WO2019181690A1

WO2019181690A1 - Tensioner

Info

Publication number: WO2019181690A1
Application number: PCT/JP2019/010293
Authority: WO
Inventors: 貴雄小林; 山田　佳男; 和人平岡; 伊藤　敬一
Original assignee: 日本発條株式会社
Priority date: 2018-03-22
Filing date: 2019-03-13
Publication date: 2019-09-26
Also published as: JP7293192B2; JPWO2019181690A1

Abstract

This tensioner has: a tubular holding member; a movable member mounted to the holding member so as to be slidable in the axial direction; a thrust member mounted to the movable member so as to be relatively movable; a biasing member which is provided between the movable member and the thrust member, biases the thrust member outward in the axial direction of the holding member, and biases the movable member inward in the axial direction of the holding member; and a sliding force increasing means which is formed between and in contact with the movable member and the holding member, and which presses the movable member in a direction crossing the axial direction and thereby increases the sliding resistance between the thrust member and the holding member when the thrust member is moving.

Description

Tensioner

This disclosure relates to tensioners.

Japanese Patent Application Laid-Open No. 2005-344887 discloses a ring-type hydraulic tensioner that applies tension to a timing chain wound around a crankshaft and a camshaft of a vehicle engine. In this ring type hydraulic tensioner, a cylindrical plunger is inserted into the plunger receiving hole of the housing body. An annular groove is formed on the outer periphery of the cylindrical plunger, and a C-shaped ring is fitted into the annular groove. Further, the C-shaped ring is biased so as to increase in diameter toward the inner peripheral wall of the plunger receiving hole. Thereby, for example, even when an impact load is applied from the timing chain to the cylindrical plunger at the time of starting the engine, the C-shaped ring exhibits a buffering performance, and the rapid backward movement of the cylindrical plunger is suppressed.

In the ring type hydraulic tensioner disclosed in Japanese Patent Application Laid-Open No. 2005-344887, the C-shaped ring slides with the inner peripheral wall of the plunger accommodation hole as the plunger moves back and forth. Due to this sliding friction, the inner peripheral wall of the plunger receiving hole is worn. As a result, the gap between the inner peripheral wall of the plunger receiving hole and the outer peripheral surface of the plunger increases. In addition, wear and heat settling of the C-shaped ring occurs, and the diameter expansion force of the C-shaped ring decreases. In these cases, the buffering performance of the C-shaped ring may be reduced.

The present disclosure provides a tensioner in which the buffering performance for suppressing rapid movement of the cylindrical plunger (propulsion member) is unlikely to deteriorate.

The tensioner of the first aspect includes a cylindrical holding member, an idler member that is slidably attached to the retainer member in the axial direction, a propulsion member that is attached to the idler member so as to be relatively movable, and the idler member And an urging member that urges the propulsion member axially outward of the holding member and urges the floating member axially inward of the holding member; and the floating member When the propulsion member moves, it presses the floating member in a direction intersecting the axial direction to slide the propulsion member and the holding member. Sliding force increasing means for increasing the resistance.

In the tensioner according to the first aspect, the propulsion member moves outward in the axial direction of the holding member by the urging force of the urging member. On the other hand, the floating member moves inward in the axial direction of the holding member by the urging force of the urging member. At this time, the sliding force increasing means formed in contact with the floating member and the holding member presses the propelling member together with the floating member in a direction crossing the axial direction. For this reason, the sliding resistance between the propelling member and the holding member is increased. Thereby, the sliding speed of a propulsion member becomes slow and a buffer function is exhibited.

Further, when a force in a direction of pushing the propulsion member back in the axial direction of the holding member acts on the propulsion member, the propulsion member is pushed back in the axial direction of the holding member together with the floating member against the biasing force of the biasing member. . Also at this time, since the idler member moves inward in the axial direction of the holding member, the sliding force increasing means presses the propelling member together with the idler member in a direction crossing the axial direction. For this reason, the sliding resistance between the propelling member and the holding member is increased. Thereby, the sliding speed of a propulsion member becomes slow and a buffer function is exhibited.

Thus, in the tensioner of the first aspect, the urging member, the floating member, the holding member, and the sliding force increasing means are related to each other to exhibit a buffering performance. For this reason, it is difficult for the load to concentrate on a specific member, and the buffering performance is not easily lowered.

In contrast, for example, when a C-shaped ring or the like is disposed around the propelling member and the buffering performance is exhibited by the spring load of the C-shaped ring, the buffering performance depends only on the C-shaped ring. For this reason, if physical degradation occurs in the C-shaped ring, the buffering performance tends to be lowered.

