JP2011226439A - Belt drive device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt drive device for an internal combustion engine having a generator motor and capable of appropriately setting belt tension both during power generation and at start of the engine.SOLUTION: In the belt drive device for the internal combustion engine, an automatic tension control device is provided in the middle of a belt leading from the generator motor toward a crank output shaft along the circulating direction of the belt. The automatic tension control device has predetermined spring force and includes a fixation function for stopping a spring function when reaction force exceeding a predetermined level is received from the belt. Thus, the belt drive device for the internal combustion engine can appropriately hold the belt tension both at start of the engine and during power generation.

Description

  The present invention relates to a belt drive device for an internal combustion engine in which a crankshaft of an internal combustion engine and various auxiliary machines are connected by a belt and the auxiliary machines are driven by the belt.

  In a belt drive device for an internal combustion engine, a generator, a water pump, a compressor of an air conditioner, and the like are wound around the belt as auxiliary devices. In recent years, generator motors are known. This is because when the engine is operating, power is generated by the driving force obtained from the crankshaft by power transmission by the belt, while when the engine is stopped, it is driven by the starting power supplied from the outside, and the belt This is a generator having a function of starting the engine by rotating the crankshaft by the power transmission by.

  Since the belt drive device cannot transmit power by the belt when the frictional force between the belt and the pulley disappears, a predetermined tension is applied to the belt in advance. Further, when the driving force is transmitted through the belt, the belt driving device increases the tension on the side where the belt is pulled and the tension on the side where the belt is sent out, with the pulley serving as the driving source as a boundary. The belt driving device applies a large tension in advance so that the minimum necessary tension remains on the belt slack side, and even if the belt loosens due to aging, the minimum necessary tension remains. It is attached to the belt.

  However, if a large tension is applied to the belt in advance, an excessive load is always applied to the belt and pulley bearings. Therefore, an automatic tension adjuster (auto tensioner) is provided in the loose side area where the belt of the belt drive device is loosened. When the tension is reduced in the belt in the loose side area, the tension is added and the minimum necessary tension is generated in the belt. It was like that.

Japanese Patent No. 3129268

  However, in the case of an internal combustion engine equipped with a generator motor, a loose side region is used when the internal combustion engine is operated to transmit driving force to the generator motor and when the crank motor is driven to rotate by driving the generator motor. Appear in opposite positions. When the vehicle is traveling normally, that is, when the engine is operating and the generator motor is being driven, the belt is loosened when the generator motor is operated and the engine is started.

  If an automatic tension adjuster (auto tensioner) is installed in the area on the loose side during normal driving, excessive tension will be generated in the automatic tension adjuster when the engine is started, and the automatic tension adjuster will not be able to handle it. Sometimes.

  Therefore, it is selected that the automatic tension adjuster is provided on the side where the belt is loosened when the engine is started. However, the side where the looseness occurs when starting the engine is the side where the belt is tensioned during normal driving, so the automatic tension adjuster provided on the loosening side when starting the engine has a strong force that can handle the large tension generated during power generation. It is necessary to have a strong spring force. On the other hand, if a strong tension is preliminarily applied to the belt by the automatic tension adjuster, a large load is applied to the rotating shafts of the auxiliary machinery, which may cause a problem in durability.

  According to the present invention, in an internal combustion engine equipped with a generator motor, a predetermined amount of tension is always applied to the belt even when power is generated by the generator motor and when the engine is started. An object of the present invention is to provide a belt drive device that can cope with the above.

