JPH04276139A - Auxiliaries driving device for engine - Google Patents

Abstract

PURPOSE:To reduce the bending vibration of a crankshaft, and engaging noise by preventing angular speed change and torsional vibration from being transmitted to auxiliaries. CONSTITUTION:A power take-out gear 23 installed on a web 20 adjacent to the inside of the rearest journal 28 in a crankshaft 2 is formed out of a mounted part 25 which is pressed into the crankshaft 2, an outside-peripheral box part 27, and a rubber 26 provided between them, by which the torsional vibration of the crankshaft 2 is reduced and which functions as a damper which prevents angular speed change and torsional vibration from being transmitted to the auxiliaries. The rotational ratio of the auxiliaries driving shaft 10 is set so as to cancel the torsional vibration utilizing a sudden change in an oil pump 14 connected to the auxiliaries driving shaft 10.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine accessory drive system.

0002

[Prior Art] Auxiliary equipment for automobile engines, etc., is relatively compact and has a small load, such as oil pumps for lubrication or water pumps, and is placed at the front end of the engine, etc., and is connected directly to the crankshaft or In some cases, it is driven by a gear combination, but in general, the auxiliary equipment, including heavy-load auxiliary equipment such as the air conditioner compressor and alternator, is placed on the side near the front or rear end of the engine, and the crankshaft Usually, a belt or chain is passed from the end of the motor to drive the motor. For example, in the system described in West German Patent No. 3838073, the engine and transmission are installed in parallel to the vehicle body with a rear slant (tilt), and the rear slant compensates for the space created in front. The auxiliary machines are arranged so that these auxiliary machines are driven by a belt running from the crankshaft.

By the way, in conventional engines, including the engine described in the above-mentioned West German patent specification, the flywheel is generally fixed to the clutch connecting side (rear side) end of the crankshaft, while the A pulley for driving an auxiliary machine is fixed to the other end (front side) via a belt. Furthermore, in such engines, torsional vibrations of the crankshaft have been conventionally reduced by incorporating a damper mechanism into the front pulley. That is, since the front pulley itself has a considerable weight, an elastic body such as rubber is interposed between the central shaft portion and the outer peripheral mass portion to function as a damper against torsional vibration. In this case, the torsional vibration of the crankshaft has a node at the end on the flywheel side that is connected to the transmission via the clutch, and the amplitude is maximum on the front side. Torsional vibration can be effectively reduced by using the pulley as a damper.

0004

[Problem to be Solved by the Invention] As mentioned above, the damper mechanism provided on the pulley at the front end of the crankshaft is effective against torsional vibration, but it is not effective against bending vibration. did not become. In particular, at the rear end near the flywheel fixed part, bending occurs between the journals due to the excitation force of the rearmost cylinder, and this energy excites the flywheel, causing a large bend. As a result, vibration noise is generated, but if a damper is provided at the front end farthest from the part where bending is most problematic, it cannot be expected to be very effective against bending. Moreover, the damper at the front end of the crankshaft has a greater effect as it weighs more, but at the same time, the natural frequency decreases, which narrows the area where vibration can be reduced due to opposite phases, and conversely, the area where vibrations can be reduced due to the same phase. This can lead to negative effects such as a decrease in torsional rigidity.

[0005] Additionally, since the front or rear end of an engine's oil pan generally has a relatively dead space, there is a desire to utilize this space to realize a compact arrangement of auxiliary equipment. , the inventor has
For example, if the engine and transmission are arranged in parallel,
By providing an integrated oil pan at the bottom of the engine and transmission, we are able to secure a sufficient installation area for the oil pan, which allows us to secure the volume of the oil pan while also installing auxiliary equipment and drive mechanisms that place a relatively small load on the oil pan. I'm thinking of setting up a . In this case, the auxiliary drive mechanism includes, for example, an auxiliary drive shaft that passes through the oil pan, a power take-off gear on the rearmost web of the crankshaft, and a power take-off gear connected to the transmission side gear and chain mechanism. A structure in which the engine's angular velocity fluctuations are transmitted to the auxiliary equipment drive shaft via a motor, etc. can be considered, but in that case, the engine's angular velocity fluctuations would be transmitted to the auxiliary equipment, and the driving force would be extracted from a position that is relatively less susceptible to the effects of torsion. However, torsional vibrations are still transmitted, and abnormal noises such as meshing noises are generated in the gear connection section.

The invention of this application has been made in view of the above-mentioned problems, and its object is to reduce the bending vibration of the crankshaft.

[0007] The invention of this application also prevents transmission of angular velocity fluctuations to the auxiliary equipment when power is transmitted to the auxiliary equipment drive shaft via the power take-off portion provided on the crankshaft, and
The purpose is to prevent transmission of torsional vibration and reduce abnormal noise such as meshing noise.

[0008]

[Means for Solving the Problems] The invention of this application provides an engine accessory drive device that extracts power for driving accessories from a crankshaft supported by a block of an engine body. A power take-off part for driving an accessory is provided adjacent to the inner side of the rearmost journal at the end on the wheel support side, so that the bending of the crankshaft is prevented by the action of the accessory drive mechanism connected to the power take-off part. Vibration and angular velocity fluctuations can be reduced.

