Pulsation damper for a fuel pump

Abstract

Pulsation dampener (100), comprising: an upper membrane (10A); a lower membrane (10B, 20A) designed to form a sealed space with the upper membrane (10A) at a predetermined pressure, into which an inert gas is filled; and a deformation suppression part (40, 50, 60, 70) formed from an elastic material and comprising an inner cylindrical region (41), and an extension region (42, 62) extending from a central region on an outer circumferential surface of the inner cylindrical region (41), such that the extension region (42, 62) extends outwards from a central axis of the inner cylindrical region (41), wherein the deformation suppression part (40, 50, 60, 70) is arranged within the sealed space such that an outer circumference of the expansion area (42, 62) abuts inner walls of the upper membrane (10A) and the lower membrane (10B, 20A), and wherein a first channel (431, 531) is formed on an outer circumferential region of the extension region (42, 62), which connects a first space, surrounded by an outer circumferential surface of the extension region (42, 62), the upper membrane (10A) and the lower membrane (10B, 20A), with a second space on the side of the extension region (42, 62) which is the side of the extension region (42, 62) to the upper membrane (10A), and a third space on the side of the extension region (42, 62) which is the side of the extension region (42, 62) to the lower membrane (10B, 20A).

Description

Technical field

[0001] The present invention relates to a pulsation damper, in particular a pulsation damper capable of effectively reducing the pulsation that occurs in a fuel pump and the like. State of the art

[0002] A pulsation damper, which is installed in a conventional high-pressure fuel pump or the like, is known (see, for example, patent literature 1), wherein a diaphragm in a pressure chamber of a housing body absorbs and reduces the pulsation of a fluid which is introduced into the pressure chamber through an inlet channel.

[0003] In this type of conventional pulsation damper, the diaphragm is formed by pressing a metal plate, for example made of stainless steel, such that it has a protruding area in one direction, and a ceiling area (middle area) of the protruding area forms a flat surface parallel to a flange on the outer circumference of the diaphragm.

[0004] The pulsation dampener is formed by carrying out a full circumferential welding of the diaphragm to a predetermined flat plate (metal plate), or by inserting a flat plate between the two diaphragms and carrying out a full circumferential welding of the metal plate and the diaphragms, or by arranging the two diaphragms so that they face each other directly, without inserting a metal plate, and carrying out a full circumferential welding to form the pulsation dampener.

[0005] In this process, an inert gas such as helium and nitrogen is sealed as an inner gas at a predetermined pressure in a space bounded by the membrane and the metal plate, or in the space bounded by two membranes.

[0006] Patent reference 2 discloses a prior art relating to a pulsation damper with two membranes arranged on both sides of a plate-shaped element, wherein an elastic element is arranged in the plate-shaped element to prevent inner sides of a central region of the membranes from coming into contact with the plate-shaped element in the event of excessive pressure fluctuation (pulsation) and deflection of the membranes in a direction in which they approach each other. With this technique, even in the event of excessive pressure fluctuation, the membranes are prevented from being damaged or deformed, the reduction of the intrinsic pulsation absorption effect can be prevented, and a reduction in the service life of the membranes, which occurs due to accelerated fatigue in stress-prone areas of the membrane, can be avoided.

[0007] US 2015 0 260 133 A1 describes a diaphragm damper in which a high-pressure gas is enclosed in a high-pressure chamber formed by two disc-shaped metal diaphragms whose outer circumferential sections are connected to each other, with elastic elements arranged inside the high-pressure chamber. List of citations from patent literature [PTL 1] Unexamined Japanese patent application publication JP 2007-309118 A [PTL 2] Unexamined Japanese patent application publication JP 2012-197732 A Summary of the invention: Technical problem

[0008] According to the prior art as defined in JP 2012-197732 A, excessive deformation or damage to the diaphragms is prevented even when excessive pressure fluctuation occurs. However, there is a need to provide an element to suppress excessive deformation in a manner that places it between flange areas on a circumference of the pair of diaphragms, with the element being located in an interior space between the diaphragms, so there was concern that this would complicate the design of the pulsation damper.

[0009] Therefore, the objective of the present invention is to create a pulsation damper that can prevent excessive deformation of the membranes even when significant pressure fluctuations occur, wherein an element for suppressing the deformation can be arranged inside the membranes in a very simple and reliable manner. Solution to the problem

[0010] To achieve the aforementioned objectives, a pulsation dampener according to the present invention comprises an upper diaphragm, a lower diaphragm for forming a sealed space at a predetermined pressure with the upper diaphragm, in which an inert gas is filled, and a deformation suppression element formed from an elastic material, having an inner cylindrical region and an extension region extending from a central part of an outer circumferential surface of the inner cylindrical region such that it extends outwards from a central axis of the inner cylindrical region, wherein the deformation suppression element is arranged in the sealed space such that an outer circumference of the extension region abuts against inner walls of the upper diaphragm and the lower diaphragm.

[0011] Furthermore, in the pulsation damper according to the present invention, the outer circumference of the expansion area of ​​the deformation suppression part comprises an outer cylindrical area that projects in a direction of the central axis of the pulsation damper, and a top and a bottom of the outer cylindrical area abut against the inner walls of the upper diaphragm and the lower diaphragm.

[0012] Furthermore, a first channel is formed on an outer circumferential area of ​​the extension area, which connects a first space, surrounded by an outer circumferential surface of the extension area, the upper membrane and the lower membrane, with a second space on one side of the extension area of ​​the upper membrane and a third space on one side of the extension area of ​​the lower membrane.

[0013] In an unloaded state, the inner cylindrical region can form a predetermined space between at least either the upper or the lower membrane. A second channel, connecting one side of the inner cylindrical region (serving as a fourth space) to an outer side of the inner cylindrical region (serving as a second and / or third space), may be formed on at least either the side of the upper membrane or the side of the lower membrane of the inner cylindrical region.

[0014] Furthermore, the extension area may include a hole or notch that connects the side of the upper membrane and the side of the lower membrane.

[0015] In the pulsation damper of the present invention, at least either a contact area on the outer circumferential area of ​​the expansion area with the upper membrane or a contact area of ​​the outer circumferential area of ​​the expansion area with the lower membrane can be formed from a curved surface.

