JP3855869B2 - Method for measuring the injection amount of each nozzle of a fuel injection nozzle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for individually measuring an injection amount for each injection port of a multi-injection fuel injection nozzle used in a diesel engine or the like.
[0002]
[Prior art]
In general, in a fuel injection nozzle for a diesel engine, a plurality of relatively small-diameter nozzle holes are formed at the tip of the nozzle, and fuel is simultaneously injected from the nozzle holes.
[0003]
As shown in FIG. 3, the conventional fuel injection nozzle injection amount measuring apparatus pumps and supplies the fluid F stored in the tank 51 to the fuel injection nozzle 53 through the supply pipe 55 by the pump 52. The fluid F is ejected from each ejection port, and the ejected fluid F is collected in the tank 51 and ejected from all the ejection ports by the flow rate measuring device 54 provided between the pump 52 and the fuel injection nozzle 53. The total (total flow rate) was to be measured. A similar technique is disclosed in Japanese Patent Laid-Open No. 8-121287.
[0004]
However, in recent years, the nozzle has become smaller due to the requirement of exhaust gas regulations, making it difficult to process. In order to make the fuel injection amount from each nozzle hole uniform in this state of the art, it is necessary to measure the injection amount for each nozzle hole and evaluate the variation of each injection amount. On the other hand, if this is not performed, even if the injection amount of the entire nozzle matches the appropriate value, the injection amount varies from nozzle to nozzle, and the fuel spray state also varies. As a result, exhaust gas is deteriorated. According to the experiment, there may be a variation of 20% or more with respect to the reference injection amount for each nozzle.
[0005]
From this point of view, there is a conventional injection amount measuring apparatus as shown in FIG. That is, the fluid is supplied to the fuel injection nozzle 53 in the same manner as described above, and the fluid F injected from the injection port is individually guided to the measuring cylinder 58 through the straw-like pipe 57 for each injection port 56, and the measuring cylinder is set for a certain period of time. The volume of the fluid F collected in 58 is measured, and each volume for each nozzle is compared, and the variation in the injection amount for each nozzle is evaluated.
[0006]
[Problems to be solved by the invention]
However, according to this method, the operation of accumulating the fluid in the graduated cylinder is performed by changing the time in order for each nozzle, so that the measurement conditions such as the variation in the amount of fluid supplied from the fluid supply pump and the variation in the storage time vary. Is likely to occur, and it is difficult to ensure measurement accuracy.
[0007]
Accordingly, the present invention has been devised in view of the above problems, and an object of the present invention is to enable highly accurate measurement when measuring the injection amount for each nozzle hole.
[0008]
[Means for Solving the Problems]
According to the present invention, provided separately For each injection port of the fuel injection nozzle having a plurality of nozzle holes, a plurality of fluid conduit having an outlet for discharging the inlet and the fluid introducing a fluid ejected from the spray port A plurality of containers individually provided for each of the fluid pipes for storing the fluid discharged from the outlet of the fluid pipe; and the fluids respectively provided in the fluid pipes and introduced into the fluid pipes. A plurality of three-way valves that can be switched to the container side or the external side to be guided to either the outlet side or the external discharge side of the fluid pipe, and switching for simultaneously switching each of the three-way valves to the container side or the external side A plurality of weight measuring means for measuring the weight of the container and the fluid stored in the container, and a fluid to be supplied to the fuel injection nozzle. tank A fuel injection nozzle injection amount measuring device comprising a pump for pumping the fluid in the tank to the fuel injection nozzle through a supply passage, and the fuel injection nozzle with the nozzles being open at all times. A method of measuring the injection amount of each of the injection ports of the fluid injected from the fuel injection nozzle by pumping the fluid to the injection nozzle by the pump, and simultaneously switching all the three-way valves to the outside by the switching means. A step of switching, and the fluid in the tank is supplied to the fuel injection nozzle through the supply passage by the pump to inject the fluid from the injection ports, and the injected fluid is supplied to the fluid pipes and the three-way Discharging through the valve and then discharging to the outside; measuring each initial weight of each container by each of the weight measuring means; and All the three-way valves are simultaneously switched to the container side by the exchange means, the fluid introduced into the fluid pipes is discharged to the containers, the fluid is stored in the containers, and the three-way valve is switched to the container side. After a predetermined time has elapsed, all the three-way valves are simultaneously switched to the outside by the switching means, and the fluid introduced into the fluid pipes is discharged to the outside to stop the fluid from being stored in the containers. Measuring the post-retention weight for each of the containers by the weight measuring means, calculating the difference between the post-retention weight and the initial weight for each of the containers, and calculating the injection amount for each of the nozzles. And a step of measuring. An injection amount measuring method for each injection port of the fuel injection nozzle is provided.
