so that the scale line 21 at the bending dimension indication position of the corresponding measuring part 12 is aligned with the mark 101 at the bending dimension position.

[0078] Then, as a mounting / aligning step, as shown in FIG. 3, both latching members (11A, 11B) are hooked on the outer periphery of the conduit 100, and the position of the metal pipe bending gauge jig 10 is adjusted so that the scale line 21 coincides with the mark 101.

[0079] As a result, the mounting of the metal pipe bending gauge jig 10 on the conduit 100 is completed, and one longitudinal side 13 of the measuring part 12 provided with the scale line group 20 is placed along the side surface of the conduit 100.

[0080] In the state where the mounting / aligning of the metal pipe bending gauge jig 10 on the conduit 100 is completed, as a first marking step, as an extension line of the scale line 22 at the bending start indication position, a mark 102 indicating the bending start position is made on the surface of the conduit 100 with a thick and long line using a felt pen or a marking pen, and as an extension line of the scale line 23 at the bending end indication position, a mark 103 indicating the bending end position is similarly made on the surface of the conduit 100 with a thick and long line using a felt pen or a marking pen.

[0081] Next, as a second marking step, between the marks 102 and 103 indicating the starting and ending positions of the bending of the wire conduit 100, nine fine feed interval marks 104 are made as relatively thin and short lines, as extensions of the nine feed graduation lines 24 of the measuring portion 12.

[0082] Next, as shown in FIG. 5, between the feed interval marks 104, ten fine feed interval marks 105 are made as relatively thin and short lines, as extensions of the ten fine feed graduation lines 25. This completes all the markings necessary for bending the wire conduit 100.

[0083] These feed interval marks 104 and fine feed interval marks 105 are preferably made using a felt pen or marking pen with a color different from that of the marks 101 indicating the bending dimension positions and the marks (102, 103) indicating the starting and ending positions of bending, as this makes it easier to distinguish them.

[0084] After all the above marking steps are completed, the removal of the metal pipe bending gauge jig 10 is completed simply by removing both latching members (11A, 11B) from the wire conduit 100.

[0085] The bending process of the wire conduit 100 with all the necessary marks (102, 103, 104, 105) made using the manual bender 200 is as follows.

[0086] First, as shown in FIG. 6, the portion of the wire conduit 100 on the tip side (right side in the drawing) from the starting position of bending is inserted between the bending portion 211 and the locking portion 213 of the head portion 210 of the manual bender 200 to be in a latched state.

[0087] At this time, the orientation of the wire conduit 100 is adjusted so that all the marks (102, 103, 104, 105) are upward. Also, hereafter, during the bending process, the orientation of the wire conduit 100 is maintained so that these marks (102, 103, 104, 105) are always upward and visible to the operator 300.

[0088] With the wire conduit 100 in the above-mentioned hooked state, position it so that the mark 102 indicating the starting position of bending comes onto the top 212 of the curved portion 211 which is the point of action of the manual bender 200. After this positioning, the bending process is started.

[0089] First, the operator 300 fixes the head portion 210 by holding the bender support column 220 with one hand and pressing it against the ground so as to maintain this positioned state. Then, with the other hand, hold the front side (left side in the drawing) of the wire conduit 100 and push it down by about 10 degrees while aligning it along the groove in the curved portion 211. As a result, due to the lever action, the wire conduit 100 is pushed and bent by a predetermined angle at the starting position of bending.

[0090] After performing the first bending process at the mark 102 indicating the starting position of bending in the above procedure, send out the wire conduit 100 forward (right side in the drawing) and position the first feed interval mark 104 on the top 212 of the curved portion 211. Here, similar to the previous procedure, push and bend the near side of the wire conduit 100 downward by about 10 degrees due to the lever action.

[0091] As shown in FIG. 7, repeat such feeding and pushing - bending operations for each feed interval mark 104. Then, as shown in FIG. 8, perform the pushing - bending at the mark 103 indicating the end position of bending as the last bending operation.

