JPH04102443U - Vibration-resistant fuel injection pressure sensor - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose of this invention is to provide a fuel injection pressure sensor that prevents the influence of vibration and has improved durability and reliability. [Structure] A strain gauge is attached to a special fitting metal fitting that has a through hole in the center and a constriction with a square cross section in part, and pipe threads are provided at both ends, and the outside of the strain gauge is fitted into the constriction of the square cross section. It is then tightened with two pieces of hardware that sandwich and cover the main part.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a vibration-resistant fuel injection pressure sensor for diesel engines.

0002

[Conventional technology]

The fuel injection pressure of a diesel engine affects the operation of the fuel injection system, which determines the quality of the fuel. This information is important for determining the situation, but the sensors that have been used conventionally are The strain gauges 20, 22 (see Figure 3) and the two-part hardware 23 are integrated into the joint hardware 24. Since it was fixed with something equivalent to a coagulant, it was not easy to replace, and it took a lot of machinery to replace it. There were additional conditions attached, such as suspension of the vehicle. Figure 4 shows the configuration of the fuel injection pressure detection device. . In the figure, 1 is the fuel cam, 2 is the fuel injection pump, 3 is the fuel injection pipe, and 4 is the nozzle. holder, 5 is a cylinder cover, 6 is a combustion chamber, 7 is an amplifier, 8 is an A/D converter, 9 1 is a computer, and 10 is an output device (printer, plotter, etc.).

0003 Next, the operation of the conventional example will be explained. When the fuel rotates once, the plunger (not shown) of the fuel injection pump 2 is pushed up. The fuel is pushed out through the fuel injection pipe 3 and is shown at the tip of the nozzle holder 4. is injected into the combustion chamber 6 from a nozzle that does not Fuel injection pressure is measured using fuel injection pipe 3. and the two-part metal fitting 11 attached to the joint metal fitting 12 between the nozzle holder 4 and the strain gauge. Detection is performed by a sensor 13 composed of 20 and 22 (see FIG. 3). Se The output from the sensor 13 is amplified by the amplifier 7 and converted to a digital value by the A/D converter 8. The data is then processed by the computer 9 and input to the output device 10.

0004

[Problem that the idea aims to solve]

The known sensor 13 is not durable because it is made only to improve accuracy. In addition, in the actual machine, the sensor 13 and its The two-part metal fitting 11 may fall off or rotate due to failure to protect the conductor wire (not shown). Therefore, these breakages occur in a short period of time. Therefore, the sensor 13 and the two-part hardware 1 1 is fixed with something equivalent to a coagulant.

[0005] The purpose of this invention was to eliminate the above-mentioned problems, eliminate the effects of vibration, and improve durability and reliability. An object of the present invention is to provide a vibration-resistant fuel injection pressure sensor as described above.

[0006]

[Means to solve the problem]

The vibration-resistant fuel injection pressure sensor of the present invention has a cylindrical shape with a hole passing through it along the axis. A joint that has pipe threads on both ends and a constriction with a square cross section in part. The hardware and the strain gauge attached to the outer surface of the central part of the fitting hardware and coated on the surface. 20, and the cross-sectional shape of the joint hardware fits into the constriction of a square, and A two-part hardware consisting of two pieces that cover and sandwich the central part, and an inner surface of the two-part hardware. It is characterized by consisting of a strain gauge 22 affixed to the.

[0007]

[Effect]

Connect one end of the fitting to the fuel injection pipe 3 using the pipe thread, and connect the other end to the fuel injection pipe 3 with the pipe thread. The fuel is connected to the injection valve via a pipe and injected into a through hole provided along the axis. You can pay the fee. The two-part metal fitting is attached to the constriction of the square cross-section of the fitting metal fitting. The rigidity of the fitting is increased because it is fitted and tightened covering the center of the fitting. This can stop the rotation, prevent the effects of vibration, and prevent the two-part hardware from falling off. Wear. When the fuel is injected into the through-hole of the joint metal fitting, the above-mentioned The fitting hardware swells. This bulge is connected to the strain gauge attached to the outer surface of the fitting hardware. It can be detected at 20. The strain gauge 22 attached to the inner surface of the two-part hardware is a dummy gauge. This is for calibrating the strain gauge 20 at the same time.

