Pressure sensor for fuel tank system and fuel tank system
By designing a pressure sensor that integrates fuel steam monitoring and leak detection functions, the complexity and cost of fuel tank systems in the prior art are solved, and a more efficient and economical system monitoring effect is achieved.
Patent Information
- Application Number
- CN202510088412.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-05-09
AI Technical Summary
In the prior art, fuel steam monitoring and leakage detection of fuel tank systems require the use of two separate pressure sensors, resulting in increased system complexity and cost.
A pressure sensor for a fuel tank system is designed, including a housing, a pressure introduction channel, a first and a second pressure sensitive element, and the electronic module assembly includes a substrate, a pressure via and a signal processing circuit to achieve the function of simultaneously monitoring fuel steam pressure and leakage.
Through this pressure sensor, the fuel tank system can realize fuel steam pressure monitoring and leakage detection respectively in leak measurement and normal working conditions, reducing system cost and complexity.
Smart Images
Figure CN119957357A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of automobile technology, and in particular to a pressure sensor for a fuel tank system and a fuel tank system. Background Art
[0002] In a passenger car, the engine fuel system usually includes a fuel tank, a fuel pump, a filter, a distribution pipe, a pressure regulator and a fuel injector. Since the evaporation of the fuel in the fuel tank generates oil vapor, it can be adsorbed by an activated carbon adsorption tank and supplied to the engine for use under certain conditions, while avoiding discharge into the environment. The fuel tank and the activated carbon adsorption tank are usually equipped with separate pressure sensors, and the pressure sensor installed on the fuel tank is used to monitor the vapor pressure in the fuel tank. Another pressure sensor is used to measure the leakage of the fuel tank system, including an air valve installed on the fuel tank for inhaling air from the environment when the pressure in the fuel tank is insufficient, and a steam valve installed on the fuel tank for discharging steam when the pressure in the fuel tank is too high. When it is necessary to monitor the leakage of the fuel tank system, a negative pressure source (such as an engine) or a positive pressure source can be used to make the pressure in the fuel tank system form a negative pressure or a positive pressure, and then the sensor can be used to monitor the pressure change rate within a certain period of time to determine the sealing of the fuel tank system. Since these two sensors are powered and transmitted separately, there is the possibility of further integration. Summary of the invention
[0003] In view of the deficiencies in the prior art, the present application provides a pressure sensor for a fuel tank system to simultaneously meet the requirements of fuel vapor monitoring and leak detection.
[0004] To achieve the above objectives, the present application provides the following technical solution: a pressure sensor for a fuel tank system, comprising:
[0005] A housing having a pressure introduction passage connected to the interior of the housing;
[0006] Two pressure-sensitive elements, a first pressure-sensitive element and a second pressure-sensitive element, are sealedly connected to one end of the inner side of the pressure-introducing passage;
[0007] Wherein, the measurement accuracy of the first pressure sensitive element is higher than the measurement accuracy of the second pressure sensitive element.
[0008] Preferably, it also includes an electronic module assembly, which includes a substrate that extends generally laterally and is sealed to one end of the inner side of the pressure introduction channel, and is provided with two pressure through holes, a first pressure through hole and a second pressure through hole, which are connected to the pressure introduction channel; the first pressure sensitive element is sealed at one end of the first pressure through hole away from the pressure introduction channel, and the second pressure sensitive element is sealed at one end of the second pressure through hole away from the pressure introduction channel.
[0009] Preferably, a signal processing circuit electrically connected to the two pressure sensitive elements through leads is disposed on a surface of the substrate at a side away from the pressure introduction channel.
[0010] Preferably, it also includes an electronic module assembly, which includes a substrate that extends generally laterally and is sealed to one end of the inner side of the pressure introduction channel, and is provided with a first pressure through hole and a second pressure through hole that are connected to the pressure introduction channel; the first pressure sensitive element is sealed at one end of the first pressure through hole close to the pressure introduction channel, and the second pressure sensitive element is sealed at one end of the second pressure through hole close to the pressure introduction channel.
