JP2005076478A - Delivery pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a delivery pipe for reducing pressure vibration in a fuel supply passage without the need for greatly changing the shape of a housing. <P>SOLUTION: A diaphragm 5 is mounted in the housing 2 to block the fuel supply passage 2a of the delivery pipe 1. The diaphragm 5 consists of a flange portion 5a and a hollow protruded portion 5b protruded to one side of the flange portion 5a. A plug 3 is threaded to the housing 2, whereby the flange portion 5a of the diaphragm 5 is held between the plug 3 and the housing 2 and fixed to the housing 2 via a seal member 4 and an additional seal member 6. In the state that the diaphragm 5 is mounted in the housing 2, a slack space C is formed inside the protruded portion 5b where the diaphragm 5 can slacken. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a delivery pipe that distributes fuel supplied to a fuel supply path to fuel injection valves.

In the fuel supply path of the delivery pipe that distributes the fuel to a plurality of fuel injection valves, high-pressure fuel from the fuel pump is introduced, and the fuel injection valve opens and closes to cause vibration (fluctuation) in the fuel pressure. . In order to prevent the propagation of vibrations to the engine, there has been a conventional technique for reducing the pressure vibration in the fuel supply path, in which the housing of the delivery pipe has a flat triangular cross section (see, for example, Patent Document 1).
JP 2002-295338 A (FIG. 2)

  However, in the above-described conventional technology, it is necessary to change the shape of the housing significantly, and it is necessary to review the layout of peripheral parts in order to avoid interference. In addition, it is necessary to make a mold for forming the outer shape of the housing completely, and there is a problem in terms of manufacturing cost.

  The present invention has been completed based on the above-described circumstances, and an object of the present invention is to provide a delivery pipe that can reduce pressure vibration in the fuel supply passage without significantly changing the housing shape.

  As a means for achieving the above-mentioned object, the invention of claim 1 has a long shape in which a fuel supply passage is provided inside, and a plurality of fuel injection valve attachment portions to which the fuel injection valves are attached are formed on the outer peripheral portion. In a delivery pipe that distributes the fuel supplied to the fuel supply path to the fuel injection valve, the fuel supply path and the outside of the housing are connected so as to close an end of the fuel supply path. A flexible diaphragm is disposed through a sealing member that shuts off, and a cap member is attached to the housing so that a peripheral edge of the diaphragm is sandwiched between the housing and the housing through the sealing member. A delivery pipe having a bending space in which a central portion of the diaphragm can be bent is formed between the diaphragm and the cap member. It was.

  The invention according to claim 2 is characterized in that the diaphragm has a hollow protrusion protruding into the fuel supply path, and the bending space is formed between the inside of the protrusion and the cap member. A delivery pipe according to claim 1 is provided.

  According to a third aspect of the present invention, there is provided a delivery pipe according to the first aspect, wherein a concave portion is formed at a tip portion of the cap member, and the bending space is formed between the concave portion and the diaphragm. .

  According to a fourth aspect of the present invention, a cylindrical member is interposed between the cap member and the diaphragm, and the bending space is a space formed by an inner peripheral hole of the cylindrical member, the cap member, and the diaphragm. The delivery pipe according to claim 1, wherein the delivery pipe is provided.

  According to a fifth aspect of the present invention, an additional seal member is provided between the diaphragm and the cap member so as to block the bending space from the outside of the housing. The delivery pipe according to any one of the above was used.

  According to a sixth aspect of the present invention, the cap member includes a head portion facing the end surface of the housing in a state where the cap member is mounted on the housing, and the cap member is sandwiched and pressed between the end surface of the housing and the head portion. The delivery pipe according to claim 3 or 4, further comprising an additional seal member that blocks the bending space and the outside of the housing.

  According to a seventh aspect of the present invention, the fuel supply path includes an elongate housing having a fuel supply path extending therein and a plurality of fuel injection valve mounting portions to which fuel injection valves are mounted on the outer periphery. In the delivery pipe that distributes the fuel supplied to the fuel injection valve, a pair of seal members that shut off the fuel supply path and the outside of the housing are sealed at both ends so as to close the fuel supply path. And a pair of cap members are attached to both ends of the housing so that the peripheral edge of the diaphragm is sandwiched between the housing and the housing via the seal member, A delivery pipe in which a bending space in which a central portion of the diaphragm can be bent is formed between each of the diaphragms and the cap member. It was.

