JPH06213088A - Pressure regulating valve - Google Patents

Abstract

PURPOSE:To reduce the total cost in lowering the cost of production and improve the quality by raising a working property for setting an O-ring and vice versa and its sealability, getting rid of any nonconformity such as a flaw or a break due to this O-ring setting operation, and simplifying the form of constituent parts in a installing part, in a method of attaching a fuel pressure regulating valve direct to an engine. CONSTITUTION:This pressure regulating valve is in structure made up of adopting a three-point sealing process as in the following procedures that a cylindrical tube is used for a fuel inflow port member 26 or outflow port member on the side of this valve, making it project from a bracket 9 and inserting an O-ring 25 into the circumference, and other hand, a fuel feeding path or return path at the engine side is indwelt, a flange surface 21 fitted with a case 15 of this valve is integrally formed there and an orthogonal cross angle part with a hole part is made into a conical form, and then this conical part is pressed under pressure to a triangular groove part, where the O-ring 25 is conically formed at the time of installing this valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure regulating valve in a fuel injection type fuel supply device.

[0002]

2. Description of the Related Art FIGS. 2 and 6 show a sectional structure of a method of mounting a pressure regulating valve, which has been most widely and conventionally used, on an engine. In the case of FIG. 2, a concave groove for attaching an O-ring is formed in the protruding boss portion of the fuel inlet on the pressure regulating valve side, and in the flange portion of the engine side in FIG. 6 to prevent fuel leakage. Although the groove-type sealing method was used, in the method of FIG. 2, the O-ring is inserted into the protruding boss portion of the pressure regulating valve and then pushed into the fuel pipe hole of the engine. In the assembling work of inserting into the groove of the O, further handling in the middle of distribution after that, and further in the work of attaching to the fuel connecting hole on the engine side, the outer peripheral part of the O-ring is pressed and inserted, so scratches and cuts are always The insertion work was also difficult. In the case of FIG. 6, fuel leaks due to flatness of the joint surfaces of the flanges on the pressure regulating valve side and the engine side, scratches during processing and handling, and the difficulty of machining concave grooves for mounting O-rings on the flange surface. However, there is a problem in the assemblability such as the O-ring falling off when the pressure regulating valve is attached to the engine side, and these are exactly the same in the market, which makes service workability such as maintenance and inspection extremely difficult. Both of these structures are easily deformed or damaged at the time when the O-ring is inserted or tightened, and it is difficult for the operator to recognize the structure, which is a major factor of a serious accident such as a fire due to fuel leakage later. On the other hand, in terms of manufacturing, groove processing and securing the flat surface of the flange,
There were many chronic problems in the insertion and insertion of the O-ring, distribution and handling, and the management was difficult and the cost was high (Shokai Sho 60-159878, Shokai 61-62274, Japanese Patent Laid-Open No. 61274).
-145350, JP-A-62-658, JP-A-62-131963,
JP-A-62-162767, JP-A-1-92572, JP-A-4-171
No. 69).

[0003]

With respect to the structure of the mounting portion of the pressure regulating valve to the engine, a simple structure is adopted to incorporate an O-ring for preventing fuel leakage, the pressure regulating valve is mounted to the engine, and is detached by maintenance and inspection in the market. The workability is improved and the manufacturing cost of the pressure regulating valve and the mounting part structure on the engine side is provided at the same time, and at the same time, there is no cause of serious accidents such as fuel leakage due to scratches or damage to the O-ring, and assembly failure. The purpose is to

[0004]

Means for Solving the Problems A fuel connection between a pressure regulating valve and an engine side relates to a direct mounting method other than mounting by a pipe such as a rubber pipe. A cylindrical convex portion is provided at a part of a fuel inlet or outlet of the pressure regulating valve. A pipe is formed to project and an O-ring is inserted and incorporated in the outer peripheral portion, and the convex projection is inserted into a fuel supply passage hole to the pressure regulating valve on the engine side, or an exhaust fuel conduit hole from the pressure regulating valve,
A pressure regulating valve according to a structure in which an end face corner portion of each of the holes is formed in a conical shape, an O-ring is sandwiched between triangular grooves formed by the conical portion and the pressure regulating valve flange, and a fuel leakage prevention seal is provided.

