High-pressure common rail pressure transmitter with long-rod pressure seat and manufacturing method thereof

Abstract

The present invention provides a high-pressure common rail pressure transmitter with a long-rod pressure seat. The high-pressure common rail pressure transmitter with a long-rod pressure seat includes a base, a welding piece, a pressure seat, a strain gauge, a grounding bracket, a circuit board assembly and a socket assembly. The welding piece is arranged on the rear end face of the base, and the radial width of the welding piece is greater than the radial width of the base along the radial direction of the accommodating cavity. The grounding bracket can not only realize the grounding connection, but its supporting part can also stably support the circuit board assembly, and the socket assembly includes an outer cover and a conductive pin. The above-mentioned high-pressure common rail pressure transmitter with a long-rod pressure seat and its manufacturing method can improve the beneficial effects of the manufactured pressure transmitter, such as a smaller weight, stable measurement results, and more convenient manufacturing.

Description

Technical Field

[0001] The invention relates to the technical field of sensors, in particular to a high-pressure common rail pressure transmitter with a long-rod pressure seat and a manufacturing method thereof. Background Art

[0002] Pressure Transducer is a device or apparatus that can sense pressure signals and convert them into usable output electrical signals according to certain rules. Pressure transmitter is the most commonly used sensor in industrial practice. It is widely used in various industrial automatic control environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, military industry, petrochemical, oil wells, electricity, ships, machine tools, pipelines and many other industries.

[0003] Common rail technology refers to a fuel supply method that completely separates the generation of injection pressure and the injection process from each other in a closed-loop system composed of a high-pressure fuel pump, a pressure transmitter, and an electronic control unit ECU (Electronic Control Unit). The high-pressure fuel pump delivers high-pressure fuel to the common fuel supply pipe, the pressure transmitter accurately controls the oil pressure in the common fuel supply pipe, and the electronic control unit ECU controls the injection amount of the injector according to the high-pressure oil pressure. Therefore, the high-pressure common rail pressure transmitter with a long-rod pressure seat plays a key role in the high-pressure common rail system.

[0004] In traditional high-pressure common rail technology, pressure transmitters play a vital role. The common rail pipe is provided with an installation interface for installing the pressure transmitter. In order to meet the requirements of the pressure transmitter's adaptive installation and sensing position. The pressure seat of the conventional high-pressure common rail pressure transmitter on the market is usually an integrated base. Compared with the long-rod pressure seat, the base is usually a metal solid structure, which will cause the entire pressure transmitter to be heavier. The heavier weight of the pressure transmitter will result in higher production costs. Summary of the invention

[0005] An object of the present invention is to solve the deficiencies in the prior art and to provide a high-pressure common rail pressure transmitter with a long-rod pressure seat which is lighter in weight and lower in cost and a method for manufacturing the same.

[0006] A high-pressure common rail pressure transmitter with a long-rod pressure seat is used to measure the oil pressure in the high-pressure common rail pipe, comprising:

[0007] The base is used for fixed installation on the pressure interface of the common rail pipe, the front end of the base extends into the common rail pipe, and the base is provided with a containing cavity:

[0008] A welding piece, arranged on the rear end surface of the base, wherein the radial width of the welding piece is greater than the radial width of the base in the radial direction of the accommodating cavity;

[0009] A long-rod pressure seat, wherein the pressure seat is provided with a sensing cavity for communicating with the common rail pipe along its axial direction, the pressure seat comprises a main body and an extension portion, the front end of the main body is accommodated in the accommodating cavity and is fixedly connected to the base, the length of the pressure seat is greater than the length of the base, the extension portion is arranged at the rear end of the main body, the extension portion extends out of the accommodating cavity, and is located outside the accommodating cavity;

[0010] A strain gauge, disposed on an end surface of the extension portion, the strain gauge being used to obtain a pressure signal in the sensing cavity;

[0011] A grounding bracket, comprising a supporting portion and a convex edge arranged on the outer periphery of the supporting portion, wherein the supporting portion is formed with a receiving groove, the grounding bracket is arranged on the welding piece, the extending portion is received in the receiving groove, and an avoidance hole is opened at the bottom of the supporting portion, the strain gauge is arranged corresponding to the avoidance hole, and the convex edge is fixedly connected to the welding piece;

[0012] A circuit board assembly is disposed on a side of the support portion away from the welding piece and is electrically connected to the ground bracket, and the strain gauge passes through the avoidance hole and is electrically connected to the circuit board assembly; and

[0013] A socket assembly, the socket assembly includes an outer cover and a conductive pin, the outer cover is fixedly connected to the welding piece to form a closed electrical cavity, the extension part, the strain gauge and the grounding bracket, and the circuit board assembly are accommodated in the electrical cavity, and the conductive pin is electrically connected to the circuit board assembly for transmitting a pressure signal.

[0014] In one embodiment, an end portion of the extension portion is received in the avoidance hole, and a gap exists between the avoidance hole and an outer side wall of the extension portion.

[0015] In one embodiment, the pressure seat is a long rod-type columnar structure; the end surface of the sensing cavity is a metal elastic film.

[0016] In one embodiment, the base is columnar, a step portion is provided on a rear end surface of the base, and the welding piece is fixedly connected to the step portion.

[0017] In one embodiment, an isolation surface is formed on the inner side wall of the rear end of the accommodating cavity, and an isolation gap exists between the isolation surface and the outer side wall of the main body of the pressure seat.

