JP2005140237A - Tension adjusting device for wrapping connecting member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt tension adjusting device capable of contributing to low fuel consumption by weakening belt tension during the low rotation of an engine so as not to increase the rotational resistance of a crankshaft and a camshaft. <P>SOLUTION: A tension pulley 6 is brought into contact with a timing belt 5 for driving the camshaft, and an auto tensioner 10 and a thrust applying device 30 are connected to a swingable pulley arm 7 for pressing the tension pulley 6 to the timing belt 5. Two thrusts of the auto tensioner 10 and thrust applying device 30 are applied to the pulley arm 7 during the operating rotation of an engine, or the thrust of the thrust applying device 30 is optionally applied when necessary. Only the thrust of the auto tensioner 10 is applied during low rotation to weaken the tension of the timing belt 5. The rotational resistance of the crankshaft and camshaft is thereby reduced to contribute to low fuel consumption. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention mainly relates to a tension adjusting device that maintains a constant tension of a winding transmission member such as a chain driving a camshaft or a timing belt.

  In general, in a belt transmission device that transmits the rotation of a crankshaft to an internal combustion engine to a camshaft, a timing pulley is attached between the end of the crankshaft and the end of the camshaft, and a toothed pulley is installed between the ends of the toothed pulley. A tension pulley is brought into contact with the slack side, and an adjustment force of a hydraulic auto tensioner is applied to a pulley arm that supports the tension pulley so as to keep the tension of the timing belt constant.

  As the hydraulic auto tensioner, those described in Patent Document 1 and Non-Patent Document 1 are known. This hydraulic auto tensioner inserts a rod into the cylinder chamber formed in the body, gives the rod a spring force of a tension adjustment spring to give outward protrusion, and the axial direction loaded on the rod The pushing force is buffered by a hydraulic damper.

  The thrust (pressing force) by which the auto tensioner presses the pulley arm is determined by the tension adjusting spring, and the thrust is substantially constant. On the other hand, the belt tension is not constant but constantly fluctuates. For this reason, a fluctuating load acts on the rod of the auto tensioner. This fluctuating load differs depending on the number of cylinders of the engine, the maximum rotational speed, the engine load, and the like.

  FIG. 10 shows an example of a fluctuating load acting on a rod of an auto tensioner in a V-type 6-cylinder engine (V6 engine). FIG. 11 (I) shows the change in load acting on the rod of the auto tensioner and the displacement of the tension pulley when the rotational speed of the V6 engine is increased, and FIG. 11 (II) shows the series It shows the change in load acting on the rod of the auto tensioner and the displacement of the rod when the rotational speed of the 4-cylinder engine (L4 engine) is increased.

  The maximum value of the fluctuating load shown in FIG. 10 is determined by the characteristics of the hydraulic damper, while the minimum value is determined by the tension adjustment spring. The fluctuation of the maximum value is determined by the characteristics of the engine, and as shown in FIGS. 11 (I) and 11 (II), there is a difference in characteristics depending on the engine type.

Generally, in order to determine various characteristics of an auto tensioner, a hydraulic damper in which the minimum load is not less than zero and an abnormal amplitude is not selected is performed. Conventionally, when setting the spring force of the tension adjustment spring, the spring force is set so that the minimum load does not fall below zero based on the resonance point and peak value of the maximum load.
No. 3-13647 NTN TECHNICICAL REVIEW No. 61 (1992), P57 to P63

  By the way, in a conventional auto tensioner in which the spring force of the tension adjustment spring that presses the rod is set so that the minimum load is not less than zero based on the resonance point or peak value of the maximum load, idling is a measure for reducing fuel consumption. If the engine speed at this time is set to a low speed of 1000 rpm or less, the belt tension due to the spring force of the tension adjustment spring acts on the camshaft and crankshaft to cause rotational resistance, which contributes to low fuel consumption. There was an inconvenience that it was not possible.

