JPH0472431A - Gear rattling sound preventing device for engine with manual transmission - Google Patents

Abstract

PURPOSE:To restrict gear rattling sound generated in the idling state at neutral position of a transmission below a specified level to reduce noise by increasingly controlling the idling engine speed. CONSTITUTION:Under the idling state at neutral position of a manual transmission, it is judged whether the operating condition depending on the engine speed, load, etc. falls in an operating region set by a noise region setting means or not, by a region judging means. further, when the operating condition does not fall in the noise region, that is, striking sound exceeds a specified level, the idling engine speed is increased by an idling engine speed-increase control means. In this case, since the direction of increasing the idling engine speed is the direction of restricting the change of rotation, the operating condition deviates from the noise region when the idling engine speed is increased to some extent.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a device for suppressing rattling noise of gears occurring in a neutral position of a manual transmission or an engine connected to an output shaft. .

<Prior Art> Generally, in an electronically controlled fuel injection type engine, a target rotation speed is set during idle, and the idle rotation speed is controlled to match the target rotation speed.

In that case, the target rotational speed is basically set according to the water temperature, and a method is generally used in which correction is made for load fluctuations caused by ON/OFF of an air conditioner or the like.

<Problem to be solved by the invention> By the way, in engines with manual transmissions, if the idle speed in the neutral position is low, the rotational fluctuations with each cylinder explosion will become large and the transmission gears will make a rattling sound (rattling noise). ) occurs.

In the idle rotation speed control device, the target rotation speed is set regardless of the gear rattling noise, so when the rotation speed is low and the load is high, the rattling noise may be generated due to rotational fluctuations. there were.

In response to this, conventional methods have been proposed to avoid the rattling noise by increasing the torsional characteristics of the clutch and the rigidity of the spring, but this method has limitations in terms of variation and processing accuracy. (Reference: Automotive Technology page 349
Society of Automotive Engineers of Japan, Sakai et al., Analysis and improvement of the rattling phenomenon of gears in manual transmissions [812B55] (1
981) ).

The present invention was made in view of such conventional problems, and an object of the present invention is to prevent gear rattling noise by controlling the idle rotation speed.

<Means for Solving the Problem> Therefore, as shown in FIG. 1, the present invention provides a method for solving the problem in which, in an engine connected to a manual transmission or a pressure shaft, the rattling sound of the gears in the neutral position of the transmission exceeds a predetermined level. a noise region setting means for setting an operating region of the engine; a means for detecting the operating state of the engine; and a means for detecting the operating state of the engine, the operating state of the engine detected at the neutral position of the transmission being included in the operating region set by the noise region setting means. an idle speed increase control means for increasing the engine speed until the engine speed falls outside of the operating range when the range determining means determines that the engine is within the operating range; It is composed of .

<Operation> In the idle state of the manual transmission in the neutral position, the region determining means determines whether the operating state is determined by the engine speed and load, etc., or whether it is included in the operating region set by the noise region setting means. be done.

When the rattling noise is not included in the noise region, that is, when the rattling noise exceeds a predetermined level, when the idle rotation speed is increased by the idle rotation speed increase control means, the direction of increase is in the direction of suppressing rotation fluctuation. Therefore, if the noise level is increased to a certain point, it will be out of the noise range.

In this way, gear rattling noise can be suppressed to less than a predetermined level throughout the entire idle state, and the riding feeling can be improved.

<Example> Embodiments of the present invention will be described below based on the drawings.

In FIG. 2 showing the configuration of one embodiment, an idle control valve 5 is interposed in an auxiliary air passage 4 that bypasses and connects the upstream and downstream sides of an intake throttle valve 3 installed in an intake passage 2 of an engine 1. The idle speed is controlled by controlling the opening degree of the idle control valve 5 according to the operating conditions of the engine.

The opening control amount of the idle control valve 5 is set as follows. That is, in order to suppress gear rattling noise to below a predetermined level, the method according to the present invention experimentally detects the level of the gear rattling noise that occurs while the transmission is idling in the neutral position, and adjusts the level to a predetermined level. The engine operating range (hereinafter referred to as the noise range; see FIG. 4) is set as described above. Specifically, the lower limit value of the engine load (for example, basic fuel injection amount T, intake pressure, etc.) with respect to the engine speed, or conversely the upper limit value of the engine speed with respect to the engine load, is assigned to a table map in the ROM. Then, it is determined whether or not the current engine operating state is included in the above-mentioned noise range, and if it is included, the idle speed is controlled to be increased.

In addition, while suppressing the rattling noise of the gear, so-called idle rotation speed feedback control is executed in parallel to bring the rotation speed closer to the target rotation speed similar to the conventional one.

Specifically, when the actual rotation speed is determined to be larger than the target rotation speed, before performing control to lower the rotation speed, it is determined whether or not it is included in the noise area. Control is performed to further increase the idle speed until it goes out of the range.

In other words, the signal from the idle switch 6 is turned off when the intake throttle valve 3 is in the idle position of 0N, the signal from the neutral switch 7 is turned on when the transmission is in the neutral position, and the signal from the clutch switch 8 is turned on when the clutch is connected. signal, cooling water temperature detected by water temperature sensor 9, engine speed detected by crank angle sensor 10, air conditioner switch 11
The control unit 13 determines the operating state of the engine based on the ON and OFF signals from the engine, the voltage signal of the battery 12, etc., and determines the valve opening duty (pulse The idle rotation speed is controlled by changing the opening control amount (which corresponds to the opening control amount).

In addition, on the upstream side of the intake throttle valve 3 in the intake passage 2,
An air flow meter 14 for detecting the intake air flow rate is provided, and further upstream thereof, an air cleaner 15 is provided.

