JPWO2019181690A1 - Tensioner - Google Patents

Abstract

The tensioner is between a tubular holding member, a floating member slidably mounted on the holding member in the axial direction, a propulsion member mounted on the floating member so as to be relatively movable, and between the floating member and the propulsion member. It is formed in a state where the propulsion member is urged outward in the axial direction of the holding member and the floating member is urged inward in the axial direction of the holding member, and the floating member is in contact with the holding member. When the propulsion member moves, the floating member is pressed in a direction intersecting the axial direction to increase the sliding resistance between the propulsion member and the holding member.

Description

This disclosure relates to tensioners.

Japanese Unexamined Patent Publication No. 2005-344877 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 accommodating hole of the housing body. An annular groove is formed on the outer circumference of the cylindrical plunger, and a C-shaped ring is fitted into the annular groove. Further, the C-shaped ring is urged to increase in diameter toward the inner peripheral wall of the plunger accommodating hole. As a result, for example, even if a shocking load acts on the columnar plunger from the timing chain when the engine is started, the C-shaped ring exhibits cushioning performance, and the rapid backward movement of the columnar plunger is suppressed.

In the ring type hydraulic tensioner of Japanese Patent Application Laid-Open No. 2005-344877, the C-shaped ring slides with the inner peripheral wall of the plunger accommodating hole as the plunger moves back and forth. Due to this sliding friction, the inner peripheral wall of the plunger accommodating hole is worn. As a result, the gap between the inner peripheral wall of the plunger accommodating hole and the outer peripheral surface of the plunger increases. In addition, wear and heat settling of the C-shaped ring occur, and the diameter-expanding force of the C-shaped ring decreases. In these cases, the cushioning performance of the C-shaped ring may decrease.

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

The tensioner of the first aspect includes a tubular holding member, a floating member slidably mounted on the holding member in the axial direction, a propulsion member mounted on the floating member so as to be relatively movable, and the floating member. An urging member provided between the force and the propulsion member, the propulsion member being urged outward in the axial direction of the holding member, and the floating member being urged inward in the axial direction of the holding member, and the floating member. It is formed in a state of being in contact with the holding member, and when the propulsion member moves, the floating member is pressed in a direction intersecting the axial direction, and the propulsion member and the holding member slide. It has a sliding force increasing means for increasing resistance.

In the tensioner of 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 due to the urging force of the urging member. At this time, the sliding force increasing means formed in contact between the floating member and the holding member presses the propulsion member together with the floating member in the direction intersecting the axial direction. Therefore, the sliding resistance between the propulsion member and the holding member increases. As a result, the sliding speed of the propulsion member becomes slow, and the cushioning function is exhibited.

Further, when a force in the 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 together with the floating member in the axial direction of the holding member against the urging force of the urging member. .. At this time as well, since the floating member moves inward in the axial direction of the holding member, the sliding force increasing means presses the propulsion member together with the floating member in the direction intersecting the axial direction. Therefore, the sliding resistance between the propulsion member and the holding member increases. As a result, the sliding speed of the propulsion member becomes slow, and the cushioning function is exhibited.

As described above, in the tensioner of the first aspect, the urging member, the floating member, the holding member and the sliding force increasing means are interrelated to exhibit the cushioning performance. Therefore, it is difficult for the load to concentrate on a specific member, and the cushioning performance is unlikely to deteriorate.

On the other hand, for example, when a C-shaped ring or the like is arranged around the propulsion member and the cushioning performance is exerted by the spring load of the C-shaped ring, the cushioning performance depends only on the C-shaped ring. Therefore, if the C-shaped ring is physically deteriorated, the cushioning performance tends to be deteriorated.

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

In the tensioner of the second aspect, a diameter-expanded portion is formed on the inner peripheral surface of the holding member. The diameter-expanded portion expands in diameter from the inside in the axial direction of the holding member to the outside in the axial direction toward the outside in the radial direction of the holding member. When the floating member moves inward in the axial direction of the holding member due to 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 intersecting the axial direction of the holding member. As a result, the sliding resistance between the propulsion member and the holding member increases.

