Elastic ring assembly device

Abstract

To provide an elastic ring assembly device that expands a diameter of an elastic ring and can automatically assemble the same to a designated position of a work-piece head.SOLUTION: An elastic ring assembly device comprises a reception jig 8 which fixes a work-piece 5 and can integrally rotate the work-piece. When a chuck claw 30 releases gripping of a mask spring 1, the mask spring 1 is guided by an outer wall of a guide pin 20 and is dropped by gravity to a holding claw 21. When the holding claw 21 capable of gripping and lifting the guide pin 20 is operated to be opened, the mask spring 1 guided by the outer wall of the guide pin 20 freely falls down to and contacts a tip spherical part 9 of the work-piece 5. When a cylindrical assembly member 22 which slides on an inner wall of a centering member 23 descends to press the mask spring 1 in an axis line direction, the mask spring 1 is temporarily fixed to an upper end of the work-piece 5 while expanding an inner diameter of the mask spring 1. By this, the mask spring 1 is regulated in a horizontal attitude by the guide pin 20, and both of ensuring centering of the mask spring 1 and extrusion press-fitting of the same into the work-piece 5 are achieved by the assembly member 22.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an elastic ring assembling apparatus and an assembling method for assembling an elastic ring onto a columnar workpiece. [Background Art]

[0002] In a manufacturing process of a gas sensor element used for combustion control or the like of an internal combustion engine, there is a step of thermally spraying an insulating layer on a non-detection electrode portion of a workpiece while protecting the detection electrode portion of the element (workpiece) with a mask spring as an auxiliary material. In a pre-process for forming an insulating layer on the non-detection electrode portion of the gas sensor element by thermal spraying, a mask spring (elastic ring) as an auxiliary material is assembled to the detection electrode portion of the element (workpiece) to protect the detection electrode portion from being sprayed with the insulating layer.

[0003] As an apparatus for assembling an elastic ring onto a columnar workpiece, for example, the elastic ring assembling apparatus and assembling method described in Patent Document 1 are known. The disclosure of Patent Document 1 includes a guide member having a tip shape that can be substantially continuous with an outer contour of a ring mounting groove forming portion of a pin (equivalent to a workpiece) onto which the elastic ring is assembled, and a finger that can reciprocate while rotating along the guide member or the pin. The elastic ring fitted to the guide member is pushed by the rotating finger in a state where the guide member is continuous with the pin, moves from the guide member to the pin, and is assembled into the ring mounting groove while its inner diameter is expanded along the pin. [Prior Art Literature] [Patent Literature]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2006-88275 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, Patent Document 1 does not disclose a configuration in which the fingers are moved axially to press the elastic ring against the pin (equivalent to a workpiece), and the axis of the fingers is aligned with the axis of the pin (equivalent to a workpiece) when pressing the elastic ring against the pin. While this document 1 discloses a configuration in which the finger contacts the elastic ring at multiple points in the circumferential direction, it does not disclose a configuration in which the finger contacts the elastic ring at its end face in the circumferential direction.

[0006] The present invention has been made in view of the above, and its object is to provide an elastic ring assembly device and an elastic ring assembly method that can automatically assemble an elastic ring to a specified position on the head of a workpiece by expanding its diameter. [Means for solving the problem]

[0007] The present invention relates to an elastic ring assembly device for temporarily fixing an elastic ring (1) to the tip of a columnar workpiece (5), A receiving jig (8) that temporarily fixes one end of the workpiece and allows the workpiece to rotate as a whole, A chuck jaw (30) capable of gripping an elastic ring for temporary fixing to the other end of the workpiece is positioned above the workpiece. A guide pin (20) that guides the elastic ring along its outer wall when the chuck jaws are released, allowing it to fall by gravity, The aforementioned guide pin is gripped and raised / lowered by a retaining claw (21), A cylindrical assembly member (17) that can press an elastic ring guided to the upper end of a workpiece in the axial direction, and temporarily fixes the elastic ring to the upper end of the workpiece while expanding the inner diameter of the elastic ring when pressed, A centering member (23) is slidable in the axial direction within the assembly member, capable of centering the workpiece and the guide pin, and has an air passage (28) inside, The system employs a configuration that includes a suction means (14) capable of sucking the guide pin through the air passage.

