A position sensor and actuator

Abstract

The application provides a position sensor and actuator, which comprises a shell, a cavity with an open end is arranged in the shell, the cavity is suitable for being communicated with oil; a pull rod is arranged in the cavity, a brush is arranged on the pull rod, the pull rod has a first movement state of moving away from the cavity under the action of external force and a second movement state of moving towards the inside of the cavity; a resistor is arranged in the shell and abuts against the brush; a lead-out end is arranged on the shell and is in communication with the brush and the resistor. The lead-out end is in communication with the brush and the resistor, which is convenient for connecting an external power supply and applying voltage on the resistor. In the movement process of the brush on the resistor, the position of the brush can be effectively detected by detecting the voltage feedback of the resistor, the brush is arranged on the pull rod, and then the position of the pull rod can be detected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensor, in particular to a position sensor and actuator. BACKGROUND

[0002] At present, the position sensor used in the high pressure environment, such as the device inside the hydraulic cylinder, mainly includes magnetostrictive displacement sensor and LVDT (linear variable differential transformer) two kinds.

[0003] Among them, the magnetostrictive displacement sensor mainly includes a measuring inductive element and a movable magnetic ring, which can detect the position of the movable magnetic ring through the non-contact measuring inductive element, and then measure the actual displacement value of the detected product, but the hysteresis effect caused by the magnetostrictive material in the measuring inductive element will further produce displacement hysteresis phenomenon, and then cause the magnetostrictive displacement sensor to produce larger error, affect the measurement accuracy of the sensor; and the LVDT usually includes a primary coil, two secondary coils, a core and a coil skeleton, and a shell and other components, in the working process of the LVDT, the movement of the core cannot exceed the linear range of the coil, otherwise the nonlinear value will be generated, therefore all the LVDT has a linear range, in the actual use process, in order to obtain excellent linear performance, the shell of the LVDT sensor is longer than the stroke, therefore, the effective stroke is relatively small compared with the overall length, which affects its application in the closed high pressure environment, such as the internal environment of the hydraulic cylinder. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defects of large error and short effective stroke of the sensor used in the high pressure hydraulic environment in the prior art, so as to provide a position sensor and actuator.

[0005] The present application provides a position sensor, comprising: a shell, an open cavity is arranged in the shell, the cavity is suitable for entering oil; a pull rod, one end of the pull rod is arranged in the cavity, an electric brush is arranged on the pull rod, the pull rod has a first movement state of moving away from the cavity under the action of external force and a second movement state of moving towards the inside of the cavity; a resistor body, which is nested in the shell and abuts against the electric brush; a lead-out end, which is arranged on the shell and is in communication with the electric brush and the resistor body.

[0006] The lead-out end comprises: a base, which is arranged at one end of the shell away from the opening and has a wiring hole arranged thereon; a wiring terminal, which is electrically connected with the electric brush and the resistor body and corresponds to pass through the wiring hole; a sealing layer, which is arranged between the wiring hole and the wiring terminal and is suitable for sealing the connection between the wiring terminal and the wiring hole.

[0007] The base and the terminal are made of metal, and the sealing layer is made of glass and is sintered in the terminal hole.

[0008] The position sensor further comprises an oil hole arranged on the shell and communicating with the cavity, and adapted to introduce oil into the cavity.

[0009] The shell is provided with at least two oil holes, which are respectively arranged at one end adjacent to the opening and at one end adjacent to the base.

[0010] The position sensor further comprises an electric conductor layer arranged between the shell and the electric resistance body and connected with the lead-out end.

[0011] The actuator comprises the position sensor, a first housing comprising a first inner cavity provided with a first opening, the position sensor being limited in the first inner cavity, the first opening being arranged in the same direction as the opening of the position sensor, an extension member comprising at least a first sleeve, the first sleeve being arranged between the first housing and the shell, a limiting member and a first extension end being arranged on the first sleeve, the limiting member being limitedly connected with one end of the pull rod away from the cavity, the first extension end being arranged apart from the limiting member and being adapted to drive the pull rod to switch between the first movement state and the second movement state under the action of an external force.