  Here, if the spring force of the tension adjustment spring is made to correspond to the low rotation of the engine, there is a problem that the tension of the belt cannot be kept constant due to insufficient spring force at the resonance point or peak at the maximum load. To do.

  An object of the present invention is to reduce the rotational resistance of the crankshaft and the camshaft by reducing the tension of the winding transmission member for driving the camshaft when the engine is running at low speed, and in a practical rotational state in which the vehicle is driven. Another object of the present invention is to provide a tension adjusting device for a winding transmission member that can hold the winding transmission member at an appropriate tension.

  In order to solve the above-mentioned problems, in the first invention, a rotatable tension pulley is brought into contact with an endless winding transmission member that transmits rotation of a crankshaft to a camshaft, and the tension pulley is wound around the transmission member. Apply the pressing force of the auto tensioner to the swingable pulley arm that is moved with respect to the tension pulley, press the tension pulley against the transmission member, the auto tensioner is a rod whose tip is in contact with the pulley arm, and the rod to the pulley arm In a tension adjusting device for a wound transmission member having a tension adjusting spring that biases the rod and a hydraulic damper that cushions an axial pushing force applied to the rod. The minimum load at the time of switching to a practical rotation for running the vehicle, or at the resonance point at the maximum load or peak load In order to be able to arbitrarily change the thrust so as not to fall below zero, a thrust adding device is provided that applies a thrust to the pulley arm and biases the pulley arm in a direction in which the tension pulley presses the winding member. .

  Here, the thrust adding device may be provided in parallel to the auto tensioner, or may be provided in series to the auto tensioner.

  As the thrust addition device, a cylinder chamber formed in the body is slidably incorporated with a piston that divides the interior into a lower chamber and an upper chamber, and an inlet is provided that communicates with the lower chamber and is supplied with hydraulic pressure. In addition, it is possible to employ a configuration in which an outlet is provided in communication with the upper chamber and a rod for pressing the pulley arm is provided on the piston, or a solenoid having a push rod.

  In the second aspect of the invention, the endless winding transmission member that transmits the rotation of the crankshaft to the camshaft is brought into contact with the rotatable tension pulley and the tension pulley is moved with respect to the winding transmission member. Applying the tension force of the auto tensioner to the possible pulley arm, wrap the tension pulley and press it against the transmission member. In a tension adjusting device for a wound transmission member comprising a spring and a hydraulic damper that cushions an axial pushing force applied to the rod, the auto tensioner is supported swingably so that the engine is idling. Resonance point at maximum load when the vehicle is switched from low rotation to practical operation to drive the vehicle A configuration that includes an actuator that swings the auto tensioner in a direction in which the contact position of the rod with respect to the pulley arm moves away from the swing center of the pulley arm so that the thrust can be arbitrarily changed so that the minimum load at the peak load does not fall below zero. Can be adopted.

  As in the first aspect of the invention, by providing a thrust adding device that applies thrust to the pulley arm when the engine is switched to a practical rotation at which the engine is loaded, the auto tensioner is operated at a low speed when the engine is idling. Since only the thrust is applied to the pulley arm, the spring force of the tension adjustment spring that imparts outward protrusion to the rod can be set to a small value that does not increase the rotational resistance of the crankshaft or camshaft. , Can contribute to low fuel consumption measures for idling.

  In addition, when the engine is switched from a low rotation during idling operation to a practical rotation for running the vehicle, the thrust of the thrust adding device is added to the pulley arm, so that at the maximum load of the variable load due to the tension fluctuation of the winding transmission member There is no problem that the tension force of the tension adjusting spring is insufficient at the resonance point or the peak value, and the tension of the wound transmission member can be always kept constant.

  In the second aspect of the invention, the position at which the rod of the auto tensioner pushes the pulley arm is changed by swinging the auto tensioner by operating the actuator, and the rotational moment applied to the pulley arm is changed by the change in the position. Can be made.