[0011] Preferably, a signal processing circuit is provided on the surface of the substrate on the side away from the pressure introduction channel, and a plurality of electrical connection parts electrically connected to the signal processing circuit are provided on the surface of the substrate on the side close to the pressure introduction channel, and the two pressure sensitive elements are electrically connected to the electrical connection parts through leads.
[0012] Preferably, one inner end of the pressure introduction channel is laterally expanded outward along a first direction to form an expanded cavity, and the first pressure sensitive element and the second pressure sensitive element are arranged with a lateral gap and longitudinally face the expanded cavity.
[0013] Preferably, the pressure sensor for the oil tank system further comprises a surrounding frame, which surrounds the pressure sensitive element and is fixed to a corresponding side surface of the substrate, and the surrounding frame is filled with a protective gel covering the pressure sensitive element.
[0014] The present application also claims protection for a fuel tank system, which comprises:
[0015] An oil tank, a control valve, an activated carbon adsorption tank connected to the oil tank via the control valve, and the activated carbon adsorption tank is connected to an external device via the control valve;
[0016] a valve connecting the activated carbon adsorption tank to the environment;
[0017] The above-mentioned pressure sensor for the fuel tank system, wherein the outer end of the pressure introduction channel is directly or indirectly connected to the activated carbon adsorption tank or the fuel tank;
[0018] and a controller, which is used to block the connection between the activated carbon adsorption tank and the environment and external equipment in a first state and connect the activated carbon adsorption tank with the oil tank by controlling the control valve, and to operate the valve in a second state to keep the pressure of the activated carbon adsorption tank within a predetermined pressure range.
[0019] Preferably, the pressure sensor for the oil tank system is mechanically mounted on the control valve and indirectly connected to the oil tank.
[0020] Preferably, the pressure sensor for the oil tank system is mechanically mounted on the oil tank and is directly connected to the oil tank.
[0021] The fuel tank system of the present application can realize leak detection and fuel vapor pressure monitoring respectively in leak detection and normal working state through the above-mentioned pressure sensor for the fuel tank system, thereby reducing system cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a structural schematic diagram of a pressure sensor according to a preferred embodiment;
[0023] Figure 2 It is a structural schematic diagram of a fuel tank system of a preferred embodiment;
[0024] In the figure: 1, fuel tank; 2, activated carbon adsorption tank; 3, fuel distributor; 4, control valve; 500, signal processing circuit; 501a, first pressure through hole; 501b, second pressure through hole; 501, substrate; 502, electrical connector; 503, terminal; 504, frame; 505, protective gel; 50, electronic module assembly; 510, main body; 51, main shell; 520, pressure introduction channel; 52a, expansion cavity; 52, connecting pipe; 53, electrical connection part; 54, upper cover; 55a, vent hole; 55b, waterproof breathable membrane; 55c, ventilation gap; 55, dust cover; 56, first pressure sensitive element; 57, second pressure sensitive element; 58, sealing element; 5a, sensor cavity; 5, pressure sensor; 6, valve; 7, fuel pump; 8, flow valve. DETAILED DESCRIPTION
[0025] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. The following embodiments are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application. In the following description, the same symbols are used to represent the same or equivalent elements, and repeated descriptions are omitted.
[0026] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the products of the present application are usually placed when in use, or the directions or positional relationships usually understood by those skilled in the art, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the equipment or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limitations on the present application. In addition, the prepositive terms "first", "second", "third", etc. are only used to distinguish the modified objects, and cannot be understood as indicating or implying relative importance.
[0027] In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0028] It should be further understood that the term “and / or” used in the specification and corresponding claims of this application refers to any and all possible combinations of one or more of the listed items.
