JP5759344B2 - Auxiliary drive device for internal combustion engine - Google Patents

Description

  The present invention relates to an auxiliary machine drive device for an internal combustion engine in which three auxiliary machines are driven by a crank pulley.

  Generally, in an internal combustion engine having a plurality of cylinders, an auxiliary machine drive device using a transmission belt is arranged at one end of a crankshaft along the cylinder row direction. This auxiliary machine drive device is configured by winding a transmission belt around a crank pulley fixed to one end of a crankshaft and an auxiliary machine pulley for driving each auxiliary machine, and outputs the output of the internal combustion engine via the transmission belt. Is transmitted to the auxiliary pulley to drive each auxiliary machine.

  In recent years, in order to reduce the size of an engine, a form in which a plurality of auxiliary machines are driven by a single transmission belt has been adopted. In this case, a V-belt having a larger transmission capability than the flat belt is often used for the transmission belt. Further, in order to ensure a frictional force even when the transmission belt is stretched or worn, an auto tensioner that keeps the tension of the transmission belt constant is generally used. The auto tensioner normally applies tension to the transmission belt by urging a tension pulley disposed on the loose side of the transmission belt with respect to the crank pulley toward the side in contact with the transmission belt.

  In such an auxiliary machine drive device, it is desired that the auxiliary machine is arranged as compactly as possible including the auxiliary machine. On the other hand, in order to ensure the frictional force with the transmission belt, it is necessary to increase the diameter of each auxiliary pulley to some extent and to secure the winding angle of the transmission belt around each auxiliary pulley. Both a compact arrangement of pulleys and securing of power transmission for each auxiliary pulley are required.

  For example, in the auxiliary machine driving device disclosed in Patent Document 1, in an automobile engine that is largely inclined rearward, a plurality of auxiliary machines are collectively arranged on one surface (front surface) side along the cylinder row direction in the internal combustion engine. , In order from the crank pulley to the tension side, the transmission belt, the compressor pulley for the air conditioner located in front of the crank pulley, the idler pulley, the alternator pulley located above the crank pulley, the water pump pulley located below the alternator pulley, It is wound around a tensioner pulley located in front of the water pump pulley and the crank pulley, only the tensioner pulley is brought into rolling contact with the outer surface of the transmission belt, and the other auxiliary pulleys are brought into rolling contact with the inner surface of the transmission belt.

Japanese Patent No. 452008

  By the way, in the above-mentioned accessory driving device, a load in the direction in which the transmission belt is wound (hereinafter referred to as a belt load) is applied to each pulley. The belt load is a resultant force of the tension force on the tension side and the tension force on the slack side of the transmission belt, and increases as the winding angle with respect to the pulley increases in the range where the winding angle is 180 degrees or less. Since the belt load acts in a direction orthogonal to the rotation axis of the pulley, as in Patent Document 1, when the direction of the belt load with respect to the crank pulley is close to the cylinder axis direction (piston sliding direction), the internal combustion engine Hitting noise may occur during driving. Moreover, in the auxiliary machine drive apparatus of patent document 1, since the distance of a compressor pulley and an alternator pulley becomes large, it becomes necessary to provide an idler pulley between both, and the enlargement of the apparatus is caused.

  The present invention has been devised to solve the problems included in such a conventional technique, and the direction of the belt load applied to the crank pulley is made different from the cylinder axial direction to suppress the generation of hitting sound, It is an object of the present invention to provide an accessory drive device that can be made compact with a minimum necessary configuration while ensuring power transmission.

  The present invention drives a crank pulley (10) provided at one end of a crankshaft (7) and a first auxiliary machine (21) arranged in a direction substantially perpendicular to the cylinder axis with respect to the crank pulley. 1 auxiliary machine pulley (11), 2nd auxiliary machine pulley (12) which drives the 2nd auxiliary machine (22) arrange | positioned in the cylinder axial direction rather than the said 1st auxiliary machine pulley, and cylinder axial direction A third auxiliary pulley (13) for driving a third auxiliary machine (23) arranged between the first auxiliary pulley and the second auxiliary pulley, and the second auxiliary machine in the cylinder axial direction. A tension pulley (14) disposed between the pulley and the third auxiliary pulley and urged by an auto tensioner (17); the first auxiliary pulley; 2 Auxiliary Pooh The tension pulley and the third auxiliary pulley are wound around the inner surface (15i) of the crank pulley, the first auxiliary pulley, the second auxiliary pulley and the tension pulley. The accessory drive device (1) includes an endless transmission belt (15) that abuts the outer surface (15o) of the third accessory pulley.

