JP7839680B2 - Pipe fitting detachment jig, pipe fitting, and method for detaching male and female fittings - Google Patents

Description

This invention relates to a pipe fitting release tool, a pipe fitting, and a method for releasing a male and female fitting, and more particularly to a pipe fitting release tool, a pipe fitting, and a method for releasing a male and female fitting that allows for easy disengagement of the male and female fittings.

Conventionally, pipe fittings are known to include a female fitting having a circumferential groove and a recess on its inner surface, a male fitting having a circumferential groove on the outer surface of a shaft portion inserted into the female fitting, an expandable and contractible elastic ring body housed in the circumferential groove of the female fitting, and a retainer having a short cylindrical body and a long cylindrical body that are inserted into the female fitting and expand the elastic ring body (see Patent Document 1). Such conventional pipe fittings have a configuration in which the long cylindrical body provided on the retainer is pre-slidably fitted onto the female fitting, and the male and female fittings can be disengaged by the retainer, which is irremovably attached to the female fitting, and this disengagement can be performed without using a separate tool.

Specifically, during engagement, the inner circumference of the elastic ring body fitted into the circumferential groove of the female joint is in contact with the circumferential groove on the outer surface of the male joint shaft, and the outer circumference of the elastic ring body is in contact with the recess of the female joint. In this state, the elastic ring body is pressed against the circumferential groove of the male joint within the recess, that is, the male joint is prevented from coming loose.

The short cylindrical body of the retainer fits between the shaft of the male joint and the inner circumferential surface of the female joint, facing the elastic ring body in the axial direction. This short cylindrical body is movable relative to the female joint between the engaged and disengaged positions. In the engaged position, the short cylindrical body is separated from the elastic ring body; in the disengaged position, the short cylindrical body moves the elastic ring body into the circumferential groove provided on the inner circumferential surface of the female joint.

When the male connector is inserted into the female connector and fluid pressure is applied, the elastic ring body comes into contact with the recessed portion.

During disengagement, the retainer, which is permanently attached to the female fitting, moves axially within the female fitting, and the short cylindrical body of the retainer pushes the elastic ring body into the circumferential groove of the female fitting. This expands the diameter of the elastic ring body, disengaging the female fitting from the male fitting.

Japanese Utility Model Publication No. 5-54891

As described above, the pipe fitting described in Patent Document 1 had a structure that allowed the male and female fittings to be engaged without tools, and also allowed them to be disengaged without tools by a retainer pre-installed on the female fitting. However, in conventional pipe fittings, when engaged, for example, when a vibration load is applied to the retainer on the exterior, and the vibration load is applied to the elastic ring body via the retainer, it was necessary to make the diameter of the elastic ring body larger and give the elastic ring body a strong expanding force so that the male and female fittings would not be easily disengaged. Therefore, a strong force is required to move the retainer on the female fitting to the disengagement position and expand the diameter of the elastic ring body. Thus, when disengaging the female and male fittings, it was necessary to press the tip of the female fitting where the retainer is located with a strong force, making the disengagement process difficult.

Furthermore, because the long cylindrical part of the retaining device, which is the primary pressing component, covers the outer circumference of the female fitting, there was a risk of accidental impact to the cylindrical part during transport or connection work, potentially causing damage. If damaged, the engagement cannot be released, rendering the pipe fitting unusable.

Therefore, the present invention aims to provide a pipe fitting release tool, a pipe fitting, and a method for releasing a male and female fitting, which improve the workability of releasing the engagement between the male and female fittings and prevent situations where release becomes impossible.

The pipe joint release tool of this invention is used for a pipe joint comprising a male joint with a shaft portion and a female joint that can engage with the male joint by fitting the shaft insertion portion of the male joint along the axial direction of the female joint side, thereby allowing a locking member provided on the shaft insertion portion to enter a locking groove provided on the shaft portion. The tool comprises a gripping portion that is detachably mounted between the engaged male and female joints, and a thin cylindrical body provided on the gripping portion. The thin cylindrical body releases the engagement between the male and female joints by moving the gripping portion mounted on the pipe joint in the axial direction of the female joint side, thereby releasing the locking member from the locking groove.

The pipe joint of this invention comprises a male joint provided with a shaft portion, and a female joint whose shaft insertion portion is fitted to the shaft portion along the axial direction of the female joint, thereby allowing a locking member provided on the shaft insertion portion to engage with the male joint by engaging with a locking groove provided on the shaft portion. The shaft portion of the male joint has a gripping portion of a pipe joint release jig, separate from the male and female joints, detachably attached, and the gripping portion is configured to move axially towards the female joint. In the engaged state, when the gripping portion attached to the shaft portion moves axially towards the female joint, a gap is formed between the shaft portion and the shaft insertion portion, allowing a thin cylindrical body provided on the gripping portion to enter. The thin cylindrical body disengages the locking member from the locking groove, releasing the engagement between the male and female joints.

