JP2005083514A - Tension adjustment method for accessory driving belt and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tension adjustment method for an accessory driving belt and its device having simple construction for preventing the slippage and sagging of the belt and reducing friction by securing the tension of the belt when starting and normally operating an engine. <P>SOLUTION: The method comprises a first step of holding a first auto tensioner 14a abutting on the belt 6 on the slack side of a driving pulley 2 in a locked condition and holding a second auto tensioner 14b abutting on the belt 6 on the slack side of a starting pulley in a free condition when driving the driving pulley 2 with the starting pulley 1 and a second step of holding the second auto tensioner 14b in a locked condition and holding the first auto tensioner 14a in a free condition when driving the starting pulley 1 with the driving pulley 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an auxiliary machine drive belt tension adjusting method and an auxiliary machine drive belt tension adjusting apparatus suitable for a belt type starter generator system.

  In recent years, a starter generator that has both a starter function for starting the engine and an alternator (generator) function for generating electricity by the driving force of the engine has been provided, and this starter generator is connected to the engine crank pulley via a belt Has been developed. In other words, the starter generator, the engine and the auxiliary machine are arranged so that power can be transmitted via the belt so that the starter generator drives the engine when the engine starts, and after the engine starts, that is, during normal engine operation. Conversely, the engine is configured to drive a starter generator and auxiliary equipment.

  In such an auxiliary machine drive system using a belt, an auto tensioner is provided in order to keep constant the belt tension which changes according to the operation state of the starter generator, the engine, and the auxiliary machine. This auto tensioner presses the belt according to the tension of the belt, thereby preventing the belt from sagging and preventing excessive tension from acting on the belt, and always ensuring a constant belt tension. Is.

  In the accessory drive system using the belt equipped with the auto tensioner described above, the belt tension should be set as low as possible without belt slippage in order to reduce the friction of the entire accessory drive system during normal engine operation. However, if the belt tension is too small, belt slippage may occur. In particular, when such a belt slip occurs at the start of the engine, the starter generator cannot start the engine. Therefore, when the starter generator starts the engine, the starter generator is pulled (on the upstream side of the starter generator). It is desirable that a predetermined belt tension (hereinafter also referred to as a necessary initial tension) is set to the belt.

  In order to solve such a problem, a lock type auto tensioner configured to fix a pressing position of a member that presses the belt of the auto tensioner at an arbitrary position has been developed. For example, during normal engine operation, the belt functions as a general auto tensioner so as to keep the tension acting on the belt constant, and immediately before the engine is stopped, the pressing position of the member that presses the belt is fixed (locked) as it is. At the time of restarting the engine after that, there is one that is arranged to hold the fixed state immediately before the engine is stopped and is arranged on the belt on the pulling side of the starter generator (for example, the lock type of Mubea) Auto tensioner). According to such a technique, since the pressing position of the member that presses the belt is fixed when the engine is started, the necessary initial tension is ensured to prevent the belt from slipping, and the engine can be started reliably. Since the pressing position of the member that presses the belt is adjusted after startup, a constant tension can be maintained.

On the other hand, Patent Document 1 discloses a lock type auto tensioner configured such that a pressing position of a member that presses a belt can be fixed at a predetermined position set in advance. In other words, the auto tensioner arranged to press the belt on the pulling side (upstream side) of the starter generator so that a tension greater than the belt tension during normal engine operation is applied when the engine is started. The (belt tension adjusting device) is configured to move and fix the position of the belt tension adjusting pulley to a predetermined position. Even with this technology, when starting the engine, a higher belt tension is set than after starting the engine to prevent belt slipping, and the engine can be started reliably. After starting the engine, the belt tension is set lower than at starting. Thus, friction can be reduced.
JP 2003-172415 A

  By the way, in the accessory drive system using the belt provided with the above-described auto tensioner, when the engine is driven by the starter generator, the belt is most slackened on the rotation direction side of the starter generator (that is, downstream of the starter generator). When the starter generator is driven by the engine, the most slack is likely to occur in the belt located on the engine rotation direction side (corresponding to the downstream side of the engine, that is, the upstream side of the starter generator). Smoldering. The auto tensioner is preferably arranged in a place where the most sag is likely to occur. However, in the above-described lock type auto tensioner and the lock type auto tensioner described in Patent Document 1, the auto tensioner is disposed on the upstream side of the starter generator. From the viewpoint of preventing belt sagging, it is possible to effectively prevent belt sagging when the engine is driven by the engine, but the engine is driven by the starter generator. In this case, it is difficult to prevent the slack of the belt that is likely to occur.

