Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/08—Means for varying tension of belts, ropes or chains 
  • F16H7/0829—Means for varying tension of belts, ropes or chains  with vibration damping means
  • F16H7/0836—Means for varying tension of belts, ropes or chains  with vibration damping means of the fluid and restriction type, e.g. dashpot
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/08—Means for varying tension of belts, ropes or chains 
  • F16H2007/0802—Actuators for final output members
  • F16H2007/0808—Extension coil springs
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/08—Means for varying tension of belts, ropes or chains 
  • F16H7/0848—Means for varying tension of belts, ropes or chains  with means for impeding reverse motion
  • F16H2007/0853—Ratchets
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/08—Means for varying tension of belts, ropes or chains 
  • F16H2007/0889—Path of movement of the finally actuated member
  • F16H2007/0891—Linear path

Definitions

• the invention relates to a tensioner with integrated non-return and lock.
• a hydraulic chain tensioner comprises a body defining an internal chamber intended to be filled with a hydraulic fluid and housing at least partially inside a piston sliding relative to the body and recessed projecting from the body by a spring.
• the inner chamber is connected to a source of hydraulic fluid under pressure.
• the hydraulic tensioner may include a non-return device.
• chain tensioners anti-return devices These frequently have a ratchet pivotally mounted on the body and provided with teeth meshing in a series of notches carried by the piston. These non-return devices are locked by a locking system of two types.
• the first type of locking system for a non-return device uses a pin or a locking pin that must be removed from the tensioner and discard.
• the second type of locking system for a non-return device uses a swivel hook that unlocks under the action of gravity.
• this tensioner can not be assembled in certain uses of the chain that it tends, for example in a warp motor architecture.
• this pin to be removed during assembly, can be lost accidentally before mounting thus no longer ensuring its locking role.
• such a locking pin system requires the use of at least one additional piece.
• US-A-4,822,320 discloses a ratchet type tensioner with a body and a sliding piston for maintaining the tension of a chain wrapped around wheels teeth, gears or pulleys.
• a series of notches carried by the piston meshes with a pawl which is pivotally connected to the body.
• the piston can not completely out or return, because in both cases the piston tilts the pawl abutting the side of a spring associated with the ratchet to recall it in a position.
• This pawl can block the piston for mounting in only one extreme position of the piston, here a fully extended piston position.
• the problem underlying the invention is to provide a hydraulic chain tensioner of a locking system of its piston associated with a non-return device of the piston, the locking system having no not the disadvantages of a pin unlocking system or hook system unlocking by gravity.
• a tensioner comprising a body housing at least partially in its interior a sliding piston relative to the body and called out of the body by first return means, the bearing body on an area of its periphery a pawl disposed on a pivot axis relative to the body and provided with a first non-return tooth providing a function of non-return of the piston in the body by meshing of this tooth in a notch a series of notches carried by the piston, downstream relative to the direction of exit of the piston, from the pivot axis and then by buttressing the pawl at this non-return tooth on the piston, characterized in that the pawl carries a locking tooth ensuring a locking function of the piston outlet relative to the body by meshing of this tooth in a notch of the series, upstream of the pivot axis, and jamming of the ratchet at the level of Dec this tooth on the piston.
• the pawl is associated with second return means arranged so as to rotate the pawl in the upstream direction relative to the direction of exit of the piston.
• the pawl bears a bearing zone, a pressure on this bearing zone making it possible to pivot the pawl in the downstream direction in order to facilitate the release of the non-return tooth and the establishment of the locking tooth.
• the pawl comprises a second non-return tooth adapted to engage in a notch carried by the piston, downstream of the pivot axis, this second tooth cooperating with the first tooth so as to offer a translation distance of the piston in the upstream direction greater than the inter-notch distance between a tilting of the pawl in a notch and the anti-return lock.