[0016] In this case, the radius of curvature of the curved surface can be either equal to the radius of curvature of an inner wall of the upper membrane in contact with the curved surface or equal to the radius of curvature of an inner wall of the lower membrane in contact with the curved surface.

[0017] Furthermore, in a pulsation damper according to the present invention, when a pressure on an outer surface and a pressure on an inner surface are equal, a central region of at least either the upper diaphragm or the lower diaphragm can be shaped to protrude outwards.

[0018] The pulsation dampener may further comprise an upper cover and a lower cover arranged to enclose the upper diaphragm and the lower diaphragm.

[0019] The pulsation dampener according to the present invention comprises a diaphragm, a plate-like element configured to form a sealed space with a predetermined pressure with the diaphragm, in which an inert gas is filled, and a deformation suppression element formed from an elastic material, and having an inner cylindrical region and an extension region extending from a central region on an outer circumferential surface of the inner cylindrical region, such that it extends outwards from a central axis of the inner cylindrical region, wherein the deformation suppression element is arranged within the sealed space such that an outer circumference of the extension region abuts against inner walls of the diaphragm and the plate-like element. Advantageous effect of the invention

[0020] In the pulsation damper according to the present invention, the deformation suppression part is arranged in the interior space surrounded by the membranes, so that excessive deformation of the membranes can be suppressed even when strong pulsation occurs.

[0021] Furthermore, since the deformation suppression part has an inner cylindrical area and an extension area extends from the inner cylindrical area to an outer side of the central area of ​​the outer circumferential surface of the inner cylindrical area, and the outer circumference of the extension area is arranged such that it abuts an inner wall of the membranes, the deformation suppression part can be fixed without instability by simply arranging the deformation suppression part in the interior of the membranes, without the need for special means (such as means for inserting the part between flanges on an outer circumference of the two membranes) for arranging the deformation suppression part in the interior of the membranes.

[0022] Furthermore, if the inner walls of the upper and lower membranes abut against the upper and lower sides of the first cylindrical section, and the inner surface is further compressed on the inside of the abutment areas, the entire area of ​​the first to fourth chambers can be used as a damping volume, and the pulsation reduction effect is not impaired. In this case, the first to fourth chambers are connected to each other by adding a connecting hole to the deformation suppression component, and the entire deformation suppression component can be lighter.

[0023] Furthermore, a space exists between the membranes and the deformation suppression element in a state in which the pulsation damper of the present invention is in an unloaded state, the deformation process of the membranes is not hindered unless excessive pressure is exerted on them, and an advantageous pulsation prevention function can be exercised.

[0024] In the pulsation damper according to the present invention, the contact areas between the deformation suppression element and the diaphragms are formed from curved surfaces, so that a tight surface contact between the deformation suppression element and the diaphragms is achieved, and the position of the deformation suppression element can be stabilized. The radius of curvature of the curved surfaces should preferably be equal to the radius of curvature of the inner walls of the diaphragm.

[0025] The pulsation damper according to the invention can further comprise a central cylindrical region that projects from the expansion region in one direction along a central axis of the deformation suppression part. In this case, a plurality of central cylindrical regions can be present at predetermined intervals around the expansion region.

[0026] If the pulsation damper further comprises an upper and a lower cover with the upper and lower diaphragms sandwiched between them, deformation is suppressed both when the upper and lower diaphragms are excessively contracted and when they are excessively stretched, thus further reducing diaphragm fatigue. Since the diaphragms do not undergo plastic deformation, their pulsation damping effect is not impaired. Brief description of the drawings Fig. Figure 1 is a cross-section in which a pulsation damper according to a first embodiment of the invention is cut along an imaginary plane which includes a center line of the pulsation damper. Fig. Figure 2 is a top view of the pulsation damper according to the first embodiment of the invention. Fig. Figure 3 is a perspective view of the external appearance of a deformation suppression part, which is in Fig. 1 is shown. Fig. Figure 4 is an enlarged view of area A in Fig. 1. Fig. Figure 5 is a cross-section showing a state in which a membrane of the pulsation damper according to the first embodiment of the invention is deformed inwards by an external pressure. Fig. Figure 6 is a cross-section in which a pulsation damper according to a second embodiment of the invention is cut along an imaginary plane which encloses the center line of the pulsation damper. Fig. Figure 7 is a perspective view showing the external appearance of a deformation suppression part that is in Fig. 6 is shown. Fig. Figure 8 is a cross-section showing a state in which a membrane of the pulsation damper according to the second embodiment of the invention is deformed inwards by external pressure. Fig. Figure 9 is a perspective view showing the external appearance of a deformation suppression part used in a pulsation damper according to a third embodiment of the present invention. Fig. Figure 10 is a cross-section in which a pulsation damper according to a fourth embodiment of the invention is cut along an imaginary plane which includes a center line of the pulsation damper. Fig. Figure 11 is a cross-section in which a membrane of the pulsation damper according to a fifth embodiment of the invention is cut open along an imaginary line that includes the center line of the pulsation damper. Fig. Figure 12 is a cross-section in which a pulsation damper according to a sixth embodiment of the invention is cut along an imaginary plane which includes the center line of the pulsation damper. Fig. Figure 13 is a perspective view showing the external appearance of a deformation suppression part that is in Fig. 12 is shown. Fig. Figure 14 is a cross-section showing a state in which a membrane of the pulsation damper according to the sixth embodiment of the invention is deformed inwards by external pressure. Fig. Figure 15 is a cross-section in which a pulsation damper according to a seventh embodiment of the invention is cut along an imaginary plane which includes the center line of the pulsation damper. Description of embodiments: First embodiment

[0027] Fig. Figure 1 is a cross-section in which a pulsation dampener according to a first embodiment of the present invention is cut along an imaginary plane that runs through a center line of the pulsation dampener (hereinafter referred to as the "central cross-section"), and Fig. 2 is a top view of the pulsation dampener according to Fig. 1.

[0028] As in the Fig. 1 and Fig. As shown in Figure 2, a pulsation damper 100 according to a first embodiment is formed from two diaphragms 10 (an upper diaphragm 10A and a lower diaphragm 10B) with identical shapes and teeth facing and resting against each other. These diaphragms contain an internal space containing a deformation suppression element 40, which is designed to suppress deformation of both diaphragms 10A and 10B. The annular flange regions 11 on the outer circumference of both diaphragms 10A and 10B have been subjected to full-ring welding by laser welding or the like, in a state where an inert gas such as helium and nitrogen is sealed inside at a predetermined pressure. The deformation suppression element 40 is arranged in an internal space of the upper and lower diaphragms 10A and 10B such that a central axis O2 (see Figure 2) is defined. Fig. 3) the deformation suppression part 40 coincides with a central axis O1 of the pulsation damper 100.

