Chain guide

Abstract

To provide a light-weight chain guide which has a simple configuration, can reduce the manufacturing cost, and has abrasion resistance while securing rigidity as a chain guide.SOLUTION: A chain guide includes a body made of thermoplastic resin or thermoplastic elastomer. The body has a sliding surface on which a chain slides, and a coating film by a coating material is formed at least on a part of the sliding surface, and thickness of the coating film is at least 5 μm or more.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a chain guide having a main body made of a thermoplastic resin or a thermoplastic elastomer. [Background technology]

[0002] Conventionally, there has been known a chain guide that includes a base material made of a metal or resin material, and a shoe material that can be assembled with the base material and has a sliding surface that comes into sliding contact with the chain, and in which the sliding surface is made of a material that has excellent wear resistance and low friction characteristics in order to reduce the frictional force generated when sliding with the chain while maintaining wear resistance (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2005-112871 Summary of the Invention [Problem to be solved by the invention]

[0004] The chain guide known from Patent Document 1 and elsewhere is a chain guide that is composed of a base material 1 made of a metal material and a sliding resin material 2 that is formed separately on the surface of the base material 1 and forms a sliding surface with the chain. The sliding resin material 2 is composed of a resin matrix 20 made of PA66 and a resin coating layer 21 that is integrally formed on the resin matrix 20 and is made of a sliding resin in which solid lubricant and hard components are dispersed. However, in the chain guide known from Patent Document 1 and the like, the base material 1 is made of a metal material, which ensures the rigidity of the chain guide as a whole, but on the other hand, the mass of the entire chain guide increases, which could increase the mass of the entire engine, and there is also a risk of increased costs due to the metal processing required for the base material 1. Furthermore, the base material 1 and the sliding resin material 2 are separate bodies, and if it is necessary to assemble the base material 1 and the sliding resin material 2, there is a risk that production costs and production efficiency will decrease. Furthermore, when assembling the base material 1 and the sliding resin material 2, it is necessary to consider the shape of the assembly part to prevent them from falling off after assembly, and the shape of the joints between the parts, which could extend the design period.

[0005] It is also possible to mold the base material 1 and the sliding resin material 2 as a single unit using the same material, but if the base material 1 were made from PA66, which also constitutes the resin matrix 20, the rigidity and fatigue characteristics of the chain guide as a whole would be insufficient, and when the chain slides against the sliding surface, the contact area with the chain would increase, which could result in increased friction loss.

[0006] The present invention aims to solve these problems and provide a chain guide that has a simple configuration, reduces production costs, and is lightweight and wear-resistant while maintaining the rigidity of the chain guide. [Means for solving the problem]

[0007] The chain guide of the present invention is a chain guide having a main body made of a thermoplastic resin or a thermoplastic elastomer, the main body having a sliding surface on which the chain slides, and at least a portion of the sliding surface being coated with a coating material, the thickness of the coating being at least 5 μm or more, thereby solving the above-mentioned problems. [Effects of the Invention]

[0008] According to the invention of claim 1, the chain guide has a main body made of thermoplastic resin or thermoplastic elastomer, and the main body has a sliding surface on which the chain slides, so there is no need to assemble a separate sliding part to the main body, which reduces production costs and improves production efficiency. Furthermore, at least a portion of the sliding surface is coated with a coating material, and the thickness of the coating is at least 5 μm or more, so that minute irregularities transferred from the mold to the surface of the main body are smoothed by the coating, improving the surface roughness of the sliding surface. Furthermore, by making the coating film a different color from the main body, it is possible to tell from the outside whether or not a coating film has been formed.

[0009] According to the configuration of claim 2, the thermoplastic resin or thermoplastic elastomer contains a filler, which improves the rigidity of the main body, and the coating is formed on a surface that has not been pre-treated, which makes surface treatment such as blasting unnecessary for the surface on which the coating is formed.In addition, the coating can be formed on a rough surface that has not been pre-treated, which strengthens the adhesion of the coating and allows the formation of a coating that does not deteriorate the surface properties. Furthermore, even when a chain slides against a sliding surface on which a coating is formed and the sliding surface is pressed, the sharp protrusions caused by the filler do not reach the surface of the coating, thereby reducing the coefficient of friction and wear resistance when the chain slides against the sliding surface on which a coating is formed, and also reducing damage to the chain.

