JP2004257462A - Nitriding treatment holder for metal ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nitriding treatment holder capable of easily attaching/detaching a metal ring and holding the metal ring of different diameter without performing any special operation. <P>SOLUTION: The nitriding treatment holder is used for nitriding a metal ring 2 which is formed in an endless strip shape by welding end parts of a steel sheet and also formed in an outwardly projecting arc-shaped shape in sectional view at a center part along the width direction. The holder comprises a frame body 3 capable of freely inserting the metal ring 2 in the radial direction, and a plurality of holding members 3 which are attached to the frame body 3, and pressed against a top part of the arc-shaped part on an outer circumferential surface of the metal ring 2, and hold the metal ring 2 so as to be pressed from a plurality of parts of an outer circumferential surface and deflected. A holding member 4 is attached to two side surfaces facing each other of the frame body 3 and a bottom surface, and the metal ring 2 is attachable/detachable to/from the holding member 4 from an upper part of the frame body 3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a jig for holding a metal ring used as a material of an endless metal belt used for a continuously variable transmission or the like when nitriding the metal ring.
[0002]
[Prior art]
2. Description of the Related Art A belt of a continuously variable transmission (CVT) used as a transmission of an automobile or the like is configured by a laminated ring formed by laminating a plurality of metal rings in a thickness direction thereof.
[0003]
The metal ring is formed by cutting a cylindrical drum formed by welding the ends of a thin plate made of a steel material such as maraging steel or stainless steel into a predetermined width to obtain an endless belt-shaped ring. It is rolled to a thickness, and a perimeter correction for a predetermined perimeter is performed. Then, the metal ring whose circumference has been corrected is subjected to an aging treatment and a nitriding treatment to improve hardness and wear resistance, and then a plurality of metal rings each having a slightly different circumference are laminated on each other. The lamination ring is formed.
[0004]
As the nitriding treatment, a gas nitriding method, a gas soft nitriding method, and the like, which are performed by holding the metal ring in an atmosphere containing a predetermined concentration of ammonia for a predetermined time, are known. In the gas nitriding method or the gas nitrocarburizing method, it is preferable that the entire metal ring is exposed to the atmosphere in order to uniformly nitride the metal ring.
[0005]
Therefore, a jig shown in FIG. 5 is conventionally known as a jig for holding the metal ring when nitriding the metal ring by the gas nitriding method or the gas nitrocarburizing method. The nitriding jig shown in FIG. 5 includes a pair of suspension members 12 provided at predetermined intervals above and below a standing pole 11, and each suspension member 12 is shown in a side view in FIG. 6. As shown in the drawing, the front end portion 13 is provided with a holding member 14 having a V-shape in plan view. The holding member 14 can press the metal ring 2 in the width direction by pressing against the inner peripheral surface of the metal ring 2, and hold the metal ring 2 in a state where tension is applied to the metal ring 2. A mesh member 15 made of pure Ni is disposed on the holding member 14, and the holding member 14 holds the metal ring 2 via the mesh member 15 (see Patent Document 1).
[0006]
According to the conventional nitriding jig, there are few portions where the metal ring 2 comes into contact with the holding member 14, and the mesh member 14 made of pure Ni which is not subjected to nitriding itself is disposed in this portion. . Therefore, non-uniform nitriding of the metal ring 2 can be reduced.
[0007]
However, the above-mentioned conventional nitriding jig has a complicated structure, and a nitriding jig with a simpler configuration and easy attachment and detachment of the metal ring 2 is desired.
[0008]
In recent years, it has been studied to apply the CVT to a larger vehicle model. However, in the conventional nitriding jig, if the diameter of a metal ring is increased for the CVT mounted on a large vehicle model, An operation such as increasing the interval between the suspension members 12 is required. Therefore, even if the setting is made to use the small-diameter metal ring 2 for CVT of a small vehicle model, the nitriding treatment can be applied to the larger-diameter metal ring without requiring any special operation. Tools are desired.
[0009]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-161314
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a nitriding jig which can easily attach and detach a metal ring and can hold metal rings having different diameters without performing a special operation.