• the series of notches comprises a wall defining the upstream end of the series of notches higher than a notch, the spokes of the locking tooth and the non-return tooth and their angular spacing. being such that when the locking tooth abuts against the piston outside the series of notches, the piston is retained by the non-return tooth bearing on the end wall.
• the tensioner is a hydraulic tensioner for receiving a hydraulic fluid.
• the hydraulic fluid makes it possible to assist in maintaining the piston in its extended position.
• the invention also relates to a drive assembly by a closed belt or a closed chain, characterized in that it comprises a tensioner according to any one of the variants described above for the tensioning of the belt closed or closed chain.
• the invention also relates to a combustion engine characterized in that it comprises such a drive assembly.
• the invention also relates to a locking method of a tensioner of the invention by a user, characterized in that from an initial position in which the piston is held by a non-return tooth arranged on the pawl inserted into a notch of the series carried by the piston:
• the piston is unlocked by pressing on the piston in the upstream direction which allows to release the locking tooth of the notch in which it was inserted by rotating the ratchet in the upstream direction under the action of the second return means.
• FIG. 1 is a diagrammatic representation of a perspective and exploded view of a hydraulic tensioner comprising a locking system formed of a three-tooth ratchet according to the present invention
• FIGS. 9 and 9a are longitudinal sections respectively of a hydraulic tensioner and a pawl cooperating with a series of notches carried by the piston, Figures 2a to 10a being shown enlarged with respect to Figures 2 to 10, this in various locking and anti-return positions, and FIG. 9b is an enlarged sectional view of the contact of the third tooth of the pawl with a notch carried by the piston in the position of FIGS. 9 and 9a, the hydraulic tensioner and the ratchet in all these figures being in accordance with the present invention.
• FIGS. 9 and 9a the hydraulic tensioner and the ratchet in all these figures being in accordance with the present invention.
• the present invention relates to a hydraulic tensioner 1 which may be suitable for a closed-chain or closed-belt drive unit.
• the hydraulic tensioner 1 comprises a body 2 delimiting an internal chamber intended to be filled with a hydraulic fluid and housing at least partially inside a piston 3 sliding relative to the body 2 and called out protruding from the body 2 by first return means.
• the first return means may be in the form of a first spring 4.
• the piston 3 may comprise a blind internal recess, referenced 9 to the other figures, communicating with the internal chamber of the body 2 and at least partially housing the first spring 4.
• the body 2 bears on an area of its periphery a pawl 5 is mounted on a rigid axis 10 maintained by the body 2, the axis 10 acts as a pivot axis 6 relative to the body 2.
• the ratchet 5 ensures a function of non-return of the piston 3 in the body 2.
• the pawl 5 is also provided with a first and a second tooth 5a, 5b, here referred to as anti-return teeth, meshing in a series 7 of notches 7a carried by the piston 3 to limit the movement of the piston 3 relative to the body 2.
• the series 7 of notches 7a extends in the length of the piston 3, that is to say that the notches 7a follow each other in the length of the piston 3 at least over a limited portion of this length.
• first and second teeth 5a, 5b provide an anti-return function of the piston 3 in the body 2 which will be more fully described later. None of the two teeth 5a, 5b never holds the piston 3 in the direction of its exit. In this embodiment, the cooperation of the two teeth is used to perform a hysteresis at the pawl 5 between the inlet and the outlet of the piston 3.
• the pawl 5 carries a third tooth 5c, still designated locking tooth, intended to enter a notch 7a of the series 7 to ensure a locking of the piston 3 relative to the body 2 in a retracted position of the piston 3 in the body 2, that is to say prevent an exit movement of the piston 3 by the first return means 4.
• a locking function is associated with a non-return function on the same Ratchet member 5.
• the pivot axis 6 of the pawl 5 extends substantially perpendicular to the stroke of the piston 3.
• the pawl 5 is associated with second return means. These second return means are arranged so as to rotate the pawl 5 in the upstream direction, upstream and downstream being defined here relative to the direction of exit of the piston 3.