[0008] The present invention relates to an elastic ring assembly method for temporarily fixing an annular elastic ring with a variable inner diameter to the tip of a columnar workpiece, A process of rotating the workpiece (5), which is positioned on the receiving jig (8), around its axis, A step of attaching a centered guide pin (20) to the tip of the workpiece, A step of guiding the elastic ring (1) that is falling by gravity along the guide pin to the tip of the workpiece using the guide pin, The process involves the assembly member (22) pressing the elastic ring against the tip of the workpiece during workpiece rotation, thereby increasing the inner diameter of the elastic ring and temporarily fixing the elastic ring to the tip of the workpiece, The process includes the step of temporarily fixing the elastic ring to the tip of the workpiece and then releasing the pressure on the elastic ring by the assembly member.

[0009] According to the elastic ring assembly device of the present invention, the elastic ring of the auxiliary material is centered with the element using a guide pin, and while maintaining a horizontal position with the assembly member, the elastic ring is pressed against the spherical leg at the tip of the workpiece, thereby reducing frictional resistance with the workpiece while expanding the inner diameter of the elastic ring, and the elastic ring can be moved to a predetermined position on the workpiece.

[0010] According to the elastic ring assembly device and elastic ring assembly method of the present invention, a guide pin restricts the elastic ring to a horizontal position, and the assembly member ensures both centering of the elastic ring and press-fitting it into the workpiece. [Brief explanation of the drawing]

[0011] [Figure 1] A front view showing an elastic ring assembly device according to an embodiment of the present invention. [Figure 2] A partial cross-sectional view showing the suction operation of the guide pin in this embodiment. [Figure 3] A partial cross-sectional view showing the operation process of the assembly device of this embodiment. [Figure 4] A partial cross-sectional view showing the operation process of the assembly device of this embodiment. [Figure 5] A partial cross-sectional view showing the alignment process of the assembly device of this embodiment. [Figure 6] A partial cross-sectional view showing the operation process of the assembly device of this embodiment. [Figure 7]A partial cross-sectional view showing an operation process of the assembling apparatus of the present embodiment, [Figure 8] A perspective view showing the elastic ring used in the present embodiment, [Figure 9] A partial cross-sectional front view showing the operation of the assembling apparatus of the present embodiment, [Figure 10] A partial cross-sectional view showing a temporary fixing process of the workpiece and the elastic ring in the present embodiment, [Figure 11] A partial cross-sectional view showing a temporary fixing process of the workpiece and the elastic ring in the comparative embodiment, [Figure 12] A partial cross-sectional view showing a temporary fixing process of the workpiece and the elastic ring in the comparative embodiment, [Figure 13] A partial cross-sectional view showing a temporary fixing process of the workpiece and the elastic ring in the comparative embodiment, [Figure 14] A partial cross-sectional view showing a temporary fixing process of the workpiece and the elastic ring in the comparative embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an elastic ring assembling apparatus and an elastic ring assembling method according to a plurality of embodiments will be described with reference to the drawings. In the plurality of embodiments, substantially identical components are denoted by the same reference signs, and descriptions thereof will be omitted.

[0013] (First Embodiment) A first embodiment of the present invention will be described with reference to FIGS. 1 to 10.

[0014] The elastic ring assembling apparatus according to the first embodiment of the present invention is an apparatus for temporarily assembling a mask spring corresponding to an elastic ring to an electrode portion of an element such as a gas sensor. Herein, the element is referred to as a workpiece. As shown in FIG. 9, the mask spring (1) assembled to the leg portion (6) of the workpiece (5) is formed of an annular elastic member with a variable inner diameter, and is temporarily fixed to the distal outer peripheral wall (9) of the leg portion (6) of the workpiece (5).

[0015] The mask spring 1, which corresponds to an elastic ring, consists of an elastic member wound in a ring shape. As shown in Figure 8, it consists of a cylindrical portion 2 wound around the circumference one or more times, and expanding portions 3 and 4 that expand in a conical shape from both axial ends of the cylindrical portion 2 in a direction away from the axis, and are closed in the circumferential direction. The wound mask spring 1 is elastically deformable, and the inner diameter of the ring is variable in the expanding direction shown by the arrow in Figure 8. For example, if internal pressure is applied to the mask spring 1, the inner diameter will increase.