[0029] Fig. Figure 1 shows a state in which the internal pressure (charge pressure of the inert gas) and the external pressure of the pulsation damper 100 are equal. In a state in which this pulsation damper 100 is located in the atmosphere (in other words, in a state in which the external pressure is lower than the internal pressure of the pulsation damper 100), the pulsation damper 100 is shaped such that a central region is further extended, as shown by the dashed line, which is labelled with reference numeral 10P, compared to a state in which the internal and external pressures of the pulsation damper 100 are equal (reference numeral 10).

[0030] In other words, in a state prior to welding the flange area 11, each membrane 10 used as a component is preformed, as shown in Fig. 1 shown.

[0031] Each membrane 10 is shaped such that horizontal cross-sectional areas of the respective regions have a round shape, by carrying out a plastic deformation such as pressing a sheet of metal, such as a plate of stainless steel.

[0032] Each membrane 10 has a central curved region 13 at the center of the central cross-section, which has a center of curvature designated by reference numeral R13C and a radius of curvature R13, and an annular curved region 14, which is arranged on a circumference of the central curved region 13 and has a center of curvature designated by reference numeral R14C on the central cross-section, and a radius of curvature R14. The radius of curvature R13 is larger than the radius of curvature R14.

[0033] In its external appearance, the membrane 10 has an annular curved area 14 arranged annularly on an outer side in the radial direction of the central curved area 13. That is, each membrane 10 has an annular curved area 14 and a projecting area 12 with a domed ceiling area, the projecting area 12 projecting on one side of the annular flange area 11.

[0034] The center of curvature R13C of the central curved region 13 and the center of curvature R14C of the annular curved region 14 are each located in different positions on opposite sides (inner wall side of the projecting region 12) from the projection direction of the projecting region 12, and the center of curvature R13C of the central curved region 13 is located on the center of the axis O1 of the membrane 10.

[0035] The following section describes the deformation suppression part 40 in more detail with regard to the Fig. 3 and Fig. 4 described.

[0036] Fig. Figure 3 is a perspective view of the external appearance of the deformation suppression part 40, which is located in Fig. 1 is shown, and Fig. Figure 4 is an enlarged view of area A in Fig. 1. In the Fig. 3 and Fig. 4 denotes the same reference numbers as in the Fig. 1 and Fig. 2 identical or corresponding parts.

[0037] The deformation suppression element 40 is formed approximately ring-shaped around a central axis O2 from an elastic material with an elasticity such as rubber, and comprises a first cylindrical area (inner cylindrical area) 41 centered around the central axis O2 and having a predetermined width (height) in the direction of the central axis O2, an extension area 42 that extends ring-shaped outwards from a central area of ​​the outer circumferential surface of the first cylindrical area 41 and has a width in the direction of the central axis O2 that is smaller than that of the first cylindrical area 41, and a second cylindrical area (outer cylindrical area) 43 with a width (height) smaller than the width of the first cylindrical area 41 in the direction of the central axis O2 and with a width (height) greater than the width of the extension area 42 in the direction of the central axis O2.

[0038] A plurality of (12, in the example of Fig. 3) Groove-shaped first channels 431 are formed on the outer circumferential region of the second cylindrical region 43 in the direction of the central axis O2. Furthermore, a groove-shaped second channel 411 is formed on an upper surface (end region on the side of the upper membrane 10A) and a lower surface (end region on the side of the lower membrane 10B) of the first cylindrical region 41, connecting an inner and an outer surface of the first cylindrical region 41. The number of first channels 431 is not limited to 12, and likewise, the number of second channels 411 formed on each of the upper and lower surfaces of the first cylindrical region 41 can be two or more.

[0039] Furthermore, an outer circumferential surface 432A at the upper end and an outer circumferential surface 432B at the lower end of the second cylindrical region 43 are each designed as curved surfaces.

[0040] As previously described, the deformation suppression element 40 is arranged within a space sealed by the two membranes 10A and 10B. Due to the arrangement of the element 40, regardless of whether the external pressure of the pulsation damper 100, in which an inert gas is sealed, is equal to or lower than the internal pressure in the chamber, the deformation suppression element 40 is not affected. Fig. 4, the area designated by reference numeral B, has outer circumferential surfaces 432 at the upper / lower end (outer circumferential surface 432A at the upper end and outer circumferential surface 432B at the lower end) of the second cylindrical area 43, which are designed as curved surfaces, to abut against the inner walls near the outer circumference of the upper membrane 10A and the lower membrane 10B.

[0041] This secures the deformation suppression element 40 and positions it stably and precisely in the center of the two diaphragms 10, i.e., such that the central axes O1 and O2 coincide without the need for special fasteners. Furthermore, the position of the deformation suppression element 40 will not shift during operation of the pulsation damper.

[0042] In order for the outer circumferential surfaces 432 to contact (aft) the inner walls of the respective membranes 10 at the upper / lower end within the area marked with reference numeral B, and thus for the deformation suppression element 40 to be stably arranged in the interior space between the two membranes 10, it is, for example, preferred to design the radius of curvature of the outer circumferential surfaces 432 at the upper / lower end to correspond to the radius of curvature of the inner wall of the membrane 10 at the contact area (in the example from Fig. 4, whose radius of curvature is designated by the reference numeral R43, and the center of curvature is designated by the reference numeral R43C), or even if the radii of curvature do not correspond to each other, it becomes possible to utilize the elasticity of the deformation suppression part 40, so that the surfaces and the inner walls are in close contact due to the elastic deformation of the outer circumferential surfaces 432 at the upper / lower end.

[0043] Furthermore, in a state where the outer circumferential surfaces 432 at the upper / lower end of the second cylindrical region 43 abut against the inner walls of the respective membranes 10, the first channels 431 are configured such that the upper and lower ends 433 (upper end 433A and lower end 433B) of the first channel 431 open towards the space on the side of the upper membrane 10A and the side of the lower membrane 10B, respectively. That is, a bottom surface area 43B of the first channel 431 is located closer to the central axis O2 of the outer circumferential surface of the deformation suppression element 40 (outer circumferential surface of the second cylindrical region 43).

