JP2002180934A - Injector noise detector - Google Patents

Abstract

(57) [Summary] [Object] To detect an injector noise of an engine with high accuracy. A lift signal of a valve element B for opening and closing an injection hole of an injector is differentiated to detect a valve element speed (S101, S101).
102), the square value of the minimum speed value vi is integrated (S10).
3) Multiply the integrated value V by the weight m of the valve body B to calculate the total operating energy E when the valve is closed (S104).
The injector noise P is calculated by multiplying the total E of the operating energy by the transfer coefficient H (S105), and the calculated value P is output (S106).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting a noise level of an injector (fuel injection valve) used for a direct injection gasoline engine or a direct injection diesel engine applied to an automobile or the like.

[0002]

2. Description of the Related Art Direct-injection gasoline engines and direct-injection diesel engines have been in the spotlight due to increasing interest in improving fuel efficiency of automobiles in response to environmental problems in recent years. Due to the effect of the hard mount of the injector, the injector noise at the time of low engine rotation such as idling has become a problem. Also, with the introduction of the common rail fuel injection system, the combustion excitation force of direct injection diesel engines has been greatly reduced compared to the past, and as a result, injector noise has become relatively noticeable. ing. As described above, in these direct injection engines, the reduction of injector noise is one of the important issues for improving the marketability, and an injector noise detection technique as a means for solving the problem is attracting attention.

[0003] As one method for simply detecting the injector noise, for example, the '00 FISITAF2000H1
Focusing on the fact that the noise power of the injector is proportional to the rail pressure (fuel pressure in the common rail) as shown at 85 ', the injector noise is estimated by multiplying the rail pressure by the transfer coefficient obtained by multiple regression analysis. The technique is known in the art.

[0004]

The detection of the injector noise by such a method has been effective under the condition that a single injection is performed at a certain constant engine speed. However, in actual engines, especially common rail direct injection diesel engines, pilot injection and post injection are often performed before and after main injection due to requirements such as emission and noise.In this case, the injector noise is reduced even under the same rail pressure. Increase significantly. Also, when the engine speed is high even under the same rail pressure, the injector noise also increases due to an increase in the number of injector operations per unit time. In this way, changes in injector noise due to the presence or absence of sub-injection and differences in engine rotation cannot be grasped solely from rail pressure information, and multiple transmission coefficients are required to deal with those changes. Thus, there is a problem that the calculation becomes complicated or a huge data capacity is required.

The present invention has been made in view of such conventional problems, and is simple and highly accurate irrespective of changes in operating conditions such as presence or absence of sub-injection and changes in engine speed. It is an object to provide a device for detecting injector noise.

[0006]

According to the present invention, a moving speed detecting means for detecting a moving speed of a movable portion of an injector, and a movable portion having a stopper based on the detected speed signal are provided. And a noise level estimating means for estimating a noise level of the injector based on the detected seating speed.

According to the first aspect of the present invention, since the noise level is estimated by detecting the seating speed based on the moving speed of the movable part, the injector noise is estimated with higher accuracy than the estimation based on the fuel pressure or the like. it can. In the invention according to claim 2, the noise level estimating means integrates an absolute value or a square value of the movable portion sitting speed detected during a predetermined time, and adds the calculated speed absolute value or an integrated value of the square value to the integrated value. The noise level of the injector is estimated by multiplying the transfer coefficient.

According to the present invention, the noise level of the injector is estimated by multiplying the integrated value of the absolute value or the square value of the movable portion seating speed within a unit time by the transfer coefficient. Irrespective of the value of the engine rotation speed, the total amount of momentum or kinetic energy when the movable part is seated within a unit time can be accurately grasped, and the injector noise can be detected with high accuracy.

According to a third aspect of the present invention, the movement speed detecting means performs differentiation or difference calculation of the movement speed of the movable portion with respect to a lift amount detection signal of a valve element that opens and closes an injection hole of an injector. , Is detected. According to the third aspect of the present invention, the moving speed of the movable portion is obtained by differentiating or calculating the lift amount signal of the valve body that opens and closes the injection hole of the injector. Thus, the momentum or kinetic energy of the valve element, which makes a large contribution, can be accurately grasped, and the injector noise can be obtained by a simple calculation.