The tensioner of the third aspect has a gradual diameter of at least one of the enlarged diameter portion and the wedge portion in contact with the enlarged diameter portion toward the radial outer side of the holding member from the axial inner side to the axial outer side of the holding member. A changing slope is formed.

In the tensioner of the third aspect, an inclined surface whose diameter gradually changes is formed in the enlarged diameter portion or the wedge portion. Therefore, when the floating member moves inward in the axial direction due to the urging force of the urging member, the pressing force from the enlarged diameter portion to the wedge portion gradually increases. As a result, smooth cushioning 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 of 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. Therefore, it is easy to obtain cushioning performance.

In the tensioner of 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 as compared with the case where it is larger than 60 °. Is easy to move inward in the axial direction of the holding member while being 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 propulsion member are pushed back to the inside of the holding member as compared with the case where the inclination angle is smaller than 30 °. Even if the force in the direction 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 of the sixth aspect includes a movement suppressing means for suppressing the movement of the propulsion member inward in the axial direction.

According to the tensioner of the sixth aspect, the movement suppressing means suppresses the movement of the propulsion member to the inside of the holding member. Therefore, even when the propulsion member is strongly pressed inward, it is possible to prevent the propulsion member from moving inward. This makes it possible to enhance the buffering effect.

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

According to the tensioner of the seventh aspect, an uneven portion that engages with each other is provided between the wedge portion of the floating member and the propulsion member. Therefore, when the wedge portion is pressed from the holding member, the uneven portions mesh with each other. As a result, it is possible to prevent the propulsion member from moving inward.

According to the tensioner according to the present disclosure, the cushioning performance for suppressing abrupt displacement of the propulsion member is unlikely to deteriorate.

It is an elevation view which shows the state which the tensioner which concerns on 1st Embodiment of this disclosure is fixed to an engine. It is sectional drawing which shows the state which the coil spring was contracted in the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the state which the coil spring was extended in the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the housing in the tensioner which concerns on 1st Embodiment of this disclosure. It is a front view which shows the housing in the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the plunger in the tensioner which concerns on 1st Embodiment of this disclosure. It is a front view which shows the plunger in the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the floating member in the tensioner which concerns on 1st Embodiment of this disclosure. It is a front view which shows the floating member in the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which showed the state which the tensioner which concerns on 1st Embodiment of this disclosure presses a chain guide. It is sectional drawing which showed the state which the tensioner which concerns on 1st Embodiment of this disclosure presses a chain guide, and is further pressed from a chain guide. It is a graph which shows the stroke characteristic of the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the modification which cutout | cut out the guide groove of the housing in the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the modification which formed the protruding part in the floating member in the tensioner which concerns on 1st Embodiment of this disclosure. It is sectional drawing which shows the tensioner which concerns on 2nd Embodiment of this disclosure. It is sectional drawing which shows the tensioner which concerns on 3rd Embodiment of this disclosure. It is a front view which shows the tensioner which concerns on 3rd Embodiment of this disclosure. It is sectional drawing which shows the tensioner which concerns on 4th Embodiment of this disclosure.

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

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 in the housing 20. Then, the plunger 30 urged in the direction away from the housing 20 presses the chain guide 110 rotating about the support shaft 108 with the propulsive force P. Further, the chain guide 110 presses the timing chain 106.

As shown in FIGS. 2A and 2B, the tensioner 10 is arranged 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. It includes a floating member 40.

(housing)
As shown in FIGS. 3A and 3B, the housing 20 as an example of the holding member in the present disclosure is a bottomed tubular 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 24A is formed from the inside to the outside of the insertion hole 22 at the outer end of the guide groove 24 (that is, the peripheral edge of the entrance / exit of the plunger 30 described later). The inclined surface 24A gradually changes in diameter in the direction away from the central axis CL of the insertion hole 22 (in other words, the inclined surface 24A gradually inclines toward the inside in the radial direction of the housing 20 from the outside to the inside). The inclination angle of the inclined surface 24A is an angle θ1 with respect to the central axis CL. The inclined surface 24A is an example of the enlarged diameter portion in the present disclosure.