[0044] The outer circumferential surfaces 432 at the upper / lower end of the second cylindrical region 43 abut against the inner walls near the circumference of the respective membranes 10, so that a first space S1 is formed between the outer circumferential surface of the deformation suppression part 40 (the outer circumferential surface of the second cylindrical region 43) and both membranes.

[0045] Furthermore, since the respective upper and lower ends 433 of the first channel 431 are each open to the spaces formed on the sides of the respective membranes 10, the first space S1 communicates with a second space S2 and a third space S3 between the extension area 42 of the deformation suppression part 40 and the respective membranes 10.

[0046] Furthermore, the height of the first cylindrical section 41 is dimensioned such that a space G is provided between the respective membranes 10 and the upper and lower surfaces 413 (upper surface 413A and lower surface 413B) of the first cylindrical section 41, regardless of whether the external pressure of the pulsation damper 100 in which the inert gas is enclosed is the same as or lower than its internal pressure.

[0047] If the pulsation damper 100 is arranged in a fuel pump, and, for example, a pulsation occurs in the external pressure on the pulsation damper 100 due to pressure from fuel within a pressure chamber of a fuel pump, the upper diaphragm 10A and the lower diaphragm 10B deform by expansion or contraction in the direction of the central axis O1, thereby damping the pulsation.

[0048] A space G is present between the inner walls of the respective diaphragm 10 and (the upper surface 413A and the lower surface 413B) of the first cylinder area 41 of the deformation suppression part 40, in a state in which the pulsation damper is in the unloaded state, and a deformation effect of the diaphragm 10 is not hindered unless excessive pressure occurs, and an advantageous pulsation prevention function is ensured.

[0049] Since the first channel 431 is formed on the second cylindrical area 43, the first chamber S1, which is surrounded by the outer circumferential surface (the outer circumferential area) of the second cylindrical area 43 and the two diaphragms 10, communicates with the second chamber S2 on the side of the extension area 42 to the upper diaphragm 10A and with the third chamber S3 on its side to the lower diaphragm 10B, so that the first chamber S1 can be used as a damping volume, which contributes to the effect of reducing pulsation. That is, the volume on the inside of the diaphragm 10 can be used effectively.

[0050] In a state where both membranes are strongly contracted, as in Fig. As shown in Figure 5, the membranes 10 strike against the upper and lower surfaces 413A and 413B ( Fig. 4) of the first cylindrical section 41 of the deformation suppression part 40, thereby suppressing excessive deformation of at least the area outside the stop area of ​​the diaphragm 10. In Fig. 5 The dashed line indicates a state in which the internal pressure (charge pressure of the inert gas) and the external pressure of the pulsation damper are equal to 100.

[0051] The upper and lower membranes 10A and 10B are equipped with the central curved area 13, as shown in Fig. 1 is shown, so that in comparison to the case in which the central curved area 13 is not present (in a case in which a protruding area of ​​the membrane forms a parallel surface with a flange area), the extent of the deformation of the membrane when pulsation occurs due to external pressure is large, and the effect of reducing the pulsation is also large, but the large extent of the deformation of the membrane has the disadvantage of a reduced lifetime of the membrane.

[0052] However, if, in the first embodiment of the present invention, as in Fig. As shown in Figure 5, the extent of the contraction of the membranes 10 is large, the membranes 10 strike against the upper surface 413A and the lower surface 413B of the first cylindrical area of ​​the deformation suppression part 40, thus preventing excessive deformation of the membrane 10.

[0053] A fourth chamber S4 on the inner circumferential side of the first cylindrical region 41 and the second and third chambers S2 and S3 on the outer circumferential side of the same communicate through the second channel 411A on the top and the second channel 411B on the bottom, so that even when the inner walls of the respective membranes 10 abut against the upper and lower surfaces 413A and 413B of the first cylindrical region 41 and the areas within the abutting the upper and lower surfaces are contracted, the entire area of ​​the first to fourth chambers S1 to S4 can be used as a damping volume, and a maximum effect of reducing the pulsation can be exerted.

[0054] As previously described, in the pulsation damper 100 according to the first embodiment of the present invention, the respective membranes 10 behave in the manner described above, so that, in comparison with the conventional type of pulsation damper without the deformation suppression part 40, excessive deformation of the membranes 10 is suppressed, and this prevents a deterioration of the service life of the membranes 10.

[0055] Furthermore, by simply inserting the deformation suppression part 40 into the interior of the two membranes 10 without the need for special fastening means, the membranes 10 can be stably arranged in the correct position inside the interior, and the position does not shift even when the pulsation damper 100 is operating.

[0056] Thus, the pulsation damper with a deformation suppression effect of the membranes can be formed with an extremely simple design.

[0057] According to the foregoing description, the central curved area 13 is provided in the middle of the projecting area 12 of each membrane 10, and the annular curved area 14 is arranged on its outer circumferential area, but it is also possible to provide two or more annular curved areas with different diameters on the outer side of the central curved area 13.

[0058] Furthermore, at least one connecting hole (not shown) for connecting the front and rear sides (the upper membrane side and the lower membrane side) can be provided on the extension area 42. The weight of a deformation suppression part 40 can be reduced by providing such a connecting hole. Second embodiment

[0059] Fig. Figure 6 is a cross-sectional view in which a pulsation damper according to a second embodiment of the present invention is cut through in a central cross-section, and the view corresponds to Fig. 1, in Fig. Figure 7 is a perspective view showing the external appearance of the deformation suppression part 50, which is located in Fig. 6 is shown. As in Fig. 6 and Fig. As shown in figure 7, the same reference numbers denote identical or corresponding parts.

[0060] As in Fig. 6 and Fig. As shown in Figure 7, the shape of the deformation suppression part 50 differs from the deformation suppression part 40 according to the first embodiment.