<Invention of Claim 1>
In the delivery pipe, a flexible diaphragm is disposed through a seal member that shuts off the fuel supply path and the outside of the housing so as to block the end of the fuel supply path, and the peripheral edge of the diaphragm is sealed with the seal member. The cap member is attached to the housing so as to be sandwiched between the housing and the diaphragm, and the cap member is provided with a bending space in which the central portion of the diaphragm can be bent. The pressure vibration in the fuel supply path can be reduced without significantly changing the shape of the housing.

<Invention of Claim 2>
The diaphragm has a hollow protrusion that protrudes into the fuel supply path, and the flexure space is formed between the inside of the protrusion and the cap member, so that the existing size can be reduced without increasing the outer dimension of the housing. A flexible space can be easily formed in the housing.

<Invention of Claim 3>
A recess is formed at the tip of the cap member, and the bending space is formed between the recess and the diaphragm, so that the bending space can be formed without affecting the volume of the existing fuel supply path.

<Invention of Claim 4>
A cylindrical member is interposed between the cap member and the diaphragm, and the bending space is a space formed by the inner peripheral hole of the cylindrical member, the cap member and the diaphragm, so that the cap member and the diaphragm are specially processed. A bending space can be formed without applying.

<Invention of Claim 5>
By providing an additional seal member between the diaphragm and the cap member that shuts off the flex space and the outside of the housing, the air tightness of the flex space can be improved and even if fuel leaks from the diaphragm. It is possible to prevent leakage to the outside of the housing.

<Invention of Claim 6>
The cap member has a head portion that faces the end surface of the housing when mounted on the housing, and is sandwiched between the end surface of the housing and the head portion to block the flex space and the outside of the housing. By interposing the seal member, the airtightness of the bending space can be improved, and even if fuel leaks from the diaphragm, it can be prevented from leaking to the outside of the housing.

<Invention of Claim 7>
In the delivery pipe, a pair of flexible diaphragms are disposed at both ends of the delivery pipe via seal members that shut off the fuel supply path and the outside of the housing so as to close the fuel supply path, and the peripheral edge of the diaphragm is disposed on the delivery pipe. A pair of cap members are attached to both ends of the housing so as to be sandwiched between the housing via the seal member, and the center portion of the diaphragm can bend between each diaphragm and the cap member. By forming the bending space, it is possible to reduce pressure vibration at both ends of the fuel supply path without significantly changing the existing housing shape.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a delivery pipe 1 includes a housing 2 provided with a fuel supply passage 2a having a circular cross section. The housing 2 is formed by, for example, aluminum die casting (casting), has a long shape as shown in FIG. 1, and a cylindrical fuel injection valve in which an engine fuel injection valve IV is attached to the outer peripheral portion in the axial direction. A plurality of attachment portions 2b are formed. Further, a fuel tube (not shown) connected to a fuel pump is attached to an end portion of the housing 2 on the side opposite to the side where the plug 3 is mounted, so that fuel is supplied into the fuel supply path 2a. An inlet 2c to be introduced is formed.

  As shown in FIG. 2, a plug 3 that closes the end of the fuel supply path 2 a is attached to the end of the housing 2. A female screw hole 2d for screwing the plug 3 and a lower hole 2e continuous with the female screw hole 2d are formed at the end of the housing 2 so as to communicate with the fuel supply path 2a (shown in FIG. 2). . The plug 3 has a male screw portion 3a screwed into a female screw hole 2d formed in the housing 2, a head portion 3b provided at the rear portion of the male screw portion 3a, and a small diameter portion formed at the tip of the male screw portion 3a. 3c. The head 3b has a hexagonal shape or a two-sided width so that the plug 3 is held by a tightening tool when the plug 3 is screwed into the female screw hole 2d. The small diameter portion 3c has a smaller diameter than the male screw portion 3a.

  As the seal member 4, for example, a gasket formed in a ring shape with a soft metal such as copper can be used. However, a seal member formed of rubber or a synthetic resin material may be used. The flexible diaphragm 5 is made of a thin metal plate having a relatively high rigidity, and is attached in the housing 2 so as to close the side opposite to the inlet 2c of the fuel supply path 2a. As shown in FIG. 3, the diaphragm 5 includes a circular flat flange portion 5a and a hollow protrusion 5b protruding to one side of the flange portion 5a by being integrally formed with the flange portion 5a. The protrusion 5b is formed in a cylindrical shape as shown in FIG. 3, and its tip is closed like a bag. As with the seal member 4, the additional seal member 6 can use a gasket formed in a ring shape with a soft metal such as copper. For example, the additional seal member 6 is made of rubber or a synthetic resin material. Also good. The additional seal member 6 is interposed between the flange portion 5 a of the diaphragm 5 and the tip portion of the plug 3, and blocks the bending space C from the outside of the housing 2 in a liquid-tight manner.