[0018] In one embodiment, the outer cover includes an annular shell and a socket, the socket is arranged at one end of the shell, the conductive pin is arranged on the socket, and the shell is connected to the end surface of the welding piece.

[0019] In one embodiment, the housing and the socket are integrally injection molded.

[0020] In one embodiment, the connection between the housing and the socket is filled with sealant.

[0021] In one embodiment, the support portion of the grounding bracket is provided with a clamping ear toward the circuit board assembly, the circuit board assembly is provided with a clamping hole with a conductive layer, and the clamping ear contacts the clamping hole to achieve electrical connection between the circuit board assembly and the grounding bracket.

[0022] A method for manufacturing a high-pressure common rail pressure transmitter having a long-rod pressure seat comprises the following steps:

[0023] Providing the above-mentioned high-pressure common rail pressure transmitter with a long-rod pressure seat;

[0024] The pressure seat is inserted into the base and fixed by welding;

[0025] Stamping a welding piece, and welding and fixing the welding piece to the rear end surface of the base;

[0026] A grounding bracket is formed by stamping, and the grounding bracket is buckled on the extension of the pressure seat, and the convex edge of the grounding bracket is welded and fixed on the welding piece;

[0027] The circuit board assembly is clamped and fixed on the supporting part of the grounding bracket;

[0028] Install the socket assembly, fix the outer cover of the socket assembly on the welding piece, and electrically connect the socket assembly to the circuit board assembly.

[0029] In one embodiment, the steps are further included:

[0030] The socket assembly includes an outer cover, a conductive pin and a conductive spring, the outer cover includes an annular shell and a socket, and the socket is provided with a slot for assembling an elastic pressing block;

[0031] The conductive pin and the outer cover are integrally injection-molded;

[0032] Injecting sealant at the connection between the socket and the outer cover;

[0033] Placing the elastic pressing block in the card slot;

[0034] One end of the conductive spring is laser welded to the conductive pin.

[0035] In the high-pressure common rail pressure transmitter with a long-rod pressure seat manufactured according to the manufacturing method of the high-pressure common rail pressure transmitter with a long-rod pressure seat, the pressure seat is provided with an extended extension portion so that the extension portion of the pressure seat protrudes out of the outside of the base, thereby reducing the length of the base. Since the base is a metal solid structure, the reduction in the length of the base can reduce the weight of the base, thereby reducing the weight of the pressure transmitter as a whole.

[0036] Lighter pressure transmitters help reduce the total weight of the entire system. During installation and maintenance, lighter pressure transmitters are easier to operate and handle, which reduces the difficulty and complexity of installation, and reduces labor costs and time costs. Furthermore, the lighter high-pressure common rail pressure transmitter with a long-rod pressure seat has less inertia when the system is running, and can respond to pressure changes more quickly and accurately, thereby improving the measurement accuracy and sensitivity of the high-pressure common rail pressure transmitter with a long-rod pressure seat, ensuring the precise control and stable operation of the common rail system. In addition, the lighter high-pressure common rail pressure transmitter with a long-rod pressure seat has relatively less impact on the vibration and impact of the common rail system, which helps to improve its reliability and service life.

[0037] Furthermore, in the above-mentioned high-pressure common rail pressure transmitter with a long-rod pressure seat, the grounding function of the circuit board assembly can be achieved by setting the grounding bracket. The grounding bracket can not only achieve the grounding connection, but its supporting part can also stably support the circuit board assembly. The connecting surface between the convex edge and the welding piece is annular, which can ensure the stable relationship between the grounding bracket and the welding piece, and improve the overall stability of the high-pressure common rail pressure transmitter with a long-rod pressure seat.

[0038] The manufacturing method of the high-pressure common rail pressure transmitter with a long-rod pressure seat is convenient for changing the length relationship between the base and the socket assembly, has a low manufacturing cost, is easy to implement, and is convenient for full-line and full-specification production of high-pressure common rail pressure transmitters with long-rod pressure seats. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a perspective view of a high-pressure common rail pressure transmitter having a long-stem pressure seat according to one embodiment.

[0040] Figure 2 yes Figure 1 An exploded view of a high pressure common rail pressure transmitter with a long stem pressure seat is shown.

[0041] Figure 3 yes Figure 2 Schematic diagram of the disassembly of the base and long rod type pressure seat shown.

[0042] Figure 4 yes Figure 3The assembly diagram of the base and the long rod type pressure seat is shown.

[0043] Figure 5 yes Figure 1 A cross-sectional view of a high-pressure common rail pressure transmitter having a long-stem pressure seat is shown.

[0044] Figure 6 yes Figure 2 Schematic diagram of the assembly of the conductive bracket, base, welding piece and pressure seat shown.

[0045] Figure 7 yes Figure 2 A perspective view of the circuit board assembly from another angle is shown.

[0046] Figure 8 yes Figure 2 The schematic diagram of the disassembled structure of the socket assembly is shown.

[0047] Fig. 9 The present invention is a flow chart of a method for manufacturing a high-pressure common rail pressure transmitter having a long-rod pressure seat according to an embodiment.

[0048] Fig.10 for Fig. 9 A flowchart of the manufacturing method of the socket assembly of the high-pressure common rail pressure transmitter is shown.

