JP2509071Y2 - Fuel injection nozzle for adjusting flow rate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a shape of a flow rate adjusting nozzle for adjusting a fuel injector as a component of an injection control system for improving efficiency of a gasoline engine to a predetermined standard.

Conventional technology A fuel injection control system has been developed in recent years in order to improve the efficiency and reduce pollution of gasoline engines, and the air flow rate flowing into the engine as the throttle angle is adjusted is measured by a Karman vortex flowmeter. On the other hand, the mass flow ratio of gasoline is controlled to an optimum value, for example, 14.7: 1. In this case, fuel gasoline is injected by a fuel injector, transferred to a cylinder as a mixed gas with the air, and pressurized and ignited. The fuel injector injects gasoline from an opening formed by a valve seat and a plug pressed against the valve seat by a spring force. The plug is attracted by an electromagnetic force against the spring force and opens. . In the control operation, a pulse width modulated intermittent signal of a constant voltage is applied to the electromagnetic coil. Since the injection pressure is constant, the flow rate is expressed as an integral value of the liquid passage time per unit time of the liquid passage amount which is opened by the application signal and is passed. Therefore, the delay in the operation of the plug affects the flow rate accuracy of the test liquid. Since the spring force is related to this operation delay, when adjusting the fuel injector, the spring force is set so that the specified volume is obtained when the test liquid of a constant pressure is flowed for a predetermined time, but the applied signal at this time is For example, the pulse voltage has a constant peak value and a constant pulse width at a constant frequency.

A specific example of an actual fuel injector adjusting method will be described with reference to FIG. The test liquid is a liquid with a high flash point similar to that of gasoline, and is pressure-fed from a supply source (not shown) and passes through the throttle valve 1, filter 2, regulator 3, damper 4 and header 5 to adjust the flow rate to a constant flow rate. It flows into the rod chamber 8. During this time, the pulsation contained in the test liquid is removed by the damper 4 and the accumulator 6 arranged in the header 5, and the pressure of the test liquid is measured by the precision pressure gauge 7.

FIG. 3 is a diagram showing an outline of a related configuration of the flow rate adjusting rod chamber 8, the micrometer head 9 and the fuel injector 10, in which the inner chamber 84 is disposed above the outer casing 81 of the flow rate adjusting rod 8. The inner chamber 84 is provided with an inflow port 82 for introducing the test liquid and an air vent 83 for communicating with the air vent valve 16 to remove air in the test liquid. A chamber 85 and an outflow port 89 for introducing the test liquid from the inner chamber 85 to the fuel injector 10 are provided. The inner chamber above
A distribution rod 86 is slidably inserted between 84 and the lower inner chamber 85. The distribution rod 86 is a ball seat 861 in order from the top,
It is composed of an upper distribution rod 862, a valve 864, a lower distribution rod 863, and an outflow groove 865, and a space between a ball seat 861 and an upper inner chamber 84 is extended by a spring 87, and normally a valve 864 is used to form the upper inner chamber 84
The flow of test liquid between the inner chamber 85 and the lower inner chamber 85 is closed. Further, the cross section of each of the upper flow rod 862 and the lower flow rod 863 has a cylindrical outer groove 866 as shown in the sectional view taken along the arrow AA (FIG. 4), and the test liquid flows through the outer groove 866. To do. A connecting rod 93 that slides in a liquid-tight manner is in contact with the upper part of the ball seat 861. The connecting rod 93 is fixed via a ball 92 to a fixing frame 90.
The displacement amount of the flow rod 86 can be read by being connected to the micrometer head 9 arranged at 0.
In addition, a packing 88 is inserted in the lower portion of the inner chamber 85 of the outer casing 81, and the inlet 10 of the fuel injector 10 to be adjusted is inserted.
11 is inserted liquid-tightly. The fuel injector 10 has a cylindrical shape having an inflow port (1011) in an upper part and an outflow port 106 in a lower part, and a pipe 102, a coil spring 103, and a plug 105 are sequentially arranged in an axial flow passage from the inflow port (1011) side. Is provided. The pipe 102 is loosely inserted in the flow passage, and the upper portion thereof is in contact with the outflow groove 865 of the lower flow rod 863. Also,
A coil 104 for electromagnetically attracting the plug 105 is provided inside the housing 101 in the vicinity of the plug 105, and normally the coil spring 1
The outlet 106, which is pressed by 03 and consists of a valve seat 1013, is closed. When the coil 104 is energized, the plug 105 is attracted and opens. The test liquid flowing through the fuel injector 10 due to the open circuit flows into the measuring flask 110 of the measuring device 11, and the capacity Qcc between the photoelectric tubes 12 and 13 indicating the reference capacity of the measuring flask.
Calculate the flow rate by measuring the time. The measured test liquid is discharged to the drain tank 15 by opening the solenoid valve 14.