The above-mentioned "upper part" and "lower part" indicate the direction on the paper surface of FIG. 3, and do not indicate the direction in the state of being attached to the engine 100 shown in FIG. Further, "inside" indicates the hole bottom 22A side of the insertion hole 22 (inward in the axial direction, arrow IN side in FIG. 3A), and "outside" means the opening end 22B side of the insertion hole 22 (outside in the axial direction, FIG. The arrow OUT side in 3A) is shown. The same applies to "upper part", "lower part", "inner side" and "outer side" used in the following description.

Flange 28s through which the bolt holes 28A pass are formed in the upper portion and the lower portion of the housing 20. As shown in FIG. 1, the flange 28 is fixed to the engine 100 by using a bolt 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 the presser screw 52 into the screw hole 29, the 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 propulsion member in the present disclosure is a bottomed tubular 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 32B side of the insertion hole 32 and projects outward in the radial direction of the insertion hole 32. As shown in FIG. 2A, in the plunger 30, the opening end 32B of the insertion hole 32 faces the inside of the insertion hole 22 of the housing 20, and the guide protrusion 34 is fitted into 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 size that does not cause any trouble when it is inserted into the insertion hole 22 of the housing 20, and is a size 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 circular bottom portion 42 and the outer peripheral end of the bottom portion 42 to the bottom portion 42. The sliding portion 44 is provided.

In the sliding portion 44, a wedge portion 44A is formed at an end opposite to the bottom portion 42. The wedge portion 44A is formed to be thicker than the other portions of the sliding portion 44, and is an inclined surface 44AE 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 of the sliding portion 44 with respect to the extending direction) is equal to the inclination angle of the inclined surface 24A formed in the guide groove 24 of the housing 20 described above, 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 portion 42 is arranged inside the plunger 30 and the sliding portion 44 is fitted into the guide groove 24 of the housing 20. Will be done. Further, in the floating member 40, the outer end portion of the sliding portion 44 projects to the outside of the housing 20 (guide groove 24), and the inclined surface 44AE of the wedge portion 44A comes into contact with the inclined surface 24A of the guide groove 24. It is arranged inside the insertion hole 22. At this time, the wedge portion 44A is arranged on the radial inside of the insertion hole 22 in the housing 20 and on the axial outside of the insertion hole 22 with respect to the inclined surface 24A. The wedge portion 44A and the inclined surface 24A of the guide groove 24 are examples of the sliding force increasing means 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 gap (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 for urging the plunger 30 to the outside and urging the floating member 40 to the inside is arranged between the plunger 30 and the bottom portion 42 of the floating member 40. The coil spring 50 is an example of the urging member in the present disclosure, and is inserted into the insertion hole 32 of the plunger 30. The coil spring 50 is arranged between the bottom 32A of the insertion hole 32 and the bottom 42 of the floating member 40 in a state of being 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 urging 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 tip of the guide groove 26. When the guide protrusion 34 comes into contact with the retaining member 60, the movement of the plunger 30 is stopped.

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

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

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

Here, assuming that the coefficient of friction between the floating member 40 and the plunger 30 and the coefficient of friction between the plunger 30 and the housing 20 are both μ, the plunger 30 has a sliding resistance force Ps = from each of the floating member 40 and the housing 20. Receive (2 x Pa x μ). As a result, 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 acts on the timing chain 106 as the cam torque fluctuates. Then, as shown in FIG. 7, the plunger 30 receives the pressing force P2 from the chain guide 110. This pressing force P2 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 that the wedge portion 44A of the floating member 40 presses against the inclined surface 24A of the housing 20 becomes larger. Therefore, 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 the above-mentioned reactions, respectively. It becomes larger than the force Pb, the pressing force Pa, and the sliding resistance force Ps. Therefore, the propulsion load PF2 = (P1-PS) on which the plunger 30 presses the chain guide 110 is smaller than the propulsion load PF1 = (P1-Ps).