[0010] According to the configuration of claim 3, the filler particles protrude from the surface of the sliding surface before the coating is formed, and the arithmetic mean roughness Ra is 0.2 or more, so that the anchoring effect of the protruding filler particles and the coating material can further strengthen the adhesive strength of the coating.

[0011] According to the configuration of claim 4, the filler is one or more types selected from the group consisting of glass fiber, mineral, aramid fiber, carbon fiber, and cellulose nanofiber, so that an appropriate material can be selected depending on the usage environment of the chain guide, the material of the chain, etc.

[0012] According to the configuration of claim 5, the coating is formed by stacking a plurality of coating layers, so that the thickness of the coating after formation can be adjusted as desired.

[0013] According to the configuration of claim 6, the coating material comprises a solid lubricant, a binder, and a solvent, and the binder is a thermosetting resin whose surface hardness when hardened is higher than that of the resin material of the main body, so that the coating has high fluidity when applied, and can form a smooth and uniform coating in which the solid lubricant is evenly dispersed.

[0014] According to the seventh aspect of the present invention, the main body has a mounting hole and is supported so as to be swingable relative to an object to which it is attached, thereby allowing the chain guide to be used as a lever.

[0015] According to the configuration of claim 8, the main body has a mounting hole and is fixedly supported on an object to which it is attached, so that the chain guide can be used as a fixed guide.

[0016] According to the configuration of claim 9, the thermoplastic resin is one or more selected from the group consisting of polyamide, polybutylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyether ether ketone, so that an appropriate material can be selected depending on the usage environment of the chain guide, the material of the chain, etc. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view of a chain guide 100 according to an embodiment of the present invention. [Figure 2] 1 is a side view of a chain guide 100 according to an embodiment of the present invention. [Figure 3] 3 is a cross-sectional view of the chain guide 100 according to the embodiment of the present invention taken along the line AA in FIG. 2 before sliding with the chain. [Figure 4] 3 is a cross-sectional view of the chain guide 100 according to the embodiment of the present invention taken along the line AA in FIG. 2 after sliding with the chain. [Figure 5] FIG. 2 is a graph showing the results of measuring the surface friction coefficient of an embodiment of the present invention and a reference product. [Figure 6] FIG. 2 is a graph showing the results of measuring the surface roughness of the sliding surface of Reference Product 1 of the present invention. [Figure 7] FIG. 2 is a graph showing the results of measuring the surface roughness of the coating surface of Example 1 of the present invention. [Figure 8] FIG. 1 shows the results of measuring the surface roughness of the sliding surface of Reference Product 1 of the present invention after sliding with a chain. [Figure 9] FIG. 1 shows the results of measuring the surface roughness of the coating surface of Example 1 of the present invention after sliding against a chain. DETAILED DESCRIPTION OF THE INVENTION

[0018] A chain guide 100 according to an embodiment of the present invention will be described below with reference to the drawings.

[0019] As shown in Figures 1 and 2, the chain guide 100 according to the embodiment of the present invention has a main body 110, a sliding surface 111 on which the chain CH slides, a coating 112 made of a coating material, and a mounting hole 113.

[0020] The main body 110 is made of polyamide 66 resin, which is a thermoplastic resin, and in this embodiment, contains glass fiber as a filler throughout. Furthermore, the main body 110 is molded by injection molding or the like, and the blending ratio of the glass fibers is not particularly limited, and may be any known ratio. The main body 110 is preferably made of a thermoplastic resin or a thermoplastic elastomer, and the thermoplastic resin is preferably polyamide, or one or more of polybutylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyether ether ketone. In addition, fillers other than glass fiber can be used as fillers contained in the main body 110, and it is preferable to use one or more of glass fiber, mineral, aramid fiber, carbon fiber, and cellulose nanofiber. Furthermore, the main body 110 can be made of a resin material that does not contain fillers, making it possible to provide a chain guide with excellent rigidity and fatigue properties. Furthermore, the main body 110 may contain additives such as molybdenum disulfide or PTFE, making it possible to provide a chain guide with excellent sliding characteristics.