The present invention provides a method for detaching a male and female pipe joint, comprising: a male joint having a shaft portion; and a female joint having a shaft insertion portion that is fitted to the shaft portion along the axial direction of the female joint, thereby allowing a locking member provided on the shaft insertion portion to engage with the male joint by entering a locking groove provided on the shaft portion. The method comprises: a preparation step of preparing a pipe joint detachment jig having a thin cylindrical body on its gripping portion; a mounting step of detachably attaching the gripping portion of the pipe joint detachment jig to the shaft portion of the male joint engaged with the shaft insertion portion of the female joint; and a release step of moving the gripping portion attached to the shaft portion along the axial direction of the female joint, causing the thin cylindrical body of the pipe joint detachment jig to enter the gap between the shaft portion and the shaft insertion portion, thereby disengaging the locking member from the locking groove and releasing the engagement between the male and female joints.

This invention provides a pipe fitting release tool comprising a gripping portion detachably mounted between a male and female fitting in an engaged state, and a thin cylindrical body provided on the gripping portion. The thin cylindrical body releases the locking member from the locking groove by moving the gripping portion mounted on the pipe fitting axially toward the female fitting, thereby releasing the engagement between the male and female fittings. Therefore, unlike conventional methods, there is no need to forcefully press the tip of the female fitting. Since the female and male fittings can be released using a pipe fitting release tool prepared separately from the female fitting, the workability of releasing the engagement between the female and male fittings can be improved. Furthermore, since the pipe fitting release tool can be removed from the pipe fitting when not in use, it is possible to prevent the engagement from becoming impossible due to damage, as has been the case with conventional methods.

According to this invention, the pipe fitting eliminates the need to apply strong force to the tip of the female fitting, as in conventional designs. The female fitting and male fitting can be disengaged using a separate pipe fitting disengagement tool, thus improving the efficiency of disengaging the female and male fittings. Furthermore, since the pipe fitting disengagement tool can be removed from the pipe fitting when not in use, damage that could render disengagement impossible can be prevented.

According to the method for disengaging male and female fittings of this invention, it is not necessary to press the tip of the female fitting with strong force as in conventional methods. Since the female and male fittings can be disengaged using a separate pipe fitting disengagement jig, the workability of disengaging the female and male fittings can be improved. Furthermore, since the pipe fitting disengagement jig can be removed from the pipe fitting when not in use, damage that could render disengagement impossible can be prevented.

This is a perspective view showing a pipe joint device, which is one embodiment of the present invention. This is a cross-sectional view showing the male joint. This is a perspective view showing a female connector. This is a cross-sectional view showing a female connector. This is a cross-sectional view from one side showing the second pipe attached to the female fitting. This is a perspective view showing the detachment jig. This is a one-sided cross-sectional view of a pipe joint device, showing it with the detachment jig attached. This is a cross-sectional view showing the male and female fittings engaged. This is a one-sided cross-sectional view of a pipe joint device, showing the detachment jig in the pressed position. This is a one-sided cross-sectional view of a pipe joint device, showing the male joint in the withdrawn position. This is a plan view showing an elastic ring body.

The following describes specific embodiments of the present invention in detail with reference to the drawings. Figure 1 shows a pipe joint device, which is one embodiment of the present invention. The pipe joint device 9 is used, for example, in piping for transporting temperature-controlled water in fan coil units that control the air conditioning of a building, or in piping for transporting oil to control the pilot operation of construction machinery.

As shown in Figure 1, the pipe joint device 9 consists of a pipe joint 10 comprising a male joint 11 and a female joint 12, and a pipe joint detachment jig (hereinafter simply referred to as "detachment jig") 13. The male joint 11 has a shaft portion 14, an outer circumferential groove portion 15, and a mounting shaft portion 16, and a first pipe portion 17 through which fluid flows is formed inside the male joint 11.

As shown in Figure 2, the shaft portion 14 is the part inserted toward the female fitting 12. It has, in order from the insertion side, a first shaft diameter portion 18 and a second shaft diameter portion 19, which is larger in diameter than the first shaft diameter portion 18. A first tapered diameter portion 20 is formed between the first shaft diameter portion 18 and the second shaft diameter portion 19. The outer circumferential groove portion 15 is formed on the outer circumference of the second shaft diameter portion 19.

On the axial A side (hereinafter simply referred to as "axial A") of the female joint 12 relative to the outer circumferential groove 15, a flat diameter portion 21 is provided. Furthermore, a first axial diameter portion 18, smaller in diameter than the flat diameter portion 21, is adjacent to the flat diameter portion 21 in the axial A direction. The mounting shaft portion 16 of the male joint 11, located at the end opposite to the axial A direction relative to the shaft portion 14, has, for example, a threaded portion (not shown) on its outer circumferential surface, to which the device 22 is screwed and attached.

As shown in Figure 3, the female connector 12 has a shaft insertion portion 24, an elastic ring body 25 housed in the shaft insertion portion 24, and an O-ring 26. The elastic ring body 25 has a C-shaped cross-section with gaps at both ends of its arc shape. This elastic ring body 25 corresponds to the locking member of this invention. The O-ring 26 is made of a material such as rubber and is annular in shape.

