JP2010281383A - Curved surface type chain guide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curved surface type chain guide for stably and smoothly sliding and traveling a transmission chain even if installation accuracy is reduced, by reducing partial abrasion of a chain traveling surface by slidingly contacting on chain both sides with the chain traveling surface even if flapping is caused in the transmission chain when starting an engine, by improving fuel consumption performance in the engine by reducing a friction loss when a chain travels. <P>SOLUTION: In this curved surface type chain guide 100, a travel guide surface 111 for guiding the transmission chain C rises in a curved shape toward right-left guide side edge parts 111b and 111b of a guide central part 111a in the guide width direction, by slidingly contacting with a plate end surface of a link plate for constituting the transmission chain C. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a roller chain that circulates between a driving side sprocket and a driven side sprocket, and a transmission device such as a silent chain that transmits power by a transmission chain such as a silent chain. The present invention relates to a chain guide that is used as a fixed guide that guides traveling or a movable guide that guides and tensions a transmission chain in a sliding contact state.

Conventionally, as a guide for such a transmission device, a shoe 510 for sliding a timing chain C used in an automobile engine as shown in FIG. 6 and a guide body 520 for supporting and reinforcing the shoe 510 are provided. A chain guide 500 is known.
In such a chain guide 500, a pair of left and right chain restriction side walls 512, 512 for restricting meandering travel of the timing chain C are arranged on the side of the chain travel surface 511 of the shoe 510, respectively. The chain travel line is held by forcibly preventing the dropout.

  That is, the wall height of the chain regulating side wall 512 described above is made lower than the pin outer peripheral surface height of the timing chain C to ensure a clearance that can avoid contact between the pin outer peripheral surface and the chain restricting side wall 5121, so The link plate of the chain C is slid on the chain running surface 511, and the link plate of the timing chain C is brought into contact with the inward surface of the chain regulating side wall 511 during meandering running (for example, patent document). 1).

Patent No. 3448122 (Claims, FIG. 1)

  However, in the conventional chain guide 500 as described above, as shown in FIG. 7, the plate end surface of the link plate travels in sliding contact with the chain traveling surface 511 of the shoe 510 during normal chain traveling. However, there is a problem that the fuel consumption performance of the engine is reduced due to friction loss. On the other hand, if the timing chain C fluctuates greatly when the engine is started, the timing chain C comes into contact with the chain running surface 511 of the shoe 510 on one side. Thus, there is a problem that the chain running surface 511 of the shoe 510 is unevenly worn at an early stage.

  Further, in the conventional chain guide 500, since the wall height of the chain regulating side wall 511 is low, if the timing chain C flickers when the engine is started, it is shown in FIG. Such a state that the timing chain C rides on the chain regulation side wall 512 or a state where the timing chain C straddles the chain regulation side wall 512 as shown in FIG. There was a problem that I could not.

  Further, since the wall height of the chain regulating side wall 512 is low, when the timing chain C is assembled to the engine, the timing chain C as shown in FIG. 8 is on the chain regulating side wall 512 or the timing shown in FIG. When the chain C is mounted on the chain travel line with the chain regulating side wall 512 being straddled and the engine is started, the timing chain C crosses the chain regulating side wall 512 and falls off, and the timing chain C is detached from the sprocket. Not only is there a problem of damage, but even if such an improper assembly state can be found visually or tactilely, it requires a great work load to restore the proper assembly state. There was a serious problem.

  Therefore, the present invention solves the conventional problem. That is, the object of the present invention is to reduce the friction loss during chain running and improve the fuel efficiency of the engine, and to improve the fuel efficiency of the transmission chain when starting the engine. Curved chain that slides on the chain running surface on both sides of the chain to reduce uneven wear on the chain running surface even when flickering occurs, and allows the transmission chain to slide stably and smoothly even when the assembly accuracy is reduced Is to provide a guide.

  The present invention according to claim 1 is a curved chain guide provided with a chain running surface that guides the transmission chain by slidingly contacting a plate end surface of a link plate constituting the transmission chain, wherein the chain running surface is the chain running surface. In the guide width direction, the above-described problem is solved by rising in a curved shape from the guide center portion toward the left and right guide side edges.