[0016] When assembling the mask spring 1 to the workpiece 5 corresponding to the element, as shown in Figure 9, the workpiece 5 is supported by the center pin 7 and temporarily fixed to the receiving jig 8. Then, the mask spring 1 is temporarily fixed (temporarily assembled) to the spherical tip portion 9 of the leg portion 6 by the elastic ring assembly device of this embodiment.

[0017] The support fixture 8, which can switch between temporarily fixing and releasing the workpiece 5, is rotatable integrally with the workpiece 5, which is supported by the center pin 7. As shown in Figures 3A and 3B, the mask spring 1 can be set on the retaining claw 21 with its inner diameter restricted by the outer circumferential wall surface of the guide pin 20, and when the retaining claw 21 is opened, it can be set horizontally on the spherical tip portion 9 of the workpiece 5.

[0018] When the mask spring 1 is assembled to the spherical tip portion 9 of the workpiece 5, as shown in Figure 10, the rotation direction of the workpiece 5 is rotated in the opposite direction to the spring winding direction. As a result, when the end face 221 of the assembly member 22 shown in Figure 4D pushes the expanding portion 4 downward in the direction of arrow 39, the expanding portion 3 deforms in a direction that loosens the spring winding force in contact with the spherical tip portion 9, that is, in a direction that expands the inner diameter of the mask spring 1, thereby reducing the pressing force by the assembly member 22.

[0019] Next, the elastic ring assembly device of this embodiment will be described with reference to Figures 1 to 7. A servo slider 12, fixed to a bracket 11 of the main body 10, moves the bracket 13 up and down in the direction of arrow 27. A suction means 14 attached to the bracket 13 moves the assembly member 17 up and down via a spring 16 of the assembly unit 36. On the other hand, the upper and lower units 34 of the main body of the device 10 are devices that guide the mask spring 1 while centering it by passing a guide pin 20 through the spherical tip 9 of the leg portion 6 of the workpiece 5, which is temporarily fixed to the receiving jig 8 via the center pin 7 shown in Figure 9.

[0020] The elastic ring assembly device operates in the order shown in Figures 3A, B, C, 4D, E, and F. Its configuration will now be explained. The chuck jaws 30 constituting the upper and lower unit 34 are capable of gripping the mask spring 1 above the workpiece 5 and are movable up and down. The chuck jaws 30 can insert the mask spring 1 from the upper end of the guide pin 20 and release the grip on the mask spring 1 after insertion.

[0021] The retaining claws 21 that make up the upper and lower unit 34 can support the mask spring 1 on their upper end surface and move up and down. When the retaining claws 21 are opened, the mask spring 1 is allowed to fall freely along the guide pin 20. The pair of retaining claws 21 are capable of gripping the outer circumferential surface of the guide pin 20, and when the recess 26 of the guide pin 20 engages with the spherical tip portion 9 of the workpiece 5 and grips the outer circumferential surface of the guide pin 20, centering is achieved.

[0022] As shown in Figure 2, the centering member 23 constituting the assembly unit 36 ​​has a tapered surface 24 that is recessed in a frustoconical shape at its lower end. The frustoconical portion 25 at the upper end of the guide pin 20 can engage with this tapered surface 24. The centering member 23 and the spherical tip portion 9 of the workpiece 5 hold the guide pin 20 in a vertical position.

[0023] The centering member 23 has a basic cylindrical shape and a conical tapered inner wall surface 24 at its lower end that guides the frustoconical portion 25 of the tip of the guide pin 20. The centering member 23 has an air passage 28 through which air from the suction device passes in the axial direction.

[0024] As shown in Figure 2, the assembly member 22 constituting the assembly unit 36 ​​has a cylindrical shape and is movable directly above the workpiece 5. The inner wall of this assembly member 22 is axially slidable with respect to the outer wall of the centering member 23. As a result, when the lower end of the assembly member 22 presses against the mask spring 1 during the downward movement of the assembly member 22, centering in the pressing direction is ensured.