  In the accessory drive apparatus according to the present invention, the center (13x) of the third accessory pulley is the center (10x, 11x, 12x) of the crank pulley, the first accessory pulley, and the second accessory pulley. A straight line defined by the transmission belt between the crank pulley and the first auxiliary pulley is defined as a first imaginary line (31), of the crank pulley, A tangent line parallel to the first imaginary line at a portion on the outer periphery opposite to the first imaginary line is defined as a second imaginary line (32), and the first imaginary line on the outer periphery of the third auxiliary pulley. Is the first virtual point (35), the first virtual point is located between the first virtual line and the second virtual line, and the first auxiliary pulley and the first virtual point (35) 2 A straight line defined by the transmission belt between the auxiliary pulley A tangent line parallel to the third imaginary line at a portion on the outer peripheral edge of the tension pulley on the side close to the crank pulley is defined as a fourth imaginary line (34). A configuration in which the second virtual point is located between the third virtual line and the fourth virtual line when a point closest to the third virtual line on the outer periphery is defined as a second virtual point (36). And

  With this configuration, the first auxiliary pulley is disposed in a direction substantially perpendicular to the cylinder axis with respect to the crank pulley, and the first virtual point is located between the first virtual line and the second virtual line. By doing so, the direction of the belt load with respect to the crank pulley can be made substantially orthogonal to the cylinder axis, so that it is possible to suppress the sound generated during driving of the internal combustion engine. Further, the power transmission can be ensured by increasing the winding angle with respect to the crank pulley. On the other hand, by arranging the center of the third accessory pulley in the triangle, the diameter of the third accessory pulley is increased without causing interference with the transmission belt between the first accessory pulley and the second accessory pulley. Therefore, there is no need to provide an idler pulley for changing the belt track between the first auxiliary pulley and the second auxiliary pulley.

  In addition, the tension pulley is not connected to the belt slack side of the crank pulley, but is arranged on the belt entry side of the second accessory pulley and the belt exit side of the third accessory pulley, so that the second auxiliary pulley is arranged. The distance in the cylinder axis direction between the machine and the third auxiliary machine is ensured, and the distance in the cylinder axis direction from the first auxiliary machine pulley to the second auxiliary machine pulley can be shortened. Therefore, the apparatus can be reduced in size. Moreover, when the second virtual point is located between the third virtual line and the fourth virtual line, a winding angle with respect to the third auxiliary pulley can be ensured. In addition, since the winding angle with respect to the tension pulley can be increased, the stroke of the auto tensioner necessary for applying a predetermined tension can be reduced, and the auto tensioner can be reduced in size.

  According to another aspect of the present invention, the transmission belt may be a V-belt (15) whose outer surface is a flat surface, and the third auxiliary machine may be a water pump (23). According to this configuration, it is possible to ensure the frictional force necessary to drive the first to third auxiliary machines with one narrow transmission belt. In addition, the outer surface of the V-belt is wound around the third accessory pulley, but the slip between the third accessory pulley and the transmission belt is suppressed by making the third accessory pulley a pump pulley with a relatively small driving force. it can.

  Further, according to one aspect of the present invention, the auto tensioner can be configured to be disposed inside the transmission belt when viewed in the axial direction of the crankshaft. According to this configuration, the apparatus can be reduced in size.

  As described above, according to the present invention, the direction of the belt load applied to the crank pulley is made different from the direction of the cylinder axis to suppress the generation of hitting sound, and it is possible to reduce the size with the minimum necessary configuration while ensuring the power transmission. An auxiliary drive device can be provided.

Front view of auxiliary machine drive device according to the embodiment II-II sectional view in FIG. Arrangement explanatory drawing of the auxiliary machine drive device shown in FIG.

  Hereinafter, an embodiment of an accessory drive device 1 according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the accessory drive device 1 is attached to an internal combustion engine for vehicles (hereinafter referred to as “engine E”). The engine E includes an engine body 2 composed of a cylinder block and a cylinder head that define a cylinder and a crank room, a chain cover 3 that is fastened to a side surface of the engine body 2 to cover a timing chain, and a lower end of the engine body 2 A four-cycle in-line multi-cylinder gasoline engine including an oil pan 4 and a cylinder head cover 5 fastened to the upper end of the engine main body 2. The cylinder axis 6 indicated by a one-dot chain line is slightly inclined toward the rear of the vehicle. Installed. In FIG. 1, the engine E mounted on the vehicle is shown with the vertical direction of the paper as the vertical direction. In the following, the piston sliding direction from the bottom dead center side to the top dead center side in the cylinder axis 6 direction is defined as the upward direction A, and the piston from the piston top dead center side to the bottom dead center side in the cylinder axis 6 direction. The sliding direction will be described as a descending direction B.

