JP7819651B2 - Mounting jig and O-ring mounting method - Google Patents

Description

This disclosure relates to an installation jig and an O-ring installation method.

Patent Document 1 discloses an O-ring attachment device for attaching an O-ring to an O-ring groove formed on the inner circumferential surface of a workpiece. In this O-ring attachment device, an O-ring pushing means pushes the O-ring from the outside into the portion between two support points, deforming the O-ring into a shape that fits within the workpiece. The O-ring is then lowered by a robot arm and inserted into the workpiece.

JP 2016-68191 A

However, with the above-mentioned O-ring attachment device, the direction in which the O-ring pushing means pushes the O-ring is different from the direction in which the O-ring attachment device moves to insert the O-ring into the workpiece. As a result, this O-ring attachment device is equipped with multiple means for movement, making it a complex mechanism.

The present disclosure can be realized in the following forms.
According to a first aspect of the present disclosure, there is provided an installation jig for installing an O-ring in an O-ring groove formed in an inner peripheral surface of an object, the installation jig comprising: a guide member having an outer surface and extending along a central axis, the guide member having a first groove formed in the outer surface and extending along the central axis, and a second groove formed in the outer surface along an outer periphery surrounding the central axis for receiving the O-ring; a hook bar having a locking portion capable of locking the O-ring, the hook bar being guided by the first groove and slidable in the direction of the central axis; a stopper attached to the guide member; and a plunger, wherein the locking portion is displaceable between a holding position and an installation position closer to the second groove than the holding position by sliding the hook bar, and the locking portion cooperates with the second groove to hold the O-ring in a deformed state so that the outer diameter of the O-ring is reduced at the holding position, and the O-ring is deformed in the installation position so that the O-ring is deformed in the direction of the central axis by sliding the hook bar. the stopper has a positioning surface parallel to the second groove and a plunger insertion hole through which the plunger is inserted, the distance between the positioning surface and the second groove being set to match the distance between the object end face and the O-ring groove; the guide member has an insertion hole formed on the outer surface that receives the tip of the plunger inserted into the plunger insertion hole; the stopper is attached to the guide member by inserting the plunger into the plunger insertion hole and the insertion hole; and the guide member has a plurality of insertion holes along the direction of the central axis.
According to a second aspect of the present disclosure, there is provided an O-ring mounting method using a mounting jig for mounting an O-ring in an O-ring groove formed in an inner peripheral surface of an object. the mounting jig is a guide member having an outer surface and extending along a central axis, the guide member having a first groove formed on the outer surface and extending along the central axis, and a second groove for receiving the O-ring formed on the outer surface along an outer periphery surrounding the central axis; a hook bar having a locking portion capable of locking the O-ring and guided by the first groove to slide in the direction of the central axis; a stopper attached to the guide member; and a plunger, the locking portion being displaceable between a holding position and an attachment position closer to the second groove than the holding position by the sliding of the hook bar, the object having an object end face parallel to the O-ring groove, the stopper having a positioning surface parallel to the second groove and a plunger insertion hole through which the plunger is inserted, the distance between the positioning surface and the second groove being set to match the distance between the object end face and the O-ring groove, the stopper is attached to the guide member by inserting the plunger into the plunger insertion hole and the insertion hole, and the guide member has a plurality of insertion holes along the direction of the central axis, and the O-ring attachment method includes a holding step of setting the locking portion to the holding position and holding the O-ring in the second groove and the locking portion in a state in which the O-ring is deformed to reduce its outer diameter, an insertion step of inserting the attachment jig holding the O-ring into the inside of the inner surface of the object after the holding step, and an attachment step of setting the locking portion to the attachment position and separating the locking portion from the O-ring to restore the shape of the O-ring and attach the O-ring to the O-ring groove.