[0021] The sliding surface 111 guides the chain CH in sliding motion, and is formed on the outer surface side of the main body 110 over the entire surface in the running direction of the chain CH. Furthermore, the sliding surface 111 is formed integrally with the main body 110, and there is no need to assemble a separate sliding component having a sliding surface to the main body 110. This eliminates the need for materials, molds, and molding machines for forming sliding components, thereby reducing production costs. Furthermore, since the process of assembling the main body 110 and the sliding components is not required, production efficiency is improved and labor costs associated with the assembly can be reduced.

[0022] In this embodiment, the sliding surface 111 has not been subjected to surface treatment such as blasting, and before the coating 112 is formed, the glass fibers serving as filler remain protruding from the surface of the sliding surface 111, and the arithmetic mean roughness of the surface of the sliding surface 111 is Ra 0.2 or more. As a result, even without performing a surface treatment on sliding surface 111, it is possible to form a strongly adhered coating 112 due to the anchor effect between the glass fibers protruding from the surface of sliding surface 111 and the coating material.

[0023] In this embodiment, the coating film 112 made of the coating material is formed over the entire surface of the sliding surface 111 . As a result, when the chain CH slides against the sliding surface 111, the chain CH slides on the coating surface 112b on the coating 112, so it is no longer dependent on the sliding characteristics of the main body 110, and the main body 110 can be molded from a highly rigid material. When forming the coating 112 on the sliding surface 111, there are no particular limitations on the shape of the sliding surface 111, such as the size, number, and length of the arcs that make up the sliding surface 111.

[0024] By stacking two or more coating layers in the coating 112, the surface hardness of the coating 112 can be further increased, and the wear resistance can be improved. In this embodiment, the coating 112 is formed by stacking two 5 μm coating layers, and has a total thickness of 10 μm.

[0025] On the other hand, if the coating 112 is formed to a thickness of at least 5 μm, it is sufficient to function as a coating layer, and it may be formed as only one layer. In addition, one or more layers of coating 112 may be formed on only a portion of sliding surface 111, and the thickness of the coating layer may vary depending on the location on sliding surface 111, in which case the amount of coating material used to form coating 112 can be reduced.

[0026] The coating material forming the film 112 includes a solid lubricant, a binder, and a solvent. The solid lubricant provides lubricity to the coating 112 and may be, for example, a mixture of molybdenum disulfide and graphite. The coating material can be applied to the surface of the main body 110 by a method such as spray painting, and since the coating material contains a solvent, the fluidity of the coating material is improved, allowing for the formation of a smooth and uniform coating 112, and after the coating material hardens, the coating 112 can have the solid lubricant evenly dispersed therein. This is particularly effective when the sliding speed between the chain CH and the sliding surface 111 is low and the contact load is high in an environment lubricated with engine oil or the like.

[0027] The binder is a thermosetting resin whose surface hardness when the coating material hardens is higher than that of the resin material of the main body, which improves the wear resistance of sliding surface 111 and also prevents sharp protrusions caused by the filler from being generated on coating surface 112b when chain CH slides against coating surface 112b and sliding surface 111 is pressed, thereby reducing the coefficient of friction and wear resistance when chain CH slides against the sliding surface, and reducing damage to chain CH. As the binder, for example, polyamide-imide resin, epoxy resin, or the like is preferable.