  The present invention has been devised in view of such problems, and with a simple configuration, the belt tension is ensured to prevent slippage at the time of engine start and during normal operation of the engine, and slack that can occur in the belt. It is an object of the present invention to provide an auxiliary machine drive belt tension adjusting method and an auxiliary machine drive belt tension adjusting apparatus that can prevent friction and reduce friction.

  In order to achieve the above object, a tension adjusting method for an auxiliary machine driving belt according to the present invention (Claim 1) includes a driving pulley mounted on a driving shaft of a vehicle engine and a starting pulley mounted on a starter of the engine. A belt that is wound around the drive pulley and the start pulley and transmits a drive force between the pulleys, and the belt on the loose side of the drive pulley when the start pulley is driven by the drive pulley A first auto tensioner provided in contact with the first pulley, and a second auto tensioner provided in contact with the belt on the loose side of the starting pulley when the driving pulley is driven by the starting pulley. Both the first auto tensioner and the second auto tensioner allow a relative position change with respect to the running position of the belt and keep the belt tension at a predetermined tension. It is configured as a lock type auto tensioner that can be switched between a locked state that restricts a relative position change with respect to the running position of the belt, and when the driving pulley is driven by the start pulley, the first auto tensioner is A first step of holding the second auto tensioner in the free state while holding the second auto tensioner; and holding the second auto tensioner in the locked state during driving of the starting pulley by the driving pulley; And a second step of holding the first auto tensioner in the free state.

  Further, the first auto tensioner prevents the pulley from slipping together with the predetermined tension held by the first auto tensioner in the free state and the predetermined tension held by the second auto tensioner in the free state. It is preferable to set the magnitude of the larger one of the minimum first predetermined tension that can be performed and the minimum second predetermined tension that the second auto tensioner can prevent the pulley from slipping. Item 2).

  In addition, a tension adjusting device for an auxiliary machine drive belt according to the present invention (Claim 3) includes a drive pulley attached to a drive shaft of a vehicle engine, a start pulley attached to a starter of the engine, and an auxiliary machine. A mounted auxiliary pulley, a belt that is wound around the driving pulley, the starting pulley, and the auxiliary pulley and transmits a driving force between the pulleys; and when the starting pulley is driven by the driving pulley A first auto tensioner provided in contact with the belt on the loose side of the drive pulley in contact with the belt on the loose side of the start pulley when the drive pulley is driven by the start pulley. A second auto tensioner provided, and both the first auto tensioner and the second auto tensioner allow a relative positional change with respect to the running position of the belt to set a predetermined tension of the belt. It is configured as a lock-type auto tensioner that can be switched between a free state that is held by force and a locked state that restricts a relative position change with respect to the travel position of the belt, and when the drive pulley is driven by the start pulley A first step of holding the first autotensioner in the locked state and holding the second autotensioner in the free state, and driving the starting pulley by the drive pulley, the second autotensioner A second step of holding the first auto tensioner in the free state, and a predetermined tension held by the first auto tensioner in the free state, and Along with the predetermined tension held by the second auto tensioner, the first auto tensioner causes the pulley to slip. Of the minimum first predetermined tension that can be stopped and the minimum second predetermined tension that the second auto tensioner can prevent the pulley from slipping, the larger tension is set. Yes.

  A tension adjusting device for an auxiliary machine drive belt according to the present invention (Claim 4) includes a drive pulley attached to a drive shaft of an engine of a vehicle, a start pulley attached to a starter of the engine, the drive pulley, A belt that is wound around the start pulley and transmits a driving force between the pulleys, and a first belt provided in contact with the belt on the loose side of the drive pulley when the start pulley is driven by the drive pulley. An auto tensioner and a second auto tensioner provided in contact with the belt on the loose side of the start pulley when the drive pulley is driven by the start pulley, the first auto tensioner and the second auto tensioner Each of the tensioners allows a relative position change with respect to the running position of the belt and keeps the belt tension at a predetermined tension. A tension adjusting device for an auxiliary machine drive belt configured as a lock type auto tensioner that can be switched between a locked state that restricts a relative position change, wherein the first auto tensioner has a free state and a locked state. First auto tensioner control means for switching, and second auto tensioner control means for switching between the free state and the locked state of the second auto tensioner. The first auto tensioner is controlled by the first auto tensioner control means. The locked state is maintained when the drive pulley is driven by the start pulley, and the free state is maintained when the start pulley is driven by the drive pulley, and the second auto tensioner controls the second auto tensioner. The locked state is maintained when the starting pulley is driven by the driving pulley. Both are characterized by the free state is held in driving of the drive pulley by the pulley above start moving.