  In order to solve the above-described problems, the present invention has a belt drive device for an internal combustion engine configured as follows. That is, the disclosed belt drive device for an internal combustion engine winds the pulley provided on the crank output shaft of the internal combustion engine and the pulley provided on the drive shaft of the auxiliary machinery with a belt, and the auxiliary output from the crank output shaft. A belt drive device for an internal combustion engine for transmitting power to machinery, wherein the auxiliary machinery is a generator motor and a belt slack side where the belt loosens when the internal combustion engine is started by the generator motor, An at least one auxiliary device provided on the way from the generator motor to the crank output shaft along the circumferential direction of the belt, and automatically applying tension to the belt on the way from the generator motor to the auxiliary device. A tension adjuster, and when the automatic tension adjuster receives a pressing force exceeding the spring force together with a predetermined spring force for applying tension to the belt, the spring operation is stopped. Characterized by being configured to include a stop mechanism.

  As a result, the loosening at the start of the engine is eliminated by the action of the auto tensioner, and the adjustment mechanism of the automatic tension adjuster is stopped when a pressing force exceeding a predetermined level is applied, reducing the axial load during normal driving. It becomes possible.

  Further, the disclosed internal combustion engine belt drive apparatus is the internal combustion engine belt drive apparatus, wherein the automatic tension adjuster includes an outer frame body, a movable body movably provided in the outer frame body, and the movement. A pulley provided on the body and a spring member for advancing the moving body outward, and the pulley is advanced outward by the spring member to apply tension to the belt, and the moving body has a predetermined amount The outer frame body is provided with an abutting portion that abuts the moving body when retreating and stops the retreating operation of the moving body.

  Further, the disclosed internal combustion engine belt drive device is the internal combustion engine belt drive device, wherein the automatic tension adjuster generates power from the belt when generating power with the generator motor by a pulley provided on the crank output shaft. It is characterized by receiving a pressing force exceeding the spring force.

  As a result, the adjustment mechanism of the automatic tension adjuster is fixed during normal travel, so there is no need to have a strong spring force that can handle the large tension when the belt is tensioned, and the axial load of the auxiliary devices Can be reduced.

  Further, in the disclosed belt drive device for an internal combustion engine, in the belt drive device for an internal combustion engine, the inter-pulley belt distance between the generator motor and the accessory is the longest inter-pulley belt distance in the belt circumferential direction. It is characterized by that.

  As a result, the looseness is likely to appear remarkably at the place where the distance between the shaft centers is long, but the looseness can be effectively suppressed by arranging the automatic tension adjuster at the portion.

The belt drive device for an internal combustion engine according to the present invention has the following effects.
When the engine is started, a predetermined tension is generated on the belt by the automatic tension adjuster, and the idling of the belt is appropriately prevented. On the other hand, when a pressing force exceeding the spring force is received, the automatic tension adjuster is in a fixed state, so that a high belt tension can be reliably maintained, and even on the loose side, the tension can be maintained so as not to become a predetermined value or less. As a result, the belt tension is appropriately maintained and the power transmission by the belt driving device is reliably performed in both cases of normal running and engine start.

It is a block diagram which shows one Embodiment of the belt drive device concerning this invention. It is a block diagram which shows one Embodiment of the belt drive device concerning this invention. It is sectional drawing which shows one Embodiment of an automatic tension adjuster.

  An embodiment of a belt driving device according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a belt drive device 10 for an internal combustion engine. The belt driving device 10 includes a first pulley 14 attached to a crank output shaft 12 of an internal combustion engine, a second pulley 18 attached to a generator motor 16, and a third pulley attached to a driving shaft 20 of a cooling water pump. 22, a fourth pulley 26 attached to a drive shaft 24 of the compressor of the air conditioner, and a belt 30.

  The crank output shaft 12 is an output shaft of the internal combustion engine, and outputs power generated by the internal combustion engine. The internal combustion engine is a gasoline engine or a diesel engine. Further, the crank output shaft 12 can start the internal combustion engine when the starting torque is inputted.

  The cooling water pump is a pump for circulating the cooling water inside the internal combustion engine. When the drive shaft 20 is rotated, the pump operates. The compressor of the air conditioner is a compressor that compresses the refrigerant of the air conditioner. When the drive shaft 24 is rotated, the compressor operates. These are rotated as power by an internal combustion engine as an auxiliary machine. The auxiliary machine is not limited to this.