The invention according to a fourth aspect of the present invention is configured such that the injector includes an electromagnetic valve for opening and closing an injection fluid passage for driving the valve body to open and close the valve body. Other than the seating speed of the valve body,
The seating speed of the solenoid valve is also detected.

According to the fourth aspect of the present invention, in addition to the seating speed of the valve body, the seating speed of the solenoid valve for driving the valve body is also detected. The momentum or kinetic energy of the valve section can be accurately grasped, and the injector noise can be obtained with higher accuracy.

Further, the invention according to claim 5 is characterized in that an extreme value of the moving speed of the movable portion is detected as a seating speed of the movable portion. According to the fifth aspect of the invention, when the movable part is seated, the speed instantaneously changes from a large absolute value to zero, so that the extreme value can be detected to detect the seating speed of the movable part.

Further, the invention according to claim 6 is characterized in that a seating speed of the solenoid valve is detected from a drive signal of the solenoid valve. According to the invention according to claim 6, the drive signal of the solenoid valve has a high correlation with the operating speed of the solenoid valve, and therefore, based on the drive signal as the operating speed detection signal without providing a lift sensor or the like, the pole of the signal is determined. The seating speed of the solenoid valve can be easily detected from the value or the like.

Further, the invention according to claim 7 is characterized in that the seating speed detecting means detects only the seating speed when the movable part is closed. According to the invention of claim 7, the valve is always seated when the valve is closed, and the maximum noise is generally generated when the valve is closed at the end of the main injection of the valve body. The contribution to the noise is large. Therefore, good estimation can be easily performed simply by detecting the seating speed only when the valve is closed and estimating the noise.

The invention according to claim 8 is characterized in that the seating speed detecting means detects the seating speed when the movable part is closed and when the movable part is opened. According to the eighth aspect of the present invention, if the noise is estimated by detecting the seating speed when the valve is opened as well as when the valve is closed, the estimation can be performed with higher accuracy.

According to a ninth aspect of the present invention, the noise level estimating means determines that the detected seating speed at the time of valve opening which has not been maintained at zero for a certain period of time immediately after the detection is determined by the integration. It is characterized by being excluded from the target. According to the ninth aspect of the present invention, the case where the speed of the movable part temporarily becomes zero due to noise or the like is excluded from the integration target, and the speed only when the user actually sits is integrated, and the noise is accurately determined. Can be estimated.

In the invention according to claim 10, the noise level estimating means determines that, among the detected seating speeds at the time of valve opening, the valve opening time from the start of valve opening to the seating is a fixed time or less. It is characterized in that it is excluded from the target of integration. According to the invention according to claim 10, when the valve opening time is too short compared to the valve opening time required from the start of valve opening to seating during normal times, it is determined that the seat is not actually seated. In this case, by excluding the noise from the integration target, the speed only when the user actually sits can be integrated, and the noise can be estimated with high accuracy. In the invention according to claim 11, the value of the transmission coefficient is set to a different value depending on at least one of the target movable part and at least one of when the valve is opened and when the valve is closed. It is characterized by.

According to the eleventh aspect of the present invention, depending on whether the movable portion is different or when the valve is opened or closed, even if the excitation force such as the momentum and the kinetic energy is the same, the level perceived as noise is obtained. May be different, so that the noise level can be estimated with extremely high accuracy by using the transfer coefficient corresponding to each situation. When the noise is estimated by integrating the absolute value or the square value of the seating speed, the same type is integrated for each movable part, and when the valve is opened and closed, and the transmission corresponding to each integrated value is performed. What is necessary is just to add the value obtained by multiplying the coefficients.

The invention according to claim 12 is characterized in that the value of the transfer coefficient is set according to the weight of the movable part. According to the twelfth aspect of the present invention, since the weight coefficient is changed and set in accordance with the weight of the movable part, it is possible to obtain the injector noise with the same calculation algorithm for injectors of different manufacturers and types. The versatility of the device can be improved.