  According to a second aspect of the present invention, in addition to the configuration according to the first aspect, the curved surface width of the chain travel surface is gradually narrowed from the chain entry side to the chain exit side of the chain travel surface. Thus, the above-described problems are further solved.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the radius of curvature of the chain travel surface is gradually decreased from the chain entry side to the chain exit side of the chain travel surface. Thus, the above-described problems are further solved.

  Therefore, the present invention is not only capable of guiding the transmission chain along the traveling locus by providing the chain traveling surface slidably contacting the plate end surface of the link plate constituting the transmission chain. A specific effect can be produced.

  That is, according to the curved chain guide of the present invention according to claim 1, the chain running surface rises in a curved shape from the guide center portion toward the left and right guide side edges, so that the link during normal chain running is provided. Since the plate end surface of the plate slides in contact with the chain running surface in a line contact state, the area of contact with the chain running surface is reduced, reducing friction loss and improving the fuel efficiency of the engine.

Also, even if the transmission chain flutters or bounces when the engine starts, the chain running surface that rises in a curved shape from the center of the guide toward the left and right side edges of the guide is left and right by the pressing force associated with the chain tension. In order to perform a so-called centering function that automatically returns the transmission chain that is unevenly distributed to one of the guide side edges toward the center of the guide, the transmission chain is slid stably and smoothly along the longitudinal direction of the guide. In addition to being able to travel dynamically, the transmission chain can be slid and traveled easily and smoothly even if the assembly accuracy with respect to the transmission chain is reduced.
In addition, since the transmission chain travels while reliably sliding on both sides of the chain travel surface, it is possible to reduce uneven wear in the one-side contact state that tends to occur on the chain travel surface.

  According to the curved chain guide of the present invention according to claim 2, in addition to the effect of the curved chain guide according to claim 1, the curved surface width of the chain traveling surface is changed from the chain entry side of the chain traveling surface to the chain. By gradually narrowing toward the exit side, even if rolling or jumping due to the transmission chain fluttering occurs on the chain entry side when starting the engine, the curved surface width gradually increases from the chain entry side toward the chain exit side. The narrow chain running surface is meandering on the chain entry side to regulate while gradually guiding it toward the center of the guide in the guide width direction while sliding the transmission chain by the pressing force accompanying the chain tension. The transmission chain can be slid and run more stably and smoothly in the longitudinal direction of the guide from the chain entry side to the chain exit side. Kill.

  According to the curved chain guide of the present invention according to claim 3, in addition to the effect exhibited by the curved chain guide according to claim 1 or 2, the curved radius of the chain traveling surface is such that the chain entrance of the chain traveling surface is increased. Since the width gradually decreases from the side toward the chain exit side, even if rolling or jumping due to the transmission chain fluttering occurs at the chain entry side when the engine is started, such a fluttering transmission chain is It can be easily received upward, and can be reliably regulated while being gradually guided toward the center of the guide in the guide width direction while sliding the transmission chain.

The usage aspect figure of the curved type chain guide which is one Example of this invention. The perspective view which decomposed | disassembled the curved type chain guide which is one Example of this invention. FIG. 3 is a perspective view of the AA cross section of FIG. Explanatory drawing of the guide cross-sectional form in the guide longitudinal direction seen with the curved surface width and curved radius of the chain running surface. The centering function of a transmission chain is demonstrated, Comprising: (a) is explanatory drawing of the centering function in the driving | running state leaning to the left side, (b) is the centering function in the state which carries out sliding movement normally. (C) is explanatory drawing of the centering function in the driving | running state leaning to the right side. The perspective view which decomposed | disassembled the conventional chain guide. Explanatory drawing of the state which is carrying out sliding movement normally on a chain running surface. Explanatory drawing of the state which got on the chain regulation side wall from the chain running surface. Explanatory drawing of the state which straddled the chain regulation side wall from the chain running surface.

  The present invention relates to a curved chain guide having a chain running surface that guides a transmission chain by slidingly contacting a plate end surface of a link plate that constitutes the transmission chain. From the side to the left and right guide edges to reduce friction loss during chain running and improve engine fuel efficiency.If the transmission chain flutters when the engine starts, the chain running surface On the other hand, if the chain is slidably contacted on both sides to reduce uneven wear on the chain running surface, and the assembly accuracy is reduced, the transmission chain can be slid and run stably. It doesn't matter what it is.

