Pressurizing corrugated pipe assembly structure for high-pressure fuel pump

Abstract

The utility model belongs to the field of fuel pumps, and provides a pressurizing corrugated pipe assembly structure for a high-pressure fuel pump, which comprises a sleeve, a plunger, a corrugated pipe, a sealing component and a bottom sleeve. Wherein a flange coaxial with the sleeve is formed on the outer surface of the sleeve; the plunger is connected into the sleeve in a sliding mode and used for sealing a port in one side of the sleeve. The corrugated pipe and the sleeve are coaxially arranged at an interval; the sealing assembly comprises an inner sleeve arranged on the sleeve in a sleeving mode and an outer ring connected to the flange, the inner sleeve is arranged between the corrugated pipe and the sleeve in a cushioned mode and abuts against the flange, and the pipe wall of the corrugated pipe is clamped between the inner sleeve and the outer ring so that the corrugated pipe and the sleeve can be in sealed connection; the bottom sleeve is embedded in the corrugated pipe and used for sealing a port of the side, away from the flange, of the corrugated pipe.

Description

Technical Field

[0001] This application belongs to the field of fuel pumps, and particularly relates to a pressure boosting bellows assembly structure for a high-pressure fuel pump. Background Technology

[0002] As the core sealing and pressure regulating component in a high-pressure fuel pump, the bellows assembly plays a crucial role in pumping fuel, and its performance directly determines the sealing reliability of the fuel pump and the stability of fuel supply under high-pressure conditions.

[0003] Traditional bellows assemblies typically use hot-working methods (such as welding or high-temperature fusion) to fix the bellows ends to adjacent components in the sealing connection process. However, high-temperature treatment can easily cause changes in the crystal structure of the bellows metal, reducing its elastic modulus and fatigue resistance. Under long-term high-pressure alternating loads, it is prone to local deformation, microcracks, or even fracture, leading to seal failure. This not only causes premature damage to the bellows itself but also triggers internal leakage and abnormal pressure fluctuations in the fuel pump, ultimately resulting in insufficient pumping pressure and reduced fuel supply stability. Therefore, it is necessary to solve the above-mentioned technical problems. Utility Model Content

[0004] The purpose of this application is to provide a pressure-boosting bellows assembly structure for a high-pressure fuel pump, so as to solve the technical problem of poor fuel supply stability in the prior art.

[0005] To achieve the above objectives, the technical solution adopted in this application is: to provide a high-pressure fuel pump booster bellows assembly structure, comprising:

[0006] The sleeve has a flange formed on its outer surface that is coaxial with itself.

[0007] A plunger, slidably connected inside the sleeve and used to seal one side port of the sleeve;

[0008] A bellows is coaxially spaced from the sleeve, with one end of the sleeve away from the plunger extending into the bellows;

[0009] A sealing assembly includes an inner sleeve fitted onto the sleeve and an outer ring connected to the flange, the inner sleeve being disposed between the bellows and the sleeve and abutting against the flange, and the wall of the bellows being clamped between the inner sleeve and the outer ring to form a sealing connection between the bellows and the sleeve.

[0010] A bottom sleeve is fitted inside the bellows and is used to seal the side of the bellows away from the flange.

[0011] Optionally, the outer wall of the inner sleeve forms a tapered section along its own axial direction, and the bellows forms a tapered flare adapted to the tapered section of the inner sleeve with the tapered flare facing the flange.

[0012] Optionally, the outer ring is welded to the flange.

[0013] Optionally, the sealing assembly further includes a sealing ring coaxially connected to the outer ring, wherein a groove is formed on the outer ring for receiving the sealing ring.

[0014] Optionally, the high-pressure fuel pump booster bellows assembly structure further includes a guide plate and a guide rod;

[0015] The guide plate is connected to the end of the sleeve and forms a flow hole for connecting the bellows and the sleeve. The end of the guide rod is connected to the bottom sleeve and slidably connected to the guide plate. The sliding direction of the guide rod relative to the guide plate is parallel to the axial direction of the bellows.

[0016] Optionally, the flow holes are distributed radially along the guide rod on opposite sides of the guide rod.

