JP2013137087A - Actuator, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator allowing easy assembling of a fixing element without a play, and to provide a method for manufacturing the actuator.SOLUTION: A plurality of recesses 55 are formed at substantially the same axial direction positions on an outer peripheral surface of a nut 3 of this actuator. In an output shaft 30, a through-hole 57 which continues the recesses 55 and passes through the output shaft 30 in a radial direction is formed. A space 59 into which a fixing element 51 is fitted is constituted of the continuous recess 55 and through-hole 57. The fixing element 51 is fitted into each space 59 to engage and connect the nut 3 and the output shaft 30. A communication hole 70 is opened in an axial direction end face exposed to the outside of the output shaft 30 out of both axial direction end faces of the nut 3 and is provided to extend in the axial direction to be communicated with the space 59. A pressing pin 71 for pressing the fixing element 51 in the axial direction is pressed and fitted in the communication hole 70 to fix the fixing element 51 without a play.

Description

  The present invention relates to an actuator and a manufacturing method thereof.

  2. Description of the Related Art Conventionally, a ball screw type direct acting actuator has been widely used as a power conversion device that obtains a large axial output from a relatively small input torque by using a ball screw that converts rotational motion into linear motion. When a relatively small input torque from a drive source such as an electric motor is input to a screw shaft (or nut) constituting a ball screw via a speed reduction mechanism, the screw shaft (or nut) is rotated in a desired direction. The rotational motion of the screw shaft (or nut) is converted into linear motion of the nut (or screw shaft) screwed with the screw shaft (or nut) via a plurality of balls. Then, the linear motion of the nut (or screw shaft) is taken out from the output shaft connected to the nut (or directly from the screw shaft).

  There are various methods for connecting the nut and the output shaft. However, Patent Document 1 discloses a screw connection between a female screw formed on the inner peripheral surface of one end of the nut in the axial direction and a male screw formed on the outer peripheral surface of the output shaft. Discloses a ball screw type direct acting actuator in which a nut and an output shaft are connected. When such a connection method is adopted, it is possible to provide a nut support member that supports the nut on the other end in the axial direction of the nut in a cylindrical casing that includes the nut and the output shaft.

As a result, since the axial distance between the output shaft support member that supports the output shaft on the casing and the nut support member, that is, the distance between the support points can be increased, the radial load acting on the output shaft support member is reduced. It is possible to design an actuator with reduced stroke and a large stroke amount.
However, when the nut and the output shaft are screwed together, it is necessary to separately provide a centering mechanism such as an inlay in order to align the nut and the output shaft. When the misalignment between both shaft centers is large, the radial load acting on the output shaft support member becomes large, which may reduce the life of the output shaft support member.

If the nut and the output shaft are screwed together, it is difficult to determine the phase between the nut and the output shaft, so a phase determining mechanism must be provided separately. In addition, there is a problem that it is necessary to separately control the fastening torque of both screws and, depending on circumstances, it is necessary to separately provide a mechanism for preventing the separation of both screws from the viewpoint of safety design.
As a method of connecting the nut and the output shaft without causing such a problem, there is a technique using a cotter. This cotter is also used as an axial force transmission member, but may also be used as an axial positioning member. For example, Patent Document 2 discloses a technique in which an output rotating body is attached while being positioned at a predetermined axial position on a transmission output shaft by using a cotter.

  That is, a pair of cotters divided and formed in a semicircular shape is attached to an annular locking groove formed on the outer peripheral surface of the transmission output shaft with its inner peripheral portion inserted. These cotters are fixed to the outer peripheral surface of the transmission output shaft by a retainer ring and a circlip. The output rotator is mounted while being positioned on the transmission output shaft by being sandwiched between these cotters and a restricting portion protruding in a flange shape on the outer peripheral surface of the transmission output shaft.

JP 2000-161461 A Japanese Patent No. 4374265

  When assembling the cotter in such an actuator, it is preferable that the cotter is attached with a certain gap with respect to its attachment position from the viewpoint of assembling performance and dimensional error. That is, when a plurality of cotters are attached to the attachment position with a negative gap, assembly may be difficult due to a dimensional error, or scouring may easily occur in the ball screw portion after assembly.