As shown in Figure 4, the shaft insertion section 24 has a shallow inner circumferential groove 28, a deep inner circumferential groove 29, and an O-ring mounting groove 30 formed sequentially along the axial direction A. The shaft insertion section 24 has a first hole 32 for receiving the shaft 14, a second hole 33 with a smaller diameter than the first hole 32, and a third hole 34 with a smaller diameter than the second hole 33, all formed sequentially along the axial direction A. A second tapered diameter section 35 is formed between the first hole 32 and the second hole 33. The first hole 32, the second hole 33, and the third hole 34 constitute a second pipe section 36 for fluid transfer. The second tapered diameter section 35 prevents further insertion of the male coupling 11 by contacting the first tapered diameter section 20 during engagement. The third hole 34 has the same diameter as the first pipe section 17.

A shallow inner circumferential groove 28 and a deep inner circumferential groove 29 are formed sequentially along the axial direction A, and the shallow inner circumferential groove 28 and the deep inner circumferential groove 29 are connected, with the inner wall of the deep inner circumferential groove 29 on the side opposite to the axial direction A being absent. In other words, the elastic ring body 25 housed in the deep inner circumferential groove 29 is movable between the shallow inner circumferential groove 28 and the deep inner circumferential groove 29. The shallow inner circumferential groove 28 holds the elastic ring body 25 between its bottom and the bottom of the outer circumferential groove 15 of the male joint 11 in the radial direction of the second pipe section 36 (first pipe section 17), thereby maintaining the engagement (hereinafter simply referred to as "engagement") between the male joint 11 and the female joint 12. To ensure the engagement is maintained, the elastic ring body 25 is designed so that its inner diameter in its natural state is smaller than the outer diameter of the second diameter portion 19 of the shaft 14 (see Figure 2), and its thickness is smaller than the width of the shallow inner groove portion 28. In other words, the outer groove portion 15 is set to a depth of approximately one-third of the wire diameter of the elastic ring body 25, and the elastic ring body 25 is designed so that its inner diameter in its natural state coincides with the bottom of the outer groove portion 15 (see Figure 2). The outer groove portion 15 provided on the outer circumference of the second diameter portion 19 of the shaft 14 and the shallow inner groove portion 28 provided in the shaft insertion portion 24 correspond to the locking grooves of this invention.

The second hole 33 has an O-ring mounting groove 30 into which an O-ring 26 is fitted. When engaged, the O-ring 26 contacts the outer circumference of the first diameter portion 18 of the male joint 11, maintaining a watertight seal between the first pipe portion 17 and the second pipe portion 36.

As shown in Figure 5, the outer circumference of the pipe insertion section 39 is initially crimped on a portion of the cylindrical body 38. After inserting the pipe 37 between the pipe insertion section 39 and the cylindrical body 38, the entire cylindrical body 38 is crimped to firmly secure the pipe 37 to the pipe insertion section 39.

As shown in Figure 6, the release jig 13 is used to release the engagement and has a thick, annular gripping portion 42 and a ring-shaped thin cylindrical body 43 provided in the center of the gripping portion 42. As also shown in Figure 1, the gripping portion 42 and the thin cylindrical body 43 can be divided into two halves, left and right, from a dividing line 45 that extends radially from the rotation axis 44 provided in the gripping portion 42. In other words, the gripping portion 42 is composed of a right gripping portion 42a and a left gripping portion 42b, and the thin cylindrical body 43 is also composed of a right thin cylindrical body 43a and a left thin cylindrical body 43b. For the sake of explanation, the first gripping portion half on the right side in Figure 6 will be referred to as the right gripping portion 42a, and the second gripping portion half on the left side in Figure 6 will be referred to as the left gripping portion 42b. Furthermore, for the sake of clarity, the first thin cylindrical half on the right side of Figure 6 will be referred to as the right thin cylindrical half 43a, and the second thin cylindrical half on the left side of Figure 6 will be referred to as the left thin cylindrical half 43b.

The right gripping portion 42a and the left gripping portion 42b each have a thin, semi-annular semi-bottom plate portion 422 and a semi-outer wall portion 423 that is erected along the outer peripheral edge of the semi-bottom plate portion 422 and curved in an arc. A semi-cylindrical right thin cylindrical body 43a, curved in an arc along the inner peripheral edge of the semi-bottom plate portion 422, is erected on the right gripping portion 42a, and a semi-cylindrical left thin cylindrical body 43b, curved in an arc along the inner peripheral edge of the semi-bottom plate portion 422, is erected on the left gripping portion 42b.