[0017] Optionally, a fluid replenishment channel is formed inside the plunger, and the two ends of the fluid replenishment channel are respectively used to communicate with the sleeve and the external fluid supply device;

[0018] The high-pressure fuel pump booster bellows assembly also includes a one-way valve that can be opened by a pressure difference. The one-way valve is located on the plunger and enables one-way communication between the fluid replenishment channel and the sleeve.

[0019] Optionally, the replenishment channel includes a vertical flow channel coaxial with the plunger and a transverse flow channel perpendicularly connected to the vertical flow channel;

[0020] The one-way valve is located in the vertical flow channel.

[0021] Optionally, the transverse flow channel extends through the plunger.

[0022] Optionally, the plunger forms a conical hole with its large end facing the bottom sleeve in the middle part of the replenishment channel, and the one-way valve includes a steel ball for abutting against the side wall of the conical hole, a pin transversely placed in the replenishment channel, and a small spring coaxially arranged with the plunger.

[0023] The pin is located near the large end of the tapered hole and is used to restrict the steel ball from leaving the tapered hole. The two ends of the small spring abut against the steel ball and the plunger, respectively.

[0024] The beneficial effects of the high-pressure fuel pump booster bellows assembly structure provided in this application are as follows: Compared with the prior art, in the high-pressure fuel pump booster bellows assembly structure provided in this application, the inner sleeve coaxially fitted on the sleeve and the outer ring connected to the flange clamp the pipe wall of the bellows used to form one side port between the two and form a sealed connection between the bellows and the sleeve. The other side port of the bellows is sealed by the bottom sleeve embedded inside the bellows. This not only can a good sealing effect be formed between the bellows and the sleeve, but also the bellows can form a sealed connection with the sleeve without heat treatment. This significantly extends the service life of the bellows and is also conducive to improving the fuel supply stability of the fuel pump, which is far superior to the prior art. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of the high-pressure fuel pump booster bellows assembly in this embodiment of the application;

[0027] Figure 2 This is a cross-sectional structural diagram of the high-pressure fuel pump booster bellows assembly in the embodiments of this application;

[0028] Figure 3 This is a schematic diagram of the structure of the high-pressure fuel pump booster bellows assembly after it has been installed into the fuel pump in this embodiment of the application.

[0029] The reference numerals in the figures are as follows: 101, sleeve; 102, flange; 103, plunger; 104, bellows; 105, inner sleeve; 106, outer ring; 107, bottom sleeve; 108, tapered flare; 109, sealing ring; 110, guide plate; 111, guide rod; 112, flow hole; 130, replenishment channel; 131, vertical flow channel; 132, horizontal flow channel; 140, check valve; 141, tapered hole; 142, steel ball; 143, pin; 144, small spring; 201, drive rod; 202, cover; 203, medium cavity; 204, pump body; 205, first check valve of the pump; 206, oil passage; 207, second check valve of the pump; 208, booster chamber; 209, large spring. Detailed Implementation

[0030] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0031] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0032] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0034] Please refer to the following: Figures 1 to 3 The present application provides a description of a high-pressure fuel pump booster bellows assembly structure. This high-pressure fuel pump booster bellows assembly structure includes a sleeve 101, a plunger 103, a bellows 104, a sealing assembly, and a bottom sleeve 107. Wherein:

[0035] A flange 102, coaxial with itself, is formed on the outer surface of the sleeve 101; a plunger 103 is slidably connected inside the sleeve 101 and is used to seal one side port of the sleeve 101; a bellows 104 is coaxially spaced from the sleeve 101, with one end of the sleeve 101 away from the plunger 103 extending into the bellows 104, thus, in this embodiment, the flange 102 is located in the middle of the sleeve 101; the sealing assembly includes an inner sleeve 105 fitted on the sleeve 101 and an outer ring 106 connected to the flange 102, the inner sleeve 105 is placed between the bellows 104 and the sleeve 101 and abuts against the flange 102, the wall of the bellows 104 is clamped between the inner sleeve 105 and the outer ring 106 to form a sealed connection between the bellows 104 and the sleeve 101; a bottom sleeve 107 is embedded inside the bellows 104 and is used to seal the side port of the bellows 104 away from the flange 102. In this embodiment, the plunger 103 is used to move inside the sleeve 101 to change the internal pressure of the sleeve 101, thereby enabling the bellows 104 to expand or contract to achieve the purpose of pumping high-pressure fuel.