However, if the cotter is installed with a gap, rattling occurs between the cotter and nut, between the cotter and the output shaft, and the responsiveness is impaired, or vibration causes a gap between the cotter and nut or between the cotter and output shaft. There is a possibility that fretting occurs and the play is further increased due to wear.
Therefore, an object of the present invention is to solve the above-described problems of the prior art and to provide an actuator with good response.

In order to solve the above problems, the present invention has the following configuration. That is, the actuator according to the present invention is an actuator that converts a rotational motion into a linear motion, and is arranged coaxially in a substantially cylindrical or substantially rectangular tube-shaped housing member and an inner space of the housing member, and receives rotational force. A screw shaft, a nut engaged with the screw shaft so as to linearly move along the screw shaft as the screw shaft is rotated by the rotational force, and a nut coupled to the nut. A hollow output shaft that linearly moves to output axial force, and an output shaft that is interposed between the outer peripheral surface of the output shaft and the inner peripheral surface of the housing member, and supports the output shaft on the housing member And a support member and satisfy the following four conditions A, B, C, and D.
Condition A: The nut is enclosed in the hollow interior of the output shaft.
Condition B: A space is formed that includes a recess formed in the outer peripheral surface of the nut and a through hole that is continuous with the recess and penetrates the output shaft in the radial direction, and a fixing element is provided in the space. The nut and the output shaft are engaged and connected by the fixing element.
Condition C: A communication hole that opens to an axial end surface exposed to the outside of the output shaft among both axial end surfaces of the nut and communicates with the space is provided for the space.
Condition D: A pressing pin that presses the fixing element in the axial direction is press-fitted into the communication hole.

  Moreover, when manufacturing the actuator which concerns on this invention, you may confirm the presence or absence of the said fixing element by inserting the said pressing pin in the said communicating hole.

According to the actuator of the present invention, a communication hole that opens to the axial end surface exposed to the outside of the output shaft among the both axial end surfaces of the nut and communicates with the space is provided, and the fixing element is pivoted in the communication hole. Since the pressing pin that presses in the direction is press-fitted and fitted, assembly is simple and play can be prevented. As a result, an actuator with good responsiveness can be provided.

It is sectional drawing which shows the structure of the actuator of 1st embodiment. It is sectional drawing of an output shaft unit. It is a perspective view which shows the output shaft unit in the state to which the fixing element was attached (illustration of the output shaft is abbreviate | omitted). It is a front view of a fixing element. It is a perspective view of the output shaft unit explaining the method of confirming the presence or absence of a fixed element.

Embodiments of an actuator and a manufacturing method thereof according to the present invention will be described in detail with reference to the drawings. In all the drawings, the same or corresponding parts are denoted by the same reference numerals.
[First embodiment]
FIG. 1 is a cross-sectional view (a cross-sectional view cut along a plane along the axial direction) showing the structure of the actuator of the first embodiment. 2 is a cross-sectional view showing the output shaft unit of the actuator shown in FIG. 1 (a cross-sectional view taken along a plane along the axial direction), and FIG. 3 shows the output shaft unit with a fixed element attached thereto. FIG. However, the output shaft is not shown in FIG.

The actuator of this embodiment uses a ball screw that converts rotational motion into linear motion, thereby converting a rotational force input from a drive source such as an electric motor into an axial force (axial force) and outputting the ball. It is a screw type direct acting actuator. In the present invention, “axial direction”, “radial direction”, and “circumferential direction” mean the axial direction, radial direction, and circumferential direction of the nut.
The actuator of this embodiment includes a ball screw 10 that converts rotational motion into linear motion, and a rotational force transmission unit 20 that receives rotational force from a drive source such as an electric motor (not shown) and transmits the rotational force to the screw shaft 1 of the ball screw 10. An output shaft 30 connected to the nut 3 of the ball screw 10 and outputting the axial force converted from the rotational force by the ball screw 10, and a substantially cylindrical shape (substantially rectangular tube shape) containing the ball screw 10 and the output shaft 30. The housing member 40 may be provided. In addition, what consists of the ball screw 10 and the output shaft 30 is called an output shaft unit.

  The ball screw 10 includes a screw shaft 1 having a helical screw groove 1a on the outer peripheral surface, a nut 3 having a helical screw groove 3a facing the screw groove 1a of the screw shaft 1 on the inner peripheral surface, and both screws. A plurality of balls (not shown) that are slidably loaded in a spiral ball rolling path formed by the grooves 1a and 3a, and the balls are circulated back from the end point of the ball rolling path to the starting point. A ball circulation path (see FIG. 3).