  For this reason, when the engine is set to a low rotation speed of 1000 rpm or less, for example, the pressing force of the tension pulley that presses the transmission member is moved by displacing the pressing position of the rod that presses the pulley arm toward the oscillation center of the pulley arm. Since the tension of the winding transmission member can be reduced and the rotational resistance of the crankshaft and camshaft can be reduced, it is possible to contribute to measures for reducing fuel consumption.

  In addition, when the engine is switched from a low rotation during idling operation to a practical rotation for running the vehicle, the tension pulley is wound by displacing the pressing position of the rod that presses the pulley arm in the direction away from the swing center of the pulley arm. Since the pressing force for pressing the hanging transmission member can be increased, the winding transmission member can be held at an appropriate tension, and can always be held at a constant tension by the auto tensioner.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 show a first embodiment of a tension adjusting device according to the present invention. As shown in the figure, toothed pulleys 3 and 4 are attached to the end of the crankshaft 1 and the end of the camshaft 2, and a timing belt 5 as a wound transmission member is hung between the toothed pulleys 3 and 4. Passed.

  In the first embodiment, the rotation of the crankshaft 1 is transmitted to the camshaft 2 by the belt transmission, but the transmission is not limited to this. For example, a chain transmission device may be employed. When the chain transmission device is employed, a sprocket is attached to each of the ends of the crankshaft 1 and the camshaft 2, and a chain as a winding transmission member is spanned between the sprockets.

  A tension pulley 6 is provided on the slack side of the timing belt 5. The tension pulley 6 is rotatably supported by a pulley arm 7. The pulley arm 7 is supported to be swingable about a shaft 8, and an auto tensioner 10 and a thrust adding device 30 are provided in association with the pulley arm 7.

  The auto tensioner 10 and the thrust adding device 30 share the body 11 made of an aluminum alloy attached to the engine block. The auto tensioner 10 is fitted with a steel sleeve 13 at the bottom of the first cylinder chamber 12 formed in the body 11, and the upper opening of the first cylinder chamber 12 is sealed by attaching an oil seal 14. Leakage of the hydraulic oil filled in the first cylinder chamber 12 and an air layer on the hydraulic oil is prevented, and the spring 15 of the tension adjusting spring 16 is applied to the rod 15 slidably penetrating the oil seal 14 to remove the hydraulic oil. Protrusion in the direction is imparted, and the axial pushing force applied to the rod 15 by the hydraulic damper 17 incorporated in the sleeve 13 is buffered.

  Here, the tension adjusting spring 16 is incorporated so that the lower portion is inserted into a cylindrical space 18 formed between the outer periphery of the sleeve 13 and the inner periphery of the first cylinder chamber 12. The tension adjusting spring 16 imparts outward protrusion to the rod 15 via a wear ring 19 fitted to the outside of the rod 15, and the wear ring 19 is an inner peripheral surface of the first cylinder chamber 12. It is possible to slide along.

  The hydraulic damper 17 connects a plunger 20 slidable along the inner peripheral surface of the sleeve 13 to the lower end portion of the rod 15, and the hydraulic oil in the pressure chamber 21 formed below the plunger 20 is attached to the rod 15. The applied axial pushing force is buffered.

  The plunger 20 is formed with a passage 23 that allows the lower pressure chamber 21 and the upper reservoir chamber 22 to communicate with each other, and a check valve 24 is provided at an end opening of the passage 23 on the pressure chamber 21 side. The check valve 24 closes the passage 23 when the pressure in the pressure chamber 21 becomes higher than the pressure in the reservoir chamber 22. Reference numeral 25 denotes a plunger spring that presses the plunger 20 against the rod 15.

  The auto tensioner 10 having the above configuration is assembled to press the pulley arm 7 from the rod 15. When the timing belt 5 is loosened in the assembled state, the rod 15 is moved outward by the spring force of the tension adjusting spring 16, and the pulley arm 7 is pushed by the rod 15, and the tension pulley 6 moves the timing belt 5. It swings in the pressing direction, and the slack of the timing belt 5 is absorbed by the swing.