In the tensioner according to the second aspect, the sliding force increasing means is formed on the inner peripheral surface of the holding member and expands from the inner side in the axial direction to the outer side in the axial direction of the holding member. A diameter portion, and a wedge portion formed on the floating member and in contact with the enlarged diameter portion.

In the tensioner according to the second aspect, the enlarged diameter portion is formed on the inner peripheral surface of the holding member. The diameter-expanded portion increases in diameter from the inner side in the axial direction to the outer side in the axial direction of the holding member toward the outer side in the radial direction of the holding member. When the idler member moves inward in the axial direction of the holding member by the urging force of the urging member, the wedge portion in contact with the enlarged diameter portion is pressed from the enlarged diameter portion in a direction crossing the axial direction of the holding member. This increases the sliding resistance between the propelling member and the holding member.

In the tensioner of the third aspect, at least one of the enlarged diameter portion and the wedge portion in contact with the enlarged diameter portion gradually increases in diameter from the inner side in the axial direction to the outer side in the axial direction of the holding member. A changing inclined surface is formed.

In the tensioner of the third aspect, an inclined surface that gradually changes in diameter is formed in the enlarged diameter portion or the wedge portion. For this reason, when the floating member is moved inward in the axial direction of the holding member by the urging force of the urging member, the pressing force from the enlarged diameter portion to the wedge portion gradually increases. Thereby, smooth buffer performance can be exhibited.

In the tensioner of the fourth aspect, the inclined surface is formed on both the enlarged diameter portion and the wedge portion in contact with the enlarged diameter portion.

In the tensioner according to the fourth aspect, since the inclined surface is formed on both the enlarged diameter portion and the wedge portion in contact with the enlarged diameter portion, the floating member can easily move inward in the axial direction of the holding member. For this reason, it is easy to obtain buffer performance.

In the tensioner according to the fifth aspect, the inclination angle of the inclined surface is 30 ° or more and 60 ° or less with respect to the axial direction of the holding member.

In the tensioner of the fifth aspect, since the inclination angle of the inclined surface is 60 ° or less with respect to the axial direction of the holding member, the wedge portion even if the urging force of the urging means is small compared to the case where it is larger than 60 °. Is easy to move inward in the axial direction of the holding member while in contact with the inclined surface. Further, since the inclination angle of the inclined surface is 30 ° or more with respect to the axial direction of the holding member, the urging force of the urging means and the propelling member are pushed back to the inside of the holding member as compared with the case where it is smaller than 30 ° Even if the directional force is large, the wedge portion is difficult to move inward in the axial direction of the holding member while being in contact with the inclined surface.

The tensioner according to the sixth aspect includes movement restraining means for restraining the propelling member from moving inward in the axial direction.

According to the tensioner of the sixth aspect, the movement restraining means restrains the propulsion member from moving inside the holding member. For this reason, even when the propulsion member is strongly pressed inward, the propulsion member can be prevented from moving inward. Thereby, the buffering effect can be enhanced.

In the tensioner according to the seventh aspect, the movement suppressing means is a concavo-convex portion that is provided on a contact surface between the wedge portion and the propelling member and engages with each other.

According to the tensioner of the seventh aspect, the concave and convex portions that engage with each other are provided between the wedge portion of the floating member and the propulsion member. For this reason, when the wedge portion is pressed from the holding member, the concavo-convex portions mesh with each other. Thereby, it can suppress that a propelling member moves inside.

</ RTI> According to the tensioner according to the present disclosure, the buffering performance for suppressing the rapid displacement of the propelling member is unlikely to deteriorate.

It is an elevation view showing the state where the tensioner concerning a 1st embodiment of this indication was fixed to the engine. It is sectional drawing which shows the state which the coil spring contracted in the tensioner which concerns on 1st Embodiment of this indication. It is sectional drawing which shows the state which the coil spring extended in the tensioner which concerns on 1st Embodiment of this indication. It is sectional drawing which shows the housing in the tensioner which concerns on 1st Embodiment of this indication. It is a front view showing a housing in a tensioner concerning a 1st embodiment of this indication. It is sectional drawing which shows the plunger in the tensioner which concerns on 1st Embodiment of this indication. It is a front view showing a plunger in a tensioner concerning a 1st embodiment of this indication. It is sectional drawing which shows the floating member in the tensioner which concerns on 1st Embodiment of this indication. It is a front view showing a floating member in a tensioner concerning a 1st embodiment of this indication. It is sectional drawing which showed the state which the tensioner which concerns on 1st Embodiment of this indication is pressing the chain guide. It is sectional drawing which showed the state which the tensioner which concerns on 1st Embodiment of this indication presses a chain guide, and is further pressed from the chain guide. It is a graph which shows the stroke characteristic of the tensioner concerning a 1st embodiment of this indication. In the tensioner concerning a 1st embodiment of this indication, it is a sectional view showing the modification which notched the guide groove of the housing. In the tensioner which concerns on 1st Embodiment of this indication, it is sectional drawing which shows the modification which formed the protrusion part in the floating member. It is sectional drawing which shows the tensioner which concerns on 2nd Embodiment of this indication. It is a sectional view showing a tensioner concerning a 3rd embodiment of this indication. It is a front view showing a tensioner concerning a 3rd embodiment of this indication. It is sectional drawing which shows the tensioner which concerns on 4th Embodiment of this indication.