(1) According to a first aspect of the present disclosure, there is provided an installation jig for installing an O-ring in an O-ring groove formed in the inner peripheral surface of an object. The installation jig includes a guide member having an outer surface and extending along a central axis, the guide member having a first groove formed in the outer surface and extending along the central axis, and a second groove formed in the outer surface along an outer periphery surrounding the central axis for receiving the O-ring; and a hook bar having a locking portion capable of locking the O-ring, the hook bar being guided by the first groove and slidable in the direction of the central axis. The locking portion is displaceable between a holding position and an installation position closer to the second groove than the holding position by the sliding movement of the hook bar. At the holding position, the locking portion cooperates with the second groove to hold the O-ring in a deformed state so that the outer diameter of the O-ring is reduced. At the installation position, the locking portion moves away from the O-ring, thereby restoring the shape of the O-ring and installing the O-ring in the O-ring groove. According to this embodiment, the O-ring can be changed from a deformed state to a restored state by moving the hook bar in the direction of the central axis, and therefore the O-ring can be attached with a simple configuration of the guide member and the hook bar.
(2) In the mounting jig of the above aspect, the object may have an end face of the object parallel to the O-ring groove, and the mounting jig may further include a stopper attached to the guide member, the stopper having a positioning surface parallel to the second groove, the distance between the positioning surface and the second groove being set to match the distance between the object end face and the O-ring groove. According to this aspect, the second groove and the O-ring groove can be easily aligned by inserting the mounting jig into the object until the positioning surface abuts the object end face.
(3) The mounting jig of the above aspect may further include a plunger, wherein the stopper has a plunger insertion hole through which the plunger is inserted, and the guide member has an insertion hole formed in the outer surface that receives the tip of the plunger inserted into the plunger insertion hole, and the stopper is attached to the guide member by inserting the plunger into the plunger insertion hole and the insertion hole, and the guide member may have a plurality of the insertion holes along the direction of the central axis. According to this aspect, the guide member has a plurality of insertion holes, so that the relative position of the stopper with respect to the guide member can be easily changed by inserting the plunger into a desired one of the plurality of insertion holes. Because the plurality of insertion holes is formed, the relative position of the stopper with respect to the guide member can be adjusted in multiple steps using the plunger to match the distance between the end face of the object and the O-ring groove.
(4) In the mounting jig of the above aspect, the guide member may further have a positioning portion for positioning the locking portion at the mounting position. According to this aspect, the positioning portion makes it possible to easily position the hook bar.
(5) According to a second aspect of the present disclosure, there is provided an O-ring installation method using an installation jig for installing an O-ring in an O-ring groove formed in an inner peripheral surface of an object. The installation jig includes a guide member having an outer surface and extending along a central axis, the guide member having a first groove formed on the outer surface and extending along the central axis, and a second groove formed on the outer surface along an outer periphery surrounding the central axis for receiving the O-ring, and a hook bar having a locking portion capable of locking the O-ring, the hook bar being guided by the first groove and slidable in the direction of the central axis. The locking portion is displaceable between a holding position and an installation position closer to the second groove than the holding position by sliding the hook bar. The O-ring installation method includes a holding step of setting the locking portion to the holding position and holding the O-ring in the second groove and the locking portion while deforming the O-ring so that its outer diameter is reduced; an insertion step of inserting the installation jig holding the O-ring into the inner circumferential surface of the object after the holding step; and an installation step of setting the locking portion to the installation position and separating the locking portion from the O-ring to restore the shape of the O-ring and install the O-ring in the O-ring groove after the insertion step. According to this embodiment, the O-ring can be installed by performing the holding step, the insertion step, and the installation step. In the installation step, the locking portion can be moved to the installation position by moving the hook bar, thereby changing the O-ring from its deformed state to its restored state. Therefore, the O-ring can be installed using an installation jig with a simple configuration consisting of a guide member and a hook bar.
The present disclosure may be realized in various forms other than the mounting jig and the O-ring mounting method, for example, in the form of a manufacturing method of a mounting jig.

FIG. 3A and 3B are front and rear views of a guide member; 1A and 1B are front and side views of a hook bar. 3A and 3B are a rear view and a plan view of the stopper main body. 10 is a flowchart showing an O-ring installation procedure. FIG. 10 is an explanatory diagram illustrating a method for attaching an O-ring.

A. Embodiments:
A1. Structure of the mounting jig:
FIG. 1 is a perspective view of the mounting jig 1. The mounting jig 1 has a guide member 10, a hook bar 20, a stopper 30, and a pressing member 40. FIG. 2 is a front view and a rear view of the guide member 10. FIG. 3 is a front view and a side view of the hook bar 20. FIG. 4 is a front view and a plan view of the stopper main body 31. FIG. 5 is a flowchart showing an O-ring mounting procedure for mounting an O-ring R using the mounting jig 1. FIG. 6 is an explanatory diagram illustrating the O-ring mounting method.