[0092] In addition, in the above bending process, the case where the bending operation is repeated for each feed interval mark 104 with a relatively wide feed interval is shown. However, when the operator 300 finds it easier to perform the bending operation with a finer feed interval, it is also possible to selectively perform the bending operation for each fine feed interval mark 105 with a relatively narrow interval.

[0093] After the completion of the above bending process, as shown in FIG. 9(a), remove the wire conduit 100 from the head portion 210 of the manual bender 200 and place it on a plane. Then, as shown in FIG. 9(b), confirm the degree of bending by bringing the bending die 40 having an outer peripheral radius that matches the inner bending radius of the target prepared in advance into contact with the inside of the bent portion of the wire conduit 100.

[0094] That is, in the present embodiment, a bending die 40 with an outer peripheral bending radius of 120 mm and a 90-degree bend was brought into contact with the inside of the bent portion of the electric wire conduit 100, and the presence or absence of a gap between the two was confirmed.

[0095] When the bent portion of the electric wire conduit 100 has not reached the target bending degree, a gap d can be seen between the electric wire conduit 100 and the outer periphery of the bending die 40. In this confirmation step, if the gap d is confirmed, as a fine adjustment step, the bending process of the electric wire conduit 100 as described above is repeated until the gap d disappears, and finally the target bending degree is achieved. Thereby, the bending operation of the electric wire conduit 100 is completed.

[0096] In the above embodiment, the metal pipe bending gauge jig 10 of the type in which the scale line group 20 is provided only on one longitudinal side 13 of the measuring portion 12 to correspond to one type of electric wire conduit 100 has been exemplified. However, as the present invention, it is also possible to configure a metal pipe bending gauge jig that can be used for two types of electric wire conduits by providing different scale line groups on the longitudinal sides on both sides of the measuring portion.

[0097] FIGS. 10 to 13 show a metal pipe bending gauge jig 50 corresponding to two types of electric wire conduits as another embodiment of the metal pipe bending gauge jig according to the present invention. Further, the metal pipe bending gauge jig 50 in the present embodiment includes a foldable measuring portion 52.

[0098] That is, in the present embodiment, four divided portions (52A, 52B, 52C, 52D) are connected to form one long measuring portion 42. The four divided portions (52A, 52B, 52C, 52D) are rotatably connected such that both ends of adjacent divided portions overlap each other vertically. As shown in FIG. 10, a folded state is obtained by rotating them relative to each other until all the divided portions (52A, 52B, 52C, 52D) are completely overlapped.

[0099] One end of the split portion 52A at one end of the ruler portion 52 is rotatably connected to the clamp 51 as a rotation center 55. In the folded state of the ruler portion 52 in FIG. 10, as shown in FIG. 11, by pulling out the split portion 52D at the other end distally from the clamp 51, the four split portions (52A, 52B, 52C, 52D) relatively rotate in a direction to open from each other and can be extended linearly as shown in FIG. 12 or FIG. 13.

[0100] The clamp 51 is such that the upper and lower clamp members (51A, 51B) are spring-biased in a direction to close toward each other and the rear ends are connected to each other. At each tip of the upper and lower clamp members (51A, 51B), upper and lower concave portions (RA, RB) having a semi-circular cross-section that faces each other and is substantially cylindrical are formed.

[0101] Therefore, the wire conduit is clamped by spring bias inside the upper and lower concave portions (RA, RB) that face each other in a closed state, and the state of the metal pipe bending gauge jig 50 being attached to the wire conduit is obtained. Also, if the upper and lower clamp members (51A, 51B) are pushed apart from each other against this spring bias, the metal pipe bending gauge jig 50 can be easily removed from the wire conduit.

[0102] In this embodiment, the inner diameters of the upper concave portion RA and the lower concave portion RB are different from each other, whereby the clamp 51 can be attached to two types of wire conduits having different outer diameters. Here, an example is illustrated in the case where the metal pipe bending gauge jig 50 is for a wire conduit 110 called E25 having an outer diameter of 25.4 mm and an inner diameter of 23 mm and a wire conduit 120 called E31 having an outer diameter of 31.8 mm and an inner diameter of 29 mm among commercially available non-threaded wire conduits (E pipes).