[0036] According to the structure provided in this embodiment, in the high-pressure fuel pump booster bellows assembly structure provided in this embodiment, the inner sleeve 105 coaxially fitted on the sleeve 101 and the outer ring 106 connected to the flange 102 clamp the pipe wall of the bellows 104, which forms one side port, between the two and form a sealed connection between the bellows 104 and the sleeve 101. The other side port of the bellows 104 is sealed by the bottom sleeve 107 embedded inside the bellows 104. This not only allows a good sealing effect between the bellows 104 and the sleeve 101, but also allows the bellows 104 to form a sealed connection with the sleeve 101 without heat treatment. This significantly extends the service life of the bellows 104 and also helps to improve the fuel supply stability of the fuel pump, which is far superior to the prior art.

[0037] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3 The outer wall of the inner sleeve 105 forms a tapered section along its own axial direction, and the bellows 104 forms a tapered flare 108 adapted to the tapered section of the inner sleeve 105, with the tapered flare 108 facing the flange 102. According to the structure provided in the embodiment, the structure of the bellows 104 adapted to the tapered flare 108 of the tapered section of the inner sleeve 105 can form a better sealing effect between the bellows 104 and the inner sleeve 105. Here, it can be understood that the inner wall of the outer ring 106 is provided with a tapered hole section that corresponds to and matches the tapered section of the inner sleeve 105. In this way, when the tapered flare 108 of the bellows 104 is fitted onto the tapered section of the inner sleeve 105 and pressed into the tapered hole section of the outer ring 106, a self-tightening seal is formed, which is beneficial to further improve the fuel supply stability of the fuel pump.

[0038] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3 The outer ring 106 is welded to the flange 102. According to the structure provided in the embodiment, the outer ring 106 welded to the flange 102 allows the inner sleeve 105 to be pressed and fixed against the corresponding end face of the flange 102, thereby forming a reliable fixed sealing connection with the bellows 104 and sealing the ports of the inner sleeve 105 and the bellows 104 inside the outer ring 106. This results in a better sealing effect between the bellows 104 and the sleeve 101. Here, laser welding is preferably used to effectively avoid heat transfer to the bellows 104 during welding, ensuring the original performance of the bellows 104. This is beneficial for further improving the fuel supply stability of the fuel pump.

[0039] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3 The sealing assembly also includes a sealing ring 109 coaxially connected to the outer ring 106, with a groove formed on the outer ring 106 for accommodating the sealing ring 109. According to the structure provided in the embodiment, the sealing ring 109 fitted onto the outer ring 106 can create a better sealing effect between the bellows assembly structure and the target component in this embodiment, which is beneficial for further improving the fuel supply stability of the fuel pump.

[0040] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3 The high-pressure fuel pump booster bellows assembly also includes a guide plate 110 and a guide rod 111. The guide plate 110 is connected to the end of the sleeve 101 and forms a flow hole 112 for connecting the bellows 104 and the sleeve 101. The end of the guide rod 111 is connected to the bottom sleeve 107 and slidably connected to the guide plate 110. The sliding direction of the guide rod 111 relative to the guide plate 110 is parallel to the axial direction of the bellows 104. According to the structure provided in the embodiment, the guide rod 111 slidably connected to the guide plate 110 can improve the deformation stability of the bellows 104, which is beneficial to further improve the fuel supply stability of the fuel pump.

[0041] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3 The flow holes 112 are radially distributed on opposite sides of the guide rod 111. According to the structure provided in the embodiment, the flow holes 112 provided on both sides of the guide rod 111 can make the liquid medium inside the bellows 104 have more uniform flow, which is beneficial to further improve the fuel supply stability of the fuel pump.

[0042] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3The plunger 103 has a fluid replenishment channel 130 inside, with its two ends connected to the sleeve 101 and an external fluid supply device, respectively. The high-pressure fuel pump's booster bellows assembly also includes a one-way valve 140 that can be opened by a pressure difference. The one-way valve 140 is mounted on the plunger 103 and allows one-way communication between the fluid replenishment channel 130 and the sleeve 101. According to the structure provided in the embodiment, after prolonged operation, wear and leakage between the plunger 103 and the sleeve 101 cause a drop in internal pressure between the sleeve 101 and the bellows 104. The one-way valve 140, which opens by the pressure difference, allows the fluid replenishment channel 130 to open and connect with the sleeve 101. This allows the external fluid supply device to replenish the fluid medium inside the sleeve 101, ensuring a constant fluid pressure inside the sleeve 101. This further improves the fuel supply stability of the fuel pump.

