Belt transmission device for engine

Abstract

To provide a belt transmission device of an engine capable of preventing a belt from loosening while downsizing the engine by efficiently arranging an auto tensioner, in a configuration for driving a plurality of auxiliary machines arranged on the engine in which a cylinder shaft is inclined from a crank pulley with a single belt.SOLUTION: A support bracket 40 has: a first fixing part 41 and a second fixing part 42 fixed to an oil pan 6; auxiliary machine attachment parts 43, 44 to which an air-conditioning compressor 12 and a motor generator 14 are attached; and a front wall part 45 continuous with these parts. The air-conditioning compressor 12 is arranged below the auxiliary machine attachment parts 43, 44. The motor generator 14 is arranged above the auxiliary machine attachment parts 43, 44. A connection part 35 is attached to the front wall part 45. A first tensioner pulley 31 is arranged on a first belt span 16A, and a second tensioner pulley is arranged on a second belt span 16B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a belt transmission for an engine. [Background technology]

[0002] Patent Document 1 discloses an accessory mounting structure for an internal combustion engine, which is configured to reduce the size of the internal combustion engine and includes an accessory and a bracket that adjusts the tension of an endless belt that is passed over the accessory. The accessory mounting structure for an internal combustion engine described in Patent Document 1 includes an internal combustion engine mounted with the axis of the cylinder bore tilted, a pulley that is rotated by an endless belt that is passed over a crank pulley, a first accessory (alternator) that has a connecting part that is swingably attached around a fixed part that is directly fixed to the internal combustion engine as a fulcrum, a second accessory (such as an air conditioner compressor) that has a pulley that rotates in conjunction with the rotation of the crank pulley, and a bracket that adjusts the tension of the endless belt. The bracket has a fixed end that is disposed between the pulleys, a connecting end that is connected to the first accessory, and a main body that is disposed from the fixed end to the connecting end, passing between the accessory pulleys. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-160955 Summary of the Invention [Problem to be solved by the invention]

[0004] In the mounting structure for accessories for an internal combustion engine described in Patent Document 1, if the first accessory is changed to a motor-generator capable of generating electricity and powering the engine, the tension in the belt changes depending on whether the motor-generator is generating electricity or powering the engine, making it necessary to add an auto-tensioner to prevent the belt from loosening. Furthermore, because the air conditioner compressor is located downstream of the crank pulley in the direction of belt travel, and the motor-generator is located downstream of the compressor, the motor-generator is positioned higher, which helps prevent damage from flooding. However, because the compressor, which has a greater driving load than the motor-generator, is located downstream of the crank pulley in the direction of belt travel, there is a problem in that the belt between the crank pulley and the compressor is prone to loosening.

[0005] The conventional technology described in Patent Document 1 does not include an auto-tensioner to prevent the belt from loosening, and does not consider the placement of an auto-tensioner if one is provided. This creates the problem that the auto-tensioner cannot be efficiently placed to reduce the engine size while still preventing the belt from loosening.

[0006] The present invention has been made in light of the above-mentioned circumstances, and aims to provide a belt transmission system for an engine in which a single belt is used to drive multiple accessories mounted on an engine with an inclined cylinder axis from a crank pulley, and which can efficiently position an autotensioner to reduce the engine size while preventing belt slack. [Means for solving the problem]

[0007] the first arm and the second arm swinging about the connecting part; a first tensioner pulley attached to the tip of the first arm; and a second tensioner pulley attached to the tip of the second arm, the first tensioner pulley being attached to the tip of the second arm, and the second tensioner pulley being urged in a direction to move closer to each other. a support bracket having a first fixing part fixed to a portion of the oil pan above the recessed part, a second fixing part fixed to the recessed part, an accessory mounting part to which the air conditioning compressor and the motor generator are attached, and a front wall part continuous with the first fixing part, the second fixing part, and the accessory mounting part, and when viewed from one end side of the crankshaft, the front wall part is located within an area formed by connecting the first fixing part, the second fixing part, and the accessory mounting part. the air conditioning compressor is disposed below the accessory mounting portion, the motor generator is disposed above the accessory mounting portion, the connecting portion is attached to the front wall portion, the first tensioner pulley is disposed on a first belt span between the crank pulley and the first pulley and presses the outer peripheral surface of the belt, and the second tensioner pulley is disposed on a second belt span between the crank pulley and the second pulley and presses the outer peripheral surface of the belt. [Effects of the Invention]