  The generator motor 16 is basically a generator, and generates electric power when it is rotationally driven by power from an internal combustion engine. Furthermore, the generator motor 16 can drive the rotation shaft by electric power supplied from the outside. When the rotating shaft of the generator motor 16 is rotated by external power in this way, the first pulley 14 is rotated by the second pulley 18, the crank output shaft 12 is rotated, and the internal combustion engine can be started.

  The belt 30 is annular and is wound around the first pulley 14 to the fourth pulley 26. An automatic tension adjuster 32 is provided between the second pulley 18 and the third pulley 22.

  An automatic tension adjuster 32 is shown in FIG. As shown in FIG. 3, the automatic tension adjuster 32 includes an outer frame body 34, a moving body 36, a spring member 38, a pulley 40 (see FIG. 1), and the like. As described above, the automatic tension adjuster 32 is provided between the second pulley 18 and the third pulley 22, that is, between the generator motor 16 and the compressor. That is, the automatic tension adjuster 32 is provided at a position where the belt 30 is on the tight side in a state where the generator motor 16 is rotationally driven by the rotational driving force output from the crank output shaft 12 to generate power.

  The outer frame body 34 is cylindrical, and a moving body 36 is accommodated therein so as to be movable in the axial direction of the outer frame body 34. The pulley 40 is attached to the moving body 36 and moves along the axial direction integrally with the moving body 36. The spring member 38 is a compression spring, and urges the moving body 36 outward, that is, in a direction of pushing out the pulley 40.

  The spring member 38 has a predetermined spring constant. When the engine is started, that is, when the belt 30 facing the automatic tension adjuster 32 is loosened, the spring member 38 is pressed and a predetermined tension is applied to the loose side of the belt 30. Is set to occur.

  Further, the automatic tension adjuster 32 includes a contact portion 44 that contacts the moving body 36 in the outer frame body 34. The contact portion 44 is provided so that the moving body 36 comes into contact when the tension of the belt 30 exceeds a predetermined value and the moving body 36 is moved backward by a predetermined amount. When the moving body 36 comes into contact with the contact portion 44, the spring function of the spring member 38 disappears, and the moving body 36 stops moving backward. As described above, the automatic tension adjuster 32 has a fixing function for fixing the movement of the spring member 38 when the tension of the belt 30 reaches a predetermined value.

Next, the operation of the belt driving device 10 will be described.
It is assumed that the engine is started by the generator motor 16 with the engine stopped. The starting power is supplied to the generator motor 16 to drive the generator motor 16. Then, the second pulley 18 of the generator motor 16 rotates as indicated by the arrow in FIG. The rotational force of the second pulley 18 is transmitted to the first pulley 14 via the third pulley 22 and rotates the first pulley 14. As a result, the crank output shaft 12 of the engine rotates and the engine is started. On the other hand, the belt 30 fed from the second pulley 18 returns to the first pulley 14 of the crank output shaft 12 through the pulley 40 of the automatic tension adjuster 32 and the fourth pulley 26.

  Thus, the portion of the belt 30 that extends from the second pulley 18 through the third pulley 22 to the first pulley 14 becomes a so-called tension side, and high tension is generated. The region of the belt 30 that extends from the second pulley 18 through the fourth pulley 26 to the first pulley 14 is a so-called loose side, and weak tension is generated. On the loose side, the spring force of the spring member 38 is applied to the belt 30 through the pulley 40 from the automatic tension adjuster 32, and a predetermined tension is applied to the belt 30 and is absorbed even if the belt 30 is stretched. .

  On the other hand, when the engine is started and the vehicle is in a normal running state, the first pulley 14 of the crank output shaft 12 rotates with a driving force as shown by an arrow in FIG. Then, the driving force of the crank output shaft 12 is transmitted from the first pulley 14 to the second pulley 18 via the fourth pulley 26 and further rotates the third pulley 22. As a result, the pump and the compressor operate, and the generator motor 16 operates to generate power.