That is, the ball moves around the screw shaft 1 while moving in the ball rolling path to reach the end point of the ball rolling path, where the ball is scooped up from the ball rolling path to reach the ball circulation path. Enter one end. The ball that has entered the ball circulation path passes through the ball circulation path, reaches the other end of the ball circulation path, and then returns to the starting point of the ball rolling path.
In addition, the material of the screw shaft 1, the nut 3, and the ball is not particularly limited, and general materials can be used, and examples thereof include metals such as steel and ceramics. Further, the cross-sectional shape of the thread grooves 1a, 3a may be an arc shape or a gothic arc shape.

  When such a ball screw 10 relatively rotates the nut 3 and the screw shaft 1 screwed to the screw shaft 1 through the ball, the screw shaft 1 and the nut 3 are moved through the rolling of the ball. And move relative to each other in the axial direction. An endless ball path is formed by the ball rolling path and the ball circulation path so that the ball rolling in the ball rolling path circulates infinitely in the endless ball path. Therefore, the screw shaft 1 and the nut 3 can continuously move relative to each other. The ball circulation path is preferably formed integrally with the nut.

  The ball screw 10 and the output shaft 30 connected to the nut 3 of the ball screw 10 are contained in the internal space of the housing member 40, and the screw shaft 1 and the output shaft 30 of the ball screw 10 are the housing. It is arranged coaxially with the member 40. The nut 3 is included in one axial end portion (left end opening in FIG. 1) of the hollow interior 30a of the output shaft 30, and is connected to the output shaft 30 by a fixing element 51 (for example, a cotter).

  Below, the connection means of the nut 3 and the output shaft 30 is demonstrated. A plurality of rectangular parallelepiped recesses 55 are formed at substantially the same position in the axial direction of the outer peripheral surface of the nut 3, and the longitudinal direction thereof is formed along the circumferential direction of the nut 3. Further, the output shaft 30 is formed with a through-hole 57 having a rectangular cross section that is continuous with the recess 55 and penetrates the output shaft 30 in the radial direction, and the fixing element 51 includes the continuous recess 55 and the through-hole 57. A space 59 into which the fixing element 51 is fitted is formed.

The fixing element 51 has a substantially rectangular parallelepiped shape substantially the same shape as the space 59 (as shown in FIG. 4, the surface 51 a facing outward in the radial direction may be a curved surface along the outer peripheral surface of the nut 3). Therefore, the fixing element 51 is fitted in each space 59. At this time, both axial end surfaces of the fixing element 51 are in contact with the nut 3 and the output shaft 30 (that is, in contact with the inner wall surface of the space 59). The number of the fixing elements 51 and the spaces 59 is not particularly limited, but is two in the example of FIGS. 1 to 3, and the two fixing elements 51 and the spaces 59 are in the circumferential direction at a phase of 180 °. Is arranged. Of course, the number may be one, or three or four, but in the case of a plurality, it is preferable to arrange them equally in the circumferential direction.
With such a configuration, the nut 3 and the output shaft 30 are engaged and connected. Moreover, since the fixing element 51 can transmit only the axial force of the nut 3 to the output shaft 30 via both axial end surfaces thereof, it also functions as an axial force transmitting element.

  In addition, a plurality (two in this embodiment) of output shaft support members that support the output shaft 30 on the housing member 40 are spaced apart in the axial direction from the outer peripheral surface of the output shaft 30 and the inner periphery of the housing member 40. It is interposed between the surfaces. These output shaft support members are substantially annular members along the outer peripheral surface of the output shaft 30 and the inner peripheral surface of the housing member 40, and the first output shaft support member 61 includes a space for covering the fixed element 51. 59 and approximately the same position in the axial direction (see FIGS. 1 and 2). The second output shaft support member 63 is disposed at the axial end portion (right end portion in FIG. 1) of the housing member 40 with a space in the axial direction from the first output shaft support member 61. The first output shaft support member 61 may be a substantially C-shaped member having a slit extending in the axial direction. In this case, the first output shaft support member 61 can be attached to the nut 3 by expanding the slit.