[0011]
According to the present invention, a fluid pipe, a three-way valve, and a container are provided for each nozzle, and all three-way valves are simultaneously switched to perform a fluid storage operation in the container. Measurements can be performed at the same time and under the same measurement conditions, greatly improving measurement accuracy.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0013]
FIG. 1 shows a fuel injection amount measuring apparatus according to this embodiment. Reference numeral 1 denotes a fuel injection nozzle to be measured, only a part of which is shown. Only the nozzle body 2 of the fuel injection nozzle 1 is evaluated. In this case, the internal needle valve, the return spring, etc. are removed. The nozzle body 2 is fixed at a fixed position by means not shown. A plurality of (for example, 5 to 8) nozzle holes 4 having a relatively small diameter (for example, φ0.1 to 0.3 mm) are formed in the pointed portion 3 at the tip of the nozzle body 2 in an obliquely downward direction. A needle valve chamber 5 for accommodating a needle valve and a return spring is formed in the central portion of the nozzle body 2, and oil for accommodating a taper portion (pressure acting portion) of the needle valve is provided in the middle of the needle valve chamber 5. A reservoir chamber 6 is formed, and a fuel introduction passage 7 communicates with the oil reservoir chamber 6. Originally, in the fuel injection nozzle, the needle valve is raised by the pressure of the fuel introduced from the fuel introduction passage 7 into the oil sump chamber 6 and the fuel injection is performed from the injection port 4. In this measurement test, the fuel introduction passage 7 is illustrated. The test fluid F (oil in this embodiment) is supplied to the needle valve chamber 5, and the fluid F is simultaneously ejected from the nozzles 4.
[0014]
In addition, in some cases, the influence of the needle valve or the like may be evaluated. In this case, a needle valve and a return spring (not shown) are set in the needle valve chamber 5, and fuel is introduced as indicated by a broken line in the figure. A fluid F is supplied to the passage 7.
[0015]
The fluid F is stored in the tank 8. The tank 8 is provided with a temperature control device so that the temperature of the fluid F can be adjusted and the temperature can be kept constant. The fluid F stored in the tank 8 is pumped by the pump 9 to the fuel injection nozzle 1 through the supply pipe 10. The pump 9 is a high-pressure pump, and the pressure of the fluid F is increased to a predetermined high pressure (for example, 10 to 160 MPa) and pumped. This is in order to approach the same conditions as during actual fuel injection. The pump 9 is provided with a pressure control device so that the pressure of the fluid F can be adjusted and the pressure can be kept constant. In the middle of the supply pipe 10, there is provided a total injection amount measuring means for measuring the total injection amount of all the nozzle holes 4, and in this embodiment, a flow rate measuring device 11 for measuring the total injection flow rate. The supply pipe 10 communicates with the needle valve chamber 5 and directly supplies the fluid F to the needle valve chamber 5.
[0016]
The configuration of the fluid supply apparatus including the tank 8, the pump 9, the supply pipe 10, and the flow rate measuring device 11 is the same as that of the conventional apparatus shown in FIG.