[0025] The assembly member 22 is cylindrical in shape, and the internal centering member 23 and guide pin 20 can be inserted through it. When the assembly member 22 is lowered, the circumferential annular surface contact between the lower end face 221 of the assembly member 22 and the mask spring 1 presses the mask spring 1 against the tip spherical portion 9 of the workpiece 5, causing the mask spring 1 to expand in diameter and temporarily assemble to the leg portion 6 of the workpiece 5.

[0026] The guide pin 20, which constitutes the upper and lower unit 34, has a cylindrical shape, with a frustoconical portion 25 at its upper end and a frustoconical recess 26 at its lower end that engages circumferentially with the spherical tip portion 9 of the workpiece 5. The outer surface of the guide pin 20 allows the mask spring 1 to be inserted axially. Furthermore, the guide pin 20 can be gripped by a pair of retaining claws 21.

[0027] The guide pin 20 is held in a vertical position by being gripped by the retaining claw 21 or by being centered by the centering member 23 and the workpiece 5.

[0028] The upper and lower unit 34 consists of a chuck jaw 30, a retaining jaw 21, and a guide pin 20. The assembly unit 36 ​​consists of a centering member 23 and an assembly member 22. The suction means 14 is a device that sucks air from the air passage 28 of the centering member 23, attracts the frustoconical portion 25 of the guide pin 20 to the tapered inner wall surface 24 of the centering member 23, and pulls up the guide pin 20.

[0029] Furthermore, the mask spring 1 has its inner diameter restricted by the outer diameter of the guide pin 20 and is set on the retaining claw 21, so that when the retaining claw 21 is opened, the mask spring 1 can be set horizontally on the spherical tip 9 of the workpiece 5. Furthermore, by lowering the assembly member 22, the mask spring 1 is pressed against the workpiece 5 (equivalent to an element), and the mask spring 1 expands in diameter while being transferred to the element.

[0030] The mask spring 1 actually has variations in its winding force. To temporarily assemble the mask spring 1, the pressing force of the assembly member 22 is set to overcome the winding force of the mask spring 1, and the mask spring 1 is temporarily assembled by pressing it with the assembly member 22 and expanding its diameter.

[0031] Next, regarding the operation of the elastic ring assembly device of the present invention, see Figures 3A, B, C, 4D, E, F I will explain based on this.

[0032] As shown in Figure 3A, the workpiece 5, which is temporarily fixed to the receiving jig 8, is transported to a predetermined position and positioned. Above the workpiece 5 of the upper and lower unit 34, the chuck jaws 30 grip the outer wall of the mask spring 1. When the chuck jaws 30 open, the inner wall of the mask spring 1 is guided by the guide pin 20 and falls freely due to its weight, contacting the upper surface of the retaining jaws 21.

[0033] As shown in Figure 3B, when the retaining claw 21 is lowered, the conical tapered surface of the recess 26 of the guide pin 20 comes into contact with the spherical tip portion 9.

[0034] As shown in Figure 3C, the centering member 23 and assembly member 22 of the assembly unit 36 ​​are then lowered together, and the centering member 23 engages with the guide pin 20 to center it. Subsequently, the retaining claws 21 are opened, and the mask spring 1 is allowed to free-fall while being centered, and then centered and placed on the spherical tip 9 of the workpiece 5.

[0035] As shown in Figure 4D, the assembly member 22 is then lowered, its lower end contacting the mask spring 1, expanding the inner diameter of the mask spring 1, and transferring the mask spring 1 to the leg portion 6.

[0036] As shown in Figure 4E, the assembly member 22 is then raised. Subsequently, the retaining claws 21 of the upper and lower units 34 are closed to grip the outer wall of the guide pin 20, and the suction means 14 is activated, causing the frustoconical portion 25 of the guide pin 20 to be attracted to the recess 26 of the centering member 23, thereby raising the assembly member 22 and the centering member 23. As the assembly member 22 and the centering member 23 rise, the guide pin 20 is returned to its original position.

[0037] As shown in Figure 4F, the operation of the suction means 14 is then stopped, the assembly member 22 and the centering member 23 are separated from the guide pin 20, and raised.