[0008] As described above, according to the present invention, in a configuration in which a single belt drives multiple accessories mounted on an engine with an inclined cylinder axis from a crank pulley, it is possible to provide a belt transmission device for an engine that can efficiently position an autotensioner to reduce the engine size while preventing belt slack. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of an engine equipped with a belt transmission device for an engine according to one embodiment of the present invention. [Figure 2] FIG. 2 is a right side view of the bottom of an engine equipped with a belt transmission device for an engine according to one embodiment of the present invention. [Figure 3] 3 is a cross-sectional view of the engine provided with the belt transmission device of the engine shown in FIG. 2, taken along the line III-III. [Figure 4] FIG. 4 is a perspective view of the bottom of an engine equipped with a belt transmission device for an engine according to one embodiment of the present invention. [Figure 5] FIG. 5 is a front view of the bottom of an engine equipped with a belt transmission device for an engine according to one embodiment of the present invention. [Figure 6] FIG. 6 is a plan view of the bottom of an engine equipped with a belt transmission device for an engine according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] An engine belt transmission device according to one embodiment of the present invention includes: an engine body mounted on a vehicle with a cylinder axis tilted so that one side of an oil pan faces diagonally upward; a crank pulley connected to a crankshaft of the engine body; an air conditioning compressor having a first pulley and disposed above the oil pan on one end side of the crankshaft; a motor generator having a second pulley and disposed above the air conditioning compressor on one end side of the crankshaft; an endless belt wound around the crank pulley, the first pulley, and the second pulley; a connecting portion attached to the engine body; first and second arms that swing around the connecting portion; a first tensioner pulley attached to a tip of the first arm; and a second tensioner pulley attached to a tip of the second arm, the autotensioner biasing the first tensioner pulley and the second tensioner pulley in directions that bring them closer to each other. the oil pan has a recess formed in the lower part of one side thereof so as to approach the cylinder axis, and the support bracket has: a first fixed part fixed to a position on the oil pan above the recess, a second fixed part fixed to the recess, an accessory mounting part to which an air conditioning compressor and a motor generator are attached, and a front wall part continuous with the first fixed part, the second fixed part, and the accessory mounting part, and when viewed from one end of the crankshaft, the front wall part is located within an area formed by connecting the first fixed part, the second fixed part, and the accessory mounting part, the air conditioning compressor is located below the accessory mounting part, the motor generator is located above the accessory mounting part, the connecting part is attached to the front wall part, a first tensioner pulley is located on a first belt span between the crank pulley and the first pulley and presses the outer peripheral surface of the belt, and a second tensioner pulley is located on a second belt span between the crank pulley and the second pulley and presses the outer peripheral surface of the belt. As a result, in an engine belt transmission device according to one embodiment of the present invention, in a configuration in which a single belt drives multiple accessories arranged in an engine with an inclined cylinder axis from a crank pulley, the autotensioner can be efficiently positioned to reduce the size of the engine while preventing belt slack. [Example]

[0011] An engine belt transmission device according to an embodiment of the present invention will be described below with reference to the drawings. Figures 1 to 6 are views showing an engine belt transmission device according to an embodiment of the present invention. In Figures 1 to 6, the up-down, front-rear, left-right directions refer to the front-rear direction of the vehicle, the left-right direction of the vehicle (vehicle width direction) and the up-down direction of the vehicle (vehicle height direction).

[0012] 1, a vehicle 1 is equipped with an engine 20. The engine 20 is supported by a body 1A of the vehicle 1.

[0013] The engine 20 includes an engine body 2. An oil pan 6 for storing oil is provided at the bottom of the engine body 2. The engine body 2 includes a cylinder block 5 disposed above the oil pan 6, a cylinder head 4 disposed above the cylinder block 5, and a head cover 3 disposed above the cylinder head 4. A cylindrical cylinder (not shown) is formed in the cylinder block 5. The central axis of the cylinder is called the cylinder axis 2A.

