WO2021143851A1

WO2021143851A1 - Vgt assembly limiting structure and vgt assembly of variable geometry turbocharger

Info

Publication number: WO2021143851A1
Application number: PCT/CN2021/072175
Authority: WO
Inventors: 潘红军; 王澎; 伍培明; 张泽裕; 郑建设
Original assignee: 长城汽车股份有限公司
Priority date: 2020-01-16
Filing date: 2021-01-15
Publication date: 2021-07-22
Also published as: CN112502790B; CN112502790A

Abstract

Disclosed is a VGT assembly limiting structure. The VGT assembly limiting structure comprises a mounting hole (101) which is provided in a mounting disc (1) and penetrates the mounting disc, and a roller (9) fixedly connected into the mounting hole, wherein the roller is pressed in the mounting hole by means of a press-in end (903) of the roller in an interference manner and is provided with a head (901) partially arranged on one side of a shifting disc (2) in a blocking manner, the mounting hole is a stepped hole with the inner diameter increasing in the press-fitting direction of the roller, an annular air cavity (Q) is formed between the press-in end of the roller and the inner wall of the mounting hole due to the increase of the inner diameter of the mounting hole, one end of the air cavity is open, and the other end of the air cavity is closed due to interference press fitting of the roller. According to the limiting structure, an annular air cavity is formed between the press-in end of the roller and the inner wall of the mounting hole, such that the risk of the roller in a VGT assembly being loosened due to heating is reduced. Further disclosed is a VGT assembly of a variable geometry turbocharger.

Description

VGT component limit structure and variable section turbocharger VGT component

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 202010057021.2, titled "VGT component limit structure and variable cross-section turbocharger VGT component" on January 16, 2020, and its entire content Incorporated in this application by reference.

Technical field

The present disclosure relates to the technical field of engine turbocharging, and in particular to a limiting structure for a VGT assembly of a variable-section turbocharger. At the same time, the present disclosure also relates to a variable-section turbocharger using the limiting structure.器VGT component.

Background technique

With the development of technology, people have more and more demanding requirements for the performance of automobile engines, which not only require strong power, but also higher efficiency and clean emissions. People's requirements for engine performance require that the engine can achieve a more efficient working state under various working conditions. In order to have an efficient working state under various working conditions, it must meet the engine's progress under various working conditions. Gas requirements.

In order to meet the intake requirements of the engine, people hope to make the engine intake "variable" through related designs to meet the intake needs under different working conditions, such as the well-known variable valve timing/lift technology, Variable intake manifold technology is developed based on this, and the VGT variable-section turbocharging technology, which is more common on diesel engines, also belongs to this type of design.

VGT (Variable Geometry Turbocharger) variable section turbocharging technology can solve the turbo lag of the turbocharger, allowing the turbocharged engine to ensure a good supercharging effect at high and low speeds. It has been widely used in the field of diesel engines. Applications. Since the exhaust temperature of gasoline engines can reach about 1000°C, which is much higher than the exhaust temperature of diesel engines about 600°C, the current hardware materials used in VGT cannot withstand such a high temperature environment, so this technology has not been able to It is used in gasoline engines.

In recent years, it has been reported that BorgWarner and Porsche have jointly developed a gasoline engine equipped with a variable-section turbocharger through the use of high-temperature aerospace materials. Porsche also refers to this technology as VTG (Variable Turbine Geometry). Variable turbine blade technology, but its essence is still VGT variable section turbocharging technology.

With the emergence of the above-mentioned VTG variable turbine blade technology, various car companies have also begun to develop their own VGT variable section turbochargers, and gradually have models using VGT variable section turbochargers come out. In the existing disclosed VGT variable section turbocharger, the VGT component inside, that is, the component structure for adjusting the exhaust gas intake section of the turbocharger, the roller used for the limit installation of the dial When assembling, special roller guide tooling is required, which is inconvenient to operate, and the existing roller mounting method not only has the risk of the roller being easily loosened by heat, but also makes the thickness of the mounting plate larger, which will bring material Waste.

Overview

In view of this, the present disclosure aims to propose a VGT assembly limiting structure to reduce the risk of heat loosening of the rollers in the VGT assembly.

In order to achieve the above objective, the technical solution of the present disclosure is achieved as follows:

A VGT assembly limit structure is used in a VGT assembly of a variable-section turbocharger. The limit structure constitutes an axial limit for the rotation of the dial plate on the mounting plate of the VGT assembly. The position structure includes a mounting hole on the mounting plate arranged through the mounting plate, and a roller fixedly connected to the mounting hole, and the roller is press-fitted to the mounting hole through its own press-in end. Inside, the roller has a head part partially blocked on one side of the dial, and the mounting hole is a stepped hole whose inner diameter increases along the press-fitting direction of the roller. An annular air cavity is formed between the pressing end of the roller and the inner wall of the mounting hole, one end of the air cavity is open, and the other end is closed due to the interference pressing of the roller.

Compared with the prior art, the present disclosure has the following advantages:

The VGT component limiting structure of the present disclosure forms an annular air cavity between the pressing end of the roller and the inner wall of the mounting hole, and one end of the air cavity is open, and the other end is closed based on the interference pressing of the roller. As a result, the gas cannot flow at the mounting hole, so that the conduction of the heat at the blade to the mounting hole and the interference section of the press-in end can be alleviated, thereby reducing the risk of the roller being loosened due to heat.

At the same time, in the present disclosure, the outer diameter of the end part of the press-in end is small, which can facilitate the press-in of the press-in end of the roller into the mounting hole. The setting of the interference fit length between the press-in end and the mounting hole can ensure the press-fitting The stability can also ensure the stability of the mounting plate structure, and the arrangement of the protrusions, the mounting ring and the outer protrusions, etc., can facilitate the arrangement of the components and facilitate the overall assembly and molding of the VGT assembly.

Another object of the present disclosure is to provide a variable-section turbocharger VGT assembly for use in a variable-section turbocharger, and:

The VGT assembly includes a mounting plate and a rear cover arranged oppositely, a dial plate arranged on the mounting plate rotating, a distance sleeve fixedly connected to the mounting plate and/or the rear cover, and a distance sleeve arranged on the mounting plate and/or the rear cover. The VGT assembly limit structure as described above on the mounting plate, and the distance sleeve is supported between the mounting plate and the back cover, and the distance sleeve and the limit structure are all along the A plurality of the dials arranged at intervals in the circumferential direction;

The VGT assembly also includes a shift fork that can receive an external rotational driving force to drive the dial to rotate, and a plurality of blade units arranged at intervals along the circumference of the dial, and the blade unit has a The blade between the mounting plate and the back cover, and the shift lever that constitutes the transmission connection between the blade and the dial plate.