[0038] In the elastic ring assembly device of this embodiment, the guide pin 20 is gripped by the retaining claw 21, centered with the centering member 23 and the workpiece 5, and the guide pin 20 is held in a vertical position. As a result, there is no misalignment or tilting between the workpiece 5 and the guide pin 20. Therefore, the mask spring 1 can be transferred to the leg portion 6 of the workpiece 5 while expanding in a horizontal position, and the pressing force applied to the spherical tip portion 9 of the workpiece 5 can be reduced, allowing for temporary assembly without damaging the workpiece 5 (corresponding to the electrode portion of the element).

[0039] According to the elastic ring assembly device of this embodiment, the inner diameter of the mask spring 1 is restricted by the outer diameter of the guide pin 20 and set on the retaining claw 21. As a result, the outer diameter of the guide pin 20 does not wear down rapidly, the mask spring 1 is stably restricted to a horizontal position, and the workpiece 5 can be guided and transferred to the spherical tip portion 9 without getting caught.

[0040] In the elastic ring assembly device of this embodiment, the ring-shaped end face (a flat surface with uniformity all around) 221 at the lower end of the assembly member 22 presses against the mask spring 1, and the mask spring 1 is fitted into the spherical tip portion 9. As a result, the mask spring 1 is assembled while being pressed against the workpiece 5 and expanding in diameter, without tilting, while maintaining a horizontal position.

[0041] According to the elastic ring assembly device of this embodiment, the mask spring 1 is guided axially by a straight guide pin 20, so that the mask spring 1 is pressed directly against the leg portion 6 of the workpiece 5 (equivalent to an element) in a horizontally restricted position and expands in diameter. Therefore, when transferring the mask spring 1 while expanding its diameter, the mask spring 1 does not tilt, and since only the weight of the guide pin 20 acts on the spherical tip portion 9 of the leg portion 6, frictional resistance between the mask spring 1 and the spherical tip portion 9 of the workpiece 5 can be reduced, and damage to the workpiece 5 by the guide pin 20 can be minimized without the problem of the wound end of the mask spring 1 digging into the leg portion 6 of the workpiece 5.

[0042] The elastic ring assembly device of this embodiment has a rotation function that rotates the workpiece 5 and the receiving jig 8 together. As a result, when temporarily assembling the mask spring 1, rotating the workpiece 5 in the opposite direction to the spring winding direction has the effect of loosening the spring winding force of the mask spring 1 that is in contact with the workpiece 5, and the pressing force required to expand the diameter of the mask spring 1 can be reduced. As a result, even if the spring winding force of the mask spring 1 is uneven, the pressing force can be set to a small value and the workpiece 5 can be transferred, so there is no concern of applying excessive pressing force to the legs 6 of the workpiece 5, and damage to the workpiece 5 can be reduced.

[0043] The problem of the inner end of the mask spring easily digging into the outer surface of the spherical tip of the workpiece in the gap between the workpiece and the mask spring during mask spring fitting has been resolved. The elastic ring assembly device of this embodiment includes a receiving jig 8 that fixes the workpiece 5 and allows the workpiece to rotate as a whole. When the chuck jaws 30 release their grip on the mask spring 1 above the workpiece, the outer wall of the guide pin 20 guides the mask spring 1 and allows it to fall by gravity onto the holding jaws 21. When the holding jaws 21, which can grip and move up and down the guide pin 20, open, the mask spring 1, guided by the outer wall of the guide pin 20, falls freely and comes into contact with the spherical tip portion 9 of the workpiece 5. A cylindrical assembly member 22 that slides against the outer wall of the centering member 23 descends and presses the mask spring 1 in the direction of the axial line, temporarily fixing the mask spring 1 to the upper end of the workpiece 5 while expanding the inner diameter of the mask spring 1. In this way, the guide pin 20 restricts the mask spring 1 to a horizontal position, and the assembly member 22 ensures both the centering of the mask spring 1 and its press-fitting into the workpiece 5.

[0044] In the assembly process following the actual configuration described above, a final assembly process is provided in which a pressing member (not shown), whose dimensions match those of the inner diameter after the elastic ring has been temporarily assembled, is used to press the mask spring to a predetermined position on the element and press it into place to the correct size.

