JP4380724B2 - Damper mechanism and high-pressure fuel supply pump - Google Patents

Description

  The present invention relates to a damper mechanism that reduces fuel pressure pulsation of a high-pressure fuel supply pump that supplies pressurized fuel to a fuel injection valve of an internal combustion engine, and a high-pressure fuel supply pump including such a damper mechanism.

  As a conventional high-pressure fuel supply pump having this kind of damper mechanism or damper mechanism, a single metal diaphragm damper and a single metal diaphragm damper for fixing the outer periphery of the single metal diaphragm to the storage container by welding are provided. Also known are high-pressure fuel supply pumps (see JP 2000-193186 A and JP 3180948 A).

JP 2000-193186 A Japanese Patent No. 3180948

  In the prior art described above, since a single metal diaphragm is used, it is necessary to increase the diameter of the metal diaphragm in order to sufficiently reduce pressure pulsation. Also, in order to reduce the fuel pressure pulsation without increasing the diameter, it may be possible to use two single metal diaphragm dampers, but a large space is required to fix the outer periphery to the storage container by welding, There is a problem that the damper mechanism or the high-pressure fuel supply pump becomes large.

  An object of the present invention is to supply a small damper mechanism having a high effect of reducing fuel pressure pulsation or a small high-pressure fuel supply pump having a damper mechanism having a high effect of reducing fuel pressure pulsation.

In order to achieve the above object, the present invention provides two sets of metal diaphragm assemblies (also referred to as two- plate metal diaphragm dampers) in which the entire circumferences of two metal diaphragms are welded, and the two sets of metal diaphragm dampers. It was comprised so that it might be clamped by a pressing member in the perimeter inside a part from this welding part , or a part, and it may fix to a storage container part.

As a result, the two metal diaphragm assemblies (also referred to as two-metal diaphragm dampers) reduce the pressure pulsation of the low-pressure fuel, so that the fuel can be supplied to the fuel injection valve with a stable fuel pressure.

  An embodiment of the present invention will be described below with reference to the drawings.

Example 1
FIG. 1 is a longitudinal sectional view showing the entire high-pressure fuel supply pump in which the present invention is implemented. FIG. 2 is an overall system diagram of a fuel supply system for an internal combustion engine, and shows a high-pressure fuel supply system used in a direct injection internal combustion engine.

A pump body (also referred to as a pump body) 1 has a suction joint 10 that forms a fuel suction port and a discharge joint 11 that forms a fuel discharge port fixed by screwing. A pressurizing chamber 12 for pressurizing the fuel is formed in the middle.

  A suction valve 5 is provided at the inlet of the pressurizing chamber 12, and a discharge valve 6 is provided at the discharge joint 11. The suction valve 5 and the discharge valve 6 are urged by springs 5a and 6a to close the suction port and the discharge port of the pressurizing chamber 12, respectively, and constitute a so-called check valve that restricts the flow direction of fuel. .

  The pressurizing chamber 12 includes a pump chamber 12a through which the tip of the plunger 2 that is a pressurizing member enters and exits, a suction hole 5b that communicates with the suction valve 5, and a discharge hole 6b that communicates with the discharge valve 6. The pressurizing chamber is formed in the pump body 1 by die casting and cutting.

In the suction chamber 10 a, a solenoid 200 is held by the pump body 1, and an engaging member 201 and a spring 202 are disposed on the solenoid 200. When the solenoid 200 is OFF, the engaging member 201 is biased by a spring 202 in a direction to open the suction valve 5. Since the biasing force of the spring 202 is larger than the biasing force of the suction valve spring 5a, when the solenoid 200 is OFF, the suction valve 5 is in an open state as shown in FIG. The fuel is led from the tank 50 to the fuel inlet of the pump body 1 by the low-pressure pump 51, adjusted to a constant pressure by the pressure regulator 52. After that, the pump body 1 is pressurized and is pumped from the fuel discharge port to the common rail 53. An injector 54, a relief valve 55, and a pressure sensor 56 are attached to the common rail 53. The injectors 54 are installed in accordance with the number of cylinders of the engine, and an engine control unit (ECU)
Inject with 40 signal. The relief valve 55 opens when the pressure in the common rail 53 exceeds a predetermined value, and prevents damage to the piping system.

  A lifter 3 provided at the lower end of the plunger 2 is pressed against a cam 7 by a spring 4. The plunger 2 is slidably held in the cylinder 20 and reciprocates by the cam 100 rotated by an engine cam shaft or the like to change the volume in the pressurizing chamber 12.

