JP4906154B2 - Hydraulic tensioner - Google Patents

Description

  The present invention relates to the field of hydraulic tensioners with check devices. More particularly, the present invention relates to a hydraulic tensioner having a releasable rotation stopper and a method for releasing the same.

  The timing system of an internal combustion engine is controlled by a chain wound around two or more sprockets. One of the two sprockets is a drive sprocket that receives the driving force from the drive shaft directly or indirectly and transmits it to one or more driven sprockets.

  It is often necessary to compensate for chain slack to some extent for adjustment, material wear and / or removal of play. It is known in the art to use shoe tensioning devices in which the shoe is biased with an adjustable force against the chain span.

  Various means are known for biasing the tensioning shoe against the chain. The most frequently used means is a hydraulic tensioner. In a hydraulic tensioner, a fixed member (generally a cylinder) is attached to the engine block, and a movable member (generally a piston) is slidable with respect to the fixed member, acting on a shoe arranged to contact the chain. And apply tension to the chain.

  In such a tensioning device, the piston moves toward a shoe disposed opposite to the chain span by the cooperative action of a pressurized fluid (generally oil) and a spring supplied into the cylinder chamber via a check valve. Pushed out of the cylinder. Any slack in the chain due to heat, wear and / or passage of time is compensated by the piston protruding from the cylinder under the action of the biasing means.

  When the pressurized fluid supplied into the cylinder chamber cannot be used (for example, when the engine is stopped or immediately after the engine is started), the piston is pressed by the chain tension, and a part thereof is pushed into the cylinder. This causes slack in the chain.

  This will not accurately transfer motion from the drive sprocket to the driven sprocket, thereby compromising the efficiency and reliability of the timing system and putting the engine out of phase.

  European Patent 1,188,955, which is incorporated herein by reference, cooperates with a rack coupled to the piston to prevent the piston from returning into the cylinder when pressurized fluid is not available. It is disclosed to solve the above-mentioned problems by connecting a cylinder to a pole.

  In order to improve the reliability of the "rack pole" check device and prevent the piston from accidentally rotating with respect to the cylinder so that the rack does not come off the pole, for example, formed along the outer wall of the piston An anti-rotation means or anti-rotation device is provided, such as a closed and closed longitudinal groove. A pin provided integrally with the cylinder is slidably engaged with a longitudinal groove of the piston.

  The anti-rotation means or anti-rotation device further prevents accidental withdrawal of the piston from the cylinder. However, when the tensioner is removed from the engine, the anti-rotation means does not allow the piston to return into the cylinder without the usual long and expensive action. For example, facilitating transport and storage of the tensioner and / or reuse of the tensioner for other engines typically involves long and expensive activities.

The present invention has been made to solve the above-described conventional problems, and its purpose is to disengage the rack from the pole by the operator rotating the piston around the longitudinal axis, An object of the present invention is to provide a hydraulic tensioner capable of easily returning a piston into a cylinder.
European Patent No. 1,188,955

  Thus, the present invention seeks to provide a hydraulic tensioner that can easily return the piston into the cylinder.

The invention of claim 1 includes a cylinder having a cylinder hole and a pole hole, and a piston is slidably supported in the cylinder hole to limit a fluid chamber between the cylinder hole and a spring disposed in the cylinder hole. Is a hydraulic tensioner that urges the piston in a direction protruding from the cylinder hole. This hydraulic tensioner is composed of a pole provided in the pole hole and rack teeth formed along the length direction of the piston, and allows reverse movement of the piston and prevents reverse movement. And a first groove extending in the longitudinal direction and formed in the piston so as to receive a pin provided on the cylinder, and a second groove connected to the first groove and extending in a direction intersecting the first groove. And an anti-rotation device. When the piston is fully extended from the cylinder, the piston is disengaged from the non-return device by rotating the piston and moving the pin from the first groove to the second groove to release the anti-rotation device. It will be released.