Further, the invention according to claim 13 is characterized in that the value of the transfer coefficient is a 1/3 octave frequency characteristic. According to the thirteenth aspect of the present invention, the value of the transfer coefficient that is multiplied by the absolute value of the moving part speed or the integrated value of the square value is configured to be a 1/3 otarb frequency characteristic. The frequency characteristics can also be obtained, and the characteristics of the injector noise can be expressed more clearly.

The invention according to claim 14 is characterized in that the 1 /
The value of the transfer coefficient, which is a three-octave frequency characteristic, is a value determined by multiple regression analysis from experimental data. According to the invention according to claim 14, the 1/3
Since the value of the transfer coefficient, which is the octave frequency characteristic, is determined by a multiple regression analysis from experimental data and is a constant value, the injector noise suitable for an actual machine can be determined by a simple calculation.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment will be described with reference to FIGS. FIG. 1 shows a sectional structure and a system configuration of an injector to which the present invention is applied. In FIG. 1, an injector 1 is attached to a combustion chamber (not shown) of a direct injection diesel engine, and is connected to a common rail (not shown) by a high-pressure pump (not shown).
Is supplied to the injector 1 through the high-pressure pipe 2.

The fuel injection from the injector 1 is performed as follows. First, when the solenoid 3 is energized, the electromagnetic valve 4 moves to the solenoid side by the electromagnetic attraction. Then, the oil passage 5 closed by the solenoid valve 4 is opened,
High-pressure fuel flows into the solenoid valve chamber 6. As a result, the oil pressure balance in the injector is lost, and the hydraulic pressure applied to the needle valve 7 is relatively increased, so that the needle valve 7, the spacer 8 connected to the needle valve 7, and the piston 9 move to the electromagnetic valve 4 side. This allows
The injection hole 10 closed by the needle valve 7 is opened, and high-pressure fuel is injected from here.

On the other hand, when the power supply to the solenoid 3 is stopped, the electromagnetic attraction force is lost, the electromagnetic valve 4 is pushed back by the spring 11, and the oil passage 5 is closed. Then, since the high-pressure fuel is supplied again to the piston 9 having the large cross-sectional area, the spacer 8 and the needle valve 7 move in the opposite direction together with the piston 9 to close the injection hole 10 and the fuel injection ends. As described above, the needle valve 7, the spacer 8, and the piston 9 open and close the injection hole 10 in conjunction with each other, and the combination thereof is defined as a valve body B.

FIG. 2 shows an example of the behavior of the injector movable part during fuel injection and the result of observation of the vibration generated in the cylinder head at that time. Since the vibration of the cylinder head has a high correlation with the engine noise, FIG. 2 also shows the correlation between the behavior of the injector movable section and the generation of the engine noise. From FIG. 2, the vibration generation due to the seating of the injector movable portion on the stopper in one fuel injection occurs four times in the order of occurrence: the solenoid valve 4 opened, the valve body B opened, the solenoid valve 4 opened, and the valve body B closed. Among them, it can be seen that the vibration level generated when the valve body B is closed is the largest, and the contribution to noise is large. From this, it is expected that the injector noise can be approximately determined only by grasping the momentum or the kinetic energy when the valve body B is closed.

In the first embodiment, based on the above logic, the detection of the injector noise is performed as follows. As hardware, a lift sensor 12 for detecting a lift amount of the valve body B, and a lift signal from the lift sensor 12 are amplified and input through an amplifier 13 to perform arithmetic processing, thereby performing a noise level of the injector noise. Is provided with a noise detection circuit 13 for detecting the noise.

The detection of the noise level by the noise detection circuit 13 will be described with reference to the flowchart shown in FIG. In step 101, the lift signal is taken as input data for a certain period of time. The certain period is set so that the driving period of the injector 1, that is, the fuel injection period is included several times. The captured lift signal is, for example, as shown in FIG.
Has a waveform as shown above.