[0012] The actuator further comprises a first oil port arranged on the first housing and communicating with the cavity in the shell and adapted to introduce oil into the cavity.

[0013] The actuator further comprises a guide cylinder arranged between the first housing and the shell and limitedly connected with the first housing, a first oil channel being arranged on the inner side of the guide cylinder, the first oil channel communicating with the first oil port and the oil hole.

[0014] A first limiting portion is arranged on the inner wall of the first housing.

[0015] A second limiting portion is arranged on one end of the first sleeve away from the first opening, the second limiting portion being adapted to limit the first limiting portion to move out of the first inner cavity.

[0016] The actuator further comprises a second oil port arranged on the inner wall of the first inner cavity and adjacent to the first limiting portion, the second limiting portion abutting against the inner wall of the first inner cavity, a second oil channel being arranged between the first housing and the shell, the second oil channel communicating with the second oil port and having two ends corresponding to the first limiting portion and the second limiting portion.

[0017] The technical scheme of the present application has the following advantages:

[0018] 1. The position sensor provided by the present application comprises: a shell, an open cavity is arranged in the shell, the cavity is suitable for being connected to oil; a pull rod, one end of the pull rod is arranged in the cavity, a brush is arranged on the pull rod, the pull rod has a first movement state of moving away from the cavity under the action of an external force and a second movement state of moving towards the inside of the cavity; a resistor, the resistor is arranged in the shell in a nested manner and abuts against the brush; and a lead-out end, the lead-out end is arranged on the shell and is in communication with the brush and the resistor.

[0019] By arranging the lead-out end in communication with the brush and the resistor, the external power supply can be connected, the voltage is applied to the resistor, and the position of the brush can be effectively detected by detecting the voltage feedback of the resistor during the movement of the brush on the resistor. The brush is arranged on the pull rod, and thus the position of the pull rod can be measured. In addition, the cavity in which the pull rod moves is provided with an opening and is connected to oil. On the one hand, the internal and external pressures are balanced, so that the sensor can adapt to the super-high liquid pressure environment. On the other hand, the open arrangement connected to oil can be lubricated by oil to avoid sliding wear and meet the electrical performance and insulation requirements of the structure in the cavity.

[0020] In this way, the magnetostrictive material does not need to be arranged, the displacement hysteresis caused by the magnetic hysteresis does not exist, and the adverse effects of residual magnetism and excitation current fluctuation on displacement measurement do not exist. Therefore, the accuracy of the sensor can be greatly improved, and the error can be reduced. In addition, the arrangement does not need to be limited by the structure of the bidirectional coil. The moving stroke of the brush on the resistor is the effective stroke of the pull rod during measurement. Since the resistor is arranged in the shell in a nested manner, the length of the resistor can be extended according to the length of the shell. Therefore, the effective stroke of the pull rod is reduced, and the measurement stroke of the sensor is improved. Therefore, the arrangement effectively overcomes the problems of large error and short effective stroke of the sensor used in the high-pressure hydraulic environment in the prior art.

[0021] 2. The position sensor provided by the present application, the base and the terminal are made of metal, and the sealing layer is made of glass and is sintered in the terminal hole.

[0022] In a high liquid pressure environment, the position sensor cable lead-out position is subjected to a large pressure and is prone to sealing problems. In the prior art, the lead-out wire of the cable is usually made of a plastic insulating sheath. The adhesion between the glue and the sheath is not strong, the adhesion edge is prone to gaps, and the traditional glue sealing is difficult.

[0023] By arranging the base and the terminal made of metal, the structural strength can be improved, and the combination with the sealing layer is also improved. In addition, the sealing layer made of glass can be sintered in the terminal hole and tightly combined with the terminal, and the pressure resistance of the position of the terminal hole is further improved.

[0024] 3. The position sensor provided by the present application, at least two oil holes are arranged on the shell, and are respectively arranged at one end adjacent to the opening of the shell and at one end adjacent to the base.

[0025] By arranging the oil holes, oil can be introduced into the cavity to meet the requirements of pressure balance, lubrication and insulation, avoid contact and wear between the pull rod and the resistor or the shell when using sliding sealing mode, improve the service life, and reduce the required external force during the starting process. At the same time, the arrangement of the oil holes, combined with the opening arranged on the cavity, makes it more convenient for oil to flow into the cavity.