  The outer periphery of the cylinder 20 is held by a holder 21 and is fixed to the pump body 1 by screwing a screw threaded on the outer periphery of the holder 21 into a screw threaded on the pump body 1.

  The present embodiment is characterized in that the cylinder 20 merely functions as a sliding holding member of the plunger 2 and does not include a pressurizing chamber. As a result, the cylinder formed of a hard material that is difficult to process can be made into a simple shape, and there is an effect that the seal member is required only at one place of the metal seal 70 provided between the pump body and the cylinder.

  Also, the lower end of the cylinder 20 in the figure is sealed with a plunger seal 30 to prevent gasoline (fuel) blow-by from leaking to the outside (cam 7 side). At the same time, lubricating oil (which may be engine oil) for lubricating the sliding portion is prevented from leaking into the pressurizing chamber.

  The outer periphery of the plunger seal 30 is held by the inner periphery of the lower end of the holder 21.

  When the suction valve 5 is closed during the compression process of the plunger 2, the pressure in the pressurizing chamber 12 rises, whereby the discharge valve 6 is automatically opened and the fuel is pumped to the common rail 53.

  The suction valve 5 is automatically opened when the pressure in the pressurizing chamber 12 becomes lower than the fuel inlet, but the closing is determined by the operation of the solenoid 200.

  When the solenoid 200 is kept in the ON (energized) state, an electromagnetic force greater than the urging force of the spring 202 is generated, and the engaging member 201 is pulled toward the solenoid 200, so that the engaging member 201 and the suction valve 5 are separated. The In this state, the intake valve 5 is an automatic valve that opens and closes in synchronization with the reciprocating motion of the plunger 2. Therefore, during the compression process, the suction valve 5 is closed, and the fuel corresponding to the volume reduction of the pressurizing chamber 12 pushes the discharge valve 6 and is pumped to the common rail 53.

  On the other hand, when the solenoid 200 is kept OFF (non-energized), the engaging member 201 is engaged with the intake valve 5 by the urging force of the spring 202, and the intake valve 5 is held open. Accordingly, even during the compression process, the pressure in the pressurizing chamber 12 is maintained at a low pressure that is substantially equal to that of the fuel introduction port, so that the discharge valve 6 cannot be opened, and the volume reduction of the pressurizing chamber 12 is reduced. The fuel is returned to the fuel inlet side through the intake valve 5.

  Further, if the solenoid 200 is turned on during the compression process, the fuel is fed to the common rail 53 from this time. In addition, once the pressure feeding is started, the pressure in the pressurizing chamber 12 is increased. Thereafter, even if the solenoid 200 is turned off, the suction valve 5 is maintained in the closed state, and the suction process is automatically performed in synchronization with the start. Open the valve.

  Therefore, as the plunger 2 reciprocates, the fuel is sucked from the fuel suction joint 10 into the pressurizing chamber 12, discharged from the pressurizing chamber 12 to the common rail 53, and returned from the pressurizing chamber 12 to the fuel suction passage. One process is repeated, and fuel pressure pulsation occurs on the low pressure side.

  Next, a mechanism for reducing fuel pressure pulsation will be described with reference to FIG. FIG. 3 shows an enlarged view of a mechanism for reducing fuel pressure pulsation.

  The double metal diaphragm damper 80 is configured by bonding two diaphragms 80a and 80b and enclosing a gas 80c therein. The two-metal diaphragm damper 80 is a pressure receiving element that exhibits a pulsation damping function by changing the volume according to a change in pressure from the outside. A thin circular basin-type diaphragm is used, and the two diaphragms are connected coaxially and in a direction in which the concave sides face each other, and gas 80c is formed in the internal space formed between the two diaphragms. Enclosed and configured. The diaphragms 80a and 80b are formed with concentric pleats so that they are easily elastically deformed with respect to a pressure change, and the cross section has a corrugated shape. The two diaphragms 80a and 80b are joined by welding the outer circumferences over the entire circumference, and the internal gas 80c is prevented from leaking by the welding.

  A gas 80c having a pressure equal to or higher than atmospheric pressure is sealed in the internal space. The pressure of the internal gas 80c can be arbitrarily set during manufacturing according to the pressure of the target fluid. The gas to be sealed is, for example, a mixed gas of argon gas and helium gas. Helium is sensitive to leakage from the weld and argon is difficult to leak. Therefore, if there is a leak in the welded portion, it can be easily detected, and the gas 80c does not leak all. The mixed distribution is difficult to leak and is distributed so that the leak is easy to detect.

