Constant amplitude adjusting method and system for pressure pulse of drilling tool

A constant amplitude adjusting method and system for pressure pulse of drilling tool including obtaining a current flow velocity value of mud at the rear of a pressure pulse generator in the drilling tool, and sending the current flow velocity value to a controller; the controller compares the current flow velocity value with a preset flow velocity value, and sends an adjustment instruction to the pressure pulse generator according to the comparison result; the pressure pulse generator adjusts the opening degree according to the adjustment instruction of the controller. The adjusting system comprising a pressure pulse generator for generating a pressure pulse wave, and the opening degree is adjustable.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese Patent Application No. 201811639916.6 filed Dec. 29, 2018, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The disclosure relates to constant amplitude adjusting method and system for pressure pulse of drilling tool, and pertains to the technical field of drilling.

BACKGROUND

The measurement-while-drilling (MWD) technology enables real-time transmission of measurement-while-drilling geological logging parameters, well trajectory parameters, drilling parameters and other data to a ground monitoring system during drilling. Drilling engineers and geological analysis engineers make timely decisions and adjust the well trajectory in real time according to the current real-time well trajectory parameters and the geological parameters of the strata near a drill bit, so that the drill bit is always drill in the oil and gas formation to maximize the drilling rate and recovery ratio of the hydrocarbon reservoir.

In the current technologies, a pressure pulse generator is arranged in a drill collar. When the mud flows through the pressure pulse generator, the pressure pulse generator generates pressure pulse waves, and the ground device decodes the pressure pulse waves after receiving them. Thereby, the well trajectory of the underground oil well and the reservoir geological information are obtained.

At present, during the drilling process, the mud flow needs to be adjusted due to the drilling technology, which causes the amplitude of the pressure pulse wave to change. Since the drilling depth is usually very deep, when the amplitude of the pressure pulse wave decreases, it is difficult to decode when being transmitted to the ground, thus affecting the speed and accuracy of decoding. The opening degree of a conventional pressure pulse generator needs to be pre-adjusted before drilling, and it cannot be automatically adjusted during the drilling process, and thus downstream communication is required, which occupies a certain drilling time. Therefore, there is an immediate need to develop a constant amplitude automatic maintenance technology for mud pulse pressure waves that can adapt to changes in well flow.

SUMMARY OF DISCLOSURE

An aspect of the present disclosure is to provide a constant amplitude adjusting method for pressure pulse of drilling tool, which can adjust the opening degree of a pressure pulse generator according to the change of the mud flow velocity, thereby generating a constant amplitude pressure pulse wave to solve the problem in the current technologies.

Another aspect of the present disclosure is to provide a constant amplitude adjusting system for pressure pulse of drilling tool, which is capable of realizing the above adjusting method, so that the opening degree of the pressure pulse generator can be adjusted according to requirements, to ensure constant amplitude pressure pulse wave.

The disclosure provides a constant amplitude adjusting method for pressure pulse of drilling tool, comprising the following steps:

step a, obtaining a current flow velocity value of mud at the rear of a pressure pulse generator in the drilling tool, and sending the current flow velocity value to a controller;

step b, the controller compares the current flow velocity value with a preset flow velocity value, and sends an adjustment instruction to the pressure pulse generator according to a comparison result;

step c, the pressure pulse generator adjusts an opening degree according to the adjustment instruction of the controller.

In the aforementioned constant amplitude adjusting method for pressure pulse of drilling tool, preferably, in the step b:

when the current flow velocity value is equal to the preset flow velocity value, step a and step b are repeatedly performed;

when the current flow velocity value is less than the preset flow velocity value, the controller sends an instruction of increasing the opening degree to the pressure pulse generator; and

when the current flow velocity value is greater than the preset flow velocity value, the controller sends an instruction of decreasing the opening degree to the pressure pulse generator.

In the aforementioned constant amplitude adjusting method for pressure pulse of drilling tool, preferably, the method further comprises step d, after completing the step c, obtaining a current pressure value of the mud at the rear of the pressure pulse generator in the drilling tool, and sending the current pressure value to the controller, the controller compares the current pressure value with a preset pressure value, and sends an adjustment instruction to the pressure pulse generator according to a comparison result, the pressure pulse generator adjusts the opening degree according to the adjustment instruction of the controller again.