  Further, when the tension of the timing belt 5 increases and the rod 15 is pushed through the tension pulley 6 and the pulley arm 7, the pushing force is buffered by the hydraulic damper 17.

  When the pushing force is larger than the spring force of the tension adjusting spring 16, the hydraulic oil in the pressure chamber 21 leaks into the reservoir chamber 22 from between the sliding surfaces of the plunger 20 and the sleeve 13, and the tension adjusting spring 16 and the pushing force are pushed. The rod 15 and the plunger 20 are pushed to a position where they are balanced, and the tension of the timing belt 5 is made constant.

  The thrust adding device 30 forms a second cylinder chamber 31 in the body 11 in parallel with the first cylinder chamber 12, and a piston 32 is slidably incorporated in the second cylinder chamber 31 so that the interior of the second cylinder chamber 31 is a lower chamber. 33 and an upper chamber 34, an inlet 35 is provided in communication with the lower chamber 33, an outlet 36 is provided in communication with the upper chamber 34, and hydraulic pressure is supplied from the inlet 35 into the lower chamber 33. The thrust is applied to the piston 32 and the rod 32a provided on the piston 32. This thrust is applied to the pulley arm 7 through the rod 32a, and the pulley arm 7 swings and the tension pulley 6 is pressed against the timing belt 5 by the addition of the thrust.

  In FIG. 2, reference numeral 37 denotes a seal member that seals the upper opening of the second cylinder chamber 31.

  The thrust adding device 30 having the above-described configuration is configured so that hydraulic pressure is supplied to the inlet 35 when the engine is switched from low rotation during idling operation to practical rotation during load operation in which the vehicle travels.

  Here, the hydraulic pressure supplied to the inlet 35 may be the engine hydraulic pressure as it is, or may be a pressure-controlled hydraulic pressure, or may be arbitrarily controlled.

  As described above, since the thrust addition device 30 applies thrust to the pulley arm 7 when the engine is put into practical rotation, only the thrust from the auto tensioner 10 is applied to the pulley arm 7 during low rotation when the engine is idling. Will be. For this reason, the spring force of the tension adjusting spring 16 that imparts outward protrusion to the rod 15 of the auto tensioner 10 can be set to a small value that does not increase the rotational resistance of the crankshaft 1 or the camshaft. This can contribute to lower fuel consumption at low revolutions.

  In addition, when the engine is switched from a low speed during idling to a practical speed for running the vehicle, two thrusts are added to the pulley arm 7, the thrust from the auto tensioner 10 and the thrust from the thrust adding device 30. Thus, there is no problem that the spring force of the tension adjusting spring 16 is insufficient at the resonance point or peak value at the maximum load of the fluctuating load due to the tension fluctuation of 5, and the tension of the timing belt 5 can be kept constant at all times.

  FIG. 4 shows a second embodiment of the tension adjusting device according to the present invention. This second embodiment is different from the tension adjusting device shown in the first embodiment of FIG. 1 in that the tension adjusting spring 16 of the auto tensioner 10 is incorporated in the pressure chamber 21 below the plunger 20. Since other configurations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  In the tension adjusting device shown in the second embodiment, the tension adjusting spring 16 of the tension adjusting device shown in the first embodiment can be omitted, so the number of parts is reduced and the cost can be reduced. .

  FIG. 5 shows a third embodiment of the tension adjusting device according to the present invention. This embodiment is different from the tension adjusting device of the first embodiment shown in FIG. 2 in that a thrust adding device 30 is provided in series with the auto tensioner 10.

  That is, the body 11 of the auto tensioner 10 is extended upward to form a second cylinder chamber 31 on the oil seal 14, a seal member 37 is attached to the upper opening of the second cylinder chamber 31, and the rod of the auto tensioner 10 is 15 is slidably passed through the seal member 37 and is brought into contact with the pulley arm 7. The second cylinder chamber 31 is partitioned into a lower chamber 33 and an upper chamber 34 by a piston 32 provided on the rod 15. An inlet 35 is provided in communication and an outlet 36 is provided in communication with the upper chamber 34, so that thrust is applied to the rod 15 by supplying hydraulic pressure to the lower chamber 33.