  The first output shaft support member 61 is fixed to the outer peripheral surface of the output shaft 30 and is loosely fitted to the inner peripheral surface of the housing member 40. On the other hand, the second output shaft support member 63 is fixed to the inner peripheral surface of the housing member 40 and is loosely fitted to the outer peripheral surface of the output shaft 30. Furthermore, the first output shaft support member 61 and the second output shaft support member 63 are made of a material (for example, a resin such as fluororesin or polyacetal) that has excellent sliding characteristics and is less likely to cause friction and wear. In addition, friction is less likely to occur between the housing member 40 and the housing member 40.

  A rolling bearing 21 is attached to a portion in the vicinity of an end portion (left end portion in FIG. 1) located outside the hollow interior 30a of the output shaft 30 among both ends of the screw shaft 1. That is, the inner ring of the rolling bearing 21 is fitted to the screw shaft 1. The rolling bearing 21 is accommodated in a bearing casing member 22. That is, the outer ring of the rolling bearing 21 is fitted to the inner surface of the bearing casing member 22. Since the outer peripheral surface of the bearing casing member 22 is fitted to the inner peripheral surface of the housing member 40, the screw shaft 1 is rotatably supported by the housing member 40 via the rolling bearing 21.

  Further, at both ends of the screw shaft 1, the rotational force transmitting portion 20 is provided at the outermost end portion of the end portion located outside the hollow interior 30 a of the output shaft 30 (that is, further outside in the axial direction of the bearing casing member 22). Is attached to the screw shaft 1 so as to receive a rotational force from a drive source such as an electric motor (not shown) and transmit it to the screw shaft 1. When the screw shaft 1 is rotated by the input rotational force, the nut 3 is linearly moved along the screw shaft 1 accordingly.

  The linear movement direction of the nut 3 is determined by the rotation direction of the screw shaft 1. When the nut 3 moves linearly, the axial force is transmitted to the output shaft 30 by the fixing element 51, and the output shaft 30 moves linearly with the nut 3, so that the axial force is output from the output shaft 30. Further, the gear may be connected to a drive source such as an electric motor through an assembled reduction gear, or may be directly connected by a coupling or the like.

  At this time, since the first output shaft support member 61 is attached to the outer peripheral surface of the output shaft 30 (for example, as shown in FIG. 2, the two members extending in the circumferential direction formed on the outer peripheral surface of the output shaft 30 The first output shaft support member 61 may be mounted between the annular protrusions 30b), and moves in the axial direction together with the output shaft 30 while sliding with the inner peripheral surface of the housing member 40. Further, since the second output shaft support member 63 is fixed to the inner peripheral surface of the housing member 40, the second output shaft support member 63 does not move in the axial direction, and slides with the outer peripheral surface of the output shaft 30 as the output shaft 30 moves. To do.

  When the first output shaft support member 61 moves in the axial direction together with the output shaft 30 and reaches the axial position where the second output shaft support member 63 is attached, the first output shaft support member 61 is moved to the second output shaft. It interferes with the support member 63. Therefore, the moving distance of the first output shaft support member 61 until it interferes with the second output shaft support member 63 is the stroke amount of the actuator.

  In the actuator of this embodiment, the nut 3 is enclosed in the hollow interior 30a of the output shaft 30, the nut 3 and the output shaft 30 are connected by the fixed element 51, and the fixed element 51 is further connected to the first output shaft support member 61. It is possible to reduce the size. In addition, since the first output shaft support member 61 and the second output shaft support member 63 can be arranged with a large axial distance, the stroke amount is small despite the small size of the actuator of this embodiment. large.

  Further, when the connecting method of the nut 3 and the output shaft 30 is screwed, it is difficult to determine the phase of the nut 3 and the output shaft 30, and therefore a phase determining mechanism needs to be provided separately. If the connection method using the above is used, it is not necessary to separately provide a phasing mechanism. Furthermore, when the connection method of the nut 3 and the output shaft 30 is screwed, the fastening torque of both screws provided on the nut 3 and the output shaft 30 is managed, or in some cases, from the viewpoint of safety design, Although it is necessary to separately provide a separation prevention mechanism for both screws, it is not necessary to manage the fastening torque or install a separation prevention mechanism as long as the connection method uses the fixing element 51 as described above.