The mounting jig 1 is a jig for mounting an O-ring R into an O-ring groove WG formed on the inner surface WS of a cylindrical object W shown in Figure 6. The object W has an object end face WF that is parallel to the O-ring groove WG.

In this embodiment, the inner diameter of the object W is approximately 40 mm. The vertical length of the object W is approximately 200 mm. The O-ring groove WG is formed around the entire circumference of the inner surface WS. Multiple O-ring grooves WG are formed. The multiple O-ring grooves WG are formed at equal intervals in the direction of the central axis CX. The pitch of the multiple O-ring grooves WG is approximately 14 mm. The thickness of the O-ring R is approximately 4 mm. However, the dimensions of the object W for which the mounting jig 1 is used are not limited to these.

As shown in FIG. 1, the guide member 10 has a cylindrical shape extending generally along the central axis CX. FIG. 1 also shows the up-down direction and the front-to-rear direction, which is perpendicular to the up-down direction. The up-down direction is the direction along the central axis CX of the guide member 10. The front-to-rear direction is the direction along the diameter of the guide member 10. The surface of the guide member 10 on which the first groove 12 (described below) is formed is the front of the mounting jig 1. The direction from the back surface facing the front toward the front is the forward direction. The directions shown in FIGS. 2 and 6 are the same as those shown in FIG. 1. The direction shown in FIG. 3 is the direction when the hook bar 20 is attached to the guide member 10. Similarly, the direction shown in FIG. 4 is the direction when the stopper 30 is attached to the guide member 10.

The mounting jig 1 is typically held by a worker so that the up-down direction is roughly aligned vertically. The guide member 10 is made of resin, which allows the mounting jig 1 to be lightweight.

The guide member 10 extends along the central axis CX. The guide member 10 has an outer surface 11 exposed to the outside. The guide member 10 has a first groove 12, a second groove 13, a third groove 14 (Figure 2), multiple pairs of insertion holes 15, and a positioning portion 16 formed on the outer surface 11. The first groove 12 extends along the central axis CX. As shown in Figure 2, the first groove 12 is formed on the front surface of the guide member 10. The upper end of the first groove 12 extends to the upper end of the guide member 10. In contrast, the lower end of the first groove 12 does not extend to the lower end of the guide member 10 and is closed. The positioning portion 16 is formed at the lower end of the first groove 12. Specifically, the positioning portion 16 is a step formed in the vertical direction between the outer surface 11 and the bottom surface forming the first groove 12, which is approximately parallel to the outer surface 11. The positioning portion 16 allows the positioning of the hook bar 20, as will be described in detail later. The downward first groove tip 12a of the first groove 12 extends further downward than the second groove 13.

The second groove 13 is a groove for receiving the O-ring R. The second groove 13 is formed along the outer periphery surrounding the central axis CX. Specifically, the second groove 13 is formed along a circle extending in the diameter direction and centered on the central axis CX. The first groove 12 and the second groove 13 are connected. At the connection between the first groove 12 and the second groove 13, a first groove slope 12b is formed, connecting the side surface that forms the first groove 12 and extends in the approximately diameter direction with the side surface that forms the second groove 13 and extends in the approximately diameter direction. The first groove slope 12b is inclined with respect to the central axis CX when the guide member 10 is viewed from the front. This reduces the load on the O-ring R while it is held, as will be described in detail later.

The third groove 14, shown in the rear view of Figure 2, is formed on the rear surface of the guide member 10. A guide pin 51, shown in Figure 4, is inserted into the third groove 14. The third groove 14 is formed in a position facing the first groove 12 across the central axis CX. Both ends of the third groove 14 in the vertical direction are closed and do not extend to the vertical ends of the guide member 10. The third groove 14 is formed generally in the vertical range RE in which the insertion hole 15 is formed.

The multiple pairs of insertion holes 15 are holes into which plungers 32 (Figure 1) are inserted. More specifically, the pair of insertion holes 15 receives the tip of the plunger 32 inserted into the plunger insertion hole 36 (Figure 4) described below. Each pair of insertion holes 15 faces each other across the central axis CX. The pair of insertion holes 15 is arranged along the diameter direction of the guide member 10. The multiple pairs of insertion holes 15 are arranged at equal intervals in the vertical direction. The vertical spacing between the multiple pairs of insertion holes 15 is the same as the spacing between the O-ring grooves WG of the object W.