  Also in the tension adjusting device according to the third embodiment, the thrust applied to the rod 15 by the tension adjusting spring 16 of the auto tensioner 10 is applied to the pulley arm 7 at the time of low rotation at the time of idling of the engine. At the time of switching to the practical rotation for running the vehicle, hydraulic pressure is supplied from the inlet 35 to the lower chamber 33, and thrust applied to the piston 32 and the rod 15 is applied to the pulley arm 7.

  Also in the tension adjusting device according to the third embodiment, since the spring force of the tension adjusting spring 16 of the auto tensioner 10 can be set to a small value, the rotation of the crankshaft 1 and the camshaft 2 can be performed at a low rotation during idling. Resistance can be reduced, which can contribute to lower fuel consumption.

  FIG. 6 shows a fourth embodiment of the tension adjusting device according to the present invention. In this embodiment, as in the third embodiment shown in FIG. 5, the auto tensioner 10 and the thrust adding device 30 are provided in series, and the auto tensioner 10 shown in the second embodiment of FIG. It is different from the third embodiment in that it is used.

  For this reason, the same components as those in the second embodiment and the third embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIGS. 7 (I) and (II) show a fifth embodiment of the tension adjusting device according to the present invention. Similar to the tension adjusting device in the first embodiment, the tension adjusting device in the fifth embodiment also includes an auto tensioner 10 and a thrust adding device 30.

  The auto tensioner 10 rotatably supports a tension pulley 40 brought into contact with the timing belt 5 with a pulley support 41, passes a support shaft 42 at an eccentric position with respect to the center of the pulley support 41, and moves the support shaft 42. The pulley support 41 is supported by the engine block A so as to be swingable around the support shaft 42.

  Further, a spring housing recess 43 is formed in the pulley support 41, and the tension pulley 40 is timed by a tension adjustment spring 45 incorporated between the end surface of the spring housing recess 43 and the pin 44 fixed to the engine block A. The pulley support 41 is urged in the direction in which the belt 5 is pressed.

  Further, a hydraulic damper 46 is attached to the support shaft 42, a push rod 47 of the hydraulic damper 46 is brought into contact with a pin 48 provided on the pulley support body 41, and the pulley belt 41 is connected to the pulley support body 41 via the tension pulley 40 from the timing belt 5. The applied pressing force is buffered by the hydraulic damper 46.

  The thrust adding device 30 slidably incorporates a piston 54 that divides the inside into a lower chamber 52 and an upper chamber 53 in a cylinder chamber 51 formed in the body 50, and a rod 54 a provided on the piston 54. A sliding member 55 is slidably passed through a seal member 55 attached to the upper opening of the cylinder chamber 51, communicates with the lower chamber 52 to form an inlet 56, and communicates with the upper chamber 53 to provide an outlet 57. Hydraulic pressure is supplied from the inlet 56 to the lower chamber 52, and thrust applied to the piston 54 and the rod 54a is applied to the tip of the pulley arm 58 attached to the pulley support 41 of the auto tensioner 10 so that the tension pulley 40 The pulley support 41 is biased in the direction in which the timing belt 5 is pressed.

  Also in the tension adjusting device according to the fifth embodiment, when the engine is switched from the low rotation at idling to the practical rotation for running the vehicle, the hydraulic pressure is supplied to the inlet 56 of the thrust addition device 30, and the piston 54 and the rod 54a. The pulley arm 58 is pressed by the thrust applied to the timing belt 5 and the thrust of the auto tensioner 10 and the thrust of the thrust adding device 30 are applied to the timing belt 5 to adjust the tension of the timing belt 5.