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

As shown in FIG. 8, with respect to the propulsion load PF1 = (P1-Ps) that presses the chain guide 110 when the plunger 30 is propelled (that is, when it moves to the outside of the insertion hole 22), it is retracted (that is, the insertion hole). The backward load PF3 = (P1 + PS) on the “necessary” plunger 30 (when moving inward of 22) is larger by the total value (Ps + PS) of the sliding resistance forces Ps and 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 of the first embodiment uses the floating member 40, the sudden propulsion of the plunger 30 is suppressed when the plunger 30 is propelled, as compared with the case where the coil spring 50 is used alone. Further, the tensioner 10 slowly presses the chain guide 110 to suppress the fluttering of the timing chain 106. Further, when the engine 100 is driven and the fluttering of the timing chain 106 becomes large, the tensioner 10 exerts a large resistance force to suppress the retreat of the plunger 30 and suppress the fluttering.

Further, the tensioner 10 presses the chain guide 110 with a smaller propulsive force as compared with the case where the coil spring 50 is used alone. Therefore, the sliding friction between the chain guide 110 and the timing chain 106 can be reduced. As a result, the occurrence of mechanical loss can be suppressed.

Further, in the tensioner 10, the outer diameter of the plunger 30 is set to have a size substantially matching the inner diameter of the insertion hole 22. Further, the inner peripheral surface 44B of the floating member 40 is in surface contact with the outer peripheral surface 30A of the plunger 30. Therefore, the pressing force Pa acts surfacely on the plunger 30. Therefore, the plunger 30 is less likely to be worn, and the cushioning performance of the tensioner 10 is less likely to be deteriorated.

Further, in the tensioner 10, the wedge portion 44A of the floating member 40 presses the inclined surface 24A formed in the guide groove 24 of the housing 20. As a result, a sliding resistance force acts on the plunger 30. When the wedge portion 44A is worn as an inclined surface 44AE as shown by a broken line in FIG. 2, the floating member 40 is arranged inside the insertion hole 22 by the amount of wear as shown by an arrow M. Therefore, it is difficult for the sliding resistance to be reduced due to wear. The same applies when the inclined surface 24A is worn.

Further, in the tensioner 10, a strong sliding resistance PS is generated when the plunger 30 is retracted. The sliding resistance force PS changes depending on the pressing force P2 that the plunger 30 receives from the chain guide 110. That is, the larger the pressing force P2, the larger the sliding resistance force PS. Therefore, a high sliding resistance force 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 and, for example, a C-shaped ring or the like urged to increase the diameter is arranged between the outer peripheral surface 30A of the plunger 30 and the inner peripheral surface 22C of the insertion hole 22. (When the configuration is different from the present disclosure), it is possible to obtain a sliding resistance force of "a certain size", but it is difficult to obtain a sliding resistance force corresponding to the size of the pressing force P2.

Further, when a C-type ring or the like is used, if the spring load decreases as the C-type ring deteriorates, the sliding resistance force also decreases. On the other hand, 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 has a longer axial length and a lower spring constant than the C-shaped ring, so that the load is unlikely to decrease. Therefore, the obtained sliding resistance force Ps is also unlikely to fluctuate. As a result, the tensioner 10 can exhibit stable buffering performance. Further, the tensioner 10 does not require a small component such as a C-shaped ring in order to obtain cushioning performance, so 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 at least twice 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), and 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 twice or more the friction angle, it is difficult for the floating member 40 to enter the inside of the insertion hole 22 as compared with the case where it is smaller than twice, so that the plunger 30 is pushed excessively. It is possible to suppress the action of pressure from hindering 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 if the urging force of the coil spring 50 or the force in the direction of pushing the plunger 30 back to the inside of the housing 20 is larger than that when the angle θ1 is smaller than 30 °. It is difficult to move inward in the axial direction of the housing 20 while being in contact with the surface 24A. Therefore, 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 more likely to move inward in the axial direction of the housing 20 while being in contact with the inclined surface 24A even if the urging force of the coil spring 50 is small. Therefore, it is easy to obtain a pressing force on the plunger 30.

In the tensioner 10, each inclination angle θ1 is formed equally so that the inclined surface 44AE of the wedge portion 44A of the floating member 40 and the inclined surface 24A formed in the guide groove 24 of the housing 20 are in surface contact with each other. However, the 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.