  In the invention of claim 2, the second groove extends in a direction orthogonal to the first groove.

  In the invention of claim 3, the second groove is connected to one end of the first groove in the vicinity of the end of the piston.

In the invention of claim 4, as the bottom surface of the second groove moves away from the first groove, it approaches the outer peripheral surface of the piston and is connected to the outer peripheral surface .

  In the invention of claim 5, the pin is held at a predetermined position by the flexible thin film portion provided on the outer surface of the cylinder.

In the invention of claim 6, the flexible membrane portion has two opposite flaps, these flaps, are formed in an L shape extending in the longitudinal direction and the direction crossing the cylinder Yes.

The invention of claim 7 includes a cylinder having a cylinder hole and a pole hole, and a piston is slidably supported in the cylinder hole to limit a fluid chamber between the cylinder hole and a spring disposed in the cylinder hole. Is a hydraulic tensioner that urges the piston in a direction protruding from the cylinder hole. This hydraulic tensioner is composed of a pole provided in the pole hole and a rack tooth formed along the length direction of the piston, and allows movement in the protruding direction of the piston and prevents movement in the backward direction. Non-return device, and a first groove extending in a longitudinal direction formed in a piston to receive a pin provided in a cylinder, and a rotation prevention device comprising a throat portion connected to the first groove and intersecting the first groove And. When the piston is fully extended from the cylinder, the piston is disengaged from the check device by rotating the piston and moving the pin from the first groove to release the anti-rotation device. It has come to be.

  In the invention of claim 8, the throat extends over the entire circumference of the piston.

  In the invention of claim 9, the throat portion is orthogonal to the first groove.

The invention of claim 10 includes a cylinder having a cylinder hole and a pole hole, and a piston is slidably supported in the cylinder hole to limit a fluid chamber between the cylinder hole and a spring disposed in the cylinder hole. In the hydraulic tensioner that urges the piston in the direction protruding from the cylinder hole, it is composed of a pole provided in the pole hole and rack teeth formed along the length direction of the piston. A first longitudinally extending groove formed in the piston for receiving a pin provided on the cylinder and connected to the first groove, and having a check device for allowing the movement of the cylinder and preventing the movement in the backward direction A method for deactivating a rotation stop device having a second groove or throat. This method includes the following steps. That is,
a) Pulling the piston out of the cylinder until the pin reaches one end of the first groove.
b) Disengaging the piston from the non-return device by rotating the piston relative to the cylinder to move the pin to the second groove or throat.

  In the invention of claim 11, the second groove is orthogonal to the first groove.

In the invention of claim 12, throat portion is perpendicular to the first groove.

  In the present invention, there is provided a hydraulic tensioner including a rotation stopping device capable of releasing the engagement of the piston of the hydraulic tensioner from the check device. A function release method for the rotation stop device is also disclosed.

  An anti-rotation device or anti-rotation means that can be disengaged and a hydraulic tensioner with a non-return device are provided. The anti-rotation device has a pin integral with the tensioner cylinder that slides in a longitudinal groove formed in the outer wall of the piston, and means for deactivating the anti-rotation device.

  The disengagement means or disengagement device has a second groove connected to the end of the first groove in the longitudinal direction in the vicinity of the bottom of the cylinder and orthogonal to the first groove. Alternatively, the disengaging means or the disengaging device extends over the entire circumference of the piston and is connected to the first groove in the longitudinal direction and has a throat portion orthogonal to the first groove. The second groove is preferably formed as a ramp that connects the bottom of the longitudinal groove with the outer surface of the piston.