The hook bar 20 shown in Figure 3 is made of aluminum. The hook bar 20 has a bar main body 22, a bar connecting portion 24, and a locking portion 26. The bar main body 22 is elongated in the vertical direction. The width of the bar main body 22 is slightly narrower than the width of the first groove 12 of the guide member 10. This allows the bar main body 22 to fit into the first groove 12. The hook bar 20 is guided by the first groove 12 and can slide in the direction of the central axis CX. Furthermore, because the width of the bar main body 22 is slightly narrower than the width of the first groove 12 of the guide member 10, when the hook bar 20 is fitted into the first groove 12, it is possible to reduce fluctuations in the relative position of the hook bar 20 with respect to the guide member 10 in the circumferential direction. A curved surface 22a is formed on the front of the bar main body 22. The curved surface 22a is the surface exposed to the outside when the hook bar 20 is fitted into the first groove 12. The curved surface 22a prevents interference between the mounting jig 1 and the inner surface WS when the mounting jig 1 is inserted into the object W.

The bar connecting portion 24 connects the bar main body portion 22 and the locking portion 26. As shown in the front view of Figure 3, the width of the bar connecting portion 24 when viewed from the front is narrower than the width of the bar main body portion 22. Also, as shown in the side view of Figure 3, the thickness of the bar connecting portion 24 when viewed from the side is thinner than the thickness of the bar main body portion 22.

The locking portion 26 is capable of locking an O-ring R. The locking portion 26 is located at the downward tip of the hooking bar 20. As shown in the front view of Figure 3, the width of the locking portion 26 when viewed from the front is the same as that of the bar connecting portion 24. As shown in the side view of Figure 3, the thickness of the locking portion 26 when viewed from the side is the same as that of the bar main body 22. Like the bar main body 22, a curved surface 26a is formed on the front of the locking portion 26. The curved surface 26a is the surface that is exposed to the outside when the hooking bar 20 is fitted into the first groove 12.

As described above, the bar main body 22 and the locking portion 26, which have the same thickness, are connected by the bar connecting portion 24, which is thinner than either the bar main body 22 or the locking portion 26. As a result, a bar groove 28 is formed between the bar main body 22 and the locking portion 26, recessed further back than both the curved surface 22a and the curved surface 26a, i.e., recessed rearward.

As shown in FIG. 1, the stopper 30 has a stopper main body 31, a pair of plungers 32, and a positioning surface 33. As shown in FIG. 4, the stopper main body 31 has an annular shape. The stopper main body 31 has a guide member insertion hole 34, a pair of plunger insertion holes 36, and a guide pin insertion hole 37. As shown in FIG. 6, the guide member 10 is inserted into the guide member insertion hole 34. A plunger 32 is inserted into each of the pair of plunger insertion holes 36. The pair of plunger insertion holes 36 face each other across the central axis CX. The pair of plunger insertion holes 36 are arranged along the diameter direction of the guide member 10. As shown in FIG. 4, a guide pin 51 is inserted into the guide pin insertion hole 37. As shown in FIG. 6, the positioning surface 33 is parallel to the second groove 13.

As shown in FIG. 1, the pressing member 40 has a circular ring shape. The pressing member 40 is made of resin. The pressing member 40 is fixed to the upper end of the guide member 10 by a fastening member (not shown).

As shown in Figure 1, the hook bar 20 is fitted into the first groove 12 of the guide member 10. Then, a stopper 30 and a retaining member 40 are attached to the periphery of the guide member 10 with the hook bar 20 fitted into it.

When the stopper 30 is attached, the guide pin 51 shown in FIG. 4 is fixed in the guide pin insertion hole 37 of the stopper 30, with the guide pin insertion hole 37 of the stopper 30 shown in the plan view of FIG. 4 and the third groove 14 of the guide member 10 shown in the rear view of FIG. 2 overlapping in the diametric direction of the guide member 10. More specifically, the guide pin 51 is fixed in a state where its tip closest to the central axis CX protrudes from the guide pin insertion hole 37 and is inserted into the third groove 14 of the guide member 10. As a result, with the guide pin 51 fitted in the third groove 14, the stopper 30 moves vertically relative to the guide member 10. By fitting the guide pin 51 in the third groove 14, the stopper 30 can move vertically while its position in the circumferential direction of the guide member 10 is fixed.

