JPH01285625A - Auxiliary device disposing structure for engine - Google Patents

Abstract

PURPOSE:To reduce a ratio of a tensionless period on the slacking side of a belt by a method wherein, in a device having a plurality of auxiliary devices through a single belt by means of a crank pulley, the plurality of the auxiliary devices are arranged, in order, from the stretch side of the belt and in order of the intensity of a rotation inertia force. CONSTITUTION:A main auxiliary device drive belt 8 is run around the order of a crank pulley 3, mounted on a crank shaft 2 of an engine E, an air conditioner pulley 5, and an alternator pulley 7. Further, a second auxiliary drive belt 12 is run around in the order of the air conditioner pulley 5 and a power steering pulley 11. Namely, an air compressor 4 and an alternator 6 are disposed in the order of the intensity of a rotation inertia force from the tension side of the drive belt 8 responding to the rotation direction of the crank pulley 3. A power steering 10 is disposed on the air compressor 4 side, the rotation inertial force of which is higher than the other device, of the two devices 4 and 6, and the devices 4, 6, and 10 are driven through the drive force of the crank shaft 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine auxiliary equipment arrangement structure in which the engine auxiliary equipment is driven by a belt.

(Prior Art) Conventionally, in order to drive various engine auxiliary equipment such as an air conditioner compressor, an alternator for power generation, an oil pump for power steering, a water pump for cooling water, etc. using the driving force of the crankshaft of an engine,
An auxiliary drive belt such as a V-ribbed belt is stretched from the crank pulley to the pulley of each auxiliary machine to drive the drive.
(Refer to Publication No.-143045).

If the tension of the accessory drive belt is low, there will be a noise problem due to excessive slippage, and if the tension is high, there will be a problem that the durability of the accessory drive belt and various parts of the accessory will be reduced.

(Problem to be Solved by the Invention) However, with the recent increase in load on auxiliary equipment and increase in torque fluctuation due to engine combustion, belt noise caused by rotational fluctuations of the drive pulley has become a problem.

Therefore, even if the belt tension is the same, depending on the arrangement of the auxiliary machines, belt slip can be reduced and the generation of abnormal noise can be suppressed.

Abnormal noise in the auxiliary drive belt is likely to occur when the tension is low or when the load on the auxiliary equipment increases.Especially in automatic transmission types, the moment of inertia of the crankshaft is small, which promotes fluctuations in engine rotation due to fluid resistance. This tendency is significant because there are factors that cause In accessory drive belts, abnormal noise is known to occur due to radial slippage of the pulley and tangential slippage. Particularly in the case of V-ribbed belts, the radial slippage is small, and the abnormal noise is caused by a decrease in tension. Since it occurs only occasionally, it is thought to be caused by tangential slip.

In other words, when we measure the occurrence of abnormal belt noise with respect to engine rotational fluctuations and crank angle, as shown in Fig. This occurs at a timing after approximately 45" of combustion, in sync with engine rotational fluctuations. At the same time, the belt speed decreases and the t
It can be seen that a deviation from the 0 speed has occurred.

In view of the above circumstances, the present invention provides an engine auxiliary equipment arrangement structure that prevents abnormal noise by obtaining an appropriate arrangement of auxiliary equipment corresponding to the abnormal noise generation mechanism of the auxiliary equipment drive belt. The purpose is to provide the following.

(Means for Solving the Problems) In order to achieve the above object, the auxiliary equipment arrangement structure of the present invention has a structure in which a plurality of auxiliary equipments are driven by a crank pulley using one belt. The machines are arranged in descending order of rotational inertia, starting from the belt tension side.

(Function) In the engine auxiliary equipment arrangement structure as described above, when multiple auxiliary equipment are driven by the crank pulley, belt noise occurs when the belt loosens and the ratio of the tension-free period of the steel tension exceeds a predetermined value. Focusing on this, we arranged multiple auxiliary machines driven by the crank pulley in order of increasing rotational inertia, starting from the tension side, in order to reduce the no-tension period ratio, so that the belt tension was the same. This also minimizes the tension-free period on the slack side of the belt, allowing more auxiliary machinery to be driven while suppressing the occurrence of belt slip.

(Example) Hereinafter, each embodiment of the present invention will be described along with the drawings.

Embodiment 1 The auxiliary equipment arrangement structure of this example is shown in FIG. ) and the alternator pulley 7 (ALT pulley) of the alternator 6, and the main auxiliary drive belt 8 is connected to the power steering pulley 11 (P/S pulley) of the power steering pump 10 from the A/C pulley 5. A secondary auxiliary drive belt 12 is applied, and each auxiliary machine 4, 6, 10 is driven by the driving force of the crankshaft 2 of the engine E.