[0017]
The fluid F ejected from the nozzle 4 is stored in the container 13 through the fluid pipe 12. However, in the present embodiment, unlike the conventional case (FIG. 4), the fluid pipe 12 and the container 13 are individually provided for each nozzle hole 4 or all the nozzle holes 4. That is, the fluid pipes 12 and the containers 13 are provided as many as the number of nozzle holes, one for each nozzle hole 4. In the figure, only two fluid pipes 12 and a container 13 are representatively drawn clearly.
[0018]
The fluid pipe 12 is made of, for example, a metal pipe and is a straight pipe in the illustrated example, but a curved pipe, a bent pipe, or the like can be used as appropriate. The fluid pipe 12 is fixed at a fixed position by appropriate fixing means. The fluid pipe 12 has an inlet 14 for introducing the fluid F ejected from the nozzle 4 and an outlet 15 for discharging the fluid F. At least the outlet 15 is located below the inlet 14, and the fluid F is contained in the pipe. It is designed to flow down due to gravity. In the present embodiment, the fluid pipe 12 is disposed so as to be inclined downward along the fluid flow direction. The inlet 14 is as close as possible to the nozzle 4 or contacts the pointed portion 3 around the nozzle 4 so as to introduce the fluid F ejected from the nozzle 4 without leakage.
[0019]
The container 13 is in the shape of a bottomed cylinder whose upper side is open, and is positioned directly below the outlet 15 and introduces the fluid F discharged from the outlet 15 and flowing down through the upper opening. A weight measuring means for measuring the weight of the container 13 and the fluid F stored therein, that is, a weight measuring device 16 is provided. The weight measuring devices 16 are individually provided for each container 13, that is, one weight 13 is provided for each container 13 as many as the number of containers (that is, the number of nozzles). Each container 13 is placed on each weight measuring device 16. In the present embodiment, an electronic balance is used as the weight measuring device 16 in order to perform highly accurate measurement.
[0020]
Each fluid pipe 12 is provided with a three-way valve 17. That is, one three-way valve 17 is provided for each fluid pipe 12 as many as the number of fluid pipes 12 (that is, the number of nozzles). The three-way valve 17 has a discharge port (not shown), and the discharge port is connected to the tank 8 via a fluid discharge pipe 19.
[0021]
In the present embodiment, the three-way valve 17 is an electromagnetic valve, and is simultaneously turned ON / OFF by a controller 18 as a switching means and switched to one side A or the other side B. When the three-way valve 17 is turned on and switched to the one side A, the fluid F introduced into the fluid pipe 12 is guided to the outlet 15 side of the fluid pipe 12. On the other hand, when the three-way valve 17 is turned off and switched to the other side B, the fluid F introduced into the fluid pipe 12 is guided to the tank 8 (that is, the external discharge side) through the discharge port and the fluid discharge pipe 19.
[0022]
The controller 18 includes a timer 22 as time measuring means, and can automatically switch ON / OFF of the three-way valve 17 at the same time as the set time of the timer 22 elapses. The controller 18 is also provided with a manual switch 23, and the three-way valve 17 can be manually turned on / off by turning on / off the manual switch 23.
[0023]
The outlet of each container 13 is connected to the tank 8 via the discharge pipe 20 so that the fluid F in each container 13 can be returned to the tank 8. The discharge pipes 20 extending from the respective containers 13 are joined on the way, and a switching valve 21 is provided on the downstream side of the joining part. At the time of measurement, the switching valve 21 is closed, and the fluid F can be stored in the container 13. Then, the switching valve 21 is opened at an appropriate time not during measurement, and the fluid F in the container 13 is returned to the tank 8. The switching valve 21 may be manually opened and closed, or may be automatically opened and closed by the controller 18.
[0024]
Next, a method for measuring the injection quantity for each nozzle hole and a method for evaluating the injection quantity for each nozzle hole according to the present apparatus will be described.