In this embodiment, the length of the semi-outer wall portion 423 in the axial direction of the gripping portion 42 is longer than the lengths of the right thin cylindrical body 43a and the left thin cylindrical body 43b in the axial direction of the gripping portion 42, and is formed to protrude. In this embodiment, when the detachment jig 13 is attached to the pipe joint 10, the axial direction of the gripping portion 42 coincides with the axial direction A of the female joint 12, so the axial direction of the detachment jig 13 will hereinafter also be referred to as axial direction A. In this case, the ends of the semi-outer wall portion 423 and the right thin cylindrical body 43a and the left thin cylindrical body 43b that are positioned on the side opposite to axial direction A are flat (see Figure 1). The tips of the right thin cylindrical body 43a and the left thin cylindrical body 43b are formed in a non-protruding state, recessed in the axial direction relative to the tip of the semi-outer wall portion 423 of the gripping portion 42. As a result, the right thin cylindrical body 43a and the left thin cylindrical body 43b are protected by the semi-outer wall portion 423 provided on the outer circumference of the right thin cylindrical body 43a and the left thin cylindrical body 43b, preventing damage to the right thin cylindrical body 43a and the left thin cylindrical body 43b.

The rotating shaft 44 is positioned axially parallel to the axial direction A of the release jig 13, and rotatably connects one end of the right gripping portion 42a to one end of the left gripping portion 42b. The right gripping portion 42a and the left gripping portion 42b rotate around the rotating shaft 44 in a direction where the other end of the right gripping portion 42a and the other end of the left gripping portion 42b move away from each other, resulting in an open state. In the open state, the right gripping portion 42a and the left gripping portion 42b rotate around the rotating shaft 44 in a direction where the other end of the right gripping portion 42a and the other end of the left gripping portion 42b move towards each other, until the other end of the right gripping portion 42a and the other end of the left gripping portion 42b come into contact, resulting in a closed state. In other words, the release jig 13 is rotatable around the rotating shaft 44 between the open state and the closed state. When the right gripping portion 42a and the left gripping portion 42b of the detachment jig 13 are closed, the right thin cylindrical body 43a and the left thin cylindrical body 43b form an annular hole. When the right gripping portion 42a and the left gripping portion 42b are opened, the detachment jig 13 has a configuration that allows it to clamp the outer circumferential surface of the second diameter portion 19 of the shaft portion 14 of the male joint 11, which connects the detachment jig 13 to the female joint 12, between the right thin cylindrical body 43a and the left thin cylindrical body 43b.

The detachment jig 13, with the shaft portion 14 positioned between the right thin cylindrical body 43a and the left thin cylindrical body 43b, closes the right gripping portion 42a and the left gripping portion 42b from an open state, forming a hole for gripping the portion of the second diameter portion 19 of the shaft portion 14 that is not inserted into the female joint 12, using the inner circumferential surfaces 46 of the right thin cylindrical body 43a and the left thin cylindrical body 43b. In other words, the right thin cylindrical body 43a and the left thin cylindrical body 43b form a cylindrical thin cylindrical body 43 when the right gripping portion 42a and the left gripping portion 42b close, and the thin cylindrical body 43 grips the outer circumferential surface 46 of the portion of the second diameter portion 19 of the shaft portion 14 of the male joint 11 connected to the female joint 12 that is exposed to the outside and not inserted into the female joint 12. The rotating shaft 44 shown in the figure is, for example, a screw. For example, in the case of a screw, the threaded tip is screwed to the left gripping portion 42b, and the unthreaded portion between the screw head and the screw rotatably supports the right gripping portion 42a.

As shown in Figure 7, the thin cylindrical body 43 is attached to the outer circumferential surface of the second diameter portion 19 of the shaft portion 14 of the male joint 11, which is exposed to the outside, in the pipe joint 10 connecting the male joint 11 and the female joint 12. The thin cylindrical body 43 is thin enough to fit into the gap formed between the second diameter portion 19 of the shaft portion 14 and the shaft insertion portion 24 when the male joint 11 and the female joint 12 are engaged. Disengagement is performed by pushing the release jig 13 in the axial direction A. At this time, the thin cylindrical body 43 fits into the gap between the shaft portion 14 and the shaft insertion portion 24, pushing the elastic ring body 25 from the shallow inner groove portion 28 towards the deep inner groove portion 29. At this time, the inner circumference of the elastic ring body 25 contacts the diameter portion 21 of the shaft portion 14, which has a flat outer circumferential surface and is located on the axial direction A side relative to the outer circumferential groove portion 15.

In this embodiment, as shown in Figure 2, if the outer diameter at the diameter portion 21 is d4, the outer diameter at the bottom of the outer peripheral groove portion 15 is d5, the wire diameter of the elastic ring body 25 is d, and the wire diameter of the elastic ring body 25 (d/3) is positioned within the outer peripheral groove portion 15 as shown in region ER in Figure 2, then the relationship shown in the following equation (1) exists.
d5 = d4 - (2・( d /3)) ... (1)

Furthermore, in this embodiment, the outer diameter of the second shaft diameter portion 19 and the outer diameter of the diameter portion 21 are formed to be substantially the same. Here, "substantially the same" includes not only cases where the outer diameters of the second shaft diameter portion 19 and the diameter portion 21 are completely identical, but also cases where they are formed with a deviation of a degree that allows for the engagement of the male joint 11 and the female joint 12, and the disengagement function of the disengagement jig 13, to be realized.