[0049] The following are the descriptions of the reference numerals:

[0050] 1. base; 11. accommodating cavity; 12. first step portion; 121. abutting surface; 13. mounting surface; 14. isolation surface;

[0051] 2. Soldering piece;

[0052] 3. pressure seat; 31. induction chamber; 32. main body; 33. extension part; 34. fixing part; 342. second step part; 344. metal elastic film;

[0053] 4. Strain gauge;

[0054] 5. grounding bracket; 51. supporting portion; 512. supporting surface; 514. avoidance hole; 516. clamping ear; 52. convex edge; 53. receiving groove;

[0055] 6. Circuit board assembly; 61. Circuit board; 612. Position limiting boss; 614. Clamp hole; 616. Via hole; 63. Electronic device;

[0056] 7. Socket assembly; 71. Outer cover; 712. Shell; 714. Socket; 715. Card slot; 716. Sealant; 718. Elastic pressing block; 72. Conductive pin; 721. Pin; 73. Conductive spring; 731. Elastic end;

[0057] 8. Electrical cavity. DETAILED DESCRIPTION

[0058] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0059] High-pressure common rail refers to an advanced technology for fuel injection in diesel or gasoline engines. At present, high-pressure common rail technology is widely used in vehicles, aircraft and other transportation vehicles. The common rail system stores high-pressure fuel through a common rail pipe, uses a pressure transmitter to obtain the high-pressure signal in the common rail pipe, and then the electronic control unit accurately controls the injection timing, injection amount and injection pressure of the injector.

[0060] See also Figure 1 and Figure 2 The present application provides a high-pressure common rail pressure transmitter with a long-rod pressure seat, which includes a base 1, a welding piece 2, a pressure seat 3, a strain gauge 4, a grounding bracket 5, a circuit board assembly 6 and a socket assembly 7. The pressure seat is installed in the base 1. The base 1 and the socket assembly 7 are connected to each other to form the main external structure of the pressure transmitter. The mutual connection between the base 1 and the socket assembly 7 forms an electrical cavity 8, and the strain gauge 4, the grounding bracket 5, the circuit board assembly 6, etc. are installed in the electrical cavity 8.

[0061] The base 1 is used to connect with the high-pressure common rail pipe (not shown), and the front end of the base 1 extends into the common rail pipe. A pressure interface (not shown) is provided on the side wall of the high-pressure common rail pipe. The outer periphery of the base 1 can be provided with threads, and the base 1 can be threadedly installed on the pressure interface of the high-pressure common rail pipe by rotation. The base 1 is a metal structure and has a certain rigidity.

[0062] See also Figure 3 Specifically, in this embodiment, the shape of the base 1 is columnar. The diameters of the columnar bases 1 are substantially the same. The base 1 is provided with a receiving cavity 11 along the axial direction. Therefore, the processing and manufacturing process of the columnar base 1 is relatively simple.

[0063] Specifically, the base 1 can be threadedly fastened to the common rail. Therefore, the base 1 is cylindrical. The outer wall of the base 1 is provided with threads. In other embodiments, the base 1 can also be a hexagonal prism, etc., and the base 1 can be fixedly installed at the pressure interface by welding or other fastening methods. The columnar shape of the base 1 is related to the fixing method of the base 1, as long as the base 1 can be stably fixed to the common rail.

[0064] See also Figure 4, the welding piece 2 is arranged on the rear end surface of the base 1. A first step portion 12 is arranged on the rear end surface of the base 1, and the welding piece 2 is fixedly connected to the first step portion 12. The first step portion 12 is formed with an abutting surface 121, and the abutting surface 121 protrudes in the radial direction. The welding piece 2 is abutted on the abutting surface 121, and the abutting surface 121 can be supported on one side of the welding piece 2. The welding piece 2 is welded and fixed on the abutting surface 121. In addition, the welding piece 2 is sleeved on the first step portion 12.

[0065] Furthermore, the height of the first step portion 12 is greater than or equal to the thickness of the soldering piece 2. When the soldering piece 2 is fixedly disposed on the base 1, the surface of the soldering piece 2 and the rear end surface of the base 1 can be approximately flush.

[0066] Please refer again Figure 2 The welding piece 2 can be a one-time stamping structure. The welding piece 2 is fixed on the first step portion 12. In addition, in the radial direction of the accommodating cavity 11, the radial width of the welding piece 2 is greater than the radial width of the base 1, thereby providing sufficient contact area for the connection of the grounding bracket 5 and the socket assembly 7.

[0067] See also Figure 3 , the pressure seat 3 is a long rod type columnar structure. The total length of the long rod type pressure seat 3 is greater than or equal to 1.5 times the diameter of the pressure seat 3. The pressure seat 3 is provided with a sensing chamber 31 along its axial direction. The sensing chamber 31 is connected to the common rail pipe, and the high-pressure fuel enters the pressure seat 3 through the sensing chamber 31. The pressure seat 3 includes a main body 32 and an extension portion 33. The front end of the main body 32 is accommodated in the accommodating chamber 11 and is fixedly connected to the base 1. The front end of the main body 32 is aligned with the front end of the base 1. A mounting surface 13 is provided on the inner side wall of the accommodating chamber 11 near the front end. The front end of the main body 32 and the mounting surface 13 of the accommodating chamber 11 are assembled and connected by a gap or interference fit.