  The material of the diaphragms 80a and 80b is a precipitation hardening stainless steel material that is excellent in corrosion resistance in fuel and excellent in strength. As a mechanism for reducing fuel pressure pulsation, this two-metal diaphragm damper 80 is provided between the fuel passage 10 and the low pressure chamber 10a.

  The double metal diaphragm damper 80 has an outer periphery sandwiched by a wave washer 101 and a washer guide 102 as wave plate springs. A washer (annular ring) 103 as a pressing member is provided with the same notch on the outer peripheral side of the front and back surfaces. The outer periphery of the washer 103 is machined to the same dimensions as the outer periphery of the two-metal diaphragm damper 80. The washer guide 102 is provided with a groove 102 a on the outer periphery of a portion that sandwiches the two-metal diaphragm damper 80.

  As a result, the double metal diaphragm damper and the washer 103 are guided by the same wall surface of the washer guide 102, and the outer peripheral welded portion 80d is not sandwiched. Therefore, the double metal diaphragm damper due to stress concentration is used. Can prevent damage.

  Further, since the washer 102 has no distinction between the front and the back, errors during assembly can be reduced, and assemblability is improved.

  The clamping force is given by the damper cover 91 via the spring washer 101. The damper cover 91 is fixed to the pump body 1 by a set screw 92.

  Thereby, by selecting the spring constant of the spring washer 101, the outer periphery of the double metal diaphragm damper can be uniformly clamped over the entire periphery with an appropriate force.

  Further, the fuel chambers 10b and 10c serving as storage containers for storing the metal diaphragm assembly (damper) 80 communicate with the fuel chamber 10a reaching the inlet of the pressurizing chamber. The fuel is sealed from the outside by an O-ring 93.

  As a result, the fuel can freely reciprocate to the fuel chamber 10c through the gap of the spring washer 101, so that the fuel can be distributed to both surfaces of the double metal diaphragm damper, and the fuel pressure pulsation is efficiently absorbed. be able to.

  A fuel pressure sensor 94 is installed on the damper cover.

  Thereby, it is possible to obtain a high-pressure fuel supply pump that can easily detect the breakage of the double metal diaphragm damper 80.

(Example 2)
Next, another embodiment in which the present invention is implemented will be described with reference to FIG.

  In this embodiment, two double metal diaphragm dampers 80 and 81 are provided between the fuel passage 10 and the low pressure chamber 10a as a mechanism for reducing fuel pressure pulsation.

  The double metal diaphragm damper 80 is sandwiched by a washer 103 and a washer guide 102 over the entire circumference. The washer 103 is provided with the same notch on the outer peripheral side of both the front and back surfaces. The outer periphery of the washer 103 is machined to the same dimensions as the outer periphery of the two-metal diaphragm damper 80. The washer guide 102 is provided with a groove 102a. Further, the fuel chambers 10b and 10c communicate with the fuel chamber 10a.

  The double metal diaphragm damper 81 has an outer periphery sandwiched between a washer 102 and a damper cover 91. The damper cover 91 is provided with a groove 91a. A groove is provided as a fuel passage in the sandwiching portion of the two-metal diaphragm damper 81 of the damper cover 91.

  A spring washer 101 is provided between the two washers 102, and a force for sandwiching the two double metal diaphragm dampers 80 and 81 by the damper cover 91 is generated via the spring washer 102. The fuel is sealed from the outside by an O-ring 93.

  Accordingly, the two double metal diaphragm dampers 80 and 81 are guided by the same wall surface as the washer 103, and the outer peripheral welds 80d and 81d are not sandwiched. Damage to the metal diaphragm dampers 80 and 81 can be prevented.

  In addition, the fuel can enter the fuel chamber 10c through the gap of the spring washer 101, and the fuel can enter the fuel chamber 110d through the groove provided in the damper cover 91. The fuel can be spread over both surfaces of the metal diaphragm dampers 80 and 81, and the fuel pressure pulsation can be absorbed efficiently.

  Since the washer 103 has no distinction between the front and back sides, errors during assembly can be reduced, and assemblability is improved.

  Further, since the two double metal diaphragm dampers are provided, it is possible to obtain a high-pressure fuel supply pump that can sufficiently absorb fuel pressure pulsation while being lightweight and compact.

(Example 3)
Next, still another embodiment in which the present invention is implemented will be described with reference to FIG.

  Two double metal diaphragm dampers 80 and 81 are provided between the fuel passage 10 and the low pressure chamber 10a as a mechanism for reducing fuel pressure pulsation. The metal diaphragm dampers 80 and 81 have different cross-sectional shapes.