[0103] In the metal pipe bending gauge jig 50 of this embodiment, as a single ruler portion 52 in which all the split portions (52A, 52B, 52C, 52D) are extended linearly, a first scale line group 60 for the wire conduit (E25) 110 is provided along one longitudinal side 53, and a second scale line group 70 for the wire conduit (E31) 120 is provided along the other longitudinal side 54.

[0104] The first and second scale line groups (60, 70) are determined based on the bending radius according to the predetermined design of each electric wire conduit (110, 120) to be bent, and the bending length, the distance from the bending dimension position set as a ratio within it to the bending start position, and the distance to the bending end position are calculated in advance, and scale lines for indicating respective corresponding positions are arranged.

[0105] For example, in the first scale line group 60, the total length of the bent portion as the bending range is 270 mm, the scale line 62 indicating the bending start position is provided at a position separated from the scale line 61 at the bending dimension indication position by a distance of 172 mm, and the scale line 63 indicating the bending end position is provided at a position separated from the scale line 61 by a distance of 98 mm.

[0106] Also, as the feeding interval, it is set to 1 / 10 of the total length of the bent portion, that is, 27 mm. Between the scale lines 62 and 63, nine feeding scale lines 64 are provided at intervals of 27 mm as straight lines thinner and shorter than these scale lines (62, 63) and the scale line 61 at the bending dimension indication position. Further, in order to be able to select a finer feeding interval, fine feeding scale lines 65 with an interval of 1 / 2 of that interval, that is, an interval of 13.5 mm, are provided as shorter dashed lines between the respective feeding scale lines 64.

[0107] On the other hand, in the second scale line group 70, the total length of the bent portion is 330 mm, the scale line 72 indicating the bending start position is provided at a position separated from the scale line 71 at the bending dimension indication position by a distance of 210 mm, and the scale line 73 indicating the bending end position is provided at a position separated from the scale line 71 by a distance of 120 mm.

[0108] Also, as the feeding interval, it is set to 1 / 10 of the total length of the bent portion, that is, 33 mm. Between scale line 72 and scale line 73, nine feeding scale lines 74 are provided at intervals of 33 mm as straight lines thinner and shorter than these scale lines (72, 73) and the scale line 71 at the bending dimension indication position. In addition, in order to be able to select a finer feeding interval, between each pair of feeding scale lines 74, fine feeding scale lines 75 that appear at an interval of 1 / 2 of that interval, that is, an interval of 16.5 mm, are provided as even shorter dashed lines.

[0109] In the step of marking the wire conduits (110, 120) with the metal pipe bending gauge jig 50 of the present embodiment having the above configuration, after the attachment to the target wire conduit, the procedure is the same as when using the metal pipe bending gauge jig 10 of the aforementioned embodiment.

[0110] First, when targeting the wire conduit (E25) 110, the measuring portion 52 with all the divided portions (52A, 52B, 52C, 52D) stretched out linearly is rotated to the first mounting position where one longitudinal side 53 provided with the first scale line group 60 faces the mounting direction of the wire conduit 110 by the clamp 51.

[0111] Therefore, as shown in FIG. 12, the metal pipe bending gauge jig 50 is mounted by clamping the wire conduit 110 with the clamp 51. In this mounted state, one longitudinal side 53 of the measuring portion 52 is arranged parallel to the side surface of the wire conduit 110, but alignment is performed so that the scale line 61 at the bending dimension indication position within the first scale line group 60 is located on the same extension line as the mark 111 at the bending dimension position previously attached to the surface of the wire conduit 110.

[0112] After this alignment, by simply sequentially making linear marks on the surface of the wire conduit 110 corresponding to the extension lines of each scale line (62, 63, 64, 65), the necessary marking process can be completed easily and in a short time.

[0113] The bending process of the wire conduit 110 by the manual bender 200 is efficiently performed using each mark as a guide when repeatedly pushing and bending while sequentially feeding out the wire conduit 110 at predetermined intervals from the bending start position to the bending end position.

