CN219361019U - Automobile-used brake pedal feel analogue means - Google Patents

Abstract

The utility model provides a vehicle brake pedal feel simulation device, which comprises a body used for being connected with a valve body, wherein the body comprises a piston assembly and a connecting assembly which are connected in the axial direction, the piston assembly comprises a piston main body and a first elastic assembly, the connecting assembly comprises a connecting end cover and a second elastic assembly, the first elastic assembly comprises a spring seat, the spring seat is connected with the piston main body, a first elastic piece is arranged in the spring seat, the second elastic assembly comprises a second elastic piece, two ends of the second elastic piece are respectively connected with the spring seat and the connecting end cover, the piston main body can reciprocate in the axial direction relative to the connecting end cover, when the piston main body moves close to the connecting end cover, the first elastic piece and the second elastic piece are sequentially stressed and deformed, pedal feel can be fed back in time, the problem that the pedal feel is unreal due to hysteresis is reduced, and the use experience of a driver is ensured.

Description

Automobile-used brake pedal feel analogue means

Technical Field

The utility model relates to the field of pedal simulation devices, in particular to a brake pedal feel simulation device for a vehicle.

Background

The brake system is an important component of a vehicle operation system, the performance of the brake system directly affects the running and safety of the vehicle, the brake system is generally divided into two types, one type is a traditional brake system, the other type is an electronic hydraulic brake system, the traditional brake system generally comprises a vacuum booster, the system is complex, the integration level is poor, the electronic hydraulic brake system realizes the accurate control of the brake pressure through the hydraulic system, and compared with the traditional brake system, the electronic hydraulic brake system has better stability and wider application space.

The utility model discloses a pedal feel simulator, which is an important structure in an electronic hydraulic brake system and is used for carrying out feedback simulation on brake pedal feel of a driver, wherein comfort and response speed of the pedal feel directly influence use experience of the driver.

Disclosure of Invention

In view of the above, an object of the present utility model is to provide a brake pedal feel simulator for a vehicle, which has a good pedal feel and reduced hysteresis.

The utility model provides a vehicle brake pedal feel simulation device, which comprises a body used for being connected with a valve body, wherein the body comprises a piston assembly and a connecting assembly which are connected in the axial direction, the piston assembly comprises a piston main body and a first elastic assembly, the connecting assembly comprises a connecting end cover and a second elastic assembly, the piston assembly and the connecting assembly are connected through the first elastic assembly and the second elastic assembly, the first elastic assembly comprises a spring seat, the spring seat is connected with the piston main body, a first elastic piece is arranged in the spring seat, the second elastic assembly comprises a second elastic piece, two ends of the second elastic piece are respectively connected with the spring seat and the connecting end cover, the piston main body can reciprocate in the axial direction relative to the connecting end cover, and when the piston main body moves close to the connecting end cover, the first elastic piece and the second elastic piece are stressed and deformed in sequence.

In an embodiment, the piston body includes a first accommodation cavity, the first elastic component includes a deformation piece, the deformation piece includes a base piece and an abutment piece, the deformation piece passes through the base piece is installed in the first accommodation cavity, the abutment piece sets up to round platform form, the great one end of abutment piece radial dimension with the base piece is connected.

In one embodiment, the spring seat includes a spacer and a base, the spacer is connected with the piston body, and the first elastic member is installed between the spacer and the base.

In an embodiment, the base includes a positioning member and a resisting member, the radial dimension of the resisting member is greater than the radial dimension of the positioning member, the resisting member is located at one end of the positioning member near the piston main body, and is used for being connected with the piston main body, one end of the second elastic member is sleeved on the positioning member, and the end of the second elastic member is abutted to the resisting member.

In an embodiment, the positioning member includes a cavity for accommodating the first elastic member, the first elastic member is installed in the cavity, an end of the first elastic member contacts with the spacer, and when the first elastic member is in a free state, a first movement gap is left between the spacer and the base.