[0028] The mounting hole 113 has a through-hole and is configured so that it can be mounted to a mounting object by inserting a bolt or the like therethrough. In this embodiment, as shown in Figures 1 and 2, the chain guide 100 has a first mounting shaft hole 113-1, a second mounting shaft hole 113-2, and a third mounting shaft hole 113-3, and has a through hole in a direction parallel to the sliding surface 111, i.e., in the thickness direction of the main body portion 110. In addition, the first mounting shaft hole 113-1 is provided on one end side of the main body portion 110, the third mounting shaft hole 113-3 is provided on the other end side of the main body portion 110, and the second mounting shaft hole 113-2 is provided between the first mounting shaft hole 113-1 and the third mounting shaft hole 113-3.

[0029] The chain guide 100 can be used as a fixed guide by inserting a bolt or the like into the through-hole of the mounting hole 113 and fixing it to an object to be mounted.

[0030] Furthermore, by supporting the chain guide 100 so that it can swing relative to a fixed object, the chain guide 100 can be used as a swing lever. At this time, the main body 110 may be provided with an abutment portion against which a pressing member such as a chain tensioner abuts. Also, a boss may be formed on the outer periphery of any of the mounting holes 113, and a biasing member such as a coil may be loosely fitted into the boss.

[0031] Next, the operation of the coating 112 in the chain guide 100 according to the embodiment of the present invention to prevent the generation of sharp protrusions due to fillers when the chain CH slides will be described with reference to FIGS. In addition, in FIGS. 3 and 4, the thickness of the coating 112 is exaggerated. First, as shown in FIG. 3, the chain CH is in contact with the coating surface 112b of the coating 112 formed on the sliding surface 111 of the chain guide 100, and the chain CH and the coating surface 112b are not yet in sliding contact with each other. Then, as shown in FIG. 4, when the chain CH and the coating surface 112b start to slide from that state, the coating 112 receives an external force from the chain CH.

[0032] At this time, the coating 112, which is made up of two coating layers in this embodiment, both receive an external force from the chain CH, and thus press the main body 110 down. Here, the binder contained in the coating 112 is a thermosetting resin whose surface hardness when hardened is higher than that of the resin material of the main body part, so even if an external force is applied from the chain CH, the coating 112 itself is not compressed, but the main body part 110, which has a lower surface hardness, is compressed. As a result, the coating 112 on the sliding surface 111 does not wear or peel off, and the surface quality can be maintained in a good state. Furthermore, even if the main body 110 is compressed, the coating 112 prevents the glass fibers contained as filler in the main body 110 from penetrating through the coating 112 to the outside of the coating surface 112b, and sharp protrusions caused by the filler do not occur on the coating surface 112b.

[0033] Next, the measurement of the friction coefficient and the surface roughness performed to examine the characteristics of the chain guide of the present invention will be described.

[0034] A chain guide for wear testing according to the present invention (hereinafter referred to as "Example 1") was produced according to the configuration shown in FIGS. The main body of Example 1 is made of polyamide 66 resin, contains glass fiber as a filler, and has one layer of coating material formed on the main body. The coating of Example 1 contained a mixture of molybdenum disulfide and graphite as a solid lubricant and polyamideimide resin as a binder, and was adjusted to a thickness of 5 μm. In addition, a chain guide (hereinafter referred to as "Example 2") was produced that had the same configuration as Example 1 except that the main body did not contain glass fiber as a filler. In addition, a chain guide (hereinafter referred to as "Example 3") was produced that had the same configuration as Example 1, except that the coating material was applied twice to form a film with a thickness of 10 μm. In addition, a chain guide (hereinafter referred to as "reference product 1") was produced that had the same configuration as example product 1 except that it did not have a coating film made of a coating material. In addition, a chain guide (hereinafter referred to as "reference product 2") was produced that had the same configuration as example product 2, except that it did not have a coating film made of a coating material.