[0043] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3 The fluid replenishment channel 130 includes a vertical flow channel 131 coaxial with the plunger 103 and a transverse flow channel 132 perpendicularly connected to the vertical flow channel 131; a one-way valve 140 is disposed in the vertical flow channel 131. According to the structure provided in the embodiment, since the vertical flow channel 131 is coaxial with the plunger 103, disposing of the one-way valve 140 in the vertical flow channel 131 can improve the operational stability of the one-way valve 140, which is beneficial to further improving the fuel supply stability of the fuel pump.

[0044] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3 The transverse flow channel 132 penetrates the plunger 103. According to the structure provided in the embodiment, the transverse flow channel 132 penetrating the plunger 103 can provide higher fluid replenishment efficiency, which is beneficial to further improve the fuel supply stability of the fuel pump.

[0045] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 3The plunger 103 forms a conical hole 141 with its large end facing the bottom sleeve 107 in the middle part of the replenishment channel 130. The one-way valve 140 includes a steel ball 142 for abutting against the side wall of the conical hole 141, a pin 143 placed horizontally in the replenishment channel 130, and a small spring 144 coaxially arranged with the plunger 103. The pin 143 is close to the large end of the conical hole 141 and is used to restrict the steel ball 142 from disengaging from the conical hole 141. The two ends of the small spring 144 abut against the steel ball 142 and the plunger 103, respectively. According to the structure provided in the embodiment, when the internal liquid pressure of the sleeve 101 is insufficient, the small spring 144 can push the steel ball 142 away from the conical hole 141, thus opening the one-way valve 140; when the internal pressure of the sleeve 101 is greater than the elastic force of the small spring 144, the steel ball 142 can abut against the side wall of the conical hole 141 and close the one-way valve 140, thus realizing the automatic replenishment of the liquid inside the sleeve 101, which is beneficial to further improve the fuel supply stability of the fuel pump.

[0046] Key references Figure 3After the bellows assembly of this application is installed on the pump body 204, a booster chamber 208 is formed between the bellows 104 and the pump body 204. The plunger 103 is located outside the medium cavity 203 formed by the pump body 204 and the cover 202. The medium cavity 203 is filled with a liquid medium such as machine oil with a set pressure and viscosity. During operation, the drive rod 201 (usually controlled by a cam mechanism or eccentric shaft mechanism) used to drive the plunger 103 to move forward pushes the plunger 103 forward, squeezing the liquid medium in the sleeve 101. The pressure is forced into the bellows 104, causing it to deform and grow. This reduces the volume of the booster chamber 208, allowing the fuel inside to be pumped out under pressure through the oil passage 206 and the pump's first check valve 205. At this time, the pump's second check valve 207 automatically closes. When the drive rod 201 retracts, causing the plunger 103 to retract, the bellows 104 elastically retracts, squeezing the liquid medium inside back into the sleeve 101. This increases the volume of the booster chamber 208, creating negative pressure. At this time, the pump's second check valve 207, connected to the fuel tank, automatically opens, and the pump's first... The one-way valve 205 automatically closes, and fuel enters the booster chamber 208 through the second one-way valve 207 and oil passage 206, thus completing the pressurization pumping of fuel. In this embodiment, a large spring 209 is also fitted outside the plunger 103 to ensure timely retraction and reset of the plunger 103 when the drive rod 201 retracts. The installation method of the large spring 209 can adopt existing technology. After prolonged operation, wear may occur between the plunger 103 and the sleeve 101, leading to leakage of the liquid medium inside the sleeve 101. The liquid medium will slowly leak along the sliding mating surface between the plunger 103 and the sleeve 101, resulting in insufficient liquid medium in the sleeve 101. When this happens, after the plunger 103 retracts and resets, a negative pressure greater than the elastic force of the small spring 144 will be generated inside the sleeve 101, causing the small spring 144 to push the steel ball 142 away from the conical hole 141. At this time, the liquid medium in the medium cavity 203 will be sucked into the sleeve 101 to replenish it, thereby ensuring that the liquid medium in the sleeve 101 is maintained at the set value, thus maintaining the stability of each pumping operation.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pressure-boosting bellows assembly structure for a high-pressure fuel pump, characterized in that, include: The sleeve (101) has a flange (102) formed on its outer surface that is coaxial with itself. A plunger (103) is slidably connected inside the sleeve (101) and is used to seal one side port of the sleeve (101); A bellows (104) is coaxially spaced from the sleeve (101), and one end of the sleeve (101) away from the plunger (103) extends into the bellows (104). The sealing assembly includes an inner sleeve (105) fitted onto the sleeve (101) and an outer ring (106) connected to the flange (102). The inner sleeve (105) is placed between the bellows (104) and the sleeve (101) and abuts against the flange (102). The wall of the bellows (104) is clamped between the inner sleeve (105) and the outer ring (106) to form a sealing connection between the bellows (104) and the sleeve (101). The bottom sleeve (107) is embedded inside the bellows (104) and is used to seal the side port of the bellows (104) away from the flange (102).

