阅读说明：本技术 一种新型的静音链及其装配方法 (Novel silent chain and assembling method thereof ) 是由 卢旭东 邢建恒 冯海波 王洪军 汪恭兵 武道 宣成 于 2020-05-14 设计创作，主要内容包括：本发明公开了一种新型的静音链及其装配方法,其技术方案：由工作链板、连接工作链板的销轴和导板组成,所述销轴插入工作链板中,且与导板过盈配合,所述工作链板和导板之间有侧向间隙,工作链板由一对销孔、一对齿和一个齿顶组成,销孔由多段圆弧构成不规则的圆形结构,将工作链板、连接工作链板的销轴和导板装配成链条；预拉力为链条破断载荷的60％-90％,预拉保持时间0-120秒；本发明工作链板能够在不降低链板强度的前提下,通过减小工作链板和销轴的配合间隙,增加铰链接触面积,有效降低铰链接触应力,从而获得最佳的耐磨性能。设计增加储油空间,提升静音链的生产效率,能有效提升链传动系统的使用寿命。(The invention discloses a novel silent chain and an assembly method thereof, and the technical scheme is as follows: the chain consists of a working chain plate, a pin shaft connected with the working chain plate and a guide plate, wherein the pin shaft is inserted into the working chain plate and is in interference fit with the guide plate; the pretension force is 60-90% of the breaking load of the chain, and the pretension holding time is 0-120 seconds; the working chain plate can increase the contact area of the hinge and effectively reduce the contact stress of the hinge by reducing the fit clearance between the working chain plate and the pin shaft on the premise of not reducing the strength of the chain plate, thereby obtaining the best wear resistance. The design increases the oil storage space, promotes the production efficiency of silence chain, can effectively promote chain drive system's life.)

1. The utility model provides a novel silence chain comprises the round pin axle and the baffle of work link joint, connection work link joint, its characterized in that: the pin shaft is inserted into the working chain plate and is in interference fit with the guide plate, and a lateral clearance is reserved between the working chain plate and the guide plate.

2. A novel silent chain as claimed in claim 1, wherein: the working chain plate consists of a pair of pin holes, a pair of teeth and a tooth top, the pin holes are of irregular circular structures formed by multiple sections of circular arcs, and the pin shafts are inserted into the circular pin holes.

3. A novel silent chain as claimed in claim 2, wherein: the pin hole is composed of an engaged working arc AB section, a transition arc BC section, a transition arc CD section, a transition arc EF section, a transition arc FA section and an assembly oil storage arc DE section which are of a certain length.

4. A novel silent chain as claimed in claim 3, wherein: the arc curvature centers O1 and O1' of the pin shaft are the pitch centers of the chain, and the curvature center O2 of the meshing working arc AB section and the curvature center O3 of the assembly oil storage arc DE section of the pin hole are on the same straight line with the pitch center of the chain.

5. A novel silent chain, according to claim 3 or 4, characterized in that: the radius of curvature R2 of the engagement working arc AB section of the pin hole is greater than or equal to the radius of curvature R1 of the arc of the pin inserted into the hole.

6. A novel silent chain as claimed in claim 5, wherein: the curvature radius R3 of the DE section of the oil storage arc for assembling the pin hole is larger than the curvature radius R2 of the AB section of the engaged working arc.

7. A novel silent chain assembling method is characterized by comprising the following steps:

s1, assembling the working chain plate 2, the pin shaft 3 connected with the working chain plate and the guide plate 4 into a chain;

s2, pre-tensioning is needed, the pre-tensioning force is 60% -90% of the broken load of the chain, and the pre-tensioning holding time is 0-120 seconds;

s3, after pre-tensioning, the arc at one side of the pin shaft 3 is tightly attached to the side of the engaging working arc AB section of the working chain plate 2, and a gap is formed between the assembling oil storage arc DE and the arc at the other side of the pin shaft.

8. The novel silent chain assembly method of claim 7, wherein: the size of a gap between the assembling oil storage arc DE and the arc on the other side of the pin shaft is 1% -5% of the chain pitch, and lubricating oil is filled in the gap.

Technical Field

The invention relates to the technical field of chains, in particular to a novel silent chain and an assembling method thereof.