Then, the rotational inertia force (Kg-f' S 2/ca
The size of b) is: Air conditioner compressor...0.058 Alternator...0.03 Bawa steering bomb...O, OL5 water pump
...0.015, and the C/S boo 9-
The air conditioner compressor 4 and the alternator 6 are arranged in the order of increasing rotational inertia from the tension side of the main auxiliary drive belt 8 corresponding to the rotational direction of No. The power steering pump 10 is driven by the secondary auxiliary drive belt 12. Note that the rotational inertia force is determined by the rotational mass of the auxiliary machine and the rotation radius of the pulley, and as the pulley diameter changes, the magnitude of the rotational inertia force of the auxiliary machine changes.

In addition, each pulley 3 in the main auxiliary drive belt 8
．． 5. The inter-pulley belt lengths Ll to L3 of No. 7 are set so that Ll<Lz<
It is set to L3. Furthermore, the winding angles R1 and R2 of the belt 8 around the auxiliary equipment boos 9-5 and 7 are set to be larger on the ALT pulley 7 than on the A/C pulley 5, which has a larger rotational inertia of the auxiliary equipment. .

In the above structure, angular velocity fluctuations occur in the crankshaft 2 due to the combustion cycle caused by engine operation, and the driving force having the angular velocity fluctuations causes the auxiliary drive belt 8,
Each auxiliary machine 4.6° 10 is driven through the C/S pulley 3, but if the angular velocity fluctuation is large on the slack side, the difference between the angular velocity of the C/S pulley 3 and the velocity of the belt 8. 10 rotational inertia and the belt length between each pulley, which increases the slip rate and generates belt noise.
It varies depending on the belt rigidity, and the larger the rotational inertia force, the larger the angular velocity fluctuations, and the longer the distance between the shafts and the lower the belt rigidity, the larger the angular velocity fluctuations tend to be.

Regarding the above characteristics, by arranging an auxiliary machine with a large rotational inertia force from the tension side, the angular velocity fluctuation in the dynamic fluctuation in response to the rotational fluctuation of the C/S pulley 3 in the A/C pulley 5 is reduced. As a result, fluctuations in the loose copper tension T3 are also suppressed, and the period during which the loose copper tension T3 is in a tension-free state when the tensioned copper tension TI is at its maximum is shortened, which can lead to belt noise. This reduces the slip rate caused by the difference between the angular velocity of the pulley at No. 3 and the speed of the belt 8. For example, if an auxiliary machine with a large rotational inertia is placed lower in the order, the length of the tension side belt up to this auxiliary machine will become longer, the actual spring constant of the belt will decrease, the pulley rotational displacement will increase, and the tension will fluctuate. will increase. Furthermore, as the spring constant decreases, the natural frequency of the system approaches the excitation frequency of the C/S pulley 3, and tension fluctuations are amplified.

In addition, the auxiliary equipment driven by the secondary auxiliary equipment drive belt 12 is driven via the A/C pulley 5 closest to the C/S pulley 3, and the one with the smallest rotational inertia is arranged to prevent tension fluctuations. suppress. That is, the elasticity of the secondary auxiliary drive belt 12 increases the tension fluctuation, and therefore the drive pulley C
Displacement is suppressed by driving via the A/C pulley 5, which is closest to the /S pulley 3 and has small angular velocity fluctuations, and by secondary driving the power steering pump 10, which has a smaller rotational inertia than the others.

In addition, even when excluding the secondary drive in the above example and driving multiple auxiliary machines with one main auxiliary drive belt 8,
As above, arrange the auxiliary equipment with the largest rotational inertia from the tension side, and set the belt length between each pulley to increase sequentially from the tension side to the slack side. The angle is set so that it increases in order from the tension side.

Embodiment 2 The auxiliary equipment arrangement structure of this example is shown in FIG. The main auxiliary drive belt 8 is applied to the /S pulley 11, and the C/S pulley 3
A secondary auxiliary drive belt 12 is applied to the ALT pulley 7 of the alternator 6, and each auxiliary machine 4, 6, 10 is driven by the driving force of the crankshaft 2 of the engine E.

Also in this example, the air conditioner compressor 4,
A power steering pump 10 is provided, and the alternator 6, which has a small rotational inertia, is driven directly from the C/S pulley 3 by a secondary auxiliary drive belt 12.

In addition, each pulley 3 in the main auxiliary drive belt 8
．． The inter-pulley belt lengths L5 to L3 in 5.11 are set to increase successively from the tension side to the slack side, as in the previous example. Furthermore, the angle R1 to R2 of the winding of the belt 8 around the accessory pulley 5.11 is determined by the A/C where the rotational inertia of the accessory is large.
The P/S pulley 11 is set to be larger than the pulley 5.

In this example, the C/S pulley 3 directly drives the alternator 6 as a secondary drive, so that the displacement is further reduced compared to the previous example.

It should be noted that the difference from the previous example is the degree of freedom in arranging auxiliary equipment corresponding to the space around the engine.

