KR20020027186A - Sliding key, sliding key structure, and pulley unit - Google Patents

Abstract

PURPOSE: A slide key, a slide key structure, and a pulley unit are provided to perform force fitting or fitting without generation of burr and galling when the slide key is mounted to a groove of a rotating shaft. CONSTITUTION: A slide key(1) is used for engaging a slide cylinder in the axial direction of a rotating shaft slidably and follow rotatably, and is a complex integrated molded article of a metal molded body(2) and a resin body(3). A corner part of a slide key bottom fitting with the groove part formed in the outer periphery of the rotating shaft is formed on the resin body longitudinally.

Description

Sliding key, sliding key structure and pulley unit {SLIDING KEY, SLIDING KEY STRUCTURE, AND PULLEY UNIT}

The present invention provides a sliding key, a sliding key structure, and a pulley unit using the sliding or sliding key structure, particularly a continuously variable transmission, which are made of a composite molded product of a metal molded body and a resin molded body suitable for use in a special environment such as high temperature lubrication. It is about.

As a pulley structure of a continuously variable transmission using a sliding key, a fixed pulley which rotates integrally with a rotating shaft and a pulley structure of a continuously variable transmission that engages a movable pulley having a slide cylinder by a sliding key are known (Japanese Patent Laid-Open No. 8-219258). ).

12, the pulley structure and the sliding key of the continuously variable transmission will be described. 12 is an axial half sectional view of the pulley structure.

The rotary shaft 4 driven by the rotary shaft by the engine (not shown) is supported by the transmission body by the bearings 5a and 5b. The rotating shaft 4 is integrally formed to protrude outward and has a fixed pulley 7 formed therein, and in the end portion 4a formed at the outer periphery of the rotating shaft 4, it is concave in the shape of a long hole in the longitudinal direction thereof. The grooves 4b are formed at equal intervals in the circumferential direction. A movable pulley 8 having a slide cylinder 8a which is fitted with a sliding key 1 in this groove portion 4b and which is slidable so as to be able to move with respect to the fixed pulley 7 by the sliding key 1. Is hooked up. The sliding key 1 fitted to the groove portion 4b is mainly required for rotation stop or power transmission, or an axial reciprocating function is also required as an additional function. In addition, in FIG. 12, "9" is a V-belt which is hanged between the fixed pulley 7 and the movable pulley 8. In FIG.

Conventionally, the sliding key 1 is mainly formed of metals and resin materials having a small coefficient of friction. However, the sliding key made of metal tends to have a large frictional resistance due to the sticking or rusting of the metals, which is likely to cause a malfunction or malfunction. The sliding key has a problem of shortening of life due to melting, deformation, or high frictional resistance.

For example, a metal sliding key has excellent rigidity against a load, but when the key groove on the slide cylinder is a metal, the metal slides with each other. Or rust may cause sliding resistance to increase, resulting in malfunction or inoperability. For example, a resin made of a material in which a polyimide resin, a polytetrafluoroethylene resin and graphite are mixed, or a material in which a polyether ether ketone resin, a carbon fiber and a polytetrafluoroethylene resin are mixed may be used. Although the coefficient of friction in the sliding part can be made small by the selection of a mixed material such as graphite or graphite, the durability life is shortened because melting or deformation of the resin is likely to occur in a high temperature and high load operating environment.

As a sliding key to solve the above problem, a sliding key of a composite molded article of a metal molded body and a resin molded body is known (Japanese Patent Laid-Open No. 2000-55067). That is, this sliding key is to secure rigidity with a metal molded body, and to form a sliding part with a resin molded body to secure a low sliding resistance even in a high temperature and high load use environment.

The sliding key 1 of the composite integrally molded article is a metal molded portion that fits into the groove portion 4b formed on the outer circumference of the end portion 4a of the rotating shaft, and a portion that slides with the inner circumferential groove portion of the slide barrel 8a is a resin molded body. It is possible to obtain a resin molded body by injection molding or compression molding by disposing a metal molded body in the mold so as to be.

In addition, since the fitting part of the sliding key 1 is press-fitted to the groove part 4b, the chamfering process is performed in the corner part of a bottom part. If the chamfering process is not performed, problems such as being corrugated, fitting at an angle, or taking time in the fitting step may occur when press-fitting the groove 4b.

However, a sliding key made of a composite molded product of a conventional metal molded body and a resin molded body requires a metal molded body to be placed in an injection molding die, which results in a large mold structure and complicated manufacturing equipment, resulting in high manufacturing costs. There is a problem of getting expensive.

In addition, the sliding key of the composite molded article of the metal molded body and the resin molded body inserts the metal molded body and generates burrs at the boundary between the metal molded body and the resin molded body. In addition, there is a problem that it is difficult to remove the burrs inevitably generated when the composite molded article is formed. This burr increases the frictional resistance or decreases the sliding performance. If the burr is to be removed, the number of work steps increases, resulting in problems such as low productivity and high manufacturing costs.

In addition, the chamfering of the corner portion for press-fitting into the groove portion 4b is performed by grinding or milling cutter, but there is a problem that productivity decreases and manufacturing cost increases because the number of working steps increases. .

In addition, there is a problem that rust occurs in the machined portion by machining a metal molded body subjected to surface treatment such as plating.

SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and in a sliding key that operates stably without causing a malfunction or malfunction even under a high temperature and high load use environment, there is no occurrence of burrs and a ring when mounted on a groove portion. It is an object of the present invention to provide a sliding key and a sliding key structure that can be press-fitted or fitted, and a pulley unit using the sliding key and the sliding key structure.

1 is an external perspective view showing a sliding key of the first embodiment, b is an exploded perspective view of a,

2 a and b are exploded perspective views showing a modification of Fig. 1, respectively;

3 is an external perspective view showing a sliding key of the second embodiment, b is an exploded perspective view of a,

4A and 4B are exploded perspective views showing modified examples of FIG. 3, respectively.

5 a, b, c, d is an external perspective view showing a modified example of FIG.

6 is an external perspective view showing a sliding key of the third embodiment, b is an exploded perspective view of a,

A, b, c, d, e of Figure 7 is an external perspective view showing a modification of Figure 6,

8 is a view showing an example of a sliding key integrally formed by screwing in Figure 8,

9 is a perspective view of the sliding key shown in FIG. 8;

10 is a view showing an example of a sliding key molded integrally by welding;

11 is an exploded perspective view of each component shown in FIG. 10;

12 is an axial half sectional view of the pulley structure;

13 is a view showing a state of use of the sliding key,

14 is a view showing an example of a sliding key;

15 is a view showing an example of a sliding key shown as a comparative example;

16 is a perspective view of a resin molded article,

17 is a view for explaining a sliding key structure;

18 is a perspective view and a sectional view of the sliding key structure shown in FIG. 17;

19 is a view for explaining another sliding key structure;

20 is a perspective view and a sectional view of the sliding key structure shown in FIG. 19;

21 is a view showing a repeated shear fatigue tester and

22 is a diagram illustrating a friction tester.