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

Further, although the notch portion 24B is formed in a one-step shape, the diameter-expanded portion may be a notch portion formed in a plurality of steps. By forming the notch portions in a plurality of stages, the pressing force on the plunger 30 can be obtained stepwise.

Furthermore, the enlarged diameter portion may have a curved surface shape that follows the arc of a circle or an ellipse. By forming 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. As a result, wear resistance can be increased.

Further, 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 pressing force Pf can be obtained by the protruding portion 44C entering the inclined surface 24A of the guide groove 24. Further, the arc-shaped protrusion 44C may be used in combination with the above-mentioned notch 24B, a plurality of steps of the notch, and a curved notch.

Further, in the present embodiment, the inclined surface 24A is formed at the outer end of the guide groove 24 in the housing 20 and at the peripheral edge of the entrance / exit of the plunger 30, but the embodiment of the present disclosure is not limited to this. .. For example, the inclined surface 24A can be formed at an arbitrary position inside the entrance / exit of the plunger 30 in the guide groove 24. In this case, the inclined surface 24A is formed at a position different from the peripheral edge of the entrance / exit of the plunger 30. Further, the inclined surface 44AE in the plunger 30 is formed at a position in contact with the inclined surface 24A.

(housing)
As shown in FIGS. 3A and 3B, the housing 20 as an example of the holding member in the present disclosure is a bottomed tubular 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. There is. At the outer end of the guide groove 24 (that is, the peripheral edge of the entrance / exit of the plunger 30 described later), an inclined surface 24A inclined in a direction away from the central axis CL of the insertion hole 22 is formed from the inside to the outside. 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 the second embodiment will be described. The configuration of the tensioner 70 that is the same as that of the tensioner 10 of the first embodiment is indicated by the same reference numerals, and description thereof will be omitted. As shown in FIG. 11, in the tensioner 70 of the second embodiment, the shape of the wedge portion 44A in the floating member 40 is different from that of the tensioner 10 of the first embodiment. In the tensioner 70, a recess 44D is formed on the surface of the wedge portion 44A facing 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. Further, an engaging member 72 having a substantially triangular shape in cross section is attached to the recess 44D. The engaging member 72 is an example of the movement suppressing means 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.

A tooth-cut uneven portion 72B is provided on the surface of the engaging member 72 facing the plunger 30. Further, a tooth-cut uneven portion 30B is also provided on the surface of the plunger 30 facing the engaging member 72. The concavo-convex portion 72B of the engaging member 72 and the concavo-convex portion 30B of the plunger 30 are formed in a shape that engages 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. Therefore, when the plunger 30 is propelled outward, the engaging member 72 also moves outward. On the other hand, the engaging member 72 is urged inward by the coil spring 74. Therefore, the engagement between the uneven portion 72B of the engaging member 72 and the uneven portion 30B of the plunger 30 is temporarily released, and the engaging member 72 moves inward until it comes into contact with the wall portion 44E. Then, the concave-convex portion 72B of the engaging member 72 and the concave-convex portion 30B of the plunger 30 propelled outward are engaged again.

Here, since the uneven portion 30B of the plunger 30 is engaged with the uneven portion 72B of the engaging member 72, when the plunger 30 tries to regress 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 the plunger 30 is pressed by the pressing force Pd. As a result, the uneven portion 72B of the engaging member 72 and the uneven portion 30B of the plunger 30 are firmly engaged. Therefore, the movement of the plunger 30 inward is suppressed. As a result, the tensioner 70 can continue to apply tension to the timing chain 106 even if it receives a strong pressing force from the chain guide 110 (see FIG. 6 and the like).

In the present embodiment, the engaging member 72 is provided with the uneven portion 72B, but the embodiment of the present disclosure is not limited to this. For example, the engaging member 72 may be omitted without forming the concave portion 44D in the wedge portion 44A, and the concave-convex portion may be provided directly on the surface of the wedge portion 44A facing the plunger 30. By doing so, 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 arranged inside the insertion hole 82A in the housing 82. A torsion spring 85 surrounding the rotating member 84 is arranged around the rotating member 84 in a wound state. One end 85A of the torsion spring 85 is fixed to the housing 82, and the other end 85B is fixed to the rotating member 84. As a result, rotational torque is applied to the rotating member 84.