The variable-section turbocharger VGT assembly of the present disclosure adopts the above-mentioned limiting structure, which can alleviate the conduction of heat at the blade to the installation hole and the interference section of the press-in end, and can reduce the risk of the rollers in the assembly being heated and loosened .

In addition, the VGT assembly of the present disclosure connects the shaft body on the blade and the arrangement of the shift lever shaft body with the connecting hole on the shift lever. Since the connecting shaft body is connected in the connecting hole, the shift lever shaft body can be brought into contact with the mounting plate. , And the small size of the connecting shaft body. On the one hand, through the contact between the shift lever shaft body and the mounting plate, it is possible to take advantage of the fact that the shift lever part does not need to use high hardness materials, so that the shift lever shaft body and the mounting plate have similar hardness to reduce installation The wear of the disc and the small size of the connecting shaft can also reduce the overall material of the blade to reduce its cost.

In addition, the VGT assembly of the present disclosure, through the abutment between the spacer and the rear cover, and the arrangement of the elastic part between the rear cover and the housing, when the exhaust gas contains large particles, if the large particles received by the rear cover are formed When the squeezing force exceeds the elastic force of the elastic part, the back cover will compress the elastic part and separate from the end surface of the spacer. This can increase the distance between the blade and the back cover, and between the mounting plate and the back cover. The particles are discharged under the action of, which can reduce the chance of jamming of the blades of the VGT assembly.

The above description is only an overview of the technical solutions of the present disclosure. In order to understand the technical means of the present disclosure more clearly, they can be implemented in accordance with the content of the specification, and in order to make the above and other objectives, features and advantages of the present disclosure more obvious and easy to understand. In the following, specific embodiments of the present disclosure are specifically cited.

Brief description of the drawings

The drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The exemplary embodiments and descriptions of the present disclosure are used to explain the present disclosure, and do not constitute an improper limitation of the present disclosure. In the attached picture:

FIG. 1 is a partial schematic diagram of a VGT assembly according to an embodiment of the disclosure;

Figure 2 is a cross-sectional view in the direction of A-A in Figure 1;

3 is another partial schematic diagram of the VGT assembly according to an embodiment of the disclosure;

Figure 4 is a cross-sectional view in the direction of B-B in Figure 3;

FIG. 5 is a schematic diagram of the structure of the shift lever according to the embodiment of the disclosure;

Figure 6 is a schematic structural diagram of the shift lever (with a material reducing groove) according to an embodiment of the disclosure;

Figure 7 is a front view of the shift lever shown in Figure 5;

FIG. 8 is a schematic diagram of the structure of the blade according to an embodiment of the disclosure (using a blade shaft);

FIG. 9 is a schematic diagram of the structure of the shift lever (with a material reducing hole) according to an embodiment of the disclosure;

Fig. 10 is a schematic structural diagram of the shift lever shown in Fig. 9 at another angle;

Figure 11 is a schematic structural diagram of the blade according to an embodiment of the disclosure (using a connecting shaft);

Figure 12 is a partial enlarged view of part C in Figure 11;

Figure 13 is a schematic structural diagram of a shift lever adapted to the blade shown in Figure 11 (using a shift fork shaft);

Fig. 14 is a partial schematic diagram of the VGT assembly when the blade of Fig. 11 and the lever of Fig. 12 are used;

Fig. 15 is a cross-sectional view in the direction of D-D in Fig. 13;

16 is a schematic diagram of the structure of the adjusting pin according to the embodiment of the disclosure;

FIG. 17 is a schematic structural diagram of a shift fork according to an embodiment of the disclosure;

18 is a schematic diagram of the arrangement of the roller according to the embodiment of the disclosure;

19 is a schematic diagram of the structure of the mounting hole on the mounting plate according to the embodiment of the disclosure;

20 is a schematic diagram of the structure of the roller according to an embodiment of the disclosure;

21 is a schematic diagram of the arrangement of the VGT assembly in the supercharger according to the embodiment of the disclosure;

Fig. 22 is a partial enlarged view of part E in Fig. 21.

A detailed description

It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other if there is no conflict.

Hereinafter, the present disclosure will be described in detail with reference to the drawings and in conjunction with the embodiments.

This embodiment relates to a limiting structure in a VGT assembly of a variable-section turbocharger, and this embodiment also further relates to a VGT assembly of a variable-section turbocharger with the limiting structure of the VGT assembly. At this time, in order to facilitate the description of the structure of the limiting structure of this embodiment, and its arrangement in the VGT assembly and even the variable-section turbocharger, the overall VGT assembly structure and the components in the following introduction will be described. In the process of the arrangement of the supercharger, the limiting structure of this embodiment will be described in detail.

Before describing the overall VGT assembly structure and its arrangement in the supercharger, it needs to be stated that for the limit structure of this embodiment, it is undeniable that in addition to being applied to the VGT assembly described below, Of course, the limiting structure can also be used for variable-section turbocharger VGT components with other structural forms. This embodiment does not limit this, as long as the limiting structure of this embodiment can be provided in the VGT component, and It can also obtain the expected use effect.

In this embodiment, with regard to the variable area turbocharger with VGT components, the turbocharger can be like other turbochargers of the same type currently used. When the engine is running at low speed, the blades are adjusted so that the blades are composed of The cross-sectional area of the nozzle ring decreases, the turbine speed rises, and the boost pressure increases to ensure the boost pressure and intake air volume at low speeds. When the engine is running at high speed, the blades are adjusted to increase the nozzle ring cross-sectional area and the turbine speed decreases to prevent the increase. When the engine is accelerating, the blades can be adjusted to reduce the nozzle ring cross-sectional area and increase the speed of the supercharger to increase the boost pressure and intake air volume, increase the response speed of the supercharger, and meet the requirements of transient operation. Gas requirements.

The variable cross-section turbocharger of this embodiment includes a casing, a turbine 13 arranged in the casing to rotate, and a VGT assembly arranged in the casing. The VGT assembly is used to counter the flow direction. The flow cross section of the exhaust gas of the turbine 13, that is, the cross-sectional area of the nozzle ring described above is adjusted, thereby realizing a so-called supercharger cross-section variable.