Idle rotation speed control by the control unit 13 will be explained below with reference to the flowchart of FIG. 3.

In step 1 (denoted as S in the figure), the various sensors,
Input detection signals from switches.

In step 2, the basic control amount ISC, based on the water temperature T,
, various correction amounts ISC, such as air conditioner correction, as necessary.
Then, the control amount ISC is set by correcting the correction amount ISCvb according to the battery voltage.

In step 3, it is determined whether the operating conditions are such that the feedback control (ISC) is performed to make the idle speed match the target speed (for example, the conditions include that the idle switch 6 is ON).

When it is determined in step 3 that the operating conditions are such that feedback control is to be performed, the process proceeds to step 4, where the target rotational speed N is set by searching or calculating from the water temperature TV.

In step 5, the magnitude relationship between the engine rotation speed N detected based on the signal from the crank angle sensor 10 and the target rotation speed N8 is compared.

Then, when it is determined that N<NS, step 6
Proceed to , increase the idle speed to reach the target speed N,
To match the current ISC, a value obtained by adding the feedback correction amount ISC, , is updated and set as a new ISC.

Further, when it is determined in step 5 that N≧N5, the process proceeds to step 7, and a determination is made as to the operating conditions that cause the gear rattling noise. That is, idle switch 6° neutral switch 14. It is determined whether all clutch switches 15 are turned on. Further, if it is determined in step 3 that the idle rotation speed feedback control condition is not met, the process also proceeds to step 7.

If the judgment in step 7 is YES and the operating conditions are such that a gear rattling sound is generated, the process proceeds to step 8, and a rattling sound is detected from the table map assigned to the RAM for the current engine speed N. When the engine load exceeds a predetermined level, the lower limit value Tpa of the basic fuel injection amount T is searched.

In step 9, the basic fuel injection amount T determined in a separate routine is compared with the lower limit value TPO retrieved in step 8.

When it is determined that T, ≧ r pc, that is, when it is determined that it is included in the noise region, the process proceeds to step 10 to increase the idle rotation speed, and the ISC is increased by a predetermined amount ISC. Set update settings.

When it is determined that TP is less than T'PG, that is, when it is determined that the noise region is out of the noise range, the process proceeds to step 11, and it is determined again whether or not the idle rotation speed feedback control condition is met.

If it is determined that the idle rotation speed feedback control condition is met, the process proceeds to step 12, where the idle rotation speed is reduced to the target rotation speed N based on the determination that N≧Ns in step 5.

The value obtained by subtracting the feedback correction amount ■5C1b from the current ISC is updated and set as a new ISC in order to match the current ISC.

In this way, if the setting is updated in either step 6 or 10.12, or if it is determined in step 11 that the condition is not the idle rotation speed feedback control condition, the idle control valve 5 is opened as set in step 2. degree control amount T
SC is output in step 13, and the idle control valve 5 is controlled to an opening degree corresponding to the set amount ISC in accordance with the output signal.

With such a configuration, when the transmission is idling in the neutral position, if the gear rattle noise enters a noise range exceeding a predetermined level due to an increase in load (see Figure 4) or a decrease in rotational speed, the target rotation To increase the idle rotation speed to take it out of the noise range regardless of the idle rotation speed feedback control according to the engine speed, and to suppress gear rattling noise below a predetermined level, thereby improving the riding feeling. I can do it.

The present invention also includes an idle switch 6 for detecting the idle state, a crank angle sensor 10 for detecting the engine speed N, and an air flow meter 14 for detecting the intake air flow rate Q used to calculate the basic fuel injection amount T. constitutes an operating state detection means in which the lower limit value T of the basic fuel injection amount T
The ROM in which PO is assigned to the table map constitutes a noise area setting means, the function of step 7.89 in FIG. It constitutes a rotation speed increase control means.

In addition, as another example, the setting of the noise region where the rattling sound of the gear is at a predetermined level or higher is assigned to the table map as the upper limit value of the engine rotation speed NG for the engine load (basic fuel injection amount T). In this case, instead of step 8 in FIG. 3, the upper limit value N6 of the engine rotation speed for the currently detected load T is searched from the table map, and then the detected engine rotation speed N and the upper limit value are searched instead of step 9. Compare with the value NG, and if N>NG, step 11
If N≦N6, the process proceeds to step 10, where the idle speed is increased.

<Effects of the Invention> As explained above, according to the present invention, the rattling sound of the gears that occurs when the transmission is idle in the neutral position can be reduced to below a predetermined level over the entire idle range by increasing the idle rotation speed. It is possible to reduce noise, significantly improve riding comfort, and give the vehicle a luxurious feel.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a diagram showing the system configuration of an embodiment of the present invention, FIG. 3 is a flowchart showing the idle speed control routine of the same embodiment, and FIG. 4 FIG. 2 is a diagram showing a noise region set in the same embodiment. 1... Engine 5... Idle control valve 69
．． . Idle switch 10...Crank angle sensor 13
... Control unit) 14 ... Air flow meter patent applicant Nissan Motor Co., Ltd. agent Fujio Sasashima Figure 1 Figure 47 --- Large

Claims (1)

[Claims] In an engine in which a manual transmission is connected to an output shaft, a noise region setting means sets an engine operating region in which rattling noise of gears in a neutral position of the transmission is equal to or higher than a predetermined level; and an operating state for detecting the operating state of the engine. a detection means, a region determination means for determining whether or not the operating state of the engine detected at the neutral position of the transmission is included in the operation region set by the noise region setting means; An idle speed increase control means for increasing the engine speed until the engine speed falls outside the range when it is determined that the engine speed is within the range;
A gear rattling noise prevention device for an engine with a manual transmission, characterized by comprising: