JP2017141921A - Auxiliary machine drive belt tension adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auxiliary machine drive belt tension adjustment device capable of reducing a loss of an auxiliary machine drive system in which a driving side and a driven side are interchanged.SOLUTION: An auxiliary machine drive belt tension adjustment device 10 includes: a first roller 11 which applies a tension to a delivery section from a second pulley 2 to a first pulley 1 of a belt 3 which transmits the driving force in both directions from one to the other between the first pulley 1 and the second pulley 2; a second roller 12 which applies a tension to the delivery section from the first pulley 1 to the second pulley 2 of the belt 3; an arm 13 which supports the first roller 11 and the second roller 12 so as to be swingable around a rotation axis AX of the second pulley 2 as a revolving axis; a plurality of first elastic members 15a1, 15b1, 15c1 which apply an urging force in a direction perpendicular to a rotation axis BX of the first roller 11; and a plurality of second elastic members 15a2, 15b2, and 15c2 which apply an urging force in a direction perpendicular to a rotation axis CX of the second roller 12.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an accessory drive belt tension adjusting device.

  In recent years, demands for reducing the environmental load of automobiles are increasing, and there is a demand for stricter fuel consumption regulations (reduction of CO2 emissions). In response to such environmental conservation and resource saving demands, there is an increasing need for items that improve fuel consumption, and idling stop mechanisms are being installed and hybridized. In automobile internal combustion engines, a belt drive system is driven by mechanically connecting auxiliary machinery such as water pumps, compressors, and radiator fans required to operate the main engine and air conditioner with an auxiliary belt. The auxiliary drive belt system (hereinafter referred to as “auxiliary drive system”) is generally used. In the accessory drive system, a driving force is transmitted through an accessory belt wound around a crank pulley that is a main machine pulley and each accessory pulley. In this auxiliary machine drive system, there is an increasing need for loss reduction.

  In the auxiliary drive system that transmits the driving force by the belt, it is necessary to apply tension to the belt so that slip does not occur between each pulley and the belt. It is common to use. This tensioner has a function of keeping the tension of the belt in a section provided with the tensioner constant. The tension applied to the belt increases on the side pulled by the drive pulley (hereinafter also referred to as “tension side”) and decreases on the side pushed by the drive pulley (hereinafter also referred to as “relaxation side”). For example, when an alternator is provided as an auxiliary machine, an engine crank pulley that is a main machine pulley serves as a drive pulley, and an alternator pulley that serves as an auxiliary machine pulley serves as a driven pulley.

  The tension required to drive the belt increases in proportion to the transmission torque transmitted by the belt. That is, the appropriate value of the tension required to drive the belt varies depending on the load state of the driven pulley. Specifically, for example, the tension required to drive the belt changes according to the power generation amount of the alternator. When the power generation amount of the alternator is large and the transmission torque is large, the rotational resistance of the auxiliary pulley connected to the rotor of the alternator increases compared to the case where the power generation amount of the alternator is small and the transmission torque is small. In order to obtain torque, a larger tension is required than in the case of obtaining a small transmission torque. For this reason, for example, the tensioner is designed to prevent slippage between each pulley and the belt in advance even if the power generation amount of the alternator is maximized and the rotation resistance of the auxiliary pulley of the alternator is maximized. It is set so that a tension corresponding to the maximum power generation amount of the alternator can be obtained.

  Here, when a tensioner is provided on the tension side, even if the load on the driven pulley becomes maximum, the tension on the loose side where the tension applied to the belt is small causes slippage between each pulley and the belt. It is necessary to set a tension applied to the tension side of the belt (hereinafter referred to as “tension-side tension”) so that the tension does not occur. In other words, when the load on the driven pulley becomes maximum, it is necessary to set the tension side tension as the initial tension so as to obtain the slack side tension so that no slip or the like occurs between each pulley and the belt. In this way, when the tensioner is provided on the tension side, it is necessary to set the tension side tension required at the maximum load of the driven pulley as the initial tension, so it is not necessary when the load on the driven pulley is small and the transmission torque is small The tension is applied to the belt, and the transmission efficiency of the driving force by the belt is lowered.

  On the other hand, when a tensioner is provided on the slack side, the initial tension of the tension applied to the slack side of the belt (hereinafter referred to as “relaxation side tension”) may be the slack side tension required at the maximum load of the driven pulley. . That is, when the tensioner is provided in the accessory drive system, the initial tension applied to the belt can be made smaller when the tensioner is provided on the loose side of the belt than when the tensioner is provided on the belt tension side. For this reason, the tensioner is preferably provided on the loose side of the belt.