The two double metal diaphragm dampers 80 and 81 are sandwiched between the washer 103 and the washer guide 102 over the entire circumference. The washer 103 is provided with the same notch on the outer peripheral side of both the front and back surfaces. The outer periphery of the washer 103 is machined to the same dimensions as the outer periphery of the two-metal diaphragm damper 80. The washer guide 102 is provided with a groove 102a. Further, the fuel chambers 10b, 10c, 10d communicate with the fuel chamber 10a.

  A spring 104 is provided between the two washers 102, and a force for sandwiching the two double metal diaphragm dampers 80 and 81 by the damper cover 91 is generated via the spring 104. The fuel is sealed from the outside by an O-ring 93.

  Accordingly, the two double metal diaphragm dampers 80 and 81 are guided by the same wall surface as the washer 103, and the outer peripheral welds 80d and 81d are not sandwiched. Damage to the metal diaphragm dampers 80 and 81 can be prevented.

  Further, the fuel can enter the fuel chambers 10c and 10d, can spread the fuel on both surfaces of the two double metal diaphragm dampers 80 and 81, and can efficiently absorb the fuel pressure pulsation. it can.

  In the double metal diaphragm damper, the absorption capability and frequency characteristics of fuel pressure pulsation change depending on the cross-sectional shape. Since the two double metal diaphragm dampers 80 and 81 have different cross-sectional shapes, it is possible to obtain a high-pressure fuel supply pump having an optimal ability to absorb fuel pressure pulsation by selecting a cross-sectional shape. The two double metal diaphragm dampers may have the same cross-sectional shape.

(Example 4)
Next, another embodiment will be described with reference to FIG. In the embodiment shown in FIG. 6, the pulsation damping mechanism using the above-described two-metal diaphragm 80 is separated from the pump and configured as an independent pulsation damping mechanism.

  In particular, a description will be given of a type in which a two-metal diaphragm is sandwiched and caulked by a casing made of rolled steel that is easy to manufacture.

  By making the pulsation damping mechanism separate, it can be installed at any location in the fuel system, so it has the advantage of excellent layout. For example, it can be installed in any part of the pump body or any part of the fuel pipe.

  That is, since the pulsation attenuation characteristic varies greatly depending on the installation position of the pulsation attenuation mechanism, setting the installation position arbitrarily is a great advantage in terms of obtaining a desired pulsation attenuation characteristic.

  In addition, there are cases where there are fuel supply systems having different pulsation damping characteristics even if the same pump is used. However, if several pulsation damping mechanisms are prepared, a desired pulsation can be achieved for a plurality of fuel supply systems. Attenuation performance is obtained.

  Furthermore, as a separate pulsation damping mechanism, it is possible to withstand poor fuel by using a metallic diaphragm, and the fuel pressure fluctuation is larger than that using a conventional rubber diaphragm. Can also withstand.

  The embodiment of FIG. 6 will be specifically described below.

  The pulsation damping mechanism of the present invention includes a two-metal diaphragm damper 80 that changes its volume in response to a change in pressure from the outside, a casing 300 that supports the two-metal diaphragm damper and configures its appearance, and a casing 300 A cover 310 for sandwiching the two-metal diaphragm damper 80, a fastening flange 320 for fastening a component in which a fluid to be pulsated is present, and a fluid for guiding the fluid to be damped to the pulsation damping mechanism The connecting pipe 330 has a passage and has a function of sealing the pulsation damping mechanism and a component in which a fluid for damping the pulsation is present.

  The casing will be described with reference to FIGS.

  The casing 300 includes a fastening flange 320 for supporting the double metal diaphragm damper 80 and fastening with a component 340 in which the fluid 360 to be damped is present, and the pulsation damping mechanism is provided with the fluid 360 to be damped. And a first space 351 for allowing the fluid 360 to act on the double metal diaphragm damper 80.

As a part for supporting the double metal diaphragm damper 80, an annular protrusion 302 is provided and supported on the support base surface 301 of the casing 300 on the same pitch circle. The outer diameter φD ₃₀₂ of the contact portion of the annular projection 302 disposed on the same pitch circle with the double metal diaphragm damper 80 does not contact the weld bead portion 80c on the outermost periphery of the double metal diaphragm damper 80. Thus, the inner diameter of the weld bead is smaller than φd _80c . That is, φD ₃₀₂ <φd _80c .