Since the main invention of the supercharger of this embodiment lies in the VGT assembly and the corresponding arrangement of the VGT assembly in the supercharger, this article will only describe the VGT assembly and its arrangement in the supercharger. Except for the VGT components and their arrangement related content described below, for other structures in the variable-section turbocharger, refer directly to the existing disclosed variable-section turbochargers of the same kind as this embodiment. That's it, it will not be repeated here.

In this embodiment, the VGT assembly arranged in the casing of the supercharger, as shown in FIG. 1 to FIG. 4, has an overall structure including a mounting plate 1, a dial plate 2, a shift lever 3, an adjustment pin 4, and a shift fork. 5. Distance sleeve 6, rocker shaft 7, blade 8, roller 9 and rear cover 10.

Among them, the mounting plate 1 and the rear cover 10 constitute the structural basis of the VGT assembly, the dial 2 is rotatably arranged on the mounting plate 1, and the dial 2 and the rear cover 10 are respectively located on opposite sides of the mounting plate 1, and the dial 3 It forms a blade unit with the blade 8 that can accept the rotation of the dial 2 to finally realize a blade unit with a variable cross-section. The adjustment pin 4, the shift fork 5 and the rocker shaft 7 form an external rotational driving force that drives the The shift fork transmission unit that the dial 2 rotates.

The distance sleeve 6 is arranged on the mounting plate 1 and/or the back cover 10 and abuts between the installation plate 1 and the back cover 10. In this embodiment, as an exemplary structure, the distance sleeve 6 is specifically One end is fixedly connected to the mounting plate 1 and the other end abuts against the rear cover 10 to define a space between the mounting plate 1 and the rear cover 10 for the arrangement of the blades 8. The roller 9 is fixedly connected to the mounting plate 1 and is used for the axial limit of the dial 2 after the mounting plate 1 is installed.

In this embodiment, the above blade unit, spacer 6 and roller 9 are all arranged in multiple groups or at intervals along the circumferential direction of the mounting plate 1 or the dial 2. As for the specific arrangement number of each component, you can In actual implementation, the selection is made according to the overall design requirements of the supercharger, as long as its setting is consistent with the structure and arrangement principles described in this article. In addition, for the external rotational driving force delivered to the shift fork 5 via the rocker shaft 7, the rotational driving force is generally provided by an actuator fixed to the engine corresponding to the supercharger. Stepper motor with higher rotation control accuracy.

In this embodiment, based on the control signal of the engine controller, the actuator outputs rotational driving force, the shift fork transmission unit receives the external rotational driving force to make the dial 2 rotate, and the rotation of the dial 2 is transmitted through the shift lever 3. Finally, the blades 8 are driven to rotate, so that by adjusting the rotation angle of each blade 8, the cross-sectional area of the nozzle ring can be changed, thereby adjusting the working performance of the turbocharger.

The relevant parts of the VGT assembly will be described in detail below in conjunction with the drawings, and it should be noted that for the components in this embodiment, the following description is a preferred implementation form in terms of structure and specific arrangement, except The structure and arrangement form given below, of course, can also be used in other ways that can achieve the same function and effect. Other ways here can be, for example, a conventional alternative structure of a certain component, or a conventional alternative in its arrangement. This embodiment does not impose restrictions on these.

In addition, it should first be explained that the rotation arrangement of the dial 2 on the mounting plate 1 and the arrangement of the mounting plate 1 and the rear cover 10 in the turbocharger housing will be described later in conjunction with the corresponding drawings. Introduce it. Therefore, the blade unit including the shift lever 3 and the blade 8 and the shift fork transmission unit including the adjusting pin 4 and the shift fork 5 will be described in advance.

In this embodiment, the shift lever 3 in the above-mentioned blade unit is specifically used to receive the rotation drive of the dial 2 in the VGT assembly to drive the corresponding blade 8 to rotate, as shown in FIG. 5, the specific structure is , The shift lever 3 of this embodiment includes a bar-shaped shift lever main body 300, one end of the shift lever main body 300 is provided with a connecting portion connecting it with the blade 8, and relative to the connecting portion, the lever body 300 The other end of the main body 300 is also configured with a protrusion 301. The protrusion 301 is convex toward the side of the lever main body 300 along the thickness direction of the lever main body 300, and in specific implementation, the protrusion 301 is inserted into the corresponding notch formed by the edge of the dial 2, thereby forming The transmission link between the shift lever 3 and the shift plate 2 is capable of receiving the rotation drive of the shift plate 2.

In this embodiment, as a preferred embodiment, from the perspective of reducing weight and facilitating weight reduction, relative to the protrusion 301, a recessed or penetrating lever 3 is also configured on the other side of the lever body 300. Subtracting department set up. At this time, as shown in FIG. 6, the above-mentioned material reduction portion may be, for example, a material reduction groove 303 that is recessed and provided on the lever body 300. Regarding the shift lever 3 of this embodiment, it should also be noted that, also as a preferred embodiment, one end of the shift lever body 300 can be configured to also extend toward the shift lever body 300 along the thickness direction of the shift lever body 300. A convex boss 3011 protruding from the side, and the above-mentioned boss 301 is also located on the boss 3011.

As shown in FIG. 5, it should be noted that when the above boss 3011 is set, along the length direction of the lever body 300, the extension length of the boss 3011 toward the other end of the lever body 300 should be greater than the protrusion 301. Therefore, by using the part of the boss 3011 that exceeds the protrusion 3011, after the lever 3 and the blade 8 are assembled, the contact between this part and the dial 2 can also achieve the same axial direction of the dial 2 The movement limit can further ensure the stability of the setting of the dial 2 on the mounting plate 1.

In addition, for the boss 3011, as an optimized design, in this embodiment, with respect to the boss 3011 on one side of the end of the shift lever 3, the other side of the boss 3011 is configured to have an end surface with the lever body 300. Contiguous curved surface 3012. Through the arrangement of the curved surface 3012, when the boss 3011 and the dial 2 are in contact, the wear between the two can be reduced.