[0005]

FIG. 1 shows a fuel supply system for a fuel injection type internal combustion engine. Fuel is pressure-fed from a fuel tank 1 through a fuel filter 3 by a fuel pump 2 into a fuel feed pipe 4 and branched midway, and the fuel is electronically controlled by a signal from an electromagnetic fuel injection valve 5 so that the fuel is drawn into an intake pipe 6 of an engine. Is injected into. The fuel supply capacity of the fuel pump 2 is generally more than double the flow rate and pressure required by the engine. Therefore, the surplus fuel is further pressure-fed through the feed pipe 4 and is sent to the fuel pressure regulating valve 7 to keep the fuel pressure of the feed pipe 4 constant, while the surplus fuel is fed to the fuel tank 1 through the return pipe 8. The circulation system is returned. FIG. 2 shows a sectional structure of the fuel pressure regulating valve 7. The pressure regulating valve 7 has an air chamber body 1 having a spring 10 and a cover 11 on one side through a diaphragm 9.
A valve 1 for integrally driving the diaphragm 9 on the second side and the second side.
3, a valve seat 14, a bracket 19 for directly mounting the pressure regulating valve 7 on the engine, a fuel inlet member 16 and an outlet member 17 for returning excess fuel to the fuel tank 1 and a case 15.
The fuel chamber body 18 constituted by is formed by combining both chamber bodies. Further, in the case where the pressure regulating valve 7 is directly mounted on the engine side, which is the object of the present invention, the fuel feed pipe 4 to the pressure regulating valve 7 on the engine side is attached.
It is most widely used to have the flange 21 shown in FIG. 3, and the pressure regulating valve 7 and the feed pipe 4 are joined by the bracket 19 and the flange 21, and the fuel leakage prevention seal is adjusted. A concave groove is provided on the outer circumference of the inlet member 16 of the pressure valve 7, the O-ring 20 is inserted and incorporated therein, and then the outer circumference of the O-ring 20 is inserted into the fuel passage of the feed pipe 4 while being pressed.
At 2, the bracket 19 and the flange 21 are clamped and fixed. The fuel passes through the feeding pipe 4 and the inflow port member 16 of the pressure regulating valve 7.
And is introduced into the case 15. Since the pressure of the introduced fuel is higher than the constant required pressure required for the injection valve 5, the fuel pushes up the diaphragm 9 and compresses the spring 10. At this time, the valve 13 is actuated to move away from the valve seat 14 to be in the open state, and the introduced fuel is returned to the fuel tank 1 through the outlet member 17 and the return pipe 8. At the same time when the valve is opened, the pressure in the fuel chamber body 18 is lowered and the spring 10 pushes back the diaphragm 9 again to bring the valve 13 into contact with the valve seat 14 to close the valve, so that the fuel pressure again increases. By repeating this, the inside of the fuel chamber body 18 and the inside of the feed pipe 4 are maintained at substantially the fuel pressure required by the injection valve 5, and the control of the return pipe for the surplus fuel is simultaneously performed. FIG. 3 shows an example of a mounting flange surface on the engine side where the pressure regulating valve 7 is mounted, and generally has the same shape as the bracket 19 on the pressure regulating valve 7 side. For this reason, the surface roughness of the joint surface between the two mounting surface portions may be rough or medium, even in the case of die casting and as-casting, but flatness is generally required to be about 0.2 or less. FIG. 4 is a cross-sectional view when the pressure regulating valve 7 is mounted and attached to the feed pipe 4 on the engine side, and is a sectional view taken along the line BB of FIG. The O-ring 20 is sandwiched between the hole of the feeding pipe 4 and the groove of the inflow port member 16 of the pressure regulating valve 7 and compressed, and a leakproof seal is provided at two points of the hole and the groove. FIG. 5 shows a detailed cross section of this mounting and mounting portion. This type of structure is the most widely used, but since the inner diameter C of the O-ring 20 is smaller than the diameter A of the groove bottom of the inlet member 16 of the pressure regulating valve 7, the O-ring 20 is previously formed in the groove portion. Need to insert. At this time, the O-ring 20 is expanded by a jig or the like, pulled from the outer diameter B of the inflow port member 16, and inserted into the groove along the outer diameter B. Therefore, the O-ring 20 is often damaged or cut during the insertion work, and management such as judgment and confirmation of the degree of damage is difficult. Further, after inserting the O-ring 20 into the groove, when mounting it on the feed pipe 4 on the engine side, the O-ring is inserted into the hole diameter D part which is slightly larger than the outer diameter of the inlet member 16 of the pressure regulating valve 7.