Next, the operation of the above configuration will be explained. In the initial state of the female joint 12, the elastic ring body 25 is housed in the deep inner circumferential groove 29. In this state, the male joint 11 is inserted into the female joint 12. Insertion involves fitting the shaft portion 14 and the shaft insertion portion 24 together along the axial direction A on the female joint 12 side. As a result, the first diameter portion 18 of the shaft enters the second hole portion 33, which is slightly larger in diameter, and the first tapered diameter portion 20 on the shaft portion 14 comes into contact with the second tapered diameter portion 35 on the shaft insertion portion 24. This stops the insertion of the male joint 11, so the end of engagement can be known. At this time, the inner circumference of the elastic ring body 25 is in a state where it is entered into the outer circumferential groove 15 just before the first tapered diameter portion 20 comes into contact with the second tapered diameter portion 35. The O-ring 26 is in contact with the first diameter portion 18 of the shaft, making the gap between the shaft portion 14 and the shaft insertion portion 24 watertight. This allows the fluid to begin moving.

When fluid movement begins, the fluid pressure between the shaft portion 14 and the shaft insertion portion 24 biases the male joint 11 and the female joint 12 toward separation. As a result, as shown in Figure 8, the male joint 11 is pushed in the direction opposite to the axial direction A, and the elastic ring body 25 moves to the shallow inner groove portion 28 while it is engaged in the outer groove portion 15. This causes the elastic ring body 25's outer diameter to be restricted by the shallow inner groove portion 28, preventing further expansion, and its inner diameter to be pressed against the outer groove portion 15. This prevents the male joint 11 from moving toward the female joint 12, thus resulting in a strong engagement between the male joint 11 and the female joint 12. Note that the piping 37 is omitted in the figure.

Next, when disengaging, a detachment jig 13 is prepared, which has a thin cylindrical body 43 attached to the gripping portion 42 (corresponding to the "preparation step" of the present invention). Then, the gripping portion 42 of the detachment jig 13 is detachably attached to the shaft portion 14 of the male joint 11 that is engaged with the shaft insertion portion 24 of the female joint 12 (corresponding to the "attachment step" of the present invention). In other words, after stopping the fluid flow, the gripping portion 42 of the detachment jig 13 is held and, as shown in Figure 1, the detachment jig 13 is divided into left and right halves around the rotating shaft 44, opening the right gripping portion 42a and the left gripping portion 42b. After opening the right gripping portion 42a and the left gripping portion 42b, the right gripping portion 42a and the left gripping portion 42b are closed, and the thin cylindrical body 43 is inserted into the gap between the male joint 11 and the female joint 12. As a result, as shown in Figure 7, the inner circumferential surface 46 of the thin cylindrical body 43 is positioned on the outer circumferential surface of the second diameter portion 19 of the male joint 11.

Subsequently, by moving the gripping portion 42 of the release jig 13 axially A, the thin cylindrical body 43 enters the gap between the second diameter portion 19 of the shaft and the shaft insertion portion 24. The thin cylindrical body 43 then disengages the locking member from the locking groove, releasing the engagement between the male joint 11 and the female joint 12 (corresponding to the "release step" of the present invention). The locking member is an elastic ring body 25 fitted into a deep inner circumferential groove 29 provided in the shaft insertion portion 24. The locking groove consists of an outer circumferential groove 15 provided in the shaft portion 14 and a shallow inner circumferential groove 28 provided in the shaft insertion portion 24.

In other words, when the release jig 13 is pushed in the axial direction A, the thin cylindrical body 43 moves along the outer circumferential surface of the second diameter portion 19 of the shaft and enters the gap between the shaft portion 14 and the shaft insertion portion 24. Further pushing causes the axial end of the thin cylindrical body 43 on the axial direction A to contact the elastic ring body 25. Then, the elastic ring body 25, with its inner circumference still inside the outer circumferential groove portion 15, is pushed together with the male joint 11 in the axial direction A. As a result, as shown in Figure 9, the outer circumference of the elastic ring body 25 faces the deep inner circumferential groove portion 29 in the radial direction of the first pipe portion 17.

Subsequently, when the male connector 11 is withdrawn from the female connector 12, the shaft portion 14 attempts to move in the direction opposite to the axial direction A. At this time, because the elastic ring body 25 is in contact with the thin cylindrical body 43, the elastic ring body 25 expands in diameter and escapes from the outer peripheral groove portion 15, resulting in the inner circumference of the elastic ring body 25 contacting the flat diameter portion 21, as shown in Figure 10. Since the wire diameter of the elastic ring body 25 is smaller than conventional designs, less force is required to expand it, thus making the disengagement process easier.

Furthermore, at this time, the elastic ring body 25 moves to a position where its outer circumference faces the deep inner groove 29 in the radial direction of the first pipe portion 17, and the outer circumference on the direction A side abuts against the inner wall of the deep inner groove 29, preventing further movement within the shaft insertion portion 24. If the male joint 11 is continued to be withdrawn, the inner circumference of the elastic ring body 25 moves from the flat diameter portion 21 to the outer surface of the first shaft diameter portion 18, which has a smaller diameter than the flat diameter portion 21. At this point, the elastic ring body 25 returns to its natural state within the deep inner groove 29 and becomes housed within the deep inner groove 29. After this, the male joint 11 can be easily withdrawn. Note that in Figures 5, 7, 8, 9, and 10, the threaded portion formed on the outer surface of the mounting shaft portion 16 is omitted from the illustration.