* Explanation of symbols for main parts of the drawings

1: sliding key 2: metal molding

3: resin molded body 4: rotating shaft

5: bearing 6: spacer ring

7: fixed pulley 8: movable pulley

9: V belt

The first sliding key according to the present invention is slidable in the axial direction of the rotating shaft, and the sliding key is engaged with the slide cylinder so as to be able to follow the rotation, and the sliding key provided with the sliding shafts on both sides of the rotating shaft or the slide passage is provided with the respective sliding keys separately. The metal molded body and the resin molded body are integrally bonded to each other, and at least the sliding parts of both sides are formed of the resin molded body.

Further, the metal molded body and the resin molded body are bonded together by interposing an adhesive agent.

Moreover, the said adhesive is an epoxy type adhesive, It is characterized by the above-mentioned.

In addition, the adhesive is characterized in that the molten fluorine resin in the form of a film.

In addition, the resin molded article having a portion complementarily fitted to the recess formed in the metal molded article is press-fit-fitted to be integrally joined.

The side face of the metal molded body is integrally joined to each other by the resin molded body integrally formed with the sliding parts on both side surfaces thereof.

The first sliding key is a composite in which the metal molded body and the resin molded body are separately joined together, and the sliding parts of at least both sides are formed of the resin molded body so that stable operation can be ensured even in a high temperature and high load operating environment. At the same time, it is possible to reuse metal moldings that are inexpensive, labor-free, and intact in maintenance.

In addition, the adhesive is interposed between the metal molded body and the resin molded body or press-fitted the resin molded body having a portion complementarily fitted to the recess formed in the metal molded body, or on both sides of the molded body. The metal molded body and the resin molded body can be easily joined together by sandwiching the side surfaces of the metal molded body from both sides by the resin molded body in which the sliding part is integrally formed. It is also possible to combine a plurality of such integral bonding means.

A second sliding key according to the present invention is characterized in that the metal molded body and the resin molded body are integrally joined by screwing.

A third sliding key according to the present invention is characterized in that the plurality of resin molded bodies are welded to each other so as to sandwich the metal molded bodies and joined together.

The said 2nd and 3rd sliding key eliminates the burr which generate | occur | produces when integrally forming a conventional sliding key by screwing together the metal molding and resin molding which were manufactured separately, or welding the resin moldings together. Moreover, even in a use environment that slides at a high temperature and a high load, there is no peeling between each other, so that no malfunction or malfunction occurs.

The above-mentioned first, second or third sliding key is characterized in that the metal molded body and the resin molded body are joined to each other by complementary irregularities.

By joining the metal molded body and the resin molded body by the unevenness that complementarily fits together, the metal molded body and the resin molded body can be joined together firmly without shifting. Moreover, positioning at the time of combination becomes easy.

The fourth sliding key according to the present invention is a sliding key which is slidable in the axial direction of the rotating shaft and which engages the slide cylinder so as to be capable of following rotation, wherein the sliding key is a composite molded product of a metal molded body and a resin molded body, and the rotary shaft Or the corner part of the sliding-key bottom part which fits into the groove part recessed in the said slide cylinder is formed by the said resin molding over the longitudinal direction. It is characterized by the above-mentioned.

In addition, the resin molded body is characterized by consisting of a resin composition capable of injection molding.

In addition, the protruding pin trace during injection molding is formed in the resin portion of the bottom surface.

The fourth sliding key is an integrally molded product of a metal molded body and a resin molded body, and the corner portion of the bottom of the sliding key which fits into the groove provided on the outer circumferential part of the rotating shaft is press-fitted into the groove by forming the resin molded body in the longitudinal direction. In this case, since the resin portion starts to come into contact with the groove portion, it is possible to press-in without causing a galling phenomenon or the like. In the case of fitting, the corner portion of the resin molded body is not damaged by providing the corner portion at the bottom of the sliding key.

Moreover, since the corner part used as a chamfer becomes a molded article of a resin molded object, since the chamfering process of a post process is unnecessary, productivity improves and rust does not generate | occur | produce.

The sliding key structure according to the present invention is a sliding key structure which is slidable in the axial direction of the rotating shaft and engages the slide cylinder on the rotating shaft so as to be able to follow the rotating direction, the sliding of the inner surface of the groove portion recessed in the rotating shaft or the slide cylinder. The key sliding portion is made of a resin molded body.

In addition, the resin molded body is characterized in that the molded body of the injection molding resin composition.

Further, the sliding key fitted to the groove portion is characterized in that the sliding key is fitted to the groove portion recessed in the mating slide cylinder or the rotating shaft to be engaged.

In addition, the sliding key fitted to the groove portion is characterized in that the projection is convexly installed on the slide cylinder or the rotating shaft.

The sliding key structure according to the present invention has excellent sliding properties by using the sliding key sliding portion of the inner surface of the groove portion recessed in the rotating shaft or the slide barrel as a resin molded body, so that even in an operating environment that slides at high temperatures and high loads, the sliding key structure is poor. There is no cause of disability. In particular, the resin molded body can be easily formed even in a complicated shape or structure by using a resin molded product capable of injection molding. For this reason, compared with the conventional ball spline, it becomes small in size, light weight, and low cost.

The pulley unit according to the present invention has a plurality of key grooves are formed at appropriate intervals in the circumferential direction of the outer diameter surface of the rotary shaft, and in the interval of the key grooves of the rotary shaft in the circumferential direction of the inner diameter surface of the slide cylinder slides in the axial direction of the rotary shaft. A plurality of key grooves are formed in conformity, and the slide cylinder can follow the rotation shaft by a sliding key fitted to the rotation shaft or the plurality of key grooves of the slide cylinder, or by a sliding key structure that engages the rotation shaft and the slide cylinder. In the pulley unit, which is securely engaged to the rotating shaft and provided with a movable pulley in the slide barrel facing the fixed pulley, the sliding key is formed by any one of the first to fourth sliding keys. It characterized in that the pulley unit having a sliding key structure according to the present invention.

In addition, the pulley unit is characterized in that for the continuously variable transmission.