In this embodiment, the end of the shift lever 3 with one end of the boss 3011 and the protrusion 301 is also specifically set as an end plane 305 formed by the lever body 300, the boss 3011, and the boss 301, so that the shift The end of the rod 3 is flat. At the same time, further, in this embodiment, relative to the side with the protrusion 301 and the shift lever shaft 307, the other side end surface of the shift lever 3 can also be set to be flat, so that the shift lever body 300 has a top plane 304. Through the top plane 304 and the end plane 305 that are both flat, the overall structure of the shift lever 3 can be made more concise to facilitate its shaping, and compared with the shift lever structure used in the current variable section turbocharger The plane design of this embodiment can also reduce the size of the shift lever 3, reduce its space occupation, and achieve a certain effect of reducing material and weight. At the same time, since the shift lever 3 is flat and straight as a whole, the shaft structure connected with the blade 8 can also be made shorter, so that the cost can be reduced.

Based on the above-mentioned notch provided on the edge of the dial 2 to cooperate with the protrusion 301 to realize the driving of the dial 2 to the dial 3, the protrusion 301 can also be connected to the dial through its two opposite sides. The inner wall of the notch abuts to form a driving connection between the lever 3 and the dial 2. As a preferred implementation form in this embodiment, as shown in FIG. 7, the two opposite sides of the protrusion 301 are both set in a convex arc shape, and thus arc surfaces located on both sides of the protrusion 301 are formed. 3013.

The arrangement of the curved surface 3013 not only enables better contact between the protrusion 301 and the dial 2, of course, it can also achieve a certain material and weight reduction effect while ensuring the structural strength of the protrusion 301.

Compared with the protrusion 301, the present embodiment is directed to the connecting portion located at the other end of the shift lever 3. At this time, as an exemplary structural form, the connecting portion may be, for example, a through hole 302 opened on the shift lever 3. When the through hole 302 is used, the structure of the blade 8 matched with it is as shown in FIG. 8. A blade shaft 801 is fixedly connected to the blade 8, and the blade shaft 801 passes through the mounting plate 1 and is fixed to the shift lever 3. In the upper through hole 302, and the blade shaft 801 can generally be integrally formed with the blade 8, for example, metal powder injection molding can be used, and conventional methods such as interference insertion or welding can be used between the blade shaft 801 and the through hole 302, for example.

In this embodiment, except that the blade 8 and the blade shaft 801 can be obtained by a metal powder injection molding process, of course, the blade 8 and the blade shaft 801 can also be prefabricated separately and then the two can be fixedly connected together. However, in general, it is preferable to adopt metal powder injection integral molding. At this time, for other exemplary structural forms of the shift lever 3 and the blade 8, as well as the adjustment pin 4, the shift fork 5, etc., which will be mentioned later, they can also preferably be manufactured by a metal powder injection molding process. Of course, in addition to the metal powder injection molding process, each component in this embodiment can also be obtained by other existing processes, as long as the process can ensure the structural performance of the component and meet its use in the variable cross-section supercharger. .

Still referring to FIG. 6, as an example of a preferred arrangement of the material reducing groove 303 of this embodiment, at this time, in comparison with the boss 3011 on the other side of the shift lever 3, the material reducing groove 303 is along the length of the shift lever 3. The extension length of the direction can be greater than that of the boss 3011, so that while ensuring the structural strength of the shift lever 3, it is more conducive to the weight reduction of the shift lever 3. As shown in FIGS. 9 and 10, in addition to the material reduction groove 303, the material reduction part of this embodiment can also use the material reduction hole 306. At this time, the material reduction hole 306 penetrates the boss 3011 and the protrusion. 301 is arranged, and therefore, the protrusion 301 appears as a two-half structure arranged oppositely.

In addition, for the blade unit in the VGT assembly in this embodiment, it should be noted that in addition to the above-mentioned structure, the shift lever 3 and the blade 8 are fixedly connected with the blade shaft 801 as the blade in this embodiment. Another exemplary implementation form of the unit, as shown in FIGS. 11 to 13, at this time, the connecting portion on the shift lever 3 can be a shift lever shaft 307 integrally formed on the shift lever body 300, and accordingly correspond to The blade 8 has a blade body 801 and a connecting shaft 802 fixedly connected to the blade body 801. The lever shaft 307 has a connecting hole 303, and is partially or completely fixed to the connecting hole 303 through the connecting shaft 802. Inside, thereby forming the connection between the blade 8 and the lever 3.

Specifically, the preferred connecting shaft 802 can be interference press fitted in the connecting hole 303, and to ensure the reliability of the press-fit connection, a radially convex bulge can also be constructed on the outer peripheral surface of the connecting shaft 802部803. Each protruding portion 803 is distributed in a plurality of intervals along the circumferential direction of the connecting shaft 802, and each protruding portion 803 is also preferably arranged along the axial direction of the connecting shaft 802, so that the improvement of the connection effect can be better achieved. Purpose.

The cross section of the protruding portion 803 in this embodiment can be, for example, the semicircle shown in FIG. 12, but in addition to the semicircle, of course, the cross section of the protruding portion 803 can also be other shapes such as square, triangle, or semi-ellipse, and In addition to the elongated shape extending in the axial direction of the connecting shaft 802, of course, the protruding portion 803 of this embodiment can also adopt a plurality of convex hemispherical shapes, or a plurality of elongated strips extending in the axial or circumferential direction of the connecting shaft 802. This embodiment does not limit this structure, as long as it can improve the reliability of the interference press fitting of the connecting shaft 802 in the connecting hole 303.

Since the connecting shaft 802 on the blade 8 is pressed into the shift lever shaft 307, after the blade 8 is assembled with the shift lever 3, the shift lever shaft 307 penetrates the mounting plate 1 and contacts the mounting plate 1. For the purpose of reducing the wear between the shift lever shaft 307 and the mounting plate 1, in this embodiment, it is preferable to construct a circumferentially arranged groove on the shift lever shaft 307 on the outer peripheral surface of the shift lever shaft 307. During specific implementation, the number of the grooves, as well as the depth and width thereof, can be selected based on the design experience on the basis of meeting the structural strength of the shift lever shaft 307. Moreover, similar to the groove arrangement on the shift lever shaft 307, for the blade shaft 801 mentioned above, based on the same consideration, of course, a groove structure can also be provided on the outer peripheral surface of the blade shaft 801.

In this embodiment, when the blade shaft 801 is used, the structure of the VGT assembly can be as shown in Figures 1 and 2, and when the matching structure of connecting the shaft body 802 and the shift lever shaft body 307 is adopted, the structure of the VGT assembly can be as follows Shown in Figure 14 and Figure 15. Regardless of whether the blade shaft 801 or the matching structure of the connecting shaft body 802 and the shift lever shaft body 307 is adopted, the reliable arrangement of the blade 8 can be ensured, and it can be well driven by the dial 2.