[First Embodiment]
(Tensioner)
As shown in FIG. 1, an engine 100 to which a tensioner 10 according to the first embodiment of the present disclosure is attached includes a driving side sprocket 102 attached to a crankshaft and a driven side sprocket 104 attached to a camshaft. Further, a timing chain 106 is wound around.

The tensioner 10 includes a housing 20 and a plunger 30. The housing 20 is fixed to the engine 100 with bolts 12. The plunger 30 is inserted into the housing 20. The plunger 30 biased in the direction away from the housing 20 presses the chain guide 110 that rotates about the support shaft 108 with the propulsive force P. The chain guide 110 presses the timing chain 106.

2A and 2B, the tensioner 10 is disposed between the housing 20, the plunger 30 inserted into the housing 20 and movable along the axial direction of the housing 20, and the housing 20 and the plunger 30. And a floating member 40.

(housing)
As illustrated in FIGS. 3A and 3B, the housing 20 as an example of a holding member in the present disclosure is a bottomed cylindrical member. The housing 20 includes a substantially circular insertion hole 22, a guide groove 24 formed in the upper part of the insertion hole 22 along the insertion hole 22, and a guide groove 26 formed in the lower part of the insertion hole 22. . An inclined surface 24 A is formed from the inner side of the insertion hole 22 to the outer side at the outer end portion of the guide groove 24 (that is, the peripheral edge portion of the entrance / exit of the plunger 30 described later). The inclined surface 24A gradually changes in diameter in a direction away from the central axis CL of the insertion hole 22 (in other words, gradually inclines from the outside toward the inside in the radial direction of the housing 20). The inclination angle of the inclined surface 24A is an angle θ1 with respect to the central axis CL. Note that the inclined surface 24A is an example of a diameter-expanded portion in the present disclosure.

The above “upper” and “lower” indicate directions on the paper surface of FIG. 3, and do not indicate directions in a state of being attached to the engine 100 shown in FIG. 1. Further, “inside” indicates the hole bottom 22A side (axially inside, arrow IN side in FIG. 3A) of the insertion hole 22, and “outside” indicates the opening end 22B side (axially outside, FIG. 3A) of the insertion hole 22. 3A shows an arrow OUT side). The same applies to “upper part”, “lower part”, “inner side” and “outer side” used in the following description.

The flange 28 which the bolt hole 28A penetrated is formed in the upper part and the lower part of the housing 20. As shown in FIG. 1, the flange 28 is fixed to the engine 100 using bolts 12.

Further, as shown in FIG. 3B, the housing 20 is formed with a screw hole 29 penetrating from the outer peripheral surface side of the housing 20 to the insertion hole 22. By screwing a holding screw 52 into the screw hole 29, a plunger 30 described later can be temporarily fixed inside the insertion hole 22.

(Plunger)
As shown in FIGS. 4A and 4B, the plunger 30 as an example of the propelling member in the present disclosure is a bottomed cylindrical member. The plunger 30 includes a circular insertion hole 32 and a guide protrusion 34. The guide protrusion 34 is formed on the opening end 32 B side of the insertion hole 32 and projects outward in the radial direction of the insertion hole 32. As shown in FIG. 2A, the plunger 30 has the insertion end 32 of the insertion hole 32 facing the inside of the insertion hole 22 of the housing 20, and the guide protrusion 34 is fitted in the guide groove 26 of the housing 20. In this way, it is inserted into the insertion hole 22 of the housing 20. The outer diameter of the plunger 30 is a dimension that does not hinder the insertion of the plunger 30 into the insertion hole 22 of the housing 20, and is a dimension that substantially matches the inner diameter of the insertion hole 22.

(Floating member)
As shown in FIGS. 5A and 5B, the floating member 40 is a member formed in an L shape in a cross-sectional view, and extends in a direction substantially orthogonal to the bottom portion 42 from the circular bottom portion 42 and the outer peripheral end of the bottom portion 42. And a sliding portion 44 that is brought out.