The vertical position of the stopper 30 relative to the guide member 10 is fixed by the plunger 32. As shown in FIG. 6, the plunger 32 has a plunger body 32a and a plunger tip 32b. The plunger body 32a of the plunger 32 is fixed to the stopper 30. The plunger 32 is configured to be changeable between a protruding state in which the plunger tip 32b protrudes from the plunger body 32a in the protruding direction as shown in FIG. 6, and a non-protruding state in which the plunger tip 32b is built into the plunger body 32a, as shown in FIG. 6. The plunger tip 32b is biased in the protruding direction by a spring built into the plunger body 32a. As shown in FIG. 6, the plunger tip 32b of the plunger 32 in the protruding state is inserted into the insertion hole 15 of the guide member 10, thereby fixing the stopper 30 to the guide member 10.

To change the vertical position of the stopper 30 relative to the guide member 10, the plunger 32 is first changed from a protruding state to a non-protruding state. The position of the stopper 30 is then changed so that the plunger insertion hole 36 in the stopper 30 and the insertion hole 15 in the guide member 10 are misaligned in the vertical direction. Specifically, the stopper 30 is moved up or down relative to the guide member 10. The plunger 32 is then changed from a non-protruding state to a protruding state. Even after being changed to the protruding state, the plunger insertion hole 36 and the insertion hole 15 are still misaligned in the vertical direction, so the plunger tip 32b is in contact with the outer surface 11 of the guide member 10 due to the built-in spring. In this state, the stopper 30 is moved up or down relative to the guide member 10 until the plunger insertion hole 36 and the insertion hole 15 are aligned in the vertical direction. When the plunger insertion hole 36 and the insertion hole 15 are aligned in the vertical direction, the spring force causes the plunger tip 32b to enter the insertion hole 15. This fixes the stopper 30 to the guide member 10.

The hook bar 20 is guided by the first groove 12 and slides in the direction of the central axis CX. The hook bar 20 is held down by the stopper 30 and the holding member 40, allowing it to slide along the central axis CX while maintaining a position approximately parallel to the central axis CX.

A2. Overview of O-ring installation method:
An overview of the procedure for attaching the O-ring R will be described using FIG. 6 . The hook bar 20 moves, i.e., slides, relative to the guide member 10, allowing the locking portion 26 to be displaced between a holding position PO1 and an attachment position PO2. The holding position PO1 and the attachment position PO2 are defined by the tip of the locking portion 26 in the vertical direction, i.e., the position of the lower end. The attachment position PO2 is the tip position of the locking portion 26 when the locking portion 26 abuts against the positioning portion 16. The attachment position PO2 is closer to the second groove 13 than the holding position PO1. Specifically, the distance between the locking portion 26 and the second groove 13 in the direction of the central axis CX at the attachment position PO2 is shorter than the distance between the locking portion 26 and the second groove 13 in the direction of the central axis CX at the holding position PO1.

At the holding position PO1, the locking portion 26 cooperates with the second groove 13 to hold the O-ring R in a state in which it has been deformed to reduce its outer diameter. Specifically, the worker attaches the O-ring R to the mounting jig 1 by fitting the O-ring R into the second groove 13 and the bar groove 28. The portion of the O-ring R hooked onto the bar groove 28 is pulled upward relative to the other portions, resulting in a deformed state in which its outer diameter is reduced. Furthermore, as part of the O-ring R is pulled upward by the locking portion 26, tension is applied to the O-ring R sufficient to prevent it from coming off the mounting jig 1. The outer diameter D2 of the O-ring R in this state is smaller than the diameter D1 of the O-ring R when no external force is applied.

When the locking portion 26 moves from the holding position PO1 to the mounting position PO2, the O-ring R separates from the locking portion 26 and deforms to return to its original shape, restoring the shape of the O-ring R. Then, by restoring the O-ring R to the position of the O-ring groove WG, the O-ring R is attached to the O-ring groove WG.

A3. Details of O-ring installation method:
5 and 6, the procedure for installing the O-ring R will be described in detail. In this embodiment, the O-ring R is installed in the lowest O-ring groove WG among the multiple O-ring grooves WG.

In step S10 of Figure 5, the stopper 30 is aligned at the desired position. Specifically, after the plunger 32 is set to the non-protruding state as described above, the stopper 30 is moved vertically relative to the guide member 10, and the tip of the plunger 32 is fitted into the insertion hole 15 at the desired position, thereby fixing the stopper 30 in place. In this embodiment, the O-ring R is attached to the lowest O-ring groove WG, so the stopper 30 is attached to the topmost insertion hole 15 of the guide member 10.