  In addition, the first auto tensioner and the second auto tensioner both have a minimum first predetermined tension that the first auto tensioner can prevent the pulley from slipping in the free state, and the second auto tensioner Of the minimum second predetermined tension that can prevent the pulley from slipping, it is preferable that the larger tension is set as the predetermined tension to maintain the belt tension.

  In addition, a tension adjusting device for an auxiliary machine drive belt according to the present invention (Claim 6) includes a drive pulley attached to a drive shaft of a vehicle engine, a start pulley attached to a starter of the engine, and an auxiliary machine. A mounted auxiliary pulley, a belt that is wound around the driving pulley, the starting pulley, and the auxiliary pulley and transmits a driving force between the pulleys; and when the starting pulley is driven by the driving pulley A first auto tensioner provided in contact with the belt on the slack side of the driving pulley in contact with the belt on the slack side of the starting pulley when the driving pulley is driven by the starting pulley. A second auto tensioner, and both the first auto tensioner and the second auto tensioner allow a relative position change with respect to the running position of the belt to allow a predetermined tension of the belt. A tension adjusting device for an accessory drive belt configured as a lock-type auto tensioner that can be switched between a free state to be held and a lock state that restricts a relative position change with respect to the belt running position, First auto tensioner control means for switching between a free state and a locked state of the first auto tensioner, and second auto tensioner control means for switching between a free state and a locked state of the second auto tensioner, the first auto tensioner The first auto tensioner control means holds the locked state when the driving pulley is driven by the starting pulley, and maintains the free state when the starting pulley is driven by the driving pulley. The second auto tensioner is driven by the drive pulley by the second auto tensioner control means. The locked state is maintained when the start pulley is driven, and the free state is maintained when the drive pulley is driven by the start pulley. Both the first auto tensioner and the second auto tensioner are free In the state, the first auto tensioner is larger than a minimum first predetermined tension that can prevent the pulley from slipping, and a minimum second predetermined tension that the second auto tensioner can prevent the pulley from slipping. The tension of the belt is maintained as the predetermined tension, and the tension of the belt is maintained.

  According to the tension adjusting method for an auxiliary machine driving belt and the tension adjusting device for an auxiliary machine driving belt according to the present invention, it is possible to prevent the belt from sagging when the starter generator is driven by the engine and to drive the engine by the starter generator. The belt can be prevented from sagging when the engine is started, the belt can be prevented from slipping when the engine is started, and the belt can be prevented from slipping when the starter generator (or auxiliary machine) is driven by the engine. Can do. Further, since the belt can be prevented from slipping with the minimum necessary tension, the friction of the belt can be reduced. (Claims 1 and 4).

  Further, according to the tension adjusting method for an auxiliary machine driving belt of the present invention and the tension adjusting device for an auxiliary machine driving belt of the present invention, the belt tension adjusted by the first auto tensioner and the belt tension adjusted by the second auto tensioner. Are set to the same value, it is possible to prevent the belt tension from being dispersed by alternately repeating the lock state and the free state, and each auto tensioner can be operated stably. 2, 3, 5, 6).

  An object of the present invention is to have a simple configuration, to ensure belt tension at the time of engine start and during normal operation of the engine to prevent slippage, prevent sagging that may occur in the belt, and reduce friction. In the lock-type auto tensioner with auto tensioners on the loose side of the drive pulley and the loose side of the start pulley, the free state and the locked state of each auto tensioner are changed according to the drive state of the engine and starter. Realized by switching.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a tension adjusting device for an accessory driving belt according to an embodiment of the present invention. FIG. 1 is a schematic configuration diagram showing the configuration of the tension adjusting device, and FIG. It is a figure which shows control of the auto tensioner concerning an adjusting device, (a) is a schematic diagram which shows control of the auto tensioner at the time of engine starting, (b) is a schematic diagram which shows control of the auto tensioner at the time of normal engine normal operation FIG. 3 is a flowchart for explaining the control of the auto tensioner according to the tension adjusting device.

In this embodiment, the vehicle to which the present invention is applied automatically stops the engine when a predetermined engine stop condition is satisfied, and automatically operates when the predetermined engine restart condition is satisfied after the engine is automatically stopped. The vehicle is configured as a so-called idle stop vehicle that restarts.
As shown in FIG. 1, the auxiliary device drive belt tension adjusting device is attached to a crank pulley (drive pulley) 2 attached to a drive shaft 12 of an engine 10 and a starter generator (starter) 11 of the engine 10. As an auxiliary pulley attached to a starter pulley 1, an A / C pulley 3 as an auxiliary pulley attached to an air conditioner compressor 13 provided as an auxiliary machine, and a water pump 18 similarly provided as an auxiliary machine W / P pulley 8 and belt 6 which is wound around these starting pulley 1, crank pulley 2, A / C pulley 3 and W / P pulley 8 to transmit the driving force between each pulley, and starting Two auto tensioners 14 provided between the pulley 1 and the crank pulley 2 and capable of holding the belt 6 at a predetermined tension by contacting the belt 6 and the belt An idler pulley 5 for adjusting the winding length of each pulley, the starter generator 11 is configured by a ECU (control means) 7 for controlling the auto tensioner 14 and the engine 10.