According to the present invention, a piston check device composed of a pole and rack teeth engaged therewith, a longitudinal first groove formed in the piston to receive a cylinder pin and connected thereto. And the anti- rotation device comprising the second groove extending in a direction intersecting with the second groove, so that when the piston is fully extended from the cylinder, the piston is rotated to move the pin from the first groove to the second groove. The piston can be disengaged from the non-return device by releasing the function of the anti-rotation device by moving it to the groove or throat . In this way, the piston can be easily returned into the cylinder.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, in each figure, the corresponding member is shown with the same referential mark.
FIG. 1 is an overall perspective view of a hydraulic tensioner piston 3 according to a first embodiment of the present invention, and FIG. 2 is a sectional view of the hydraulic tensioner including the piston of FIG.

  The groove on which the pin 12 slides is formed in an L shape, and is connected to the first groove 6 extending in the longitudinal direction and the end of the first groove 6 in the vicinity of the bottom of the cylinder 2, and the first groove 6 It is comprised from the groove | channel and the 2nd groove | channel 11 extended in the direction which makes 90 degree | times. The second groove is preferably formed as an inclined surface that connects the bottom of the first groove 6 to the outer surface of the piston 3.

  The hydraulic tensioner 1 has a cylinder or housing 2 and a piston 3 slidably accommodated in a hole of the cylinder 2. The piston 3 forms a cylindrical fluid chamber 4 with the cylinder 2. The piston 3 has a rack 5 that interacts with a pole 7 accommodated in a pole hole of the cylinder 2.

  The rack 5 and the pole 7 constitute a check means, which allows movement of the piston 3 in the protruding direction and prevents movement in the retracted direction. The piston 3 is hollow inside and houses a spring 8. The spring force generated by the spring 8 acts between the tip 9 of the piston 3 and the bottom of the chamber 4. The chamber 4 is fluidly connected to a circuit for supplying pressurized fluid, typically oil, via an aperture 10 and a check valve (not shown).

  The resultant pressure of the pressurized fluid in the chamber 4 and the spring force of the spring 8 urges the piston 3 outward from the cylinder 2. As a result, the piston 3 comes into contact with a shoe (not shown) via the tip end portion 9, and a tension force acts on the chain. Also shown in FIG. 2 is a pin 12 that can engage the first groove 6 and the second groove 7 in the longitudinal direction.

  FIG. 3 shows a state in which the piston 3 is fully extended from the cylinder 2. Such a state can be easily realized when the tensioner is not attached to the engine. At this time, the piston 3 protrudes from the cylinder 2 by the elastic repulsive force and / or its own weight of the spring 8 (not shown).

  In FIG. 3, the pole 7 is engaged with the final tooth portion of the rack 5, and at this time, the pin 12 is engaged with one end of the first groove 6 in the longitudinal direction, and the piston 3 is a cylinder. 2 is prevented from slipping down.

  FIG. 4 shows a state in which the first groove 6 and the pin 12 constituting the rotation stop means are disengaged. In this case, the pin 12 is caused to enter the second groove 11 from the end of the first groove 6 by rotating the piston 3 around the longitudinal axis from the state shown in FIG. Thereby, the pole 7 is detached from the rack 5 and is disengaged.

  In FIG. 4, the pin 12 is held at a predetermined position by a flexible thin film portion 13 (see FIG. 6) attached to the outer surface of the cylinder 2. The pin 12 has come out of the first groove 6 in the longitudinal direction and is in contact with the outer surface of the piston 3.

  FIG. 5 shows a state in which the piston 3 is completely retracted into the cylinder 2 and the piston 3 is locked at the retracted position by rotating the piston 3 and engaging the pole 7 with the rack 5. The pin 12 is engaged with the other end of the first groove 6 in the longitudinal direction, and the second groove 11 appears. This locked state is convenient for transportation and storage of the hydraulic tensioner 1.

FIG. 6 is a side view of the tensioner of FIG. 5, showing the cylinder 2, the piston 3 fully retracted in the cylinder 2, and the flexible thin film portion 13 that holds the pin 12 in place. .
In the preferred embodiment shown in FIG. 6, the flexible thin film portion 13 has two flaps 15. These flaps 15 are formed in an L shape, and at least a part thereof overlaps. In FIG. 6, the flaps 15 are slightly separated and the lower pins 12 appear.