[0029] like Figure 1 As shown. A pressure sensor preferably implemented in the present application includes a shell (not marked) and two pressure-sensitive elements, a first pressure-sensitive element 56 and a second pressure-sensitive element 57, which are arranged inside the shell (i.e., the sensor cavity 5a). The shell may include a main shell 51 with a concave cavity formed at the upper end and an upper cover 54 with a fixed cover arranged on the top of the above-mentioned concave cavity, so that the above-mentioned sensor cavity 5a is surrounded by the main shell 51 and the upper cover 54. The main shell 51 is provided with a pressure introduction channel 520 connected to the inside of the shell to introduce the pressure medium to be measured. The first pressure-sensitive element 56 and the second pressure-sensitive element 57 are both sealedly connected to the two pressure-sensitive elements at one end of the inner side of the pressure introduction channel 520 to independently measure the pressure of the pressure medium to be measured.
[0030] The first pressure sensitive element 56 measures the pressure of the pressure medium to be measured with a first measurement accuracy to obtain a first pressure, and the second pressure sensitive element 57 measures the pressure of the pressure medium to be measured with a second measurement accuracy to obtain a second pressure. The first measurement accuracy is higher than the second measurement accuracy.
[0031] Among them, the pressure sensor 5 may also include an electronic module assembly 50. The electronic module assembly 50 may include a substrate 501 that extends generally laterally and is sealed to the inner end of the pressure introduction channel 520. For example, the bottom of the substrate 501 may be bonded to the periphery of the inner end of the pressure introduction channel 520 by a sealant, or the substrate 501 may be pressed downward and sealed to the periphery of the inner end of the pressure introduction channel 520 by a sealing ring on the lower side. Two pressure through holes, a first pressure through hole 501a and a second pressure through hole 501b, which are connected to the pressure introduction channel 520, may be provided on the substrate 501. The first pressure sensitive element 56 is blocked at the end of the first pressure through hole 501a away from the pressure introduction channel 520. The second pressure sensitive element 57 is blocked at the end of the second pressure through hole 501b away from the pressure introduction channel 520 (i.e. Figure 1 The electronic module assembly 50 may further include a signal processing circuit 500 to process the electrical signals of the first pressure and the second pressure. The signal processing circuit 500 may be disposed on a side surface of the substrate 501 away from the pressure introduction channel 520 (i.e. Figure 1 The signal processing circuit 500 may further include a frame 504. The frame 504 surrounds the pressure sensitive elements and is fixed to the corresponding side surface of the substrate 501. The frame 504 is filled with a protective gel 505 covering the pressure sensitive elements.
[0032] In some other schemes, alternatively, the first pressure sensitive element 56 is blocked at one end of the first pressure through hole 501a close to the pressure introduction channel 520. The second pressure sensitive element 57 is blocked at one end of the second pressure through hole 501b close to the pressure introduction channel 520. At this time, a plurality of electrical connection parts (not shown) electrically connected to the signal processing circuit 500 may be provided on a side surface of the substrate 501 close to the pressure introduction channel 520. For example, the electrical connection part may be electrically connected to the signal processing circuit 500 on the upper surface of the substrate 501 through a metallized via (Via) provided in the substrate 501. The two pressure sensitive elements are electrically connected to the electrical connection part through leads. At this time, the enclosure 504 can be conveniently arranged in the enlarged cavity 52a.
[0033] The housing may include a main housing 51 and an upper cover 54. The main housing 51 may include a main body 510 with a depression formed at the upper end facing downward. The upper cover 54 is provided on the upper end of the depression of the main body 510 to form a sensor cavity 5a. The upper cover 54 may be provided with a vent 55a for connecting the interior of the sensor to the environment so as to introduce the ambient pressure as a reference pressure. A dust cover 55 may be fixed to the outer end of the vent 55a. A ventilation gap 55c is left between the dust cover 55 and the outer part of the upper cover 54. A waterproof breathable membrane 55b may be provided at the outer end of the vent 55a. Additionally or alternatively, a waterproof breathable membrane 55b may also be provided at the inner end of the vent 55a.