The ring 20 is inserted while applying a lubricant or the like on its outer periphery and sliding. In this type of structure, the hole D of the O-ring 20
When inserting into the flange, the O-ring 20 is often broken at the corner intersecting the entrance with the flange 21 surface, so a conical processing part with an angle θ depth H is always formed at the entrance as an insertion guide.
Furthermore, since a cutting loss occurs at the intersection with the hole D, a smooth R-shaped chamfering is also performed. Of course, cone part θ and H, hole D
Since the O-ring 20 is pressed and slid while being inserted and incorporated into the surface of the portion, surface roughening of a high level is required. However, even if such troublesome processing and parts management are performed, the cutting failure of the O-ring 20 due to manual assembly work such as twisting at the time of insertion still remains. As a matter of course, even in the desorption service work such as maintenance and inspection in the market, it is extremely difficult to thoroughly control the same as in the production process, and the potential factor of a serious accident cannot be eliminated.
6, the structure and function of the pressure regulating valve 7 are the same as those of FIG. 2, but the return passage of the surplus fuel to the engine side is different from that of FIG. 2, and the feed pipe line 4 and the return pipe line 8 from the engine side are integrated. The cross section of the embodiment of the method of directly mounting the pressure regulating valve 7 to the engine in the case of the composite type fuel pipe body molded in FIG. In this case, the flange surface 24 of the composite fuel pipe on the engine side has the shape shown in FIG.
The shape is almost the same, and it is screwed in the same manner as in FIG. In FIG. 8, an attachment groove for an O-ring 20 having a width G, a depth H, and a diameter K is provided around the holes of the feed pipe 4 and the return pipe 8 on the surface of the flange 24, and the O-rings are provided in the two grooves. 20 is inserted, the bracket 19 on the pressure regulating valve 7 side is brought into contact with the O-ring 20, and the O-ring 20 is crushed to provide a fuel leakage prevention seal at two positions on the bracket 19 surface and the groove bottom surface. In this case, it is difficult to machine and manage the surface of the bracket 19 on the pressure regulating valve 7 side and the groove bottom surface of the flange 24 on the engine side, especially the surface roughness, and since the bracket 19 is flat, it is necessary to machine or assemble parts. When the flange 24 is grooved, the groove width G is generally small and it is almost impossible to move the blade, and it is difficult to perform high-level advanced finishing. It is impractical to expect the groove part by as-casting such as die-casting because of the pinholes and poor flow of molten metal, etc. to meet the required specifications as an important safety component. Of course, in the case of FIG.
The flatness of the flat surfaces of the two contact surface members has to be made more strict than in the case of FIG. 2 described above, which is considerably difficult in terms of manufacturing method and management. Further, in the case of FIG. 6, the O-ring 20 is attached to the flange 2
When the bracket 19 of the pressure regulating valve 7 is mounted by pushing it into the groove of No. 4, the flange 24 surface is often vertical in an actual engine, and the O-ring 20 drops, which makes it difficult to assemble and the defective product is defective. There is a high possibility that a serious accident of fuel leakage will occur due to the above. As described above, there are many problems in the case where the conventional widely and commonly used pressure regulating valve 7 shown in FIGS. 3 and 6 is directly attached to the engine, and the manufacturing cost of the pressure regulating valve required in the market is large. Is not cheap,
Further, it is necessary to indirectly handle with caution when distributing or attaching / detaching in the market, but it is quite difficult to be thorough. In order to solve the above-mentioned drawbacks such as the difficulty of work and management, the present invention makes it easy to assemble the O-ring 20 so that it does not get scratched, and the processing of each part is of a moderate level and requires a small amount of processing to simplify the mounting method. It is a low-priced and reliable method of mounting a pressure regulating valve that can be handled and removed.