• the second return means may be in the form of a second spring 8 return.
• the second spring 8 of return can be housed in a groove in the body 2, one end of the second spring 8 being in abutment against the bottom of the groove while the other end of the second spring 8 is in abutment against the ratchet 5.
• Figures 2 to 4 and 2a to 4a while also referring to Figure 1, illustrate the non-return function present in the hydraulic tensioner. This function limits the movement of the piston 3 during the engine start phase, when the hydraulic tensioner 1 is not yet filled with the oil ensuring the damping function by limiting the movement and avoiding clatter-type inconveniences. and / or abnormal noises.
• Figures 2 and 2a taken in combination with Figure 1, illustrate a first position or tilting threshold.
• the pawl 5 rotates on its axis 6 under the effect of scrolling notches 7a of the piston 3 which are interposed with the teeth 5a, 5b of the pawl 5.
• the piston 3 and the pawl 5 occupy a position where their vertices of notches 7a and 5b teeth are aligned ( Figure 2a).
• the second return means 8 tends to rotate the pawl 5 in the upstream direction, that is to say the opposite direction of the output direction of the piston 3, an additional piston outlet 3 then causes a new insertion of the tooth 5b in a notch 7a, but this time with the notch N + 1 of the series 7 carried by the piston 3, the notch N being the notch previously engaged.
• Figures 3 and 3a taken in combination with Figure 1, illustrate a second position which is a non-return locking position.
• the teeth 5a, 5b are interposed in notches 7a, the fact of retracting the piston 3 causes a jamming of the pawl 5 at the teeth 5a, 5b interposed with the notches 7a of the piston 3.
• a downstream shift between the contact points of the teeth 5a, 5b in their notches 7a and the point P of the piston 3 in line with the axis 6 of rotation of the pawl 5 makes it possible to carry out this bracing.
• the respective radii Ra and Rb of the teeth 5a and 5b are greater than the distance separating the axis 6 at the point P. This bridging makes it possible to perform the anti-return function.
• the piston 3 can not then enter the body 2 of the tensioner 1.
• This arrangement makes it possible to advantageously leave a degree of freedom in translation of the piston 3 in the direction of retraction of the piston 3 into the body 2 by a distance greater than the inter-notch distance 7a between the tilting of the pawl in a notch 7a and the anti-return lock.
• This hysteresis zone is necessary for the proper operation of the chain or belt drive unit.
• FIGS 4 and 4a taken in combination with Figure 1, illustrate a first position in the locking process. In this position, the hydraulic tensioner 1 is fully debated following disassembly or unlocking. The hydraulic tensioner 1 then unlocked leaves the piston 3 under the effect of the first spring 4, the tooth 5b toggling notch up to the upstream end of the series 7 notches.
• the geometry of the pawl 5 does not allow the piston 3 to be ejected from the body 2 of the hydraulic tensioner 1 because the second tooth 5b of the pawl 5 holds the piston 3 against a wall 7b delimiting the upstream end of the series 7 of notches, this wall 7b being provided higher than the notches 7a so that the outlet of the piston 3 further rotates the pawl 5.
• the third tooth 5c then bears against the piston 3 to block the rotation of the pawl 5 and prevent the tooth 5b to leave the wall 7b.
• the radii of the locking tooth Rc (FIG. 8) and Rb (FIG.
• the initial position in the locking method according to the present invention may be that for which the hydraulic tensioner 1 does not contain fluid. hydraulic and the piston 3 is in a complete output position of the body 2 as described in Figures 4 and 4a.
• Figures 5 and 5a taken in combination with Figure 1, illustrate a second position in the locking method.
• the pawl 5 may have a bearing zone 5d.
• a pressure, for example the finger of a user, on the bearing zone 5d makes the forced pivoting of the pawl 5 in the downstream direction, therefore in opposition with the second spring 8, leading to the release of the second tooth 5b of a notch 7a of the series 7 of notches carried by the piston 3.
• the teeth 5a to 5c and the bearing zone 5d can be carried by the periphery of the pawl 5.
• the first and second teeth 5a and 5b can be relatively close to each other in order to penetrate into notches 7a respective neighbors but not necessarily adjacent in the series 7 notches 7a.
• the respective notches 7a of the first and second teeth 5a, 5b can interpose and leave between them a notch.