[0025]
First, fluid F is continuously supplied to the fuel injection nozzle 1 by the pump 9 with all the three-way valves 17 switched to the other side B. Then, the fluid F is ejected from each nozzle 4, introduced into each fluid pipe 12, and returned from each three-way valve 17 to the tank 8 through the fluid discharge pipe 19. This fluid circulation state is continued for a predetermined time, and warming up for spreading the fluid F through all the fluid paths is performed. From this time, the temperature and pressure of the fluid F are controlled to be constant by the temperature control device of the tank 8 and the pressure control device of the pump 9, and the total injection flow rate from all the injection ports 4 is constantly measured by the flow rate measuring device 11. .
[0026]
During this warming up, each weight measuring device 16 measures the weight of each container 13, that is, the initial weight W0. In addition, although the total weight of the container 13 and the fluid F in it is measured here, the weight of the container 13 will be subtracted so that it may understand later.
[0027]
Thereafter, the timer 22 is set to a predetermined time (for example, 1 minute, which is called a measurement time), and all the three-way valves 17 are simultaneously switched to the one side A by the manual switch 23. Then, the fluid F ejected from each nozzle 4 and introduced into each fluid pipe 12 is discharged from the outlet 15 and is sequentially stored in each container 13.
[0028]
When the measurement time has elapsed, an OFF signal is automatically sent from the controller 18 to all the three-way valves 17, and all the three-way valves 17 are automatically switched to the other side B simultaneously. At the same time, the fluid F introduced into the fluid pipe 12 is guided to the tank 8 and the fluid storing operation in the container 13 is stopped.
[0029]
Thereafter, after waiting for dripping of the residual fluid in the fluid pipe 12, the weight for each container 13, that is, the post-storage weight W <b> 1 is measured by each weight measuring device 16. Then, for each container 13, the initial weight W0 is subtracted from the post-storage weight W1, and the measured weight W (= W1-W0) that is the difference is calculated. Since the post-retention weight W1 is also the total weight of the container 13 and the fluid F in the container 13, the weight of the container 13 is subtracted by this subtraction, and substantially the amount of fluid increased by the storage operation. Only the weight of F, that is, the injection amount of the fluid F injected during the measurement time is measured.
[0030]
Thereafter, by comparing the measured weight W for each container 13, that is, for each nozzle 4, the variation in the injection amount for each nozzle 4 is evaluated. At this time, the measurement weight W for each nozzle 4 may be divided by the measurement time to compare and evaluate as a unit of flow rate.
[0031]
Thereafter, when it is desired to repeat the same measurement work, the post-storage weight W1 may be replaced with the initial weight W0 and the above work may be repeated. If necessary, the switching valve 21 is opened to discharge the fluid F in the container 13 to the tank 8 so that the fluid F for the next measurement can be stored in the container 13. It is necessary to discharge the fluid F in the container 13 so as not to exceed the allowable load of the weight measuring device 16 at least during the storage operation. However, if the allowable load is not exceeded, it is not always necessary to discharge the fluid F every time.
[0032]
FIG. 2 shows an example of the result of a measurement test performed using the present apparatus and method. The test was performed on the fuel injection nozzles having 6 nozzles, and the measured weight W for each nozzle was divided by the measurement time and compared as a unit of flow rate. The measurement was performed several times. The horizontal axis of the graph is the nozzle number. The vertical axis represents the flow rate (g / min). From this result, no. It can be seen that one nozzle hole has a larger flow rate variation than the other nozzle holes, and is defective.
[0033]
As described above, according to the injection amount measuring apparatus according to the present embodiment, since the injection amount measurement is simultaneously performed for all the injection holes, there is no variation in measurement conditions, and measurement can be performed under the same conditions. Thereby, the measurement accuracy can be greatly improved.
[0034]
In addition, since the injection amount variation for each nozzle can be evaluated with high accuracy, it can greatly contribute to the purification of exhaust gas.
[0035]
And since all the nozzles can be measured at the same time, the total measurement time can be greatly reduced compared to the case where each nozzle is measured in turn, making it possible to apply to the mass production line and to perform 100% inspection in the mass production line. The reliability of mass-produced products can be greatly improved.