  When the diaphragm 5 is attached to the housing 2, first, the seal member 4 is inserted into the lower hole 2 e of the housing 2 so as to contact the end surface 2 f of the lower hole 2 e of the housing 2. Next, the diaphragm 5 is inserted into the housing 2 so that the protrusion 5 b is inserted into the inner peripheral hole of the seal member 4. Further, after the additional seal member 6 is placed on the flange portion 5a of the diaphragm 5, the plug 3 is screwed into the female screw hole 2d of the housing 2, whereby the distal end portion of the plug 3 and the end surface 2f of the housing 2 are connected. The peripheral edge of the flange portion 5a of the diaphragm 5 is sandwiched between the seal member 4 and the additional seal member 6 to fix the diaphragm 5 to the housing 2 (shown in FIG. 4).

  As shown in FIG. 2, the diaphragm 5 is mounted on the housing 2, and its protrusion 5 b protrudes into the fuel supply path 2 a. Further, a bending space C of the diaphragm 5 is formed between the protrusion 5 b and the tip of the plug 3. The fuel supply path 2a and the bending space C are liquid-tightly blocked from the outside by the seal member 4 and the additional seal member 6, respectively.

  In the present embodiment, when the fuel discharged by the fuel pump is introduced into the fuel supply path 2a through the inlet 2c, the fuel is distributed to each fuel injection valve IV attached to the fuel injection valve attachment portion 2b. Injected into each cylinder of the engine. When fuel pressure fluctuation (vibration) occurs in the fuel supply path 2a due to the introduction of the fuel pressure into the fuel supply path 2a or the opening / closing operation of the fuel injection valve IV, the pressure fluctuation is applied to the protrusion 5b of the diaphragm 5. As shown by the two-dot chain line in FIG. 2, the protrusion 5b repeatedly bends toward the bending space C due to a change in fuel pressure, and changes the volume in the fuel supply path 2a, thereby changing the fuel supply path 2a. The particularly peak portion of the fuel pressure generated in 2a is cut to absorb the pressure fluctuation.

  The diaphragm 5 is not limited to metal, and is a material such as ceramic or hard resin material that has flexibility and has strength to withstand the fuel pressure in the fuel supply path 2a, and can close the fuel supply path 2a in a liquid-tight manner. Anything can be used. Further, by changing the plate thickness of the diaphragm 5, the rigidity can be changed and the frequency characteristic of the pressure fluctuation to be absorbed can be changed. As a modification of the diaphragm 5 according to the first embodiment, as shown in FIG. 5, a diaphragm 7 having a triangular cylindrical projection 7b integrally with a circular flange portion 7a may be used. Similarly to the diaphragm 5, the diaphragm 7 is closed in a bag shape at the tip of the protrusion 7 b.

  In the present embodiment, a flexible diaphragm 5 is provided via a seal member 4 that shuts off the fuel supply path 2a and the outside of the housing 2 so as to close the end of the fuel supply path 2a. A plug 3 is attached to the housing 2 so that the flange portion 5a of the pin 5 is sandwiched between the flange 5a and the housing 2 via the seal member 4, and the diaphragm 5 can be bent between the diaphragm 5 and the plug 3. By forming the flexible space C, it is possible to reduce pressure vibration in the fuel supply path 2a without significantly changing the existing housing shape. The diaphragm 5 has a hollow protrusion 5b protruding into the fuel supply path 2a, and the flexure space C is formed between the inside of the protrusion 5b and the plug 3, thereby reducing the outer dimension of the housing 2. The bending space C can be easily formed in the existing housing without increasing the size.

  Further, by interposing the additional seal member 6 between the flange portion 5a of the diaphragm 5 and the plug 3 so as to shut off the bending space C and the outside of the housing 2, the airtightness of the bending space C can be improved. Even if fuel leaks from the diaphragm 5, it can be prevented from leaking to the outside of the housing 2.