[0034] A connecting tube 52 may be formed downward at the lower end of the main body 510, and the inner cavity of the connecting tube 52 constitutes at least a part of the pressure introduction channel 520. A sealing member 58 may be sleeved on the outside of the connecting tube 52. An electrical connecting portion 53 may also be formed on the main body 510, and a plurality of terminals 503 are molded in the electrical connecting portion 53. The inner end of the terminal 503 extends inwardly into the sensor inner cavity 5a, and forms an electrical connection with the signal processing circuit 500 through the electrical connector 502.
[0035] Please refer to Figure 2 . Figure 2 A fuel tank system is shown, which includes a fuel tank 1, a control valve 4, and an activated carbon adsorption tank 2 connected to the fuel tank 1 via the control valve 4. The activated carbon adsorption tank 2 is connected to an external device via the control valve 4. The above-mentioned external device can be a fuel distributor 3 of an engine, and the fuel distributor 3 can obtain fuel from the fuel tank 1 through a fuel pump 7. A flow valve 8 for controlling the amount of fuel vapor delivery can also be provided between the control valve 4 and the fuel distributor 3. The fuel tank system also includes a valve 6, which is used to connect the activated carbon adsorption tank 2 to the environment to keep the pressure of the activated carbon adsorption tank 2 within a predetermined pressure range. For example, when the pressure in the activated carbon adsorption tank 2 is too low, the valve 6 allows the ambient atmosphere to be sucked into the activated carbon adsorption tank 2, and when the pressure in the activated carbon adsorption tank 2 is too high, the gas in the activated carbon adsorption tank 2 is allowed to be at least partially discharged through the valve 6.
[0036] The fuel tank system also includes the above-mentioned pressure sensor 5 and a controller (not shown). The outer end of the pressure introduction channel 520 of the pressure sensor 5 is connected to the activated carbon adsorption tank 2 or the fuel tank 1. In the first state, the controller is used to control the valve 6 to close and the channel leading to the external device to close (for example, close the P4 port), and the activated carbon adsorption tank 2 and the fuel tank 1 are connected through the control valve 4, so as to obtain the pressure in the connecting space between the activated carbon adsorption tank 2 and the fuel tank 1 through the pressure sensor 5; in the second state, the controller controls the valve 6 to work normally, that is, the controller controls the valve 6 to connect the activated carbon adsorption tank 2 to the environment so that the pressure of the activated carbon adsorption tank 2 is maintained in a predetermined pressure range.
[0037] The pressure sensor 5 can be directly installed and connected to the P3 port of the control valve 4. The activated carbon adsorption tank 2 can be connected to the P1 port of the control valve 4, the fuel tank can be connected to the P2 port of the control valve 4, and the flow valve 8 can be connected to the P4 port of the control valve 4. The control valve 4 can be a solenoid valve, which, in the first state (i.e., the leak detection state), disconnects the P1 and P4 ports, closes the valve 6, and connects the P1, P2, and P3 ports to each other; in the second state (normal working state), connects the P1 and P4 ports, and allows the valve 6 to work normally. In the first state, the flow valve 8 can also be directly controlled to be completely closed, instead of disconnecting the P1 and P4 ports to block the delivery of fuel vapor to the fuel distributor 3. The control valve 4 can be mechanically fixed to the activated carbon adsorption tank 2 or the fuel tank 1.
[0038] In some other embodiments, the pressure sensor 5 may also be mechanically installed on the oil tank 1 . In this case, the P3 port on the control valve 4 may be omitted, and the connecting pipe 52 of the pressure sensor 5 directly leads to the inside of the oil tank 1 .
[0039] The scope of the disclosure is defined not by the detailed description but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are construed as being included in the disclosure.
Claims
1. A pressure sensor for a fuel tank system, characterized in that: include: A housing having a pressure introduction passage (520) connected to the interior of the housing; Two pressure-sensitive elements, a first pressure-sensitive element (56) and a second pressure-sensitive element (57), are sealedly connected to one end of the inner side of the pressure-introducing channel (520); The measurement accuracy of the first pressure sensitive element (56) is higher than the measurement accuracy of the second pressure sensitive element (57).