Since the pulley unit according to the present invention uses the sliding key according to the present invention described above, and has a sliding key structure, a continuously variable transmission having a sliding operation performance in a lubricating atmosphere with a simple structure can be obtained. In addition, compared with the conventional ball spline, it is possible to reduce the size and weight.

The 1st sliding key which concerns on this invention is demonstrated based on FIG. FIG.1 (a), (b) shows the sliding key 1 of 1st Embodiment. The sliding key 1 consists of a metal molded body 2 as a base member and two resin molded parts 3 forming sliding parts on both sides, and a concave step provided on both sides except for the front and rear ends of the metal molded body 2. Each plate-shaped resin molded body 3 is integrally joined to the portion 2b by an adhesive.

Each resin molded part 3 is formed slightly thicker than the step of each step part 2b so as to protrude from each side surface of the metal molded part 2 to form a sliding part. In addition, the axial force applied to the sliding portion is received by the end walls 2b on both sides of the stepped portion 2b so that the shear force does not act on the adhesive surface at the bottom of the stepped portion 2b. have.

As the adhesive that can be used for the first sliding key according to the present invention, an epoxy-based adhesive that is representative of a crosslinking adhesive having excellent heat resistance is used. Instead of the crosslinked adhesive, a film-shaped molten fluororesin may be sandwiched between the adhesive surfaces, and the resin molded body 3 may be joined by heating and melting. As the molten fluororesin, an ethylene tetrafluoroethylene copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, or the like can be used.

2 (a) and 2 (b) show a modification of the first embodiment in the first sliding key according to the present invention. The sliding key 1 of FIG. 2 (a) has a hole 2d complementarily fitted to the bottom of the stepped portion 2b of the metal molded body 2 adhered to each other and to the side surface of each resin molded object 3. And the columnar projections 3e and FIG. 2B are similarly provided with the elongated holes 2e and the wall projections 3f that are complementarily fitted. These fitting holes 2d and 2e and protrusions 3e and 3f can reinforce the bonding by the adhesive.

In addition, by providing the bundles in the projections 3e and 3f with respect to the holes 2d and 2e, it can be firmly joined.

3 (a) and 3 (b) show a second embodiment of the first sliding key according to the present invention. Similarly to the first embodiment, the sliding key 1 also includes a metal molded body 2 as a base member and two resin molded parts 3 forming sliding parts on both sides. In this embodiment, the metal molded body 2 Concave stepped portions 2b are provided on both sides of the front and rear ends and lower portions of the stepped portions, and each resin molded body 3 is press-fitted to each stepped portion 2b and integrally joined to the metal molded body 2. . An adhesive may be used for the bonding surface. Other than that is the same as that of 1st Embodiment.

4 and 5 show a modification of the second embodiment. The modifications of Figs. 4A and 4B are the same as those of the first embodiment shown in Figs. 2A and 2B, respectively, and the stepped portions 2b of the metal molded body 2 are respectively. In the bottom of the mold and the side surface of each resin molded body 3, a hole 2d and a columnar projection 3e to be complementarily fitted, or an elongate hole 2e and a wall projection 3f are provided. Similarly to the modification of the first embodiment, by joining the bundles to the projections 3e and 3f with respect to the holes 2d and 2e, the joints can be firmly joined.

5 (a), 5 (b), 5 (c) and 5 (d) are all tapered in the vertical direction to each resin molded article 3, and FIGS. Each resin molded body 3 is bonded to each other over the entire length of the metal molded body 2 in the up and down direction, and FIGS. 5C and 5D show each resin molded body 3 while leaving the lower part of the metal molded body 2 underneath. It is bonded.

In addition, each modified example shown in FIG. 4 and FIG. 5 may use an adhesive agent for the joining of the metal molded object 2 and each resin molded object 3, and is complementary to the said modified example shown in FIG. The hole 2d and the columnar projection 3e, or the long hole 2e and the wall projection 3f may be used in combination.

6 (a) and 6 (b) show the sliding key 1 of the third embodiment. This sliding key 1 also consists of the metal molded object 2 as a base member and the resin molded object 3 which forms a sliding part similarly to each said embodiment. In this embodiment, both side portions 3g forming the sliding portion of the resin molded body 3 are integrally joined at the ceiling portion 3h, and the concave stepped portions 2g are provided on both side surfaces of the metal molded body 2 except for the front and rear ends. It is fitted to both side portions 3g provided with a bundle , and the metal molded body 2 and the resin molded body 3 are integrally joined together. On the upper surface of the metal molded body 2, a concave stepped portion 2f into which the ceiling portion 3h of the resin molded body 3 is fitted is also provided. Other than that is the same as that of each said embodiment.

7 shows a modification of the third embodiment. (A), (d) and (e) of FIG. 7 are bonded to each resin molded body 3 while leaving the lower part of the metal molded body 2, (b), (c) and (d) of FIG. (e) gives each resin molding 3 the taper of an up-down direction. Also in this modified example, holes 2d and columnar projections 3e or elongated holes 2e and wall projections (2d) to be bonded to the metal molded body (2) and each resin molded body (3) to the adhesive or complementarily. 3f) can be used together, and both side parts 3g and ceiling parts 3h may be press-fitted to the stepped parts 2g and 2f, respectively.

Since the sliding keys 1 of FIGS. 3, 4, and 5 (a), (b), (c), (d), and (e) all have fitting portions with the groove portions 4b as metal molded bodies, The fitting force to the groove part 4b of the sliding key 1 can be improved.

In addition, the sliding key 1 of FIG. 6 may also be a metal molded body in the same manner as the sliding key 1 of FIGS. 7C, 7D, and 7E, and the fitting portion with the groove portion 4b.

The 2nd sliding key which concerns on this invention is demonstrated by FIG. 8 and FIG. 8A is a plan view of the sliding key, FIG. 8B is a front view, FIG. 8C is a bottom view, FIG. 8D is an AA sectional view of FIG. FIG. 8E is a cross-sectional view taken along line BB, and FIG. 8F is a cross-sectional view taken along line CC. 9 shows a perspective view of the sliding key.

The sliding key 1 consists of the metal molding 2 and the resin molding 3, and the resin molding 3 and the metal molding 2 are integrally joined by screws 10, such as a bolt.

The resin molded body 3 is formed with irregularities that can be complementarily fitted into the metal molded body 2, and the resin molded body 3 and the metal molded body 2 are joined by fitting the complementary irregularities. Thereafter, they are joined together by screws 10. By fitting complementary irregularities, the resin molded body 3 and the metal molded body 2 are not separated during the continuously variable transmission operation.