In the sliding portion 44, a wedge portion 44A is formed at the end opposite to the bottom portion. The wedge portion 44 A is formed to be thicker than the other portion of the sliding portion 44, and has an inclined surface 44 AE whose outer peripheral surface is inclined in a direction away from the bottom portion 42. The inclination angle of the inclined surface 44AE (that is, the inclination angle with respect to the extending direction of the sliding portion 44) is equal to the inclination angle of the inclined surface 24A formed in the guide groove 24 of the housing 20 and is an angle θ1.

As shown in FIG. 2A, the floating member 40 is inserted into the insertion hole 22 of the housing 20 so that the bottom 42 is disposed inside the plunger 30 and the sliding portion 44 is fitted in the guide groove 24 of the housing 20. Is done. Further, the floating member 40 has an outer end portion of the sliding portion 44 protruding outside the housing 20 (guide groove 24), and an inclined surface 44AE of the wedge portion 44A abuts on an inclined surface 24A of the guide groove 24, It is arranged inside the insertion hole 22. At this time, the wedge portion 44 A is disposed on the radially inner side of the insertion hole 22 in the housing 20 and on the outer side in the axial direction of the insertion hole 22 with respect to the inclined surface 24 A. The wedge portion 44A and the inclined surface 24A of the guide groove 24 are an example of a sliding force increasing unit in the present disclosure.

The inner peripheral surface 44B of the sliding portion 44 of the floating member 40 is a concave surface having the same curvature as the outer peripheral surface 30A of the plunger 30. The inner peripheral surface 44B and the outer peripheral surface 30A are arranged so as to be in surface contact with each other. Further, the bottom portion 42 of the floating member 40 is formed with a clearance (space V) from the hole bottom 22A of the insertion hole 22 of the housing 20, so that the floating member 40 can move inward.

(Coil spring)
As shown in FIG. 2A, a coil spring 50 is disposed between the plunger 30 and the bottom portion 42 of the floating member 40 to bias the plunger 30 outward and bias the floating member 40 inward. The coil spring 50 is an example of an urging member in the present disclosure, and is inserted into the insertion hole 32 of the plunger 30. The coil spring 50 is disposed between the hole bottom 32 A of the insertion hole 32 and the bottom portion 42 of the floating member 40 in a state where the coil spring 50 is contracted from the free height (that is, the height when no load is applied).

As shown in FIG. 2B, the plunger 30 moves outward by the biasing force of the coil spring 50. At this time, the guide protrusion 34 of the plunger 30 moves along the guide groove 26 of the housing 20. A retaining member 60 is locked to the leading end of the guide groove 26. The movement of the plunger 30 is stopped by the guide protrusion 34 coming into contact with the retaining member 60.

(Action / Effect)
In the tensioner 10 of the first embodiment, as shown in FIG. 6, the plunger 30 receives an urging force P 1 directed outward from the coil spring 50 (P 1 is a spring load). Similarly, the floating member 40 receives an urging force P 1 directed inward from the coil spring 50. The floating member 40 is pulled into the insertion hole 22 by the urging force P1. Then, the wedge portion 44 A formed on the sliding portion 44 of the floating member 40 presses the inclined surface 24 A formed on the guide groove 24 of the housing 20.

Thereby, the wedge portion 44A receives the reaction force Pb along the normal direction of the inclined surface 44AE of the wedge portion 44A from the inclined surface 24A of the housing 20. Further, the reaction force Pb is transmitted through the inside of the floating member 40 and acts on the outer peripheral surface of the plunger 30 as a pressing force Pa. The pressing force Pa is obtained by dividing the reaction force Pb into “force in the direction along the axial direction” and “force in the direction orthogonal to the axial direction” of the plunger 30 and “force in the direction orthogonal to the axial direction”. Is equivalent to "

Furthermore, the pressing force Pa is transmitted through the inside of the plunger 30 and presses the inner peripheral surface 22C of the insertion hole 22. Thereby, the outer peripheral surface of the plunger 30 receives a pressing force Pa as a reaction force from the inner peripheral surface 22 C of the insertion hole 22.

Here, when the friction coefficient between the floating member 40 and the plunger 30 and the friction coefficient between the plunger 30 and the housing 20 are both μ, the plunger 30 receives a sliding resistance Ps = from each of the floating member 40 and the housing 20. (2 × Pa × μ). Thereby, the plunger 30 presses the chain guide 110 with the propulsion load PF1 = (P1−Ps).

When the engine 100 (see FIG. 1) is driven, tension is applied to the timing chain 106 with cam torque fluctuations. Then, as shown in FIG. 7, the plunger 30 receives a pressing force P 2 from the chain guide 110. This pressing force P 2 is transmitted to the floating member 40 via the coil spring 50.