  For example, the curved chain guide of the present invention is used in a transmission device that transmits power by a transmission chain such as a roller chain or a silent chain that circulates between a driving side sprocket and a driven side sprocket. Any guide may be used as long as it can guide travel, and it may be a fixed guide that guides the transmission chain in a sliding contact state or a movable guide that travels and guides the transmission chain in a sliding contact state.

  The specific material of the curved chain guide of the present invention may be any material as long as it has a low frictional resistance with the transmission chain. In particular, the curved chain guide exhibits durability in a high temperature environment and smoothly slides the transmission chain. A material that can achieve contact traveling is suitable. For example, a material such as a synthetic resin material such as polyamide 6 resin, polyamide 46 resin, polyamide 66 resin, or polyacetal resin is preferably used.

  As for a specific form of the curved chain guide of the present invention, a shoe provided with a chain running surface for guiding the transmission chain in a sliding contact state and a guide body supporting the shoe are assembled separately. It is possible to use any one of these, or one in which these shoes and the guide body are integrally molded.

  Furthermore, the specific shape of the chain running surface formed in the curved chain guide of the present invention is curved and symmetrical in the guide width direction of the chain running surface from the center of the guide toward the left and right guide side edges. It is sufficient that the transmission chain is slid and travels in a sliding manner, and may be formed in an arc shape with a single bending radius or a plurality of bending radii.

Hereinafter, a curved chain guide 100 according to an embodiment of the present invention will be described with reference to the drawings.
Here, FIG. 1 is a usage diagram of a curved chain guide that is an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the curved chain guide that is an embodiment of the present invention. 3 is a perspective view cut out in the AA cross section of FIG. 2, and FIG. 4 is an explanatory view of the guide cross section in the longitudinal direction of the guide as viewed from the curved surface width and the curved radius of the chain running surface FIG. 5 illustrates the centering function of the transmission chain. FIG. 5A is an explanatory diagram of the centering function in a traveling state inclined to the left side, and FIG. 5B is a normal sliding traveling state. It is explanatory drawing of the centering function in a state, (c) is explanatory drawing of the centering function in the driving | running | working state leaning to the right side.
The curved form of the chain running surface shown in FIGS. 1 to 5 is exaggerated in an arc-shaped cross section that can be recognized at first glance for easy understanding of the present invention. Needless to say, the cross-section is almost flat and cannot be recognized at first glance.

First, a curved chain guide 100 according to an embodiment of the present invention circulates between a driving sprocket S1 and a driven sprocket S2 of a timing system for an automobile engine as shown in FIGS. It is used as a movable guide that makes a transmission chain C composed of a roller chain to travel run and guide it in a sliding contact state.
The curved chain guide 100 according to the present embodiment supports a shoe 110 having a chain traveling surface 111 that slides on a plate end surface of a link plate that constitutes the transmission chain C and guides the transmission chain C, and the shoe 110. And a guide body 120 that reinforces.

  1 is a hydraulic tensioner for urging the curved chain guide 100 of the present embodiment toward the transmission chain C, and the reference numeral FG guides the transmission chain C in a sliding contact state. The reference numeral 111a is a guide center portion in the guide width direction of the chain running surface 111, and the reference numeral 111b is a guide side edge portion formed continuously from the guide center portion a of the chain running surface 111. Reference numeral 113 denotes a hook portion provided on the shoe 110 for assembling the shoe 110 integrally with the guide main body 120, and reference numeral 121 supports the curved chain guide 100 of this embodiment to the engine block. Therefore, reference numeral 122 denotes a tensioner pad portion that is urged against the hydraulic tensioner T. .

Therefore, a specific form of the chain running surface 111 that is most characteristic of the curved chain guide 100 of the present embodiment will be described in detail with reference to FIGS.
First, as shown in FIGS. 3 to 4, the chain running surface 111 of the curved chain guide 100 according to the present embodiment is curved and left and right from the guide center portion 111a toward the left and right guide side edges 111b and 111b. Standing up symmetrically.
The curved surface width W of the chain running surface 111 is gradually narrowed from the chain entry side to the chain exit side of the chain running surface 111.
Further, the radius of curvature R of the chain running surface 111 gradually decreases from the chain entry side to the chain exit side of the chain running surface 111.

  In the curved chain guide 100 of the present embodiment, the chain running surface 111 is formed with a single bending radius R, but is curved from the guide center portion 111a toward the left and right guide side edges 111b and 111b. Needless to say, the chain running surface 111 may be formed with a plurality of curved radii as long as the chain running surface 111 can be formed so as to rise symmetrically.