In step 102, the speed signal of the valve body B as shown in the lower part of FIG. 4 is obtained by performing differentiation or difference calculation on the lift signal. Therefore,
The lift sensor 12 and the function of the step 102 constitute a moving speed detecting means of the movable portion. Since the seating speed at the time of closing the valve appears as a negative minimum value in the speed signal, in step 103, the minimum value vi is included in the speed signal.
Then, an operation of picking up the amplitude and integrating the square value is performed.
A part of the function of the step 103 constitutes a seating speed detecting means.

In step 104, the speed minimum value vi
Of the valve body B previously input to the memory as the integrated value V of
By multiplying by the weight m, the total kinetic energy E when the valve body B is closed within a certain time can be obtained. As described above, by including the calculation of multiplying the weight m of the valve body B, the kinetic energy can be accurately calculated even when noise is detected for an injector having a different weight of the valve body B due to a difference in a maker or the like. And the versatility of the device can be increased.

Subsequently, at step 105, the injector noise P is calculated by multiplying the kinetic energy E obtained previously by the transfer coefficient H. The value of the transfer coefficient used here may be an overall value or a frequency characteristic such as a 1/3 octave band. The integration function of step 103 and the functions of steps 104 and 105 constitute noise estimation means.

Finally, at step 106, the obtained injector noise value (level) P is output. By calculating the injector noise using such a flow, it is possible to accurately determine the injector noise by a simple method without being affected by differences in operating conditions such as the engine speed and the presence / absence of pilot injection / post injection. it can.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the system configuration shown in FIG. 5, a lift sensor 12 and an amplifier 13 are provided as in the first embodiment.
In addition to the input of the lift signal of the valve body B amplified by the above, the drive signal of the solenoid valve 4 is input from the control circuit 14 and the seating noise of the solenoid valve 4 is calculated in addition to the seating noise of the valve body B, In addition, the seating noise is calculated not only when the valve is closed but also when the valve is opened, and the injector noise is estimated.

The detection of the noise level by the noise detection circuit 21 will be described with reference to the flowchart shown in FIG. The process is the same as that of the first embodiment up to the step of taking the lift signal of the valve body B in step 201 and performing the differentiation or difference calculation in step 202 to obtain the speed U of the valve body B. Not only the integrated value Uclose of the square value of the speed minimum value umini which is the seating speed at the time of the valve,
Also at the time of valve opening, the second embodiment differs from the first embodiment in that the integrated value Uopen of the square value of the maximum speed value umaxi, which is the seating speed, is calculated.

In step 204, the obtained speed integrated values Uopen and Uclose when the valve is opened and when the valve is closed are multiplied by different transmission coefficients H1 and H2, respectively.
When the valve is opened and when the valve is closed, the respective seating noises Popen and Pclose are calculated. The transfer coefficient used here may be data of the market value of the engine, or a value obtained by a method such as a multiple regression analysis from an actual engine noise measurement result may be input and used. In calculating the noise, an algorithm may be used in which the weight is multiplied by the weight of the valve body B and then multiplied by the transfer coefficient as shown in the first embodiment.

Next, the calculation of the solenoid valve noise from the solenoid valve drive signal is performed as follows. First, in step 205, a solenoid valve drive signal is captured for a certain period of time. This capturing time is the same as the capturing time of the lift signal of the valve element P, and the capturing timing is also the same. As an example of how to capture, wind a coil around the cable that sends the drive signal,
By taking in the voltage generated in the coil, a signal having a high correlation with the solenoid valve speed as shown in FIG. 7 can be obtained.

Next, in step 206, the square values of the maximum value vmaxj (when the valve is opened) and the minimum value vminj (when the valve is closed) of the drive signal are integrated. Subsequently, at step 207, different transfer coefficients G1 and G2 corresponding to the obtained integrated values Vopen and Vclose are multiplied to calculate the solenoid valve noises Sopen and Sclose when the valve is open and when the valve is closed.