As shown in Fig. 8, the metal molded body 2 has a concave portion 2a at the CC cross section, is formed in an inverted T shape at the BB cross section, and is formed under the sliding key 1, that is, the groove portion 4b ( The press-fit fitting portion into Fig. 13 is constituted (Figs. 8B to 8F). Further, the resin molded body 3 is formed in an H shape so as to form a sliding key 1 having a rectangular cross section, and the sliding key 1 is fitted by fitting complementary irregularities with the metal molded body 2. ), That is, a sliding portion with the inner circumferential groove of the slide cylinder 8a (see FIG. 13) is constituted (FIGS. 8A and 8B).

In addition, the screw 10 does not protrude from each side of the rectangular cross section of the sliding key 1, and if the metal molding 2 and the resin molding 3 can be fixedly attached, the type of screw and the screw The number, screw fixing direction, or the like is not relevant.

A third sliding key according to the present invention will be described with reference to FIGS. 10 and 11. 10 is a perspective view of the sliding key, and FIG. 11 is an exploded perspective view of each component.

The sliding key 1 is composed of the metal molding 2 and the resin moldings 3a and 3b, and the resin moldings 3a and 3b are formed with irregularities that can be complementarily fitted with the metal molding 2, And the complementary irregularities are sandwiched and joined. Thereafter, the resin molded bodies 3a and 3b are formed integrally with the metal molded body 2 by welding each other at the joint surface 1a. In the resin molded body 3a, the welding surface 3c which can mutually weld with "3b" is formed, and the welding surface 3d corresponding also to the resin molded body 3b is formed. By welding the welding surfaces 3c and 3d corresponding to each other, the resin moldings 3a and 3b are firmly bonded at the bonding surface 1a, whereby the metal molded body 2 can be fixedly attached to the resin molding. As a welding method, well-known welding methods, such as high frequency welding, can be employ | adopted.

In addition, the bonding surface of the resin molded body and the metal molded body other than the bonding surface 1a between the resin molded bodies can be bonded to the metal molded body 2 by welding the resin to improve the adhesive strength. In this case, the adhesion strength is improved by coupling the metal molded body 2.

The shapes of the first, second and third sliding keys 1 according to the present invention are press-fitted to the groove portions 4b formed in the outer circumference of the end portion 4a of the rotating shaft, shown in FIGS. 12 and 13 described later. It can be a shape which does not shift | deviate with respect to an axial load. In addition, the part which press-fits to the groove part 4b is the shape 1 in which the most part becomes a metal molded object 2, and the site | part which slides with the inner peripheral groove part of the slide cylinder 8a becomes the resin molded object 3. desirable. The fitting force of the sliding key 1 is improved by making most of the press fitting part into the metal molded body 42, and the sliding property of the slide cylinder 8a and the rotating shaft 4 by making the sliding part into the resin molded body 3 is made. This is improved.

As the metal molded body 2 usable for the first, second and third sliding keys 1 according to the present invention, a machined product, a forged product, a lost wax product, a sintered metal product, a metal injection product, or the like can be used. Among them, lost wax products and sintered metal products are preferred for reasons of strength reliability and cost. Moreover, in the welding type of resin molding, porous bodies, such as a sintered metal article and a metal injection article, are especially preferable from the reasons of weldability at the junction part of a metal body and a resin molded object, manufacturing cost, etc. Moreover, you may use nonferrous metals, such as aluminum and its alloy, as a raw material. Moreover, surface treatment, such as plating, can be performed in order to prevent rust of a surface.

The shape of the metal molded body 2 is preferably a shape in which the resin molded body 3 cannot be separated from the metal molded body 2 during the CVT operation.

The resin composition which forms the resin molding 3 which can be used for the 1st, 2nd and 3rd sliding key 1 which concerns on this invention can be used if it is a resin composition which is excellent in friction and abrasion characteristics, and has high mechanical strength. Although the molding method can employ | adopt the resin composition which can be shape | molded by injection molding, compression molding, transfer molding, etc., the resin composition which can be injection-molded is especially preferable. Moreover, in the welding type of resin molding, since welding strength becomes high by making the resin molding 3a, 3b shown in FIG. 11 into the same resin composition, it is preferable.

As resin components having excellent friction / wear characteristics and high mechanical strength that can be injection molded, polyether ketone resins such as thermoplastic polyimide resins, polyether ether ketone resins and polyether ketone resins, polyacetyl resins, polyamide resins, polyethylene resins, Polyamideimide resin, polyether nitrile resin, aromatic polyester resin, polyphenylene sulfide resin, etc. can be illustrated. This can be used alone or as a polymer alloy or a polymer blend composed of two or more resins.

Among them, a resin containing a thermoplastic polyimide resin and a polyether ketone resin as a main component capable of obtaining a sliding key excellent in mechanical strength and sliding properties is particularly preferred because it can sufficiently satisfy mechanical properties, rigidity, heat resistance and injection molding.

In the thermoplastic polyimide resin, as shown in Chemical Formula 1, an ether bonding portion exhibiting proper melting characteristics by adding energy such as heat while imide groups having excellent thermal characteristics and mechanical strength in the repeating unit of the molecular structure surrounds an aromatic group. Since the imide type resin of the structure which has several is good, and satisfy | fills mechanical property, rigidity, heat resistance, and injection-molding property, the thermoplastic polyimide resin which has two ether bond parts in a repeating unit is preferable.

In Formula 1, X represents a group selected from the group consisting of a direct or hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, and a sulfone group, and R1 to R4 represent hydrogen, a lower alkyl group (preferably And C1-5), lower alkoxy group (preferably C1-5), chlorine or bromine, and may be the same or not the same.Y is an aliphatic group having 2 or more carbon atoms, a cyclic aliphatic group, or a monocyclic aromatic group. , A condensed polycyclic aromatic group, a tetravalent group selected from the group consisting of non-condensed polycyclic aromatic groups interconnected by direct or crosslinking groups.)

As such a thermoplastic polyimide resin, Mitsui Chemical Co., Ltd. brand name AURUM etc. which are all R <1> -R <4> in formula (1) are hydrogen.

The polyether ketone resin is a resin having a repeating unit as shown in the following formula (2), or the repeating unit represented by the following formula (3) together with such a repeating unit to the extent that the original characteristics of the polyether ketone resin is not lost Says Susie.

Commercially available products of such polyether ketone resins include PEEK150P (Biktrax MC, trade name), PEK220G (ICI, trade name), UltrapekA2000 (BASF, trade name) and the like.