Next, the centering function generated on the chain running surface 111 will be described with reference to FIG.
In the curved chain guide 100 of the present embodiment, for example, when the engine is started, the transmission chain flutters and jumps due to the flapping of the transmission chain, and an external force F is applied, so that the transmission chain C as shown in FIG. When the traveling state is inclined and unevenly distributed to the side edge portion 111b, or the traveling state where the transmission chain C is inclined and unevenly distributed to the right guide side edge portion 111b as shown in FIG. As a result of the pressing force f accompanying the chain tension of the chain running surface 111 trying to press the transmission chain C evenly to the left and right, this pressing force f is selected to be a link plate that has run up to one side on the chain running surface 111. Therefore, a so-called centering function for automatically returning the transmission chain C toward the guide central portion 111a as shown in FIG. To.

  5 (b) in FIG. 5 from the traveling state in which the centering function is inclined and unevenly distributed to the guide side edge portion 111b of the transmission chain C as shown in FIG. 5 (a) or FIG. 5 (c). The pressing force f accompanying the chain tension on the chain running surface 111 automatically presses the transmission chain C on the chain running surface 111 to the left and right so that the transmission chain C slides securely on both sides of the chain running surface 111 automatically. Thus, the transmission chain C can be slid and traveled stably and smoothly along the longitudinal direction of the guide.

  Further, in the curved chain guide 100 of the present embodiment, the curved surface width W of the chain running surface 111 is gradually narrowed from the chain entry side to the chain exit side of the chain running surface 111, so that power is transmitted when the engine is started. Even if the chain C flutters or bounces due to fluttering on the chain entry side, the chain running surface 111 whose curved surface width W gradually decreases from the chain entry side to the chain exit side is pushed by the chain tension. Since the transmission chain C is slidably driven by pressure and regulated while being gradually guided toward the guide central portion 111a in the guide width direction, the transmission chain C meandering on the chain entry side is changed from the chain entry side to the chain exit side. The sliding movement is further stable and smooth in the longitudinal direction of the guide.

  Further, in the curved chain guide 100 of the present embodiment, the radius of curvature R of the chain running surface 111 gradually decreases from the chain entry side to the chain exit side of the chain running surface 111. Even if rolling or jumping due to C fluttering occurs on the chain entry side, such a fluttering transmission chain C can be easily received on the chain running surface 111 and the transmission chain C can be slid and run in the guide width direction. The guide is reliably regulated while being gradually guided toward the guide central portion 111a.

  In the curved chain guide 100 of this embodiment obtained in this way, the chain running surface 111 rises in a curved and bilaterally symmetrical manner from the guide center portion 111a toward the left and right guide side edges 111b and 111b. As a result, the plate end surface of the link plate travels in a linear contact state with the chain travel surface 111 during normal chain travel, so that the contact area with the chain travel surface 111 is reduced and friction loss is reduced. Even if the fuel efficiency is improved and the assembly accuracy with respect to the transmission chain C is reduced, the transmission chain C can be slid easily and smoothly, and the transmission chain C can be reliably slid on both sides of the chain running surface 111. To reduce uneven wear in the one-side contact state that tends to occur on the chain running surface 111 because it runs in contact Such as can be, the effect is enormous.

100: Curved chain guide 110 ... Shoe
111 ... Chain running surface
111a ... Guide center
111b ... guide side edge 113 ... hook part 120 ... guide body
121 ... Shaft support
122 ・ ・ ・ Tensioner pad
C ... Transmission chain S1 ... Drive side sprocket S2 ... Driven side sprocket T ... Hydraulic tensioner FG ... Fixed guide R ... Bending radius W ... Bending surface width F ... External force f ... Pressing force

Claims (3)

In a curved chain guide having a chain running surface that slidably contacts the plate end surface of the link plate constituting the transmission chain and guides the transmission chain,
The curved chain guide characterized in that the chain running surface rises in a curved shape from the guide central portion toward the left and right guide side edges in the guide width direction of the chain running surface.   The curved chain guide according to claim 1, wherein the curved surface width of the chain running surface is gradually narrowed from the chain entry side to the chain exit side of the chain running surface.   The curved chain guide according to claim 1 or 2, wherein a curvature radius of the chain running surface gradually decreases from a chain entry side to a chain withdrawal side of the chain running surface.

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