  In vehicles equipped with an idling stop mechanism and vehicles equipped with a hybrid system, ISG-equipped engines that employ a generator with starter function (ISG: Integrated Starter Generator) are becoming popular in place of conventional alternators. In such an ISG-equipped engine, the driving side and the driven side are switched between when the driving force by the engine is transmitted to the ISG for regeneration and when the driving force by the ISG is transmitted to perform engine start and driving assist. . That is, at the time of regeneration, the crank pulley becomes a drive pulley and the ISG pulley becomes a driven pulley, and at the time of engine start or drive assist, the ISG pulley becomes a drive pulley and the crank pulley becomes a driven pulley. In this way, in the accessory drive system in which the drive side and the driven side are switched, the tension side and the loose side are switched depending on which pulley is the drive pulley, and a transmission torque is generated in both directions. For this reason, for example, in Patent Document 1, two tensions supported by two tension arms that are pivotable relative to each other about a single pivot that is preferably arranged coaxially with the drive axis of the drive belt pulley. The roller is pressed from the outside to the back side of the belt by a tension spring to generate a tension force on the belt, and the two tension rollers swing around the pivot axis of the tension arm. Describes a belt tensioning device for a starter / generator in which one tension roller is pushed in a turning direction to apply tension to the loose belt by the other tension roller.

Japanese Patent No. 5634485

  However, the one described in Patent Document 1 has a structure in which an initial tension is applied to the belt by a tension spring, and it is necessary to set the tension side tension required when the transmission torque becomes maximum as the initial tension. In a region where the torque is small, excessive tension is applied to the belt, and the transmission efficiency of the driving force by the belt deteriorates.

  The present invention has been made in view of the above, and an object thereof is to provide an accessory drive belt tension adjusting device capable of reducing loss of an accessory drive system in which a drive side and a driven side are interchanged. To do.

  In order to solve the above-described problems and achieve the object, an auxiliary machine drive belt tension adjusting device is configured to provide a belt for transmitting a driving force bidirectionally from one to the other between a first pulley and a second pulley. A first roller that applies tension to a delivery section from two pulleys to the first pulley, a second roller that applies tension to a delivery section from the first pulley to the second pulley of the belt, and a second pulley Using a rotation axis as a turning axis, an arm that supports the first roller and the second roller in a swingable manner, and a plurality of second forces that apply a biasing force in a direction perpendicular to the rotation axis of the first roller. One elastic member, and a plurality of second elastic members for applying an urging force in a direction perpendicular to the rotation axis of the second roller.

  With the above configuration, the biasing force that each first elastic member gives to the first roller and the second roller is set by the spring constant of each first elastic member, and each second elastic member has the second spring member by the spring constant of each second elastic member. By setting the urging force that the elastic member applies to the first roller and the second roller, a slack side tension proportional to the transmission torque generated in both directions can be applied to the belt. As a result, it is possible to reduce the loss of the auxiliary drive system in which the drive side and the driven side are switched.

  In addition, as a desirable mode, a base member fixed in the circumferential direction with respect to the rotation axis of the second pulley is provided, and the plurality of first elastic members are respectively different from the predetermined positions of the base member. The plurality of second elastic members are respectively provided between the different predetermined positions of the base member and the rotation axis of the second roller. Is preferred.

  With the above configuration, the attachment position of each first elastic member to the base member and the attachment position of each second elastic member to the base member are set, and the slack side tension proportional to the transmission torque generated in both directions is applied to the belt. Can be given.

  Further, in the above configuration, the arm may be an elastic member that applies a biasing force in the swinging direction of the first roller and the second roller.

  ADVANTAGE OF THE INVENTION According to this invention, the auxiliary machine drive belt tension | tensile_strength adjustment apparatus which can reduce the loss of the auxiliary machine drive system with which a drive side and a driven side interchange is provided.

FIG. 1 is a diagram illustrating an example of an auxiliary machine drive system. FIG. 2 is a conceptual diagram showing the relationship between the transmission torque in the drive pulley and the tension on the tension side and the loose side. FIG. 3 is a diagram showing the relationship between transmission torque and tension in an accessory drive system in which a belt is wound around two pulleys. FIG. 4 is a structural conceptual diagram of an accessory drive system to which the accessory drive belt tension adjusting device according to the embodiment is applied. FIG. 5 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the embodiment when the first pulley generates driving force. FIG. 6 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the embodiment when the second pulley generates the driving force. FIG. 7 is a structural conceptual diagram of an accessory drive system to which an accessory drive belt tension adjusting device according to a comparative example is applied. FIG. 8 is a diagram illustrating a reference example in which the relationship between the spring force applied to the belt in the direction perpendicular to the belt by each spring that applies a biasing force to the central axis of the first pulley and the swing angle of the first pulley is simulated. FIG. 9 is a diagram showing a reference example in which the relationship between the spring force applied in the direction perpendicular to the traveling direction of the belt and the deflection angle of the first pulley by each spring applying a biasing force to the central axis of the first pulley is simulated. It is. FIG. 10 is a structural conceptual diagram of an accessory drive system to which an accessory drive belt tension adjusting device according to a modification of the embodiment is applied. FIG. 11 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the modification of the embodiment when the first pulley generates the driving force. FIG. 12 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the modification of the embodiment when the second pulley generates the driving force.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