Embodiment 3 The auxiliary equipment arrangement structure of this example is shown in FIG. The main auxiliary equipment drive belt 8 is applied to the W/P pulley 15, and the secondary auxiliary equipment is connected from the C/S pulley 3 to the ALT pulley 7 of the alternator 6 and the P/S pulley 11 of the power steering pump 10. Hook the drive belt 12 onto the crankshaft 2 of the engine E.
Each of the auxiliary machines 4, 6, 10.14 is driven by the driving force.

Also in this example, the air conditioner compressor 4,
A water pump 14 is disposed, and similarly, an alternator 6 and a power steering pump 10 are disposed in descending order of rotational inertia from the tension side of the secondary auxiliary drive belt 12.

In addition, the main and secondary auxiliary drive belts 8, 1
Similarly, the belt lengths 1 to L6 between the pulleys in No. 2 are set to increase successively from the tension side to the slack side. Further, the angles R1 to R4 of the belt wrapping around the auxiliary pulley 5°15.7.10 are set to increase in order from the tension side.

Embodiment 4 The auxiliary equipment arrangement structure of this example is shown in FIG. The main accessory drive belt 8 is applied to the W/P pulley 15 of the water pump 14, and the secondary accessory drive belt is connected from the A/C pulley 5 to the P/S pulley 11 of the power steering pump 10. 12, and each auxiliary machine 4.6, 10.14 is driven by the driving force of the crankshaft 2 of the engine E. In addition, A/C pulley 5 and ALT pulley 7
An idler 16° 17 is disposed between the C/S pulley 3 and the W/P pulley 15.

Also in this example, the air conditioner compressor 4,
An alternator 6 and a water pump 14 are installed, and further,
From the A/C pulley 5 to the secondary accessory drive belt 12
Power steering pump with small rotational inertia 1
It is configured to drive 0.

Furthermore, the belt length between each pulley in the main auxiliary drive belt 8 is L 1 to L a (L 2 = L 2
A+L2B, L, -L4A+L4B) are similarly set to increase in length from the tight side to the loose side.

Furthermore, auxiliary equipment pulley 5. 7. The belt winding angle R1-R3 at 15 is set to increase in order from the tension side due to the installation of idlers 16 and 17.

Embodiment 5 The auxiliary equipment arrangement structure of this example is shown in FIG. One auxiliary drive belt 8 is applied to the P/S pulley 11 of the power steering pump 10, and each auxiliary machine 4, 6, 10 is driven by the driving force of the crankshaft 2 of the engine E. Additionally, an idler = 18 is provided between the ALT pulley 7 and the P/S pulley 11.
has been set up.

Also in this example, the air conditioner compressor 4, alternator 6, and power steering pump 10 are driven in descending order of rotational inertia from the tension side of the accessory drive belt 8 corresponding to the rotational direction of the C/S pulley 3. It has been established.

Furthermore, the lengths of the belts between the pulleys (1 to Lact, 3-L3A+L3B) in the accessory drive belt 8 are similarly set to increase in length from the tension side to the slack side. Furthermore, auxiliary equipment pulley 5. 7. The angle R1-R3 of the belt winding angle 11 is set to increase in order from the tension side due to the installation of the idler 18.

In each of the above embodiments, the auxiliary equipment is arranged to minimize fluctuations in belt tension at each part, and the no-tension period on the slack side of the belt is set to the maximum even if the tension is the same. This allows for efficient driving while suppressing the occurrence of belt slip and preventing abnormal noise.

The simulation noise evaluation results of the abnormal noise generation state of the auxiliary equipment arrangement structure of the above embodiment are shown in FIG. 6 together with a comparative example.

In this abnormal noise evaluation, an evaluation score of 7 is a high evaluation in which no abnormal noise is generated, and the evaluation score decreases as the occurrence of abnormal noise increases. Auxiliary equipment arrangement structure example ■ ~ ■ Example ■
, ■ and ■ correspond to examples of the present invention. In example ■, the power steering pump, which has a smaller rotational inertia than the air conditioner compressor, is located on the tension side, and in example ■, the power steering pumps are arranged in descending order of rotational inertia from the tension side.
The abnormal noise is lower than in Example ■. In this example (2), the secondary drive is not performed via the pulley on the tension side, so in example (2), where this is performed via the A/C pulley as in Example 1 (Fig. 1), the tension The reduction in fluctuation further reduces the occurrence of abnormal noises.

On the other hand, Example (2) has an arrangement structure corresponding to the second embodiment (FIG. 2), in which the secondary drive is directly performed by the C/S pulley, and almost no abnormal noise is generated. In example ■, the arrangement of the auxiliary equipment in example ■ has been changed so that the one with smaller rotational inertia is located on the tension side.
Along with this, the occurrence of abnormal noises is increasing.