[0011]
[Means for Solving the Problems]
In order to achieve this object, the metal ring nitriding jig of the present invention is formed by forming a steel material into an endless band shape, and giving an arc-shaped cross-section that is outwardly convex at the center along the width direction. A jig used for nitriding the metal ring, wherein the metal ring is inserted radially into the frame, and the metal ring is attached to the frame, and the outer peripheral surface of the metal ring is attached to the arc-shaped top. And a plurality of holding members for pressing and pressing the metal ring from a plurality of locations on the outer peripheral surface to hold the metal ring in a bent state.
[0012]
The metal ring is formed by rolling an endless belt-shaped ring made of a steel material such as maraging steel or stainless steel to a predetermined thickness, and further correcting the circumferential length to a predetermined circumferential length. The portion is provided with an outwardly convex arcuate cross-sectional shape. Therefore, in the nitriding jig of the present invention, the plurality of holding members attached to the frame body in which the metal ring is freely insertable in the radial direction are provided on the outer peripheral surface of the metal ring at the arc-shaped top. The metal ring can be pressed and pressed from a plurality of locations on the outer peripheral surface to hold the metal ring in a bent state.
[0013]
According to the nitriding jig of the present invention having such a configuration, the metal ring is inserted into the frame body in a bent state, and then the bent state is released and the ring is returned to an annular shape, so that the metal ring can be easily formed. The metal ring can be held by the holding member, and the metal ring can be easily extracted by the reverse operation, so that the metal ring can be easily attached and detached.
[0014]
Further, in the nitriding jig of the present invention, since the plurality of holding members are pressed against the arc-shaped tops on the outer peripheral surface of the metal ring, the side edges of the metal ring are attached to the holding member and the frame. The metal ring is held by the holding member 4 without any contact, so that the side edge can be uniformly nitrided. When the metal rings are stacked on each other to form a laminated ring, tension is applied to the side edges, and it is not preferable that the nitride layer is formed unevenly on the side edges. However, according to the nitriding jig of the present invention, since the side edges of the metal ring can be uniformly nitrided as described above, the concentration of the tension can be prevented.
[0015]
On the other hand, the portion of the outer peripheral surface of the metal ring that comes into contact with the holding member is considered to be non-uniform, but the outer peripheral surface of the metal ring is formed by laminating the metal rings with each other to form a laminated ring. When configured, it is shielded by the adjacent metal ring and never exposed. Therefore, the laminated ring can be used for CVT without any problem.
[0016]
Further, in the nitriding jig of the present invention, since the metal ring is held as described above, if the size of the frame is set in advance so as to be adapted to the small-diameter metal ring, it is possible to change the vehicle type. Accordingly, even when the metal ring has a large diameter, the metal ring can be attached and detached without performing any special operation on the jig itself, simply by increasing the amount of deflection of the metal ring.
[0017]
In the nitriding jig of the present invention, the holding member is attached to two opposing side surfaces and a bottom surface of the frame, and the metal ring is detachably attached to the holding member from above the frame. It is preferred that
[0018]
In addition, by disposing the holding member as described above, the metal ring is prevented from falling off from the side surface or the bottom surface of the frame body due to its own weight, and the metal ring is securely held. Can be.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a side view showing a part of a nitriding jig according to one embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is an explanatory cross-sectional view of a nitriding jig according to still another embodiment.
[0020]
The nitriding jig 1 of the present embodiment shown in FIGS. 1 and 2 is applied to, for example, a metal ring 2 manufactured as follows.
[0021]
When the metal ring 2 is manufactured, first, ends of thin plates made of a steel material such as maraging steel or stainless steel are welded to each other to form a cylindrical drum, and the drum is partially heated by heat at the time of the welding. The first solution treatment is performed in order to homogenize the hardened hardness. Next, the drum after the solution is cut into a predetermined width to form an endless metal ring 2, and the metal ring 2 is rolled to a predetermined thickness. Next, a second solution treatment is performed on the rolled metal ring 2 in order to recrystallize the rolled structure and restore the shape of the metal structure deformed by rolling. The metal ring 2 to be subjected to the aging process and the nitriding process is formed by performing the circumferential length correction.