(Embodiment)
FIG. 1 is a diagram illustrating an example of an auxiliary machine drive system. The auxiliary drive system shown in FIG. 1 is a machine that uses auxiliary belts to connect auxiliary equipment such as a water pump, a compressor, and a radiator fan necessary for operating an engine, an air conditioner, etc. Is an auxiliary drive belt system of a belt drive system that is connected and driven in an integrated manner, and a crank pulley 101 provided on a crankshaft of an engine that is a main machine, and auxiliary pulleys 201 to 201 provided on a shaft of each auxiliary machine The belt 301 is wound around the belt 205, and the driving force is transmitted to each auxiliary machine via the belt 301.

  In this embodiment, when transmitting the driving force generated by the engine to each auxiliary machine in the example shown in FIG. 1, the crank pulley 101 of the engine is referred to as a drive pulley, and the auxiliary pulleys 201 to 201 of each auxiliary machine are used. 205 is called a driven pulley. In addition, in an auxiliary machine drive system provided with a starter function generator (ISG: Integrated Start Generator) as an auxiliary machine, when an engine start or drive assist is performed by transmitting a drive force by the ISG, an ISG shaft The ISG pulley provided in the shaft is a driving pulley, and the crank pulley 101 is a driven pulley.

  FIG. 2 is a conceptual diagram showing the relationship between the transmission torque in the drive pulley and the tension on the tension side and the loose side. FIG. 3 is a diagram showing the relationship between transmission torque and tension in an accessory drive system in which a belt is wound around two pulleys. In the example shown in FIGS. 2 and 3, the relationship between the tension side tension T1 and the slack side tension T2 when the driving pulley 100 generates a driving force in the direction of the arrow is shown. FIG. 3 (a-1) shows an example in which the tensioner 400 is not provided on either the tension side or the loose side, and FIG. 3 (a-2) shows that the tensioner 400 is provided on either the tension side or the loose side. It shows the relationship between the transmission torque and tension when not. 3 (b-1) shows an example in which the tensioner 400 is provided on the tension side, and FIG. 3 (b-2) shows the relationship between the transmission torque and the tension when the tensioner 400 is provided on the tension side. Yes. 3 (c-1) shows an example in which a tensioner 400 is provided on the loose side, and FIG. 3 (c-2) shows the relationship between transmission torque and tension when the tensioner 400 is provided on the loose side. Yes. Moreover, the broken line described in FIG. 3 (a-2) thru | or FIG. 3 (c-2) shows the ideal characteristic of tension | tensile_strength side tension | tensile_strength T1, and it describes in FIG. 3 (a-2) thru | or FIG. The alternate long and short dash line indicates the ideal characteristic of the slack side tension T2.

  As shown in FIG. 2, when the driving pulley 100 rotates in the direction indicated by the arrow to generate a driving force, the transmission torque N transmitted by the belt is the radius r of the driving pulley 100, the tension on the tension side T1, the loose side. It represents with the following formula | equation using tension | tensile_strength T2.

  N = r × (T1-T2)

  As shown in the above equation, the transmission torque N is proportional to the tension difference T1-T2 between the tension side tension T1 and the loose side tension T2. That is, the driving force generated by the driving pulley 100 can be transmitted to the driven pulley by giving the tension difference T1-T2 necessary for transmitting torque without causing slip in the accessory driving system.

  As shown in FIG. 3 (a-1), even when the tensioner 400 is not provided on either the tension side or the loose side, the initial tension T0 applied to the belt is appropriately set as shown in FIG. 3 (a-2). Is set, the maximum transmission torque Nmax in the accessory drive system can be obtained. Here, when the slack side tension T2 becomes equal to or less than the minimum value T2min of the slack side tension T2 for obtaining the maximum transmission torque Nmax, slip of the belt 300 occurs in the maximum transmission torque Nmax or a transmission torque region below the maximum transmission torque Nmax. . Accordingly, it is necessary to set the initial tension T0 so that the slack side tension T2 does not fall below the minimum value T2min when the maximum transmission torque Nmax to be achieved in the accessory drive system is generated. In the example shown in FIG. 3, when the maximum transmission torque Nmax is generated, the maximum value of the tension side tension T1 when the loose side tension T2 becomes the minimum value T2min is T1max.