Incidentally, FIG. 7 shows the results of Apl determination of the relationship between the generation of abnormal noise and the variation in belt tension as described above. This is, for example, by detecting fluctuations in the tension side tension TI, intermediate tension T2, and slack side tension T3 between the pulleys of the main auxiliary drive belt in Example ① above. Figure 7B shows the fluctuations in the tensions T1 to T3 between the booms (actual tension/set tension), and Figure 7B shows the sound pressure waveform (abnormal noise level) in the above state, as well as the tension T1 on the tight side and the tension T1 on the loose side. , the friction coefficient μ required for a part of the C/S pulley is shown.

The tension on the tight side T1, where the belt load is highest, has a large fluctuation, and the tension on the loose side T3 has an antiphase pattern with respect to the tension on the tight side TI, from the vicinity where the tension on the tight side becomes the maximum tension to zero ( (no tension). In this example, an abnormal noise is generated, and the tension side tension T5 collapses and decreases near the maximum tension that should have increased as shown by the broken line and hatching.
The tension-free period when the slack side tension T3 becomes zero becomes longer,
This increases the slip rate and causes belt noise.

The slack side tension T, which is the cause of this belt noise, is
The fluctuation of tension side tension “r, , T,” which affects 3.
This changes depending on the arrangement of the auxiliary equipment, and by arranging the auxiliary equipment in a state where tension fluctuations are small as described above, the no-tension period of the slack side tension T3 is reduced and the occurrence of abnormal noise is prevented. It is something that can be done.

In addition, instead of determining the abnormal noise generation state by measuring the tension fluctuations as described above, it is possible to calculate the abnormal noise generation state by preliminarily calculating all the tension fluctuations as described above through simulation calculation. The preferred arrangement structure of the auxiliary equipment can be determined by The details of this simulation calculation are omitted, but for static tension calculation of belt tension,
The auxiliary drive system is determined by adding a dynamic response calculation based on a vibration model, with the belt as the spring and the rotational moment of inertia of the auxiliary equipment as the mass.

The calculation flow for the entire simulation described above will be explained along the flowchart of FIG. 9. In step S1, various data (layout, auxiliary equipment load, moment of inertia, belt spring constant, crankshaft angular velocity fluctuation, etc.) are input, and in step S2 static tension is calculated, and in steps 53 to S5
Perform dynamic tension calculations. Changing the auxiliary equipment arrangement structure involves changing the input data in step S1 above,
For example, if an auxiliary machine with a large rotational inertia is disposed on the slack side, the belt spring constant will decrease.

In the dynamic tension calculation described above, modal analysis is performed in step S3, each boob speed is calculated in step S4, and fluctuating tension calculation is further performed in step S5.

In step S6, a composite tension calculation is performed based on the result of the static tension calculation and the result of the dynamic tension calculation, and in step S7, the no-tension period ratio of the loosened steel tension is calculated, and the slip rate is determined in step S8 accordingly. However, it also performs abnormal noise determination. The above-mentioned slip rate and abnormal noise are determined from an experimental formula of the percentage of loose copper tension of zero, slip rate, sound pressure level, and sensory evaluation score.

(Effects of the Invention) According to the present invention as described above, when a plurality of auxiliary machines are driven by a crank pulley with one belt, the plurality of auxiliary machines driven by the crank pulley are sequentially driven from the tension side of the belt. By arranging the belts in descending order of rotational inertia, even if the belt tension is the same, the percentage of no-tension period on the belt slack side is minimized, and more auxiliary equipment can be driven while suppressing belt slippage. It is something that can be done.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the auxiliary equipment arrangement structure of an engine in a first embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the same in a second embodiment, and FIG. 3 is a third embodiment. FIG. 4 is the same schematic diagram of the fourth embodiment, FIG. 5 is the same schematic diagram of the fifth embodiment, and FIG. 6 is the abnormal noise generation state of the auxiliary equipment arrangement structure. Fig. 7 is an 811 constant diagram showing the tension fluctuation during operation and the sound pressure waveform of the corresponding abnormal noise, and Fig. 8 is the circumferential speed fluctuation and abnormal noise generation. A graph showing the timing, FIG. 9 is a flowchart showing the flow of simulation calculation. E...Engine, 2...Crankshaft,
3...Crank pulley, 4, 6, 10.14
...Auxiliary machine, 5゜7.11.15...Auxiliary machine pulley, 8,12...Group/Auxiliary machine drive belt. Figure 2 Figure 3 Figure 6 Figure 1 (P1 numbered section Figure 7 (8) (B)

Claims (1)

[Claims] (1) In an engine in which multiple auxiliary machines are driven by a crank pulley using a single belt, the multiple auxiliary machines driven by the crank pulley are arranged in order from the tension side of the belt and in descending order of rotational inertia. An engine auxiliary equipment arrangement structure characterized by the following.