[0035] The coefficient of friction of the coating surface or sliding surface of each of the Example 1 and Example 2 and Reference 1 and Reference 2 prepared above was measured and the results are shown in FIG. In addition, the results of measuring the surface roughness of the sliding surface of Reference Sample 1 in the direction perpendicular to the chain running direction are shown in Figure 6, and the results of measuring the surface roughness of the coating surface of Implementation Sample 1 in the direction perpendicular to the chain running direction are shown in Figure 7. As is clear from the results shown in Figure 5, it was confirmed that the coefficient of friction of Example 1 and Example 2 can be significantly reduced compared to Reference 1 and Reference 2, which do not have a coating film made of a coating material. In particular, it was confirmed that the coefficient of friction of Example Product 1 could be reduced by approximately 35% compared to Reference Product 1. Furthermore, as is clear from the results shown in Figures 6 and 7, it was confirmed that the surface properties of Example 1 and Example 2 can be made better than those of Reference 1 and Reference 2, which do not have a coating film made of a coating material.

[0036] Next, the chain was slid against the coating surface of Example 1 and the sliding surface of Reference 1 in the chain running direction at a constant speed for a certain period of time, and the surface roughness at each sliding point after sliding was measured. Figure 8 shows the results of measuring the surface roughness of the reference sample 1 in the direction perpendicular to the chain running direction at the sliding point after sliding, and Figure 9 shows the results of measuring the surface roughness of the working sample 1 in the direction perpendicular to the chain running direction at the sliding point after sliding. As is clear from the results shown in Figures 8 and 9, compared to Reference Product 1, which does not have a coating made from a coating material, even after sliding with the chain, no sharp protrusions due to the filler contained in the main body were generated on the sliding points of the coating surface, and it was confirmed that good surface properties were maintained. On the other hand, after sliding against the chain, Reference Product 1 had sharp protrusions at the sliding points of the sliding surface due to the filler contained in the main body, resulting in poor surface quality and significant wear on the main body.

[0037] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the present invention as set forth in the claims. The chain guide of the present invention can be adapted to various chain layouts, and in addition to the above-described embodiment, the shape and size of the sliding surface, the position where the coating is formed, and the number of layers formed can be freely changed. In the above-described embodiment, the sliding surface 111 may be formed on only a portion of the outer surface of the main body 110 in the running direction of the chain CH. Furthermore, the coating 112 may be formed not only on the sliding surface 111 but also on the entire body 110 . Furthermore, the position, number, size, orientation, etc. of the mounting holes 113 can be changed depending on the constraints of the mounting object, as long as the chain guide 100 can be fixed to the mounting object. [Explanation of symbols]

[0038] 100 ··· Chain guide 110 Main body 111 ··· Sliding surface 112 ... coating 112b... Coating surface 113 Mounting hole 113-1 First mounting hole 113-2 Second mounting shaft hole 113-3 Third mounting hole CH Chain

Claims

1. A chain guide having a main body made of a thermoplastic resin or a thermoplastic elastomer, The main body has a sliding surface on which the chain slides, At least a part of the sliding surface is coated with a coating material, The chain guide is characterized in that the coating has a thickness of at least 5 μm.

2. the thermoplastic resin or the thermoplastic elastomer contains a filler, 2. The chain guide according to claim 1, wherein the coating is formed on a surface of the sliding surface that has not been pretreated.

3. 2. The chain guide according to claim 1, wherein the surface of the sliding surface has the filler protruding therefrom and has an arithmetic mean roughness Ra of 0.2 or more before the coating is formed.

4. 3. The chain guide according to claim 2, wherein the filler is one or more selected from the group consisting of glass fiber, mineral, aramid fiber, carbon fiber, and cellulose nanofiber.

5. 2. The chain guide according to claim 1, wherein the coating is formed by stacking a plurality of coating layers.

6. the coating material includes a solid lubricant, a binder, and a solvent; 2. The chain guide according to claim 1, wherein the binder is a thermosetting resin having a surface hardness when hardened that is higher than that of the resin material of the main body.

7. 2. The chain guide according to claim 1, wherein the main body has a mounting hole and is supported so as to be swingable relative to an object to which it is attached.

8. 2. The chain guide according to claim 1, wherein the main body has a mounting hole and is fixed to and supported by an object to which it is attached.

9. 2. The chain guide according to claim 1, wherein the thermoplastic resin is one or more selected from the group consisting of polyamide, polybutylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyether ether ketone.

Images