Background

The silent chain is widely used for high-speed transmission engine timing systems of automobiles, motorcycles and the like. Compared with a roller chain, the mute chain has better NVH characteristic, can effectively reduce the noise of a chain transmission system, and improves the sound quality. The silent chain is composed of a plurality of same guide plates, working chain plates and connecting pin shafts. Because there is certain limitation in structural design in traditional silence chain, can influence wear resistance. As shown in fig. 1, in the conventional working link plate of the silent chain, the pin shaft and the working link plate are in shaft hole clearance fit, the pin hole is of a standard circular structure, the radius of curvature of the circular arc of the pin shaft inserted into the pin hole of the link plate is R1', the radius of curvature of the circular arc of the pin hole of the link plate is R2', in order to ensure that the pin shaft can be loosely inserted into the pin hole of the link plate, R1' and R2' need to satisfy a relational expression, R2' + N ', and N ' ═ 0.02-0.04, although the problems of assembly quality and efficiency of the silent chain can be fundamentally solved, the center of curvature of the circular arc of the pin hole of the pin shaft is the pitch center of the chain, the center of curvature of the circular arc of the pin hole of the pin shaft and the pitch center of the chain are on the same straight line, and the clearance between the pin shaft and the pin hole is large.

Because of the improvement of global energy conservation and environmental awareness, the automobile tends to be light in weight, and the engine is more and more compact, the timing chain of the engine is required to be designed to be as small as possible, so that the difficulty in producing and manufacturing the chain is greatly increased. The main dimension of the silent chain is called pitch, and the specifications of the silent chain are as follows:

6.35mm, 8mm, 9.525mm and the like. The fit clearance of the pin holes of the silent chain is designed to be smaller, the precision is higher, the manufacturing difficulty is higher, the pin shafts and the chain plate holes are easily extruded and cut, and defective products such as eyebrow-shaped scrap irons, tight joints, dead joints and the like are generated. The existence of the iron chips can compress an oil storage space of the pin hole and even block a lubricating oil circulating system of the oil pump, so that the normal work of the engine is seriously influenced, and the service life of the engine is finally reduced.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the novel silent chain and the assembling method thereof, the abrasion resistance is good, the oil storage space is increased, the production efficiency is improved, the manufacturing risk is reduced, and the service life is effectively prolonged.

In order to achieve the purpose, the invention is realized by the following technical scheme: the utility model provides a novel silence chain, comprises a plurality of work link joint, the round pin axle and the baffle of connecting the work link joint, the round pin axle inserts in the work link joint, and with baffle interference fit, there is side clearance between work link joint and the baffle. The requirements of installation matching and meshing transmission are met.

Preferably: the working chain plate consists of a pair of pin holes, a pair of teeth and a tooth top, the pin holes are of irregular circular structures formed by multiple sections of circular arcs, and the pin shafts are inserted into the circular pin holes.

Preferably: the pin hole is composed of an engaged working arc AB section, a transition arc BC section, a transition arc CD section, a transition arc EF section, a transition arc FA section and an assembly oil storage arc DE section which are of a certain length.

Preferably: the arc curvature centers O1 and O1' of the pin shaft are the pitch centers of the chain, and the curvature center O2 of the meshing working arc AB section and the curvature center O3 of the assembly oil storage arc DE section of the pin hole are on the same straight line with the pitch center of the chain.

Preferably: the radius of curvature R2 of the engagement working arc AB section of the pin hole is greater than or equal to the radius of curvature R1 of the arc of the pin inserted into the hole.

Preferably: the curvature radius R3 of the DE section of the oil storage arc for assembling the pin hole is larger than the curvature radius R2 of the AB section of the meshing working arc, so that R1, R2 and R3 meet the relation that R3 is larger than R2 and is larger than or equal to R1, and the pin shaft can be easily inserted into the pin hole.

A novel silent chain assembling method is characterized by comprising the following steps:

s1, assembling the working chain plate, the pin shaft for connecting the working chain plate and the guide plate into a chain;

s2, pre-tensioning is needed, the pre-tensioning force is 60% -90% of the broken load of the chain, and the pre-tensioning holding time is 0-120 seconds;

s3, after pre-tensioning, the arc at one side of the pin shaft is tightly attached to the side of the AB section of the engagement working arc of the working chain plate, and a gap is formed between the assembly oil storage arc DE and the arc at the other side of the pin shaft.