  In the support base surface 301, a portion where the annular protrusion 302 is not provided, in other words, a portion where the annular protrusion 302 is cut out is a fluid passage for communicating the fluid in the first space 351 and the fluid in the second space 352. 303 (FIG. 7).

  The casing 300 has a cover inner cylinder 304 coaxially with the annular protrusion 302, and the cover 310 is installed coaxially with the inner diameter side of the cover inner cylinder 304 using the inner diameter side surface of the cover inner cylinder 304 as a guide.

  As a material of the casing 300, in consideration of ease of forming, strength, and corrosion resistance, a material obtained by subjecting a rolled steel plate to alloy plating is used, but not limited thereto.

  The cover as the lid will be described in detail with reference to FIGS.

  The cover 310 forms an appearance together with the casing 300. The cover 310 sandwiches the two-metal diaphragm damper 80 disposed in coaxial contact with the annular projection portion 302 of the casing 300 from the direction facing the first space 350, and uses the two-metal diaphragm damper 80 as a reference. The second space 352 is formed on the side facing the first space 351.

Similar to the casing 300, the cover 310 is provided with an annular protrusion 312 for supporting the two-metal diaphragm 80, that is, for sandwiching with the casing. As in the case of the casing 300, the outer diameter φD ₃₁₂ of the contact portion of the annular protrusion 312 with the double metal diaphragm damper 80 is welded so as not to contact the weld bead portion 80c on the outermost periphery of the double metal diaphragm damper 80. It is smaller than the bead inner diameter φd _80c . That is, φD ₃₁₂ <
φd _80c .

  Similar to the casing, the annular protrusion 312 is not provided, that is, a portion where the annular protrusion is notched serves as a fluid passage 313 (FIG. 8) for communicating the fluid in the first space 351 and the fluid in the second space 352. .

A guide 314 is provided on the outer peripheral side of the annular protrusion 312 supporting the two-metal diaphragm 80 in contact with the cover. This guide 314 regulates the radial position of the two-piece metal diaphragm 80. Due to the relationship between the position of the double metal diaphragm 80 and the aforementioned relationship of φD ₃₀₂ <φd _80c , φD ₃₁₂ <φd _80c , the weld bead portion 80 d of the double metal diaphragm 80 is completely supported by It has a structure that escapes from.

  In order to allow the first space 351 and the second space 352 to communicate with each other, a guide 314 is also cut out as the passage 313. That is, the portion that is not a guide by the notch communicates the fluid in the first space 351 and the fluid in the second space 352 together with the portion where the annular protrusion 312 is not provided (the portion where the annular protrusion 312 is notched). The fluid passage 313 is used.

  An O-ring 370 is disposed on the outer peripheral side of the cover 310 in order to prevent fuel leakage to the outside. O-ring sealing is performed by a groove 315 formed in the cover 310 and a cover-containing cylindrical portion 314 of the casing. The cover is crimped by plastically deforming and bending the casing front end 305, and is fixed together with the two-piece metal diaphragm 80.

  Stainless steel is used as the material of the cover 310 in consideration of strength and corrosion resistance, but is not limited thereto.

  The connecting pipe 330 and the fastening flange 320 will be described with reference to FIG.

  The connection pipe 330 is a pipe for guiding the fluid from a part 340 (for example, a pump and a pipe) in which the fluid to be pulsated is damped to the first space 351 of the pulsation damping mechanism, and should dampen the pulsation. It enters and joins the counterpart 340 where the fluid exists. An O-ring 371 is installed on the outer periphery of the connecting pipe to seal the fluid with the counterpart component 340.

  As the material of the connecting pipe 330, a steel material plated with steel is used, but this is not restrictive. Further, as the material of the O-rings 370 and 371, fuel-resistant fluororubber, in particular, ternary or other fluorinated rubber that is not a one-component or two-component system is used.

  The fastening flange 320 is disposed so as to be sandwiched between the casing 300 and the connecting pipe 330. It has a plate-like shape for fastening with the flat portion of the part 340 where the fluid to be pulsated is present, and has one or two holes 321 for screwing.

  As a material for the fastening flange 330, a rolled steel plate that has been plated is used, but this is not a limitation.

  In this pulsation damping mechanism, a hole 341 into which the connecting pipe 330 can be inserted and a screw hole 321 for fastening are provided in the part 340 where the fluid to be damped is present, and the hole 340 into which the fastening pipe 330 can be inserted is O. A fastening tube 330 with a ring seal mechanism is inserted and attached by a fastening flange 320 with a screw 380.

  Hereinafter, the operation of the present pulsation damping mechanism will be described with reference to FIG.