Therefore, as compared with the case where the plunger 30 does not receive the pressing force P2 from the chain guide 110, the pressing force by which the wedge portion 44A of the floating member 40 presses the inclined surface 24A of the housing 20 becomes large. For this reason, the reaction force PB received by the wedge portion 44A from the inclined surface 24A, the pressing force PA acting on the outer peripheral surface of the plunger 30, and the sliding resistance force PS received by the plunger 30 from the floating member 40 and the housing 20 are respectively the above-mentioned reaction forces. It becomes larger than the force Pb, the pressing force Pa, and the sliding resistance force Ps. Therefore, the propulsion load PF2 = (P1-PS) at which the plunger 30 presses the chain guide 110 is smaller than the propulsion load PF1 = (P1-Ps).

Here, FIG. 8 shows an urging force P1 due to the coil spring 50, a sliding resistance force Ps when the pressing force P2 is not received from the chain guide 110, and a sliding resistance when the pressing force P2 is received from the chain guide 110. The stroke characteristic of the plunger 30 in consideration of the force PS is shown by a solid line. Further, the stroke characteristics of the coil spring 50 alone are indicated by a two-dot chain line. The coil spring 50 has a larger spring load when the stroke from the free height (that is, the amount of contraction) is larger, and the spring load is smaller when the stroke is smaller.

As shown in FIG. 8, when the plunger 30 is propelled (ie, moved to the outside of the insertion hole 22), the propulsion load PF1 = (P1-Ps) that presses the chain guide 110 is retracted (ie, the insertion hole). The retraction load PF3 = (P1 + PS) on the plunger 30 “necessary” when moving to the inside of 22 is larger by the sum of the sliding resistance forces Ps and PS (Ps + PS). As a result, a hysteresis characteristic is generated in the relationship between the stroke of the plunger 30 and the load, and the vibrations of the timing chain 106 and the chain guide 110 can be effectively damped.

That is, since the tensioner 10 according to the first embodiment uses the floating member 40, the plunger 30 is prevented from abruptly propelling when the plunger 30 is propelled, as compared with the case where the coil spring 50 is used alone. Further, the tensioner 10 gently presses the chain guide 110 to suppress fluttering of the timing chain 106. In addition, when the engine 100 is driven and the timing chain 106 flutters, the tensioner 10 exerts a large resistance force to restrain the plunger 30 from retreating, and fluttering can be restrained.

Further, the tensioner 10 presses the chain guide 110 with a small propulsive force as compared with the case where the coil spring 50 is used alone. For this reason, sliding friction between the chain guide 110 and the timing chain 106 can be reduced. Thereby, generation | occurrence | production of mechanical loss can be suppressed.

Further, in the tensioner 10, the outer diameter of the plunger 30 is set to a dimension that substantially matches the inner diameter of the insertion hole 22. Furthermore, the inner peripheral surface 44 B of the floating member 40 is in surface contact with the outer peripheral surface 30 A of the plunger 30. For this reason, the pressing force Pa acts on the plunger 30 in a plane. For this reason, the plunger 30 is unlikely to be worn, and the buffering performance of the tensioner 10 is unlikely to decrease.

In the tensioner 10, the wedge portion 44 A of the floating member 40 presses the inclined surface 24 A formed in the guide groove 24 of the housing 20. As a result, sliding resistance acts on the plunger 30. When the wedge portion 44A is worn as indicated by a broken line as the inclined surface 44AE in FIG. 2, the loose member 40 is disposed inside the insertion hole 22 by the amount of wear as indicated by an arrow M. For this reason, the sliding resistance is hardly reduced due to wear. The same applies when the inclined surface 24A is worn.

In the tensioner 10, a strong sliding resistance PS is generated when the plunger 30 is retracted. This sliding resistance PS varies depending on the pressing force P 2 that the plunger 30 receives from the chain guide 110. That is, as the pressing force P2 increases, the sliding resistance PS increases. For this reason, high sliding resistance PS can be exhibited according to the magnitude of the pressing force P2.

On the other hand, when the floating member 40 is not used, for example, a C-shaped ring or the like urged so as to expand the diameter is disposed between the outer peripheral surface 30A of the plunger 30 and the inner peripheral surface 22C of the insertion hole 22. (When configured differently from the present disclosure), it is possible to obtain a sliding resistance of “a certain size”, but it is difficult to obtain a sliding resistance according to the magnitude of the pressing force P2.

In addition, when a C-type ring or the like is used, if the spring load is reduced due to the deterioration of the C-type ring, the sliding resistance is also reduced. In contrast, in the tensioner 10 according to the first embodiment of the present disclosure, the coil spring 50 is used to generate the sliding resistance force Ps. The coil spring 50 is longer in the axial direction than the C-shaped ring and has a low spring constant, so that the load is hardly reduced. For this reason, the sliding resistance Ps obtained is not easily changed. Thereby, the tensioner 10 can exhibit the stable buffer performance. Furthermore, since the tensioner 10 does not require small parts such as a C-shaped ring in order to obtain buffer performance, maintenance is easy.

