Marking jig

Abstract

To provide a marking jig that can properly perform marking work on pipes. [Solution] The marking jig 1 is used to draw a mark 31 on a pipe P1 at a predetermined distance from the tip of the pipe P1. The marking jig 1 comprises a first cylindrical portion 11 into which the pipe P1 is inserted, a contact portion 16 provided inside the first cylindrical portion 11 that contacts and defines the insertion position of the tip of the pipe P1, and a marking hole 19 provided at a predetermined distance from the contact portion 16 toward the open end face 21 of the first cylindrical portion 11 and passing through the first cylindrical portion 11. The open end face 21 of the first cylindrical portion 11 has a concave portion 22 and a convex portion 23 provided at different positions in the circumferential direction. Therefore, it is easy to notice misuse of the marking jig from the non-planar appearance of the open end face 21, or from the feeling of discomfort caused by the uneven shape when moving the marker along the open end face 21.

Description

Technical Field

[0001] The present invention relates to a marking jig used in operations such as connecting pipes constituting, for example, water supply pipes, hot water pipes, floor heating, road heating, etc. to pipe fittings. Specifically, in the connection operation, for the purpose of preventing poor connection of pipes, by accurately measuring and marking a position at a predetermined length away from the tip of the pipe, it relates to a marking jig configured to easily grasp the length of the pipe to be inserted into the pipe fitting.

Background Art

[0002] Patent Document 1 discloses a marking jig provided with a cylindrical portion into which a pipe is inserted. An abutting portion against which the tip of the pipe abuts is formed in the inner back portion of the cylindrical portion. A marking hole is formed through at a position in the cylindrical portion at a predetermined length away from the abutting portion toward the opening end face side.

[0003] And, with the tip of the pipe abutted against the abutting portion, by marking the outer peripheral surface of the pipe using the marking hole as a guide for a marker, an operator who sees the drawn mark can easily grasp the length of the pipe to be inserted into the pipe fitting.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the marking jig of Patent Document 1, the marking hole is formed at a position away from the opening end face of the cylindrical portion. Also, the opening end face of the cylindrical portion is composed of a single plane as a whole.

[0006] Here, the marking jig in Patent Document 2 differs from the marking jig in Patent Document 1 in that it does not have a marking hole, and the marking is done by using the open end face of the cylindrical part (which as a whole consists of a single plane) as a guide for the marker.

[0007] Therefore, for example, an operator who is accustomed to using the marking jig described in Patent Document 2 may mistakenly use the open end face of the cylindrical part as a guide for the marker when using the marking jig described in Patent Document 1, resulting in the mark being drawn in an inappropriate position.

[0008] The object of the present invention is to provide a marking jig that can properly perform marking work on pipes. [Means for solving the problem]

[0009] To achieve the above objective, the invention according to claim 1 is a marking jig used for marking a pipe at a position a predetermined length away from the tip of the pipe, comprising: a cylindrical portion into which the pipe is inserted; a contact portion provided within the cylindrical portion for contacting and defining the insertion position of the tip of the pipe; and a marking hole provided at a position a predetermined length away from the contact portion toward the open end face of the cylindrical portion and penetrating the cylindrical portion, wherein the open end face of the cylindrical portion has a concave portion and a convex portion provided at different positions in the circumferential direction.

[0010] The invention according to claim 2 is a marking jig in which the circumferential length of the concave portion and the circumferential length of the convex portion are different from each other, as described in claim 1.

[0011] The invention according to claim 3 is a marking jig according to claim 1 or claim 2, wherein the bottom surface of the concave portion and / or the tip surface of the convex portion at the open end surface of the cylindrical portion are inclined surfaces that are inclined with respect to the axis of the cylindrical portion. [Effects of the Invention]

[0012] According to the above configuration, by arranging the circumferentially concave and convex portions on the open end surface of the cylindrical portion, even an operator familiar with the marking jig described in Patent Document 2 can easily notice the misuse of the marking jig (attempting or performing marking work without using the marking holes) from the non-planar appearance of the open end surface or from the non-linear discomfort caused by the uneven shape when moving the marker along the open end surface. Therefore, the marking jig of the present invention makes it possible to perform marking work on pipes appropriately. [Brief explanation of the drawing]