  Also in the tension adjusting device according to the fifth embodiment, the spring force of the tension adjusting spring 45 can be set to a small value, and the rotational resistance of the crankshaft 1 and the camshaft 2 can be reduced during low rotation due to engine idling. Reduction can be achieved and it can contribute to the reduction in fuel consumption.

  FIG. 8 shows a sixth embodiment of the tension adjusting device according to the present invention. The sixth embodiment is different from the tension adjusting device shown in the first embodiment of FIG. 1 in that a solenoid is used as the thrust adding device 30 and the push rod 30a of the solenoid is connected to the pulley arm 7. .

  For this reason, the same code | symbol is attached | subjected to the same components as the tension adjustment apparatus shown in 1st Embodiment, and description is abbreviate | omitted.

  In the sixth embodiment, when the engine is switched from low rotation at idling to practical rotation for running the vehicle, the solenoid (thrust adding device 30) is energized to add thrust to the push rod 30a. Two thrusts of the thrust adding device 30 and the auto tensioner 10 are applied to the timing belt 5 to adjust the tension of the timing belt 5.

  FIG. 9 shows a seventh embodiment of the tension adjusting device according to the present invention. In this embodiment, the lower end portion of the auto tensioner 10 is swingably supported around the shaft 60, and the rod 62 of the swing driving actuator 61 is connected to the upper portion of the auto tensioner 10 to drive the actuator 61. Thus, the auto tensioner 10 is swung.

  Here, since the auto tensioner 10 is the same as the auto tensioner 10 shown in FIG. 2, the same components are denoted by the same reference numerals and description thereof is omitted.

  The tip of the rod 15 of the auto tensioner 10 is in contact with a guide piece 7a provided on the pulley arm 7, and is slidable along the guide piece 7a.

  In the tension adjusting device shown in the seventh embodiment, the rod 62 of the actuator 61 is moved forward at the time of low rotation due to engine idling to swing the auto tensioner 10 toward the shaft 8 that is the swing center of the pulley arm 7.

  Further, when the engine is switched from a low rotation to a practical rotation in which the vehicle travels, the rod 62 of the actuator 61 is retracted to swing the auto tensioner 10 away from the shaft 8.

  When the auto tensioner 10 is swung by the operation of the actuator 61 as described above, the contact position of the tip of the rod 15 with respect to the guide piece 7a and the distance to the shaft 8 change, and the change in the distance causes the rotational moment of the pulley arm 7 to change. Change.

  When the auto tensioner 10 is swung toward the shaft 8 when the engine is running at a low speed, the rotational moment is reduced, so that the pressing force with which the tension pulley 6 presses the timing belt 5 is reduced, and the tension of the timing belt 5 is weakened. Can do.

  For this reason, the rotational resistance of the crankshaft 1 and the camshaft 2 can be reduced, which can contribute to lower fuel consumption.

  Further, when the auto tensioner 10 is swung away from the shaft 8 during the practical rotation of the engine, the rotational moment of the pulley arm 7 increases and the tension pulley 6 is strongly pressed against the timing belt 5. Tension increases.

  For this reason, the spring force of the tension adjustment spring 16 is set to a spring force at which the minimum load does not fall below zero with reference to the resonance point and peak value of the maximum load of the variable load acting on the rod 15. Insufficiency of the spring force at the resonance point or load peak at the time of load can be prevented, and the tension of the timing belt 5 can be kept constant at all times.

The front view which shows 1st Embodiment of the tension adjusting device which concerns on this invention Sectional drawing which expands and shows a part of FIG. Sectional view along line III-III in FIG. Sectional drawing which shows 2nd Embodiment of the tension adjustment apparatus which concerns on this invention Sectional drawing which shows 3rd Embodiment of the tension adjustment apparatus which concerns on this invention Sectional drawing which shows 4th Embodiment of the tension adjustment apparatus which concerns on this invention (I) is sectional drawing which shows 5th Embodiment of the tension adjusting device based on this invention, (II) is a vertical side view of (I) Sectional drawing which shows 6th Embodiment of the tension adjusting device which concerns on this invention Sectional drawing which shows 7th Embodiment of the tension adjusting device which concerns on this invention The graph which shows the change of the fluctuating load which acts on the rod of an auto tensioner at the time of the drive of a V type 6 cylinder engine (I) is a graph showing a change in load acting on the rod of the auto tensioner when driving the V-type 6-cylinder engine and a displacement of the tension pulley, and (II) is a load acting on the rod of the auto tensioner when driving the in-line 4-cylinder engine. Graph showing the change of the rod and the displacement of the rod