[0114] Also, when the wire conduit (E31) 120 is the target, the measuring part 52 with all the divided parts (52A, 52B, 52C, 52D) stretched straight is rotated 180 degrees in the opposite direction compared to when the wire conduit (E25) 110 is the target, and is rotated to the first mounting position where the other long side 54 facing the wire conduit 120 in the mounting direction by the clamp 51 is provided with the second scale line group 70.

[0115] Therefore, as shown in FIG. 13, in the state where the metal pipe bending gauge jig 50 is mounted by clamping the wire conduit 120 with the clamp 51, the other long side 54 of the measuring part 52 is arranged in parallel along the side surface of the wire conduit 120. Thus, alignment is performed so that the scale line 71 at the bending dimension indication position among the second scale line group 70 is located on the same extension line as the mark 121 at the bending dimension position previously attached to the surface of the wire conduit 120.

[0116] After this alignment, by simply sequentially making linear marks on the surface of the wire conduit 120 corresponding to the extension lines of each scale line (72, 73, 74, 75), the necessary marking process can be completed easily and in a short time.

[0117] The bending process of this wire conduit 120 by the manual bender 200 is also efficiently performed using each mark as a guide when repeatedly pushing and bending while sequentially feeding out the wire conduit 120 at predetermined intervals from the bending start position to the bending end position.

[0118] As described above, in the metal pipe bending gauge jig 50 according to this embodiment, which is provided with two types of scale line groups (60, 70) on both longitudinal sides (53, 54) of the measuring part 52, it is possible to mark two types of wire pipes (110, 120) with different outer diameters with just one jig. Therefore, it is more convenient to handle than preparing and replacing corresponding metal pipe bending gauge jigs one by one for each type, and it is also more convenient for transportation and storage.

[0119] In addition, by making the measuring part 52 foldable, it further contributes to the simplification of transportation and storage.

Industrial Applicability

[0120] The metal pipe bending gauge jig of the present invention is applicable not only to the bending operation of wire pipes but also to any object that requires marking positions such as the inner radius of the bent part, the starting position of bending, the ending position of bending, and the feeding interval between them based on prior calculations, and is applicable to various metal pipes.

[0121] In addition, the bending process of the target metal pipe is not limited to being performed by a manual bender. As long as the pre - attached marks can be used, it is applicable to the marking of metal pipes that are bent by a machine.

Explanation of Reference Numerals

[0122] 10: Metal pipe bending gauge jig 11A, 11B: Hanging members 12: Measuring part 13: One longitudinal side (of the measuring part) 20: Scale line group 21: Scale line (bending dimension indication position) 22: Scale line (bending start indication position) 23: Scale line (bending end indication position) 24: Feeding scale line 25: Fine feeding scale line 26, 27, 28, 30: Notation characters 40: Bending die d: Gap 50: Metal pipe bending gauge jig 51: Clamp 51A: Upper clamp member 51B: Lower clamp member RA: Upper concave part RB: Lower concave part 52: Measuring part 52A, 52B, 52C, 52D: Divided parts 53: One longitudinal side 54: The other longitudinal side 55: Rotation center 60: First scale line group 61: Scale line (bending dimension indication position) 62: Scale line (bending start indication position) 63: Scale line (bending end indication position) 64: Feed scale line 65: Fine feed scale line 70: Second scale line group 71: Scale line (bending dimension indication position) 72: Scale line (bending start indication position) 73: Scale line (bending end indication position) 74: Feed scale line 75: Fine feed scale line 100: Electric wire pipe (E19) 101: Mark (bending dimension position) 102: Mark (bending start position) 103: Mark (bending end position) 104: Feed interval mark 105: Fine feed interval mark 110: Electric wire pipe (E25) 111: Mark (bending dimension position) 120: Electric wire pipe (E31) 121: Mark (bending dimension position) 200: Manual bender 210: Head part 211: Curved part 212: Top part 213: Locking part 220: Bender support 300: Operator