[0006]

【Example】

(1) First Embodiment FIG. 9 shows an embodiment in which the drawbacks of the conventional case of FIG. 2 are solved.
The details are shown in 0. The difference between the present invention and the conventional product is that the fuel inlet member 26 is made of a tubular material, and a stepped portion having a diameter L is attached to a part of the outer diameter of the fuel inlet member 26. The stepped portion is inserted into the bracket 19 and the case 15 and fixed by copper brazing or the like. On the other hand, the outer diameter B portion is ground as a tubular material or is slightly centerless or the like, and is ground, and an O-ring 20 is simply inserted into this portion. The feeding pipe 4 is provided on the flange 21.
The diameter D of the hole is made slightly larger than the diameter B of the inlet member 26 of the pressure regulating valve 7, and the corner portion intersecting the hole D and the surface of the flange 21 is processed or formed into a conical shape having an angle θ and a depth W. After the pressure-regulating valve 7 is attached to the engine, the O-ring 20 compresses the conical triangular groove portion in a narrow space to seal the O-ring 20 at three points. Manufacturing cost is low because the conventional concave groove processing is eliminated in the outer diameter portion of the pressure regulating valve 7 side inlet member 26, and the surface of the outer diameter portion B can be sufficiently used even as a bare pipe. As described above, the sealing property is further increased with a slight processing. It is easier to insert the O-ring 20 into the diameter B of the straight cylindrical portion than in the case of pressing into the conventional groove type, and in the case of this type of sealing method, the diameter B of the O-ring 20 is
Since the tightening margin for the O-ring 20 is small, the work of assembling the O-ring 20 is extremely easy, and there is no damage or breakage, and the O-ring 20 is pushed in until it hits the surface of the bracket 19, and becomes the sealing position in that position. Therefore, the length dimension E of the inlet member 26 can be shortened by about 50% as compared with the conventional one, and since the mounting portion of the O-ring 20 is a corner portion, it is difficult for the outer peripheral portion of the inlet member 26 to be damaged. Outer diameter B
It is easy to control the quality such as dimensions and scratches. On the other hand, the angle θ and the depth W of the conical portion on the side of the feed pipe 4 on the engine side can be secured sufficiently by machining or die casting such as die casting, and the passage diameter D serves as a mounting guide for the outer diameter B of the inlet member 26. It is slightly larger than B, which is a loose fit, and plays a sufficient role in machining or casting, and the conical surface is difficult to attach because the scratches after processing or molding due to handling etc. are concave, and the conical surface is the only conical surface. Sufficient and easy to inspect and manage scratches and pinholes, it is generally inexpensive and can greatly solve the problems of conventional manufacturing, distribution and service work.

(2) Second Embodiment FIG. 11 shows an embodiment in which the defect of the conventional FIG. 6 is solved.
The details are shown in. In the present embodiment, the fuel inlet port and the return port portion of the pressure regulating valve 7 are on the same plane, and the fuel feed pipe 4 and the return pipe 8 for the engine side are integrally formed as a composite fuel pipe portion. In the present invention, the pressure regulating valve 7 is attached according to the first method described above.
In the same manner as in FIGS. 9 and 10, the inlet member 27 and the outlet member 27 are newly newly fixed to the conventional bracket 19 and the O-ring is conventionally provided on the flange 24 on the engine side. Grooving is abolished and the angle of intersection between the surface of the flange 24, the fuel hole, and 8 is θ, as in the case of FIG.
The same effect as in the first embodiment can be obtained by forming a conical shape having a depth W. (3) Third Embodiment FIG. 13 shows an embodiment in which the case 15 of the pressure regulating valve 7 is integrated with the conventional inlet member 16 by a molding method such as a die casting method or a plastics method. Since the inlet member 26 and the bracket 19 can be integrally formed with the case 15, the number of parts and the assembling process can be reduced, and the brazing, leak test, and rust-proofing processes can be eliminated, and the cost can be significantly reduced. However, there are many advantages of integration, such as improved productivity, elimination of defective products, and provision of inexpensive, high-quality pressure regulating valves.