In the adjusting device described above, in displacing the coil spring 103 by the micrometer head 9 to pass the test liquid, the air in the inner chamber 84 of the flow rate adjusting rod chamber 8 is vented from the air vent 83. It is evacuated through 16 by a vacuum pump (not shown) or the like. However, since the air contained in the test solution causes a large error in the measurement accuracy, in order to prevent this, a DC voltage is applied to the coil 104 before the adjustment, and the outlet 1
The maximum open area of 06 removes the air contained in the test liquid flow passage after the inner chamber 85, and passes the solenoid valve 14 to the drain tank.
Eject 15

Problems of Prior Art Normally, the fuel injector is adjusted for all of the above adjustments completed in the mass production process.
There are many vacant chambers in the flow rate adjusting rod chamber of the conventional technology, and the air is not completely removed every time a workpiece is automatically mounted.As a result, there are many variations in precision, the adjustment yield is poor, and the productivity is reduced, reducing costs. It was a big obstacle in the process.

Means for Solving the Problems The present invention has been made in view of the above problems, and minimizes the space in which air is retained in the flow passage that introduces the test liquid into the fuel injector to be adjusted, and in addition to the conventional technique. The flow rate adjusting rod is a nozzle type, and the test liquid is circulated and the air that stays in the space of the insertion portion is made to be entrained by the nozzle jet flow while being introduced from the nozzle to the fuel injector to be adjusted. Provided is a nozzle for flow rate adjustment, in which a liquid is ejected to the outside of a nozzle, and the jet flow is introduced into a space existing when a work is mounted and then introduced into a fuel injector to be adjusted.

Embodiment FIG. 1 (a) is a sectional view for explaining the structure of a fuel injector adjusting nozzle 20 of the present invention, and FIG. 1 (b) is an external view of the adjusting nozzle as seen from the direction of an inlet 215. . The adjustment nozzle 20 corresponds to the flow rate adjusting rod 8 sandwiched between the microphone meter head 91 and the fuel injector 10 to be adjusted described in the prior art shown in FIG. 3, and is common to these prior arts. The same reference numerals are given to the elements to be described, and the description thereof will be omitted. In the figure, the adjusting nozzle 21 is a cylindrical body having an inflow port 215, and a nozzle introducing part 211 and a nozzle tip part 212 thinner than the nozzle introducing part 211 are integrally arranged in the axial direction. Tip 212
Is inserted into the inlet 1011 of the fuel injector 10 in the same manner as the lower flow rod 863 of the prior art, and the pipe 102
Is in contact with. This adjusting nozzle 21 is an adjusting nozzle support 22.
It is slidably inserted in a liquid-tight manner into a recessed portion 221 formed in the hole and an insertion portion 223 coaxial with the recessed portion. The adjustment nozzle 21 and the adjustment nozzle support 22 are extended by the coil spring 23 inserted into the recess 221 coaxially with the nozzle introduction portion 211, and the adjustment nozzle 21 abuts the micrometer head 91 via the ball 92. Further, an elliptical hole 213 is bored on the diameter upper wall surface of the nozzle tip portion 212, a groove portion 214 having a groove is bored on the tip surface diameter, and with the pipe 102 of the fuel injector 10,
The adjustment nozzle 20 and the fuel injector 10 to be adjusted have a packing 222 press-fitted into the lower end surface of the adjustment nozzle base 22 coaxially with the insertion portion 223, and an end face of the inflow port 1011 of the fuel injector 10 to be adjusted. Insertion part at this time
A cavity 224 is formed between 223 and the packing 222. A slight gap is formed between the nozzle tip portion 212 and the groove portion 214 with the inner wall of the inflow port 1011 to form a test liquid flow passage, and this flow passage communicates with the cavity 224.