Claims

1. When attaching marks indicating a plurality of bending reference positions set for bending a target metal pipe with a predetermined inner bending radius and angle to the surface of the metal pipe, a metal pipe bending gauge jig that is attached to the metal pipe and has a scale line group for indicating each of the plurality of bending reference positions, A mounting portion that detachably fits onto the outer circumference of the metal pipe, A long measuring portion that is connected to the mounting portion and is positioned along the side surface of the metal pipe parallel to the central axis of the metal pipe in a state where the mounting portion is fitted onto the outer circumference of the metal pipe, On the surface of the measuring portion, the scale line group is provided along one longitudinal side thereof, The scale line group, As the plurality of bending reference positions, a bending dimension position that is separated from the pipe tip of the metal pipe by a predetermined required dimension, a bending start position that is separated from the bending dimension position by a predetermined distance toward the pipe tip side, and a bending end position that is separated from the bending dimension position by a predetermined distance on the side opposite to the pipe tip. Each has a scale line that appears as a straight line extending in a direction perpendicular to the longitudinal side for a bending dimension indication position, a bending start indication position, and a bending end indication position, respectively, and Between the bending start indication position and the bending end indication position, there are further feed scale lines that appear as straight lines extending in a direction perpendicular to the longitudinal side for each feed indication position indicating a predetermined feed interval position of the metal pipe, The mounting portion is arranged at one end or both ends in the longitudinal direction of the measuring portion. The metal pipe bending gauge jig is characterized by this.

2. Among the scale line group, the scale line of the bending dimension indication position has a different length from other scale lines, and / or a notation character indicating that the scale line indicates the bending dimension position is provided on the surface of the measuring portion. The metal pipe bending gauge jig according to claim 1 is characterized by this.

3. The object portion is provided with a first scale line group corresponding to the first metal pipe on one of the longitudinal sides, and a second scale line group set for a second metal pipe having an outer diameter and an inner diameter different from those of the first metal pipe is provided on the other longitudinal side. One end of the object portion is rotatably connected to the mounting portion, and at least 180 degrees around the one end between a first mounting position where the first scale line group is positioned along the side surface of the first metal pipe and a second mounting position where the second scale line group is positioned along the side surface of the second metal pipe. The metal pipe bending gauge jig according to claim 1 or 2, characterized in that it is rotatable.

4. The object portion is composed of a plurality of divided parts, and both ends of adjacent divided parts are rotatably connected so as to overlap each other vertically, and is foldable. The metal pipe bending gauge jig according to claim 1 or 2, characterized in that it is foldable.

5. A method for bending a metal pipe by a manual bender using the metal pipe bending gauge jig according to claim 1, An initial setting step of marking the surface of the target metal pipe at a bending dimension position separated by a predetermined required dimension from the pipe end of the metal pipe, A mounting / aligning step of fitting the mounting portion to the metal pipe and aligning the object portion along the side surface of the metal pipe, and aligning the scale line at the bending dimension indication position among the scale line groups of the object portion with the mark at the bending dimension position on the surface of the metal pipe, After the mounting / aligning step, a first marking step of marking a bending start position mark and a bending end position mark on the surface of the metal pipe on the extensions of the scale lines at the bending start indication position and the bending end indication position among the scale line groups, After the first marking step, a second marking step of marking a feed interval position mark on the extensions of the scale lines at the feed indication position among the scale line groups on the surface of the metal pipe, After the second marking step, a step of releasing the fitting by the mounting portion and removing the metal pipe bending gauge jig from the metal pipe. For the metal pipe, while feeding it out at intervals of the marks at the feeding interval positions from the marking position of the bending start position to the marking position of the bending end position, the bending process is repeated by sequentially pressing the action point of the manual bender at each part. A method for bending a metal pipe, characterized by comprising:

6. A confirmation step of applying an arc-shaped bending die having an outer peripheral radius that matches the predetermined inner bending radius to the bent portion of the metal pipe after the bending step, and checking for the presence or absence of a gap between the inner side of the bent portion and the outer periphery of the bending die; The method for bending a metal pipe according to claim 5, further comprising a fine adjustment step of repeating the bending process of the metal pipe until the gap disappears when there is a gap in the confirmation step.

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