[0013] [Figure 1] A perspective view of the marking jig and the pipe after marking. [Figure 2] Front view of the marking jig. [Figure 3] Rear view of the marking jig. [Figure 4] Left side view of the marking jig. [Figure 5] Right side view of the marking jig. [Figure 6] Plan view of a marking jig. [Figure 7] Bottom view of the marking jig. [Figure 8] Cross-sectional view along line AA in Figure 4. [Figure 9] An example of a marking jig and a perspective view of the pipe after marking. [Figure 10] Front view of another example of a marking jig. [Figure 11] Rear view of another example of a marking jig. [Figure 12] Left side view of another example of a marking jig. [Figure 13] Right side view of another marking jig. [Figure 14] Plan view of another example of a marking jig. [Figure 15]Bottom view of a special marking jig. [Figure 16] Cross-sectional view taken along line B-B in FIG. 12.

Embodiment for Carrying out the Invention

[0014] Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. As shown in FIG. 1, the marking jig 1 of the present embodiment is used for assisting in drawing a mark 31 serving as a guide for an appropriate insertion depth into a pipe joint (not shown) with respect to the outer peripheral surface of a pipe P1 used for, for example, water supply and hot water supply pipes.

[0015] The pipe P1 is made of a synthetic resin material such as cross-linked polyethylene or polybutene. The nominal diameter (size) of the pipe P1 is "10A (for example, an outer diameter of 13.0 mm and an inner diameter of 9.8 mm)". The pipe joint (not shown) is a so-called one-touch type that can complete the connection simply by inserting the pipe P1.

[0016] On the outer peripheral surface of the pipe P1, a U-shaped mark 31 is drawn by a marker (for example, an ink pen) not shown. The mark 31 has a circumferential line 31a extending in the circumferential direction of the pipe P1 and a pair of axial lines 31b extending in the axial direction of the pipe P1. The circumferential line 31a is located at a predetermined length away from the tip of the pipe P1 in the axial direction (the vertical direction in FIG. 1) on the outer peripheral surface of the pipe P1. By using the circumferential line 31a of the mark 31 as a reference, an operator can insert and connect the pipe P1 to the pipe joint at an appropriate depth.

[0017] The axial line 31b of mark 31 is for the supervisor to check later whether the worker has performed the connection work between pipe P1 and a pipe fitting not shown without using the marking jig 1. In other words, for example, if mark 31 only has a circumferential line 31a, it is conceivable that the worker may have performed shoddy work by connecting pipe P1 and a pipe fitting not shown by relying solely on feel, without using the marking jig 1, or in other words, without drawing the circumferential line 31a, and then conveniently drawing the circumferential line 31a after the connection work to deceive the supervisor.

[0018] However, the portion of the outer surface of pipe P1 on which the axial line 31b is drawn is almost completely hidden inside the pipe joint after the connection work, making it impossible to approach and contact the marker. Therefore, unlike the circumferential line 31a, the axial line 31b must be drawn before the connection work.

[0019] In other words, the supervisor is convinced that the work of drawing the axial line 31b was performed before the connection work, based on the presence of the axial line 31b, which is slightly visible in the distance through the narrow gap near the pipe insertion hole of the pipe fitting (not shown) where the pipe P1 is inserted and connected, and also infers that the circumferential line 31a was drawn using the marking jig 1 as per the agreement.

[0020] As shown in Figure 8, the marking jig 1 of this embodiment can be used not only for marking pipe P1 of size "10A", but also for marking pipe P2 of size "13A (for example, outer diameter 17 mm, inner diameter 12.8 mm)", pipe P3 of size "16A (for example, outer diameter 21.5 mm, inner diameter 16.2 mm)", and pipe P4 of size "20A (for example, outer diameter 27.0 mm, inner diameter 20.5 mm)".

[0021] In other words, the marking jig 1 is integrally molded from a synthetic resin material such as polylactic acid or polypropylene and comprises a first cylindrical part 11 used to draw mark 31 on a pipe P1 of size "10A", a second cylindrical part 12 used to draw mark 31 on a pipe P2 of size "13A", a third cylindrical part 13 used to draw mark 31 on a pipe P3 of size "16A", and a fourth cylindrical part 14 used to draw mark 31 on a pipe P4 of size "20A".

[0022] Thus, the marking jig 1 integrates the first cylindrical part 11 to the fourth cylindrical part 14 to accommodate multiple sizes (four sizes in this embodiment) of pipes P1 to P4, eliminating the inconvenience and risk of loss associated with carrying multiple small marking jigs, for example, that are separate for each size.