In an embodiment, the connecting end cover comprises a second accommodating cavity, the second elastic component comprises a second elastic component and a fixing component, one end of the fixing component is fixedly connected with the connecting end cover, the other end of the fixing component is movably connected with the piston main body, a third movement gap is reserved between the fixing component and the deformation component, the second elastic component and the fixing component are arranged in the second accommodating cavity, the second elastic component is sleeved on the fixing component, and when the second elastic component is arranged in the second accommodating cavity in a free state, a second movement gap is reserved between the spring seat and the connecting end cover.

In an embodiment, the gasket, the base is provided with a through hole matched with the fixing piece, and the gasket, the first elastic piece and the base are sequentially sleeved on the fixing piece.

In an embodiment, a clamping piece is arranged at one end part of the fixing piece, which is close to the piston main body, the radial dimension of the clamping piece is larger than the aperture dimension of the through hole, and one end of the abutting piece, which is smaller in radial dimension, is used for being in contact with the clamping piece.

In an embodiment, a clamping protrusion is arranged at the bottom of the second accommodating cavity, and the second elastic piece is sleeved on the clamping protrusion.

In an embodiment, the clamping protrusion is provided with a receiving hole, and one end of the fixing piece is installed in the receiving hole.

The utility model has the beneficial effects that:

through setting up first elastic component and second elastic component, make the piston main part when moving for connecting the end cover, can produce damping force, reaction piston main part, feedback to brake pedal department through the piston main part, and then form the footboard and feel feedback, the setting of spring holder, be used for installing first elastic component, and, the cooperation is connected the end cover and is spacing and fixed the both ends of second elastic component, guarantee the installation quality of second elastic component, when the piston main part is being close to the motion of connecting the end cover, first elastic component and second elastic component atress in proper order, if trample the power is less, will only first elastic component atress, provide less damping force, when trampling the power great, first elastic component atress first section damping force is provided, then the second elastic component atress provides bigger damping force, so set up, can in time feedback the footboard sense, reduce the unreal problem of footboard sense that the hysteresis quality brought, ensure driver's use experience.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an overall structure of an embodiment of the present utility model;

FIG. 2 is an exploded view of an embodiment of the present utility model;

FIG. 3 is a cross-sectional view of an embodiment of the present utility model;

FIG. 4 is a schematic structural view of a deforming member according to an embodiment of the present utility model;

FIG. 5 is a schematic view of a spring seat according to an embodiment of the present utility model;

fig. 6 is a hydraulic schematic of an embodiment of the present utility model.

In the figure:

10-a body;

a 20-piston assembly; 21-a piston body; 211-a first accommodation chamber; 22-deformation; 221-a base; 222-an abutment; 223-groove; 23-spring seats; 231-a gasket; 2311-a bump; 232-a first elastic member; 233-a base; 2331-a positioning member; 2332-a retaining member;

30-a connection assembly; 31-connecting an end cap; 311-a second accommodation chamber; 312-snap-fit protrusions; 313-receiving holes; 32-a second elastic member; 33-fixing piece; 331-a clip;

40-valve body; 41-a first sealing ring; 42-a second sealing ring;

51-adjusting fork; 511-push rod; 52-a master cylinder; 521-master cylinder chamber; 53-load chamber; 54-a liquid storage tank; 55-electromagnetic valve; 56-one-way valve.

Detailed Description

Specific embodiments of the present utility model will be described in detail below with reference to the accompanying drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the utility model. All other embodiments, which can be made by those skilled in the art without making any inventive effort, are intended to be within the scope of the present utility model.

In the description of the present utility model, unless explicitly stated and limited otherwise, the terms "disposed," "mounted," "connected," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms described above will be understood to those of ordinary skill in the art in a specific context.

The terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," and the like are used as references to orientations or positional relationships based on the orientation or positional relationships shown in the drawings, or the orientation or positional relationships in which the inventive product is conventionally disposed in use, merely for convenience of description and simplicity of description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore are not to be construed as limiting the utility model.

The terms "first," "second," "third," and the like, are merely used for distinguishing between similar elements and not necessarily for indicating or implying a relative importance or order.

The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a list of elements does not include only those elements but may include other elements not expressly listed.