[0036]
In addition, since the configuration of the fluid supply apparatus from the tank 8 to the fuel injection nozzle 1 is the same as that of the conventional apparatus shown in FIG. 3, the apparatus according to the present embodiment can be used for the conventional apparatus. It is possible to avoid equipment modification and increase in cycle time. Since the total injection amount of the fuel injection nozzle alone or from all the injection holes can be measured, the evaluation and management of the fuel injection nozzle alone can be performed as usual.
[0037]
Various other embodiments of the present invention are conceivable. For example, a liquid other than oil can be used as the test fluid, or a gas such as air can be used. When gas is used, the container can be a sealed container, the pressure in the container can be measured, and the increase in pressure in the container accompanying the injection can be regarded as the injection amount for measurement. The three-way valve is not limited to a solenoid valve, and may be a mechanical valve. The switching means for simultaneously switching the three-way valves may be a mechanical mechanism that switches the valves by manual operation. In this embodiment, the weight of the fluid stored in the container is measured, but the volume of the fluid may be measured.
[0038]
【The invention's effect】
In short, according to the present invention, when measuring the injection amount for each nozzle of the fuel injection nozzle, an excellent effect that the measurement accuracy can be greatly improved is exhibited.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an injection amount measuring apparatus according to an embodiment of the present invention.
FIG. 2 is a graph showing the results of a measurement test performed using the injection amount measuring apparatus according to the embodiment of the present invention.
FIG. 3 is a configuration diagram showing a conventional injection amount measuring apparatus.
FIG. 4 is a block diagram showing a conventional injection amount measuring device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel injection nozzle 4 Injection hole 8 Tank 9 Pump 12 Fluid pipe 13 Container 14 Inlet 15 Outlet 16 Weight measuring instrument 17 Three-way valve 18 Controller 22 Timer A One side B Other side F Fluid W0 Initial weight W1 Weight after storage

Claims (1)

Individually provided For each injection port of the fuel injection nozzle having a plurality of nozzle holes, a plurality of fluid conduit having an outlet for discharging the inlet and the fluid introducing a fluid ejected from the spray port, in each fluid conduit A plurality of containers provided separately for storing the fluid discharged from the outlet of the fluid pipe, and provided in each of the fluid pipes, and the fluid introduced into the fluid pipes on the outlet side of the fluid pipe Or a plurality of three-way valves that can be switched to the container side or the external side to lead to either the external discharge side,
Switching means for simultaneously switching each of the three-way valves to the container side or the external side , and a plurality of weight measurements for individually measuring the weight of the container and the fluid stored in the container. An injection amount measuring device for a fuel injection nozzle comprising means, a tank storing a fluid to be supplied to the fuel injection nozzle, and a pump for pumping the fluid in the tank to the fuel injection nozzle through a supply passage In use, with each nozzle hole of the fuel injection nozzle always open, fluid is pumped to the fuel injection nozzle by the pump, and the injection amount of the fluid injected from the fuel injection nozzle for each nozzle hole is measured. A method,
Switching all the three-way valves to the outside simultaneously by the switching means;
The fluid in the tank is supplied to the fuel injection nozzle through the supply passage by the pump to inject the fluid from the injection ports, and the injected fluid is allowed to pass through the fluid pipes and the three-way valves. A step of discharging to the outside, and
Measuring the initial weight for each of the containers by the weight measuring means,
All the three-way valves are simultaneously switched to the container side by the switching means, the fluid introduced into the fluid pipes is discharged to the containers, and the fluid is stored in the containers;
After a predetermined time has elapsed from when the three-way valve is switched to the container side, all the three-way valves are simultaneously switched to the external side by the switching means, and the fluid introduced into the fluid pipes is discharged to the outside. Stopping the storage of fluid in the container;
Measuring the post-retention weight for each of the containers by the weight measuring means, calculating the difference between the post-storage weight and the initial weight for each of the containers, and measuring the injection amount for each of the nozzles;
An injection amount measuring method for each injection port of the fuel injection nozzle.

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