In the rotating member 84, a male screw 84A is formed on a portion outside 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-chamfered outer shape when viewed from the axial direction of the housing 82. A plate-shaped rotation restraining member 88 is fixed to the open end of the insertion hole 82A in the housing 82. The rotation restraining member 88 includes a through hole 88A that substantially matches the outer shape of the plunger 86. The rotation of the plunger 86 is restricted by inserting the through hole 88A.

As a result, the plunger 86 does not rotate even when the rotational torque of the rotating member 84 shown in FIG. 12A is applied, and an urging force is given to propel the plunger 86 to the outside of the insertion hole 82A.

Further, the housing 82 is formed with 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. A sliding portion 90A of the floating member 90 is arranged in the guide groove 82B. At the inner end of the sliding portion 90A, a bottom portion 90B through which the rotating member 84 is inserted is formed. Further, an inclined portion 90C whose diameter increases toward the outside is formed at the outer end portion of the sliding portion 90A.

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

According to the tensioner 80 of the third embodiment, the outward propulsion force of the plunger 86 is obtained from the torsion spring 85 and the coil spring 92. On the other hand, the inward urging force of the floating member 90 is obtained only from the coil spring 92. As a result, for example, the rotational torque of the torsion spring 85 is increased relative to the urging force of the coil spring 92, thereby increasing the pressing force on the chain guide 110 (see FIG. 6 and the like), while increasing the pressing force from the floating member 90. The sliding resistance force received can be reduced. Alternatively, for example, if the urging force of the coil spring 92 is made relatively large with respect to the rotational torque of the torsion spring 85, the sliding resistance force received from the floating member 90 can be made relatively large.

As described above, according to the tensioner 80, the magnitude relationship between the pressing force of the plunger 86 on 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 fluttering of the timing chain 106 can be performed.

The torsion spring 85 in the third embodiment urges the plunger 86 to the outside. Therefore, the plunger 86 is suppressed from moving inward. That is, the torsion spring 85 is an example of the movement suppressing means in the present disclosure. As the movement suppressing means for suppressing the movement of the plunger 86 inward, in addition to the above-mentioned engaging member 72 and the torsion spring 85, an oil damper, a ratchet mechanism, or the like may be appropriately used.

[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 the one in which the flange 28 in the housing 20 of the first embodiment shown in FIG. 2A is omitted. Further, the plunger 114 has a male screw 114A formed at the outer end portion of the plunger 30 of the first embodiment. The tensioner 120 is fixed to the engine 100 by screwing the male screw 114A into the female screw 100A formed on the engine 100.

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

The disclosure of Japanese Patent Application No. 2018-054023, filed March 22, 2018, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated herein by reference.

Claims (7)

Cylindrical holding member and
A floating member mounted on the holding member so as to be slidable in the axial direction,
A propulsion member mounted on the floating member so as to be relatively movable,
An urging member provided between the floating member and the propulsion member, the propulsion member being urged outward in the axial direction of the holding member, and the floating member being urged inward in the axial direction of the holding member.
It is formed in a state of being in contact with the floating member and the holding member, and when the propulsion member moves, the floating member is pressed in a direction intersecting the axial direction to cause the propulsion member and the holding member. A means for increasing the sliding force to increase the sliding resistance of the
Tensioner with. The sliding force increasing means is
A diameter-expanded portion formed on the inner peripheral surface of the holding member and expanding in diameter from the inner side in the axial direction to the outer side in the axial direction of the holding member.
A wedge portion formed on the floating member and in contact with the enlarged diameter portion,
The tensioner according to claim 1. 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 whose diameter gradually changes toward the radial outer side of the holding member from the axial inner side to the axial outer side 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 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. The tensioner according to any one of claims 2 to 5, further comprising a movement suppressing means for suppressing the movement of the propulsion member to the inside of the holding member. The tensioner according to claim 6, wherein the movement suppressing means is an uneven portion that is provided on the contact surface between the wedge portion and the propulsion member and engages with each other.

Images