[0023] As shown in Figures 1 to 8, the first cylindrical section 11 to the fourth cylindrical section 14 are each bottomed cylinders. The inner diameters of the first cylindrical section 11 to the fourth cylindrical section 14 are set according to the outer diameters of the corresponding pipes P1 (size "10A") to P4 (size "20A"). In accordance with the differences in these inner diameters, the outer diameters of the corresponding first cylindrical section 11 to the fourth cylindrical section 14 are also set to differ from each other.

[0024] The first cylindrical portion 11 and the second cylindrical portion 12, which has an inner and outer diameter slightly larger than the first cylindrical portion 11, are arranged in series so that their respective axes L coincide. The third cylindrical portion 13, which has an inner and outer diameter slightly larger than the second cylindrical portion 12, and the fourth cylindrical portion 14, which has an inner and outer diameter slightly larger than the third cylindrical portion 13, are arranged in series so that their respective axes M coincide.

[0025] The portion consisting of the first cylindrical portion 11 and the second cylindrical portion 12, and the portion consisting of the third cylindrical portion 13 and the fourth cylindrical portion 14, have the same length in the direction of axis L and axis M, and are arranged in parallel such that their respective axes L and axis M are parallel to each other. The portion consisting of the first cylindrical portion 11 and the second cylindrical portion 12, and the portion consisting of the third cylindrical portion 13 and the fourth cylindrical portion 14 are arranged such that the first cylindrical portion 11 and the fourth cylindrical portion 14 are adjacent to each other, and the second cylindrical portion 12 and the third cylindrical portion 13 are adjacent to each other.

[0026] The internal space of the portion consisting of the first cylindrical portion 11 and the second cylindrical portion 12 and the internal space of the portion consisting of the third cylindrical portion 13 and the fourth cylindrical portion 14 overlap in part and communicate with each other. By forming the portion consisting of the first cylindrical portion 11 and the second cylindrical portion 12 and the portion consisting of the third cylindrical portion 13 and the fourth cylindrical portion 14 so as to share a part of their internal space, the marking jig 1 can be made smaller in the direction intersecting the axis L and axis M, even if it is designed to accommodate multiple sizes, and the marking jig 1 becomes highly portable and easy to use.

[0027] The axis L of the portion consisting of the first cylindrical portion 11 and the second cylindrical portion 12 is located outside the internal space of the portion consisting of the third cylindrical portion 13 and the fourth cylindrical portion 14. In a front view, the width of the communication portion between the internal space of the portion consisting of the first cylindrical portion 11 and the second cylindrical portion 12 and the internal space of the portion consisting of the third cylindrical portion 13 and the fourth cylindrical portion 14 is narrower than the outer diameter of the pipe P1. Therefore, for example, it is possible to prevent the pipe P1 inserted into the first cylindrical portion 11 from shifting towards the fourth cylindrical portion 14, and the pipe P1 is stabilized in the marking jig 1.

[0028] Display sections 15 are provided on the outer circumferential surfaces of the first cylindrical section 11 to the fourth cylindrical section 14. The display section 15 of the first cylindrical section 11 displays the size of the corresponding pipe P1, "10A"; the display section 15 of the second cylindrical section 12 displays the size of the corresponding pipe P2, "13A"; the display section 15 of the third cylindrical section 13 displays the size of the corresponding pipe P3, "16A"; and the display section 15 of the fourth cylindrical section 14 displays the size of the corresponding pipe P4, "20A".

[0029] Next, the marking guide function, the oblique cut detection function, and the misuse prevention function of the marking jig 1 will be described in detail.

[0030] Since the first cylindrical section 11 to the fourth cylindrical section 14 have similar configurations for each of the functions described above, only the first cylindrical section 11 corresponding to the pipe P1 of size "10A" will be described, and the same reference numerals will be used for similar configurations in the second cylindrical section 12 to the fourth cylindrical section 14 to avoid repeated explanations. However, even if the same reference numerals are used, the dimensions, shapes, and other details of each configuration differ from one another depending on the size of the corresponding pipes P2 to P4.

[0031] As shown in Figure 8, a contact portion 16 is provided on the inner bottom surface of the first cylindrical portion 11. The tip of the pipe P1 inserted into the first cylindrical portion 11 comes into contact with the contact portion 16. This contact defines the insertion position of the tip of the pipe P1 relative to the first cylindrical portion 11.