[0026] In addition, the arrangement of at least two oil holes can effectively control the introduction or outflow of oil at the front and rear positions during the movement of the pull rod, ensure the sufficiency of oil, and reduce the pulsation effect during the movement of the pull rod and the oil pressure during the assembly process.

[0027] 4. The actuator provided by the present application, comprising the position sensor described above; a first housing comprising a first inner cavity provided with a first opening, the position sensor being limited in the first inner cavity, and the first opening being arranged in the same direction as the opening on the position sensor; an extension member comprising at least a first sleeve, the first sleeve being nested between the first housing and the shell, and being provided with a limiting member and a first extension end, the limiting member being in limiting connection with one end of the pull rod away from the cavity, and the first extension end being arranged in a spaced manner with the limiting member and being adapted to drive the pull rod to switch between the first movement state and the second movement state under the action of an external force.

[0028] By nesting the first housing, the extension member and the position sensor, the limiting member on the extension member is connected with the pull rod, the first extension end on the extension member moves under the action of an external force and drives the pull rod to move, and the spaced arrangement of the first extension end and the limiting member can further improve the movement stroke of the first extension end. At the same time, the nested arrangement of the first housing, the extension member and the position sensor can drive the shell, the resistor and the lead-out end of the position sensor to move relative to the extension member and the pull rod when the first housing is driven by an external force, so as to realize single-out-rod symmetrical output. Compared with the double-out-rod symmetrical hydraulic cylinder in the prior art, the axial length is further shortened, and the effective stroke of the sensor is effectively prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any inventive labor.

[0030] Figure 1 Structure diagram of a position sensor provided in an embodiment of the present application;

[0031] Figure 2 Structure diagram of a position sensor provided in an embodiment of the present application; Figure 1 Structure diagram of a position sensor provided in an embodiment of the present application;

[0032] Figure 3 Structure diagram of an actuator provided in an embodiment of the present application;

[0033] Explanation of reference numerals:

[0034] 1, housing; 11, cavity; 12, oil hole; 2, pull rod; 21, brush piece; 3, resistance body; 4, lead-out end; 41, base; 411, wiring hole; 42, wiring terminal; 43, sealing layer; 5, electric conductor layer; 6, first shell; 61, first inner cavity; 62, first oil port; 63, first limiting part; 64, second oil port; 65, second oil path; 7, first sleeve; 71, limiting piece; 72, first extension end; 73, second limiting part; 8, guide cylinder; 81, first oil path. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] In the description of the present application, it should be noted that the terms “center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”, “inner”, “outer” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms “first”, “second”, “third” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] like Figure 1 - Figure 3 As shown, this embodiment provides a position sensor, including: a housing 1, a pull rod 2, a resistor 3, and a lead-out terminal 4.

[0040] The housing 1 is cylindrical and has a cavity 11 with one end open. The cavity 11 is suitable for passing oil. One end of the pull rod 2 extends into the cavity 11. In this embodiment, a brush 21 is provided on the end of the pull rod 2. The outer diameter of the brush 21 is greater than or equal to that of the pull rod 2. Furthermore, a rod core can be sleeved in the middle of the pull rod 2. The rod core can be fixedly connected to the lead-out end 4 provided at the end of the housing 1 and is concentrically arranged with the housing 1, which can improve the linearity of the pull rod 2. In addition, an elastic element such as a spring can be provided on the brush 21. The other end of the pull rod 2 extends out of the housing 1 and has a first motion state of moving away from the cavity 11 under the action of external force and a second motion state of moving towards the inside of the cavity 11.

[0041] The resistor 3 is nested in the housing 1 in a sleeve shape and abuts against the brush 21. The specific material can be set as needed. In this embodiment, it can be conductive plastic. Furthermore, one end of the resistor 3 extends to the opening of the cavity 11, and the other end extends to the lead end 4. The lead end 4 is set on the end of the housing 1 away from the opening and is connected to the brush 21 and the resistor 3, specifically for electrical connection.