[0008]

【Example】

An embodiment of this invention will be described with reference to FIGS. 1 to 3. Figure 1 is an overall configuration diagram of the first embodiment of the invention, and Figure 2 is the vibration-resistant fuel of the invention. Outline drawing of the oil injection pressure sensor, Figure 3 is a cross section of the vibration-resistant fuel oil injection pressure sensor of the invention It is a diagram. In the figure, 1 is a fuel injection cam, and 2 is a fuel injection pump that injects the fuel. Driven by a cam. Since many other parts of the structure are the same as those of the conventional example, we will not discuss those parts. Light is omitted. (40 is the injection valve) 24 is the fitting hardware and the material is structural steel JIS standard S45C has a cylindrical shape with a hole passing through the center and pipe threads at both ends. It is being A six-sided spanner hook is provided below the upper pipe screw, and the lower side The cross section A-A in Fig. 3(a) is provided with a square cross-sectional constriction. . The center part is carefully finished into a cylindrical shape. This is the X section in FIG. With the above fittings This concludes the explanation of item 24.

[0009] Reference numeral 23 denotes a two-part metal fitting, which is composed of two symmetrical pieces, and has the same cross-sectional shape as the joint metal fitting 24. It fits into the constriction of the rectangle and tightens, and covers the center part of the joint hardware 24 by sandwiching it. . 34 is a steel plate made of JIS standard SS41 and is spot welded to one piece of the two-piece metal fitting. I'm being kicked. 31 is a bolt made of chromium molybdenum steel, and the steel plate 34 is It is fastened to the other piece of the two-part hardware 23. 32 is a bolt that connects the two-part metal fitting 23. Tighten the two pieces together. 20 is a strain gauge pasted on the central part X of the joint hardware 24. It is attached. 21 is a coating and the material is phenolic resin and the strain gauge is It covers 20. The joint hardware 24 is connected to the fuel injection pipe 3 and the fuel injection valve 4a. It is. 25 is a conducting wire connected to the strain gauges 20 and 22 and connected to the two-part metal fitting 23. It is led out through a hole provided in and connected to the amplifier 7. 35 is vibration resistant This is a dynamic fuel oil injection pressure sensor.

0010 Next, the operation of the embodiment will be explained. The fuel to be injected is pushed out to the injection pump 2, and from the fuel injection pipe 3 to the joint metal. Since the flow passes through the through hole in the center of the object 24 to the injection valve 4a, the joint metal object 24 The strain gauge 20 detects this bulge, which swells in response to the injection pressure of fuel passing through the hole. This is processed by an amplifier 7, an A/D converter 8, and a computer 9, and output to an output device 10. can be displayed as injection pressure. The bolt 32 is attached to the two-part metal fitting 23. Tighten the two pieces together at the constriction of the square cross-section of the joint hardware 24, and You can also cover the center of the joint hardware and tighten it with scissors to prevent it from rotating. In addition to preventing it from falling, the rigidity of the joint hardware 24 is increased to make it vibration resistant. strain gauge 20 detects the bulge of the joint hardware 24 in response to the fuel pressure. coaching 21 protects the strain gauge 20. The strain gauge 22 is a dummy gauge and a strain gauge. This is used to calibrate the camera 20, etc. Hardware 23 divided into two with bolt 31 The bolt 31 is made of strong chromium molybdenum steel. Even if the fitting hardware 24 breaks and oil of 1000 kgf/cm spouts out, it can withstand the force. I can do it.

[0011]

[Effect of the idea]

As mentioned above, this idea tightens the two-part metal fittings to increase rigidity and prevent the effects of vibration. Connect the metal fittings obtained between the fuel injection pipes to allow the injected fuel to flow, and the pressure Improved durability and reliability as strain gauges can detect bulges in fittings according to A vibration-resistant fuel injection pressure sensor can be provided.

[Brief explanation of drawings]

[Fig. 1] Overall configuration diagram of the first embodiment of the present invention

[Figure 2] External diagram of the vibration-resistant fuel oil injection pressure sensor of the present invention

[Figure 3] Cross-sectional view of the vibration-resistant fuel oil injection pressure sensor of the present invention

FIG. 4 is a configuration diagram of a conventional example.

[Explanation of symbols]

20 Strain gauge, 21 Coating, 22 Strain gauge, 23 Two-part hardware, 24 Joint hardware, 25
Conductor, 31 volts, 32 volts, 34
Steel plate, 35 Vibration resistant fuel injection pressure sensor.

Claims (1)

[Scope of utility model registration request] 1. A fitting hardware (24) having a cylindrical shape and having a hole passing through along the axis, pipe threads provided at both ends, and a constriction having a square cross section in part; A strain gauge (20) affixed to the outer surface of the central part and coated on the surface, and a two-piece piece that fits into the constriction of a square cross-section of the joint metal fitting and covers and sandwiches the central part of the joint metal fitting. A vibration-resistant fuel injection pressure sensor comprising a metal piece (23) and a strain gauge (22) attached to the inner surface of the two-part metal piece.