The resin compositions constituting the resin molded body 2 include tetrafluoroethylene resin, graphite, molybdenum disulfide, tungsten disulfide, graphite fluoride, boron nitride, silicon nitride, and other solid lubricants, glass fibers, carbon fibers, and whiskers. Various fillers, such as a reinforcing material, calcium carbide, clay, a mica, etc. can be mix | blended.

The resin molded body 1 is molded using an injection molding method.

The pulley unit using the first, second and third sliding keys 1 according to the present invention has a compact, lightweight and low cost continuously variable transmission.

12 shows a pulley unit for a continuously variable transmission employing the sliding key 1. The pulley unit is provided with a fixed pulley 7 on a rotary shaft 4 which is driven by an engine (not shown), and is engaged with the rotary shaft 4 by a sliding key 1 so as to be capable of following rotation, and in the axial direction thereof. The movable pulley 8 is provided in the slide cylinder 8a which slides in the opposite direction, and is provided between the fixed pulley 7 and the fixed pulley 7 and the movable pulley 8 by sliding the slide cylinder 8a. The wound diameter of the wound V-belt 9 is changed, and the transmission ratio is made to change steplessly.

FIG. 13A shows a perspective view of the end 4a of the rotating shaft, and FIG. 13B shows a sectional view when the sliding key is fitted.

As shown in Fig. 13 (a), the rotary shaft 4 has a small diameter end portion 4a formed at one end thereof, and is provided with a sliding key in each of the key grooves 4b provided at four circumferential directions of the outer diameter surface thereof. 1) is fitted.

The slide barrel 8a has a small diameter inner diameter portion 8b formed on the side opposite to the movable pulley 8, and as shown in Fig. 13B, the circumferential direction 4 of the inner diameter surface of the small diameter inner diameter portion 8b. In some places, a key groove 8c into which the sliding key 1 is fitted is provided.

In addition, as shown in FIG. 12, push 6a, 6b press-fits into the inner diameter surface of the movable pulley 8 side, and the inner diameter surface of the spacer ring 6 press-fitted to the end of the small diameter inner diameter part 8b, respectively. It is. Therefore, the slide cylinder 8a is axially rotated in the axial direction of the rotary shaft 4 while the circumferential position is regulated by the respective keyways 8c and the sliding key 1 and the radial position is regulated by the respective pushes 6a and 6b. Slides.

In addition, in this embodiment, although a sliding key was fitted to the key groove of the rotating shaft side, a sliding key can also be fitted to the key groove of the slide cylinder side on the contrary.

In addition, other components except the sliding key of the continuously variable transmission according to the present invention may be conventional components.

In the above-described embodiment, the sliding key is employed in the pulley unit for the continuously variable transmission, but the sliding key according to the present invention can also be employed in a driving force transmission device for moving other pulleys and teeth in the axial direction during rotation.

Embodiments of the second and third sliding keys 1 according to the present invention will be described.

(Example 1)

The metal molded body 2 and the resin molded body 3 were fixedly attached with a screw to produce a sliding key 1 shown in FIG. Since only the resin molded product is injection molded, even if burrs are generated, they can be completely removed before being inserted into the metal molded body. 12. Using the sliding key 1, the continuously variable transmission shown in FIG. 12 was assembled, resulting in sticking or breaking under an operating environment of a temperature of about 120 ° C., a load of about 250 kgf, and a sliding speed of 1.4 mm / sec. There was no. Also, no burr occurred during operation.

On the other hand, although the metal molded body was insert-molded as a comparative example, burrs generate | occur | produced in the boundary part of a metal molded object and a resin molded object. Before attaching to the continuously variable transmission, it was necessary to tumble for a long time to completely remove the burr.

(Example 2)

The metal moldings 2 were formed by sintering, and the resin molded bodies 3a and 3b were formed by injection molding from polyether ether ketone resins, respectively. In addition, since the resin molded objects 3a and 3b were the same shape, they were shape | molded using the same metal mold | die. The resin molded parts 3a and 3b were integrally assembled with the metal molded object 2, and welded using the ultrasonic welding machine (made by Seidenshaden Kogyo Co., Ltd.), and the sliding key 1 shown in FIG. 10 was produced.

Burr does not generate | occur | produce the obtained sliding key 1, and the adhesive strength of the resin molded object and the metal molded object was equal or more compared with the sliding key which insert-molded a metal molded object.

12. Using the sliding key 1, the continuously variable transmission shown in FIG. 12 was assembled, resulting in sticking or breaking under a use environment of a temperature of about 120 ° C., a load of about 250 kgf, and a sliding speed of 1.4 mm / sec. There was no. Also, no burr occurred during operation.

A fourth sliding key according to the present invention will be described with reference to FIG. (A) is a top view of a sliding key, FIG. 14 (b) is a front view, FIG. 14 (c) is a bottom view, and FIG. 14 (d) is a DD sectional view in (a), respectively. do.

The sliding key 1 consists of the metal molding 2 and the resin molding 3, The resin molding 3 is formed by integral formation with the metal molding 2. As shown in FIG.

The shape of the sliding key 1 is shown in FIG. The shape can be press-fit to the groove part 4b formed in the outer periphery of the edge part 4a of a rotating shaft, and is a shape which does not shift with respect to an axial load. In addition, it is preferable that the part which press-fits to the groove part 4b becomes the metal molded object 2, and the site | part which slides with the groove part inside the slide cylinder 8a becomes the resin molded object 3 preferably. The fitting force of the sliding key 1 is improved by making most of the press fitting part into the metal molded object 2, and the sliding property of the slide cylinder 8a and the rotating shaft 4 by making the sliding part into the resin molded object 3 is made. This is improved.

The metal molded body 2 and the resin molded body 3 may use the same material as the first, second and third sliding keys.

The shape of the metal molded body 2 is preferably a shape in which the resin molded body 3 and the metal molded body 2 cannot be separated during operation of the continuously variable transmission when integrally molded. Specifically, as shown in Fig. 14D, a groove or a through hole 2h is formed in the metal molded body 2. Since the resin molded body 3 is filled in this groove or the through hole 2h by the through hole 2h or the like to form a composite of the resin composition and the metal at the time of integral molding, the sliding key 1 of the present invention is made of an adhesive or the like. It becomes a solid integrally molded product without using

Further, the cross-sectional shape of the metal molded body 2 is cross-shaped so that the longitudinal corner portion 3i of the sliding key bottom portion becomes the resin molded body 3, and the corner portion 2i on the bottom side that forms the longitudinal corner portion 3i. ) Is inwardly concave (Fig. 14 (d)).