[0042] By setting the lead-out terminal 4 to be connected to the brush component 21 and the resistor 3 respectively, it is convenient to connect to an external power supply. When a voltage is applied to the resistor 3, the position of the brush can be effectively detected by detecting the voltage feedback of the resistor 3 during the movement of the brush. The brush component 21 is set on the pull rod 2, so the position of the pull rod 2 can be measured. At the same time, an opening is provided in the cavity 11 of the pull rod 2, and oil is introduced. On the one hand, the internal and external pressure is balanced, so that the sensor can adapt to the ultra-high liquid pressure environment. On the other hand, the open setting of introducing oil can be lubricated by oil to avoid sliding wear. At the same time, the oil also meets the electrical performance and insulation requirements of the internal structure of the cavity 11.

[0043] In this way, the displacement hysteresis caused by the magnetic hysteresis effect does not exist, and the adverse effects of the remanence and excitation current fluctuations on displacement measurement are eliminated, which can greatly improve the accuracy of the sensor and reduce errors. At the same time, this setting does not need to be limited by the structure of the bidirectional coil, and the moving stroke of the brush piece 21 on the resistance body 3 is the effective stroke of the pull rod 2 during the measurement. Since the resistance body 3 is nested in the shell 1, the length of the resistance body 3 can be extended according to the length of the shell 1, which reduces the limitation on the effective stroke of the pull rod 2 and improves the measurement stroke of the sensor. Therefore, this setting effectively overcomes the problems of large error and short effective stroke of the sensor used in the high-pressure hydraulic environment in the prior art.

[0044] The lead-out end 4 includes a base 41, a terminal 42, and a sealing layer 43. The base 41 is arranged at the end of the shell 1 away from the opening, and a terminal hole 411 is arranged on the base 41. The terminal 42 is electrically connected to the brush piece 21 and the resistance body 3, and corresponds to the terminal hole 411. The number and position of the terminal hole 411 can be adjusted as needed. The sealing layer 43 is arranged between the terminal hole 411 and the terminal 42, and seals the terminal 42 and the terminal hole 411. Preferably, the base 41 and the terminal 42 are made of metal, and the sealing layer 43 is made of glass and is sintered in the terminal hole 411. As a variable embodiment, the base 41 can be integrally formed with the shell 1. As another variable embodiment, the terminal 42, the base 41, and the shell 1 can be made of ceramic or other materials, and the sealing layer 43 can be made of insulating ceramic or other materials.

[0045] In a high liquid pressure environment, the position sensor cable lead-out place is under great pressure and is prone to sealing problems. In the prior art, the lead-out wire of the cable is usually a plastic insulating sheath, and the adhesion between the glue and the sheath is not strong, which is prone to slipping and the adhesive edge is prone to voids, making it difficult to seal with traditional glue.

[0046] By arranging the base 41 and the terminal 42 made of metal, the structural strength can be improved, and the combination with the sealing layer 43 is also improved. At the same time, the sealing layer 43 made of glass can be sintered in the terminal hole 411 and tightly combined with the terminal 42, further improving the pressure resistance at the position of the terminal hole 411. The position sensor further comprises an oil hole 12 arranged on the shell 1 and communicating with the cavity 11, and is adapted to introduce oil into the cavity 11.

[0047] By setting the oil hole 12, oil can be introduced into the cavity 11 to meet the balance pressure and lubrication and insulation requirements, avoiding contact and wear between the pull rod 2 and the resistance body 3 or the shell 1 when using sliding sealing, improving the service life and reducing the external force required during starting. At the same time, the setting of the oil hole 12, combined with the opening of the cavity 11, makes it easier for oil to flow into the cavity. As an alternative embodiment, the oil hole 12 can not be set, and only the opening is set as an open setting.

[0048] In this embodiment, two oil holes 12 are provided on the shell 1, and are respectively provided at one end adjacent to the opening of the shell 1 and at one end adjacent to the base 41. As an alternative embodiment, one or more oil holes 12 can be added to the shell 1. The setting of at least two oil holes 12 can effectively control the inflow and outflow of oil before and after movement during the movement of the pull rod 2, ensuring sufficient oil and reducing the pulsation effect during the movement of the pull rod 2 and the oil pressure during assembly.