[0032] As shown in Figure 6, the inner surface of the first cylindrical portion 11 has a plurality of protrusions 17 formed at equal intervals in the circumferential direction. The protrusions 17 provide an appropriate amount of clamping force to the outer surface of the pipe P1, thereby achieving both ease of insertion of the pipe P1 into the first cylindrical portion 11 and preventing the pipe P1 from easily coming out of the first cylindrical portion 11.

[0033] As shown in Figures 1 to 4, the first cylindrical portion 11 is provided with a rectangular inspection window 18 in a side view. The inspection window 18 is open on the outer surface of the first cylindrical portion 11 and extends through to the internal space of the first cylindrical portion 11. The inspection window 18 is positioned so that the contact portion 16 can be easily seen from the outside. Therefore, the worker can easily check the contact state between the tip of the pipe P1 inserted into the first cylindrical portion 11 and the contact portion 16 by using the inspection window 18.

[0034] As shown in Figures 1 to 8, the first cylindrical portion 11 has a U-shaped marking hole 19 that penetrates the first cylindrical portion 11 radially when viewed from the front. The inner surface of the marking hole 19 is tapered, with the width on the radially inner side being narrower than the width on the radially outer side, for example, to facilitate the insertion of a marker. When the pipe P1 is inserted into the first cylindrical portion 11, a portion of the outer surface of the pipe P1 is exposed to the outside through the marking hole 19.

[0035] The marking hole 19 has a pair of axial holes 19a that extend linearly in the axial direction from near the open end face 21 of the first cylindrical portion 11, and circumferential holes 19b that are connected perpendicularly to the axial holes 19a and extend in the circumferential direction. The circumferential holes 19b are provided at a predetermined distance (insertion depth into a pipe fitting of a size corresponding to pipe P1) from the contact portion 16.

[0036] To draw a mark 31 on pipe P1 using the marking jig 1, pipe P1 is inserted into the first cylindrical part 11 of the corresponding size. Then, with the tip of pipe P1 in contact with the contact part 16, a marker (not shown) is moved circumferentially along the circumferential hole 19b to draw a circumferential line 31a. Additionally, a pair of axial lines 31b are drawn by moving the marker axially along each axial hole 19a.

[0037] A reference mark 20 is provided on the first cylindrical portion 11. The reference mark 20 is used to determine whether the oblique cut is excessive on the end face of the pipe P1, which can be seen through the inspection window 18, based on its relative position to the end face of the pipe P1. The reference mark 20 is provided by forming axial steps on both wall surfaces located at the front and rear in the circumferential direction on the inner surface of the inspection window 18.

[0038] Therefore, when the end face of pipe P1 and the contact portion 16 are in contact, by checking the contact portion through the confirmation window 18, it is possible to determine whether or not the oblique cut of the end face of pipe P1 is excessive based on the relative positional relationship between the end face of pipe P1 and the reference mark 20.

[0039] The open end face 21 of the first cylindrical portion 11 has concave portions 22 and convex portions 23 provided at different positions in the circumferential direction, and the open end face 21 is not composed of a single plane. Multiple concave portions 22 and convex portions 23 are arranged alternately in the circumferential direction (in this embodiment, there are three concave portions 22 and four convex portions 23).

[0040] Thus, by shaping the opening end face 21 of the first cylindrical portion 11 with a concave portion 22 and a convex portion 23 arranged in the circumferential direction, even an operator familiar with the marking jig (not shown) described in Patent Document 2 can easily notice the misuse of the marking jig 1 (attempting or performing marking work without using the marking hole 19) from the non-planar appearance of the opening end face 21, or from the non-linear discomfort caused by the uneven shape felt when moving the marker along the opening end face 21. Therefore, the marking jig 1 allows for proper marking work on the pipe P1.

[0041] At the open end face 21 of the first cylindrical portion 11, the circumferential length of the concave portion 22 and the circumferential length of the convex portion 23 are different. In particular, the convex portion 23 is longer in the circumferential direction than the concave portion 22, and some convex portions 23 are more than 1.5 times longer than the concave portion 22. Therefore, the non-planar appearance of the open end face 21 is emphasized, and the non-linear discomfort caused by the uneven shape when moving the marker along the open end face 21 is also increased, making it easier to notice misuse of the marking jig 1.