The inwardly concave corner portion 2i is preferably the size required for resin to flow into the corner portion 3i during injection molding, and does not tilt or slip when the sliding key is pressed into the groove portion 4b of the rotating shaft. It is preferable to have the side portion 2j of the metal molded body of sufficient size. Specifically, the corner portion 2i is preferably sized to include the inclined portion of the corner portion 3i so that the bottom surface portion and the side surface portion of the sliding key 1 can be formed of the resin molded body 3. Although it depends also on the resin molding (3) used, in the case of resin which has a thermoplastic polyimide resin and a polyether ketone resin as a main component, in FIG.14 (d), the bottom length x side length are (5-15). As for the corner part 2i of one side, it is preferable that the hidden part of the bottom surface and the side surface is (0.5-3.0) mm while it is mm * (5-15) mm. In the case where the press-fitting is not required, the longitudinal corner portion 3i of the sliding key bottom portion can be part of the resin molded body 3.

The injection molding method according to the present invention can be obtained by injection filling a resin composition into a mold in which a metal molded body 2 is disposed. Depending on the shape of the metal molded body 2, the number of gates may be plural and a one-point gate system or a multi-point gate system can be adopted. For example, the sliding key shown in FIG. 14 shows an example using a two-point gate method in which two gate traces 11 remain.

Moreover, the sliding key 1 integrally formed is taken out from a metal mold | die by the protrusion pin in the surface on the opposite side to a gate. By arrange | positioning the position of a protrusion pin in the position which becomes a resin part of a bottom surface, since the metal molding 2 and the resin molding 3 are taken out from a metal mold without peeling, productivity improves. Thereby, the protrusion pin trace 12 at the time of injection molding is formed in the resin part of the bottom surface of the sliding key 1.

As the sliding key 1 of the continuously variable transmission shown in Figs. 12 and 13 was assembled using the sliding key 1, it was possible to press-fit the sliding key 1 without causing the goling. In addition, the continuously variable transmission did not cause seizure or breakage under a use environment of a temperature of about 120 ° C., a load of about 250 kgf, and a sliding speed of 1.4 mm / sec.

An example in which the inwardly concave corner portion 2i is formed only on the inclined portion of the longitudinal corner portion 3i of the sliding key bottom portion is shown as a comparative example in FIG. 15. 15A is a plan view of a sliding key, FIG. 15B is a front view, FIG. 15C is a bottom view, and FIG. 15D is an enlarged view of EE in FIG. 15A. Sectional drawing and FIG. 15E show FF enlarged sectional drawing in FIG. 15A, respectively.

If the inwardly concave corner portion 2i is small, the flow of resin is difficult during injection molding, and the entire corner portion of the slippery bottom portion cannot be filled with resin. That is, the part 3j in which resin was filled, and the part 3k in which it was not filled arises (FIG. 15 (b), (c)). As a result, the part in which the corner part of the bottom part is not formed by resin molding arises (FIG. 15 (e)). In the portion 3k not filled with the resin, the corner portion of the metal molded body 2 has an acute angle shape, and a goling phenomenon or the like occurs when press-fitting into the groove portion. Moreover, since the part of the resin molded body 3 formed in the corner | angular part of a slippery bottom part becomes thin, and is not integral, the adhesiveness of the metal molded body 2 and the resin molded body 3 falls.

An example of the structure of the sliding key according to the present invention will be described with reference to Figs. FIG. 16 is a perspective view of a resin molded body fitted to a groove portion recessed in a rotating shaft or a slide cylinder, and FIGS. 17 to 20 are views for explaining a sliding key structure, respectively.

The resin molded body 3 has a groove 3m which can fit into a groove portion recessed in the outer periphery of the rotating shaft or the slide cylinder, and which can fit a sliding key or a projection. Moreover, the shape which cannot move even if it loads in an axial direction after fitting in a groove part is preferable. This shift prevention in the axial direction can be performed in a fitting shape to the groove portion or by using a washer or the like described later.

It is preferable that the upper surface of the resin molded body 3 fitted into the groove portion is convex or concave in an arc shape so as to have an outer circumferential surface of the end portion 4a of the rotating shaft or the same circumferential surface as the inner circumferential surface of the slide cylinder 8a. .

In FIG. 17, (a) is the front view of the state which fitted the resin molded object, (b) is sectional drawing of the state in which the sliding key is fitted to the rotating shaft and the slide cylinder, (c) is the protrusion provided convexly to the slide cylinder. The cross section of the state fitted as a sliding key is shown, respectively.

In the continuously variable transmission shown in FIG. 12, the sliding key structure shown in FIG. 17 is a groove portion recessed in the shape of a long hole in the longitudinal direction of the outer circumference of the end 4a formed on the outer circumference of the rotating shaft 4 ( The groove 3m of the resin molded body 3 is made into a key groove by fitting the resin molded body 3 into 4b) (FIG. 17 (a)). The groove part 4b is formed in at least one place, Preferably it is formed in multiple places at equal intervals in a circumferential direction. Subsequently, the sliding key 1 is fitted with the groove 3m and the key groove 8c formed on the inner circumferential surface of the slide barrel 8a to obtain a sliding key structure in which the rotary shaft 4 and the slide barrel 8a are engaged. It may be (FIG. 17B). In addition, instead of the sliding key 1, the projection 8d provided convexly in the inner peripheral surface of the slide cylinder 8a may be made into the structure of the sliding key obtained by fitting in the groove | channel 3m of the resin molding 3 (FIG. 17). (c)).

The perspective view of the edge part 4a of the sliding key structure shown in FIG. 17 is shown to FIG. 18A, and sectional drawing is shown to FIG. 18B, respectively. In the end portion 4a formed on the outer circumference of the rotating shaft 4, the groove portion 4b is concavely installed in the shape of a long hole in the outer circumferential direction thereof, and the sliding key 1 can be inserted from the end in the same longitudinal direction. An insertion groove 4d having a groove width that is provided is recessed. The resin molded body 3 is fitted into the groove portion 4b, the groove 3m of the resin molded body 3 becomes a key groove, and the sliding key 1 is fitted. The sliding key 1 which can be inserted at the end is used to prevent misalignment in the axial direction using the washer 13.

In FIG. 19, (a) is the front view of the state which fitted the resin molding 3, (b) is sectional drawing of the state in which the sliding key is fitted to the rotating shaft and the slide cylinder, (c) is convex to the rotating shaft. The cross section of the state in which the installed processus | protrusion was fitted as a sliding key is shown, respectively. 20 is a partial perspective view of FIG. 19.