[0045] (Comparative form) Next, this embodiment will be described in comparison with several comparative embodiments with reference to Figures 11 to 14. The first comparative configuration is shown in Figure 11. In the first comparative configuration, a tapered pin 50, whose outer diameter increases as it approaches the workpiece, descends by the operation of an upper and lower unit (not shown) and contacts the spherical tip 9 of the workpiece 5. Next, the mask spring 51 is guided by the outer circumferential wall of the tapered pin 50, and the mask spring 51 engages with the spherical tip 9 of the workpiece 5. The chuck jaws 60 are pressed against the mask spring 51, and the chuck jaws 60 press the mask spring 51 against the spherical tip 9 of the workpiece 5.

[0046] In the first comparative configuration, the structure involves the inner diameter of the mask spring 15 contacting the tapered portion of the tapered pin 50 to expand its diameter, which means that the outer diameter of the tapered pin 50 is prone to rapid wear. Furthermore, if the outer diameter of the tapered pin is thin, the mask spring cannot be expanded, causing the mask spring to catch on the spherical tip portion 9 of the workpiece leg portion 6, resulting in a problem where the mask spring cannot be transferred to the leg portion 6.

[0047] At this time, the axial pressure applied by the chuck jaws 60 tends to be insufficient, resulting in insufficient expansion of the mask spring 51. If the expansion of the mask spring 51 is insufficient, it becomes difficult to move it to the temporary assembly position.

[0048] In the second comparative configuration, as shown in Figure 12, two chuck jaws 60 that clamp the workpiece from both sides in a V-shape are brought into contact with the tapered portion of the tapered pin 50, and the mask spring 51 is expanded in diameter while transferring the workpiece to the spherical tip portion 9 (the first comparative configuration is similar). According to the second comparative configuration, the mask spring 51 can easily escape into the gap between the two divided chuck jaws 60.

[0049] As a result, the mask spring 51 is prone to tilting, and the axial alignment in the direction of compression is insufficient. Therefore, failure to transfer the mask spring is likely to occur.

[0050] In the third comparative configuration, as shown in Figure 13, if the axis centerline 54 of the tapered pin 50 is misaligned δ with the axis centerline 55 relative to the leg portion 6 of the workpiece 5, pressing the chuck jaws 60 will generate excessive pressure, making it easy for the workpiece to crack 59 or break. Consequently, poor transfer of the mask spring is likely to occur.

[0051] In the fourth comparative configuration, as shown in Figure 14, when the tapered pin 50 causes the axis centerline 55 of the workpiece 5 to tilt θ as shown by the axis centerline 56, the mask spring 51 tilts when the chuck jaws 60 press against it, applying excessive pressure to the head of the workpiece 5, which makes the workpiece 5 prone to cracking or damage 59. Consequently, poor transfer of the mask spring is likely to occur, resulting in defective products.

[0052] Furthermore, in all of the above comparison forms from the first to the fourth, the mask spring is temporarily assembled (temporarily press-fitted) using a tapered pin. However, when transferring the mask spring 51 while expanding its diameter with the tapered pin 50, the mask spring 51 tends to tilt in the gap between the tapered pin and the spherical tip 9 of the workpiece 5. As a result, the inwardly wound end of the mask spring 51 tends to dig into the outer surface of the spherical tip 9 of the element's head, further increasing the frictional resistance between the mask spring and the element, making the workpiece prone to cracking or damage.

[0053] Thus, in the devices described in the first to fourth comparative configurations, it is difficult to automate the temporary assembly process (temporary press-fitting process) of the mask springs. Currently, this process is handled manually, which takes a lot of time and significantly reduces production efficiency.

[0054] The elastic ring assembly device of the present invention has a guide pin having a recess (26) at its lower end that can be positioned at the tip of the workpiece, and a positioning portion (25) at its upper end that can engage with the positioning portion (24) of the centering member. As a result, the guide pin is centered by the centering member 23 and the workpiece 5. Therefore, the guide pin is held vertically.