The fluid in the part 340 where the fluid for damping the pulsation is present is guided to the first space 351 of the pulsation damping mechanism through the connecting pipe 330. The first space 351 is formed by notching the passage 303 formed by the cutout portion of the annular protrusion 302 of the casing, the gap between the outer peripheral side of the two-metal diaphragm damper and the casing, and the annular protrusion of the cover. The passage 313 communicates with the second space (FIG. 9). That is, when the pressure of the fluid to attenuate the pulsation increases, the pressure propagates to the first space 351 and the second space 352, and the volume of the double metal diaphragm damper 80 is deformed to be reduced. This acts to reduce the pressure. On the other hand, when the pressure of the fluid that should attenuate the pulsation decreases, the volume of the double metal diaphragm damper 80 is deformed to increase, thereby suppressing the decrease in the pressure.

  The first space 351 and the second space 352 themselves have a volume in the fluid, and the space itself has a pulsation damping function. Further, the pulsation can be attenuated by elastic deformation of the casing.

  FIG. 10 is an example in which the axial direction of the connecting pipe 330 and the axial direction of the diaphragm 80 are configured in parallel (coaxial).

  FIG. 11 shows a screw structure 332 on the outer peripheral side of the connecting pipe instead of the fastening flange and the connecting pipe. Not only this screw structure but also a method of coupling with a component in which a fluid that attenuates pulsation is present can be a sealing method that is generally used for pipe connection.

  FIG. 12 shows an example in which two metal diaphragms 80 and 81 are used. On the basis of the embodiment of FIG. 6, the two member metal diaphragms 80 can be installed by sandwiching the annular member 390 between the two member metal diaphragms, and the third space 353 is formed.

  Similar to the cover 310 in the embodiment of FIG. 6, the annular member 390 is installed on the inner diameter side of the case 300 coaxially with the cover inner cylinder 304 using the inner diameter side surface of the cover inner cylinder 304 as a guide.

The annular member 390 has annular protrusions 392 that contact and support the two-piece metal diaphragm 80 on both sides of the member. The annular protrusion 392 has a dimension for escaping the weld bead portions 80d and 81d of the double metal diaphragms 80 and 81, similarly to the annular protrusion 312 of the cover 310 in the embodiment of FIG.

  The annular member 390 is provided with guides 394 and 395 for restricting the radial position of the two-piece metal diaphragms 80 and 81, similarly to the guide 314 of the cover 310 in the embodiment of FIG. In the case where no guide is provided on the cover 310, the guide 395 can be provided on the annular member 390.

  Similar to the fluid passage portion 313 (FIG. 8) of the cover 310 in the embodiment of FIG. 6, the annular member 390 has a fluid passage 393, and has a first space and a third space, and a third space and a second space. A passage to be communicated is formed.

  By using two double metal diaphragms with the above-described structure, the total volume change amount of the double metal diaphragm with respect to the pressure change is simply doubled, and a larger pulsation damping function can be exhibited.

  If necessary, by using the annular member 390, three or more double metal diaphragms 80 can be installed, and an even greater pulsation damping function can be obtained.

  FIG. 13 shows an example in which three pieces of two-plate metal diaphragms 80, 81 and 82 are used.

  If the three double metal diaphragm dampers 80, 81 and 82 are provided between the fuel passage 10 and the low pressure chamber 10a, the fuel pressure pulsation can be further reduced.

  The double metal diaphragm damper 80 is sandwiched by a washer 103 and a washer guide 102 over the entire circumference. The washer 103 is provided with the same notch on the outer peripheral side of both the front and back surfaces. The outer periphery of the washer 103 is machined to the same dimensions as the outer periphery of the two-metal diaphragm damper 80. The washer guide 102 is provided with a groove 102a. Further, the fuel chambers 10b and 10c communicate with the fuel chamber 10a.

  The double metal diaphragm damper 81 is sandwiched by two washers 103 over the entire circumference.

  The double metal diaphragm damper 82 has an outer periphery sandwiched between a washer 103 and a damper cover 91. The damper cover 91 is provided with a groove 91a. A groove is provided as a fuel passage in the sandwiching portion of the two-metal diaphragm damper 81 of the damper cover 91.

  Two spring washers 101 are provided between the three double metal diaphragm dampers 80, 81 and 82, and the three double metal diaphragm dampers 80, 80 are provided by the damper cover 91 via the spring washers 101. The force which pinches 81 and 82 is generated. The fuel is sealed from the outside by an O-ring 93.