The sliding key structure shown in FIG. 19 fits the resin molded object 3 into the groove part 8c recessed in the inner peripheral surface of the slide cylinder 8a, and makes the groove 3m of the resin molded object 3 the key groove (FIG. (A)) of 19. The groove part 8c is formed in at least one place, Preferably it is formed in multiple places at equal intervals in the direction of inner circumference. Then, the sliding key 1 is fitted to the groove portion 4b recessed in the groove 3m and the end portion 4a of the rotary shaft 4, and the sliding key 4 is engaged with the rotary shaft 4 and the slide cylinder 8a. A structure is obtained (FIG. 19B). Instead of the sliding key 1, the projection 4d provided convexly at the end 4a of the rotating shaft may have a sliding structure obtained by being fitted into the groove 3m of the resin molded body 3 (Fig. 19 (c) )).

The perspective view of the groove part 8c in the sliding key structure shown in FIG. 19 is shown to FIG. 20 (a), and sectional drawing is shown to FIG. 20 (b), respectively. The groove 8c is recessed in the shape of a long hole in the longitudinal direction of the inner circumferential surface of the slide cylinder 8a. The resin molded body 3 is fitted into the groove 8c, and the groove 3m of the resin molded body 3 becomes a key groove. The sliding key fitted to the key groove is used to prevent displacement in the axial direction by using the washer 13.

In the sliding key structure shown in Fig. 17, the sliding portion with the sliding key 1 or the inner circumferential protrusion 8d becomes the groove 3m of the resin molded body 3, so that the sliding in the axial direction is improved. By making the sliding key 1 into a metal molded body, the fitting force of a sliding key improves.

Similarly, in the sliding key structure shown in Fig. 19, the sliding portion 1 and the projection 4d become the groove 3m of the resin molded part 3, so that the sliding in the axial direction is improved. Moreover, the fitting force of a sliding key improves by making the sliding key 1 into a metal molded object.

The sliding key 1 can use machined products, forged products, lost wax products, sintered metal products, metal injection products and the like. Of these, lost wax products are preferred for reasons of strength reliability, cost, and the like. Moreover, in order to prevent surface rust, surface treatment, such as plating, can be performed.

Moreover, the sliding key 1 can also use the integral molded article of a resin molded object and a metal body.

The resin composition for forming the resin molded body 3 may be injection molding, compression molding, transfer molding, or the like as the molding method. Among these, the resin composition which can be injection-molded is preferable. This is because the groove to be fitted can be easily formed even in a complicated shape. The resin composition which can be injection-molded can use what was used for the 1st sliding key mentioned above. The continuously variable transmission can be the continuously variable transmission shown in FIG.

The sliding key structure according to the present invention will be described by Examples 3 to 6, Comparative Example 2 and Comparative Example 3.

(Examples 3 to 6 and Comparative Examples 2 to 3)

As a resin composition, the surface of a machined product was plated with a thermoplastic polyimide resin composition (Bearer PI5010: NTN Precision Resin brand name) and a polyether ketone resin composition (Barrier PK5060: NTN Fine Resin brand name) as a sliding key. The thing of the shape of the sliding key 1 shown in 18 was prepared, respectively.

Injection molding conditions (thermoplastic polyimide resin composition: pressure; 255 MPa, temperature; 410 ° C., polyether ketone resin composition: pressure: 255 MPa, temperature; 380 ° C.) )

In addition, Example 3 and 4 employ | adopt the structure of FIG. 17B, Example 5 and 6 employ | adopt the structure of FIG. 19B, respectively, and this injection molded object is the edge part 4a of the shaft 4, respectively. Both ends in the axial direction have the same shape as the grooves 4b or 8c so as to fit into the long circular grooves 4b provided in the grooves or the grooves 8c recessed in the slide cylinder, and are set so as not to be displaced with respect to the axial load. did.

Evaluation of the obtained sliding key structure was repeated and carried out by friction coefficient measurement by a shear fatigue test and a friction test.

Repeated shear fatigue test will be described with reference to FIG. 21 shows a repeated shear fatigue tester.

The resin molded body 3 is fitted into the groove formed in the shaft 14, and the sliding key 1 is fitted into the housing 15 in which the metal molded body fitting groove is formed. Fit the inner circumference of (15). At this time, the fitting of the groove of the housing 15 and the sliding key 1 is fitted by fitting. The hydraulic vibration device 16 and the load cell 17 for controlling by a constant load are attached to the housing 15, and the sliding key 1 is repeatedly subjected to sliding movement about the central axis 14a of the shaft, thereby providing repeated fatigue to the sliding key 1. do. At this time, the test conditions were carried out at an ambient temperature of 120 ° C., an excitation speed of 10 Hz, and a load torque of 50 N · m, and the test was performed until the amount of displacement of the resin molded body 3 became 0.1 mm.

21 shows the method of FIG. 17 (b), and the test conditions of the method of FIG. 19 (b) are identical except that the fitting portions of the resin molded body 3 and the sliding key 1 are different.

The friction test will be described with reference to FIG. 22 shows a friction tester.

The test piece 20 in which the sliding key 1 was fitted into the groove 3m of the resin molded body 3 is fixed to the base 19 loaded with an air cylinder (not shown). A load cell 17 measuring the drive device 18 and sliding resistance on a table 22 having the counterpart 21 using a plate material nickel-phosphorized with S45C for the counterpart 21 of the test piece 20. ) And reciprocate the table 22 by 30 mm stroke. Specific test conditions were an ambient temperature of 120 ° C., a load load of 50 MPa, and a reciprocating speed of 1.5 mm / sec. Moreover, the evaluation result using a plate-shaped thing is shown in following Table 1 as the test piece 20 in this test. In addition, Comparative Example 2 and Comparative Example 3 are sliding keys using the thermoplastic polyimide resin composition alone and the polyether ketone resin composition alone.

Sliding structure Repeated shear fatigue test load torque, 50N-m Abrasion test (friction test) surface pressure, 47 MPa Shape resin Example 3 Figure 17 (b) PI More than 200,000 0.05-0.08 4 PEEK More than 350,000 0.2 to 0.4 5 (B) PI of FIG. 19 More than 150,000 0.05-0.08 6 PEEK More than 250,000 0.2 to 0.8 Comparative Example 2 PI 70,000 or less 0.05-0.08 3 PEEK 50,000 or less 0.2 to 0.4

Note) PI: Thermoplastic polyimide resin composition

PEEK: polyether ether ketone resin composition

As shown in Table 1, the sliding key structures of Examples 3 to 6 exhibited about three times or more repeated shear fatigue characteristics compared to the sliding keys of the resin composition alone, and the friction coefficients were equivalent.