[0055] In the elastic ring assembly device of the present invention, the guide pin is cylindrical and has an outer diameter smaller than the inner diameter of the elastic ring in its normal state. Therefore, the elastic ring can be allowed to free-fall while being guided by the outer wall of the guide pin.

[0056] The present invention's method for assembling an elastic ring includes, in addition to the steps of the above-described method for assembling an elastic ring, a step of stopping the elastic ring from falling by gravity midway. The process then involves dropping the elastic ring by gravity again, The process may then include the step of guiding a guide pin inside the assembly member so that the assembly member, which moves along a relative axis, comes into contact with the elastic ring at its circumferential end face (221).

[0057] (Other embodiments) In the present invention, the shape of the elastic ring corresponding to the mask spring described above is not limited to the shape of the embodiment described above. The above-described embodiment describes an apparatus up to the step of temporarily assembling the mask spring to the detection electrode portion of the element corresponding to the workpiece.

[0058] The above-described embodiment explains the process of temporarily assembling a mask spring to the detection electrode portion of an element corresponding to a workpiece. A subsequent process is a mask spring press-fitting process (not shown), in which the mask spring is pressed in to the assembly position of the element by pressing it with a punch. As stated above, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its essence. [Explanation of Symbols]

[0059] 1. Mask spring (elastic ring) 5 Workpieces (Elements) 6 legs, 8. Receiving fixture, 9 tip bulb, 10. Main unit of the device, 14 suction means; 20 guide pins 21 retaining claw, 22 Assembly components, 23 Centering member, 24 Tapered inner wall surface (positioning part), 25. Truncated cone section (positioning section), 26 Recess (positioning part), 30 chuck jaws, 34 upper and lower units, 36 assembly units.

Claims

1. An elastic ring assembly device for temporarily fixing an elastic ring to the tip of a columnar workpiece, A receiving jig (8) that temporarily fixes one end of the workpiece (5) and allows the workpiece to rotate as a whole, A chuck jaw (30) capable of gripping an elastic ring (1) for temporary fixing to the other end of the workpiece is located above the workpiece. A guide pin (20) that guides the elastic ring along its outer wall when the chuck jaws are released, allowing it to fall by gravity, The aforementioned guide pin is gripped and raised / lowered by a retaining claw (21), A cylindrical assembly member (22) that can press an elastic ring guided to the upper end of the workpiece in the axial direction, and temporarily fixes the elastic ring to the upper end of the workpiece while expanding the inner diameter of the elastic ring when pressed, A centering member (23) is slidable in the axial direction within the assembly member, capable of centering the workpiece and the guide pin, and has an internal air passage (28), An elastic ring assembly device comprising a suction means (14) capable of sucking the guide pin through the air passage.

2. The elastic ring assembly device according to claim 1, wherein the guide pin has a recess (26) at its lower end that can be positioned at the tip of the workpiece, and a positioning portion (25) at its upper end that can engage with the positioning portion (24) of the centering member.

3. The elastic ring assembly device according to claim 1, wherein the guide pin is cylindrical and has an outer diameter smaller than the inner diameter of the elastic ring in its normal state.

4. A method for assembling an elastic ring, in which an annular elastic ring with a variable inner diameter is temporarily fixed to the tip of a columnar workpiece, A step of rotating the workpiece (5), which is positioned on the receiving jig (8), around its axis, The process involves attaching a centered guide pin (20) to the tip of the workpiece, A step of guiding the elastic ring (1) that is falling by gravity along the guide pin to the tip of the workpiece using the guide pin, The process involves the assembly member (22) pressing the elastic ring against the tip of the workpiece during workpiece rotation, thereby increasing the inner diameter of the elastic ring and temporarily fixing the elastic ring to the tip of the workpiece, A method for assembling an elastic ring, comprising the step of releasing the pressure on the elastic ring by the assembly member after temporarily fixing the elastic ring to the tip of the workpiece.

5. The process of stopping an elastic ring that is falling by gravity midway, The process then involves dropping the elastic ring by gravity again, The method for assembling an elastic ring according to claim 4, further comprising the steps of: guiding a guide pin inside the assembly member so that the assembly member moves along a relative axis and contacts the elastic ring with its circumferential end face (221).

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