[0061] Similar to the deformation suppression part 40, the deformation suppression part 50 is formed in an approximately ring-shaped form around the central axis O2 from an elastic material with an elasticity such as rubber, but the part 50 is further provided with a first cylindrical area (inner cylindrical area) 41, which is centered around the central axis O2 and has a predetermined width (height) in the direction of the central axis O2, and an extension area 42, which extends outwards from the central area of ​​the outer circumferential surface of the first cylindrical area 41 and has a smaller width than the first cylindrical area 41 in the direction of the central axis O2.In the deformation suppression part 50, the second cylindrical area 43, which is present in the deformation suppression part 40 according to the first embodiment, is absent, and the extension area itself extends in the outer circumferential direction of the deformation suppression part 50 and abuts against the upper and lower membranes 10A and 10B. Thus, the deformation suppression part 50, similar to the deformation suppression part 40, can be stably arranged in the space surrounded by the membranes 10.

[0062] Furthermore, a plurality of (12 in the example of Fig. 7) groove-shaped first channels 531 are formed on the outer circumferential region of the extension region 42 in the direction of the central axis O2. Similar to the first channels 431 of the first embodiment, the first channels 531 connect the first chamber S1, which is surrounded by the outer circumferential region of the extension region 42 and both membranes 10, with the second and third chambers S2 and S3, which are surrounded by the upper and lower surfaces of the extension region 42 and both membranes.

[0063] The number of first channels 431 is not limited to twelve. Furthermore, in the exemplary embodiment in Fig. 7 a second channel 411 is provided on each of the upper surface or lower surface of the first cylindrical area 41 (reference numerals 411A and 411B), but two or more channels 411 may be provided.

[0064] By using the deformation suppression part 50, which is designed as described above, even when the membranes 10 are pulled substantially inwards, the membranes abut against the upper and lower surfaces of the first cylindrical area 41 of the deformation suppression part 40 ( Fig. 8) such that the pulsation suppression effect can be ensured and excessive deformation of the upper and lower membranes can be suppressed, thereby preventing a deterioration in the service life of the membranes.

[0065] Furthermore, by simply inserting the deformation suppression part 50 into the interior of the membranes 10 without providing any special fastening means, the part 50 can be stably arranged in the correct position inside the interior without the need for special fastening means, and the position of the part will not shift even during the operation of the pulsation damper 200.

[0066] Since a second cylindrical area is not provided, the further advantage is that the weight of the deformation suppression part is reduced.

[0067] The second cylindrical area 43, described in the first embodiment, prevents the deformation suppression part 40 from being easily inserted between the two diaphragms 10 during assembly of the pulsation damper, but in the embodiment without the second cylindrical area, a certain degree of thickness is provided at the expansion area 42 to prevent the deformation suppression part 50 from being inserted during assembly. Third embodiment

[0068] Fig. Figure 9 is a perspective view of the external appearance of a deformation suppression part 60 according to a third embodiment of the present invention. Fig. 9 denotes the same reference numbers as in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. 8 identical or comparable parts.

[0069] As with the pulsation dampener that is in the Fig. 1 and Fig. As shown in Figure 6, the deformation suppression part 60 is arranged to be positioned between the upper and lower membranes 10, into which inert gas is filled, and it performs comparable functions to the deformation suppression parts 40 and 50.

[0070] The deformation suppression element 60 is formed approximately annularly around a central axis O3 from materials with elasticity such as rubber and is equipped with a first cylindrical region (inner cylindrical region) 41, which is centered around the central axis O3 and has a predetermined width (height) in the direction of the central axis O3, as well as with a plurality of extension regions 62 that extend outwards from the central region of the outer circumferential surface of the first cylindrical region 41 and have a smaller width than the first cylindrical region 41 in the direction of the central axis O3, and an extended region 63 is provided on the outer circumferential side of each extension region 62 with a smaller width than the first cylindrical region 41 in the direction of the central axis O3 and with a width (height) greater than the width of the extension regions 62 in the direction of the central axis O3. In the exemplary embodiment from Fig. 9 six extension areas 62 and six extended areas 63 are provided, and spaces 65 are formed between them.

[0071] The majority of extension areas 62 and extended areas 63 are shaped in such a way that they can be divided into several parts by predetermined distances (intervals 65 in Fig. 9) by forming a plurality of notches between the annular expansion area 42 and the second cylindrical area 43 on the outer side of the expansion area 42 and the deformation suppression part 40 in Fig. are divided into 3.

[0072] With the deformation suppression part 60, an effect similar to that of the deformation suppression parts 40 and 50 can be achieved, and the further effect of a lighter weight compared to the deformation suppression part 40 is achieved.

[0073] It is understood that the number of extension areas (62) and extended areas (63) may differ from six.

[0074] Furthermore, at least one connecting hole (not shown), which penetrates the front and rear sides, can be provided on the extension area 62. By providing such a connecting hole, the weight of the deformation suppression part 60 can be further reduced. Fourth embodiment

[0075] Fig. Figure 10 is a cross-section in which a pulsation damper according to a fourth embodiment of the present invention is cut open along a central cross-section thereof. Fig. 10 denotes the same reference numbers as in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. 9 identical or comparable parts.

[0076] Fig. Figure 10 shows a condition in which an internal pressure (charge pressure of the inert gas) and an external pressure of a pulsation damper 500 are equal, and if the pulsation damper 500 is arranged in the atmosphere (i.e., if the external pressure is lower than the internal pressure of the pulsation damper 500), a central region of the upper diaphragm 10A and a lower diaphragm 20A is expanded relative to the shape shown.

[0077] Pulsation dampeners, which are associated with the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. As described in Figure 9, the upper membrane 10A and the lower membrane 10B have identical shapes, and in the case described in Fig. The pulsation dampeners 500 shown in the diagram have different shapes for the upper and lower diaphragms. These details are described below.

[0078] First of all, the upper membrane 10A is constructed in the same way as previously described. Fig. 1 described.

[0079] Furthermore, the lower membrane 20A is shaped such that the horizontal cross-sections of the respective areas are round, by subjecting a sheet material such as a stainless steel plate to plastic deformation, such as pressing, similar to the upper membrane 10A. However, the structure of the lower membrane 20A differs from that of the upper membrane 10A in the following respects. The lower membrane 20A does not include a central curved area, but it does include an annular flange area 11, a flat area 21 parallel to the flange area, and an annular curved area 22 connecting the flange area and the flat area 21.