In the aforementioned constant amplitude adjusting method for pressure pulse of drilling tool, preferably, in the step d,

when the current pressure value is greater than the preset pressure value, the controller controls the pressure pulse generator to decrease the opening degree;

when the current pressure value is less than the preset pressure value, the controller controls the pressure pulse generator to increase the opening degree; and

when the current pressure value is equal to the preset pressure value, step a is performed.

A constant amplitude adjusting system for pressure pulse of drilling tool, comprising:

a pressure pulse generator that is arranged in a drill collar for generating a pressure pulse wave, where an opening degree of the pressure pulse generator is adjustable;

a flow measuring apparatus that is arranged at the rear of the pressure pulse generator for measuring a current flow velocity value of mud at the rear of the pressure pulse generator; and

a controller that is configured to receive the current flow velocity value measured by the flow measuring apparatus, and compare the current flow velocity value with a preset flow velocity value, and send an opening degree adjustment instruction to the pressure pulse generator according to a comparison result.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, the flow measuring apparatus comprises an impeller and a first angle sensor, and the first angle sensor is installed in the impeller.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, a generator assembly is further included, the generator assembly is electrically connected to the controller, and a rotor of the generator assembly is fixedly connected to the impeller.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, the pressure pulse generator comprises a motor, a valve seat, a valve core, a screw rod and a mounting sleeve, wherein the drill collar has a motor mounting cavity, and the motor is mounted in the motor mounting cavity, the screw rod is fixedly mounted on a rotating shaft of the motor, the mounting sleeve is screwed with the screw rod, and the valve core is fixedly connected with the mounting sleeve, the valve seat is fixed in the drill collar, the drill collar is provided with a mounting seat, and the mounting sleeve is movably connected to the mounting seat, and the mounting seat is used to limit the degree of freedom in a circumferential direction of the mounting sleeve.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, the pressure pulse generator comprises a motor, a valve seat and an adjusting plate, wherein the drill collar has a motor mounting cavity, and the motor is mounted in the motor mounting cavity, the valve seat is fixed in the drill collar, and the adjusting plate is fixedly mounted on a rotating shaft of the motor, and the valve seat and the adjusting plate are respectively provided with through holes.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, a second angle sensor is mounted at a rear end of the rotating shaft.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, a pressure measuring mechanism is further included and is provided on an outer sidewall of the drill collar, the pressure measuring mechanism comprises a sensor assembly and a sealing member, a mounting groove is formed in the outer sidewall of the drill collar, the sealing member is fastened to the mounting groove and fixed by bolts, and the sensor assembly is fixedly mounted in the mounting groove, a liquid inlet hole communicating with a central flow channel of the drill collar is provided in the mounting groove, and a liquid inlet end of the sensor assembly is communicatively connected with the liquid inlet hole.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, the mounting groove comprises a first groove body and a second groove body, and the second groove body is arranged on the bottom of the first groove body, the sealing member comprises a cover portion and a limiting portion which are of an integrated structure, the shape and size of the cover portion are correspondingly identical to the shape and size of the first groove body, and the shape and size of the limiting portion are correspondingly identical to the shape and size of the second groove body, a stepped hole is formed in each of the two ends of the cover portion, and threaded holes corresponding to the stepped holes are formed in the first groove body.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, a lower holding groove is arranged on the bottom of the second groove body, an upper holding groove is arranged on the bottom of the limiting portion, the upper holding groove and the lower holding groove are oppositely disposed, the sensor assembly is mounted in a space formed by the upper holding groove and the lower holding groove, and one end of the liquid inlet hole is located in the lower holding groove, and the other end of the liquid inlet hole is communicatively connected with the center flow channel.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, a wire harness hole is further included, one end of the wire harness hole is located in the lower holding groove, and the other end of the wire harness hole is communicatively connected with a wire routing hole of the drill collar.

In the aforementioned constant amplitude adjusting system for pressure pulse of drilling tool, preferably, the sensor assembly comprises a sheath, a connector and a sensor, wherein a first mounting hole is radially formed in a sidewall of one end of the sheath, a second mounting hole is axially formed in the other end of the sheath, the first mounting hole and the second mounting hole are communicatively connected through a flow channel, one end of the connector is fixedly mounted in the first mounting hole, and the sensor is fixedly mounted in the second mounting hole.