  A crankshaft 7 extending in the cylinder row direction is provided below the engine E, and a crank pulley 10 is provided at one end of the crankshaft 7 protruding from the chain cover 3. An alternator 22 (second auxiliary machine), a water pump 23 (third auxiliary machine) and an air conditioner compressor 21 (first auxiliary machine) are mounted on the front surface of the engine E along the cylinder row direction in order from the top. It is attached to the engine main body 2 via. On the rotation plane of the crank pulley 10, an alternator pulley 12 (second auxiliary pulley), a pump pulley 13 (third auxiliary pulley) and a compressor pulley 11 (first auxiliary pulley) for driving these auxiliary devices 21 to 23 are driven. Machine pulleys) are arranged respectively.

  An endless V-belt 15 is wound around the crank pulley 10. As shown in FIG. 2, the V-belt 15 is a V-ribbed belt in which seven V-shaped ribs 15a are continuously provided on the inner surface 15i side and the outer surface 15o is a flat surface, and the inner surface 15i is the crank pulley 10. Is wound around the crank pulley 10 so as to be in contact with the outer peripheral surface. Seven grooves 10a having a shape complementary to the seven ribs 15a are formed on the outer peripheral surface of the crank pulley 10, and when the tension is applied to the V-belt 15, the ribs 15a bite into the grooves 10a and the crank pulley 10 And the frictional force between the V belt 15 increases.

  The crank pulley 10 rotates clockwise as indicated by an arrow in FIG. The V-belt 15 wound around the crank pulley 10 extends in two directions, a so-called tension side that allows the belt to enter from the lower side of the crank pulley 10 and a so-called slack side that causes the belt to exit from the upper side of the crank pulley 10. Connected to form a ring. The V belt 15 is wound around the compressor pulley 11, the alternator pulley 12, and the pump pulley 13 in this order from the crank pulley 10 to the belt entry side (tension side). The crank pulley 10, the compressor pulley 11, the alternator pulley 12, the pump pulley 13, and the V belt 15 constitute an auxiliary machine driving device 1 that drives the auxiliary machines 21 to 23 by the rotation of the crankshaft 7.

  The compressor pulley 11 is disposed in a direction substantially perpendicular to the cylinder axis 6 with respect to the crank pulley 10 and is in rolling contact with the inner surface 15 i of the V pulley 15 on the belt entrance side of the crank pulley 10. Here, the fact that the compressor pulley 11 is arranged in a direction substantially orthogonal to the cylinder axis 6 with respect to the crank pulley 10 means that the crank pulley 10 and the compressor in the V-belt 15 have a compressor effect that will be described later. This means that the portion spanned over the pulley 11 extends in a direction substantially perpendicular to the cylinder axis 6. The extending direction of the V-belt 15 varies depending on the diameters of the crank pulley 10 and the compressor pulley 11 and the distance between the two, but the dimensions of the general automobile engine and the sizes of the crank pulley and auxiliary pulley used therefor are determined. In consideration, the center 11x of the compressor pulley 11 may be generally positioned between the rising direction A side end and the descending direction B side end on the outer peripheral edge of the crank pulley 10 in the cylinder axis 6 direction.

  The alternator pulley 12 is arranged on the ascending direction A side of the compressor pulley 11 in the cylinder axis 6 direction, and is in rolling contact with the inner surface 15 i of the V pulley 15 on the belt entrance side of the compressor pulley 11.

  The pump pulley 13 is disposed between the compressor pulley 11 and the alternator pulley 12 in the cylinder axis 6 direction, and is in rolling contact with the outer surface 15 o of the V belt 15 on the belt entry side of the alternator pulley 12 and the belt exit side of the crank pulley 10. .

  The accessory driving device 1 further includes a tension pulley 14 that is in rolling contact with the inner surface 15 i of the V-belt 15 on the belt entry side of the alternator pulley 12 and the belt pulley side of the pump pulley 13. The tension pulley 14 is rotatably supported at one end of a bell crank 16 whose central portion is swingably held by a mounting bracket. The other end of the bell crank 16 is connected to the other end of an auto tensioner 17 that includes a hydraulic damper mechanism and has one end attached to a mounting bracket. When the auto tensioner 17 urges the bell crank 16 in the direction of pushing the other end, the tension pulley 14 urges the V belt 15 to expand outward, thereby applying tension to the V belt 15. The bell crank 16 and the auto tensioner 17 are also arranged inside the V-belt 15 in the front view (FIG. 1) of the accessory driving device 1, similarly to the tension pulley 14.