[0080] The concave sides of the upper diaphragm 10A and the lower diaphragm 20A are opposite each other, the deformation suppression part 40 is arranged inside the diaphragms and an inert gas is enclosed in their interior, and the flange area 11 has been subjected to full ring welding, thereby forming the pulsation damper 500.

[0081] Since the lower membrane 20 does not have a central curved area, as in Fig. As shown in Figure 10, when the internal pressure (charge pressure of the inert gas) and the external pressure of the pulsation damper 500 are equal, the lower surface of the first cylindrical area 41, which is provided on the deformation suppression part 40, is in contact with the lower diaphragm 20A, but when the pulsation damper 500 is arranged in the atmosphere, the lower diaphragm 20A is in a state in which its center is further extended than in the illustrated form, so that a gap G is formed between the deformation suppression part 40 on the side of the upper diaphragm 10A.

[0082] In the present embodiment, the shapes of the upper diaphragm 10A and the lower diaphragm 20A differ, so that they also behave differently during the operation of the pulsation damper 500.

[0083] A fuel pump and other products in which the pulsation dampener is installed have different characteristics, and to effectively suppress pulsation in such products, the diaphragm's features must be individually adapted to the product's characteristics. If the pulsation dampener is constructed with diaphragms of different shapes, as is the case in the present embodiment, it becomes possible to create an efficient pulsation dampener by selecting two types of diaphragms with different existing diaphragm types. As a result, the diaphragms do not need to be individually designed to match the characteristics of the fuel pumps, which is economically advantageous. Fifth embodiment

[0084] Fig. Figure 11 is a cross-section in which a further embodiment of the membrane used in a fifth embodiment of the present invention is cut open at a central cross-section. Fig. 11 denotes the same reference numbers as in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 to Fig. 10 identical or comparable parts. Furthermore, in Fig. 11 Gas not filled into a projecting area 30A, and a condition is shown in which a pressure on an outer wall side (projecting side) of the projecting area 30A and a pressure on an inner wall side are equal.

[0085] Similar to membranes 10 and 20, a membrane 30 of this embodiment is designed to have a round outer shape (the horizontal cross-sections of the respective areas are round), namely by plastic deformation such as pressing a metal sheet such as a stainless steel plate.

[0086] Furthermore, the membrane 30 comprises a first annular curved region 31 with a center of curvature designated by reference numeral R31C and a radius of curvature in a central cross-section designated by R31, and a second annular curved region 32 with a center of curvature designated by reference numeral R32C and a radius of curvature designated by R32, wherein a central region (ceiling region 30R) surrounded by the first annular curved region 31 has a flat shape, such that the membrane 30 has a projecting region 30A projecting in one direction and a concave region 30B on an opposite side (inner wall side of the projecting region 30A).

[0087] In the external appearance of the membrane 30, the first annular curved area 31 and the second annular curved area 32 are formed as ring-curved areas in two steps on an outer side in the radial direction of the flat ceiling area 30R.

[0088] The annular flange area 11 is formed on the outer circumference of the projecting area 30A, and the projecting area 30A projects on one side of the annular flange area 11.

[0089] The center of curvature R31C of the first annularly curved area 31 and the center of curvature R32C of the second annularly curved area 32 are located at different positions on the opposite side (inner wall side of the projecting area 30A) from the projection direction of the projecting area 30A.

[0090] Furthermore, a connecting area 30S, which connects the curved area 31 and the second annular curved area 32, is formed approximately linearly in the central cross-section and is inclined with respect to the ceiling area 30R or the flange area 11.

[0091] The membrane 30 according to the fifth embodiment forms two types of annular curved regions (the first annular curved region 31 and the second annular curved region 32) in the central cross-section. Thus, as in Fig. As shown in Figure 11, in a state where the radius of curvature R31 of the first annular curved region 31 and the radius of curvature R32 of the second annular curved region 32 have different sizes, there is no need to provide the connecting region 30S. In this case, the centers of curvature R31C and R32C are located at different positions.

[0092] If the radius of curvature R31 of the first annular curved area 31 and the radius of curvature R32 of the second annular curved area 32 have the same dimensions, a linearly inclined connection area 30S should be provided, as shown in Fig. Figure 11 shows that the centers of curvature R31C and R32C should be in different positions.

[0093] In the fifth embodiment, two annular curved areas 31 and 32 are formed on the membrane 30, but three or more annular curved areas can also be provided.

[0094] Furthermore, the membrane 30 with such a shape can replace the membranes according to the first to fourth embodiments to form the pulsation damper.

[0095] In the present invention, the shape of the membrane is not limited to the configurations described above, and any other shape can be used.

[0096] In the first to fifth embodiments, the pulsation dampener is formed by arranging the upper and lower diaphragms (i.e., the pair of diaphragms) opposite each other, arranging the deformation-suppression element inside the diaphragms, and filling them with inert gas. However, the present invention is not limited to this example, and the pulsation dampener can be formed by arranging a single flat, plate-like part (such as a flat metal plate) and a diaphragm opposite each other, arranging the deformation-suppression element inside them, and filling them with inert gas.

[0097] In this case, the shape of the first cylindrical area or its position relative to the extension area (position of the first cylindrical area in the vertical direction) can be arbitrarily modified so that the deformation-suppression element is not displaced in the position between the flat, plate-like part and the membrane; in other words, so that the deformation-suppression element does not abut or come into close contact with the flat, plate-like part and the inner wall of the membrane. Furthermore, if the second cylindrical area and the extension area are provided, the shapes of the second cylindrical area and the extension area 63, or their positions relative to the extension area, can be arbitrarily modified. Sixth embodiment

[0098] Fig. 12 is a cross-sectional view in which a pulsation damper according to a sixth embodiment of the present invention is cut open at a central cross-section, which provides a view corresponding to Fig. 1 is, and Fig. Figure 13 is a perspective view showing an external appearance of a deformation suppression part 70 according to Fig. 12 shows. In the Fig. 12 and Fig. 13 denotes the same reference numbers as in the Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5 the same or equivalent parts.