  As a result, the three double metal diaphragm dampers 80 and 81 are guided by the same wall surface as the washer 103, and the outer peripheral welds 80d and 81d are not sandwiched. Damage to the metal diaphragm dampers 80 and 81 can be prevented.

  Further, the fuel can enter the fuel chamber 10c through the gap of the spring washer 101, and the fuel can enter the fuel chambers 110d and 10e through the groove provided in the damper cover 91. Fuel can be spread over both surfaces of the sheet metal diaphragm dampers 80, 81 and 82, and fuel pressure pulsation can be absorbed efficiently.

  Since the washer 103 has no distinction between the front and back sides, errors during assembly can be reduced, and assemblability is improved.

  Further, since the three double metal diaphragm dampers are provided, it is possible to obtain a high-pressure fuel supply pump that can sufficiently absorb fuel pressure pulsation while being lightweight and compact.

  According to the embodiment described above, the fuel pressure pulsation can be efficiently performed by fixing the two-metal diaphragm damper in which the gas is sealed inside by welding the outer peripheral portions of the two metal diaphragms by an appropriate method. It is possible to provide a high-pressure fuel supply pump that can absorb fuel and supply fuel to the fuel injection valve with a stable fuel pressure.

  Furthermore, it is possible to more efficiently absorb the fuel pressure pulsation by fixing a plurality of two-metal diaphragm dampers by an appropriate method, and to supply the fuel to the fuel injection valve with a stable fuel pressure.

  Specifically, when a two-metal diaphragm damper is used as a mechanism for reducing fuel pressure pulsation, there is a problem in that when the weld is sandwiched and fixed, stress concentration occurs in the weld and the weld is peeled off. . In this embodiment, the entire inner circumference or part of the welded portion is sandwiched between the annular ring and the corrugated spring so as to receive the fixing force, so that the welded portion is not peeled off. In addition, fuel can be spread across both sides of the double metal diaphragm damper.

  Furthermore, when a plurality of metal diaphragm assemblies (two-plate metal diaphragm dampers) are used, the annular ring or corrugated spring of the pressing member is shared by two adjacent metal diaphragm assemblies. I was able to reduce the score.

1 is an overall longitudinal sectional view of a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. 1 is a system configuration diagram showing an example of a fuel supply system using a high-pressure fuel supply pump in which the present invention is implemented. 1 is a partial longitudinal sectional view of a high-pressure fuel supply pump according to a first embodiment in which the present invention is implemented. It is a partial longitudinal cross-sectional view of the high pressure fuel supply pump which becomes 3rd Example by which this invention was implemented. It is a fragmentary longitudinal cross-sectional view of the high pressure fuel supply pump which becomes 4th Example with which this invention was implemented. It is a whole longitudinal section used as the 1st example of the damper mechanism in which the present invention was carried out. It is the expanded sectional view which expanded the portion of the housing. It is the expanded sectional view which expanded the portion of the housing. It is the elements on larger scale which show the flow of fuel. It is a whole longitudinal cross-sectional view which becomes 2nd Example of the damper mechanism with which this invention was implemented. It is a whole longitudinal cross-sectional view which becomes 3rd Example of the damper mechanism with which this invention was implemented. It is a whole longitudinal cross-sectional view which becomes 4th Example of the damper mechanism with which this invention was implemented. It is a whole longitudinal cross-sectional view of the high pressure fuel supply pump which becomes 5th Example by which this invention was implemented.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pump body, 2 ... Plunger, 3 ... Lifter, 4 ... Spring, 5 ... Intake valve, 6 ... Discharge valve, 7 ... Cam, 12 ... Pressurization chamber, 10b, 10c ... Fuel chamber (storage container part), 80 ... Metal diaphragm damper (assembly), 80d ... outer peripheral weld, 91 ... damper cover, 93 ... O-ring,
101 ... wave washer, 103 ... washer.