Preferably: the size of a gap between the assembling oil storage arc DE and the arc on the other side of the pin shaft is 1% -5% of the chain pitch, lubricating oil is filled in the gap, a precondition is laid for formation of a dynamic pressure oil film, the pin shaft is always wrapped in the oil film and is in contact with pin holes of the working chain plates, the oil storage space is enlarged, lubrication of the chain system is promoted, noise is reduced when the silent chain moves at a high speed due to the dynamic pressure oil film, and the service lives of the silent chain system and an engine are prolonged.

The invention has the following beneficial effects:

the working chain plate can increase the contact area of the hinge by reducing the fit clearance between the working chain plate and the pin shaft on the premise of not reducing the strength of the chain plate, and effectively reduces the contact stress of the hinge, thereby obtaining the best wear resistance. The DE section of the oil storage arc is designed and assembled, so that the oil storage space is increased, and meanwhile, the production efficiency of the silent chain is improved, namely, the pin shaft can be easily inserted into the pin hole of the working chain plate, the risks of hole cutting, joint tightening and the like in the manufacturing process are fundamentally reduced, and the service life of the chain transmission system can be effectively prolonged.

Drawings

Fig. 1 is a view of a conventional silent chain with its link plate and pin engaged, as described in the background of the invention.

FIG. 2 is a front elevational view of a work link plate of the present invention;

FIG. 3 is a schematic view of the invention with the pin loosely inserted into the work link plate;

FIG. 4 is an enlarged view of a portion of FIG. 3;

FIG. 5 is a view showing the engagement between the pre-stretched link plate and the pin shaft according to the present invention;

FIG. 6 is an enlarged view of the pin bore of FIG. 5;

fig. 7 is a front view of a silent chain in the present invention;

fig. 8 is a top view of a mute chain in the present invention;

FIG. 9 is an enlarged fragmentary schematic view of the reservoir space of FIG. 8;

FIG. 10 is a pin hole fit clearance versus hinge contact stress in the present invention;

fig. 11 shows the results of a comparative test of the wear performance of the novel silent chain of the present invention and the conventional silent chain.

Reference numerals: 1. a silent chain; 2. a working chain plate; 3. a pin shaft; 4. a guide plate; 21. a pin hole; 22. teeth; 23. tooth top; 22a, an inner side surface; 22b, an outer side surface; 31. an oil storage space.

Detailed Description

The preferred embodiments of the present invention will be described in further detail with reference to the accompanying drawings.

The novel silent chain as shown in fig. 2-11 comprises a plurality of working chain plates 2, pin shafts 3 connecting the working chain plates 2, and guide plates 4, wherein the pin shafts 3 are inserted into the working chain plates 2 and are in interference fit with the guide plates 4, and lateral gaps are formed between the working chain plates 2 and the guide plates 4. The requirements of installation matching and meshing transmission are met. The link plate 2 is composed of a pair of pin holes 21, a pair of teeth 22 formed by an inside flank surface 22a and an outside flank surface 22b hanging downward from the pin holes 21 in a triangular shape, and a tooth crest 23, the pin holes 21 are formed by a plurality of circular arcs into an irregular circular structure, and the pin shafts 3 are inserted into the circular pin holes 21. The pin hole 21 is composed of an engagement working arc AB section, a transition arc BC section, a transition arc CD section, a transition arc EF section, a transition arc FA section and an assembly oil storage arc DE section with certain length.

The arc curvature centers O1 and O1' of the pin shaft 3 are the pitch centers of the chain, and the curvature center O2 of the meshing working arc AB section and the curvature center O3 of the assembly oil storage arc DE section of the pin hole 21 are on the same straight line with the pitch centers of the chain. The radius of curvature R2 of the engagement working arc AB section of the pin hole 21 is similar to or equal to the radius of curvature R1 of the arc of the pin shaft 3 inserted into the hole. The curvature radius R3 of the assembly oil storage arc DE section of the pin hole 21 is larger than the curvature radius R2 of the engagement working arc AB section, so that R1, R2 and R3 meet the relation that R3 is larger than R2 and is larger than or equal to R1, R2 is R1+ N, N is 0-0.04, and the pin shaft 3 can be easily inserted into the pin hole 21. The design can increase the contact area of the hinge and reduce the contact stress, when the tight edge tension of the chain is kept at 2000N, when the fit clearance between R1 and R2 is changed, the contact stress of the hinge is changed to a certain extent, when R2 is closer to R1, the clearance fit between the R1 and the R2 is smaller, the contact area of the hinge is increased, and the contact stress is reduced, so that the wear elongation of the silent chain is reduced fundamentally, the wear resistance of the silent chain is improved greatly, and the service life of an engine is prolonged.