Compared with the current technologies, the present disclosure provides a constant amplitude adjusting method for pressure pulse of drilling tool, which determines how to adjust the opening degree of the pressure pulse generator by measuring the flow velocity of the mud in the drilling tool in real-time, and enables the constant amplitude pressure pulse wave by the opening degree adjustment of the pressure pulse generator, thereby solving the problem of increasing decoding difficulty caused by the instability of the amplitude of the pressure pulse wave in the prior art.

The disclosure also provides a constant amplitude adjusting system for pressure pulse of drilling tool, comprising: a pressure pulse generator, a flow measuring apparatus and a controller, wherein the controller receives a current flow velocity value of mud measured by the flow measuring apparatus and compares the current flow velocity value with a preset flow velocity value, and sends an opening degree adjustment instruction to the pressure pulse generator, thereby realizing the opening degree adjustment of the pressure pulse generator, so that the amplitude of the pressure pulse wave generated by the pressure pulse generator is constant.

DESCRIPTION OF EMBODIMENTS

The embodiments described with reference to the drawings below are only exemplary, and are only intended to explain rather than to limit the present disclosure.

Embodiments of the disclosure: a constant amplitude adjusting method for pressure pulse of drilling tool, comprising the following steps:

step a, obtaining a current flow velocity value of mud at the rear of a pressure pulse generator in a drilling tool, and sending the current flow velocity value to a controller;

step b, the controller compares the current flow velocity value with a preset flow velocity value, and sends an adjustment instruction to the pressure pulse generator according to a comparison result. The specific method for comparison between the current flow velocity value and the preset flow velocity value is:

when the current flow velocity value is equal to the preset flow velocity value, step a and step b are repeatedly performed;

when the current flow velocity value is less than the preset flow velocity value, the controller sends an instruction of increasing the opening degree to the pressure pulse generator;

when the current flow velocity value is greater than the preset flow velocity value, the controller sends an instruction of decreasing the opening degree to the pressure pulse generator; and

step c, the pressure pulse generator adjusts the opening degree according to the adjustment instruction of the controller.

Generally speaking, the constant amplitude pressure pulse wave can be realized after step c is completed. To improve the working accuracy of the present disclosure, in a preferred embodiment, a fine adjustment method is further added, specifically comprising step d: after completing the step c, obtaining the current pressure value of the mud at the rear of the pressure pulse generator in the drilling tool, and sending the current pressure value to the controller, the controller compares the current pressure value with a preset pressure value, and sends an adjustment instruction to the pressure pulse generator according to the comparison result, and the pressure pulse generator adjusts the opening degree according to the adjustment instruction of the controller again;

when the current pressure value is greater than the preset pressure value, the controller controls the pressure pulse generator to decrease the opening degree;

when the current pressure value is less than the preset pressure value, the controller controls the pressure pulse generator to increase the opening degree; and

when the current pressure value is equal to the preset pressure value, step a is performed to proceed to the next adjustment cycle.

Hereinafter, the present disclosure provides a specific adjusting system that implements the above adjusting method.

As shown inFIG. 1, a constant amplitude adjusting system for pressure pulse of drilling tool, comprising:

a pressure pulse generator1that is arranged in a drill collar2for generating a pressure pulse wave, where the opening degree of the pressure pulse generator is adjustable;

a flow measuring apparatus3that is located at the rear of the pressure pulse generator1and is also arranged in the drill collar2; the front and rear described in this embodiment are defined with respect to the drill collar2, where the end with a drill bit of the drill collar2is the front, and the other end is the rear; the flow measuring apparatus3is used to measure a current flow velocity value of the mud at the rear of the pressure pulse generator1; and

a controller4that is arranged on an outer sidewall of the drill collar2for receiving the current flow velocity value measured by the flow measuring apparatus3, and comparing the current flow velocity value with a preset flow velocity value, and sending an opening degree adjustment instruction to the pressure pulse generator1.