The two auto tensioners 14 are provided on the upstream side of the crank pulley 2. The first auto tensioner 14 a includes a first roller 4 a that presses the belt 6 between the start pulley 1 and the crank pulley 2. And a second auto tensioner 14b provided with a second roller 4b that presses the belt 6 between the W / P pulley 8 and the A / C pulley 3. Yes.
In this embodiment, each pulley and belt 6 are configured to rotate in the direction of the arrow shown in FIG. 1, and the starting pulley 1, crank pulley 2, A / C pulley 3 and second roller 4b are In the clockwise direction (clockwise), the first roller 4a, idler pulley 5 and W / P pulley 8 rotate in the counterclockwise direction (counterclockwise) so that each functions.

  The starter generator 11 has a function as a starter that restarts the engine 10 from the idle stop state, and also has a function as an alternator that is driven by the engine 10 to generate electric power. It also has a function as a power generation pulley. When the engine 10 is restarted, the starter generator 11 rotates the start pulley 1 and the driving force is transmitted to the crank pulley 2 and the drive shaft 12 via the belt 6 to restart the engine 10 (or Start).

Once the engine 10 has been started, the engine 10 rotates the start pulley 1 via the belt 6 to drive the starter generator 11 so that the starter generator 11 can generate power. The starter generator 11 not only generates electric power according to the electric load of the vehicle, such as driving the on-vehicle air conditioner and lighting the headlamp, but also generates electric power even when there is no electric load of the vehicle under the control of the ECU 7. Can be actively loaded. Note that, as described above, positively applying a load to the engine 10 by the starter generator 11 is referred to as braking.
Further, the engine 10 can drive the air conditioner compressor 13 and the water pump 18 by rotating the A / C pulley 3 and the W / P pulley 8 as auxiliary machinery pulleys via the belt 6.

  The air conditioner compressor 13 is provided as an auxiliary machine driven by the engine 10. The air conditioner compressor 13 is a compressor of a general on-vehicle air conditioner. When an air conditioner switch (not shown) is turned on by the driver while the engine 10 is being driven, the air conditioner compressor 13 is controlled based on a control signal from the ECU 7. The compressor 13 starts operation, and the in-vehicle air conditioner is activated. In the present embodiment, the operation can be started regardless of the operation of the air conditioner switch by the driver, and a load can be applied to the engine 10.

Similarly, the water pump 18 is provided as an auxiliary machine driven by the engine 10. The water pump 18 is provided as a water pump for circulating cooling water of a general water-cooled engine.
The idler pulley 5 is provided between the starting pulley 1 and the A / C pulley 3 and is provided as a pulley for securing the winding length of the belt 6 wound around these pulleys. Yes.

  The first auto tensioner 14a includes a first roller 4a that is provided between the crank pulley 2 and the starting pulley 1 and abuts against the belt 6, and the first roller 4a presses the belt 6 The tension of the belt 6 can be adjusted. The second auto tensioner 14b includes a second roller 4b that is provided between the W / P pulley 8 and the A / C pulley 3 and contacts the belt 6. The second roller 4b is also a belt. 6 is pressed so that the tension of the belt 6 can be adjusted.

  The first roller 4a and the second roller 4b are in a free state in which the belt 6 is kept at a predetermined tension while allowing a relative position change with respect to the running position of the belt 6 according to the tension of the belt 6. And a locked state that restricts the relative position change of the belt 6 with respect to the running position can be switched, and switching between the free state and the locked state can be performed independently by the ECU 7. It has become.

When the first roller 4a is in a free state, the first auto tensioner 14a works so that the tension of the belt 6 between the pulley 1 and the crank pulley 2 at the start is maintained at a predetermined tension _Tf1 , and the first roller 4a The relative position with respect to the belt 6 is adjusted.
When the first roller 4a is in the locked state, the relative position of the first roller 4a with respect to the belt 6 is fixed at the position immediately before the locked state. Further, once the first roller 4a is held in the locked state, the first roller 4a is not changed in relative position with respect to the belt 6 until the next free state, and the engine is automatically stopped. The locked state of the first roller 4a is maintained even in the state (that is, the idle stop state).