The method of canceling the function of the rotation stopping means 6 and 12 includes the following steps.
First, the piston 3 is pulled out from the cylinder 2 and the pin 12 is placed in the first groove 6 at the position of the second groove 11.

  Next, the piston 3 is rotated, for example, clockwise with respect to the cylinder 2, and the pin 12 is moved into the second groove 11. As a result, the pole 7 is disengaged from the rack 5. In this state, the piston 3 can be returned into the cylinder 2. Thereafter, the piston 3 is fixed at that position by rotating the piston 3 counterclockwise, for example.

  FIG. 7 shows a hydraulic tensioner piston 3 'according to a second embodiment of the present invention. This piston 3 ′ is different from the piston 3 shown in FIG. 1 in that the groove is not formed in an L shape and the throat portion (small diameter portion) 14 orthogonal to the groove 6 ′ is terminated. Yes. The throat portion 14 extends over the entire circumference of the piston 3 '.

  The method of deactivating the anti-rotation means 6, 12 is the same as described above with reference to FIGS. 1 to 4 and is shown in FIG. In FIG. 8, the piston 3 ′ extends completely from the cylinder 2, the pin 12 is disposed in the throat portion 14, and the rack 5 is engaged with the pole 7. To disengage the rack 5 from the pole 7, the piston 3 'is rotated (see FIG. 9).

  FIG. 10 shows the hydraulic tensioner 1 with the piston 3 ′ fully retracted into the cylinder 2. In the figure, holes 16 and 17 are formed in the sleeve of the cylinder 2. The hole 16 is closed by the pin 12, and the hole 17 indicates the region of the groove 6 'below.

  It is to be understood that the embodiments of the invention described herein are merely exemplary of employing the principles of the present invention. Reference herein to details of the embodiments describing features considered essential to the invention is not intended to limit the scope of the claims.

1 is an overall perspective view of a piston of a hydraulic tensioner according to the present invention. It is sectional drawing of the hydraulic tensioner provided with the piston of FIG. FIG. 3 is a cross-sectional view of the hydraulic tensioner of FIG. 2 showing a state where the piston is fully extended from the cylinder. FIG. 3 is a cross-sectional view of the hydraulic tensioner of FIG. 2, showing a state where the piston is completely extended from the cylinder and rotated to remove the rack from the pole. In the hydraulic tensioner of FIG. 2, a state in which the piston is completely retracted into the cylinder is shown. It is a side view of the hydraulic tensioner of FIG. It is a whole perspective view which shows the piston of the hydraulic tensioner by the 2nd Example of this invention. FIG. 8 is a cross-sectional view of a hydraulic tensioner including the piston of FIG. 7, showing a state where the piston is completely extended from the cylinder. FIG. 9 is a cross-sectional view of the hydraulic tensioner of FIG. 8, showing a state in which the piston is completely extended from the cylinder and rotated to remove the rack from the pole. It is a side view of the hydraulic tensioner of FIG. 8, Comprising: The piston has shown the state fully retracted in the cylinder.

1: Hydraulic tensioner 2: Cylinder 3: Piston 4: Fluid chamber 5: Rack 6: First groove 7: Pole 8: Spring 11: Second groove 12: Pin 13: Flexible thin film part 14: Throat part 15: Flap

Claims (12)