Claims (13)

In the damper mechanism that is installed in the low-pressure side passage leading to the pressurizing chamber of the pump that pressurizes the fuel and reduces fuel pulsation,
The damper mechanism includes at least two metal diaphragm assemblies (80, 81, 82) each having a set of two plates whose entire circumference is welded (80d, 81d, 82d) , and gas is sealed inside.
The metal diaphragm assembly (80, 81, 82) is stored in storage containers (10b, 10c) communicating with the low pressure passage,
The storage container (10b, 10c) is sealed from the outside air by the lid (91, 310) ,
The damper mechanism further the welded portion of the metal diaphragm Kumitai (80, 81, 82) (80d, 81d, 82d) at the inner portion of pinching the metal diaphragm assemblies (the 80, 81, 82) from the top and bottom A pair of pressing members (102, 103, 302, 312, 390, 392) ;
Furthermore, the said weld metal diaphragms Kumitai (80, 81, 82) between the two sets of metal diaphragm assemblies (80, 81, 82) (80d, 81d, 82d) in the inner part of the two sets A damper mechanism provided with members (101, 103, 104, 390) for maintaining the distance between the metal diaphragm assemblies (80, 81 or 81, 82) . In claim 1,
A damper mechanism in which the storage container (10b, 10c) is integrally formed or attached to a low-pressure fuel passage member that reaches the pump. In claim 1,
Member (101,103,104,390) to maintain the spacing is composed of at least one of the metal diaphragm assembly body between an annular ring provided on the (103,390) or an annular elastic member (101, 104) Damper mechanism. A high-pressure fuel supply pump that pressurizes fuel and supplies the internal combustion engine with a low-pressure passage formed integrally with a body of the pump, and a high-pressure fuel tank provided with a damper mechanism installed in the low-pressure passage to reduce fuel pulsation In the fuel supply pump,
The damper mechanism includes at least two metal diaphragm assemblies (80, 81, 82) each having a set of two plates whose entire circumference is welded (80d, 81d, 82d) , and gas is sealed inside.
The metal diaphragm assembly (80, 81, 82) is stored in storage containers (10b, 10c) communicating with the low pressure passage,
The storage container (10b, 10c) is sealed from the outside air by the lid (91, 310) ,
The damper mechanism further the welded portion of the metal diaphragm Kumitai (80, 81, 82) (80d, 81d, 82d) at the inner portion of pinching the metal diaphragm assemblies (the 80, 81, 82) from the top and bottom A pair of pressing members (102, 103, 302, 312, 390, 392) ;
Furthermore, the said weld metal diaphragms Kumitai (80, 81, 82) between the two sets of metal diaphragm assemblies (80, 81, 82) (80d, 81d, 82d) in the inner part of the two sets A high-pressure fuel supply pump provided with members (101, 103, 104, 390) for maintaining the distance between the metal diaphragm assemblies (80, 81, 82) . 5. The pump body according to claim 4, wherein a joint for connecting a low-pressure side pipe is provided in the body of the pump, and fuel is led from the joint to the storage container part (10b, 10c) , and the storage container part ( 10b, 10c) a high pressure fuel supply pump in which fuel is guided to the pressurizing chamber (12) of the pump via a low pressure passage and a suction valve (5) . 5. The high-pressure fuel supply pump according to claim 4, wherein the storage container portion (10b, 10c) is adjacent to a pressurizing chamber (12) formed in the body (1) of the pump with a wall therebetween. 5. The lid (91, 310) and the one metal diaphragm assembly so that a common fuel pressure acts on each damper surface of the metal diaphragm assembly (80, 81, 82). (80, 81, 82) , between the two metal diaphragm assemblies (80, 81, 82) and between the storage container and the other metal diaphragm assembly (80, 81, 82) . A high-pressure fuel supply pump with a communication passage that communicates. The low-pressure fuel passage that connects the storage container portion (10b, 10c) and a low-pressure passage portion that guides fuel to a pressurization chamber (12) provided in the pump is described in claim 4. A high-pressure fuel supply pump that is drilled in the body of the pump from the container (10b, 10c) to the low-pressure passage. In those described in claim 4, wherein the lid (91,310) is attached a pressure sensor (94), the said pressure sensor in said container in the pressure detecting portion of (94) (10b, 10c) High pressure fuel supply pump, where the pressure of is guided. What is described in claim 4,
The spacing member (101, 103, 104, 390) is at least one of an annular ring ( 103) or an annular elastic member (101) provided between the metal diaphragm assemblies (80, 81, 82) . A high-pressure fuel supply pump consisting of In any one of claims 4 or 10,
The annular elastic member (101) is a high-pressure fuel supply pump constituted by an annular corrugated spring (101) . In the thing in any one of Claim 4 or 10,
A high-pressure fuel supply pump, wherein the outer periphery of the two sets of metal diaphragm dampers is guided. What is described in claim 12,
The two sets of metal diaphragm Kumitai elastic member (101) disposed between the (80, 81, 82) or annular ring (103) of at least one of the outer periphery of the metal diaphragm Kumitai (80, 81, 82 The high-pressure fuel supply pump is guided by the same wall surface as the outer periphery of ) .

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