[0068] See also Figure 5 The inner wall of the accommodating cavity 11 is provided with an isolation surface 14 near the rear end. An isolation gap is formed between the rear end of the main body 32 and the isolation surface 14 of the accommodating cavity 11. The isolation gap can effectively block the influence of the stress generated by the base 1 due to the external force on the pressure seat 3, thereby improving the measurement accuracy and long-term stability of the strain gauge 4.

[0069] Moreover, the length of the mounting surface 13 is less than the length of the isolation surface 14. Moreover, the smaller length of the mounting surface 13 can reduce the contact area between the base 1 and the pressure seat 3, and reduce the contact area between the base 1 and the pressure seat 3. When the pressure transmitter is fixed on the high-pressure common rail, due to the effect of the fixing pressure and welding stress, the accuracy and stability of the pressure transmitter in measuring the high-pressure oil pressure are easily affected by the fastening stress. Moreover, during the long-term use of the high-pressure common rail, due to the wear effect of the fixing effect of the pressure transmitter, the fastening stress between the pressure transmitter and the high-pressure common rail will gradually change, and its influence on the pressure transmitter will also change, making the stability of the measurement data of the pressure transmitter weaker.

[0070] The front end of the pressure seat 3 is provided with a fixing portion 34. The fixing portion 34 is used to enhance the connection strength between the base 1 and the pressure seat 3. The fixing portion 34 is provided with a second step portion 342. Correspondingly, the front end of the base 1 is also provided with a connection structure adapted to the second step portion 342. The outer peripheral wall where the second step portion 342 meets the base 1 is sealed by welding. A circumferential surface weld is formed between the second step portion 342 and the base 1, which is simple to process, and the connection between the pressure seat 3 and the base 1 is more firmly and the sealing is better. In addition, the second step portion 342 and the adapting structure of the base 1 abut against each other to achieve positioning and bearing functions.

[0071] The extension portion 33 is disposed at the rear end of the main body 32. The extension portion 33 extends out of the rear end of the base 1, and the extension portion 33 is located outside the accommodating cavity 11. The length of the pressure seat 3 is longer than that of the base 1.

[0072] In traditional pressure transmitters, the length of the base is long, and the diameter of the rear end of the base is large, which makes the overall base larger and heavier. Therefore, the extension part can avoid the base from being too long and reduce the axial length of the base while ensuring that the pressure seat is of sufficient length. The length of the base is small, so that the weight of the base can be small. The small weight of the base can reduce the weight of the entire pressure transmitter, reduce its installation stress, reduce its inertia, maintain the stability of its connection relationship, and thus improve the stability of the pressure transmitter.

[0073] The extension part 33 is provided with a metal elastic film 344 at one end outside the accommodating cavity 11 to seal the sensing cavity. When the high-pressure fuel enters the sensing cavity 31, the pressure is transmitted to the metal elastic film 344, causing the metal elastic film 344 to deform.

[0074] See also Figure 6 The strain gauge 4 is disposed on the outer surface of the metal elastic film 344, and is used to obtain the pressure signal in the sensing cavity 31. The strain gauge 4 is a high-precision sensitive element and can measure the pressure more accurately.

[0075] The grounding bracket 5 comprises a support portion 51 and a flange 52 arranged on the outer periphery of the support portion 51. The grounding bracket 5 is in a hat shape, the support portion 51 is raised, and the flange 52 is arranged around the outer periphery of the support portion 51. The support portion 51 is cylindrical, and the flange 52 is in a circular ring shape.

[0076] The support portion 51 is formed with a receiving groove 53, and the ground bracket 5 is welded to the rear end of the base 1. The extension portion 33 is received in the receiving groove 53. The height of the extension portion 33 is equal to the height of the support portion 51. The outer side surface of the support portion 51 is formed with a supporting surface 512. The supporting surface 512 is used to support the circuit board assembly 6.

[0077] The high-temperature and high-pressure fuel in the fuel supply pipe flows into the sensing cavity 31 and fills the extension portion 33. Due to the heat conduction, the temperature of the extension portion 33 will also increase. The extension portion 33 is exposed outside the base 1, and the extension portion 33 is located in the receiving groove 53. The cavity structure of the receiving groove 53 is large, which can make the heat of the extension portion 33 dissipate more easily, avoid heat accumulation, and reduce the temperature in the receiving groove 53. Similarly, the support portion 51 of the grounding bracket 5 can also get better heat dissipation, avoiding a high temperature of the support portion 51.

[0078] The convex edge 52 is fixedly connected to the welding piece 2. The convex edge 52 abuts against the welding piece 2, and the convex edge 52 is welded to the welding piece 2. In order to enhance the supporting strength of the supporting portion 51, the annular convex edge 52 completely abuts against the welding piece 2.

[0079] The bottom of the support portion 51 is provided with an avoidance hole 514, and the strain gauge 4 is arranged corresponding to the avoidance hole 514. The strain gauge 4 located outside the extension portion 33 can be electrically connected to the circuit board assembly 6 through the avoidance hole 514.

[0080] In addition, the support portion 51 is provided with a snap-fitting ear 516 toward the circuit board assembly 6. The snap-fitting ear 516 is used to achieve electrical connection while being fixedly connected to the circuit board assembly 6. Two snap-fitting ears 516 may be provided. The two snap-fitting ears 516 are symmetrically distributed on both sides of the avoidance hole 514. The snap-fitting force of the snap-fitting ears 516 on the circuit board assembly 6 is symmetrically distributed, which can ensure that the circuit board assembly 6 can be stably fixed on the support portion 51.