In step S20, the locking portion 26 of the hook bar 20 is set to the holding position PO1, and the O-ring R is attached to the attachment jig 1. Specifically, the O-ring R is held in the second groove 13 and the locking portion 26 while being deformed to reduce its outer diameter. Here, the guide member 10 is formed with a first groove slope 12b (Figure 2). Therefore, compared to when a corner is formed by the first groove 12 and the second groove 13, it is possible to prevent external forces from being concentrated on the O-ring R, thereby reducing the load on the O-ring R.

In step S30 of Figure 5, the mounting jig 1 with the O-ring R attached is inserted inside the inner surface WS of the object W. In step S30, as shown in Figure 6, the positioning surface 33 of the stopper 30 is placed in contact with the object end surface WF of the object W. The insertion hole 15 of the guide member 10 is set so that the distance D3 between the positioning surface 33 and the second groove 13 matches the distance D3 between the object end surface WF and the O-ring groove WG. By placing the positioning surface 33 of the stopper 30 in contact with the object end surface WF of the object W in step S30, the second groove 13 can be aligned with the O-ring groove WG.

In step S40 of Figure 5, the hook bar 20 is set to the mounting position PO2, and the O-ring R is attached to the object W. Specifically, the locking portion 26 moves away from the O-ring R, restoring the shape of the O-ring R so that the O-ring R fits into the O-ring groove WG. When the downward tip of the hook bar 20 abuts the positioning portion 16, the locking portion 26 is positioned at the mounting position PO2. Therefore, the worker can easily set the locking portion 26 to the mounting position PO2 by lowering the hook bar 20 until the downward tip abuts the positioning portion 16. In step S50 of Figure 5, the attachment jig 1 is removed from the object W, completing the attachment of the O-ring R.

If the O-ring R is to be attached to a different O-ring groove WG, the position of the stopper 30 is changed in step S10, and steps S20 to S50 are performed.

Step S20 is also referred to as the holding step, step S30 is also referred to as the insertion step, and step S40 is also referred to as the attachment step.

In the embodiment described above, the mounting jig 1 includes a guide member 10 and a hook bar 20. At the holding position PO1, the locking portion 26 of the hook bar 20 cooperates with the second groove 13 of the guide member 10 to hold the O-ring R in a deformed state that reduces its outer diameter. At the mounting position PO2, the locking portion 26 moves away from the O-ring R, restoring the shape of the O-ring R and mounting the O-ring R in the O-ring groove WG. Therefore, the O-ring R can be mounted with the simple configuration of the guide member 10 and the hook bar 20. Using the mounting jig 1, the O-ring R can be mounted in a shorter time than if it were mounted manually. The mounting jig 1 is particularly suitable for mounting an O-ring R on an object W with a small diameter inner circumferential surface WS that is difficult to insert a hand into.

The stopper 30 also has a positioning surface 33, and the distance D3 between the positioning surface 33 and the second groove 13 is set to match the distance D3 between the object end face WF and the O-ring groove WG. This makes it easy to align the second groove 13 with the O-ring groove WG by inserting the mounting jig 1 into the object W in step S30 until the positioning surface 33 abuts the object end face WF.

The stopper 30 is attached to the guide member 10 by inserting the plunger 32 into the plunger insertion hole 36 and the insertion hole 15. The guide member 10 has multiple insertion holes 15 along the direction of the central axis CX. This makes it easy to change the relative position of the stopper 30 with respect to the guide member 10. Because multiple insertion holes 15 are formed, the relative position of the stopper 30 with respect to the guide member 10 can be adjusted in multiple stages using a plunger to match the distance between the object end face WF and the O-ring groove WG. The guide member 10 also has a positioning portion 16 for positioning the locking portion 26 at the mounting position PO2. The positioning portion 16 therefore makes it easy to position the hook bar 20.

B. Other Embodiments:
In the above embodiment, the mounting position PO2 is located above the holding position PO1. In another embodiment, the mounting position PO2 may be located below the holding position PO1. Also, in the above embodiment, the positioning portion 16 is a step formed by the bottom surface of the first groove 12 and the outer surface 11. The positioning portion 16 is not limited to this and may be configured to limit the movement of the hook bar 20. For example, a protrusion that protrudes toward the central axis CX may be provided at the upper end of the hook bar 20, and a positioning portion that abuts against the protrusion may be provided on the guide member 10. Also, the mounting jig 1 may have a configuration for positioning the locking portion 26 at the holding position PO1, similar to the mounting position PO2.

This disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be replaced or combined as appropriate to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

1...mounting jig, 10...guide member, 11...outer surface, 12...first groove, 12a...first groove tip, 12b...first groove inclined surface, 13...second groove, 14...third groove, 15...insertion hole, 16...positioning portion, 20...hook bar, 22...bar main body, 22a, 26a...curved surface, 24...bar connecting portion, 26...engaging portion, 28...bar groove, 30...stopper, 31...stopper main body, 32...plunger, 32a...plunger Plunger body, 32b... plunger tip, 33... positioning surface, 34... guide member insertion hole, 36... plunger insertion hole, 37... guide pin insertion hole, 40... retainer, 51... guide pin, CX... center axis, D1, D2... outer diameter, D3... distance, PO1... holding position, PO2... mounting position, R... O-ring, RE... range, W... object, WF... object end face, WG... O-ring groove, WS... inner surface

Claims (3)

An attachment jig for attaching an O-ring to an O-ring groove formed on the inner circumferential surface of an object,
a guide member having an outer surface and extending along a central axis, the guide member having a first groove formed on the outer surface and extending along the central axis, and a second groove for receiving the O-ring formed on the outer surface along an outer periphery surrounding the central axis;
a hook bar having a locking portion capable of locking the O-ring, the hook bar being guided by the first groove and slidable in the direction of the central axis;
a stopper attached to the guide member;
a plunger ;
the engaging portion is displaceable between a holding position and an attachment position that is closer to the second groove than the holding position by sliding of the hook bar,
The locking portion is
At the holding position, the O-ring is held in a state in which the outer diameter of the O-ring is reduced in cooperation with the second groove,
At the mounting position, the O-ring is separated from the O-ring, thereby restoring the shape of the O-ring and mounting the O-ring in the O-ring groove ;
the object has an object end surface parallel to the O-ring groove;
the stopper has a positioning surface parallel to the second groove and a plunger insertion hole through which the plunger is inserted,
a distance between the positioning surface and the second groove is set to match a distance between an end surface of the object and the O-ring groove;
the guide member has an insertion hole formed on the outer surface, the insertion hole receiving the tip of the plunger inserted into the plunger insertion hole;
the stopper is attached to the guide member by inserting the plunger into the plunger insertion hole and the insertion hole;
The guide member has a plurality of insertion holes along the direction of the central axis . The mounting jig according to claim 1,
The guide member further includes a positioning portion for positioning the locking portion at the mounting position. 1. An O-ring mounting method using a mounting jig for mounting an O-ring in an O-ring groove formed on an inner circumferential surface of an object, comprising:
The mounting jig is
a guide member having an outer surface and extending along a central axis, the guide member having a first groove formed on the outer surface and extending along the central axis, and a second groove for receiving the O-ring formed on the outer surface along an outer periphery surrounding the central axis;
a hook bar having a locking portion capable of locking the O-ring, the hook bar being guided by the first groove and slidable in the direction of the central axis;
a stopper attached to the guide member;
a plunger ;
the engaging portion is displaceable between a holding position and an attachment position that is closer to the second groove than the holding position by sliding of the hook bar,
the object has an object end surface parallel to the O-ring groove;
the stopper has a positioning surface parallel to the second groove and a plunger insertion hole through which the plunger is inserted,
a distance between the positioning surface and the second groove is set to match a distance between an end surface of the object and the O-ring groove;
the guide member has an insertion hole formed on the outer surface, the insertion hole receiving the tip of the plunger inserted into the plunger insertion hole;
the stopper is attached to the guide member by inserting the plunger into the plunger insertion hole and the insertion hole;
The guide member has a plurality of insertion holes along the direction of the central axis,
The O-ring mounting method includes:
a holding step of setting the locking portion at the holding position and holding the O-ring in the second groove and the locking portion in a state in which the O-ring is deformed so that the outer diameter of the O-ring is reduced;
an insertion step of inserting the mounting jig holding the O-ring into the inside of the inner circumferential surface of the object after the holding step;
and an installation step of, after the insertion step, setting the locking portion to the installation position and moving the locking portion away from the O-ring to restore the shape of the O-ring and install the O-ring in the O-ring groove.