When the mud inside the drill collar2flows through the flow measuring apparatus3, the flow measuring apparatus3measures the current flow velocity value of the mud and sends the current flow velocity value to the controller4, and the controller4compares the obtained current flow velocity value with the preset flow velocity value. When the current flow velocity value is equal to the preset flow velocity value, the pressure pulse generator1does not need to be adjusted; when the current flow rate value is less than the preset flow rate value, the controller sends an instruction of increasing the opening degree to the pressure pulse generator1to cause the pressure pulse generator1to increase the opening degree; and when the current flow velocity value is greater than the preset flow velocity value, the controller sends an instruction of decreasing the opening degree to the pressure pulse generator1to cause the pressure pulse generator1to decrease the opening degree. The mud flow velocity in the drill collar2is equal to the preset value by adjusting the opening degree of the pressure pulse generator1, and when the mud flow velocity in the drill collar2is equal, the flow velocity of the mud which flows through the pressure pulse generator1is stable, and the pressure pulse wave generated by the pressure pulse generator1is of constant amplitude.

Specifically, the flow measuring apparatus3comprises an impeller5and a first angle sensor6, and the first angle sensor6is installed in the impeller5. When the mud flows through the impeller5, the mud drives the impeller5to rotate, and the impeller5in turn drives the first angle sensor6to rotate. The first angle sensor6measures the rotational speed of the impeller5, and the controller4converts the rotational speed information into the current mud flow velocity.

Since both the controller4and the pressure pulse generator1of the present disclosure require electricity, if the battery is separately provided, there is a problem that the battery needs to be replaced, and if the power is supplied from a power supply lead, special treatment is required for the structure of the drill collar2, which will increase the difficulty of manufacture. Therefore, to solve the problem of power supply, an embodiment also provides a generator assembly7, which is arranged inside the drill collar2. The generator assembly7is electrically connected to the controller4, and the controller4is electrically connected to the pressure pulse sensor1. A rotor8of the generator assembly7is fixedly connected to the impeller5. While the impeller5is rotating, the rotor8of the generator assembly7is driven to rotate, thereby causing the generator assembly7to generate electricity. This effectively reduces the manufacturing difficulty of the drill collar2and also solves the problem of power supply.

The pressure pulse generator1is a central component of the present disclosure, which can take a variety of structural forms, and the present disclosure introduces two preferred solutions:

solution 1: As shown inFIG. 1andFIG. 3, the pressure pulse generator1comprises a motor9, a valve seat10, a valve core11, a screw rod12and a mounting sleeve13, wherein the drill collar2has a motor mounting cavity14with cylindrical structure, the motor mounting cavity14is arranged along an axial direction of the drill collar2, a flow channel is formed between the outer wall of the motor mounting cavity14and the inner wall of the drill collar2, and the mud flowing through the pressure pulse generator1flows through the flow channel to the rear of the drill collar2. The motor9is mounted in the motor mounting cavity14, the motor9is electrically connected to the controller4, and the screw rod12is fixedly mounted on a rotating shaft15of the motor9by a coupling42. The central position of the mounting sleeve13has an internally threaded hole, the mounting sleeve13is screwed with the screw rod12, and the valve core11is fixedly connected with the mounting sleeve13. The valve seat10is fixed in the drill collar2, the center of the valve seat10has a through hole through which the mud flows. The drill collar2is provided with a mounting seat16, and the mounting sleeve13is inserted into the mounting seat16and is movable along the axial direction of the mounting seat16. The mounting seat16is also used to limit the degree of freedom in the circumferential direction of the mounting sleeve13. The mounting seat16is provided with a guide groove43arranged along the axial direction, and the outer wall of the mounting sleeve13is provided with a guide rail44arranged along its length direction. The degree of freedom in the circumferential direction of the mounting sleeve13is limited by the cooperation of the guide rail44and the guide groove43, that is, the mounting sleeve13cannot rotate relative to the mounting seat16. This is only one way of limiting the degree of freedom in the circumferential direction. It can also be realized in other ways, for example, the profile of the mounting sleeve13is polygonal, and the mounting seat16has a polygonal hole that fits with the mounting seat13. A second angle sensor19is mounted at a rear end of the rotating shaft15.