[0099] As in Fig. 12 and Fig. As shown in Figure 13, in the sixth embodiment the shape of the deformation suppression part 70 differs from the deformation suppression part 40 according to the first embodiment. Specifically, the deformation suppression part 70 is essentially ring-shaped around the central axis O2 and is made of an elastic material with an elasticity similar to that of rubber, and in addition to the first cylindrical area (inner cylindrical area) 41, the expansion area 42, and the second cylindrical area (outer cylindrical area) 43, it has... Fig. 1 or Fig. 3, the deformation suppression part 70 has on the extension area 42 a third cylindrical area (middle cylindrical area) 45 which is centered around the central axis O2 and projects in the direction O2 of the central axis with a slightly greater width (height) than the first cylindrical area 41, and an annular concave area 44 is formed between the first cylindrical area 41 and the third cylindrical area 45.

[0100] Similar to the first embodiment, the outer circumferential surface of the second cylindrical region 43 abuts the upper membrane 10A and the lower membrane 10B. As a result, the deformation suppression element 70 is stably arranged within the space surrounded by the two membranes 10, similar to the deformation suppression element 40.

[0101] By using the deformation suppression part 70 with such a shape, in a state in which no external pressure acts, as in Fig. As shown in Figure 12, spaces G1 and G2 are formed between the first and third cylindrical areas 41,45 and the upper and lower membranes 10A and 10B.

[0102] However, if the upper and lower membranes 10A and 10B are pressed and deformed, as in Fig. As shown in Figure 14, the deformation suppression part 70 strikes the inner surface of the membrane at two points (at the first cylindrical area 41 and at the third cylindrical area 45).

[0103] This increases the contact area between the membranes 10A and 10B and the deformation suppression part 70, and a stress exerted on the membrane can be reduced even when a high external pressure is applied.

[0104] Since the annular curved area 44 is formed between the first cylindrical area 41 and the third cylindrical area 45, a fifth space S5 is formed in a state in which the membranes 10A and 10B abut against the deformation suppression part 70.

[0105] This allows the volume of inert gas that needs to be filled into the interior of a pulsation damper 600 to be reduced, while increasing the contact area between the membranes 10A and 10B and the deformation suppression part 70.

[0106] The sixth embodiment shows an example of a case in which first and third cylindrical areas are formed in the radial direction of the deformation suppression part 70, but there may also be three or more cylindrical areas located in the annular concave area.

[0107] Furthermore, similar to the deformation suppression part 40 shown in the first embodiment, a plurality of groove-shaped first channels can be formed in the direction of the central axis O2 on the outer circumferential region of the second cylindrical region 43.

[0108] Furthermore, a groove-shaped second channel, connecting the inside or outside of the cylindrical areas with the annular curved area 44, can be formed on an upper surface or a lower surface of the first cylindrical area 41 and the third cylindrical area 45.

[0109] When the deformation suppression part 70 is used with the shape described above, similar to the first embodiment, even when the membranes 10 are pulled strongly inwards, the membranes 10 abut against the upper and lower surfaces of the first cylindrical area 41 and the third cylindrical area 45 of the deformation suppression part 40 ( Fig. 14), so that a pulsation suppression effect is ensured and excessive deformation of the upper and lower membranes can be suppressed, thereby preventing impairment of the membrane lifetime.

[0110] Here, the height of the third cylindrical section 45 of the deformation suppression part 70 is greater than the height of the first cylindrical section 41, as shown in Fig. 14 shown, and a deflection of the membranes 10A and 10B can be large near the central curved area 13, and the pulsation damper 600 can be used in a system in which a higher external pressure is applied.

[0111] The deformation suppression part 70 includes a third cylindrical area 45, which is dimensioned higher than the first cylindrical area 41, so that when the membranes 10 are pulled strongly inwards, the third cylindrical area 45 and the first cylindrical area 41 can strike against the membranes 10 simultaneously, and the deformation suppression effect on the membranes 10 is strong.

[0112] If the height of the first cylindrical section 41 and the third cylindrical section 45 are the same, or if the height of the first cylindrical section 41 is higher than that of the third cylindrical section 45, the deformation of the middle curved section 13 may be provided as a priority over a deformation of the annular curved section 14.

[0113] The deformation suppression effect can be further improved by modifying the shapes of the respective ends 41a and 45a (see Fig. 12) of the first cylindrical area 41 and of the third cylindrical area 45 (the areas that abut the membrane) are designed as R-shaped or frustoconical, so that they abut the membranes 10 in a planar fashion from the initial state. Seventh embodiment

[0114] The pulsation dampers described above position the deformation suppression element inside the diaphragms. The deformation suppression element controls the degree of contraction, causing the diaphragms to retract inwards.

[0115] In contrast, a seventh embodiment of the present invention not only suppresses deformation in a state in which the membranes are pulled inwards, but also suppresses deformation in a state in which the membranes are expanded outwards.

[0116] Fig. Figure 15 is a cross-section showing a state in which a pulsation damper according to a seventh embodiment of the present invention is cut open in the center of a cross-section of the pulsation damper.

[0117] A pulsation dampener 900 according to Fig. 15 comprises a covering designed to suppress outward deformation of membranes and which is located on the upper and lower sides of the pulsation damper 100 in Fig. 1 is appropriate.

[0118] That is, the pulsation damper 900 is constructed such that flange areas 11 and 11 of the diaphragms 10A and 10B are located between a cover flange area 915, which is formed on an outer circumferential area of ​​an upper cover 910, and a cover flange area 925, which is formed on an outer circumferential area of ​​a lower cover 920, and the located area is welded by laser welding or the like.

[0119] The upper cover 910 and the lower cover 920 are each formed by pressing a sheet of metal, such as a steel plate.

[0120] The upper cover 910 is provided with the cover flange area 915, which is formed on the outer circumferential area, and a stepped area 911 is arranged on an inner side thereof. An opening 913 is formed in the center of an upper surface of the stepped area 911, and a plurality of claws 912 are cut out at the edge of the opening 913 and extend from it.

[0121] The lower cover 920 is equipped with a cover flange area 925 formed on its outer circumferential edge, a first stepped area 921 is provided on its inner surface, and a second stepped area 922 is provided on the inner surface of the first stepped area 921. A plurality of round openings 924 are formed on a side surface of the first stepped area 921, and a large-diameter opening 923 is formed on a lower surface of the second stepped area 922.

[0122] The pulsation damper 900, which is covered by these covers 910 and 920, is arranged within the pressure chamber of a fuel pump or the like such that the opening 923 is located at the top, and by pressing down the claws 912 by suitable means which are arranged on the upper area, the pulsation damper 900 can be installed within the fuel pump and the like by a simple process without damaging the diaphragms 10.