2. The pressure sensor for a fuel tank system according to claim 1, characterized in that: It also includes an electronic module assembly (50), which includes a substrate (501) that extends generally transversely and is sealed to one end of the inner side of the pressure introduction channel (520), and the substrate (501) is provided with two pressure through holes, a first pressure through hole (501a) and a second pressure through hole (501b) that are connected to the pressure introduction channel (520); the first pressure sensitive element (56) is sealed at one end of the first pressure through hole (501a) away from the pressure introduction channel (520), and the second pressure sensitive element (57) is sealed at one end of the second pressure through hole (501b) away from the pressure introduction channel (520).
3. The pressure sensor for a fuel tank system according to claim 2, characterized in that: A signal processing circuit (500) electrically connected to the two pressure sensitive elements through leads is provided on a surface of the substrate (501) on a side away from the pressure introduction channel (520).
4. The pressure sensor for a fuel tank system according to claim 1, characterized in that: It also includes an electronic module assembly (50), which includes a substrate (501) that extends generally transversely and is sealed to one end of the inner side of the pressure introduction channel (520), and the substrate (501) is provided with two pressure through holes, a first pressure through hole (501a) and a second pressure through hole (501b) that are connected to the pressure introduction channel (520); the first pressure sensitive element (56) is sealed at one end of the first pressure through hole (501a) close to the pressure introduction channel (520), and the second pressure sensitive element (57) is sealed at one end of the second pressure through hole (501b) close to the pressure introduction channel (520).
5. The pressure sensor for a fuel tank system according to claim 4, characterized in that: A signal processing circuit (500) is arranged on the surface of the side of the substrate (501) away from the pressure introduction channel (520), and a plurality of electrical connection parts electrically connected to the signal processing circuit (500) are arranged on the surface of the side of the substrate (501) close to the pressure introduction channel (520), and the two pressure sensitive elements are electrically connected to the electrical connection parts through leads.
6. The pressure sensor for a fuel tank system according to any one of claims 2 to 5, characterized in that: One inner end of the pressure introduction channel (520) is laterally expanded outward along a first direction to form an expanded cavity (52a), and the first pressure sensitive element (56) and the second pressure sensitive element (57) are arranged with a lateral gap and longitudinally face the expanded cavity (52a).
7. The pressure sensor for a fuel tank system according to any one of claims 2 to 5, characterized in that: It also includes a surrounding frame (504), which surrounds the pressure sensitive element and is fixed to a corresponding side surface of the substrate (501), and the surrounding frame (504) is filled with a protective gel (505) that covers the pressure sensitive element.
8. A fuel tank system, characterized in that: include: An oil tank (1), a control valve (4), an activated carbon adsorption tank (2) connected to the oil tank (1) via the control valve (4), and the activated carbon adsorption tank (2) connected to an external device via the control valve (4); a valve (6) for connecting the activated carbon adsorption tank (2) to the environment; According to any one of claims 1 to 7, the pressure sensor (5) for a fuel tank system, wherein an outer end of the pressure introduction channel (520) is directly or indirectly connected to the activated carbon adsorption tank (2) or the fuel tank (1); and a controller, which is used to block the connection between the activated carbon adsorption tank (2) and the environment and external equipment in a first state and to connect the activated carbon adsorption tank (2) and the oil tank (1) by controlling the control valve (4), and to operate the valve (6) in a second state so that the pressure of the activated carbon adsorption tank (2) is maintained within a predetermined pressure range.
9. The fuel tank system according to claim 8, characterized in that: The pressure sensor (5) for the oil tank system is mechanically mounted on the control valve (4) and is indirectly connected to the oil tank (1).
10. The fuel tank system according to claim 8, characterized in that: The pressure sensor (5) for the oil tank system is mechanically mounted on the oil tank (1) and is directly connected to the oil tank (1).