Finally, at step 208, the noise Pop of the valve body B
The total injector noise P is obtained by adding en, Pclose, and the noises Sopen, Sclose of the solenoid valve 4, and the calculated noise value (level) is output in step 209. Here, it should be noted that when calculating the noise, the electromagnetic valve 4 has a seating phenomenon regardless of whether the valve is opened or closed, whereas the valve body B always has a seating phenomenon when the valve is closed. However, when the valve is opened, the seat may not be seated depending on the valve opening time. That is, if the valve opening time is short, the valve body B shifts to closing before colliding with the upper end wall (stopper), and in this case, no seating noise is generated. Therefore, when calculating the injector noise, it is necessary to exclude the speed of the valve body B without seating from the integration. FIGS. 8 and 10 show examples of the flow for excluding the valve body B speed without seating from the integration. The flow shown in FIG. 8 is the sum of the maximum speed values detected as the seating speed when the valve body B is opened, and those that do not have a speed 0 region for a certain period of time or more immediately after detection as those without seating. The flow shown in FIG. 10 is a flow chart in which the valve opening period from the start of valve opening to the seating of the valve opening at which the speed maximum value is detected is equal to or less than a predetermined time. Is excluded as not involving seating.

In the flow shown in FIG. 8, first, at step 301, a speed maximum value and a speed 0 duration immediately after that are obtained from the speed data. Specifically, the image shown in FIG. 9 is obtained. However, immediately after the maximum value umaxi at the time of the pilot injection, the valve immediately closes, so that the duration of the speed 0 at this time becomes zero. Also, the speed is 0 immediately after the local maximum value umaxi + 1 during the main injection.
Since no region exists, the speed 0 duration at this time is also zero. After the pair of the maximum value of the speed and the immediately following speed 0 duration is obtained, the process proceeds to the integration work of steps 302 to 306.

In step 303, it is determined whether or not the integration is possible. Here, the speed 0 duration t (u = 0) i has a predetermined value t.
If it does not exceed c, it is determined that there is no seating, and the step 304 of performing the integration calculation is skipped. Step 30
At 5,306, the above operation is performed for all local maxima (i = 1 to 1).
By performing step n), the speed data without seating is excluded from the integration, so that the exciting force of the valve body B when the valve is opened, that is, the noise level can be accurately obtained.

On the other hand, in the flow of FIG. 10, first, in step 311, the maximum speed value umaxi and the valve opening duration ti are obtained from the speed data. The valve opening duration is the time from when the valve starts to open and when it returns to the speed 0. In this case, as shown in FIG. 11, there is a possibility that a plurality of local maxima exist in one valve opening duration. In this case, the process of selecting the local maximal value closest to the end of the valve opening is performed. Do.

After the set of the maximum speed value umaxi and the valve opening duration ti is obtained as described above, the flow proceeds to the integration work of steps 312 to 316. In step 313, it is determined whether integration is possible. If the valve opening duration ti does not exceed a predetermined value tc ', it is determined that there is no seating, and step 314 for performing integration calculation is skipped. Steps 315 and 3
At 16, the above operation is performed for all local maxima (i = 1 to n). However, the time from valve opening to seating of the valve body B becomes shorter as the rail pressure increases, so that it is necessary to make tc 'a function of the rail pressure in order to perform the discrimination accurately. Also in this calculation method, since the speed data without seating is excluded from the integration, the noise level of the valve body B can be accurately obtained.

As described above, in the second embodiment, accurate noise calculation is performed for all four injector exciting forces shown in FIG. 2, so that it is possible to obtain injector noise with extremely high accuracy. it can. Note that, in the above-described embodiment, the noise is detected from the kinetic energy by integrating the square value of the sitting speed. However, the noise may be detected from the exercise amount by integrating the absolute value of the sitting speed. .

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an injector structure and a system configuration according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between behavior of an injector movable unit and generation of vibration according to the first embodiment.

FIG. 3 is a flowchart showing a routine for estimating injector noise according to the first embodiment;

FIG. 4 is a diagram illustrating an example of lift data of a valve body B according to the first embodiment.

FIG. 5 is a diagram showing an outline of an injector structure and a system configuration according to a second embodiment.