A cylinder (2) having a cylinder hole and a pole hole is provided, and a piston (3) is slidably supported in the cylinder hole to limit the fluid chamber (4) between the cylinder hole and disposed in the cylinder hole. In the hydraulic tensioner (1) in which the spring (8) biases the piston (3) in a direction protruding from the cylinder hole,
It is composed of a pole (7) provided in the pole hole and a rack tooth (5) formed along the length direction of the piston (3), allowing the piston (3) to move in the protruding direction and retreating direction. A check device for preventing movement of the
A longitudinally extending first groove (6) formed in the piston (3) to receive a pin (12) provided in the cylinder (2) and connected thereto and a first groove (6); An anti- rotation device comprising a second groove (11) extending in the intersecting direction,
When the piston (3) is fully extended from the cylinder (2), the piston (3) is rotated to move the pin (12) from the first groove (6) to the second groove (11). in by acting release the detent device, the piston (3) is adapted to be disengaged from the non-return device,
A hydraulic tensioner characterized by that. In claim 1,
The second groove (11) extends in a direction perpendicular to the first groove (6),
A hydraulic tensioner characterized by that. In claim 1,
The second groove (11) is connected to one end of the first groove (6) in the vicinity of the end of the piston (3).
A hydraulic tensioner characterized by that. In claim 1,
As the bottom surface of the second groove (11) moves away from the first groove (6), it approaches the outer peripheral surface of the piston (3) and is connected to the outer peripheral surface .
A hydraulic tensioner characterized by that. In claim 1,
The pin (12) is held at a predetermined position by the flexible thin film portion (13) provided on the outer surface of the cylinder (2).
A hydraulic tensioner characterized by that. In claim 5,
The flexible thin film portion (13) has two opposing flaps (15), and these flaps (15) are L-shaped extending in the longitudinal direction of the cylinder (2) and in a direction intersecting with the longitudinal direction. They are formed in,
A hydraulic tensioner characterized by that. A cylinder (2) having a cylinder hole and a pole hole is provided, and a piston (3) is slidably supported in the cylinder hole to limit the fluid chamber (4) between the cylinder hole and disposed in the cylinder hole. In the hydraulic tensioner (1) in which the spring (8) biases the piston (3) in a direction protruding from the cylinder hole,
It is composed of a pole (7) provided in the pole hole and a rack tooth (5) formed along the length direction of the piston (3), allowing the piston (3) to move in the protruding direction and retreating direction. A check device for preventing movement of the
A longitudinally extending first groove (6) formed in the piston (3) to receive a pin (12) provided in the cylinder (2) and connected thereto and a first groove (6); Equipped with an anti-rotation device consisting of intersecting throats (14),
When the piston (3) is fully extended from the cylinder (2), the piston (3) is rotated to move the pin (12) from the first groove (6) to the throat (14). By releasing the function of the rotation stop device, the piston (3) is disengaged from the check device.
A hydraulic tensioner characterized by that. In claim 7,
The throat (14) extends over the entire circumference of the piston (3),
A hydraulic tensioner characterized by that. In claim 7,
The throat (14) is orthogonal to the first groove (6),
A hydraulic tensioner characterized by that. A cylinder (2) having a cylinder hole and a pole hole is provided, and a piston (3) is slidably supported in the cylinder hole to limit the fluid chamber (4) between the cylinder hole and disposed in the cylinder hole. In the hydraulic tensioner (1) in which the spring (8) urges the piston (3) in a direction protruding from the cylinder hole, the length of the pole (7) provided in the pole hole and the piston (3) is lengthwise. Provided with a check device for allowing the piston (3) to move in the projecting direction and preventing the piston (3) from moving in the reverse direction, and is provided on the cylinder (2). A longitudinally extending first groove (6) and a second groove (11) or throat (14) connected thereto formed in the piston (3) to receive the pin (12) formed Have A method for function release the rotation stop device,
a) pulling the piston (3) out of the cylinder (2) until the pin (12) reaches one end of the first groove (6);
b) By rotating the piston (3) relative to the cylinder (2), the pin (12) is moved to the second groove (11) or the throat (14) and the piston (3) is non-returned. Disengaging from the device;
With a method. In claim 10,
The second groove (11) is orthogonal to the first groove (6),
A method characterized by that. In claim 10,
Throat (14) is perpendicular to the first groove (6),
A method characterized by that.

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