[0081] The grounding bracket 5 is a metal stamping part. The mounting ears 516 are integrally formed on two opposite sides of the avoidance hole, which can enhance the structural stability of the grounding bracket 5.

[0082] Furthermore, the end of the extension portion 33 is received in the avoidance hole 514. The shape of the avoidance hole 514 matches the shape of the extension portion 33. There is a gap between the avoidance hole 514 and the outer wall of the extension portion 33. Therefore, there is no interference between the extension portion 33 and the avoidance hole 514, thereby avoiding affecting the accuracy of the measurement of the strain gauge 4.

[0083] See also Figure 7 The circuit board assembly 6 is used to receive the pressure signal obtained by the strain gauge 4 and perform digital processing on the pressure signal. The circuit board assembly 6 includes a circuit board 61 and an electronic device 63.

[0084] The circuit board 61 is disposed on the support portion 51 and is electrically connected to the ground bracket 5. The support portion 51 has good heat dissipation capability, which can ensure that the temperature of the circuit board 61 is not too high, so that the electronic devices 63 on the circuit board 61 can work stably.

[0085] In addition, there is a gap between the circuit board 61 and the support portion 51. The gap can prevent a short circuit between the circuit board 61 and the support portion 51, and facilitates wiring and vias of the circuit board. To ensure stable fixation of the circuit board 61, a limiting boss 612 is provided on the side of the circuit board 61 facing the support portion. The limiting boss 612 is limited and abutted between the circuit board 61 and the support portion 51, so that a gap is maintained between the circuit board 61 and the support portion 51.

[0086] The circuit board 61 is provided with a clamping hole 614. Specifically, the inner wall of the clamping hole 614 is provided with a metal layer, and the clamping ear 516 is interference-fitted with the clamping hole 614 through a clamping action, and the clamping ear 516 is in electrical contact with the conductive layer of the clamping hole 614 to realize the electrical connection between the circuit board 61 and the ground bracket 5.

[0087] The circuit board 61 is provided with a through hole 616 corresponding to the avoidance hole 514. The through hole 616 is provided corresponding to the strain gauge 4 and is used to pass a binding wire binding the strain gauge 4 and the circuit board 61. The strain gauge 4 is electrically connected to the circuit board 61 through the binding wire.

[0088] See also Figure 5 and Figure 8 The socket assembly 7 includes an outer cover 71, a conductive pin 72 and a conductive spring 73. The outer cover 71 is fixedly connected to the rear end surface of the base 1 to form a closed electrical cavity 8. The extension portion 33, the strain gauge 4, the grounding bracket 5, and the circuit board assembly 6 are accommodated in the electrical cavity 8. The conductive pin 72 is electrically connected to the circuit board assembly 6 for transmitting a pressure signal. One end of the conductive pin 72 is electrically connected to the circuit board 61 through the conductive spring 73. The other end of the conductive pin 72 is electrically connected to the electronic control unit ECU (not shown) for transmitting the pressure signal to the electronic control unit ECU.

[0089] The outer cover 71 includes an annular outer shell 712 and a socket 714. The socket 714 is disposed at one end of the outer shell 712. The conductive pin 72 is disposed on the socket. The outer shell 712 is connected to the welding piece 2 by welding. The socket 714 is a plastic part, and the outer shell 712 and the socket 714 are integrally injection molded. The connection between the outer shell 712 and the socket 714 is filled with a sealant 716. It can be understood that the sealant 716 can be a sealant, which is conventionally a silicone.

[0090] A slot 715 is provided on one side of the socket 714 facing the electrical cavity. The slot 715 is used to fix an elastic pressing block 718. The elastic pressing block 718 can be a rubber block. The rubber block can be in a rectangular parallelepiped shape.

[0091] The shell 712 may be a metal stretch-formed part, that is, the shell 712 may be a metal cover. The length of the shell 712 may be adjusted by a stretching process, thereby adjusting the depth of the outer cover 71. The shell 712 may be a hexagonal shell, or may be a pentagonal shell or a tetragonal shell.

[0092] The housing 712 can be fixed on the welding piece 2 by welding. The outer edge of the welding piece 2 is provided with a welding area for welding the housing 712. In addition, there is a certain distance between the weld between the housing 712 and the welding piece 2 and the weld between the grounding bracket 5 and the welding piece 2. This distance can ensure the strength of the welding between the housing 712 and the grounding bracket 5, and avoid mutual influence between the two welds.

[0093] See also Figure 8 The conductive pin 72 is provided with a pin 721. One end of the conductive spring 73 is fixedly connected to the pin 721, and the conductive spring 73 and the pin 721 are electrically connected. The conductive spring 73 and the pin 721 can be fixedly connected by welding, clamping, etc. The other end of the conductive spring 73 is an elastic end 731, which is used to be electrically connected to the circuit board 61.

[0094] When the socket assembly 7 is mounted on the base 1, the elastic end 731 of the conductive spring 73 abuts against the circuit board 61 and is electrically connected to the circuit board 61. The elastic pressing block 718 presses the elastic end 731 of the conductive spring 73 to stably fix the conductive spring 73 on the circuit board 61.