  As shown in FIG. 3 (b-1), when the tensioner 400 is provided on the tension side and the maximum transmission torque Nmax is achieved by keeping the tension side tension T1 constant, the tension is shown in FIG. 3 (b-2). Thus, it is necessary to set the tensioner 400 so that the initial tension T0 is equal to or greater than T1max. In this case, excessive tension that is not necessary in the transmission torque region below the maximum transmission torque Nmax is applied to the belt 300, and a large load is applied to the driving pulley 100 and the driven pulley 200, so that the transmission efficiency of the driving force is improved. descend.

  On the other hand, as shown in FIG. 3 (c-1), when the tensioner 400 is provided on the slack side and the slack side tension T2 is kept constant, the maximum transmission torque Nmax is to be achieved. As shown in -2), the tensioner 400 may be set so that the initial tension T0 is T2 min or more. However, even when the tensioner 400 is provided on the loose side (see FIG. 3 (c-1)), it is necessary to always apply a tension of T2 min or more to the loose side regardless of the magnitude of the transmission torque (FIG. 3 (c). -2)). In an internal combustion engine such as an automobile, the loss in a low torque region such as idling or high-speed running is made smaller, and the loose side tension T2 is brought closer to the ideal characteristic, that is, the loose side tension T2 proportional to the magnitude of the transmitted torque. It is expected that fuel efficiency will be further improved.

  FIG. 4 is a structural conceptual diagram of an accessory drive system to which the accessory drive belt tension adjusting device according to the embodiment is applied. In the accessory drive system shown in FIG. 4, a belt 3 that transmits a driving force is wound between a first pulley 1 and a second pulley 2. FIG. 4 shows an example of the structural concept in the initial state of the accessory drive system to which the accessory drive belt tension adjusting device according to the present embodiment is applied, that is, in the stopped state of the accessory drive system.

  In the accessory drive system shown in FIG. 4, the first pulley 1 is, for example, a crank pulley provided on the crankshaft of an engine that is an internal combustion engine of an automobile, and the second pulley 2 is provided on, for example, an ISG shaft. ISG pulley. That is, in the auxiliary drive system shown in FIG. 4, the drive side and the driven are driven in the case where the driving force by the engine is transmitted to the ISG for regeneration, and in the case where the driving force by the ISG is transmitted for engine start and drive assist. The side changes. That is, during regeneration, the crank pulley as the first pulley 1 serves as a drive pulley, the ISG pulley as the second pulley 2 serves as a driven pulley, and the ISG pulley as the second pulley 2 serves as the drive pulley during engine startup or drive assist. The crank pulley which is the pulley 1 is a driven pulley. In this way, in the auxiliary drive system in which the drive side and the driven side are switched, the tension side and the loose side are switched depending on which pulley is the drive pulley, so depending on which pulley is the drive pulley. Bidirectional transmission torque is generated. That is, in the auxiliary drive system in which the drive side and the driven side are switched, the belt 3 is driven bidirectionally from one to the other between the crank pulley as the first pulley 1 and the ISG pulley as the second pulley 2. Transmit power.

  As described above, in the accessory drive system, it is preferable to apply the slack side tension proportional to the magnitude of the transmission torque. The auxiliary machine drive belt tension adjusting device 10 according to the present embodiment can provide the belt 3 with a loose side tension T2 proportional to the transmission torque generated in both directions in an auxiliary machine drive system in which the drive side and the driven side are switched. It has a possible configuration. Hereinafter, the configuration of the accessory drive belt tension adjusting device 10 according to the present embodiment will be described. In the following description, it is assumed that the belt 3 advances in the direction indicated by the arrow shown in FIG.

  As shown in FIG. 4, the accessory drive belt tension adjusting device 10 according to this embodiment includes a first roller 11, a second roller 12, an arm 13, a base member 14, and a plurality of springs (first elasticity). Members) 15a1, 15b1, 15c1 and a plurality of springs (second elastic members) 15a2, 15b2, 15c2.

  The first roller 11 applies tension to the delivery section of the belt 3 from the second pulley 2 to the first pulley 1. The second roller 12 applies tension to the delivery section of the belt 3 from the first pulley 1 to the second pulley 2.