Second Embodiment
Next, a second embodiment of the present invention will be described based on FIG. 6 with a focus on differences from the first embodiment. In the present embodiment, the plug 9 is screwed into the housing 2 so that the peripheral edge of the flat diaphragm 8 is connected to the front end of the plug 9 and the lower hole of the housing 2 via the seal member 4 and the additional seal member 6. It is clamped between the end surface 2 f of 2 e and fixed to the housing 2. The diaphragm 8 is formed of a relatively high rigidity thin metal plate like the diaphragm 5, and is attached in the housing 2 so as to close the side opposite to the inlet 2c of the fuel supply path 2a. Any material can be used as long as it is flexible and can withstand the fuel pressure in the fuel supply passage 2a and can close the fuel supply passage 2a in a liquid-tight manner, such as ceramic and hard resin material. Things can be used. A concave portion 9a is formed in the distal end portion of the plug 9 by cutting through the inside thereof, whereby a bending space C is formed between the concave portion 9a and the diaphragm 8.

  In this embodiment, when the fuel pressure fluctuates in the fuel supply passage 2a, the pressure fluctuation is transmitted to the diaphragm 8, and the central portion of the diaphragm 8 is repeatedly bent toward the space C due to the fluctuation of the fuel pressure. By changing the volume in the supply passage 2a, particularly the peak portion of the fuel pressure generated in the fuel supply passage 2a is cut, and the pressure fluctuation is absorbed.

  In the present embodiment, the recess 9a is formed at the tip of the plug 9, and the bending space C is formed between the recess 9a and the diaphragm 8, so that the volume of the existing fuel supply path 2a is not affected. The bending space C can be formed.

<Third Embodiment>
FIG. 7 shows a third embodiment of the present invention. In the present embodiment, by screwing the plug 9 into the housing 2, the peripheral portion of the flat diaphragm 8 is connected to the tip end portion of the plug 9 and the end face 2 f of the lower hole 2 e of the housing 2 via the seal member 4. And is fixed to the housing 2. Similar to the second embodiment, a concave portion 9a is formed in the tip portion of the plug 9 by cutting through the inside of the plug 9, and a bending space C is formed between the concave portion 9a and the diaphragm 8.

  In the present embodiment, the additional seal member 10 is interposed between the head portion 9b of the plug 9 and the end surface 2g of the housing 2 facing the head portion 9b. The additional seal member 10 has its inner peripheral hole inserted through the male threaded portion 9c of the plug 9 and then screwed into the housing 2 to thereby connect the head 9b of the plug 9 and the end surface 2g of the housing 2 to each other. The pressure is sandwiched between them, and the space between the bending space C and the outside of the housing 2 is liquid-tightly blocked. As in the case of the additional seal member 6, the additional seal member 10 may be a gasket formed of a soft metal such as copper in a ring shape. However, the plug 9 is screwed into the housing 2 so that the seal member 4 In order to achieve both sealing properties, it is desirable to use the additional sealing member 10 made of a highly compressible material such as rubber or synthetic resin material. Since the function of the diaphragm 8 according to the present embodiment is the same as that of the second embodiment, the description thereof is omitted.

  In the present embodiment, the additional seal member 10 is interposed between the end surface 2g of the housing 2 and the head portion 9b of the plug 9 so as to block the bending space C and the outside of the housing 2 from each other. As a result, the airtightness of the bending space C can be improved, and even if fuel leaks from the diaphragm 8, it can be prevented from leaking to the outside of the housing 2.

<Fourth embodiment>
FIG. 8 shows a fourth embodiment of the present invention. In the present embodiment, a cylindrical member 11 having an inner peripheral hole 11 a penetrating in the axial direction is interposed between the tip end portion of the plug 12 and the flat diaphragm 8, and the plug 12 is screwed into the housing 2. Thus, the peripheral edge of the flat diaphragm 8 is sandwiched between the cylindrical member 11 and the end face 2 f of the lower hole 2 e of the housing 2 via the seal member 4, and is fixed to the housing 2. As described above, since the inner peripheral hole 11 a is formed in the cylindrical member 11, the bending space C is formed by the inner peripheral hole 11 a, the distal end portion of the plug 12, and the diaphragm 8. Further, an additional seal member 10 is interposed between the head portion 12b of the plug 12 and the end surface 2g of the housing 2 as in the third embodiment. Since the function of the diaphragm 8 according to the present embodiment is the same as that of the second embodiment, the description thereof is omitted.