Explanation of symbols

1 Crankshaft 2 Camshaft 5 Timing belt (winding transmission member)
6 Tension pulley 7 Pulley arm 10 Auto tensioner 11 Body 15 Rod 16 Tension adjustment spring 17 Hydraulic damper 30 Thrust addition device 31 Second cylinder chamber 32 Piston 32a Rod 33 Lower chamber 34 Upper chamber 35 Inlet 36 Outlet 40 Tension pulley 41 Pulley support 45 Tension adjusting spring 46 Hydraulic damper 50 Body 51 Cylinder chamber 52 Lower chamber 53 Upper chamber 54 Piston 54a Rod 56 Inlet 57 Outlet 58 Pulley arm 61 Actuator 62 Rod

Claims (6)

  Pushing force of the auto tensioner on the swingable pulley arm that contacts the rotatable tension pulley to the endless winding transmission member that transmits the rotation of the crankshaft to the camshaft and moves the tension pulley relative to the winding transmission member A tension pulley is wound around and pressed against the transmission member, and the auto tensioner is loaded on the rod, a rod whose tip is in contact with the pulley arm, a tension adjusting spring that urges the rod toward the pulley arm, and the rod In a tension adjusting device for a wound transmission member having a hydraulic damper that cushions an axial pushing force, when switching from low rotation during idling of the engine to practical rotation for running the vehicle, or at maximum load The thrust can be changed arbitrarily so that the minimum load at the resonance point and peak load does not fall below zero. Tension adjusting device of the belt-driven member, characterized in that the tension pulley by adding thrust to said pulley arm is provided with a thrust additional device for urging the pulley arm in a direction for pressing the belt-driven member.   The tension adjusting device for a winding transmission member according to claim 1, wherein the thrust adding device is provided in parallel with the auto tensioner.   The tension adjusting device for a winding transmission member according to claim 1, wherein the thrust adding device is provided in series with an auto tensioner.   The thrust adding device is slidably incorporated in a cylinder chamber formed in the body into a piston that partitions the inside into a lower chamber and an upper chamber, and an inlet is provided that communicates with the lower chamber and is supplied with hydraulic pressure. 4. The tension adjusting device for a wound transmission member according to claim 1, further comprising an outlet communicating with the upper chamber and a rod for pressing a pulley arm on the piston.   The tension adjusting member of the winding transmission member according to claim 1 or 2, wherein the thrust adding device is a solenoid having a push rod.   Pushing force of the auto tensioner on the swingable pulley arm that contacts the rotatable tension pulley to the endless winding transmission member that transmits the rotation of the crankshaft to the camshaft and moves the tension pulley relative to the winding transmission member A tension pulley is wound around and pressed against the transmission member, and the auto tensioner is loaded on the rod, a rod whose tip is in contact with the pulley arm, a tension adjusting spring that urges the rod toward the pulley arm, and the rod In a tension adjusting device for a winding transmission member having a hydraulic damper for buffering an axial pushing force, the auto tensioner is supported in a swingable manner, and the vehicle is driven from a low rotation during idling of the engine. When switching to operation, the resonance point at the maximum load or the minimum load at the peak load Wrapping transmission, characterized in that an actuator is provided for swinging the auto tensioner in a direction in which the contact position of the rod with respect to the pulley arm is away from the swing center of the pulley arm so that the thrust can be arbitrarily changed so as not to fall below Tension adjusting device for members.

Images