The same applies to the second roller 4b. When the second roller 4b is in a free state, the tension of the belt 6 between the W / P pulley 8 and the A / C pulley 3 is maintained at a predetermined tension _Tf1. In this way, the second auto tensioner 14b works to adjust the relative position of the second roller 4b with respect to the belt 6.
In this embodiment, the predetermined tension T _f1 in the free state of the first roller 4a and the second roller 4b is the minimum tension that can prevent the first auto tensioner 14a from slipping each pulley, and the second tension T _f1 in the present embodiment. Of the minimum tension that can prevent the slippage of each pulley by the auto tensioner 14b, the larger tension is set.

  When the second roller 4b is locked, the relative position of the second roller 4b with respect to the belt 6 changes. When the second roller 4b is locked, the relative position of the second roller 4b with respect to the belt 6 is changed until the next free state. It is supposed not to let you. The locked state of the second roller 4b is maintained even when the engine is automatically stopped (idle stop state).

  Next, the contents of control by the ECU 7 will be described. The ECU 7 includes three control units as shown in FIG. That is, a first auto tensioner control section (first auto tensioner control means) 7a that controls switching of the operating state of the first auto tensioner 14a and a second auto tensioner control section that controls switching of the operating state of the second auto tensioner 14b ( (Second auto tensioner control means) 7b and a starter generator control section (starter control means) 7c for controlling the operation of the starter generator 11.

The ECU 7 is connected to an engine speed sensor (not shown) for detecting the speed of the engine 10 and an IG switch 9 for detecting the position of an ignition (IG) key. The EUC 7 can determine the operating state of the engine based on information from the engine speed sensor. The IG switch 9 in the present embodiment is provided as a general IG switch that can detect four positions of off / accessory / on / start.
The ECU 7 is also provided with an idle stop control unit 7d that outputs an idle stop signal to the engine 10 to stop the engine 10 or outputs an engine start signal to the starter generator 11 to restart the engine 10. ing.
Further, in the present embodiment, when the engine 10 is started by the operation of the IG key by the driver, the engine 10 is also driven by a starter motor (not shown) to start and is configured to include the above-described general drive system. The starter generator 11 is mainly used as a drive source at the time of restart after automatic stop of the engine by idle stop control.

As shown in FIG. 2A, when the engine 10 is restarted after automatic stop (idle stop) (that is, when the engine 10 is driven by the starter generator 11), the first auto tensioner control unit 7a The first roller 4a is held in a locked state, and the second roller 4b is set in a free state by the second auto tensioner control unit 7b. And thereby W / P pulley 8 and the second auto-tensioner 14b as the tension of the belt 6 between the A / C pulley 3 is maintained at a predetermined tension T _f1 is operated.

Further, as shown in FIG. 2B, during the normal operation of the engine 10 (that is, when the starter generator 11 and the auxiliary machine are driven by the engine 10), the first auto tensioner control unit 7a performs the first roller. 4a is set to the free state, and the second roller 4b is held in the locked state by the second auto tensioner control section 7b. As a result, the first auto tensioner 14a operates so that the belt tension between the start pulley 1 and the crank pulley 2 is maintained at a predetermined tension T _f1 .

Since the tension adjusting device for an auxiliary machine driving belt according to the embodiment of the present invention is configured as described above, its operation will be described as follows.
In the ECU 7 of the tension adjusting device for the accessory drive belt, control is performed based on the flowchart shown in FIG. This control is always processed in the ECU 7 when the driver operates the IG key and the IG switch 8 is on.

  First, in step S10, when the IG key is operated by the driver, the second roller 4b of the second auto tensioner 14b is held in the locked state by the second auto tensioner controller 7b. By such control, a desired belt tension is applied when the engine 10 is driven by a starter motor (not shown). At this time, in the present embodiment, the first roller 4a of the first auto tensioner 14a is set to a free state and functions as a normal auto tensioner.

Next, in step S20, it is determined whether or not the engine 10 has been started by a starter motor (not shown). For example, it is determined based on whether or not the engine speed N _e is equal to or greater than a predetermined value N _e0 (N _e ≧ N _e0 ). Here, if N _e ≧ N _e0 , it is determined that the start of the engine 10 has been completed, and the process proceeds to step S30 to perform normal engine operation. However, if N _e <N _e0 , It is determined that the start is not yet completed, and the determination in this step is repeatedly executed until N _e ≧ N _e0 . The control from step S10 to step S20 is control at the time of engine start by operation of the IG switch 9, and control related to automatic stop and restart of the engine by idle stop control is controlled by the flow after step S30.