  The arrangement of the pulleys 10 to 14 will be described in more detail with reference to FIG. The center 13x of the pump pulley 13 is arranged in a triangle 30 connecting the center 10x of the crank pulley 10, the center 11x of the compressor pulley 11, and the center 12x of the alternator pulley 12.

A straight line defined by a portion of the V-belt 15 that is stretched between the crank pulley 10 and the compressor pulley 11, that is, a common portion that is in contact with each portion on the lowering direction B side of the outer peripheral edge of the crank pulley 10 and the outer peripheral edge of the compressor pulley 11. A tangent line is a first imaginary line 31, a tangent line that is parallel to the first imaginary line 31 and is in contact with a portion on the outer peripheral edge of the crank pulley 10 on the rising direction A side is a second imaginary line 32, If the point closest to the first imaginary line 31 on the periphery is the first imaginary point 35, the crank pulley 10 is arranged such that the first imaginary point 35 is located between the first imaginary line 31 and the second imaginary line 32. A compressor pulley 11 and a pump pulley 13 are arranged.

  On the other hand, a straight line defined by a portion of the V-belt 15 that spans between the compressor pulley 11 and the alternator pulley 12, that is, each of the outer peripheral edge of the compressor pulley 11 and the outer peripheral edge of the alternator pulley 12 on the side far from the crank pulley 10. A common tangent line in contact with the part is referred to as a third imaginary line 33, and a tangent line that is parallel to the third imaginary line 33 and is in contact with the part near the crank pulley 10 on the outer peripheral edge of the tension pulley 14 is defined as a fourth imaginary line 34. When the point closest to the third virtual line 33 on the outer peripheral edge of the pump pulley 13 is the second virtual point 36, the second virtual point 36 is located between the third virtual line 33 and the fourth virtual line 34. In addition, a compressor pulley 11, an alternator pulley 12, a pump pulley 13 and a tension pulley 14 are arranged.

  Thus, the compressor pulley 11 is arranged in a direction substantially perpendicular to the cylinder axis 6 with respect to the crank pulley 10, and the first imaginary point 35 is located between the first imaginary line 31 and the second imaginary line 32. As a result, it is possible to secure a large transmission angle with respect to the crank pulley 10 and to ensure that the direction of the belt load with respect to the crank pulley 10 is substantially perpendicular to the cylinder axis 6. It is possible to suppress the hitting sound generated inside. Since the center 13x of the pump pulley 13 is disposed in the triangle 30, the diameter of the pump pulley 13 can be increased without causing interference with the V-belt 15 between the compressor pulley 11 and the alternator pulley 12, so that the compressor pulley It is not necessary to provide an idler pulley between the 11 and the alternator pulley 12 to change the track of the V belt 15.

  The tension pulley 14 is not connected to the slack side of the crank pulley 10 but is disposed on the belt entry side of the alternator pulley 12 and on the belt exit side of the pump pulley 13, so that the alternator 22 and the water pump 23 are arranged. And the distance in the cylinder axis direction from the compressor pulley 11 to the alternator pulley 12 can be shortened. Therefore, downsizing of the accessory drive device 1 is realized. Further, since the second virtual point 36 is located between the third virtual line 33 and the fourth virtual line 34, a winding angle with respect to the pump pulley 13 is ensured. In addition, since the winding angle with respect to the tension pulley 14 is increased, the stroke of the auto tensioner 17 necessary for applying a predetermined tension is reduced, and the auto tensioner 17 can be downsized.

  On the other hand, the transmission belt constituting the auxiliary drive unit 1 is the V-belt 15, so that the frictional force necessary to drive the three auxiliary devices 21 to 23 is secured by one narrow V-belt 15. In addition, since the auxiliary pulley around which the outer surface 15o of the V belt 15 is wound is the pump pulley 13 having a relatively small driving force, slip between the outer surface 15o of the V belt 15 and the outer peripheral surface of the pump pulley 13 is also suppressed. Furthermore, since the auto tensioner 17 is disposed inside the V-belt 15 when the crankshaft 7 is viewed in the axial direction, the accessory drive device 1 is downsized.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above embodiment, the present invention is applied to an in-line multi-cylinder gasoline engine, but it is also possible to apply to other internal combustion engines. Moreover, in the said embodiment, although the auxiliary machine drive device 1 is driving the three auxiliary machines of the compressor 21, the alternator 22, and the water pump 23 which are arrange | positioned in order from the crank pulley 10 to the tension | tensile | strength side, May be replaced or other auxiliary machines may be driven. In the above embodiment, the auto tensioner 17 having a hydraulic damper mechanism is used. However, the auto tensioner 17 is not limited to the hydraulic type, and other types of auto tensioners such as a friction type may be used. In addition, the specific configuration, arrangement, and quantity of each device and member can be changed as appropriate without departing from the spirit of the present invention. On the other hand, all the constituent elements of the accessory driving device 1 according to the present invention shown in the above embodiment are not necessarily essential, and can be appropriately selected as long as they do not depart from the gist of the present invention.

1 Auxiliary machine drive 6 Cylinder axis 7 Crankshaft 10 Crank pulley 11 Compressor pulley (first auxiliary pulley)
12 Alternator pulley (second auxiliary pulley)
13 Pump pulley (3rd auxiliary pulley)
10x, 11x, 12x, 13x Center of each pulley 10-13 14 Tension pulley 15 V belt (power transmission belt)
15i Inner surface 15o Outer surface 17 Auto tensioner 21 Compressor (first auxiliary machine)
22 Alternator (second auxiliary machine)
23 Water pump (3rd auxiliary machine)
30 triangle 31 first virtual line 32 second virtual line 33 third virtual line 34 fourth virtual line 35 first virtual point 36 second virtual point A ascending direction B descending direction

Claims (5)

A crank pulley provided at one end of the crankshaft;
A first accessory pulley that drives a first accessory disposed in a direction substantially perpendicular to a cylinder axis with respect to the crank pulley;
A second auxiliary pulley that drives a second auxiliary machine arranged on the ascending side in the cylinder axial direction from the first auxiliary pulley;
A third accessory pulley that drives a third accessory disposed between the first accessory pulley and the second accessory pulley in a cylinder axial direction;
A tension pulley disposed between the second auxiliary pulley and the third auxiliary pulley in the cylinder axial direction and biased by an auto tensioner;
In order from the crank pulley to the tension side, the first auxiliary pulley, the second auxiliary pulley, the tension pulley and the third auxiliary pulley are wound around the crank pulley, the first auxiliary pulley, An auxiliary machine driving device for an internal combustion engine, comprising: an endless transmission belt for contacting an inner surface of the second auxiliary pulley and the tension pulley with an inner surface of the second auxiliary pulley and the tension pulley; ,
The center of the third auxiliary pulley is arranged in a triangle connecting the centers of the crank pulley, the first auxiliary pulley and the second auxiliary pulley,
A straight line defined by the transmission belt between the crank pulley and the first auxiliary pulley is defined as a first imaginary line, and the crank pulley at a portion on the outer peripheral edge on the side opposite to the first imaginary line. When the tangent parallel to the first imaginary line is the second imaginary line and the point closest to the first imaginary line on the outer peripheral edge of the third auxiliary pulley is the first imaginary point, the first imaginary point Is located between the first imaginary line and the second imaginary line,
A straight line defined by the transmission belt between the first auxiliary pulley and the second auxiliary pulley is defined as a third imaginary line, and a portion of the tension pulley on the outer peripheral edge close to the crank pulley. When the tangent parallel to the third imaginary line is the fourth imaginary line and the point closest to the third imaginary line on the outer peripheral edge of the third auxiliary pulley is the second imaginary point, the second imaginary line A point is located between the third imaginary line and the fourth imaginary line ;
An auxiliary machine driving apparatus for an internal combustion engine, wherein the auto tensioner is disposed inside the transmission belt as viewed in the axial direction of the crankshaft . All the auxiliary machines driven by the transmission belt including the first auxiliary machine, the second auxiliary machine, and the third auxiliary machine are arranged on one side with respect to the cylinder axis in the axial direction view of the crankshaft. The accessory drive apparatus for an internal combustion engine according to claim 1, wherein The said auto tensioner is arrange | positioned inside the triangle which connected each center of the said crank pulley, the said 1st accessory pulley, and the said 2nd accessory pulley, The Claim 1 or Claim 2 characterized by the above-mentioned. Auxiliary machine drive device for internal combustion engine. 4. The auxiliary drive apparatus for an internal combustion engine according to claim 3, wherein the tension pulley is disposed outside the triangle. The transmission belt is a V-belt whose outer surface forms a flat surface,
The auxiliary drive apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein the third auxiliary machine is a water pump.

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