In addition, it should be noted in this embodiment that whether the blade shaft 801 or the matching structure of the connecting shaft body 802 and the shift lever shaft body 307 is adopted, the VGT component needs to be adapted to the high temperature air flow erosion environment of the exhaust gas when used in the supercharger. Therefore, the material hardness of the blade 8 is generally higher than that of the lever 3 to meet the strength and corrosion resistance of the blade 8 under gas erosion. At this time, compared to the case of using the blade shaft 801, on the one hand, the provision of the connecting shaft 802 on the blade 8 can undoubtedly significantly reduce the material consumption of the entire blade 8. Since the material of the blade 8 is more expensive, the cost of the blade 8 can be reduced cost. On the other hand, since the shift lever 3 adopts a material with lower hardness, not only the cost can be reduced, but also the wear between the shift lever shaft 307 and the mounting plate 1 can be reduced.

This embodiment is directed to a shift fork transmission unit composed of an adjusting pin 4, a shift fork 5 and a rocker shaft 7. As shown in FIGS. 16 and 17, one end of the shift fork 5 is configured with a shift fork groove 502, and The adjusting pin 4 fixedly connected to the dial 2 extends into the shift fork groove 502, and the rocker arm shaft 7 is connected to the other end of the shift fork 5 relative to the shift fork groove 502.

Among them, the adjusting pin 4 has an adjusting pin main body 401. One end of the adjusting pin main body 401 and the dial 2 can preferably be fixedly connected by interference press fitting, and the other end of the adjusting pin main body 401 extends into the shift fork groove 502. In addition, in this embodiment, a wear-resistant layer 402 integrally formed with the adjusting pin main body 401 is also configured on the outer peripheral surface of the adjusting pin main body 401 extending into the shift fork groove 502. The thickness k of the wear-resistant layer 402 should generally not be less than 0.15mm in design, and can be, for example, 0.15mm, 0.18mm, 0.2mm, etc. At the same time, if it matches the connection mode of the interference press, this embodiment is The outer peripheral side of the adjusting pin main body 401 can also preferably be constructed with a radially outwardly convex convex ring 4011, one side of the convex ring 4011 is connected with the wear-resistant layer 402, and the design of the convex ring 4011 facilitates the adjustment of the pin 4 Press-fitting on the dial 2 as a whole.

Of course, in addition to the press-fit connection, the adjustment pin main body 401 in the adjustment pin 4 can also be connected to the dial 2 by welding. In addition, it should be noted that, as mentioned above, the adjusting pin 4 is also preferably formed by a metal powder injection process, and as a wear-resistant structure, the wear-resistant layer 402 should be made of wear-resistant alloy, and the internal adjusting pin body 401 is General heat-resistant steel can be used. At this time, for wear-resistant alloys, for example, existing cobalt-based alloys, molybdenum-based alloys, or nickel-tungsten alloys can be used to withstand high temperatures above 600°C. For heat-resistant steels, it is convenient to choose existing suitable types of steel Yes, and because the wear-resistant layer 402 and the adjusting pin main body 401 together form an integral adjusting pin 4, attention should be paid to the material selection so that the adjusting pin main body 401 and the wear-resistant layer 402 have the same or similar coefficient of thermal expansion to ensure the adjustment The structure of the pin 4 is stable when heated.

By arranging the high-temperature resistant wear-resistant layer 402 on the adjusting pin 4, the adjusting pin 4 can exhibit good surface wear resistance and core toughness, and it can also achieve a small amount of wear-resistant alloy and reduce the cost of parts. Effect.

In this embodiment, with respect to the shift fork groove 502, a through hole 501 is formed at the other end of the shift fork 5, and the rocker shaft 7 is inserted and fixedly connected in the through hole 501, and specifically can be installed by interference press or welding. Realize the fixed connection between the two. In addition, in order to increase the thickness of the contact portion with the adjusting pin 4, so as to improve the wear resistance between the shift fork 5 and the adjusting pin 4, this embodiment is a preferred embodiment, and the shift forks 5 on opposite sides of the shift fork groove 502 A stepped portion 503 arranged oppositely is also constructed on the upper surface, and the portion of the adjusting pin 4 extending into the fork groove 502 is not higher than the top surface of the stepped portion 503.

In this embodiment, relative to the increased step portion 503, the thickness of the end of the shift fork 5 having the through hole 501 does not increase, so that the increase in weight of the shift fork 5 can be avoided, and the weight of the shift fork 5 can be reduced. In addition, further in this embodiment, the two opposite outer end faces of the shift fork 5 with one end of the shift fork groove 502 are also set to be convex, and at this time, the outer end faces of each convex are designed to be formed by the middle plane located in the middle. 504, and two circular arc surfaces 505 respectively connected to both sides of the middle plane 504. Therefore, the material can be reduced by adopting the circular arc section and the straight line section, and the effect of weight reduction is also achieved.

In this embodiment, as for the aforementioned roller 9, as mentioned above, the roller 9 can axially limit the dial 2 after being installed, thereby forming a limit structure in the VGT assembly. As shown in Figure 18 in conjunction with Figures 19 and 20, in addition to the roller 9, the limiting structure of this embodiment also includes a mounting hole 101 on the mounting plate 1 that is arranged through the mounting plate 1. The roller 9 is Connected in the mounting hole 101, and the limiting structure formed by the mounting hole 101 and the corresponding roller 9 is a plurality of groups arranged along the circumferential direction of the mounting plate 1.

In detail, the roller 9 is press-fitted into the mounting hole 101 from the side of the dial 2 through its own press-in end 903, and the roller 9 also has a head 901 partially blocked on the side of the dial 2 . In addition, the mounting hole 101 of this embodiment is designed as a stepped hole whose inner diameter increases along the pressing direction of the roller 9, and the inner diameter of the mounting hole 101 increases based on the stepped hole, so that the pressing of the roller 9 An annular air cavity Q is formed between the inlet end 903 and the inner wall of the mounting hole 101. One end of the air cavity Q is open, and the other end is closed due to the interference pressing of the roller 9.