[0095] The elastic deformation of the elastic pressing block 718 is relatively stable. The elastic pressing block 718 can better press and fix the elastic end 731 of the conductive spring sheet 73 on the circuit board 61, ensuring that the conductive spring sheet 73 is evenly stressed and will not move.

[0096] The elastic pressing block 718 not only presses the conductive spring sheet 73, but also presses the circuit board 61, and the circuit board 61 is stably supported on the supporting portion 51 of the grounding bracket 5. Therefore, after the socket assembly 7 is installed and fixed, the elastic pressing block 718, the conductive spring sheet 73, the circuit board 61, and the grounding bracket 5 are all pressed, so that the components in the electrical cavity 8 can be stably fixed. Therefore, the electrical cavity 8 with a relatively stable structure can make the high-pressure common rail pressure transmitter with a long rod pressure seat adaptable to transportation equipment such as automobiles and airplanes, and can resist the effects of vibration and inertia, thereby improving the service life of the high-pressure common rail system.

[0097] In the above-mentioned high-pressure common rail pressure transmitter with a long-rod pressure seat, the pressure seat 3 is provided with an extended extension portion 33 so that the extension portion 33 of the pressure seat 3 protrudes out of the outside of the base 1, thereby reducing the length of the base 1. Since the base 1 is a metal solid structure, the reduction in the length of the base 1 can reduce the weight of the base 1, thereby reducing the weight of the pressure transmitter as a whole. The light weight of the high-pressure common rail pressure transmitter with a long-rod pressure seat has the following main advantages:

[0098] First, the lighter weight helps to reduce the total weight of the entire system. During installation and maintenance, the lighter strain gauge is easier to operate and handle, which reduces the difficulty and complexity of installation and reduces labor and time costs.

[0099] Furthermore, the lighter high-pressure common rail pressure transmitter with a long-rod pressure seat generates less inertia when the system is running, and can respond to pressure changes more quickly and accurately, thereby improving the measurement accuracy and sensitivity of the high-pressure common rail pressure transmitter with a long-rod pressure seat and ensuring precise control and stable operation of the common rail system.

[0100] In addition, the lighter high-pressure common rail pressure transmitter with a long-rod pressure seat has relatively less impact on the vibration and impact of the common rail system, which helps to improve its reliability and service life.

[0101] Furthermore, in the above-mentioned high-pressure common rail pressure transmitter with a long-rod pressure seat, the grounding effect of the circuit board assembly 6 can be achieved by setting the grounding bracket 5. The grounding bracket 5 can not only achieve grounding connection, but its support portion 51 can also stably support the circuit board assembly 6, and the connection surface between its convex edge 52 and the base 1 is annular, which can ensure the stable relationship between the grounding bracket 5 and the base 1, and the supporting effect of the support portion 51 on the circuit board assembly 6 improves the stability of the overall high-pressure common rail pressure transmitter with a long-rod pressure seat.

[0102] In a traditional engine, due to the very limited spatial structure of the engine, when the pressure transmitter is installed on the high-pressure common rail pipe, the space inside the common rail pipe is also limited, and the space outside the common rail pipe is also relatively limited. In order to adapt to the installation of pressure transmitters for engines of different models, the length ratio relationship between the base and the socket assembly needs to be designed specifically so that the pressure transmitter can adapt to the installation requirements of different engines. For the traditional one-piece metal base, metal bases of different lengths need to be processed and designed separately, and the processing process is relatively complicated, and the design cost and processing cost are both high.

[0103] In the high-pressure common rail pressure transmitter with a long-rod pressure seat of this embodiment, since the base 1, the welding piece 2 and the grounding bracket 5 are split-type designs, and the three are stably connected by welding. Since its grounding bracket 5 is welded to the extension 33 of the pressure seat 3, the height of the support portion 51 is equal to the height of the extension portion 33. The depth of the electrical cavity 8 is equal to the height of the shell 712. In addition, the height of the shell 712 is equal to the sum of the height of the support portion 51, the thickness of the circuit board 61 and the thickness of the elastic pressure block 718. Therefore, when adjusting the length ratio of the base 1 and the socket assembly 7 for different high-pressure common rail pressure transmitters with long-rod pressure seats to meet the installation requirements of engines of different models, it is only necessary to design the corresponding length of the base 1 as needed so that the length of the extension 33 meets the installation of the grounding bracket 5. In addition, the columnar structure of the base 1 only needs to cut and process columns of different lengths, so the length of the base 1 provided in this application can be adjusted more conveniently. In addition, the height adjustment of its electrical cavity can be achieved by changing the height of the shell 712.

[0104] Therefore, the high-pressure common rail pressure transmitter with a long-rod pressure seat provided in this embodiment can not only reduce its weight, but also facilitate the manufacture of high-pressure common rail pressure transmitters with long-rod pressure seats of various lengths.

[0105] See also Fig. 9 The present disclosure also provides a method for manufacturing a high-pressure common rail pressure transmitter having a long-rod pressure seat, comprising the following steps:

[0106] Step S10, providing the high-pressure common rail pressure transmitter with the long-rod pressure seat.

[0107] Step S20 , the pressure seat 3 is inserted into the base 1 and fixed by welding, and the extension portion of the pressure seat 3 extends out of the base 1 .

[0108] Step S30 , punching out the welding piece 2 , and welding and fixing the welding piece 2 on the rear end surface of the base 1 .