  In the present embodiment, a cylindrical member 11 is interposed between the plug 12 and the diaphragm 8, and the bending space C is a space formed by the inner peripheral hole 11 a of the cylindrical member 11, the plug 12 and the diaphragm 8. As a result, the bending space C can be formed without special processing of the plug 12 and the diaphragm 8.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described with reference to FIG. In the delivery pipe 21 according to the present embodiment, the diaphragm 5 in the first embodiment is attached to both ends thereof so as to close the fuel supply path 22a of the housing 22. Therefore, the inlet 22 c is formed from the central portion of the housing 22. The mounting method of the diaphragm 5 to the housing 22 and other configurations are the same as in the first embodiment. Moreover, since the function of the diaphragm 5 according to the present embodiment is the same as that of the first embodiment, the description thereof is omitted.

  In the present embodiment, by attaching the pair of diaphragms 5 to both ends of the housing 22, pressure vibrations can be reduced at both ends of the fuel supply path 22a without significantly changing the existing housing shape. .

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention. Various modifications can be made without departing from the scope of the invention.
(1) Instead of a screw-in type plug, a cap member that is caulked and fixed to the end of the housing, or one that is fixed by welding or welding may be used.
(2) The housing may not be formed by casting aluminum, but may be formed by processing cast iron or steel.
(3) In order to apply the delivery pipe according to the present invention to a multi-cylinder engine other than the four-cylinder engine, the number of the fuel injection valve attachment portions may be a number other than four.

It is sectional drawing of the delivery pipe by 1st Embodiment. It is a principal part enlarged view of the delivery pipe shown in FIG. It is a side view of the diaphragm shown in FIG. It is an exploded view of the edge part structure of the delivery pipe shown in FIG. It is a side view of the diaphragm by the modification of 1st Embodiment. It is a principal part enlarged view of the delivery pipe by 2nd Embodiment. It is a principal part enlarged view of the delivery pipe by 3rd Embodiment. It is a principal part enlarged view of the delivery pipe by 4th Embodiment. It is sectional drawing of the delivery pipe by 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 21 ... Delivery pipe 2, 22 ... Housing 2a, 22a ... Fuel supply path 2b, 22b ... Fuel injection valve attaching part 2g ... End surface of housing 3, 9, 12 ... Plug 4 ... Seal member 5, 7, 8 ... Diaphragm 5a, 7a ... Flange 5b, 7b ... Projection 6, 10 ... Additional seal member 9a ... Recess 9b, 12b ... Head 11 ... Cylindrical member 11a ... Inner peripheral hole IV ... Fuel injection valve C ... Deflection space

Claims (7)

An elongate housing having a fuel supply passage therein and a plurality of fuel injection valve attachment portions on which fuel injection valves are attached to an outer peripheral portion is provided, and the fuel supplied to the fuel supply passage is injected into the fuel injection passage In the delivery pipe that distributes to the valve,
A flexible diaphragm is disposed via a seal member that shuts off the fuel supply path and the outside of the housing so as to close the end of the fuel supply path, and the peripheral edge of the diaphragm is disposed on the seal member A cap member is attached to the housing so as to be sandwiched between the housing and the diaphragm, and a bending space in which a central portion of the diaphragm can be bent is formed between the diaphragm and the cap member. Delivery pipe characterized by that. 2. The delivery according to claim 1, wherein the diaphragm has a hollow protrusion protruding into the fuel supply path, and the bending space is formed between the inside of the protrusion and the cap member. pipe. The delivery pipe according to claim 1, wherein a concave portion is formed at a distal end portion of the cap member, and the bending space is formed between the concave portion and the diaphragm. A cylindrical member is interposed between the cap member and the diaphragm, and the bending space is a space formed by an inner peripheral hole of the cylindrical member, the cap member, and the diaphragm. Item 1. The delivery pipe according to Item 1. The delivery pipe according to any one of claims 1 to 3, wherein an additional seal member is provided between the diaphragm and the cap member to block the bending space and the outside of the housing. . The cap member includes a head portion that faces the end surface of the housing in a state of being mounted on the housing, and is sandwiched between both the end surface of the housing and the head portion so that the bending space and the housing The delivery pipe according to claim 3 or 4, further comprising an additional seal member that shuts off the outside. A fuel supply passage extending inward and having a long housing formed with a plurality of fuel injection valve attachment portions to which fuel injection valves are attached on an outer peripheral portion, the fuel supplied to the fuel supply passage being In the delivery pipe that distributes to the fuel injection valve,
A pair of flexible diaphragms are arranged at both ends of the fuel supply path via seal members that shut off the fuel supply path and the outside of the housing. A pair of cap members are attached to both ends of the housing so as to be sandwiched between the housing via the seal member, and between each of the diaphragms and the cap member, A delivery pipe characterized in that a bending space in which a central portion can be bent is formed.

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