In the tensioner 10, the inclination angle of the inclined surface 44AE in the wedge portion 44A of the floating member 40 is equal to the inclination angle of the inclined surface 24A formed in the guide groove 24 of the housing 20, and is an angle θ1. This angle θ1 is set to be twice or more the friction angle. In the tensioner 10, the floating member 40 and the housing 20 are made of steel (static friction coefficient μ = about 0.12). In this case, the friction angle ρ = tan ⁻¹ μ = 6.8 ° is calculated. Therefore, θ1> 13.6 °. By setting the inclination angle θ1 of the inclined surface 44AE to be twice or more the friction angle, it is difficult for the floating member 40 to enter the insertion hole 22 as compared with a case where the inclination angle is smaller than twice, so that the plunger 30 is not pushed excessively. It is possible to suppress the pressure from acting and inhibiting the propulsion of the plunger 30.

The angle θ1 is preferably 30 ° or more and 60 ° or less. By doing so, the wedge portion 44A is inclined even when the biasing force of the coil spring 50 and the force in the direction of pushing the plunger 30 back to the inside of the housing 20 are larger than when the angle θ1 is smaller than 30 °. It is difficult to move inward in the axial direction of the housing 20 while in contact with the surface 24A. For this reason, it is easy to obtain the driving force of the plunger 30. Further, as compared with the case where θ1 is larger than 60 °, the wedge portion 44A is easily moved inward in the axial direction of the housing 20 while being in contact with the inclined surface 24A even if the biasing force of the coil spring 50 is small. For this reason, it is easy to obtain a pressing force against the plunger 30.

In the tensioner 10, the inclined angles θ 1 are formed equally so that the inclined surface 44 AE of the wedge portion 44 A of the floating member 40 and the inclined surface 24 A formed in the guide groove 24 of the housing 20 are in surface contact. However, embodiments of the present disclosure are not limited to this. For example, the inclination angle θ1 of the inclined surface 44AE of the wedge portion 44A may be larger or smaller than the inclined surface 24A of the housing 20.

For example, as shown in FIG. 9, a stepped cutout 24B may be formed in the guide groove 24 instead of the inclined surface 24A. A pressing force Pe can be obtained by the wedge portion 44A of the floating member 40 entering the cutout portion 24B. Note that the notch 24B is an example of an enlarged diameter portion in the present disclosure.

Furthermore, although the notch 24B is formed in a single stepped shape, the enlarged diameter portion may be a notched portion formed in a plurality of steps. By forming the cutout portion in a plurality of stages, the pressing force against the plunger 30 can be obtained stepwise.

Furthermore, the enlarged diameter portion may have a curved surface shape that follows a circular or elliptical arc. By adopting the curved surface shape, the boundary portion between the enlarged diameter portion and the portion other than the enlarged diameter portion in the guide groove 24 can be formed into a gentle shape. Thereby, abrasion resistance can be made high.

For example, as shown in FIG. 10, the floating member 40 may be formed with a protruding portion 44C protruding in an arc shape instead of the wedge portion 44A. The protruding portion 44C enters the inclined surface 24A of the guide groove 24, whereby the pressing force Pf can be obtained. Further, the arcuate protruding portion 44C may be used in combination with the above-described cutout portion 24B, a plurality of cutout portions, or a curved cutout portion.

Moreover, in this embodiment, although the inclined surface 24A is formed in the outer edge part of the guide groove 24 in the housing 20, and the peripheral part of the entrance / exit of the plunger 30, embodiment of this indication is not restricted to this. . For example, the inclined surface 24 A can be formed at any location on the inner side of the guide groove 24 from the entrance / exit of the plunger 30. In this case, the inclined surface 24 A is formed at a position different from the peripheral edge of the entrance / exit of the plunger 30. Further, the inclined surface 44AE of the plunger 30 is formed at a position in contact with the inclined surface 24A.

(housing)
As illustrated in FIGS. 3A and 3B, the housing 20 as an example of a holding member in the present disclosure is a bottomed cylindrical member. The housing 29 includes a substantially circular insertion hole 22, a guide groove 24 formed in the upper part of the insertion hole 22 along the insertion hole 22, and a guide groove 26 formed in the lower part of the insertion hole 22. Yes. An inclined surface 24A that is inclined in a direction away from the central axis CL of the insertion hole 22 from the inner side toward the outer side is formed at an outer end portion of the guide groove 24 (that is, a peripheral edge portion of an entrance / exit of the plunger 30 described later). The inclination angle of the inclined surface 24A is an angle θ1 with respect to the central axis CL.