Referring to fig. 1 and 2, the brake pedal feel simulation device for a vehicle according to the present utility model includes a body 10, the body 10 includes a piston assembly 20 and a connecting assembly 30 connected in an axial direction, the piston assembly 20 includes a piston main body 21 and a first elastic assembly, the connecting assembly 30 includes a connecting end cap 31 and a second elastic assembly, the piston main body 21 and the connecting end cap 31 are connected through the first elastic assembly and the second elastic assembly, and the piston main body 21 is configured to be capable of reciprocating in the axial direction with respect to the connecting end cap 31.

It will be appreciated that the piston body 21, the first elastic member, the second elastic member and the connecting end cap 31 are connected in the axial direction and coaxially disposed.

As shown in fig. 3, the body 10 is configured to be connected to the valve body 40, more specifically, the piston assembly 20 and a part of the connecting assembly 30 are accommodated in a chamber of the valve body 40, and for convenience of connection, a radially outermost surface of the connecting end cap 31 is provided with threads, and an inner wall of the chamber of the valve body 40 is provided with threads, so that the connection between the body 10 and the valve body 40 is achieved by means of threaded connection.

Further, the piston main body 21 is sleeved with the first sealing ring 41 along the radially outermost surface, an annular groove (not shown in the figure) for accommodating the first sealing ring 41 is formed in the inner wall of the chamber of the valve body 40, the first sealing ring 41 is accommodated in the annular groove, the tightness between the piston main body 21 and the valve body 40 is improved through the first sealing ring 41, the hydraulic leakage inside the valve body 40 is prevented, meanwhile, external dust and impurities can be prevented from entering the valve body 40, and the service life of the valve body 40 is ensured.

Furthermore, the second sealing ring 42 is sleeved on the radially outermost surface of the connecting end cover 31, an annular groove (not shown in the figure) for accommodating the second sealing ring 42 is formed in the inner wall of the chamber of the valve body 40, the second sealing ring 42 is accommodated in the annular groove, the tightness between the connecting end cover 31 and the valve body 40 is increased through the second sealing ring 42, the hydraulic leakage inside the valve body 40 is prevented, meanwhile, external dust and impurities can be prevented from entering the valve body 40, and the service life of the valve body 40 is ensured.

In one example of this embodiment, the radial dimension of the piston body 21 is smaller than the radial dimension of the connecting end cap 31.

As shown in fig. 2 and 3, the piston main body 21 includes a first accommodating chamber 211, an opening is provided at one end of the first accommodating chamber 211 along the axial direction of the piston main body 21, the first elastic assembly includes a deformation member 22 and a spring seat 23, the deformation member 22 is located in the first accommodating chamber 211, the spring seat 23 is connected with one end of the piston main body 21 along the axial direction, and the spring seat 23 is located at one end of the opening of the first accommodating chamber 211.

In an example of the present embodiment, as shown in fig. 4, the deformation member 22 includes a base member 221 and an abutment member 222, the base member 221 is located at the bottom of the abutment member 222, the deformation member 22 is in interference fit with the first accommodating cavity 211 through the base member 221, the deformation member 22 is disposed in the first accommodating cavity 211 in an interference fit manner, the abutment member 222 is a truncated cone-shaped member, and one end with a larger radial dimension is connected with the base member 221.

In one example, the deforming member 22 is made of rubber.

In one example, the base 221 is integrally formed with the abutment 222.

In one example, the base 221 is provided with the groove 223 along the radial outermost surface, and the deformation piece 22 is made of rubber material through the arrangement of the groove 223, so that when the base 221 is installed in the first accommodating cavity 211 in an interference manner, the base 221 is deformed due to extrusion with the cavity wall of the first accommodating cavity 211, and the deformation amount of the base 221 can be absorbed through the arrangement of the groove 223, so that the deformation piece 22 is stably and efficiently installed in the first accommodating cavity 211, and the installation quality is ensured.

In one example, the groove 223 is provided as an arcuate groove.

In one example, the grooves 223 are provided in three and uniformly distributed on the radially outermost surface of the base member 221 for best absorbing deformation.

As shown in fig. 2, the spring seat 23 includes a spacer 231, a first elastic member 232, and a base 233. The first elastic member 232 is disposed between the spacer 231 and the base 233, and the spacer 231 and the base 233 cooperate to limit the first elastic member 232 in the axial direction, and the first elastic member 232 is illustratively a spring.