In this configuration, unlike conventional pipe fittings, there is no need to apply strong force to the tip of the female fitting. The male fitting 11 and female fitting 12 can be disengaged using a separate disengagement jig 13, thus improving the efficiency of disengaging the male fitting 11 and female fitting 12. Furthermore, since the disengagement jig 13 can be removed from the pipe fitting 10 when not disengaging, damage to the disengagement jig 13 during engagement of the male fitting 11 and female fitting 12 can be prevented, thus preventing disengagement from becoming impossible.

The strength (P) of the elastic ring body 25 is determined. The elastic ring body 25 has the shape shown in Figure 11. The strain (σ) of the arc-shaped spring is used to determine the strength (P) of the elastic ring body 25 using the formula shown in equation (2) below. The strength (P) is the diameter expansion force of the elastic ring body 25 and is a value related to the ease of disengaging the male joint 11 and the female joint 12.

…(2)

Since this formula is used to determine the strain (σ) of the elastic ring body 25, transforming it into a formula to determine the expanding force (P) yields the following formula (3) as the strain formula for the arc-shaped spring.

…(3)

Here, in equation (2) above, α is the central angle of the segmented portion, and since the elastic ring body 25 used has an extremely small segmented angle, almost equal to zero, we assume α ≈ 0. Also, E is the material modulus, and here we consider it to be [E = 21000 Kgf/mm2] (SUS304). Note that [mm2] is mm squared, representing square millimeters. r is the inner diameter of the elastic ring body 25 at its maximum expansion (d4/2), d is the wire diameter of the elastic ring body 25, d4 is the diameter of the male joint 11 at the diameter portion 21, and d5 is the diameter of the outer groove portion 15 at the bottom of the groove. If the relationship shown in equation (1) above exists, the strain (σ) of the elastic ring body 25 is [d/3 × π]. The inner diameter shown in [Table 1] below is the diameter of the male joint 11 at the diameter portion 21 (d4), and the wire diameter (d) is the wire diameter of the elastic ring body 25. Here, the inner diameters 1 to 3 of the diameter portion 21 were arbitrarily selected from the range of 8.0 mm to 18.0 mm, with inner diameter 1 < inner diameter 2 < inner diameter 3. Also, the wire diameters 1 to 3 of the elastic ring body 25 were arbitrarily selected from the range of 0.5 mm to 2.0 mm, with wire diameter 1 < wire diameter 2 < wire diameter 3. Then, the expansion force (P) of the elastic ring body 25 was calculated based on the arbitrarily selected inner diameters 1 to 3 and wire diameters 1 to 3 using the above formula (3), and the results shown in [Table 1] below were obtained.

In conventional pipe fittings (see Patent Document 1) where engagement can be released by a retainer pre-installed on the female fitting in an inseparable state, without using a separate release jig 13, for example, as shown in [Table 1], when using an elastic ring body 25 with an expanding force (P) of 0.42 kgf and an elastic ring body 25 with an expanding force (P) of 0.46 kgf, the engagement between the male and female fittings is released too easily. This leads to a problem where, during actual use, vibration loads are applied to the retainer of the female fitting, causing vibration loads to be transferred from the external retainer to the elastic ring body 25, resulting in the male and female fittings becoming detached. Therefore, in conventional pipe fittings, it is desirable to use an elastic ring body 25 with an expanding force (P) exceeding 0.92 kgf, as shown in [Table 1].

In contrast, the pipe joint 10 according to this embodiment does not have a retainer on the tip of the female joint 12 that allows the elastic ring body 25 to be disengaged from the outside, as in conventional designs. Since the detachment jig 13 is removed during actual use, no vibration load is applied to the elastic ring body 25 from the outside even during actual use. Therefore, the pipe joint 10 according to this embodiment eliminates concerns about detachment due to vibration load during actual use. Thus, because the pipe joint 10 according to this embodiment lacks a conventional retainer and has a structure that makes it difficult for the male joint 11 and female joint 12 to detach, it can be used with elastic ring bodies 25 with extremely small expansion forces (P), such as 0.42 kgf or 0.46 kg, which could not be used in conventional pipe joints. Therefore, the pipe joint 10 according to this embodiment can also be used with elastic ring bodies 25 with expansion forces (P) between 0.42 kgf and 0.92 kgf, which are difficult to use in conventional pipe joints.

Furthermore, in conventional pipe fittings, when using elastic ring bodies 25 with an expansion force (P) of 2.28 kgf and elastic ring bodies 25 with an expansion force (P) of 2.24 kgf, it is difficult to apply external force to the retainer provided at the tip of the female fitting. Therefore, disengaging the elastic ring body 25 by the retainer is difficult, making it unsuitable for work. For this reason, it is desirable to use elastic ring bodies 25 with an expansion force (P) of approximately 2.0 kgf or less in conventional pipe fittings.