Furthermore, since the fixed element 51 is covered by the first output shaft support member 61, there is almost no possibility that the fixed element 51 falls out of the space 59.
Furthermore, since the annular protrusion 30b for attaching the first output shaft support member 61 is formed integrally with the output shaft 30 by a method such as machining, the first output shaft support member 61 is attached to the output shaft 30. It is possible to prevent the misalignment between the two at the time. Therefore, the first output shaft support member 61 is not easily damaged due to the misalignment of the both, and the actuator has a long life.

  Further, the actuator of the present embodiment is provided with means for suppressing squeezing of the ball screw 10. In other words, the radial clearance between the outer peripheral surface of the nut 3 and the inner peripheral surface of the output shaft 30 is larger than the radial clearance between the outer peripheral surface of the first output shaft support member 61 and the inner peripheral surface of the housing member 40. And is set larger than the radial clearance between the inner peripheral surface of the second output shaft support member 63 and the outer peripheral surface of the output shaft 30. With such a configuration, even when galling acts on the output shaft 30, galling becomes difficult to act on the ball screw 10, and an increase in surface pressure due to galling can be suppressed. Therefore, the actuator of this embodiment has a long life.

Next, the axial force transmission element 51 which is a characteristic part of the present invention will be described with reference to FIGS.
The above-described nut 3 opens to the axial end surface exposed to the outside of the output shaft 30 among the both axial end surfaces of the nut 3, that is, the end surface on the side not facing the hollow interior 30 a of the output shaft 30. A communication hole 70 is provided so as to extend in the direction and communicate with the space 59. The communication hole 70 is provided for all the spaces 59, and at least one communication hole 70 is provided for each space 59. A pressing pin 71 for pressing the fixing element 51 in the axial direction is press-fitted from the opening of the communication hole 70 on the axial end face side of the nut 3. By the press-fitted pressing pin 71, the fixing element 51 is fixed so as to be in close contact with the axial wall surface of the space 59 without a gap.

  With such a configuration, the fixing element 51 can be attached without play in the axial direction. As a result, transmission efficiency is improved and responsiveness is improved. Further, fretting wear can be suppressed and high responsiveness can be maintained over a long period of time. Furthermore, since the fixing element 51 is pressed with the pressing pin, the fixing element 51 can be easily fixed regardless of dimensional errors of the nut 3, the output shaft 30, the fixing element 51, and the like. As a result, an unnatural load is not generated in the ball screw portion, and galling can be prevented.

The cross-sectional shape of the communication hole 70 and the pressing pin 71 is preferably a circle from the viewpoint of workability, but may be a shape that can prevent relative rotation of a polygon, a spline, or the like, or may be an irregular fitting. Alternatively, the fixing element 51 may be pressed and fixed while fixing the pressing pin 71 by cutting a female screw in the communication hole 70 and a male screw on the outer periphery of the pressing pin 71 and screwing them together. Further, the female screw and the male screw may be provided on the entire communication hole 70 and the pressing pin 71 or may be provided on a part thereof. Furthermore, the communication hole 70 and the pressing pin 71 may be press-fitted as a tapered shape or a truncated pyramid shape whose diameter is reduced from the end face opening side of the nut 3. In these cases, the pressure input of the pressing pin 71 or the coupling force of the screwed portion by the screw of the pressing pin 71 is set to be larger than the load acting on the fixed element 51 when the actuator is used.

Further, it is preferable that the pressing pin 71 does not protrude from the opening in the axial direction end face side of the nut 3 of the communication hole 70. When making it protrude, it is preferable to make it protrude in the range which does not contact the casing member 22 for bearings.

Further, a lid member that covers the opening of the communication hole 70 may be provided on the end surface of the nut 3 on the opening side of the communication hole 70, and the lid member may be fixed to the nut 3 with a bolt or the like. Thereby, the pressing pin 71 can be prevented from coming off. In this case, the coupling force by screwing the bolt and nut is set to be larger than the load acting on the fixed element 51 when the actuator is used.

[Second Embodiment]
Since the structure, operation, and effect of the actuator of the second embodiment are substantially the same as those of the actuator of the first embodiment, only different parts will be described and description of the same parts will be omitted.
In the actuator according to the present embodiment, using the communication hole 70, it is confirmed at the time of assembly that the fixing element 51 is assembled without omission in all the spaces 59. Below, the confirmation method is demonstrated, referring FIG.2 and FIG.5.