[0008]

The pressure regulating valve is directly attached to the engine, and the fuel connecting portion of at least the fuel inflow passage to the pressure regulating valve or the return passage from the pressure regulating valve to the fuel tank is connected by a hose pipe made of rubber or metal. In the case of the direct mounting type, the usage of the O-ring has been improved with respect to the mounting part between the pressure regulating valve and the engine body, and the conventional two-point seal for inserting a concave groove is changed to a three-point sealing method with a triangular groove to increase the sealing point. The machining cost has been improved by eliminating the concave groove processing. The insertability of the O-ring into the pressure regulator valve inlet or outlet member and the easy installation work on the engine facilitate maintenance and inspection in the market. It is possible to prevent the O-ring from being damaged or cut even during the detaching work, and to provide an inexpensive total cost and quality improvement.

[Brief description of drawings]

FIG. 1 is a system diagram of a fuel supply device for a fuel injection type internal combustion engine.

FIG. 2 is a cross section of a conventional mounting example in which the fuel inlet port side of the fuel pressure regulating valve is directly connected to the engine side and mounted.

3 is a view of the engine-side flange surface of FIG. 2 taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

5 is an exploded explanatory view of a mounting portion on the pressure regulating valve side and FIG. 5B on the engine side in the partial details of FIG.

FIG. 6 is a cross-sectional view of a conventional example in which the fuel inlet port and the fuel outlet port of the pressure regulating valve are in the same direction, and both fuel passages are directly connected to the engine.

FIG. 7 is a view showing a flange for mounting the pressure regulating valve on the engine side as viewed from CC of FIG.

8 is a sectional view of the O-ring groove of FIG.

FIG. 9 is a diagram showing an embodiment of the present invention in the case of FIG.

FIG. 10 is a diagram showing an embodiment of the present invention.

11 is a diagram showing an embodiment of the present invention in FIG.

FIG. 12 is a diagram showing an embodiment of the present invention.

13 is a view showing an embodiment in which the case, the inlet member and the bracket are integrated in the embodiment of the present invention shown in FIG.

FIG. 14 is a view showing the outer appearance of the flange surface of FIG.

[Explanation of symbols]

1 ... Fuel tank, 2 ... Fuel pump, 3 ... Fuel filter,
4 ... Fuel feeding pipe, 5 ... Fuel injection valve, 6 ... Engine intake pipe,
7 ... Fuel pressure regulating valve, 8 ... Fuel return pipe, 9 ... Diaphragm,
10 ... Spring, 11 ... Cover, 12 ... Air chamber body, 1
3 ... Valve, 14 ... Valve seat, 15 ... Case, 16 ... Fuel inlet member, 17 ... Fuel return outlet member, 18 ... Fuel chamber body, 19 ... Bracket, 20 ... O-ring, 21 ... Engine side Flange of pressure regulator mounting part, 22 ... Tightening screw, 2
3 ... Fuel return / outflow member, 24 ... Flange of pressure regulating valve mounting portion on engine side, 25 ... O-ring, 26, 27 ... Fuel inlet / outlet member, 28 ... Case, flange and inlet member integrally formed The cross section of the case body.

Claims (3)

[Claims] 1. A fuel injection type fuel supply system for an internal combustion engine, comprising a diaphragm, an air chamber body side having a spring and a cover on one side, a valve and a valve seat on the other side, and a fuel inflow section and a case supporting them. A fuel pressure regulating valve having a structure combined with the fuel chamber body side, which is related to the fuel leakage prevention structure of the fuel inflow part or the outflow part and the attachment to the partner engine side. A flange for attachment is integrally formed, and a cylindrical tubular boss portion that forms a fuel inlet or fuel outlet passage that penetrates the flange and the case is formed to project at approximately the center of the flange, and an O-ring is formed on the outer periphery of the boss. On the other hand, the corner of the fuel connecting surface hole with the pressure regulating valve on the engine side is formed into a conical shape, and the protruding boss of the pressure regulating valve is mounted so as to fit into the fuel connecting hole on the engine side. Ring is the fuel Semmen'ana conical portion and said flange and projecting pressure regulating valve, characterized by comprising established a seal fuel in three contact surfaces being crenellated a triangular groove by forming a triangular boss. 2. A pressure regulating valve according to claim 1, wherein the protruding boss material at the fuel inflow or outflow portion of the pressure regulating valve is formed by simply cutting a pipe material and welded and fixed to a bracket and a case. 3. A pressure regulating valve according to claim 1, wherein a protruding boss member at a fuel inflow or outflow portion of the pressure regulating valve, a case and a bracket are integrally formed.