• the third tooth 5c is positioned relatively spaced relative to the first and second teeth 5a, 5b.
• the three teeth 5a to 5c point towards the piston 3 while the bearing zone 5d is in a portion of the periphery of the pawl 5 which is approximately diametrically opposed to an area of the periphery of the pawl 5 carrying the teeth 5a to 5c.
• the bearing zone 5d is preferably in the form of a step for the rest of the finger of the user against this step.
• the pressure of the user's finger on the bearing zone 5d ensures the maintenance of the pawl 5 in this release position of the second tooth 5b notches 7.
• FIGS 6 to 9, 6a to 9a and 9b taken in combination with Figure 1, illustrate a third position in the locking method. At the end of this position, the hydraulic tensioner 1 is locked and the piston 3 is retracted into the body 2 of the hydraulic tensioner.
• the piston 3 can not come out because when the third tooth 5c is engaged in a notch 7a, the fact that the first return means 4 push the piston out causes a jamming of the pawl 5 at this locking tooth.
• the radius Rc of the tooth 5c is greater than the distance separating the axis 6 at the point P.
• this locking step it is proceeded to the progressive release of the pressure on the piston 3 followed by releasing the finger pressure on the bearing zone of the pawl 5.
• This causes a pivoting of the pawl 5 in the direction upstream and the introduction of the third tooth 5c in a notch 7a of the series 7 locking the piston 3 in position relative to the body 2.
• FIGS. 9, 9a and 9b illustrate a first unlocking position which is that of the unlocking threshold in an unlocking method according to the present invention.
• Unlocking the hydraulic tensioner 1 from the locking position is performed with a simple pressing on the piston 3 in the upstream direction.
• This support can be manual or generated by the movements of the mobile guide guide of the chain during the first start of the engine following the installation of the hydraulic tensioner 1 in locked mode.
• Figures 10 and 10a illustrate the second unlocking position which is that of the working position of the hydraulic tensioner 1 and particularly its piston 3 after unlocking the assembly in the locking process.
• a manual support on the free end of the piston or a support generated by the movements of the chain during the first use of the hydraulic tensioner associated with the chain then causes a pivoting of the pawl 5 in the upstream direction, contrary to locking. It then releases the third tooth 5c of its notch 7a in which it was inserted, this advantageously under the action of the second spring 8, and a displacement of the piston 3 projecting from the body.
• Such a hydraulic tensioner may therefore be part of a closed chain drive assembly or closed belt, the free end of the piston being able to press on an intermediate system itself in contact with the chain or the belt for its tensioning.
• the intermediate system is, for example a chain guide.
• the intermediate system may be a roller.
• the closed chain or closed belt can be a chain or a timing belt of a heat engine, this engine being able to equip a vehicle.
• the hydraulic tensioner according to the present invention has the advantage of using the anti-return system with a pivoting ratchet equipped with teeth to also perform the locking of the piston, this with a slight modification of the ratchet by adding a third tooth or locking tooth.
• the anti-return and piston locking systems use the same components to perform both of these functions.
• Such a locking system is independent of the orientation with respect to gravity and therefore does not require a specific position.
• Such a system has a support area for a user's finger that allows it to be manually locked without tools.
• the invention is not limited to the embodiments described.
• the pawl may have only one anti-return tooth. In this case, however, the absence of second anti-return tooth does not allow to obtain a hysteresis zone in the upstream direction greater than one inter-screen.
• the tensioner may not be hydraulic, that is to say, it is not intended to receive a hydraulic fluid to assist the maintenance of the piston.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=55361682

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (5)

• 2015
  • 2015-11-25 FR FR1561338A patent/FR3044060B1/fr active Active
• 2016
  • 2016-10-19 CN CN201680066449.5A patent/CN108291616A/zh active Pending
  • 2016-10-19 EP EP16809904.2A patent/EP3380752A1/de not_active Withdrawn
  • 2016-10-19 WO PCT/FR2016/052705 patent/WO2017089663A1/fr not_active Ceased

Also Published As

Similar Documents

Legal Events