[0049] The position sensor further comprises an electric conductor layer 5, which is nested between the shell 1 and the resistance body 3 and is connected with the lead-out end 4. As an alternative embodiment, the electric conductor layer 5 can not be provided.

[0050] The present embodiment also provides an actuator comprising the above-mentioned position sensor, first housing 6 and extension.

[0051] The first housing 6 is cylindrically arranged and comprises a first inner cavity 61 provided with a first opening, the first inner cavity 61 is limitedly connected with the lead-out end 4 of the position sensor through a limiting groove at the bottom of the cylinder, and the first opening is arranged in the same direction as the opening on the position sensor. The first housing 6 is further provided with an output rod on the outer wall of the end away from the first opening.

[0052] The extension comprises a first sleeve 7, one end of which is open and the other end is closed, the open end extends into the first inner cavity 61 and is nested between the first housing 6 and the shell 1, the other end is closed and extends through the first opening, and the first extension end 72 is provided at the other end, a limiting member 71 is provided inside the open end of the first sleeve 7, the limiting member 71 extends to the center along the first sleeve 7 in a sheet shape, and an O-shaped sealing ring is provided in the middle, which is nested and limited on the end of the pull rod 2 away from the cavity 11 and is limitedly connected therewith. The first extension end 72 and the limiting member 71 are spaced apart in the length direction of the pull rod 2 and are adapted to drive the pull rod 2 to switch between the first movement state and the second movement state under the action of external force. As an alternative embodiment, one or more sleeves can be provided between the first sleeve 7 and the position sensor, and between the first sleeve 7 and the first housing 6.

[0053] By nesting the first shell 6, the extension piece and the position sensor, the limiting piece 71 on the extension piece is connected with the pull rod 2, the first extension end 72 on the extension piece moves under the action of external force and drives the pull rod 2 to move, the interval arrangement of the first extension end 72 and the limiting piece 71 can further improve the movement stroke of the first extension end 72, and meanwhile, the nesting arrangement of the first shell 6, the extension piece and the position sensor can drive the first shell 6 and the shell 1, the resistance body 3 and the lead-out end 4 and other structures of the position sensor to move relative to the extension piece and the pull rod 2 when the first shell 6 is driven by external force, so that single-output rod symmetrical output is realized, the axial length is further shortened compared with the double-output rod symmetrical hydraulic cylinder in the prior art, and the effective stroke of the sensor is effectively lengthened.

[0054] The actuator further comprises a first oil port 62 arranged on the first shell 6 and in communication with part of the first inner cavity 61 and also in communication with the cavity 11 in the shell 1, which is suitable for introducing oil into the cavity 11. Specifically, the first oil port 62 is arranged on the side of the first shell 6 close to the output rod and is arranged perpendicular to the direction of the pull rod 2.

[0055] The actuator further comprises a guide cylinder 8 arranged between the first shell 6 and the shell 1 and in limiting connection with the first shell 6, and the inner side of the guide cylinder 8 is provided with a first oil channel 81 formed between the inner wall of the shell 1 and the guide cylinder 8, one end of which is in communication with the first oil port 62 and the other end is in communication with the open end of the first sleeve 7, and at the same time, is in communication with the two oil holes 12 and the opening on the shell 1, thereby providing oil for the position sensor.

[0056] The inner wall of the first shell 6 is provided with a first limiting portion 63, and the end of the first sleeve 7 away from the first opening is provided with a second limiting portion 73 suitable for limiting the first limiting portion 63 from coming out of the first inner cavity 61. In this embodiment, the first limiting portion 63 is an annular protrusion on the inner wall of the first shell 6 close to the first opening, and the second limiting portion 73 is an annular protrusion protrudingly arranged on the outer edge of the end of the open end of the first sleeve 7, respectively towards the inner wall of the first shell 6 and the shell 1 of the position sensor. As an alternative embodiment, the first limiting portion 63 and the second limiting portion 73 can also be a clamping groove and a clamping block or two barbs, respectively

[0057] The actuator further comprises a second oil port 64 arranged on the inner wall of the first inner cavity 61 and adjacent to the first limiting portion 63, and the second limiting portion 73 is in abutment with the inner wall of the first inner cavity 61, and the second oil channel 65 is arranged between the first shell 6 and the shell 1, in communication with the second oil port 64 and arranged at both ends corresponding to the first limiting portion 63 and the second limiting portion 73.