[0014] The engine body 2 is mounted on the vehicle 1 with the cylinder axis 2A tilted so that one side 6B of the oil pan 6 faces diagonally upward. One side 6B of the oil pan 6 is the surface that forms the upper surface of the oil pan 6 in the engine body 2 that is disposed in a tilted position, and refers to the surface that slopes downward to the right on the right side of the oil pan 6. The engine body 2 is mounted on the vehicle 1 with the cylinder axis 2A tilted downward to the right.

[0015] The engine 20 includes an intake manifold 10 on top of the cylinder block 5 and the cylinder head 4. The engine 20 includes a water pump 11 on the left end of the cylinder block 5.

[0016] The engine 20 is equipped with a crank pulley 8 connected to a crankshaft 7 of the engine body 2. The crankshaft 7 and the crank pulley 8 rotate clockwise when the engine 20 is viewed from the front as shown in FIG.

[0017] The engine 20 has a first pulley 13 and is equipped with an air conditioning compressor 12 that is disposed above the oil pan 6 on one end side of the crankshaft 7. The one end side of the crankshaft 7 is the front end side of the crankshaft 7, which is the front side of the engine body 2 in FIG.

[0018] The engine 20 has a second pulley 15 and is equipped with a motor generator 14 that is arranged above the air conditioning compressor 12 on one end side of the crankshaft 7. The motor generator 14 is a rotating electric machine that functions as both a generator and an electric motor.

[0019] The engine 20 is equipped with an endless belt 16 wound around a crank pulley 8, a first pulley 13, and a second pulley 15. In Fig. 1, when the crank pulley 8 rotates clockwise, the belt 16 runs clockwise, and the first pulley 13 and the second pulley 15 rotate clockwise.

[0020] The engine 20 is equipped with an auto-tensioner 30. The auto-tensioner 30 has a connecting portion 35 attached to the engine body 2, a first arm 33 and a second arm 34 that swing around the connecting portion 35, a first tensioner pulley 31 attached to the tip of the first arm 33, and a second tensioner pulley 32 attached to the tip of the second arm 34, and biases the first tensioner pulley 31 and the second tensioner pulley 32 in directions that bring them closer to each other. The auto-tensioner 30 has a biasing member such as a spring (not shown) that biases the first tensioner pulley 31 and the second tensioner pulley 32 in directions that bring them closer to each other.

[0021] The engine 20 is provided with a support bracket 40. The air conditioning compressor 12, the motor generator 14, and the autotensioner 30 are supported on the engine body 2 by the support bracket 40.

[0022] As shown in Figures 3, 4, 5, and 6, a recessed portion 6A is formed in the lower portion of one side surface 6B of the oil pan 6, recessed so as to approach the cylinder axis 2A (see Figure 1). The oil pan 6 is wide at a flange-shaped joint (not shown) where it joins with the cylinder block 5 at its upper portion, and narrows below this joint. This narrow portion is the recessed portion 6A. A base portion 6C consisting of a boss and ribs for fixing a part of the support bracket 40 is formed in the recessed portion 6A. The support bracket 40 has a boss-shaped fixing portion 46, and is fixed to the base portion 6C of the recessed portion 6A at this fixing portion 46.

[0023] The support bracket 40 has a first fixing portion 41 fixed to a position above the recessed portion 6A in the oil pan 6, a second fixing portion 42 fixed to the recessed portion 6A, accessory mounting portions 43 and 44 to which the air conditioning compressor 12 and the motor generator 14 are attached, and a front wall portion 45 continuous with the first fixing portion 41, the second fixing portion 42 and the accessory mounting portions 43 and 44.

[0024] The air conditioning compressor 12 is attached to an accessory mounting portion 43 of the support bracket 40. The motor generator 14 is attached to an accessory mounting portion 44 of the support bracket 40. The accessory mounting portion 43 and the accessory mounting portion 44 are disposed so close to each other that they can be considered to be in substantially the same position.