[Second Embodiment]
The tensioner 70 of 2nd Embodiment is demonstrated. In the tensioner 70, the same components as those of the tensioner 10 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 11, the tensioner 70 of the second embodiment is different from the tensioner 10 of the first embodiment in the shape of the wedge portion 44 A in the floating member 40. In the tensioner 70, a recess 44D is formed on the surface of the wedge portion 44A that faces the plunger 30.

In the recess 44D, the wall portion 44E is formed in parallel with the inclined surface 44AE of the wedge portion 44A and the inclined surface 24A of the guide groove 24. Furthermore, a substantially triangular engagement member 72 is attached to the recess 44D in a cross-sectional view. The engagement member 72 is an example of a movement suppressing unit in the present disclosure. A coil spring 74 is attached between the outer peripheral surface (end surface facing outward) 72A of the engaging member 72 and the inner peripheral surface (end surface facing inward) 44F of the recess 44D. The coil spring 74 urges the engaging member 72 inward.

The surface of the engaging member 72 that faces the plunger 30 is provided with a concavo-convex portion 72B that is cut into gears. In addition, the surface of the plunger 30 that faces the engaging member 72 is also provided with a concavo-convex portion 30B that has been gear cut. The concavo-convex portion 72B of the engaging member 72 and the concavo-convex portion 30B of the plunger 30 are formed into shapes that engage with each other.

According to the tensioner 70 of the second embodiment, the uneven portion 30B of the plunger 30 is engaged with the uneven portion 72B of the engaging member 72. For this reason, when the plunger 30 pushes outward, the engaging member 72 also moves outward. On the other hand, the engaging member 72 is biased inward by a coil spring 74. For this reason, the engagement between the concavo-convex portion 72B of the engaging member 72 and the concavo-convex portion 30B of the plunger 30 is once released, and the engaging member 72 moves inward until it abuts against the wall portion 44E. And the uneven | corrugated | grooved part 72B of the engaging member 72 and the uneven | corrugated | grooved part 30B of the plunger 30 of the state propelled outside engage again.

Here, since the concavo-convex portion 30B of the plunger 30 is engaged with the concavo-convex portion 72B of the engaging member 72, when the plunger 30 attempts to retract inward, the engaging member 72 also moves inward. At this time, the engaging member 72 receives the pressing force Pc from the wall portion 44E. This pressing force Pc is transmitted by the engaging member 72 and presses the plunger 30 with the pressing force Pd. Thereby, the uneven part 72B of the engaging member 72 and the uneven part 30B of the plunger 30 are firmly engaged. For this reason, the movement to the inner side of the plunger 30 is suppressed. As a result, the tensioner 70 can continue to apply tension to the timing chain 106 even when it receives a strong pressing force from the chain guide 110 (see FIG. 6 and the like).

In addition, in this embodiment, although the uneven | corrugated | grooved part 72B is provided in the engaging member 72, embodiment of this indication is not restricted to this. For example, the concave portion 44D may not be formed in the wedge portion 44A, and the engaging member 72 may be omitted, and the concave and convex portion may be provided directly on the surface of the wedge portion 44A that faces the plunger 30. In this way, the number of parts can be reduced.

[Third Embodiment]
In the tensioner 80 of the third embodiment, as shown in FIG. 12A, a rod-shaped rotating member 84 is disposed inside the insertion hole 82 A in the housing 82. A torsion spring 85 surrounding the rotating member 84 is disposed around the rotating member 84 in a wound state. One end 85 A of the torsion spring 85 is fixed to the housing 82, and the other end 85 B is fixed to the rotating member 84. Thereby, rotational torque is applied to the rotating member 84.

In the rotating member 84, a male screw 84A is formed on the outer side of the portion where the torsion spring 85 is fixed. A female screw 86A formed inside the plunger 86 is engaged with the male screw 84A.

As shown in FIG. 12B, the plunger 86 has a two-sided shape when viewed from the axial direction of the housing 82. Further, a plate-like rotation restraining member 88 is fixed to the opening end of the insertion hole 82A in the housing 82. The rotation suppression member 88 includes a through hole 88 A that substantially matches the outer shape of the plunger 86. The plunger 86 is restricted from rotating by being inserted through the through hole 88A.

Thereby, the plunger 86 does not rotate even when the rotational torque of the rotating member 84 shown in FIG. 12A is applied, and is given a biasing force for propelling to the outside of the insertion hole 82A.