According to the invention, the working chain plate 2 can reduce the fit clearance between the working chain plate 2 and the pin shaft 3 on the premise of not reducing the strength of the chain plate, so that the contact area of the hinge is increased, the contact stress of the hinge is effectively reduced, and the optimal wear resistance is obtained. The DE section of the oil storage arc is designed and assembled, the production efficiency of the silent chain is improved while the oil storage space is increased, namely, the pin shaft 3 can be easily inserted into the pin hole 21 of the working chain plate 2, the risks of hole cutting, joint tightening and the like in the manufacturing process are fundamentally reduced, and the service life of the chain transmission system can be effectively prolonged.

A novel silent chain assembling method comprises the following steps:

s1, assembling the working chain plate, the pin shaft for connecting the working chain plate and the guide plate into a chain;

s2, pre-tensioning is needed, the pre-tensioning force is 60% of the breaking load of the chain, and the pre-tensioning holding time is 70 seconds;

s3, after pre-tensioning, one side arc of the pin shaft is tightly attached to one side of an AB section of an engaged working arc of the working chain plate, a gap is formed between an assembly oil storage arc DE and the other side arc of the pin shaft, the gap between the assembly oil storage arc DE and the other side arc of the pin shaft is 1% -5% of the chain pitch, the gap is represented by delta 2, an oil storage space where the gap is located can be used for storing enough lubricating oil, a precondition is laid for the formation of a dynamic pressure oil film, the timing chain system of the automobile engine belongs to typical high-speed transmission and needs continuous pressure oil injection lubrication, the lubricating oil flows from one side of a larger oil storage space to a smaller gap, the pin shaft slides relatively in a pin hole of the working chain plate, the pin shaft is always wrapped in the oil film to be in contact with the pin hole of the working chain plate, and the oil storage space is increased to be beneficial to improving the lubrication, the presence of the hydrodynamic oil film ensures that the silent chain reduces noise during high speed motion and extends the life of the silent chain system and the engine.

The △ 2 value and the P value in the invention need to satisfy the following relational expression that △ 2 is (1% -5%) P, for example, P is 8mm, R1 is 1.66mm, R2 is 1.68mm, R3 is 1.85mm, the residual gap △ 2 is 0.32mm after the chain plate is tightly matched with the pin shaft, and the corresponding oil storage space area is 1.6mm²Referring to fig. 1 of the prior art, the gap △ 1 left after the working chain plate is matched with the pin shaft is 0.06mm, and the area of the corresponding oil storage space is 0.21 mm². Obviously, the area of the oil storage space is multiplied by the thickness of the chain plate to form the oil storage space, and the oil storage amount in the silent chain is more than 7 times larger than that of the traditional silent chain.

As can be seen from fig. 7, 8 and 9, the position and the flowing direction of the lubricating oil in the silent chain have the condition of forming a dynamic pressure oil film, the lubricating oil can flow into the pin hole from the side clearance between the guide plate and the operating link plate, the side clearance is represented by Δ H, the oil is stored in the clearance between the pin shaft and the pin hole, the Δ H value can be designed to be 0.4-0.8 mm according to the requirement of the manufacturing process, the Δ H value in the embodiment is 0.5, the transverse width of the end of K1 is 0.32mm, and the transverse width of the minimum end of K2 is 0.04 mm. The pin shaft of the silent chain is driven by a load to slide relative to the working chain plate, lubricating oil is extruded, continuously flows into the large-section K1 end of the wedge-shaped hole and flows out of the small-section K2 end of the wedge-shaped hole, the forming condition of a dynamic pressure oil film is met, heat dissipation during hinge friction is facilitated, the lubricating effect is improved, friction loss is reduced, and the service life of the whole chain transmission system is finally prolonged.