Operation principles: when the motor9receives the adjustment instruction from the controller4, it starts to operate. When the rotating shaft15rotates, the screw rod12is driven to rotate, and the screw rod12drives the mounting sleeve13to move in the axial direction, thereby changing the position of the valve core11. When the position of the valve core11relative to the valve seat10is changed, the flowable area of the through hole in the valve seat10is changed, thereby realizing adjustment of the opening degree. The position of the valve core11can be precisely controlled by providing the screw rod12and the second angle sensor19. The rotation angle and the number of rotations of the rotating shaft15can be measured by the second angle sensor19. Since the pitch on the screw rod12is fixed, the displacement of the valve core11is fixed when the rotating shaft15makes one rotation, thereby realizing the precise adjustment of the valve core11.

Solution 2: as shown inFIG. 4, the pressure pulse generator1comprises a motor9, a valve seat10and an adjusting plate17, wherein the drill collar2has a cylindrical motor mounting cavity14, and the motor9is mounted in the motor mounting cavity14, the motor9is electrically connected to the controller4. The valve seat10is fixed in the drill collar2, and the adjusting plate17is fixedly mounted onto a rotating shaft15of the motor9, and the valve seat10and the adjusting plate17are respectively provided with a through hole18. A second angle sensor19is mounted at the rear end of the rotating shaft15(the second angle sensor19is not shown inFIG. 4, andFIG. 1of the solution 1 can be referred to).

Operation principle: after receiving the adjustment instruction from the controller4, the motor9rotates the corresponding angle according to the instruction. As the rotating shaft15rotates, the adjusting plate17mounted at the end thereof also rotates. As the adjusting plate17rotates, the overlapping area between the through hole18in the adjusting plate17and the through hole18in the valve seat10changes, thereby realizing the adjustment of the opening degree. The solution has the advantages of precise adjustment and simple structure.

In order to improve the adjustment accuracy of the present disclosure, a fine adjustment apparatus is also provided. Referring toFIGS. 1 and 2, a pressure measuring mechanism20is further provided. The pressure measuring mechanism20is provided on the outer sidewall of the drill collar2. The pressure measuring mechanism20includes a sensor assembly21and a sealing member22. A mounting groove23is formed in the outer sidewall of the drill collar2, and the sealing member22is fastened to the mounting groove23and fixed by bolts. The sensor assembly21is fixedly mounted in the mounting groove23, a liquid inlet hole24communicatively connected with the center flow channel31of the drill collar2is provided in the mounting groove23, and a liquid inlet end of the sensor assembly21is communicatively connected with the liquid inlet hole24. The sensor assembly21is electrically connected to the controller4.

After the preliminary adjustment of the pressure pulse generator1is completed, it needs to be fine adjusted. If the adjustment of the pressure pulse generator1meets the requirements, the mud pressure in the drill collar2should be equal to the preset pressure value, if not, the pressure pulse generator1needs to be fine adjusted. The mud enters the liquid inlet hole24through the center flow channel31and flows into a pressure measuring end of the sensor assembly21. When the sensor assembly21detects the current pressure value of the mud and transmits the current pressure value to the controller4, the controller4determines how to further adjust the pressure pulse generator1. It should be noted that the sensor assembly21can adopt either a wired sensor or a wireless sensor. To ensure the accuracy of data transmission, the embodiment preferably uses the wired sensor.

As shown inFIGS. 5 and 6, preferably, the mounting groove23comprises a first groove body25and a second groove body26which are radially arranged along the drill collar2, and the second groove body26is arranged on the bottom of the first groove body25. The sealing member22comprises a cover portion27and a limiting portion28formed as an integrated structure, the shape and size of the cover portion27are correspondingly identical to the shape and size of the first groove body25, and the shape and size of the limiting portion28are correspondingly identical to the shape and size of the second groove body26. A stepped hole29is formed in each of the two ends of the cover portion27, and threaded holes30corresponding to the stepped holes29are formed in the first groove body25. A seal ring45is provided on the outer wall of the limiting portion28. It should be noted that the shape of the first groove body25and the second groove body26need not be specifically limited, as long as the requirements for use can be met. In the embodiment, preferably, the first groove body25is a rectangular groove, and the second groove body26is a groove having a rectangular shape in the middle and a semicircular shape at both ends. The sealing ring45on the outer wall of the limiting portion28acts as a seal to prevent the mud outside the drill collar2from entering the second groove body26. Once the mud enters the second groove body26, the normal operation of the sensor assembly21is affected. The sealing ring45can also be arranged on the sidewall of the second groove body26. In order to improve the sealing effect, sealing rings can be simultaneously provided on the top surface of the first groove body25and on the bottom surface of the cover portion27.