[0022]
In the rolling, the metal ring 2 is sandwiched between a pair of rolling rollers disposed between the two tension rollers while the metal ring 2 is driven to rotate by being wound around the pair of tension rollers, and the metal ring 2 is applied. This is done by pressing. At this time, in order to prevent the metal ring 2 from dropping, one tension roller is displaced with respect to the other tension roller, and tension is applied to the metal ring 2.
[0023]
Further, the circumferential length correction is performed by rotating one of the tension rollers with respect to the other tension roller while rotating the metal ring 2 around a pair of tension rollers and rotating the metal ring 2 so that the metal ring 2 has a predetermined circumferential length. It is carried out by applying tension until it becomes. Alternatively, a straightening roller is provided between the pair of tension rollers, and the straightening roller is displaced in a direction orthogonal to the direction of movement of the displacing tension roller to increase the tension until the metal ring has a predetermined circumferential length. It is performed by giving.
[0024]
Therefore, at the time of the rolling or the perimeter correction, a roller having an arc-shaped cross-section that is outwardly convex at the center in the thickness direction is used as the tension roller or the correction roller on the displaced side. Thus, the shape of the roller is transferred to the metal ring 2. As a result, the metal ring 2 is provided with an arc-shaped cross section that is outwardly convex at the center in the width direction.
[0025]
The metal ring 2 has an arcuate shape in cross section, so that when the plurality of metal rings 2 are stacked to form a stacked ring, adjacent metal rings 2 are engaged with each other and stacked. Maintenance of the state becomes easy.
[0026]
The nitriding jig 1 according to the present embodiment includes a frame 3 in which the metal ring 2 is freely insertable in the radial direction thereof, and is attached to the frame 3 to press the metal ring 2 from a plurality of locations on the outer peripheral surface. A plurality of holding members for holding the metal ring in a bent state.
[0027]
The holding member 4 is a round bar that extends along the length direction of the rectangular parallelepiped frame 3, and has a predetermined space near the center between two opposing side surfaces of the frame 3 and the bottom surface. And they are attached two by two. Therefore, as shown by an arrow in FIG. 2A, the metal ring 2 can be inserted into the frame 3 from above, where the holding member 4 is not provided.
[0028]
When storing the metal ring 2 in the nitriding jig 1, the metal ring 2 is bent so that the holding member 4 attached to one side of the frame 3 and the side opposite to the side face are attached to the holding member 4. The metal ring 2 is inserted into the frame 3 in a state where the width of the metal ring 2 is smaller than the distance between the holding member 4 and the metal ring 2 in the frame 3. As a result, the metal ring 2 returns to an annular shape by its own elastic force, and is held by the holding member 4.
[0029]
At this time, since two holding members 4 are attached at predetermined intervals near the center between the two opposing side surfaces of the frame 3 and the bottom surface, the metal ring 2 is attached to the outer peripheral surface. It can be held in a state where it is pressed and bent from a plurality of places. At the same time, the holding member 4 can prevent the bent metal ring 2 from falling off from the side surface or the bottom surface of the frame 3. Thus, in the nitriding jig 1, a plurality of metal rings 2 can be stored along the length of the frame 3.
[0030]
Although the metal ring 2 held by the holding member 4 is pressed by the holding member 4 as described above, the holding force of the holding member 4 is extremely weak. Therefore, in the present embodiment, the metal ring 2 is in a state of a free circle having an annular shape close to a perfect circle due to its own elastic force.
[0031]
When extracting the metal ring 2 from the nitriding jig 1, the metal ring 2 held by the holding member 4 is bent so that the holding member 4 attached to one side surface of the frame 3 is removed. By setting the width to be smaller than the distance between the holding member 4 attached to the side surface opposite to the side surface, the frame body 3 can be separated from the outside.
[0032]
By the way, since the metal ring 2 is provided with an arcuate shape in a cross section that is outwardly convex at the central portion along the width direction as described above, the nitriding jig 1 of the present embodiment has the configuration shown in FIG. As shown in b), the holding member 4 is pressed against the arc-shaped top on the outer peripheral surface of the metal ring 2. As a result, in the nitriding jig 1, the metal ring 2 is held by the holding member 4 in a state where the side edge of the metal ring 2 does not contact the holding member 4 and the frame 3 at all, and the side edge is uniformly Can be nitrided.