In this embodiment, through the formation of the air cavity Q with one end closed, the gas cannot flow at the mounting hole 101, thereby alleviating the conduction of the heat at the blade 8 to the interference section of the mounting hole 101 and the press-in end 903, thereby reducing The roller 9 is at risk of loosening due to heat. In addition, in specific design, the radial thickness of the air cavity Q, that is, in the diameter direction of the press-in end 903 or the mounting hole 101, the distance between the outer wall of the press-in end 903 and the inner wall of the mounting hole 101 can generally be 0.3- Between 0.4 mm, and it may be 0.3 mm, 0.35 mm, 0.38 mm, or 0.4 mm, for example. The inventor found that when the radial thickness of the air cavity Q is in this range, both the mounting plate 1 and the roller 9 can have good structural performance, and the roller 9 can be effectively prevented from loosening due to heat. However, too large or too small radial thickness is detrimental to the structure and anti-loosening effect.

As shown in FIGS. 19 and 20, the mounting hole 101 of the stepped hole in this embodiment is specifically composed of a small-diameter hole section 1011 and a large-diameter hole section 1012, and as a preferred embodiment, and the mounting hole Similarly to 101, the outer diameter of the end portion of the press-in end 903 on the roller 9 is smaller, that is, the outer diameter of one part is smaller than the outer diameter of the other part, so that the press-in end 903 is also stepped. At this time, the press-in end 903 is specifically composed of a large-diameter shaft section 9031 and a small-diameter shaft section 9032, and for the outer diameter W of the large-diameter shaft section 9031, the outer diameter X of the small-diameter shaft section 9032, and the diameter of the small-diameter hole section 1011 The inner diameter P and the inner diameter L of the large-diameter hole section 1012 should satisfy that W is slightly larger than P and W smaller than L, and X is smaller than P and L.

It should be noted that the press-in end 903 and the mounting hole 101 provided in this embodiment can realize the fixed installation of the roller 9 in the mounting hole 101 through the interference fit of the large-diameter shaft section 9031 and the small-diameter hole section 1011. At the same time, Since the outer diameter of the small diameter shaft section 9032 is smaller than the outer diameter of the large diameter hole section 1012, the small diameter shaft section 9032 of the pressing-in end 903 of the roller 9 will not squeeze the large diameter hole section 1012 of the mounting hole 101 during interference press fitting. This can prevent the material around the mounting hole 101 on the mounting plate from protruding to the blade side due to extrusion, thereby avoiding jamming caused by interference with the blade 8.

Through the design of the small-diameter shaft section 9032, when the press-in end 903 is press-fitted into the mounting hole 101, it can be easily press-fitted. In order to ensure the stability of the fixed connection of the roller 9 in the mounting plate 1, and to avoid cracks in the part where the roller 9 is installed on the mounting plate 1, the press-in end 903 and the mounting hole 101 are generally in the axial direction of interference fit. The length, that is, the depth M of the small-diameter hole section 1011 can be between 3.8-4.5 mm, and for example, 3.8 mm, 4.0 mm, 4.2 mm, or 4.5 mm can be used. At the same time, the axial length S of the press-in end 903 in this embodiment should generally be smaller than the depth N of the mounting hole 101, and the axial length of the large-diameter shaft section 9031 can be greater than the depth of the small-diameter hole section 1011, that is, SY>M .

This embodiment is directed to the roller 9. As a further preferred embodiment, a protrusion 902 with an outer diameter smaller than that of the head 901 is also configured on the side where the head 901 of the roller 9 and the press-in end 903 are connected. The press-in end 903 is fixedly connected to the protruding portion 902, and as shown in FIG. 18, the outer peripheral side of the protruding portion 902 and the dial 2 are also spaced apart to make the protruding portion 902 It does not go beyond the outside of the mounting ring 102 mentioned below. In addition, due to the arrangement of the protruding portion 902 in this embodiment, a gap is formed between the head 901 and the blocked dial 2 so that the head 901 of the roller 9 is axially limited, and it is also convenient Can reduce the contact wear between the two. In order to make the bottom surface of the protruding portion 902 fit well on the mounting plate 1 after the roller 9 is installed, of course, in this embodiment, a circle of retracting knife can be provided at the contact portion of the press-in end 903 and the protruding portion 902. groove.

In order to perform the rotary installation of the dial 2, as an exemplary structure, in this embodiment, a convex mounting ring 102 is formed on the side of the mounting disk 1 that receives the dial 2, and the aforementioned mounting hole 101 penetrates The mounting ring 102 and the dial 2 are sleeved outside the mounting ring 102. In addition, in this embodiment, the mounting disk 1 outside the mounting ring 102 is also configured with an outer protrusion 103 arranged around the mounting ring 102, and the dial 2 sleeved outside the mounting ring 102 is axially supported on the outer protrusion 103 Above, in the same way, a gap can be formed between the end surface of the dial 2 and the mounting plate 1, and the contact wear between the two can be reduced.

In this embodiment, the installation of the VGT assembly in the supercharger is shown in Figure 21 and Figure 22. At this time, the mounting plate 1 is fixed on the housing, and the rear cover 10 is sleeved on the housing and can slide axially. Moreover, as a preferred embodiment, one end of the distance sleeve 6 is fixedly connected to the mounting plate 1 by interference press fitting or welding, and the other end of the distance sleeve 6 abuts against one side of the back cover 10 to achieve Support between the mounting plate 1 and the back cover 1.

In this embodiment, relative to the spacer 6, an elastic part is further provided on the other side of the back cover 10, and the elastic part elastically abuts between the back cover 10 and the housing, and it is also along the back cover 10 Circumferentially arranged in a ring shape. At this time, as an exemplary structure of the above-mentioned elastic portion, specifically, the elastic portion is an elastic pad 12 fitted on the shell, and the elastic pad 12 passes through the abutting surfaces a and the abutting surfaces on two opposite sides of the elastic pad. The surface b abuts against the back cover 10 and the housing, respectively.

At the same time, as an exemplary structure of the supercharger housing, the housing of this embodiment also includes a volute 11 and an intermediate housing 17 fixedly connected to the volute 11. The turbine 13 in the supercharger is rotatably installed relative to the volute 11 and the intermediate housing 17, the rear cover 10 and the elastic pad 12 are specifically sleeved on the volute 11, and the rear cover 10 can slide axially relative to the volute 11 At the same time, the inner side of the mounting plate 1 is sleeved on the intermediate housing 17, and the outer side of the mounting plate 1 is directly sandwiched between the volute 11 and the intermediate housing 17, so as to realize the installation of the mounting plate 1 in the supercharger housing It also guarantees the stability of the assembly of VGT components.