  Then, the portion of the belt 30 that extends from the first pulley 14 through the fourth pulley 26 to the second pulley 18 becomes a so-called tension side region, and high tension is generated. Since the belt 30 on the tension side is in contact with the automatic tension adjuster 32 and the belt 30 has a high tension, a large compressive force is applied to the spring member 38 from the belt 30. However, a contact portion 44 is formed on the outer frame body 34 of the automatic tension adjuster 32, and when the moving body 36 is retracted by the pressing force from the belt 30, the moving body 36 contacts the contact portion 44. Thus, the backward movement of the moving body 36 is stopped.

  Therefore, even if the vehicle shifts to normal running and power is generated by the generator motor 16 by the power from the crank output shaft 12, the automatic tension adjuster 32 does not move any further when the pulley 40 moves back to a predetermined position. Therefore, the tension of the belt 30 is maintained in a predetermined state by the automatic tension adjuster 32. The portion of the belt 30 that extends from the first pulley 14 through the third pulley 22 to the second pulley 18 is a so-called loose side, and the generated tension is weak, but the automatic tension adjuster 32 causes the tension to be below a predetermined level. There is no.

  As described above, according to the automatic tension adjuster 32, the required tension is applied to the belt 30 both when the generator motor 16 generates power and when the engine is started. Further, the tension generated on the tension belt 30 when the generator motor 16 is generating electric power can be sufficiently held, and the automatic tension adjuster 32 is not damaged. Further, it is not necessary to apply excessive tension to the belt 30 in advance, and durability of the belt 30 and the bearings of auxiliary machinery can be improved.

  It can be used for a belt drive device of an internal combustion engine provided with a generator motor.

DESCRIPTION OF SYMBOLS 10 ... Belt drive device 12 ... Crank output shaft 14 ... 1st pulley 16 ... Generator motor 18 ... 2nd pulley 20 ... Drive shaft 22 ... 3rd pulley 24 ... Drive shaft 26 ... 4th pulley 30 ... Belt 32 ... Automatic tension adjustment 34 ... Outer frame 36 ... Moving body 38 ... Spring member 40 ... Pulley 44 ... Contact part

Claims (4)

A belt drive for an internal combustion engine in which a pulley provided on a crank output shaft of an internal combustion engine and a pulley provided on a drive shaft of auxiliary machinery are wound by a belt and power is transmitted from the crank output shaft to the auxiliary machinery. Device,
The auxiliary machines are a generator motor and a belt slack side where the belt loosens when the internal combustion engine is started by the generator motor, and the crank output shaft extends from the generator motor along the circumferential direction of the belt. At least one auxiliary machine on the way to
An automatic tension adjuster that applies tension to the belt on the way from the generator motor to the auxiliary machine;
The automatic tension adjuster includes a predetermined spring force that applies tension to the belt and a stop mechanism that stops a spring operation when a pressing force exceeding the spring force is received. A belt drive device for an internal combustion engine. The automatic tension adjuster includes an outer frame body, a movable body provided movably in the outer frame body, a pulley provided in the movable body, and a spring member that advances the movable body outward. ,
An abutting portion for advancing the pulley outward by the spring member to apply tension to the belt and abutting the moving body when the moving body is retracted by a predetermined amount and stopping the retracting operation of the moving body The belt drive device for an internal combustion engine according to claim 1, wherein the belt is provided on the outer frame body.   The automatic tension adjuster receives a pressing force exceeding the spring force from the belt when generating power with the generator motor by a pulley provided on the crank output shaft. Belt drive device for internal combustion engine.   4. The internal combustion engine according to claim 1, wherein the inter-pulley belt distance between the generator motor and the auxiliary machine is the longest inter-pulley belt distance in the circumferential direction of the belt. 5. Belt drive device.

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