[0042] At the open end face 21 of the first cylindrical portion 11, the bottom surface of the concave portion 22 and the tip surface of the convex portion 23 are inclined surfaces that are tilted radially inward with respect to the axis L of the first cylindrical portion 11. Therefore, the non-planar appearance of the open end face 21 is further emphasized, and the sense of incongruity when moving the marker along the open end face 21 is also increased, making it very easy to notice misuse of the marking jig 1.

[0043] <Variation> Furthermore, the present invention can also be implemented in the following embodiments, for example. ○For example, as shown in the alternative marking jig 2 in Figures 9 to 16, the axial hole 19a is removed from the marking hole 19, and the marking hole 19 is composed only of the circumferential hole 19b.

[0044] The marking jig 1 is not limited to supporting four different sizes of pipes P1 through P4, but may support one, two, three, five, or six different sizes of pipes.

[0045] For example, Figures 9 to 16 show a marking jig 2 in which the first cylindrical part 11 corresponding to the size "10A" pipe P1 is removed from the marking jig 1. In other words, the marking jig 2 is made up of a second cylindrical part 12 corresponding to the size "13A" pipe P2, a third cylindrical part 13 corresponding to the size "16A" pipe P3, and a fourth cylindrical part 14 corresponding to the size "20A" pipe P4, and is used to mark three different sizes of pipes P2 to P4.

[0046] ○For example, as shown in the alternative examples in Figures 9 to 16, the multiple cylindrical parts (in the alternative examples, the second cylindrical part 12 to the fourth cylindrical part 14) are arranged so that their relative axes (in the alternative examples, the axis L of the second cylindrical part 12, the axis M of the third cylindrical part 13, and the axis N of the fourth cylindrical part 14) do not coincide.

[0047] In this case, for example as shown in the alternative example, the axes of the multiple cylindrical parts (in the alternative example, the second cylindrical part 12 to the fourth cylindrical part 14) may be configured such that their mutual axes (in the alternative example, the axis L of the second cylindrical part 12, the axis M of the third cylindrical part 13, and the axis N of the fourth cylindrical part 14) lie on the same virtual plane, or the axes of the multiple cylindrical parts may be configured such that not all of their mutual axes lie on the same virtual plane.

[0048] ○ The bottom surface of the concave portion 22 and the tip surface of the convex portion 23 are made inclined surfaces.

[0049] The bottom surface of the concave portion 22 and / or the tip surface of the convex portion 23 shall be inclined surfaces that slope radially outward.

[0050] <Note> The technical concept that can be understood from the above embodiment is as follows: A marking jig used for marking a pipe at a position a predetermined length away from the tip of the pipe, comprising: a cylindrical portion into which the pipe is inserted; a contact portion provided inside the cylindrical portion for contacting and defining the insertion position of the tip of the pipe; and a marking hole provided at a position a predetermined length away from the contact portion toward the open end face of the cylindrical portion and penetrating the cylindrical portion, wherein the open end face of the cylindrical portion is not a single plane. [Explanation of Symbols]

[0051] 1…Marking jig, 2…Marking jig (another example). 11...First cylindrical part, 12...Second cylindrical part, 13...Third cylindrical part, 14...Fourth cylindrical part, 15...Display part, 16...Contact part, 17...Protrusion, 18...Confirmation window, 19...Marking hole (a...Axial hole, b...Circumferential hole). 20...Reference mark, 21...Open end face, 22...Concave part, 23...Convex part. 31... Mark (a... circumferential line, b... axial line). P1...Pipe, P2...Pipe, P3...Pipe, P4...Pipe. L...Axis line, M...Axis line, N...Axis line.

Claims

1. A marking jig used to mark a pipe at a predetermined distance from the tip of the pipe, The cylindrical portion into which the aforementioned pipe is inserted, A contact portion provided within the cylindrical portion, which defines the insertion position of the tip of the pipe, It comprises a marking hole that penetrates the cylindrical portion and is provided at a predetermined distance from the contact portion toward the open end face side of the cylindrical portion, A marking jig having a concave portion and a convex portion at different positions in the circumferential direction on the open end surface of the cylindrical portion.

2. The marking jig according to claim 1, wherein the circumferential length of the concave portion and the circumferential length of the convex portion are different from each other.

3. The marking jig according to claim 1 or claim 2, wherein the bottom surface of the concave portion and / or the tip surface of the convex portion at the open end surface of the cylindrical portion are inclined surfaces that are inclined with respect to the axis of the cylindrical portion.

Images