[0033]
Since the side edges are exposed when the metal rings 2 are stacked on each other to form a laminated ring, if there is a portion where nitriding is not uniform at the side edge, tension concentrates on that portion. It is concerned. However, according to the nitriding jig 1 of the present embodiment, as described above, the side edge of the metal ring 2 can be uniformly nitrided, so that the concentration of the tension can be prevented.
[0034]
On the other hand, it is conceivable that the portion of the outer peripheral surface of the metal ring 2 that is in contact with the holding member 3 may have non-uniform nitriding, but the outer peripheral surface of the metal ring 2 may When configured, it is shielded by the adjacent metal ring 2 and is not exposed. Therefore, the laminated ring can be used for CVT without any problem.
[0035]
In the nitriding jig 1 of the present embodiment, since the metal ring 2 is attached to and detached from the holding member 4 as described above, the size of the frame 3 is set to a size corresponding to the small-diameter metal ring 2. If this is done, it can be applied without performing any special operation when nitriding the larger diameter metal ring 5. In this case, as shown in phantom lines in FIG. 2, the upper part of the metal ring 5 projects above the frame 3, but the lower part is held by the holding member 4 in substantially the same shape as the small-diameter metal ring 2. . Therefore, there is no particular problem in nitriding the large-diameter metal ring 5.
[0036]
The cross-sectional shape of the holding member 4 is not particularly limited, but by making it circular as shown in FIG. 2 (a), the area in contact with the outer peripheral surface of the metal ring 2 is reduced. This is preferable because it is possible to avoid an excessive surface pressure when pressing the surface.
[0037]
In the embodiment, the metal ring 2 is directly held by the holding member 4 attached to the frame 3. However, as shown in FIG. 3, meshes are respectively attached to two holding members 4, 4 attached at predetermined intervals in the vicinity of the center between the two opposite side surfaces of the frame body 3 and the bottom surface. The member 4a may be stretched so that the metal ring 2 is held by the mesh member 4a. Since the metal ring 2 is held by the mesh member 4a, the portion in contact with another member is further reduced, and the portion where nitriding is insufficient can be reduced.
[0038]
Further, in the embodiment, the metal ring 2 is held by the holding member 4 attached to the frame 3 in a state of the free circle. However, as shown in FIG. 4, the interval between the two opposing side surfaces of the frame 3 is made narrower than that in FIG. Two such nitriding jigs 1a may be arranged in parallel to form the nitriding jig 1. By doing so, the volume required for holding one metal ring 2 can be reduced, and more metal rings 2 can be held in a predetermined volume.
[Brief description of the drawings]
FIG. 1 is a side view showing one embodiment of a nitriding jig of the present invention.
2A is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. 2B is an explanatory cross-sectional view showing an enlarged main part of FIG.
FIG. 3 is a sectional view showing another embodiment of the nitriding jig of the present invention.
FIG. 4 is a sectional view showing still another embodiment of the nitriding jig of the present invention.
FIG. 5 is a front view showing a configuration example of a conventional nitriding jig.
FIG. 6 is an explanatory cross-sectional view showing an enlarged main part of the nitriding jig shown in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Nitriding process jig, 2, 5 ... Metal ring, 3 ... Frame, 4 ... Holding member.

Claims (2)

A jig used for nitriding a metal ring having a steel material formed in an endless band shape and having an arcuate cross-sectional shape that is outwardly convex at the center along the width direction,
The metal ring is attached to the frame body that can be inserted in the radial direction, and the metal ring is pressed against the arc-shaped top on the outer peripheral surface of the metal ring, and the metal ring is pressed from a plurality of positions on the outer peripheral surface. And a plurality of holding members for holding the metal ring in a bent state. The holding member is attached to two opposing side surfaces and a bottom surface of the frame, and the metal ring is detachable from the holding member from above the frame. Item 3. A jig for nitriding a metal ring according to Item 1.

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