[0109] Step S40 , stamping and forming the grounding bracket 5 , and buckling the grounding bracket 5 on the extension portion 33 of the pressure seat 3 , and welding and fixing the convex edge of the grounding bracket 5 on the welding piece 2 .

[0110] Step S50 , clamping and fixing the circuit board assembly 6 on the supporting portion of the ground bracket 5 .

[0111] Step S60 , installing the socket assembly 7 , fixing the outer cover of the socket assembly 7 on the welding piece 2 , and electrically connecting the socket assembly 7 to the circuit board assembly 6 .

[0112] In step S20, the processing of the base 1 may include cutting a column steel of a preset length, and processing it by a Swiss-type machine to form an axial accommodation cavity and an external thread. Similarly, the processing of the pressure seat 3 may include cutting a column steel of a preset length, and processing it by a Swiss-type machine to form an axial sensing cavity. The processing process can be automated, and the processing accuracy is high, meeting the quality requirements.

[0113] In contrast, the traditional base is an integrated structure, which is formed by cutting. Since the rear end diameter of the traditional base is relatively large, the processing of the traditional base requires the use of steel with a larger diameter, and a large amount of cutting work is required to form it, which belongs to the steel finishing method, and its production cost and material cost are both high, and the processing difficulty is relatively large.

[0114] The base 1 of the present application has a relatively simple structure, which makes it easier to manufacture and greatly reduces the manufacturing cost.

[0115] Then, the pressure seat 3 is accommodated in the base 1 , and the pressure seat 3 and the front end of the base 1 are welded by laser welding, so as to realize the fixed connection between the pressure seat 3 and the base 1 .

[0116] The front end of the pressure seat 3 is aligned with the front end of the base 1 , and the extension portion 33 of the pressure seat 3 extends out of the rear end of the base 1 .

[0117] When it is necessary to produce bases 1 and pressure seats 3 of different lengths, it is only necessary to cut the steel into corresponding lengths and process them. Compared with fine processing of steel, the production costs of the pressure seat 3 and the base 1 are greatly reduced, and the production is convenient.

[0118] In step S30, the welding piece 2 is a stamped structural part, which is simple to manufacture and easy to operate. In addition, for different types of high-pressure common rail pressure transmitters with long-rod pressure seats, the design and manufacture of the welding piece 2 are relatively easy to adjust.

[0119] Furthermore, the welding piece 2 is fixed on the base 1 by laser welding, and the laser welding operation can be automated, with low welding cost and easy operation.

[0120] In step S40, the grounding bracket 5 is a stamped structural part, which can be stamped in one piece, has a relatively simple structure, and has a mature manufacturing process. Therefore, the operation is relatively simple and easy to implement for manufacturing grounding brackets 5 of different sizes.

[0121] Furthermore, the ground bracket 5 can be welded to the welding piece 2 by laser automatic welding technology, and the welding operation is simple and the manufacturing cost is low. Furthermore, the welding piece is thin, and the welding piece 2 and the ground bracket 5 can improve the overall rigidity and strength after being welded.

[0122] When the length of the socket assembly 7 of the high-pressure common rail pressure transmitter is different, the height of the grounding bracket 5 will also be adjusted according to the height design of the socket assembly 7 to ensure stability. When the height of the grounding bracket 5 needs to be adjusted, it is only necessary to adjust the stamping die accordingly, which is convenient to manufacture and has a low design cost.

[0123] Step S50 , clamping and fixing the circuit board assembly 6 on the supporting portion of the ground bracket 5 .

[0124] The circuit board 61 and the grounding bracket 5 are fixedly connected by the snap-fit ​​ears 516 and the snap-fit ​​holes 614 , so that automatic docking can be achieved, which is easy to operate.

[0125] Step S60 , installing the socket assembly 7 , fixing the outer cover 71 of the socket assembly 7 on the soldering piece 2 , and electrically connecting the socket assembly 7 to the circuit board assembly 6 .

[0126] In one embodiment, the socket assembly 7 needs to be prepared. Fig.10 The preparation process of the socket assembly 7 may mainly include the following steps:

[0127] Step S71 , integrally forming the conductive pins 72 and the outer cover 71 by injection molding.

[0128] The conductive pin 72 and the outer cover 71 are integrally injection molded, which is convenient to manufacture and greatly reduces the manufacturing cost.

[0129] Step S72, pouring sealant 716 at the connection between the socket 714 and the outer cover 71. Pour sealant 716 at the connection between the socket 714 and the outer shell 712. The sealant 716 can maintain good sealing between the socket 714 and the outer shell 712.

[0130] Step S73 , placing the elastic pressing block 718 in the card slot 715 .

[0131] In step S74 , one end of the conductive spring 73 is laser welded to the conductive pin 72 .

[0132] For the socket assembly 7, the outer cover 71 of the socket assembly 7 includes a shell 712. The shell 712 can be formed by a stretching process, that is, the shell 712 can be a metal cover. When the height of the metal cover needs to be adjusted, the metal cover of the corresponding height is stretched according to its design requirements. The stretching process is relatively simple to operate and the cost is also low.

[0133] Therefore, the manufacturing method of the high-pressure common rail pressure transmitter with a long-rod pressure seat is convenient for changing the length relationship between the base 1 and the socket assembly 7, has a low manufacturing cost, is easy to implement, and is convenient for full-line and full-specification production of high-pressure common rail pressure transmitters with long-rod pressure seats.