The housing 82 has a guide groove 82B and an inclined portion 82C. The guide groove 82B and the inclined portion 82C have the same configuration as the guide groove 24 and the inclined surface 24A in the housing 20 of the first embodiment. The sliding portion 90A of the floating member 90 is disposed in the guide groove 82B. A bottom portion 90B through which the rotating member 84 is inserted is formed at the inner end of the sliding portion 90A. In addition, an inclined portion 90C whose diameter increases toward the outside is formed at the outer end of the sliding portion 90A.

A coil spring 92 is disposed between the plunger 86 and the bottom 90B of the floating member 90. The coil spring 92 biases the plunger 86 outward and biases the floating member 90 inward.

According to the tensioner 80 of the third embodiment, the driving force to the outside of the plunger 86 is obtained from the torsion spring 85 and the coil spring 92. On the other hand, the inward biasing force of the floating member 90 is obtained only from the coil spring 92. Thereby, for example, by increasing the rotational torque of the torsion spring 85 relative to the urging force of the coil spring 92, the pressing force against the chain guide 110 (see FIG. 6 and the like) is increased, while the floating member 90 The sliding resistance received can be reduced. Alternatively, for example, when the urging force of the coil spring 92 is relatively increased with respect to the rotational torque of the torsion spring 85, the sliding resistance force received from the floating member 90 can be relatively increased.

Thus, according to the tensioner 80, the magnitude relationship between the pressing force of the plunger 86 against the chain guide 110 and the sliding resistance force received by the plunger 86 from the floating member 90 can be arbitrarily set. That is, fine control over the flickering of the timing chain 106 can be performed.

In addition, the torsion spring 85 in the third embodiment biases the plunger 86 outward. For this reason, the plunger 86 is restrained from moving inward. That is, the torsion spring 85 is an example of a movement suppressing unit in the present disclosure. As a movement restraining means for restraining the plunger 86 from moving inward, an oil damper, a ratchet mechanism, or the like may be used as appropriate in addition to the above-described engaging member 72 and torsion spring 85.

[Fourth Embodiment]
As shown in FIG. 13, the tensioner 120 according to the fourth embodiment includes a housing 112, a plunger 114, a floating member 116, and a coil spring 118.

The housing 112 is obtained by omitting the flange 28 in the housing 20 of the first embodiment shown in FIG. 2A. Moreover, the plunger 114 forms the external thread 114A in the outer end part in the plunger 30 of 1st Embodiment. The tensioner 120 is fixed to the engine 100 by the male screw 114 A being screwed into the female screw 100 A formed in the engine 100.

In the tensioner 120 of the fourth embodiment, the housing 112 is driven by the biasing force of the coil spring 118. For this reason, the chain guide 110 (see FIG. 6 and the like) is pressed at the tip of the housing 112. The buffer effect obtained by the tensioner 120 is the same as the buffer effect obtained by the tensioner 10 of the first embodiment, and detailed description thereof is omitted. As described above, the tensioner according to the present disclosure can be implemented in various modes.

The entire disclosure of Japanese Patent Application No. 2018-054023 filed on Mar. 22, 2018 is incorporated herein by reference. All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.

Claims

A cylindrical holding member;
An idler member slidably attached to the holding member in the axial direction;
A propulsion member mounted on the floating member so as to be relatively movable;
An urging member that is provided between the floating member and the propelling member, urges the propelling member toward the axially outer side of the holding member, and urges the floating member toward the axially inner side of the holding member;
Formed in a state of contact between the floating member and the holding member, and when the propelling member moves, the propelling member and the holding member are pressed by pressing the floating member in a direction intersecting the axial direction. Sliding force increasing means for increasing the sliding resistance of
Tensioner with
The sliding force increasing means is
A diameter-enlarged portion formed on the inner peripheral surface of the holding member and expanding from the inner side in the axial direction to the outer side in the axial direction of the holding member;
A wedge part formed on the floating member and in contact with the enlarged diameter part;
The tensioner of claim 1 having
At least one of the enlarged diameter portion and the wedge portion in contact with the enlarged diameter portion is formed with an inclined surface that gradually changes in diameter from the inner side in the axial direction to the outer side in the axial direction of the holding member. The tensioner according to claim 2.
The tensioner according to claim 3, wherein the inclined surface is formed on both the enlarged diameter portion and the wedge portion in contact with the enlarged diameter portion.
The tensioner according to claim 3 or 4, wherein an inclination angle of the inclined surface is 30 ° or more and 60 ° or less with respect to an axial direction of the holding member.
The tensioner according to any one of claims 2 to 5, further comprising movement restraining means for restraining the propulsion member from moving to the inside of the holding member.
The tensioner according to claim 6, wherein the movement restraining means is a concavo-convex part that is provided on a contact surface between the wedge part and the propelling member and engages with each other.