Moreover, when the continuously variable transmission shown in FIG. 5 was assembled using the sliding-key structure of Example 3 and Example 5, it adhered in the use environment of the temperature of about 120 degreeC, the load of about 250 kgf, and the sliding speed of 1.4 mm / sec. Did not cause breakage.

The first sliding key according to the present invention is a composite body in which a metal molded body and a resin molded body are integrally bonded to each other, and at least the slidable parts of both sides are formed of a resin molded body so that stable operation is possible even in a high temperature and high load use environment. It can be secured, inexpensive and inexpensive to manufacture, and undamaged metal molded parts can be reused in management.

In the second and third sliding keys according to the present invention, since the metal molded body and the resin molded body are joined by screws or the resin molded parts are welded together, burrs are not generated during use, and a high-temperature, high-load operating environment is used. It does not cause sticking or damage even when used under Moreover, manufacturing cost can also be suppressed and quality is also stable.

In addition, since the metal molded body and the resin molded body are joined by irregularities to be complementarily fitted together, they have excellent workability during assembly.

The fourth sliding key according to the present invention is a composite integrally molded product of a metal molded body and a resin molded body, and the groove part is formed in the resin molded body in the longitudinal corner of the sliding key bottom part to be fitted into the groove provided in the outer peripheral portion of the rotating shaft. It can be press-fitted or fitted without goling when mounted on Moreover, since the chamfering process of a post process is unnecessary, productivity improves. Moreover, since rust does not generate | occur | produce, it is excellent in durability.

In addition, since the resin molded body is formed of a resin composition which can be injection molded, the composite molded body can be easily formed with a complex metal molded body. As a result, the sliding key which is excellent in a mechanical characteristic and low cost can be obtained.

Moreover, since the protrusion pin trace at the time of injection molding is formed in the resin part of the bottom surface which fits into the groove part provided in the rotating shaft, even if it is a complex integral molded article of a complicated shape, the adhesiveness of a resin molded object and a metal molded object is excellent.

The sliding key structure of the present invention does not cause sticking or damage even when used in a high-temperature, high-load operating environment because the sliding portion of the sliding key on the inner surface of the groove portion recessed to the rotating shaft or the slide barrel engaged with each other is made of a resin molded body. .

Moreover, since a resin molded object and a sliding key are separate, a manufacturing process can be shortened.

Moreover, since a resin molded object consists of resin compositions which can be injection molded, even a complicated shape can be molded.

Moreover, since the projection provided convexly in the slide cylinder or the rotating shaft is made into the sliding key, the structure becomes simpler.

As a result, a sliding key structure having excellent mechanical properties and low cost can be obtained.

The pulley unit of the present invention allows the slide barrel provided with the movable pulley to be engaged with the rotating shaft provided with the fixed pulley by using the sliding key, so that it can be stably operated even under high load using conditions without using an expensive ball spline structure. Can be.

In addition, it is easy to attach, a simple structure is possible, and a low cost continuously variable transmission can be obtained at a small size and light weight.

Claims (18)

In the sliding key which is slidable in the axial direction of the rotating shaft and which can be rotated to follow, the sliding key provided on both sides of the sliding shaft or the sliding passage with the slide shaft, The sliding key is a composite in which a metal molded body and a resin molded body are separately joined together, and at least the sliding parts on both sides are formed of the resin molded body. The method of claim 1, A sliding key, wherein the metal molded body and the resin molded body are integrally bonded to each other via an adhesive at a joint portion. The method of claim 2, A sliding key, characterized in that the adhesive is an epoxy adhesive. The method of claim 2, A sliding key characterized in that the adhesive melts a film-shaped molten fluorine resin. The method of claim 1, And the metal molded body and the resin molded body are integrally bonded by press-fitting the resin molded body having a portion complementarily fitted to the recess formed in the metal molded body. The method of claim 1, And the metal molded body and the resin molded body are integrally joined to both sides of the metal molded body by the resin molded body in which the sliding parts on both sides are integrally joined. The method of claim 1, A sliding key, wherein the metal molded body and the resin molded body are integrally joined by screwing. The method of claim 1, A sliding key, wherein the metal molded body and the resin molded body are welded together so as to sandwich the metal molded body with a plurality of the resin molded bodies. The method according to any one of claims 1 to 8, A sliding key, wherein the metal molded body and the resin molded body are joined together by irregularities to be complementarily fitted. In the sliding key which is slidable in the axial direction of the rotating shaft and engages the slide cylinder so as to be able to follow the rotation, The sliding key is a composite integrally molded product of a metal molded body and a resin molded body, and a corner portion of the sliding key bottom portion fitted to the groove portion provided concave in the rotary shaft or the slide barrel is formed of the resin molded body in the longitudinal direction. Sliding. The method according to any one of claims 1 to 10, The resin molding is a sliding key, characterized in that made of a resin composition capable of injection molding. The method of claim 11, The sliding key characterized in that the protrusion pin trace during injection molding is formed in the resin portion of the bottom surface. In the sliding key structure, which is slidable in the axial direction of the rotating shaft, and which engages the slide cylinder with the rotating shaft so as to follow the rotating direction, Sliding key structure, characterized in that the sliding key sliding portion of the inner surface of the groove portion recessed in the rotating shaft or the slide barrel made of a resin molded body. The method of claim 13, The resin molded body is a molded product of a resin composition capable of injection molding. The method according to claim 13 or 14, A sliding key fitted to the groove is a sliding key structure, characterized in that fit to the groove portion recessed in the mating slide cylinder or the rotating shaft to be engaged. The method of claim 14, The sliding key fitted to the groove portion is a sliding key structure, characterized in that the projection convexly installed on the slide cylinder or the rotating shaft. A plurality of key grooves are formed at appropriate intervals in the circumferential direction of the outer diameter surface of the rotary shaft, and a plurality of key grooves in accordance with the interval of the key grooves of the rotary shaft in the circumferential direction of the inner diameter surface of the slide cylinder sliding in the axial direction of the rotary shaft. Is formed, and the slide cylinder is rotatably engaged with the rotary shaft by a sliding key fitted to the plurality of key grooves of the rotary shaft or the slide cylinder, or by a sliding key structure that engages the rotary shaft and the slide cylinder. In the pulley unit having a fixed pulley is provided on the rotating shaft, the movable pulley is provided in the slide cylinder facing the fixed pulley, The said sliding key was made into the sliding key in any one of Claims 1-12, or the sliding key structure in any one of Claims 13-16. The pulley unit characterized by the above-mentioned. The method of claim 17, The pulley unit, characterized in that for the continuously variable transmission.