[0123] If, during operation of the pulsation damper 900, the diaphragm 10 is excessively expanded by a pulsation of external pressure, the diaphragm 10 abuts a ceiling area 912 of the upper cover 910, and the deformation of the diaphragm is limited. In the present embodiment, this suppresses deformation both when the diaphragm 10 is excessively contracted and when it is expanded, thus reducing fatigue of the diaphragm 10, preventing a shortened service life, avoiding plastic deformation of the diaphragm, and ensuring that the pulsation absorption effect of the diaphragm is not impaired.

[0124] Furthermore, since the diaphragms 10A and 10B are covered by covers 910 and 920, the diaphragms are not damaged when the pulsation damper 900 is arranged inside the fuel pump or the like, so that the arrangement further contributes to preventing impairment of the service life of the pulsation damper.

[0125] It is also possible that the lower membrane 10B abuts against the lower cover 920 to suppress deformation of the membrane 10b, in a condition in which the lower membrane 10B expands excessively. List of reference symbols 100, 200, 500, 600, 900 Pulsation dampeners 10, 20, 30 Membran 10A upper membrane 10B, 20A lower membrane 40, 50, 60, 70 Deformation suppression part 41 first cylindrical area (inner cylindrical area) 42, 62 Extension area 43 second cylindrical area (outer cylindrical area) 44 ring-shaped concave area 45 third cylindrical area (middle cylindrical area) 63 extended area 431, 531 first channel 411 second channel

Claims

[1] Pulsation dampener (100), comprising: an upper membrane (10A); a lower membrane (10B, 20A) designed to form a sealed space with the upper membrane (10A) at a predetermined pressure, into which an inert gas is filled; and a deformation suppression part (40, 50, 60, 70) formed from an elastic material and comprising an inner cylindrical region (41), and an extension region (42, 62) extending from a central region on an outer circumferential surface of the inner cylindrical region (41), such that the extension region (42, 62) extends outwards from a central axis of the inner cylindrical region (41), wherein the deformation suppression part (40, 50, 60, 70) is arranged within the sealed space such that an outer circumference of the expansion area (42, 62) abuts inner walls of the upper membrane (10A) and the lower membrane (10B, 20A), and wherein a first channel (431, 531) is formed on an outer circumferential region of the extension region (42, 62), which connects a first space, surrounded by an outer circumferential surface of the extension region (42, 62), the upper membrane (10A) and the lower membrane (10B, 20A), with a second space on the side of the extension region (42, 62) which is the side of the extension region (42, 62) to the upper membrane (10A), and a third space on the side of the extension region (42, 62) which is the side of the extension region (42, 62) to the lower membrane (10B, 20A). [2] Pulsation damper (100) according to claim 1, wherein the outer circumference of the expansion area (42, 62) of the deformation suppression part (40, 50, 60, 70) comprises an outer cylindrical area (43) extending in the direction of a central axis of the pulsation damper (100), wherein a top and a bottom of the outer cylindrical area (43) abut against the inner walls of the upper diaphragm (10A) and the lower diaphragm (10B, 20A). [3] Pulsation damper (100) according to one of claims 1 or 2, wherein in an unloaded state the inner cylindrical area (41) forms a predetermined space between at least either the upper diaphragm (10A) or the lower diaphragm (10B, 20A). [4] Pulsation damper (100) according to one of claims 1 to 3, in which a second channel (411) connecting an inside with an outside of the inner cylindrical region (41) is formed at least either on a side associated with the upper diaphragm (10A) or the side associated with the lower diaphragm (10B, 20A) of the inner cylindrical region (41). [5] Pulsation damper (100) according to one of claims 1 to 4, in which at least either a contact area of ​​the outer circumferential area of ​​the expansion area (42, 62) with the upper diaphragm (10A) or a contact area of ​​the outer circumferential area of ​​the expansion area (42, 62) with the lower diaphragm (10B, 20A) is formed on a curved surface. [6] Pulsation damper (100) according to claim 5, wherein a radius of curvature of the curved surface is either equal to a radius of curvature of an inner wall of the upper membrane (10A) in contact with the curved surface or equal to a radius of curvature of an inner wall of the lower membrane (10B, 20A) in contact with the curved surface. [7] Pulsation damper (100) according to one of claims 1 to 6, in which a central cylindrical area (45) which projects in the direction of a central axis of the deformation suppression part (40, 50, 60, 70) is further provided on the expansion area (42, 62). [8] Pulsation damper (100) according to claim 7, wherein the expansion area (42, 62) has a plurality of the central cylindrical areas (45) which are formed at a predetermined distance. [9] Pulsation damper (100) according to any one of claims 1 to 8, wherein when a pressure applied to an outer surface and a pressure applied to an inner surface are equal, a central region of at least either the upper diaphragm (10A) or the lower diaphragm (10B, 20A) is configured to project outwards. [10] Pulsation damper (100) according to any one of claims 1 to 9, wherein the pulsation damper (100) further comprises an upper cover (910) and a lower cover (920) configured to enclose the upper diaphragm (10A) and the lower diaphragm (10B, 20A). [11] Pulsation damper (100) according to any one of claims 1 to 10, wherein the expansion area (42, 62) comprises a hole or notch which connects the side to the upper diaphragm (10A) with the side to the lower diaphragm (10B, 20A). [12] Pulsation dampener (100), comprising: a membrane (10, 20 30); a plate-like element designed to form a sealed space with a predetermined pressure with the membrane (10, 20, 30) into which an inert gas is filled; and a deformation suppression part (40, 50, 60, 70) formed from an elastic material, comprising an inner cylindrical region (41) and an extension region (42, 62) extending from a central region onto an outer circumferential region of the inner cylindrical region (41), such that the extension region (42, 62) extends outwards from a central axis of the inner cylindrical region (41), wherein the deformation suppression part (40, 50, 60, 70) is arranged within the sealed space such that the deformation suppression part (40, 50, 60, 70) abuts against inner walls of the membrane (10, 20, 30) and the plate-like element, wherein a second channel (411) connecting an inside with an outside of the inner cylindrical region (41) is formed at least either on one side associated with the membrane (10, 20, 30) or on the side of the inner cylindrical region (41) associated with the plate-like element.

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