In this embodiment of the pipe joint 10, if an elastic ring body 25 with an expanding force (P) of 2.24 kgf is used, it is difficult to disengage the male joint 11 and the female joint 12 even when using a disengagement jig 13 prepared separately from the female joint 12. Therefore, it is desirable to use an elastic ring body 25 with an expanding force (P) of approximately 2.0 kgf or less.

Therefore, in the pipe joint 10 according to this embodiment, the concern of detachment due to vibration load during actual use is eliminated, allowing the use of elastic ring bodies 25 with small expansion force (P), and enabling the use of a wide range of elastic ring bodies 25 with expansion force (P) of 0.42 kgf to 2.0 kgf. Furthermore, in the pipe joint 10 according to this embodiment, it is desirable to set the expansion force (P) of the elastic ring body 25 to 0.42 kgf to 0.92 kgf, which further facilitates the disengagement of the male joint 11 and the female joint 12.

9...Pipe joint device 10...Pipe joint 11...Male joint 12...Female joint 13...Detachment jig for pipe joint 14...Shaft portion 15...Outer circumference groove portion 19...Second diameter portion of shaft 24...Shaft insertion portion 25...Elastic ring body 28...Shallow inner circumference groove portion 29...Deep inner circumference groove portion 38...Cylindrical body 42...Gripping portion 43...Thin cylindrical body 45...Dividing line 46...Inner circumference

Claims (12)