  The arm 13 supports the first roller 11 and the second roller 12 in a swingable manner with the rotational axis AX of the second pulley 2 as the pivot axis.

  The base member 14 is fixed in the circumferential direction with respect to the rotation axis AX of the second pulley 2.

  The plurality of springs (first elastic members) 15 a 1, 15 b 1, 15 c 1 are provided between different predetermined positions a 1, b 1, c 1 on the base member 14 and the rotation axis of the first roller 11, respectively. An urging force is applied in a direction perpendicular to the rotation axis BX of the roller 11.

  The plurality of springs (second elastic members) 15 a 2, 15 b 2, and 15 c 2 are provided between different predetermined positions a 2, b 2, and c 2 on the base member 14 and the rotation axis of the second roller 12, respectively. An urging force is applied in a direction perpendicular to the rotation axis CX of the roller 12.

  In the configuration described above, the attachment positions a1, b1, c1 of the springs (first elastic members) 15a1, 15b1, 15c1 to the base member 14, and the base members 14 of the springs (second elastic members) 15a2, 15b2, 15c2. The urging force applied to the first roller 11 and the second roller 12 and the direction thereof can be set by the mounting positions a2, b2, c2 and the spring constants of the springs 15a1, 15b1, 15c1, 15a2, 15b2, 15c2. As a result, in the accessory drive system in which the drive side and the driven side are interchanged as shown in FIG. 4, it is possible to apply a loose side tension T2 proportional to the transmission torque generated in both directions to the belt 3.

  The present invention is not limited by the materials and shapes of the springs (first elastic members) 15a1, 15b1, 15c1 and the springs (second elastic members) 15a2, 15b2, 15c2, and may be, for example, leaf springs or coil springs. It may be a solid member such as elastic rubber.

  Hereinafter, with reference to FIG. 4 thru | or FIG. 9, the operation example of the auxiliary machine drive belt tension adjusting apparatus 10 which concerns on this embodiment is demonstrated. FIG. 5 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the embodiment when the first pulley generates driving force. FIG. 6 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the embodiment when the second pulley generates the driving force. FIG. 7 is a structural conceptual diagram of an accessory drive system to which an accessory drive belt tension adjusting device according to a comparative example is applied. FIG. 8 is a diagram illustrating a reference example in which the relationship between the spring force applied to the belt in the direction perpendicular to the belt by each spring that applies a biasing force to the central axis of the first pulley and the swing angle of the first pulley is simulated. FIG. 9 is a diagram showing a reference example in which the relationship between the spring force applied in the direction perpendicular to the traveling direction of the belt and the deflection angle of the first pulley by each spring applying a biasing force to the central axis of the first pulley is simulated. It is. In FIG. 8, simulation results in the comparative example shown in FIG. 7 are also shown.

  In the present embodiment, each spring (first elastic member) 15a1, 15b1, 15c1 is applied to the first roller 11 so that an appropriate initial tension T0 is applied to the belt 3 in the initial state of the accessory drive system shown in FIG. The urging force to be applied (the pushing direction or the pulling direction), the urging force that each spring (second elastic member) 15a2, 15b2, 15c2 applies to the second roller 12, and the spring constant of each spring (first elastic member) 15a1, 15b1, 15c1 The spring constants of the springs (second elastic members) 15a2, 15b2, and 15c2 are set. Further, the biasing force and the spring constant that the spring (first elastic member) 15a1 applies to the first roller 11 are equivalent to the biasing force and the spring constant that the spring (second elastic member) 15a2 applies to the second roller 12. The biasing force and spring constant that the spring (first elastic member) 15b1 applies to the first roller 11 are equivalent to the biasing force and spring constant that the spring (second elastic member) 15b2 applies to the second roller 12. The biasing force and the spring constant that the spring (first elastic member) 15c1 applies to the first roller 11 are equivalent to the biasing force and the spring constant that the spring (second elastic member) 15c2 applies to the second roller 12. Also, the spring constant ka of the spring (first elastic member) 15a1 and the spring (second elastic member) 15a2, the spring constant kb of the spring (first elastic member) 15b1 and the spring (second elastic member) 15b2, and the spring ( The spring constant kc of the first elastic member) 15c1 and the spring (second elastic member) 15c2 is set to have a relationship of ka <kb <kc.

  In the example shown in FIGS. 8 and 9, the swing angle θ1 (or θ2) of the arm 13 is 42.84 [degrees] in the initial state of the accessory drive system, and in the region below 42.84 [degrees], the first The side to which the roller 11 (or the second roller 12) applies tension is the tension side, and in the region of 42.84 [degrees] or more, the side to which the first roller 11 (or the second roller 12) applies tension is the loose side.