  Next, in step S40, it is determined whether an engine stop condition is satisfied. The engine automatic stop condition is a condition for determining whether or not the above-described automatic stop (idle stop) of the engine 10 is performed. For example, the accelerator opening is less than a predetermined value (a minute value close to 0). If a condition such that the vehicle speed is less than a predetermined speed (a minute speed close to 0) is satisfied, it is determined that the engine stop condition is satisfied, the process proceeds to step S50, and the engine stop 10d is sent to the engine 10 by the idle stop control unit 7d. The fuel supply is cut and the engine 10 automatically stops (idle stop). If the engine stop condition is not satisfied, the process returns to step S30 and the normal operation of the engine 10 is continued.

  After the engine 10 is automatically stopped, the routine proceeds to step S60, where it is determined whether or not an engine restart condition is satisfied. The engine restart condition is a condition for determining whether or not the automatic restart after the automatic stop (idle stop) of the engine 10 is performed. For example, the accelerator pedal is depressed after the engine 10 is automatically stopped. It is determined by the presence or absence of. Here, when the restart condition of the engine 10 is satisfied, the process proceeds to step S70, and the first auto tensioner controller 7a holds the first roller 4a of the first auto tensioner 14a in the locked state, and the second condition. The second roller 4b of the second auto tensioner 14b is set to a free state by the auto tensioner control unit 7b. In step S80, the starter generator controller 7c operates the starter generator 11 as a starter to start the engine. If the engine restart condition is not satisfied, it is determined that the engine 10 is not started (that is, the stopped state of the engine 10 is maintained as it is), the process returns to step S50, and the automatic stop state of the engine 10 is set. continue.

  That is, in the control from step S60 to step S80, when the crank pulley 2 is driven by the starting pulley 1, the first auto tensioner 14a is held in a locked state to secure the tension of the belt 6 on the upstream side of the starter generator 11. The second auto tensioner 14b is set in a free state to act as a control for preventing the slack of the belt 6 on the downstream side of the starter generator 11, and corresponds to the first step.

After the starter generator 11 starts the engine 10 in step S80, the process proceeds to step S90, and it is determined whether the start of the engine 10 is completed. This is set as a condition for bringing the first roller 4a held in the locked state in order to secure the necessary initial tension of the belt 6 required at the time of starting the engine 10, for example, the engine 10 It is determined by whether or not the rotational speed N _e is equal to or greater than a predetermined value N _e1 (N _e ≧ N _e1 ). Here, if N _e ≧ N _e1 , it is determined that the engine has been started, and the routine proceeds to step S100 where the first auto tensioner controller 7a is in the free state of the first roller 4a of the first auto tensioner 14a. And the second roller 4b of the second auto tensioner 14b is held in the locked state by the second auto tensioner controller 7b. Then, the process returns to step S30 and the engine 10 is normally operated.

If N _e <N _e1 , it is determined that the engine 10 has not yet been started, and the determination in this step is repeatedly executed until N _e ≧ N _e1 .
That is, the control from step S90 to step S100 is performed while the start pulley 1 is driven by the crank pulley 2 to keep the first auto tensioner 14b in a free state and prevent the belt 6 on the downstream side of the crank pulley 2 from sagging. The second auto tensioner 14a is held in the locked state and acts as a control for securing the tension of the belt 6 on the upstream side of the crank pulley 2, and corresponds to the second step.

The tension adjusting device for the accessory drive belt according to the present embodiment has the following effects by the control action as described above.
First, in a normal engine operating state, the first auto tensioner controller 7a of the ECU 7 sets the first roller 4a of the first auto tensioner 14a to a free state, and the tension of the belt 6 on the downstream side of the crank pulley 2 is set to a predetermined value. The tension is maintained to be T _f1 . Therefore, sagging on the downstream side of the crank pulley 2 is prevented, and appropriate tension can be applied to the belt 6.

  At this time, the locked state of the second roller 4b of the second auto tensioner 14b is maintained by the second auto tensioner controller 7b, and the tension of the belt 6 on the upstream side of the crank pulley 2 is secured. Therefore, the start pulley 1 and the auxiliary pulley are prevented from slipping during normal engine operation, and the engine 10 can reliably drive the starter generator 11 and the auxiliary machinery.

Further, since the second roller 4b secures the belt tension of the belt 6 in the locked state, compared with the case where the second roller 4b is not present (or compared with the case where the second roller 4b is in the free state). ), The predetermined tension T _f1 to be held by the first roller 4a can be reduced by the amount of belt tension borne by the second roller 4b. Therefore, the set tension of the auto tensioner can be reduced as compared with the conventional lock type auto tensioner, and the friction of the belt 6 can be reduced.