In addition, the drill collar2is rotated at a high speed during operation, so that the top surface of the cover portion27preferably adopts a curved surface, that is, when the cover portion27is fixed, the cover portion27and the drill collar2constitute a complete cylindrical shape. Thus, during operation, the edge of the cover portion27is not washed by the mud, thereby protecting the sealing member22. The use of such a structure has the problem of inconvenient disassembly. For this reason, as shown inFIG. 6, the top of the cover portion27is provided with at least two disassembling holes46. In this embodiment, four disassembling holes46are preferably provided, the four corners of the cover portion27are respectively each provided with a disassembling hole46, and the disassembling hole46is a blind hole. The sealing member22can be easily disassembled by a tool by providing the disassembling hole46.

In order to ensure the normal operation of the sensor, it is necessary to prevent the liquid (mud) from entering the second groove body26, so it is very important to seal the second groove body26well. Specifically, referring toFIG. 5andFIG. 7, a lower holding groove32is arranged on the bottom of the second groove body26, an upper holding groove33is arranged on the bottom of the limiting portion28, and the upper holding groove33and the lower holding groove32are oppositely disposed. The sensor assembly21is mounted in a space formed by the upper holding groove33and the lower holding groove32, and one end of the liquid inlet hole24is located in the lower holding groove32, and the other end of the liquid inlet hole24is communicatively connected with the central flow channel31. Since the present disclosure uses the wired sensor assembly21, a wire harness hole41is further provided. One end of the wire harness hole41is located in the lower holding groove32, and the other end of the wire harness hole41is in communicative connection with a wire routing hole34of the drill collar2.

As shown inFIG. 2andFIG. 8, the sensor assembly21comprises a sheath35, a connector36and a sensor37, wherein a first mounting hole38is radially formed in a sidewall of one end of the sheath35, a second mounting hole39is axially formed in the other end of the sheath35, and the first mounting hole38and the second mounting hole39are communicatively connected through a flow channel40. One end of the connector36is fixedly mounted in the first mounting hole38, and the sensor37is fixedly mounted in the second mounting hole39. The sheath35is preferably made of an insulating waterproof material such that even if the liquid accidentally enters the second groove body26, the sheath35will protect the sensor37from short circuit and enable the sensor37to operate normally. Preferably, both ends of the connector36are provided with sealing rings to prevent liquid leakage from the connector36.

Since the liquid (mud) is in contact with a sensing end of the sensor37, the sensing end of the sensor37and the sheath35should be installed in a sealed manner. To prevent the sensor37from swinging, preferably, the inner wall of an opening end of the second mounting hole39is provided with a circular groove49in which a limiting circlip50is mounted. The sensor37can be fixed by the limiting circlip50. Further preferably, the outer wall of the sensor37is provided with a limiting hole. A through hole51is formed in the sheath35. After the sensor37is installed in the second mounting hole39, the limiting hole is opposite to the through hole51. A limiting pin52matched with the limiting hole is mounted in the through hole51. The sensor37can be further positioned by the limiting pin52, so that axial movement of the sensor37is prevented.

Since sealing is critical, the mud should be prevented from leaking from a joint between the connector36and the liquid inlet hole24, in addition to preventing the mud from leaking from the inside of the sensor assembly. As shown inFIG. 5andFIG. 7, a first locating hole48is formed in the upper holding groove33, and a second locating hole47is formed in the lower holding groove32. A first locating pin matched with the first locating hole48and a second locating pin matched with the second locating hole47are arranged on the sensor assembly21.

The sensor assembly21can be effectively positioned through the first locating hole48, the second locating hole47, the first locating pin and the second locating pin, thereby ensuring the sealing effect at the joint of the connector36and preventing leakage.

The structures, features and effects of the present disclosure are described in detail in the above embodiments with reference to the drawings, but they only show the preferred embodiments of the present disclosure, and the drawings shall not define the embodying scope of the present disclosure. The variations made according to the concept of the present disclosure, or the equivalent embodiments including equivalent modifications within the scope of the description and the drawings shall fall into the protection scope of the present disclosure.