Next, the operation of the present invention will be described with reference to FIG. First, prior to the test, a test liquid is introduced to remove air from the fuel injector 10 under test. Inlet
The test liquid introduced from 215 passes through the adjustment nozzle 21 and the inside of the nozzle introduction portion 211, is ejected on the diameter from the oval hole 213, and is formed by the nozzle tip portion 211 and the inner wall surface of the inflow port 1011. It is introduced into the fuel injector 10 under test from the groove portion 214 through the pipe 102. At this time, the air remaining in the cavity portion 224 formed by the nozzle tip portion 212 and the insertion portion 223 is entrained by the jet flow and becomes a multiphase flow of the air and the test liquid, and the inflow port 1011 of the fuel injector 10 and the nozzle tip portion 212. Through the circular gap formed by and again into the fuel injector 10 to be tested through the pipe 102 and the flow direction is changed. The multiphase flow that has flowed out by the jet flow flowing out through the above-mentioned path is discharged to the drain tank 15 through the solenoid valve 14, and if the test liquid is kept flowing for a predetermined time, the air at the connection between the adjustment nozzle 20 and the fuel injector 10 is removed. As a result, the flow rate test of the fuel injector 10 can be performed accurately. Note that the effect was insufficient when the elliptical hole 213 was formed into a circle or a plurality of circular holes. Also, when the rectangular hole is used, the effect of the present invention can be obtained, but it is meaningless in the work.

Effect As described above, according to the fuel injector flow rate adjusting nozzle of the present invention, unlike the prior art, it is not necessary to provide the air vent port 83 to evacuate with the vacuum pump, the structure is simple and the air is completely eliminated. Therefore, the adjustment yield is remarkably improved, the operability is excellent, and the economical effect is extremely large.

[Brief description of drawings]

FIG. 1 illustrates the structure of a fuel injector flow rate adjusting nozzle of the present invention. FIG. 1 (a) is a sectional view,
FIG. 2B is an external view of the adjusting nozzle, FIG. 2 is a block diagram showing the adjusting method of the fuel injector, and FIG. 3 is
Schematic explanatory diagram of a conventional adjusting device for a fuel injector,
FIG. 4 is a sectional view taken along the line AA of FIG. 21 …… Adjusting nozzle, 212 …… Nozzle tip, 213 …… Oval hole, 214 …… Groove with groove, 22 …… Adjusting nozzle pedestal, 2
3 ... Coil spring.

Claims (1)

(57) [Scope of utility model registration request] 1. A fuel injector for opening a plug pressed against a valve seat by the force of a spring by an electromagnetic force against the spring force to inject a test liquid of a constant pressure supplied from an inlet, and the spring. For adjusting the flow rate of the fuel injector for supplying a test liquid to the fuel injector detachably disposed between the micrometer head and the inlet of the fuel injector. In the nozzle, one end is in contact with the micrometer head and the other end is a small-diameter cylindrical body that can be inserted into the inflow port. The end face has a groove that opens in the radial direction and an oval hole that communicates with the test liquid supply passage in the middle. An adjusting nozzle having a nozzle introducing portion having a nozzle tip portion having a hole formed therein, and an adjusting nozzle slidably inserted into the adjusting nozzle. A fuel injector flow rate adjustment, characterized in that it comprises an adjusting nozzle receiving base that is in liquid-tight contact with the inlet end face of the injector, and a coil spring that applies a force in a direction separating the adjusting nozzle receiving base and the adjusting nozzle. Nozzle.