  Next, when the engine restart condition is satisfied after the engine is automatically stopped (that is, idling stop), the first auto tensioner control unit 7a causes the first roller 4a of the first auto tensioner 14a to remain at the position immediately before the engine is stopped. It is kept locked. Therefore, it is possible to prevent the belt from slipping when the engine is started. In addition, the engine can be reliably started.

At this time, the second auto tensioner control unit 7b sets the second roller 4b of the second auto tensioner 14b to a free state so that the tension of the belt 6 on the downstream side of the starter generator 11 becomes the predetermined tension T _f1. Retained. Therefore, sagging of the belt 6 on the downstream side of the starter generator 11 is prevented, and appropriate tension can be applied to the belt 6.

Further, since the first roller 4a is locked and the belt tension of the belt 6 is secured, the predetermined tension T _f1 that the second roller 4b should hold is equal to the amount of belt tension borne by the first roller 4a. Can be reduced. Therefore, the set tension of the auto tensioner can be reduced as compared with the conventional lock type auto tensioner, and the friction of the belt 6 can be reduced.

In addition, the set tensions of the first roller 4a and the second roller 4b in the free state are both set to the larger value of the minimum tensions at which the respective auto tensioners can prevent the slippage of the pulleys. The belt tension can be prevented from being dispersed by alternately repeating the locked state and the free state of the first roller 4a and the second roller 4b while reliably preventing the belt from slipping. As described above, according to the present invention, it is not necessary to adjust the tension of the belt 6 by actively moving the roller 4 when starting the engine, the structure is simple, and the manufacturing cost is increased. Can be suppressed.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the set tension of the first roller 4a and the set tension of the second roller 4b in the free state are configured to have the same value, but the belt is held by each auto tensioner. The tension may be set to be the minimum tension that can prevent the belt from slipping by each auto tensioner.

  Further, for example, in the above-described embodiment, the average tension of the belt 6 that is required when starting the engine is increased by applying a load to the air conditioner compressor 13 and applying a brake to the starter generator 11 immediately before the engine is stopped. The required initial tension may be secured.

It is a typical block diagram which shows the structure of the tension adjustment apparatus of the auxiliary machine drive belt concerning embodiment of this invention. It is a figure which shows control of the auto tensioner of the tension adjustment apparatus of the auxiliary machine drive belt concerning embodiment of this invention, (a) is a schematic diagram which shows control of the auto tensioner at the time of engine starting, (b) is a normal engine It is a schematic diagram which shows control of the auto tensioner at the time of normal driving | operation. It is a flowchart which shows the adjustment method of the belt tension concerning the tension adjusting device of the auxiliary machine drive belt concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Start pulley 2 Crank pulley 3 A / C pulley 4a 1st roller 4b 2nd roller 5 Idler pulley 6 Belt 7 ECU
7a First auto tensioner control section (first auto tensioner control means)
7b Second auto tensioner control section (second auto tensioner control means)
7c Starter generator control unit 7d Idle stop control means 8 W / P pulley 9 IG switch 10 Engine 11 Starter generator 12 Drive shaft 13 Air conditioner compressor 14a First auto tensioner 14b Second auto tensioner 18 Water pump

Claims (6)