[0009] Furthermore, in the invention of the present application, in the above structure, the power take-off part is constituted by a gear, and the attachment part and the outer periphery of either the gear of the power take-off part or the transmission gear meshed with the gear. An elastic body is interposed between the crankshaft and the mass, thereby further reducing the bending vibration and torsional vibration of the crankshaft, and also preventing the occurrence of meshing noise of the gear joint.

Furthermore, in the above configuration, an auxiliary machine having periodic load fluctuations, such as an oil pump, can be driven and connected to the power extraction section, thereby converting load fluctuations such as discharge fluctuations into torsional vibrations in the opposite phase. By matching them together, the effect of reducing meshing noise can be enhanced.

[0011]

[Operation] A power take-off part for driving the auxiliary equipment is provided adjacent to the inner side of the rearmost journal at the end of the crankshaft on the flywheel support side, so that the auxiliary equipment drive mechanism is connected to the power take-off part. The auxiliary equipment driven thereby provides resistance to bending vibrations and angular velocity fluctuations of the crankshaft, thereby reducing the bending vibrations and angular velocity fluctuations.

[0012] Furthermore, since the power take-off section is constituted by a gear, and an elastic body is provided between the attachment section and the outer peripheral mass section of this gear and one of the transmission side gears, a damper effect is produced. Bending vibrations and torsional vibrations of the crankshaft are further reduced, and generation of meshing noise and the like at the gear joints is prevented.

Furthermore, by drivingly connecting an oil pump or the like to the power extraction section, it is possible to cancel torsional vibration by utilizing load fluctuations such as discharge fluctuations, thereby increasing the effect of reducing meshing noise. Can be done.

[0014]

Embodiments Hereinafter, embodiments of the invention of this application will be described based on the drawings.

FIG. 1 is a partial sectional view of an engine according to an embodiment of the invention of this application, viewed from the front side (front of the vehicle body), and FIG.
is a partial sectional view of the same engine as seen from the front end side (left side of the vehicle body).

[0016] The engine 1 of this embodiment is an in-line four-cylinder engine, and is mounted in the front part of the vehicle body with the crankshaft 2 oriented horizontally in the vehicle width direction, with a rear slant. A transmission 3 is arranged in parallel on the side of the engine 1 and located at the rear when viewed from the front of the vehicle, and an oil pan 4 of an integrated structure is arranged below the engine 1 and the transmission 3. . Further, a surge tank 6 is provided on the front side of the engine 1 at a position close to the lower block 5 that constitutes the main body skirt portion, and an intake pipe 7 that communicates the surge tank 6 with the combustion chamber of each cylinder is arranged upwardly. It extends in a curved manner and is connected to the cylinder head 8.

[0017] The oil pan 4 is arranged so that the engine 1 and the transmission 3 are slanted to the rear.
The lower block 5 is formed to fill a generally triangular space in a side view that is formed below the engine 1, and in the longitudinal direction of the engine 1, from a position close to the clutch housing 9, the lower block
It is provided in a range up to a position retracted a predetermined distance from the front end of.

An auxiliary drive shaft 10 is provided in the oil pan 4 so as to pass through a portion thereof on the engine 1 side in a direction parallel to the crankshaft 2. On the rear end side of the engine 1, below the clutch housing 9, an oil pump (hereinafter referred to as A
It's called a T oil pump. ) 11 is disposed, and a power steering pump 12 is disposed outside thereof, and these AT oil pump 11 and power steering pump 12 are connected in series to the end of the accessory drive shaft 10. Also oil pan 4
On the front end side, a water pump 13 is disposed in a recess formed on the side of the oil pan 4 below the lower block 5.
This is connected to the end of the accessory drive shaft 10. Also,
An oil pump (hereinafter simply referred to as oil pump) 14 for lubricating the engine is disposed inside the side wall of the oil pan on the side to which the water pump 13 is connected, and is connected to the auxiliary drive shaft 10 .

A partition wall 15 is formed in the shape of a box in the oil pan 4 at a position close to the side wall away from the oil pump 14 . The auxiliary drive shaft 10 passes through this partition wall 15, and a driven side sprocket 16 is provided at a position surrounded by the box-shaped partition wall 15. Further, in the oil pan 4, an extending portion 15a of the partition wall 15 is located at a position near the rear end of the engine on the mission 3 side of the partition wall 15.
is provided, and the shaft portion 1 of the idle gear 17 is provided on its upper end surface.
A support member 19 that rotatably supports 8 is fixed. The idle gear 17 is arranged at a position facing the No. 8 web 20 on the rear end side of the crankshaft, and a driving side sprocket 21 is fixed to the tip of the shaft portion 18 at a position facing the driven side sprocket 16. There is.

The two sprockets 16 and 21 on the driven side and the driving side are connected by a chain 22. In addition, the above No. 8 web 2 is attached to the crankshaft 2 of the engine 1.
A power take-off gear 23 is provided at the 0 portion, and the gear 23 and the idle gear 17 are engaged with each other.