In one example, referring to fig. 2, 3 and 5, a protrusion 2311 is disposed on an end surface of the gasket 231 near the base 233, the protrusion 2311 is matched with an inner diameter of the first elastic member 232, and the first elastic member 232 is sleeved on the protrusion 2311.

In one example, referring to fig. 2, 3 and 5, the base 233 includes a positioning member 2331 and a resisting member 2332, the positioning member 2331 is configured to be cylindrical, the resisting member 2332 is located at an end of the positioning member 2331 near the piston main body 21 and is used for being connected with the piston main body 21, a radial dimension of the resisting member 2332 is larger than a radial dimension of the positioning member 2331, the positioning member 2331 is convexly located at an end of the resisting member 2332 near the connecting end cover 31, the positioning member 2331 includes a cavity for accommodating the first elastic member 232, the first elastic member 232 is installed in the cavity, and an end portion of the first elastic member 232 is in contact with the gasket 231.

As shown in fig. 3, when the first elastic member 232 is mounted on the base 233 in a free state, one end of the first elastic member 232, which is close to the gasket 231, protrudes out of the cavity of the base 233, so that a first movement gap is left between the gasket 231 and the base 233.

Referring to fig. 2 and 3, the connecting end cover 31 includes a second accommodating cavity 311, an opening is formed at one end of the second accommodating cavity 311 along the axial direction of the connecting end cover 31, a second elastic component is installed in the second accommodating cavity 311, the second elastic component includes a second elastic member 32 and a fixing member 33, the fixing member 33 is installed between the piston main body 21 and the connecting end cover 31, one end of the fixing member 33 is fixedly connected with the connecting end cover 31, the other end is movably connected with the piston main body 21, the second elastic member 32 is sleeved on the fixing member 33, one end of the second elastic member 32 is in contact with the cavity bottom of the second accommodating cavity 311, the other end is sleeved on the spring seat 23, more specifically, a positioning member 2331 is matched with the inner diameter of the second elastic member 32, the second elastic member 32 is sleeved on the positioning member 2331, the radial dimension of the resisting member 2332 is larger than the outer diameter dimension of the second elastic member 32, and the two ends of the second elastic member 32 are limited by the cooperation of the spring seat 23 and the fixing member 33 and the connecting end cover 31, so that the setting of the second elastic member 32 is ensured to be stable.

Illustratively, the second resilient member 32 is provided as a spring, and the outer diameter of the first resilient member 232 is smaller than the outer diameter of the second resilient member 32.

In one example, when the second elastic member 32 is installed in the second accommodating cavity 311 in a free state, the end portion of the second elastic member 32 protrudes out of the second accommodating cavity 311, so that a second movement gap is left between the spring seat 23 and the connecting end cover 31.

Referring to fig. 2 and 3, through holes are formed in the gasket 231 and the base 233, the fixing member 33 is installed in the through holes, a clamping member 331 is disposed at an end, close to the piston assembly 20, of the fixing member 33, a radial dimension of the clamping member 331 is greater than a hole dimension of the through hole in the gasket 231, and when the assembly is performed, an end, not provided with the clamping member 331, of the fixing member 33 sequentially penetrates through the gasket 231, the first elastic member 232, the base 233 and the second elastic member 32 to be connected with the connecting end cover 31, so that the clamping member 331 contacts with the gasket 231.

It will be appreciated that, since the spacer 231 is connected to the piston body 21, the clamping member 331 is located on a side of the spacer 231 near the piston body 21, and therefore, the clamping member 331 will be accommodated in the first accommodating cavity 211, and for convenience of assembly, the clamping member 331 is in clearance fit with the first accommodating cavity 211, so as to prevent the clamping member 331 from obstructing the movement of the piston body 21.

In an example of this embodiment, a positioning groove (not labeled in the drawing) is disposed at an end of the clamping member 331 near the piston main body 21, and the positioning groove is disposed in cooperation with the deforming member 22, more specifically, the positioning groove is disposed in cooperation with an end of the abutting member 222 with a smaller radial dimension, so as to perform a positioning function on the deforming member 22, and after the assembly of the body 10 is completed, a third movement gap is left between an end of the deforming member 22 and the clamping member 331.