A pipe joint release tool used in a pipe joint comprising a male joint having a shaft portion, and a female joint in which a locking member provided on the shaft portion engages with the male joint by fitting the shaft insertion portion of the male joint along the axial direction on the female joint side, thereby engaging the male joint with the locking member provided on the shaft insertion portion by engaging with the locking groove provided on the shaft portion,
The locking member is an elastic ring body,
The expansion force (P) of the elastic ring body, calculated using the strain formula for the arc-shaped spring, is between 0.42 kgf and 0.92 kgf.
In the strain formula for the arc-shaped spring, the wire diameter of the elastic ring body is a value arbitrarily selected from the range of 0.5 mm to 2.0 mm.
The aforementioned pipe fitting detachment jig is,
It comprises a gripping portion that is detachably attached between the male and female joints in an engaged state, and a thin cylindrical body provided on the gripping portion,
The thin cylindrical body is a pipe fitting release jig that releases the engagement between the male fitting and the female fitting by moving the gripping portion attached to the pipe fitting in the axial direction toward the female fitting, thereby disengaging the locking member from the locking groove. A pipe joint release tool used in a pipe joint comprising a male joint having a shaft portion, and a female joint in which a locking member provided on the shaft portion engages with the male joint by fitting the shaft insertion portion of the male joint along the axial direction on the female joint side, thereby engaging the male joint with the locking member provided on the shaft insertion portion by engaging with the locking groove provided on the shaft portion,
It comprises a gripping portion that is detachably attached between the male and female joints in an engaged state, and a thin cylindrical body integrally provided with the gripping portion,
The gripping portion has a bottom plate portion and an outer wall portion erected along the outer peripheral edge of the bottom plate portion on only one side in the axial direction, the thin cylindrical body is erected on the same side as the outer wall portion relative to the bottom plate portion at the inner peripheral edge of the bottom plate portion, and the tip of the thin cylindrical body is formed in a non-protruding state that is recessed in the axial direction relative to the tip of the outer wall portion.
The thin cylindrical body is a pipe fitting release jig that releases the engagement between the male fitting and the female fitting by moving the gripping portion attached to the pipe fitting in the axial direction toward the female fitting, thereby disengaging the locking member from the locking groove. The locking member is an elastic ring body fitted into the deep inner circumferential groove provided in the shaft insertion portion.
The lock groove is composed of an outer circumferential groove portion provided on the shaft portion and a shallow inner circumferential groove portion provided on the shaft insertion portion.
The aforementioned pipe joint is,
When the male joint and the female joint are engaged, the deep inner groove and the shallow inner groove are adjacent to each other in the axial direction on the female joint side.
The elastic ring body, whose inner diameter in its natural state is smaller than the outer diameter of the shaft portion and whose thickness is smaller than the shallow inner groove portion, is pressed radially between the outer groove portion and the shallow inner groove portion to engage the male joint and the female joint.
The thin cylindrical body is
The pipe joint release tool according to claim 1 or 2 , wherein the elastic ring body is pushed into the deep inner circumferential groove to allow the diameter of the elastic ring body to expand, thereby releasing the engagement between the male joint and the female joint. The thin cylindrical body is provided on the annular gripping portion,
The gripping portion has a rotating shaft that divides the gripping portion and the thin cylindrical body into two in the radial direction.
The gripping portion and the thin cylindrical body are divided into two parts around the rotating shaft and are installed between the engaged male and female joints.
The thin cylindrical body is
The pipe joint detachment jig according to claim 3, wherein the gripping portion attached to the pipe joint moves in the axial direction on the female joint side, thereby entering the gap between the shaft portion and the shaft insertion portion and pushing the elastic ring body from the shallow inner groove portion toward the deep inner groove portion . The pipe joint detachment jig according to claim 1, wherein the expanding force (P) of the elastic ring body is 0.42 kgf or more and 0.46 kgf or less. A pipe joint comprising: a male joint provided with a shaft portion; and a female joint in which a shaft insertion portion is fitted to the shaft portion along the axial direction on the female joint side, thereby a locking member provided on the shaft insertion portion engaging with the male joint by entering a locking groove provided on the shaft portion,
The shaft portion of the male joint is
A gripping portion of a pipe joint detachment jig, separate from the male and female joints, is detachably attached, and the gripping portion is configured to be movable in the axial direction on the female joint side.
The locking member is an elastic ring body,
The expansion force (P) of the elastic ring body, calculated using the strain formula for the arc-shaped spring, is between 0.42 kgf and 0.92 kgf.
In the strain formula for the arc-shaped spring, the wire diameter of the elastic ring body is a value arbitrarily selected from the range of 0.5 mm to 2.0 mm.
The male and female fittings in the engaged state are
A pipe joint wherein the gripping portion attached to the shaft moves axially toward the female joint, thereby creating a gap in which a thin cylindrical body provided on the gripping portion fits between the shaft and the shaft insertion portion, and the locking member is disengaged from the locking groove by the thin cylindrical body, thereby releasing the engagement between the male joint and the female joint. A pipe joint comprising: a male joint provided with a shaft portion; and a female joint in which a shaft insertion portion is fitted to the shaft portion along the axial direction on the female joint side, thereby a locking member provided on the shaft insertion portion engaging with the male joint by entering a locking groove provided on the shaft portion,
In the engaged male and female joints, the axial length of the shaft portion exposed to the outside is greater than the length from the tip of the thin cylindrical body provided on the gripping portion of a pipe joint release jig, which is separate from the male and female joints, to the end located on the opposite side in the axial direction.
The shaft portion of the male joint is
The gripping portion is detachably attached and has a configuration that allows it to move in the axial direction on the female joint side.
The male and female fittings in the engaged state are
A pipe joint in which the gripping portion attached to the shaft moves axially toward the female joint, thereby creating a gap in which the thin cylindrical body fits between the shaft and the shaft insertion portion, and the locking member is disengaged from the locking groove by the thin cylindrical body, thereby releasing the engagement between the male joint and the female joint. The locking member is an elastic ring body fitted into the deep inner circumferential groove provided in the shaft insertion portion.
The lock groove is composed of an outer circumferential groove portion provided on the shaft portion and a shallow inner circumferential groove portion provided on the shaft insertion portion.
The aforementioned pipe joint is,
When the male joint and the female joint are engaged, the deep inner groove and the shallow inner groove are adjacent to each other in the axial direction on the female joint side.
The pipe joint according to claim 6 or 7, wherein the elastic ring body, whose inner diameter in its natural state is smaller than the outer diameter of the shaft portion and whose thickness is smaller than the shallow inner groove portion, is pressed radially between the outer groove portion and the shallow inner groove portion to engage the male joint and the female joint. The pipe fitting according to claim 8, characterized in that the outer circumferential groove is set to a depth of about one- third of the wire diameter of the elastic ring body, and the elastic ring body is set so that its inner diameter in its natural state coincides with the bottom of the outer circumferential groove. The pipe fitting according to claim 6 , wherein the expanding force (P) of the elastic ring body is 0.42 kgf or more and 0.46 kgf or less. A method for separating a pipe joint, comprising a male joint having a shaft portion and a female joint, wherein the shaft insertion portion is fitted to the shaft portion along the axial direction on the female joint side, so that a locking member provided on the shaft insertion portion enters a locking groove provided on the shaft portion and engages with the male joint, the method for separating a male joint and a female joint,
A preparatory step of preparing a pipe joint release jig having a thin cylindrical body provided in the gripping part,
The mounting step involves attaching the gripping portion of the pipe joint release jig to the shaft portion of the male joint which is engaged with the shaft insertion portion of the female joint, in a manner that allows for the attachment of the gripping portion of the pipe joint release jig to be attached to the shaft portion of the male joint which is engaged with the shaft insertion portion of the female joint,
The release step involves moving the gripping portion attached to the shaft portion in the axial direction toward the female joint, thereby causing the thin cylindrical body of the pipe joint release jig to enter the gap between the shaft portion and the shaft insertion portion, and the locking member to be released from the locking groove by the thin cylindrical body, thereby releasing the engagement between the male joint and the female joint.
Equipped with ,
The locking member is an elastic ring body,
The expansion force (P) of the elastic ring body, calculated using the strain formula for the arc-shaped spring, is between 0.42 kgf and 0.92 kgf.
A method for separating a male and female joint , wherein, in the deformation formula for the arc-shaped spring, the wire diameter of the elastic ring body is a value arbitrarily selected from the range of 0.5 mm to 2.0 mm . The method for separating a male and female joint according to claim 11, wherein the expanding force (P) of the elastic ring body is 0.42 kgf or more and 0.46 kgf or less.