With this configuration, the power taken out from the power take-off gear 23 is transferred to the idle gear 1.
7, and further transmitted to the accessory drive shaft 10 via the drive sprocket 21, chain 22, and driven sprocket 16. Then, the AT oil pump 11, power steering pump 12, water pump 13, and oil pump 14 connected to the auxiliary drive shaft 10 are driven. Further, an oil filter 24 is attached to the front end side wall of the oil pan 4 from the outside. In the figure, 24a is a sub-gallery that communicates the discharge port of the oil pump 14 with the suction port of the oil filter 24.

The power take-off gear 23 has a mounting portion 25 having an L-shaped cross section press-fitted into the No. 8 web 20 of the crankshaft 2, and a mass portion 27 having gear teeth on the outer periphery attached to the mounting portion 25 via a rubber 26. The rubber 26 is interposed between the mounting portion 25 and the mass portion 27 in the radial and axial directions, so that it also functions as a damper against bending and twisting of the crankshaft 2.

The power extraction gear 23 is attached to the No. 8 web 20 as described above, and is adjacent to the inside of the rearmost journal 28 of the crankshaft 2. The rear end of the crankshaft 2 is provided with the rearmost journal 28.
A flywheel fixing portion 29 provided adjacent to the outside of the
A flywheel 30 is fixed to. therefore,
The mounting position of the power take-off gear 23 is the position where the bending amplitude of the crankshaft 2 is the largest, and since the power take-off gear 23 functions as a damper at this position, bending vibrations are particularly efficiently reduced. Further, a pulley 32 is attached to the front end of the crankshaft 2 for belt driving an air conditioner compressor 31 and the like. The pulley 32 has a mounting portion 33 and a mass portion 34 having a belt groove on the outer periphery fixed to each other via a rubber 35, and constitutes a damper against torsional vibration. Torsional vibration of the crankshaft 2 is reduced by the dampers of both the front pulley 32 and the rear power extraction gear 23.

In addition, as described above, the power take-off gear 23
By forming a damper, angular velocity fluctuations transmitted to the auxiliary equipment side via the idle gear 17 are reduced, torsional vibrations are reduced, and differences in the meshing portion between the power take-off gear 23 and the idle gear 17 are reduced. Sound generation is suppressed.

Furthermore, in this embodiment, since the oil pump 14 is connected to the auxiliary drive shaft 10 as described above, the angular velocity fluctuations and torsional vibrations of the crankshaft 2 can be more effectively suppressed by utilizing its discharge fluctuations. It is possible to reduce the That is, by appropriately setting the rotation ratio of the auxiliary drive shaft 10 to the rotation of the crankshaft 2 and matching the phase and order of the oil pump discharge pulsation with the opposite phase to that of the angular velocity fluctuation of the crankshaft 2, the order to be reduced can be adjusted. It is possible to cancel the vibration of

In the above embodiment, a damper is also provided on the front side of the crankshaft, but it is also possible to omit the damper on the front side.

Further, the damper provided on the rear power output gear may be a damper exclusively for bending, or a damper exclusively for torsion.

Further, in the above embodiment, the power take-off gear has a damper function, but if the main aim is to reduce meshing noise, the idle gear that meshes with the power take-off gear may have a damper function. Good too.

[0029]

[Effects of the Invention] Since the invention of this application is constructed as described above, it is possible to reduce the bending vibration of the crankshaft by using the auxiliary drive mechanism. By having one of the transmission gears on the auxiliary equipment function as a damper, it is possible to prevent the transmission of angular velocity fluctuations to the auxiliary equipment, as well as prevent the transmission of torsional vibration and reduce abnormal noise such as meshing noise. .

Furthermore, it is possible to cancel torsional vibration by utilizing the discharge fluctuation of the oil pump, and to more effectively reduce meshing noise and the like.

[Brief explanation of the drawing]

[Fig. 1] Partial cross-sectional view of an engine according to an embodiment of the invention of this application, seen from the front side (front of the vehicle body)

[Figure 2] Partial cross-sectional view of the engine seen from the front end side (left side of the vehicle body)

[Explanation of symbols]

1 Engine 2 Crankshaft 10 Auxiliary drive shaft 14 Oil pump 17 Idle gear (transmission side gear) 23 Power extraction gear 25 Mounting part 26 Rubber 27 Mass section 28 Last journal 29 Flywheel fixing part 30 Flywheel

Claims (3)

[Claims] 1. An accessory drive device for an engine configured to extract power for driving accessories from a crankshaft supported by a block of an engine main body, wherein the rearmost portion of the crankshaft at the end on the flywheel support side. An auxiliary equipment drive device for an engine, characterized in that a power extraction part for driving an auxiliary equipment is provided adjacent to the inside of a journal. 2. The power take-off portion is constituted by a gear, and an elastic body is interposed between the outer peripheral mass portion and the attachment portion of either the gear or the transmission gear meshed with the gear. engine auxiliary drive system. 3. The engine auxiliary drive system according to claim 1, wherein an auxiliary machine having periodic load fluctuations is drivingly connected to the power extraction section.