  In the example shown in FIG. 8, the spring load applied in the vertical direction of the belt 3 by the spring (first elastic member) 15a1 is Fva1, and the spring load applied in the vertical direction of the belt 3 by the spring (first elastic member) 15b1 is Fvb1. Fvc1 is a spring load applied in the vertical direction of the belt 3 by the spring (first elastic member) 15c1, and a total spring load of the spring load applied in the vertical direction of the belt 3 by each spring (first elastic member) 15a1, 15b1, 15c1. FvA1, the spring load applied in the vertical direction of the belt 3 by the spring (second elastic member) 15a2 is Fva2, the spring load applied in the vertical direction of the belt 3 by the spring (second elastic member) 15b2 is Fvb2, and the spring (second elastic member). Member) 15c2, the spring load applied to the belt 3 in the vertical direction is Fvc2, and each spring (second elastic member) 15a. The total spring load of the spring load applied in the vertical direction of the belt 3 and FvA2 by 15B2,15c2, in the comparative example shown in FIG. 7, and a FvB a spring load applied in the vertical direction of the belt 3 by the tension arm 13a.

  In the example shown in FIG. 9, the spring load applied in the traveling direction of the belt 3 by the spring (first elastic member) 15a1 is Fha1, and the spring load applied in the traveling direction of the belt 3 by the spring (first elastic member) 15b1 is Fhb1. Fhc1 represents the spring load applied in the moving direction of the belt 3 by the spring (first elastic member) 15c1, and the total spring load applied in the moving direction of the belt 3 by each spring (first elastic member) 15a1, 15b1, 15c1. FhA1, the spring load applied in the traveling direction of the belt 3 by the spring (second elastic member) 15a2 is Fha2, the spring load applied in the traveling direction of the belt 3 by the spring (second elastic member) 15b2 is Fhb2, and the spring (second elastic member). Member) 15c2, the spring load applied in the traveling direction of the belt 3 is Fhc2, and each spring (second elastic member) 15a. Has a FhA2 the total spring load of the spring load applied to the traveling direction of the belt 3 by 15B2,15c2.

  In the auxiliary machine driving belt tension adjusting device 10 according to the present embodiment, when the first pulley 1 is a driving pulley and the second pulley 2 is a driven pulley, as shown in FIG. When the belt 3 is pushed, the deflection angle θ1 of the arm 13 is reduced (or θ2 is increased), and the second roller 12 pushes the belt 3 along with this, thereby applying tension to the loose side by the second roller 12. It is done. When the first pulley 1 is a driven pulley and the second pulley 2 is a drive pulley, the second roller 12 is pushed by the belt 3 and the arm 13 has a deflection angle θ2 as shown in FIG. When the first roller 11 pushes the belt 3 along with the decrease (or θ1 increases), a tension is applied to the loose side by the first roller 11.

  In the comparative example shown in FIG. 7, each spring (first elastic member) 15a1, 15b1, 15c1 and each spring (second elastic member) 15a2, 15b2, 15c2 of this embodiment is not provided, but by the tension arm 13a. In this configuration, the tension at which the transmission torque becomes maximum is given as the initial tension T0. In such a configuration, the maximum spring load is always applied to the belt 3 regardless of the deflection angles θ1 and θ2 of the tension arm 13a, so that the region where the transmission torque is small (here, the deflection angle θ1 (θ2) = 42.84). Even in the vicinity of [degree], excessive tension that is not necessary in that region is applied to the belt 3, a large load is applied to the first pulley 1 and the second pulley 2, and the transmission efficiency of the driving force is reduced. It becomes.

  On the other hand, in the accessory drive belt tension adjusting device 10 according to the present embodiment, the overall force given from the first roller 11 and the second roller 12 to the belt 3 by the springs 15a1, 15b1, 15c1, 15a2, 15b2, and 15c2. Spring force and the total reaction force acting on the springs 15a1, 15b1, 15c1, 15a2, 15b2, and 15c2 from the belt 3 via the first roller 11 and the second roller 12 are always balanced. . That is, the spring load of all the springs 15a1, 15b1, 15c1, 15a2, 15b2, and 15c2 interacts with each other on the tension side roller and the loose side roller so that the belt 3 The springs 15a1, 15b1, 15c1, 15a2, 15b2, and 15c2 are in balance with the total reaction force acting on them. In the present embodiment, by setting the mounting positions and spring constants of the plurality of springs 15a1, 15b1, 15c1, 15a2, 15b2, and 15c2 to the base member 14 individually, the tension proportional to the transmission torque is reduced and the side tension is reduced. It becomes possible to give to the belt 3.