In an example of this embodiment, as shown in fig. 3, a bottom of the second accommodating cavity 311 is provided with a clamping protrusion 312, the clamping protrusion 312 is matched with an inner diameter of the second elastic member 32, and the second elastic member 32 is sleeved on the clamping protrusion 312.

The clamping protrusion 312 is provided with a receiving hole 313, the receiving hole 313 is matched with the end part of the fixing piece 33, the fixing piece 33 is arranged in the receiving hole 313, and the fixing piece 33 is in interference fit with the receiving hole 313.

As shown in fig. 5, the brake system of the pedal comprises an adjusting fork 51, a main cylinder 52, a load cavity 53 and a liquid storage tank 54, wherein the main cylinder 52 comprises a main cylinder cavity 521, a piston is arranged in the main cylinder cavity 521, the adjusting fork 51 is connected with the brake pedal, the adjusting fork 51 is connected with the piston in the main cylinder cavity 521 through a push rod 511, the main cylinder 52 is connected with the load cavity 53 through a liquid path, an electromagnetic valve 55 is arranged between the liquid paths, the main cylinder 52, the load cavity 53 and the liquid storage tank 54 are connected through the liquid path, and a one-way valve 56 is arranged at the liquid storage tank 54.

The principle of operation of the body 10 will now be described with reference to fig. 5:

when a driver presses a brake pedal, the adjusting fork 51 pushes a piston through the push rod 511, the piston presses oil in the main cylinder cavity 521, the electromagnetic valve 55 is controlled to be opened, the oil in the main cylinder cavity 521 is transmitted to the load cavity 53 through an oil path, the one-way valve 56 is closed, a closed liquid path is formed between the main cylinder 52 and the load cavity 53, the oil cannot be discharged to the liquid storage tank 54, and along with the gradual increase of the stepping force applied to the brake pedal, the hydraulic pressure is also gradually increased and is applied to the piston main body 21;

the piston main body 21 is hydraulically pushed to move towards the side close to the connecting end cover 31, the piston main body 21 drives the gasket 231 to move together, the first elastic piece 232 is stressed to compress, the first movement gap is gradually reduced, the deformation piece 22 moves together with the piston main body 21, the third movement gap is gradually reduced until the gasket 231 contacts with the base 233, the deformation piece 22 contacts with the clamping piece 331, and the first elastic piece 232 is not compressed any more;

as the force applied to the brake pedal increases, the piston main body 21 moves together with the spring seat 23, the positioning member 2331 applies a force to the second elastic member 32, the second elastic member 32 is compressed under a force, the second movement gap gradually decreases, the deformation member 22 and the clamping member 231 are pressed, the deformation member 22 is deformed, the first elastic member 232, the second elastic member 32 and the deformation member 22 together form a damping force, and the damping force is fed back to the brake pedal to form pedal feel feedback.

Through the setting of first elastic component, make brake pedal's atress obtain feedback immediately, reduce the hysteresis quality, can provide true, timely footboard sense, the use of driver is experienced well.

In summary, through setting up first elastic component and second elastic component, make piston main part 21 when moving for connecting end cover 31, can produce the damping force, reaction piston main part 21, feedback to brake pedal department through piston main part 21, and then form pedal feel feedback, the setting of spring holder 23, be used for installing first elastic component 232, and cooperate connecting end cover 31 to carry out spacing and fixed to the both ends of second elastic component 32, guarantee the installation quality of second elastic component 32, when piston main part 21 is being done the motion near connecting end cover 31, first elastic component 232 and second elastic component 32 atress in proper order, if the stepping force is less, will only first elastic component 232 atress, provide less damping force, when the stepping force is great, first elastic component 232 atress earlier, provide first section damping force, then second elastic component 32 atress provides bigger damping force, so set up, can in time feedback pedal feel, reduce the problem that the pedal feel that the hysteresis brought is unreal, ensure driver's use experience.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present utility model should be included in the present utility model. Accordingly, the scope of the utility model should be assessed as that of the appended claims.