In this embodiment, the middle casing 17 and the volute 11 can be fixedly connected together by bolts 16, and when the volute 11 is connected to the middle casing 17, the two ends of the middle casing 17 connected to the volute 11 can be set as It can be sleeved together, so that the volute 11 and the intermediate casing 17 can be well centered, the assembly accuracy of the supercharger can be ensured, and the turbine 13 and the casing can be prevented from rubbing.

Regarding the above elastic pad 12, it is generally only necessary to use elastic heat-resistant steel, and the abutting surfaces a and b on both sides of the elastic pad 12 are also preferably ring-shaped arranged in the circumferential direction of the elastic pad 12, that is, The entire flat portion on each side of the elastic pad 12 is an abutting surface. At the same time, the abutting surface a abutting against the back cover 10 in this embodiment is also a circumferential setting corresponding to the connecting line between the spacers 6. That is, the two sides of the back cover 10 are respectively connected to the abutting surface a. And the distance sleeve 6 is within the same radial dimension range, so that the back cover 10 can maintain the force balance under the clamping of the distance sleeve 6 and the elastic pad 12 on both sides, and avoid serious deformation. .

Utilizing the arrangement of the spacers 6 and elastic pads 12 on both sides of the rear cover 10, when the exhaust gas entering the supercharger contains large particles in this embodiment, if the squeezing force formed by the large particles on the rear cover 10 exceeds the elasticity With the elastic force of the pad 12, the rear cover 10 will compress the elastic pad 12 and separate from the end surface of the spacer 6, thereby increasing the gap between the blade 8 and the rear cover 10, and between the mounting plate 1 and the rear cover 10. The distance, so that particles can be discharged under the action of the airflow, so as to reduce the chance of the blade 8 becoming stuck.

However, in this embodiment, the elastic pad 12 abuts against the volute 11 and the rear cover 10 through the annular abutment surfaces on both sides thereof. The arrangement of the elastic pad 12 can also be used to directly face the rear cover 10 and the volute 11 A certain sealing effect is generated between the two end faces to prevent exhaust gas from entering the turbine 13 through the gap between the rear cover 10 and the scroll 11.

Of course, in addition to the annular elastic pad 12, the elastic part of this embodiment can also adopt a plurality of elastic members located between the rear cover 10 and the volute 11. The elastic members may be springs, and each spring is also along the rear cover. 10 is uniformly distributed in the circumferential direction, so that the elastic part formed by the plurality of springs is arranged in an annular shape as a whole.

In addition, in addition to being constituted by a plurality of elastic members, of course, the above-mentioned elastic part can also be constituted by only one spring that is also sleeved on the scroll 11, and whether it is one spring or multiple springs, care should be taken to make the spring and the rear The abutting part of the cover 10 is set corresponding to the distance sleeve 6 on the other side, so as to ensure the balance of the forces on both sides of the back cover 10. Compared with the elastic pad 12, when a spring structure such as the one exemplified above is adopted, the aforementioned sealing effect formed between the back cover 10 and the scroll 11 will obviously be lost. Therefore, in the specific implementation, it is preferable to use Elastic pad 12.

In this embodiment, in addition to the seal formed by the elastic pad 12, in order to further improve the sealing performance between the rear cover 10 and the volute 11, a sealing ring is also provided between the radially contacting end surfaces of the volute 11 and the rear cover 10 19. At this time, specifically, an annular installation groove is provided at the position of the volute 11 for covering the rear cover 10, the sealing ring 19 is embedded in the installation groove, and preferably the sealing ring 19 may be two arranged side by side. To ensure the sealing effect.

In addition, the arrangement of the above-mentioned sealing ring 19 also makes the casing, that is, the volute 11 and the rear cover 10 do not contact in the radial direction, but is in a separated state, so that the rear cover 10 can be relative to the volute 11 Smooth axial movement. Furthermore, the radial support of the rear cover 10 by the sealing ring 19 can also prevent the rear cover 10 from shaking too much in the radial direction and causing the deformation of the exit position of the volute 11.

In this embodiment, a heat shield 14 is also provided on one side of the middle casing 17 to reduce the heat transfer of the exhaust gas to the other side. The heat shield 14 is specifically fixed between the middle casing 17 and the mounting plate 1. In addition, in order to ensure the sealing of the entire turbocharger housing, a sealing ring 18 is also sandwiched between the volute 11 and the intermediate housing 17 in this embodiment. The sealing ring 18 can be an existing V-shaped sealing ring. Of course, in addition to the V-shaped sealing ring, it can also adopt other existing sealing structures.

In addition, in order to facilitate the installation of the VGT assembly in the housing, a positioning pin 15 is also provided between the mounting plate 1 and the middle housing 17 in this embodiment. The two ends of the positioning pin 15 are respectively inserted into the mounting plate 1 and the middle housing. The housing 17 is used to connect the mounting plate 1 and the middle housing 17 together, and can play a role of limit during the assembly process. At this time, the hole on the mounting plate 1 for the positioning pin 15 to be inserted can be designed as a blind hole or a stepped through hole, and when a stepped through hole is used, attention should be paid to the inner diameter of the small diameter section in the through hole. It is smaller than the outer diameter of the positioning pin 15.

Of course, in addition to using the positioning pin 15, in this embodiment, a related external limiting structure can also be used to achieve the same limiting effect, and thus the positioning pin 15 is eliminated.

Through the application of the VGT component of this embodiment to the turbocharger, the rotation angle of each blade 8 can be adjusted synchronously based on the rotational speed of the engine, so that the cross-sectional area of the nozzle ring formed by each blade 8 is changed. The working state of the supercharger can be adjusted and the air intake of the engine can be adjusted, so that the air intake of the engine can be kept in a state that matches the working conditions of the vehicle engine to improve the working performance of the engine.

The above descriptions are only the preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the present disclosure. Within the scope of protection.