  If, for example, when the assembly of the output shaft unit is completed during the manufacture of the actuator, the rod-shaped member 72 is inserted into the communication hole 70, whether or not the fixing element 51 exists in the space 59 from the insertion depth of the rod-shaped member 72. Can be confirmed. Since the communication holes 70 are provided for all the spaces 59, it can be easily confirmed whether or not the fixing elements 51 are assembled in all the spaces 59. However, it is preferable to confirm whether or not the fixing element 51 exists in the space 59, and it is preferable to individually check each fixing element 51. The confirmation is performed by simultaneously inserting the rod-shaped members 72 into the plurality of communication holes 70. That is not preferable.

  In addition, it is preferable that the pressing pin 71 has the function of the above-described rod-shaped member 72. That is, the fixing element 51 is pressed in the axial direction by the pressing pin 71 and whether or not the fixing element 51 exists in the space 59 is confirmed by the pressing depth of the pressing pin 71. Thereby, the work of assembling the fixing element 51 without backlash and the work of preventing the shortage of the fixing element 51 can be performed simultaneously and easily.

In addition, said 1st and 2nd embodiment showed an example of this invention, Comprising: This invention is not limited to both said embodiment. For example, the communication shaft 70 provided in the nut 3 in both the above embodiments may be provided in the output shaft 30. Further, as shown in FIG. 1, the actuators of both the above embodiments may be provided with a seal member that seals the opening of the gap between the output shaft 30 and the housing member 40. Further, a bellows-like member such as a bellows that covers the opening of the gap between the output shaft 30 and the housing member 40 and that expands and contracts according to the advancement and retraction of the output shaft 30 may be provided.

  Furthermore, instead of the ball screw 10, a slide screw, a roller screw, or the like can be used for the actuator of this embodiment. The type of the rolling bearing 21 is not particularly limited, and may be a ball bearing such as a deep groove ball bearing, an angular ball bearing, a self-aligning ball bearing, a cylindrical roller bearing, a tapered roller bearing, a needle roller bearing, A roller bearing such as a self-aligning roller bearing may be used. Alternatively, a sliding bearing may be used instead of the rolling bearing 21.

  Furthermore, in the actuators of the above-described embodiments, the first output shaft support member 61 is a member having a substantially C-shaped cross section. You may comprise by the shape of the cross section cut | disconnected by the plane to do. That is, the first output shaft support member 61 may be configured by arranging a plurality of cross-sectional arc-shaped members as a whole so as to form a substantially annular shape.

DESCRIPTION OF SYMBOLS 1 Screw shaft 3 Nut 10 Ball screw 20 Rotational force transmission part 21 Rolling bearing 22 Bearing casing member 30 Output shaft 30a Hollow inside 40 Housing member 51 Fixed element 53 Fixed element 55 Recessed part 57 Through hole 59 Space 61 First output shaft support member 63 Second output shaft support member 70 Communication hole 71 Press pin 72 Bar-shaped member 81 First flange 82 Second flange

Claims (2)

In an actuator that converts rotational motion into linear motion,
A substantially cylindrical or substantially rectangular tubular housing member;
A screw shaft that is coaxially arranged in the internal space of the housing member and receives rotational force;
A nut engaged with the screw shaft so as to linearly move along the screw shaft as the screw shaft is rotated by the rotational force;
A hollow output shaft connected to the nut and linearly moving with the nut to output an axial force;
An output shaft support member interposed between an outer peripheral surface of the output shaft and an inner peripheral surface of the housing member, and supporting the output shaft to the housing member;
And an actuator characterized by satisfying the following four conditions A, B, C, and D:
Condition A: The nut is enclosed in the hollow interior of the output shaft.
Condition B: A space is formed that includes a recess formed in the outer peripheral surface of the nut and a through hole that is continuous with the recess and penetrates the output shaft in the radial direction, and a fixing element is provided in the space. The nut and the output shaft are engaged and connected by the fixing element.
Condition C: A communication hole that opens to an axial end surface exposed to the outside of the output shaft among both axial end surfaces of the nut and communicates with the space is provided for the space.
Condition D: A pressing pin that presses the fixing element in the axial direction is press-fitted into the communication hole.   2. The method of manufacturing an actuator according to claim 1, wherein the pressing pin is inserted into the communication hole and the presence or absence of the fixing element is confirmed.

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