2. The high-pressure fuel pump booster bellows assembly structure as described in claim 1, characterized in that: The outer wall of the inner sleeve (105) forms a tapered section along its own axial direction, and the bellows (104) forms a tapered flare (108) adapted to the tapered section of the inner sleeve (105) and the tapered flare (108) faces the flange (102).

3. The high-pressure fuel pump booster bellows assembly structure as described in claim 2, characterized in that: The outer ring (106) is welded to the flange (102).

4. The high-pressure fuel pump booster bellows assembly structure as described in claim 3, characterized in that: The sealing assembly also includes a sealing ring (109) coaxially connected to the outer ring (106), and a groove is formed on the outer ring (106) for receiving the sealing ring (109).

5. The high-pressure fuel pump booster bellows assembly structure as described in claim 1, characterized in that: The high-pressure fuel pump booster bellows assembly also includes a guide plate (110) and a guide rod (111). The guide plate (110) is connected to the end of the sleeve (101) and forms a flow hole (112) for connecting the bellows (104) and the sleeve (101). The end of the guide rod (111) is connected to the bottom sleeve (107) and is slidably connected to the guide plate (110). The sliding direction of the guide rod (111) relative to the guide plate (110) is parallel to the axial direction of the bellows (104).

6. The high-pressure fuel pump booster bellows assembly structure as described in claim 5, characterized in that: The flow holes (112) are distributed radially along the guide rod (111) on opposite sides of the guide rod (111).

7. The high-pressure fuel pump booster bellows assembly structure as described in claim 1, characterized in that: The plunger (103) forms a liquid replenishment channel (130) inside, and the two ends of the liquid replenishment channel (130) are respectively used to communicate with the sleeve (101) and the external liquid supply device; The high-pressure fuel pump booster bellows assembly also includes a one-way valve (140) that can be opened by a pressure difference. The one-way valve (140) is disposed on the plunger (103) and enables one-way communication between the fluid replenishment channel (130) and the sleeve (101).

8. The high-pressure fuel pump booster bellows assembly structure as described in claim 7, characterized in that: The replenishment channel (130) includes a vertical flow channel (131) coaxial with the plunger (103) and a transverse flow channel (132) vertically connected to the vertical flow channel (131). The one-way valve (140) is disposed in the vertical flow channel (131).

9. The high-pressure fuel pump booster bellows assembly structure as described in claim 8, characterized in that: The transverse flow channel (132) penetrates the plunger (103).

10. The high-pressure fuel pump booster bellows assembly structure as described in claim 7, characterized in that: The plunger (103) forms a conical hole (141) with its large end facing the bottom sleeve (107) in the middle part of the replenishment channel (130). The one-way valve (140) includes a steel ball (142) for abutting against the side wall of the conical hole (141), a pin (143) transversely placed in the replenishment channel (130), and a small spring (144) coaxially arranged with the plunger (103). The pin (143) is close to the large end of the tapered hole (141) and is used to restrict the steel ball (142) from disengaging from the tapered hole (141). The two ends of the small spring (144) abut against the steel ball (142) and the plunger (103) respectively.

Images