Claims (10)

1. The utility model provides a vehicle brake pedal feel analogue means which characterized in that: including body (10) that are used for being connected with valve body (40), body (10) include piston assembly (20) and coupling assembling (30) of following axial connection, piston assembly (20) include piston main part (21) and first elastic component, coupling assembling (30) are including connecting end cover (31) and second elastic component, piston assembly (20) with coupling assembling (30) are through first elastic component with second elastic component connects, piston main part (21) are configured to, can for connecting end cover (31) along axial reciprocating motion, first elastic component includes spring holder (23), spring holder (23) with piston main part (21) are connected, be equipped with first elastic component (232) in spring holder (23), second elastic component includes second elastic component (32), the both ends of second elastic component (32) respectively with spring holder (23) and coupling end cover (31) are connected.

2. The brake pedal feel simulator for vehicles according to claim 1, wherein: the piston main body (21) comprises a first accommodating cavity (211), the first elastic component comprises a deformation piece (22), the deformation piece (22) comprises a base piece (221) and an abutting piece (222), the deformation piece (22) is arranged in the first accommodating cavity (211) through the base piece (221), the abutting piece (222) is in a round table shape, and one end of the abutting piece (222) with a larger radial size is connected with the base piece (221).

3. The brake pedal feel simulator for vehicles according to claim 2, wherein: the spring seat (23) comprises a gasket (231) and a base (233), the gasket (231) is connected with the piston main body (21), and the first elastic piece (232) is arranged between the gasket (231) and the base (233).

4. A brake pedal feel simulation device for a vehicle according to claim 3, wherein: the base (233) comprises a positioning piece (2331) and a resisting piece (2332), the radial size of the resisting piece (2332) is larger than that of the positioning piece (2331), the resisting piece (2332) is located at one end, close to the piston main body (21), of the positioning piece (2331) and used for being connected with the piston main body (21), one end of the second elastic piece (32) is sleeved on the positioning piece (2331), and the end portion of the second elastic piece (32) is abutted to the resisting piece (2332).

5. The brake pedal feel simulator for vehicles according to claim 4, wherein: the locating piece (2331) comprises a cavity for accommodating the first elastic piece (232), the first elastic piece (232) is arranged in the cavity, the end part of the first elastic piece (232) is in contact with the gasket (231), and when the first elastic piece (232) is in a free state, a first movement gap is reserved between the gasket (231) and the base (233).

6. The brake pedal feel simulator for vehicles according to claim 4, wherein: the connecting end cover (31) comprises a second accommodating cavity (311), the second elastic component comprises a second elastic component (32) and a fixing component (33), one end of the fixing component (33) is fixedly connected with the connecting end cover (31), the other end of the fixing component is movably connected with the piston main body (21), a third movement gap is reserved between the fixing component and the deformation component (22), the second elastic component (32) and the fixing component (33) are arranged in the second accommodating cavity (311), the second elastic component (32) is sleeved on the fixing component (33), and when the second elastic component (32) is arranged in the second accommodating cavity (311) in a free state, a second movement gap is reserved between the spring seat (23) and the connecting end cover (31).

7. The vehicular brake pedal feel simulation device according to claim 6, wherein: the gasket (231) and the base (233) are provided with through holes matched with the fixing piece (33), and the gasket (231), the first elastic piece (232) and the base (233) are sequentially sleeved on the fixing piece (33).

8. The brake pedal feel simulator for vehicles according to claim 7, wherein: one side end part of the fixing piece (33) close to the piston main body (21) is provided with a clamping piece (331), the radial size of the clamping piece (331) is larger than the aperture size of the through hole, and one end of the abutting piece (222) with smaller radial size is used for being in contact with the clamping piece (331).

9. The vehicular brake pedal feel simulation device according to claim 6, wherein: the cavity bottom of the second accommodating cavity (311) is provided with a clamping protrusion (312), and the second elastic piece (32) is sleeved on the clamping protrusion (312).

10. The vehicular brake pedal feel simulation device according to claim 9, wherein: the clamping protrusion (312) is provided with a containing hole (313), and one end of the fixing piece (33) is arranged in the containing hole (313).