[0058] In the present embodiment, the first inner cavity 61 has an inner diameter d3, the first sleeve 7 has an inner diameter d1 and an outer diameter d2 at the open end, and d1 2 =d3 2 -d2 2 .

[0059] Obviously, the above embodiment is only an example for clearly illustrating the present application, and is not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A position sensor, characterized by The utility model relates to a position sensor, including: The shell (1) is provided with the cavity (11) in one end opening, and the cavity (11) is suitable for going into oil liquid; Pull rod (2) one end pull rod (2) stretches in the cavity (11), is provided with the brush piece (21) on it, and pull rod (2) has the first movement state under the action of external force and the second movement state of moving towards the inside of the cavity (11) away from the cavity (11) movement; Resistance body (3) is nested in the shell (1), and is in contact with the brush piece (21); Lead-out end (4) is provided on the shell (1), and is in communication with the brush piece (21) and the resistance body (3) setting;Lead-out end (4) includes base (41), terminal (42) and sealing layer (43);Base (41) is provided on the one end of shell (1) away from the opening, and is provided with terminal hole (411) on it;Terminal (42) is electrically connected with the brush piece (21) and the resistance body (3), and corresponds to pass through the terminal hole (411);Sealing layer (43) is provided between the terminal hole (411) and the terminal (42), and is suitable for sealing connection terminal (42) and terminal hole (411);The base (41) and the terminal (42) are provided with metal material, and the sealing layer (43) is provided with glass material, and is suitable for sintering in the terminal hole (411); Oil hole (12) is provided on the shell (1), and is in communication with the cavity (11), and is suitable for going into oil liquid in the cavity (11);The shell (1) is provided with at least two oil holes (12), and is respectively provided on the one end of the shell (1) adjacent to the opening and the one end adjacent to the base (41).

2. The position sensor of claim 1, wherein, Further including: Electric conductor layer (5) is nested between the shell (1) and the resistance body (3), and is connected with the lead-out end (4) setting.

3. An actuator characterized by comprising: Including: The position sensor of claim 1 or 2; First shell (6) includes first inner cavity (61) provided with first opening, and the position sensor is limited in the first inner cavity (61), and the first opening is arranged in the same direction with the opening on the position sensor, and the first limiting portion (63) is arranged on the inner wall of the first shell (6); The extension piece at least includes a first sleeve (7), the first sleeve (7) is nested between the first shell (6) and the shell (1), and the limiting piece (71) and the first extension end (72) are arranged on the first sleeve (7), the limiting piece (71) is limitedly connected with the one end of the pull rod (2) away from the cavity (11), the first extension end (72) is arranged at intervals with the limiting piece (71), and is suitable for driving the pull rod (2) to convert between the first movement state and the second movement state under the action of external force, the second limiting portion (73) is arranged on the one end of the first sleeve (7) away from the first opening, and the second limiting portion (73) is suitable for limiting the first limiting portion (63) to get out of the first inner cavity (61). A second oil port (64) is arranged on the inner wall of the first inner cavity (61) and is arranged adjacent to the first limiting portion (63). The second limiting portion (73) is in abutment with the inner wall of the first inner cavity (61). The first outer shell (6) and the shell (1) are clamped with a second oil path (65). The second oil path (65) is in communication with the second oil port (64) and is arranged at both ends corresponding to the first limiting portion (63) and the second limiting portion (73).

4. The actuator of claim 3, wherein Also includes: A first oil port (62) is arranged on the first outer shell (6) and is in communication with the cavity (11) in the shell (1). It is suitable for introducing oil into the cavity (11).

5. The actuator of claim 4, wherein Also includes: A guide cylinder (8) is arranged between the first outer shell (6) and the shell (1) and is in limiting connection with the first outer shell (6). The guide cylinder (8) is provided with a first oil path (81) on the inner side. The first oil path (81) is in communication with the first oil port (62) and the oil hole (12), respectively.

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