[0134] Although the welding process is added in the manufacturing method of the high-pressure common rail pressure transmitter, compared with the large amount of steel finishing in the traditional high-pressure common rail pressure transmitter, the manufacturing cost of the high-pressure common rail pressure transmitter of this embodiment is greatly reduced, and its manufacturing difficulty and manufacturing efficiency are also greatly improved.

[0135] The above embodiments are merely exemplary descriptions of the structures. The structures in the embodiments are not fixed combination structures. In the absence of structural conflicts, the structures in multiple embodiments can be used in any combination.

[0136] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A high-pressure common rail pressure transmitter with a long-rod pressure seat, characterized in that: Used to measure the oil pressure in the high pressure common rail pipe, including: A base, used for fixedly mounting on the pressure interface of the common rail pipe, the front end of the base extends into the common rail pipe, and the base is provided with an accommodating cavity; A welding piece, arranged on the rear end surface of the base, wherein the radial width of the welding piece is greater than the radial width of the base in the radial direction of the accommodating cavity; A long-rod pressure seat, wherein the pressure seat is provided with a sensing cavity for communicating with the common rail pipe along its axial direction, the pressure seat comprises a main body and an extension portion, the front end of the main body is accommodated in the accommodating cavity and is fixedly connected to the base, the length of the pressure seat is greater than the length of the base, the extension portion is arranged at the rear end of the main body, the extension portion extends out of the accommodating cavity, and is located outside the accommodating cavity; A strain gauge, disposed on an end surface of the extension portion, the strain gauge being used to obtain a pressure signal in the sensing cavity; A grounding bracket, comprising a supporting portion and a convex edge arranged on the outer periphery of the supporting portion, wherein the supporting portion is formed with a receiving groove, the grounding bracket is arranged on the welding piece, the extending portion is received in the receiving groove, and an avoidance hole is opened at the bottom of the supporting portion, the strain gauge is arranged corresponding to the avoidance hole, and the convex edge is fixedly connected to the welding piece; A circuit board assembly is disposed on a side of the support portion away from the welding piece and is electrically connected to the ground bracket, and the strain gauge passes through the avoidance hole and is electrically connected to the circuit board assembly; and A socket assembly, the socket assembly comprising an outer cover and a conductive pin, the outer cover is fixedly connected to the welding piece to form a closed electrical cavity, the extension portion, the strain gauge, the grounding bracket, and the circuit board assembly are accommodated in the electrical cavity, and the conductive pin is electrically connected to the circuit board assembly for transmitting a pressure signal; The end of the extension portion is received in the avoidance hole, and there is a gap between the avoidance hole and the outer side wall of the extension portion; The base is columnar, and a step portion is provided on the rear end surface of the base, and the welding piece is fixedly connected to the step portion; An isolation surface is formed on the inner side wall of the rear end of the accommodating cavity, and an isolation gap exists between the isolation surface and the outer side wall of the main body of the pressure seat.

2. The high-pressure common rail pressure transmitter with a long-rod pressure seat according to claim 1, characterized in that: The pressure seat is a long rod columnar structure; the end surface of the induction cavity is a metal elastic film.

3. The high-pressure common rail pressure transmitter with a long-rod pressure seat according to claim 1, characterized in that: The outer cover comprises an annular shell and a socket, wherein the socket is arranged at one end of the shell, the conductive pin is arranged on the socket, and the shell is connected to the end surface of the welding piece.

4. The high-pressure common rail pressure transmitter with a long-rod pressure seat according to claim 3, characterized in that: The shell and the socket are integrally injection molded.

5. The high-pressure common rail pressure transmitter with a long-rod pressure seat according to claim 3, characterized in that: The connection between the shell and the socket is filled with sealant.

6. The high-pressure common rail pressure transmitter with a long-rod pressure seat according to claim 1, characterized in that: The supporting portion of the grounding bracket is provided with a clamping ear toward the circuit board assembly, the circuit board assembly is provided with a clamping hole with a conductive layer, and the clamping ear contacts the clamping hole to realize electrical connection between the circuit board assembly and the grounding bracket.

7. A method for manufacturing a high-pressure common rail pressure transmitter having a long-rod pressure seat, comprising the following steps: Provide a high-pressure common rail pressure transmitter with a long-rod pressure seat as described in any one of claims 1 to 6; The pressure seat is inserted into the base and fixed by welding; Stamping a welding piece, and welding and fixing the welding piece to the rear end surface of the base; A grounding bracket is formed by stamping, and the grounding bracket is buckled on the extension of the pressure seat, and the convex edge of the grounding bracket is welded and fixed on the welding piece; The circuit board assembly is clamped and fixed on the supporting portion of the grounding bracket; Install the socket assembly, fix the outer cover of the socket assembly on the welding piece, and electrically connect the socket assembly to the circuit board assembly.

8. According to the manufacturing method of the high-pressure common rail pressure transmitter with a long-rod pressure seat according to claim 7, the socket assembly includes an outer cover, a conductive pin and a conductive spring, the outer cover includes an annular shell and a socket, and the socket is provided with a slot for assembling an elastic pressure block; characterized in that, Also includes the steps: The conductive pin and the outer cover are integrally injection-molded; Injecting sealant at the connection between the socket and the outer cover; Placing the elastic pressing block in the card slot; One end of the conductive spring is laser welded to the conductive pin.

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