  That is, in the auxiliary machine drive belt tension adjusting apparatus 10 according to the present embodiment, the attachment positions a1, b1, c1 of the springs (first elastic members) 15a1, 15b1, 15c1 to the base member 14 and the springs (second elastic members). Members) 15a2, 15b2, and 15c2 are attached to the base member 14 by the positions a2, b2, and c2, and the spring constants of these springs 15a1, 15b1, 15c1, 15a2, 15b2, and 15c2, and the like. Since the urging force applied to the belt 3 via the belt 12 and its direction can be set, in the auxiliary drive system in which the drive side and the driven side are interchanged as shown in FIG. 4, it is proportional to the transmission torque generated in both directions. The slack side tension T2 thus obtained can be applied to the belt 3.

  Furthermore, in the auxiliary machine drive belt tension adjusting device 10 according to the present embodiment, the spring load in the opposite direction (−) to the traveling direction of the belt 3 is increased on the tension side. As a result, the force by which the first roller 11 (or the second roller 12) on the loose side pushes the belt 3 is difficult to escape.

(Modification)
FIG. 10 is a structural conceptual diagram of an accessory drive system to which an accessory drive belt tension adjusting device according to a modification of the embodiment is applied. FIG. 11 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the modification of the embodiment when the first pulley generates the driving force. FIG. 12 is a diagram illustrating an operation example of the accessory driving belt tension adjusting device according to the modification of the embodiment when the second pulley generates the driving force.

  10 to 12, instead of the arm 13 in the configuration shown in FIGS. 4 to 6, a tension arm 13a formed of an elastic member that applies a biasing force in the swinging direction of the first roller 11 and the second roller 12 is used. An applied configuration example is shown.

  Also in the configuration of the accessory drive belt tension adjusting device 10a shown in FIG. 10, as in the configuration shown in FIG. 4, when the first pulley 1 is a drive pulley and the second pulley 2 is a driven pulley, As shown in FIG. 11, the first roller 11 is pushed by the belt 3, and the swing angle θ1 of the arm 13 (here, the tension arm 13a) is reduced (or θ2 is increased). When the belt 12 presses the belt 3, tension is applied to the loose side by the second roller 12. When the first pulley 1 is a driven pulley and the second pulley 2 is a drive pulley, the second roller 12 is pushed by the belt 3 and the arm 13 (here, tension) as shown in FIG. The deflection angle θ2 of the arm 13a) decreases (or θ1 increases), and the first roller 11 pushes the belt 3 along with this, whereby tension is applied to the loose side by the first roller 11.

  As described above, the comparative example described with reference to FIG. 7 includes the springs (first elastic members) 15a1, 15b1, and 15c1 and the springs (second elastic members) 15a2, 15b2, and 15c2 of this embodiment. However, the tension at which the transmission torque is maximized by the tension arm 13a is applied as the initial tension T0. However, in the configuration of the accessory drive belt tension adjusting device 10a shown in FIG. Member) 15a1, 15b1, 15c1 and each spring (second elastic member) 15a2, 15b2, 15c2, the tension arm 13a gives the minimum required initial tension T0 at the beginning of transmission torque being applied to the belt 3. You just have to keep it.

  As described above, the accessory driving belt tension adjusting devices 10 and 10a according to the embodiment of the belt 3 that transmits the driving force bidirectionally from one to the other between the first pulley 1 and the second pulley 2 are provided. A first roller 11 that applies tension to a delivery section from the second pulley 2 to the first pulley 1; a second roller 12 that applies tension to a delivery section from the first pulley 1 to the second pulley 2 of the belt 3; 2 With the rotation axis AX of the pulley 2 as the pivot axis, the arm 13 that supports the first roller 11 and the second roller 12 in a swingable manner, and the direction perpendicular to the rotation axis BX of the first roller 11 A plurality of springs (first elastic members) 15a1, 15b1, and 15c1 that apply urging force, and a plurality of springs (second elastic members) 15a2 that apply urging force in a direction perpendicular to the rotation axis CX of the second roller 12. 15b2, 15c2, Eteiru.

  In this configuration, the biasing force that each spring (first elastic member) 15a1, 15b1, 15c1 applies to the first roller 11 and the second roller 12 by the spring constant of each spring (first elastic member) 15a1, 15b1, 15c1. The springs (second elastic members) 15a2, 15b2, and 15c2 are connected to the first roller 11 and the second roller 12 according to the spring constants of the springs (second elastic members) 15a2, 15b2, and 15c2. The biasing force to be applied can be set. As a result, the slack side tension T2 proportional to the transmission torque generated bidirectionally from one to the other between the first pulley 1 and the second pulley 2 can be applied to the belt 3, and the driving side and the driven side are It is possible to reduce the loss of the auxiliary drive system to be replaced.