[0025] As shown in Figure 3, when viewed from one end side of the crankshaft 7 (see Figure 1), the front wall portion 45 is located within a triangular area formed by connecting the first fixing portion 41, the second fixing portion 42, and the accessory mounting portions 43, 44.

[0026] The air conditioning compressor 12 is disposed below an accessory mounting portion 43 of the support bracket 40. The motor generator 14 is disposed above an accessory mounting portion 44 of the support bracket 40.

[0027] As shown in FIG. 2, the connecting portion 35 of the autotensioner 30 is attached to the front wall portion 45 of the support bracket 40 .

[0028] 1, the first tensioner pulley 31 is disposed on the first belt span 16A between the crank pulley 8 and the first pulley 13, and presses against the outer circumferential surface of the belt 16. The second tensioner pulley 32 is disposed on the second belt span 16B between the crank pulley 8 and the second pulley 15, and presses against the outer circumferential surface of the belt 16.

[0029] Because the belt 16 runs clockwise, when the motor generator 14 is generating power, the first belt span 16A located downstream of the crank pulley 8 in the running direction of the belt 16 (toward the air conditioning compressor 12) becomes the slack belt span where tension decreases, and the second belt span 16B located upstream of the crank pulley 8 in the running direction of the belt 16 (toward the motor generator 14) becomes the tight belt span where tension increases. On the other hand, when the motor generator 14 is powering, both the first belt span 16A and the second belt span 16B may become the slack belt span. The autotensioner 30 functions to suppress fluctuations in tension at each portion of the belt 16 due to the operating state of the accessories.

[0030] The engine body 2 has an engine-side mounting portion 2B that is disposed above the support bracket 40 in the direction along the cylinder axis 2A. The motor-generator 14 has a first mounting portion 14A that is attached to the engine-side mounting portion 2B of the engine body 2.

[0031] The first mounting portion 14A and the engine-side mounting portion 2B are formed in the shape of plates that protrude in the radial direction of the motor-generator 14. The first mounting portion 14A and the engine-side mounting portion 2B are connected to each other by a first fastener 51, which is a bolt that extends parallel to the crankshaft 7.

[0032] As shown in FIG. 3, the motor generator 14 has a second mounting portion 14B that is mounted to the accessory mounting portion 44 of the support bracket 40.

[0033] The second mounting portion 14B and the accessory mounting portion 44 are formed in a boss shape extending in a direction intersecting the upper surface of the oil pan 6. The second mounting portion 14B and the accessory mounting portion 44 are connected to each other by a second fastener 52 consisting of a bolt that passes through the second mounting portion 14B and the accessory mounting portion 44.

[0034] The air conditioning compressor 12 has an upper mounting portion 12A that is attached to the accessory mounting portion 43 of the support bracket 40. The upper mounting portion 12A and the accessory mounting portion 43 are formed in the shape of a plate that protrudes in the radial direction of the air conditioning compressor 12. The upper mounting portion 12A and the accessory mounting portion 43 are connected to each other by a fastener 53 made of a bolt that extends parallel to the crankshaft 7.

[0035] The air conditioning compressor 12 has a lower mounting portion 12B that is attached to the lower portion of the recessed portion 6A of the oil pan 6. The lower mounting portions 12B are interconnected by a fastener (not shown) made of a bolt that extends parallel to the crankshaft 7.

[0036] 1, the engine 20 includes an idler pulley 17. The idler pulley 17 is disposed in the third belt span 16C between the first pulley 13 and the second pulley 15, and presses the outer peripheral surface of the belt 16.

[0037] 2, the idler pulley 17 is attached to the second attachment portion 14B of the motor generator 14. More specifically, the second attachment portion 14B is provided with a support portion 14C that rotatably supports the idler pulley 17, and the idler pulley 17 is attached to the second attachment portion 14B via the support portion 14C.