Claims

A VGT component limiting structure, used in a VGT component of a variable-section turbocharger, is characterized by:

The limit structure constitutes an axial limit for the rotation of the dial (2) provided on the mounting disk (1) in the VGT assembly,

The limiting structure includes a mounting hole (101) on the mounting plate (1) arranged through the mounting plate (1), and a roller (9) fixedly connected to the mounting hole (101),

The roller (9) is press-fitted in the mounting hole (101) through its own press-in end (903), and the roller (9) has a part blocked on one side of the dial (2) Head (901),

The mounting hole (101) is a stepped hole whose inner diameter increases along the pressing direction of the roller (9), and is pressed into the roller (9) due to the increase in the inner diameter of the mounting hole (101) An annular air cavity (Q) is formed between the end (903) and the inner wall of the mounting hole (101),

One end of the air cavity (Q) is open, and the other end is closed due to the interference pressing of the roller (9).
The VGT component limiting structure according to claim 1, wherein the outer diameter of a part of the end of the press-in end (903) is smaller than the outer diameter of the other part, so that the press-in end (903) is Stepped.
The VGT component limit structure according to claim 1, wherein the axial length of the interference fit between the press-in end (903) and the mounting hole (101) is between 3.8-4.5mm, and The axial length of the press-in end (903) is smaller than the axial depth of the mounting hole (101).
The VGT assembly limiting structure according to claim 1, characterized in that: the side of the head (901) connected to the press-in end (903) is configured with an outer diameter smaller than that of the head (901) A protruding portion (902), the press-in end (903) is fixedly connected to the protruding portion (902), and between the outer peripheral side of the protruding portion (902) and the dial (2) It is arranged at intervals, and due to the arrangement of the protruding part (902), a gap is formed between the head (901) and the blocked dial (2).
The VGT assembly limit structure according to claim 1, characterized in that: a convex mounting ring (102) is formed on one side of the mounting plate (1) that receives the dial plate (2), and The mounting plate (1) outside the mounting ring (102) is configured with an outer convex portion (103) arranged around the mounting ring (102), and the mounting hole (101) penetrates the mounting ring ( 102), the dial (2) is sleeved outside the mounting ring (102), and the dial (2) is axially supported on the outer convex portion (103), and is connected to the mounting ring (102). A gap is formed between the end surfaces of the disc (1).
The VGT assembly limiting structure according to any one of claims 1 to 5, wherein the radial thickness of the air cavity (Q) is between 0.3-0.4 mm.
A variable-section turbocharger VGT assembly used in a variable-section turbocharger, characterized in that:

The VGT assembly includes a mounting plate (1) and a back cover (10) arranged oppositely, a dial (2) that is arranged on the mounting plate (1), and is fixedly connected to the mounting plate (1) and/ Or the distance sleeve (6) on the back cover (10), and the VGT component limiting structure according to any one of claims 1 to 6 provided on the mounting plate (1),

The distance sleeve (6) is supported between the mounting plate (1) and the rear cover (10), and the distance sleeve (6) and the limiting structure are both along the dial plate (2) Multiple arranged at intervals in the circumferential direction;

The VGT assembly also includes a shift fork transmission unit that can receive an external rotational driving force to drive the dial (2) to rotate, and a plurality of blade units arranged at intervals along the circumference of the dial (2),

The blade unit has a blade (8) located between the mounting disk (1) and the rear cover (10), and constitutes a transmission connection between the blade (8) and the dial (2) The lever (3).
The variable-section turbocharger VGT assembly according to claim 7, wherein the blade (8) has a blade body (800), and a connecting shaft body (800) fixedly connected to the blade body (800). 802), a protrusion (301) at one end of the shift lever (3) is provided on one end surface of the shift lever (3), and a shift lever shaft at the other end relative to the protrusion (301) Body (307), and the shift lever shaft body (307) is provided with a connecting hole (308), and the connecting shaft body (802) is partially or completely interference press fitted in the connecting hole (308) to form The connection between the blade (8) and the shift lever (3).
The variable cross-section turbocharger VGT assembly according to claim 8, characterized in that: the shift lever (3) comprises a shift lever body (300) in the shape of a bar, and the shift lever body (300) One end is provided with a connecting portion to form a connection with the blade (8), and relative to the protrusion (301), on the other side of the lever main body (300), an inner recess is configured or penetrates the The material reduction part set by the lever (3).
The variable cross-section turbocharger VGT assembly according to claim 9, characterized in that: one end of the shift lever body (300) is configured to move toward the shift lever along the thickness direction of the shift lever body (300). A convex boss (3011) protruding from one side of the rod main body (300), and the boss (301) is located on the boss (3011).
The variable section turbocharger VGT assembly according to claim 10, characterized in that: the end of the shift lever (3) having the boss (3011) and one end of the boss (301) is The end plane (305) formed by the shift lever main body (300), the boss (3011) and the protrusion (301);

Relative to the protrusion (301) and one side of the shift lever shaft body (307), the end surface of the other side of the shift lever (3) is flat, and a top part is formed on the shift lever body (300) Plane (304).
The variable section turbocharger VGT assembly according to claim 7, characterized in that: the shift fork transmission unit includes an adjustment pin (4), the shift fork (5) and a rocker shaft (7), so One end of the shift fork (5) is configured with a shift fork groove (502), which is fixedly connected to the shift plate (2) and extends into the adjusting pin (4) in the shift fork groove (502). The arm shaft (7) is connected to the other end of the shift fork (5) relative to the shift fork groove (502).
The variable section turbocharger VGT assembly according to claim 12, wherein the adjusting pin (4) has an adjusting pin main body (401), and one end of the adjusting pin main body (401) is connected to the dial The disc (2) is fixedly connected, the other end extends into the fork groove (502), and the outer peripheral surface of the adjusting pin main body (401) that extends into the fork groove (502) is configured with The adjusting pin main body (401) is an integrally formed wear-resistant layer (402).
The variable-section turbocharger VGT assembly according to claim 7, characterized in that: the variable-section turbocharger has a casing, and a turbine (13) is rotated in the casing, so The mounting plate (1) is fixed on the housing, the back cover (10) is sleeved on the housing, the distance sleeve (6) is fixedly connected to the mounting plate (1), and One end abuts against one side of the back cover (10), and is provided with an elastic part sleeved on the housing on the other side of the back cover (10) relative to the distance sleeve (6) , The elastic part elastically abuts between the back cover (10) and the housing.
The variable cross-section turbocharger VGT assembly according to claim 14, characterized in that: the elastic part is an elastic pad (12) sleeved on the housing, and the elastic pad (12) passes through the The two abutting surfaces (a, b) on two opposite sides respectively abut the back cover (10) and the housing, and the abutting surfaces (a, b) on both sides of the elastic pad (12) b) All are ring-shaped arranged in the circumferential direction of the elastic pad (12), and the abutting surface (a) that abuts the back cover (10) corresponds to the interconnection between the spacers (6) A ring (19) is arranged between the shell and the end surface of the rear cover (10) that are in radial contact with each other.