FIG. 6 is a flowchart illustrating a main routine of injector noise estimation according to the second embodiment.

FIG. 7 is a diagram illustrating a relationship between behavior of an injector movable unit and generation of vibration according to a second embodiment.

FIG. 8 is a flowchart showing an example of a subroutine for injector noise estimation according to the first embodiment;

FIG. 9 is a view for explaining data used in the above subroutine.

FIG. 10 is a flowchart showing another example of a subroutine for estimating injector noise according to the embodiment;

FIG. 11 is a view for explaining data used in the above subroutine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injector 4 Solenoid valve 7 Needle valve 8 Spacer 9 Piston 10 Injection hole 12 Lift sensor 14, 21 Noise detection circuit 22 Control circuit B Valve body

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasuyuki Asahara 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Naoki Takahashi 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Prefecture Nissan Motor Co., Ltd. F Terms (reference) 2G064 AA15 AB15 CC31 CC32 CC34 3G066 AA01 AA07 AB02 AD12 BA00 BA22 CC06T CC08T CC14 CC64T CC67 CC68U CD00 CD26 CE22 DC00 DC06

Claims (14)

[Claims] 1. A moving speed detecting means for detecting a moving speed of a movable portion of an injector, and a seating speed detecting means for detecting a seating speed when the movable portion is seated on a stopper based on the detected speed signal. And a noise level estimating means for estimating a noise level of the injector based on the detected seating speed. 2. The noise level estimating means accumulates an absolute value or a square value of a movable part sitting speed detected during a predetermined time, and multiplies the calculated absolute value of the velocity or the integrated value of the square value by a transfer coefficient. 2. The injector noise detecting device according to claim 1, wherein the noise level of the injector is estimated by using the same. 3. The moving speed detecting means detects the moving speed of the movable portion by differentiating or calculating a difference of a lift amount detection signal of a valve body that opens and closes an injection hole of an injector. Claim 1 or Claim 2
3. The injector noise detection device according to claim 1. 4. The valve according to claim 1, wherein the injector includes an electromagnetic valve for opening and closing an injection fluid passage for driving the valve body to open and close, and the seating speed detecting means detects a seating speed of the valve body as a seating speed of the movable part. The injector noise detecting device according to any one of claims 1 to 3, wherein a seating speed of the solenoid valve is also detected. 5. An apparatus according to claim 1, wherein an extreme value of a moving speed of said movable portion is detected as a seating speed of said movable portion.
The injector noise detection device according to claim 4. 6. The injector noise detecting device according to claim 4, wherein a seating speed of the solenoid valve is detected from a drive signal of the solenoid valve. 7. The seating speed detecting means detects only the seating speed when the movable portion is closed.
An injector noise detection device according to claim 6. 8. The injector noise according to claim 1, wherein said seating speed detecting means detects a seating speed when the movable portion is closed and when the valve is opened. Detection device. 9. The noise level estimating means, wherein the detected seating speed at the time of valve opening is a speed 0 or more for a certain period of time immediately after the detection.
9. The injector noise detection device according to claim 8, wherein the ones not maintained in (1) are excluded from the target of the integration. 10. The noise level estimating means excludes a detected seating speed at the time of valve opening whose valve opening time from the start of valve opening to seating is a predetermined time or less from the target of the integration. The injector noise detection device according to claim 8, wherein: 11. The value of the transmission coefficient is set to a different value depending on at least one of the target movable part and at least one of when the valve is opened and when the valve is closed. 1
0. The injector noise detection device according to any one of 0. 12. The transmission coefficient according to claim 2, wherein the value of the transmission coefficient is set according to the weight of the movable part.
The injector noise detection device according to any one of the above. 13. The apparatus according to claim 2, wherein the value of said transfer coefficient is a 1/3 octave frequency characteristic.
3. The injector noise detection device according to any one of 2. 14. The injector noise detecting device according to claim 13, wherein the value of the transfer coefficient, which is the 1/3 octave frequency characteristic, is a value obtained by a multiple regression analysis from experimental data.