[0038] As described above, in this embodiment, a recessed portion 6A recessed toward the cylinder axis 2A is formed in the lower portion of one side surface 6B of the oil pan 6. The engine 20 also includes a support bracket 40 having a first fixing portion 41 fixed to a portion of the oil pan 6 above the recessed portion 6A, a second fixing portion 42 fixed to the recessed portion 6A, accessory mounting portions 43, 44 to which the air conditioning compressor 12 and the motor-generator 14 are attached, and a front wall portion 45 continuous with the first fixing portion 41, the second fixing portion 42, and the accessory mounting portions 43, 44. When viewed from one end of the crankshaft 7, the front wall portion 45 is located within a region formed by connecting the first fixing portion 41, the second fixing portion 42, and the accessory mounting portions 43, 44. The air conditioning compressor 12 is located below the accessory mounting portions 43, 44, and the motor-generator 14 is located above the accessory mounting portions 43, 44. In addition, the connecting portion 35 is attached to the front wall portion 45, the first tensioner pulley 31 is arranged in the first belt span 16A between the crank pulley 8 and the first pulley 13 and presses the outer surface of the belt 16, and the second tensioner pulley 32 is arranged in the second belt span 16B between the crank pulley 8 and the second pulley 15 and presses the outer surface of the belt 16.

[0039] In this way, by disposing the first tensioner pulley 31 on the first belt span 16A between the crank pulley 8 and the first pulley 13, the first tensioner pulley 31 can appropriately apply tension to the first belt span 16A, which is located downstream of the crank pulley 8 in the belt running direction and is therefore prone to loosening due to a decrease in tension caused by the load torque when the air conditioning compressor 12 is operating, and therefore can prevent loosening of the belt 16.

[0040] Furthermore, by disposing the second tensioner pulley 32 on the second belt span 16B between the second pulley 15 and the crank pulley 8, the second belt span 16B is located upstream of the crank pulley 8 in the belt running direction, and therefore the tension on the second belt span 16B is reduced when the motor generator 14 is powered, making it prone to loosening. Therefore, the second tensioner pulley 32 can appropriately apply tension to the second belt span 16B, thereby preventing loosening of the belt 16.

[0041] Furthermore, because the first tensioner pulley 31 and the second tensioner pulley 32 are biased toward each other by a biasing member inside the autotensioner 30, appropriate tension can be applied to either the first belt span 16A or the second belt span 16B, whichever has lower tension, and the tension of the first belt span 16A and the tension of the second belt span 16B can be equalized, thereby preventing slack in the belt 16.

[0042] Furthermore, by attaching the first fixing portion 41 and the second fixing portion 42 of the support bracket 40 to the oil pan 6, by disposing the air conditioning compressor 12 below the accessory mounting portions 43 and 44 of the support bracket 40, by disposing the motor-generator 14 above the support bracket 40, and by attaching the connecting portion 35 of the auto-tensioner 30 to the front wall portion 45 of the support bracket 40, the auto-tensioner 30 with the connecting portion 35 can be positioned in a position that is advantageous for adjusting the tension of the belt 16, and by storing the auto-tensioner 30 compactly in the gap between the air-conditioning compressor 12 and the motor-generator 14 on the front side of the engine 20. Therefore, the auto-tensioner 30 can be positioned efficiently, allowing the engine 20 to be made more compact.

[0043] As a result, in a configuration in which multiple accessories arranged on an engine 20 with an inclined cylinder axis 2A are driven by a single belt 16 from a crank pulley 8, the autotensioner 30 can be efficiently positioned to reduce the size of the engine 20 while preventing slack in the belt 16.

[0044] In this embodiment, the engine body 2 has an engine-side mounting portion 2B that is located above the support bracket 40 in the direction along the cylinder axis 2A, and the motor-generator 14 has a first mounting portion 14A that is attached to the engine-side mounting portion 2B and a second mounting portion 14B that is attached to the accessory mounting portions 43, 44. The first mounting portion 14A and the engine-side mounting portion 2B are formed in a plate shape that protrudes in the radial direction of the motor-generator 14 and are connected to each other by a first fastener 51 that extends parallel to the crankshaft 7, and the second mounting portion 14B and the accessory mounting portions 43, 44 are formed in a boss shape that extends in a direction intersecting the upper surface of the oil pan 6 and are connected to each other by a second fastener 52 that penetrates the second mounting portion 14B and the accessory mounting portions 43, 44.