A drive pulley mounted on the drive shaft of the vehicle engine;
A starting pulley mounted on the starter of the engine;
A belt wound around the drive pulley and the start pulley and transmitting a drive force between the pulleys;
A first auto tensioner provided in contact with the belt on the loose side of the drive pulley when the start pulley is driven by the drive pulley;
A second auto tensioner provided in contact with the belt on the loose side of the starting pulley when the driving pulley is driven by the starting pulley;
Both the first auto tensioner and the second auto tensioner allow a relative position change with respect to the running position of the belt and keep the tension of the belt at a predetermined tension; It is configured as a lock-type auto tensioner that can be switched between a locked state that restricts relative position changes,
A first step of holding the first auto tensioner in the locked state and holding the second auto tensioner in the free state when the driving pulley is driven by the start pulley;
A second step of holding the second auto tensioner in the locked state and holding the first auto tensioner in the free state when the start pulley is driven by the drive pulley. , Tension adjustment method of auxiliary machine drive belt. Both the predetermined tension held by the first auto tensioner in the free state and the predetermined tension held by the second auto tensioner in the free state,
A first predetermined tension that the first auto tensioner can prevent the pulley from slipping; and
2. The accessory drive belt according to claim 1, wherein the second auto tensioner is set to a larger one of the minimum second predetermined tensions capable of preventing the pulley from slipping. Tension adjustment method. A drive pulley mounted on the drive shaft of the vehicle engine;
A starting pulley mounted on the starter of the engine;
An auxiliary pulley mounted on the auxiliary machine,
A belt that is wound around the driving pulley, the starting pulley, and the auxiliary pulley and transmits a driving force between the pulleys;
A first auto tensioner provided in contact with the belt on the loose side of the drive pulley when the start pulley is driven by the drive pulley;
A second auto tensioner provided in contact with the belt on the loose side of the starting pulley when the driving pulley is driven by the starting pulley;
Both the first auto tensioner and the second auto tensioner allow a relative position change with respect to the running position of the belt and keep the tension of the belt at a predetermined tension; It is configured as a lock-type auto tensioner that can be switched between a locked state that restricts relative position changes,
A first step of holding the first auto tensioner in the locked state and holding the second auto tensioner in the free state when the driving pulley is driven by the start pulley;
A second step of holding the second auto tensioner in the locked state and holding the first auto tensioner in the free state when driving the starting pulley by the drive pulley;
Both the predetermined tension held by the first auto tensioner in the free state and the predetermined tension held by the second auto tensioner in the free state,
A first predetermined tension that the first auto tensioner can prevent the pulley from slipping; and
A tension adjusting method for an auxiliary machine drive belt, wherein the second auto tensioner is set to a larger one of the minimum second predetermined tensions capable of preventing the pulley from slipping. A drive pulley mounted on the drive shaft of the vehicle engine;
A starting pulley mounted on the starter of the engine;
A belt wound around the drive pulley and the start pulley and transmitting a drive force between the pulleys;
A first auto tensioner provided in contact with the belt on the loose side of the drive pulley when the start pulley is driven by the drive pulley;
A second auto tensioner provided in contact with the belt on the loose side of the start pulley when the drive pulley is driven by the start pulley;
Both the first auto tensioner and the second auto tensioner allow a relative position change with respect to the running position of the belt and keep the tension of the belt at a predetermined tension; A tension adjusting device for an auxiliary machine drive belt configured as a lock type auto tensioner that can be switched between a locked state that restricts relative position change,
First auto tensioner control means for switching between a free state and a locked state of the first auto tensioner;
A second auto tensioner control means for switching between a free state and a locked state of the second auto tensioner;
The first auto tensioner is held in the locked state when the drive pulley is driven by the start pulley by the first auto tensioner control means, and is in the free state when the start pulley is driven by the drive pulley. Is retained,
The second auto tensioner is held in the locked state when the start pulley is driven by the drive pulley by the second auto tensioner control means, and is in the free state when the drive pulley is driven by the start pulley. A tension adjusting device for an auxiliary machine drive belt, wherein The first auto tensioner and the second auto tensioner are both in the free state.
A first predetermined tension that the first auto tensioner can prevent the pulley from slipping; and
5. The belt tension is maintained by using the larger second tension as the second predetermined tension that can prevent the pulley from slipping by the second auto tensioner as the predetermined tension. A tension adjusting device for an accessory driving belt as described. A drive pulley mounted on the drive shaft of the vehicle engine;
A starting pulley mounted on the starter of the engine;
An auxiliary pulley mounted on the auxiliary machine,
A belt that is wound around the driving pulley, the starting pulley, and the auxiliary pulley and transmits a driving force between the pulleys;
A first auto tensioner provided in contact with the belt on the loose side of the drive pulley when the start pulley is driven by the drive pulley;
A second auto tensioner provided in contact with the belt on the loose side of the start pulley when the drive pulley is driven by the start pulley;
Both the first auto tensioner and the second auto tensioner allow a relative position change with respect to the running position of the belt and keep the tension of the belt at a predetermined tension; A tension adjusting device for an auxiliary machine drive belt configured as a lock type auto tensioner that can be switched between a locked state that restricts relative position change,
First auto tensioner control means for switching between a free state and a locked state of the first auto tensioner;
A second auto tensioner control means for switching between a free state and a locked state of the second auto tensioner;
The first auto tensioner is held in the locked state when the drive pulley is driven by the start pulley by the first auto tensioner control means, and is in the free state when the start pulley is driven by the drive pulley. Is retained,
The second auto tensioner is held in the locked state when the start pulley is driven by the drive pulley by the second auto tensioner control means, and is in the free state when the drive pulley is driven by the start pulley. Is retained,
The first auto tensioner and the second auto tensioner are both in the free state.
A first predetermined tension that the first auto tensioner can prevent the pulley from slipping; and
An auxiliary machine drive characterized in that the second auto tensioner holds the belt tension with the larger tension of the minimum second predetermined tensions capable of preventing slippage of the pulley as the predetermined tension. Belt tension adjustment device.

Images