  Further, a base member 14 fixed in the circumferential direction with respect to the rotational axis AX of the second pulley 2 is provided, and the springs (first elastic members) 15a1, 15b1, and 15c1 are respectively set at different predetermined positions a1 of the base member 14. , B1, c1 and the rotation axis of the first roller 11, and each spring (first elastic member) 15a1, 15b1, 15c1 is attached to each spring (first spring) by a predetermined position a1, b1, c1. The elastic members 15a1, 15b1, 15c1 set the urging force and direction applied to the first roller 11 and the second roller 12, and the springs (second elastic members) 15a2, 15b2, 15c2 are respectively different from the base member 14. Each predetermined position that is provided between the predetermined positions a2, b2, c2 and the rotation axis of the second roller 12 and attaches springs (second elastic members) 15a2, 15b2, 15c2. The first and second pulleys 1 and 2 are set by a2, b2, and c2 to set the urging force and the direction that each spring (second elastic member) 15a2, 15b2, and 15c2 applies to the first roller 11 and the second roller 12. It is also possible to apply a slack side tension T2 proportional to the transmission torque generated bi-directionally from one to the other.

  Further, by using the tension arm 13a formed of an elastic member that applies a biasing force in the swinging direction of the first roller 11 and the second roller 12 in place of the arm 13, the transmission torque starts to be applied to the tension arm 13a. What is necessary is just to give the minimum necessary initial tension T0 in the initial stage.

  In the above-described embodiment, the configuration including three first elastic members and three second elastic members is shown. However, the number of the first elastic members and the second elastic members is not limited to this. The structure which has the 1st elastic member and the 2nd elastic member of this number or four or more may be sufficient, and the number of the 1st elastic members and the number of the 2nd elastic members may not be the same. Moreover, although the shape of the base member is circular, the shape of the base member is not limited to this, and may be any shape that can secure the mounting positions of the first elastic members and the second elastic members. Moreover, although the attachment position of each 1st elastic member and each 2nd elastic member was provided on the same periphery, the attachment position of each 1st elastic member and each 2nd elastic member is not restricted to this.

  As described above, by using the accessory drive belt tension adjusting devices 10 and 10a according to the present embodiment, the transmission torque is proportional to the transmission torque generated bidirectionally from one to the other between the first pulley and the second pulley. Since the slack side tension can be applied to the belt, the accessory drive belt tension adjusting devices 10 and 10a according to this embodiment are suitable for reducing the loss of the accessory drive system in which the drive side and the driven side are switched. Yes.

DESCRIPTION OF SYMBOLS 1 1st pulley 2 2nd pulley 3 Belt 10, 10a Auxiliary machine drive belt tension adjusting device 11 1st roller 12 2nd roller 13 Arm 13a Tension arm (elastic member)
14 Base member 15a1, 15b1, 15c1 Spring (first elastic member)
15a2, 15b2, 15c2 Spring (second elastic member)
DESCRIPTION OF SYMBOLS 100 Drive pulley 101 Crank pulley 200 Driven pulley 201-205 Auxiliary machine pulley 301 Belt 400 Tensioner AX Rotation shaft center (2nd pulley)
BX Rotating shaft (first roller)
CX Rotating shaft (second roller)
T0 Initial tension T1 Tension side tension T2 Loose side tension

Claims (2)

A first roller that applies tension to a delivery section from the second pulley to the first pulley of a belt that transmits a driving force bidirectionally from one to the other between the first pulley and the second pulley;
A second roller that applies tension to a delivery section of the belt from the first pulley to the second pulley;
An arm that pivotally supports the first roller and the second roller with the rotation axis of the second pulley as a pivot axis;
A plurality of first elastic members for applying a biasing force in a direction perpendicular to the rotation axis of the first roller;
A plurality of second elastic members for applying a biasing force in a direction perpendicular to the rotation axis of the second roller;
With
Auxiliary drive belt tension adjuster. A base member fixed in the circumferential direction with respect to the rotational axis of the second pulley;
The plurality of first elastic members are respectively provided between different predetermined positions of the base member and the rotation axis of the first roller,
The plurality of second elastic members are respectively provided between different predetermined positions of the base member and the rotation axis of the second roller.
The auxiliary machine drive belt tension adjusting device according to claim 1.

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