[0045] This allows the second mounting portion 14B and the accessory mounting portions 43, 44 to be positioned away from the connecting portion 35 of the auto tensioner 30, thereby preventing the installation position of the auto tensioner 30 from being restricted by the position or shape of the second mounting portion 14B.

[0046] In addition, this embodiment is provided with an idler pulley 17 that is arranged in the third belt span 16C between the first pulley 13 and the second pulley 15 and presses the outer surface of the belt 16, and the idler pulley 17 is attached to the second mounting portion 14B.

[0047] This allows the idler pulley 17 to increase the winding angle of the belt 16 around the first pulley 13 and the second pulley 15, thereby preventing slippage of the belt 16. In addition, by moving the idler pulley 17 along the central axis of the boss-shaped second mounting portion 14B, the idler pulley 17 can be positioned at an appropriate position.

[0048] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0049] 1 vehicle 2 Engine body 2A Cylinder shaft 2B Engine side mounting part 6 Oil pan 6A Recess 6B One side 7 crankshaft 8 crank pulley 12 Air conditioning compressor 13 First pulley 14 Motor generator 14A First mounting part 14B Second mounting part 14C Support part 15 No. 2 pulley 16 Belt 16A First Belt Span 16B Second Belt Span 16C 3rd Belt Span 17 Idler pulley 20 Engine 30 Auto tensioner 31 No. 1 tensioner pulley 32 No. 2 tensioner pulley 33 First Arm 34 Second Arm 35 Connecting part 40 Support bracket 41 1st fixed part 42 Second fixed part 43 Auxiliary equipment mounting section 44 Auxiliary equipment mounting section 45 Front wall 51 First fastener 52 Second fastener

Claims

1. an engine body mounted on a vehicle with a cylinder axis tilted so that one side of the oil pan faces obliquely upward; a crank pulley connected to a crankshaft of the engine body; an air conditioning compressor having a first pulley and disposed above the oil pan on one end side of the crankshaft; a motor generator having a second pulley and disposed above the air conditioning compressor on one end side of the crankshaft; an endless belt wound around the crank pulley, the first pulley, and the second pulley; a first arm and a second arm that swing around the connecting part; a first tensioner pulley attached to a tip of the first arm; and a second tensioner pulley attached to a tip of the second arm, the autotensioner biasing the first tensioner pulley and the second tensioner pulley in directions that bring them closer to each other, a recessed portion recessed toward the cylinder axis is formed in a lower portion of one side surface of the oil pan; a support bracket having a first fixing portion fixed to a portion of the oil pan above the recessed portion, a second fixing portion fixed to the recessed portion, an accessory mounting portion to which the air conditioning compressor and the motor generator are attached, and a front wall portion continuous with the first fixing portion, the second fixing portion, and the accessory mounting portion, the front wall portion is disposed within a region formed by connecting the first fixing portion, the second fixing portion, and the accessory mounting portion when viewed from one end side of the crankshaft, the air conditioning compressor is disposed below the accessory mounting portion, the motor generator is disposed above the accessory mounting portion, the connecting portion is attached to the front wall portion, the first tensioner pulley is disposed on a first belt span between the crank pulley and the first pulley and presses an outer peripheral surface of the belt; a second tensioner pulley disposed on a second belt span between the crank pulley and the second pulley and pressing against the outer peripheral surface of the belt;

2. the engine body has an engine-side mounting portion disposed above the support bracket in a direction along the cylinder axis, the motor generator has a first mounting portion attached to the engine side mounting portion and a second mounting portion attached to the accessory mounting portion, the first mounting portion and the engine-side mounting portion are formed in a plate shape protruding in a radial direction of the motor-generator, and are connected to each other by a first fastener extending parallel to the crankshaft, 2. The engine belt transmission device according to claim 1, wherein the second mounting portion and the accessory mounting portion are formed in a boss shape extending in a direction intersecting with the upper surface of the oil pan, and are interconnected by a second fastener passing through the second mounting portion and the accessory mounting portion.

3. an idler pulley disposed in a third belt span between the first pulley and the second pulley and pressing an outer peripheral surface of the belt; 3. The engine belt transmission device according to claim 2, wherein the idler pulley is attached to the second attachment portion.

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