Extendable and retractable member

Abstract

In order to provide an extendable and retractable member that is used in a vehicle and in which damage to a motor is suppressed when movement on a door side is transmitted to the motor side, an extendable and retractable member 1 according to the present disclosure is provided with a speed reduction mechanism 30, the speed reduction mechanism 30 is provided with a sun gear portion 31 that has a sun gear 31A, and a planetary gear portion 32 that rotates around the sun gear 31A, the sun gear portion 31 is provided with an attachment portion 31B that is attached to a rotary shaft 20S of a motor 20, the planetary gear portion 32 is provided with a body portion 32A that has a receiving hole portion 32A11 for receiving the attachment portion 31B, and the attachment portion 31B can abut the receiving hole portion 32A11.

Description

Telescopic member

[0001] The present disclosure relates to a telescopic member for use in vehicles.

[0002] Patent Document 1 discloses a spindle drive for a movable member of an automobile, comprising a drive motor for generating a driving force along a geometric spindle axis, the drive motor having a spindle-spindle nut transmission mechanism connected downstream, wherein two connecting portions for leading out the driving force are provided, an inner housing coupled to one of the connecting portions and an outer housing coupled to the other connecting portion are provided, and when actuated by the motor, the inner housing telescopically moves within the outer housing. In the spindle drive for a movable member of an automobile, at least one of the two housings is formed of at least two pieces, is correspondingly constituted by a first housing portion made of a first material over a first axial housing section, and is constituted by a second housing portion made of a second material over a second axial housing section, and the first axial housing section is always arranged to be located outside the force transmission path for the driving force. There is disclosed such a spindle drive for a movable member of an automobile.

[0003] Patent Document 2 also discloses a speed reducer used for an electric gate of a vehicle or the like, which reduces the speed of rotation of a motor by a two-stage planetary gear mechanism arranged in parallel in the axial direction and outputs the rotation. The speed reducer comprises: a cylindrical resin case that incorporates the two-stage planetary gear mechanism and is provided with at least one of a cover portion and a bottom portion at each of both axial ends thereof; and a reinforcing component formed of a material having a higher Young's modulus than the material of the case and extending along at least a part of the inner circumferential surface of the case at the axial center portion of the case.

[0004] In Patent Document 2, the reinforcing component formed of a material having a higher Young's modulus than the material of the case and extending along at least a part of the inner circumferential surface of the case at the axial center portion of the case is provided, so that mechanical noise during operation of the motor is reduced. However, there is no arrangement to suppress the runout of the sun gear, and all of the runout is transmitted to the rotating shaft of the motor.

[0005] Japanese Patent Publication No. 5963880, Japanese Unexamined Patent Publication No. 2021-121741

[0006] Furthermore, in recent years, the noise reduction performance of vehicles such as automobiles has improved, and for example, high noise reduction performance is now required for the operating noise of expandable components (such as spindle drives) installed between the back door and the vehicle body.

[0007] Generally, in motor-driven expandable members, as seen in Patent Document 2, a two-stage reduction mechanism is provided to transmit the rotation of the motor, and this reduction mechanism is one of the sources of noise.

[0008] Furthermore, since the deceleration mechanism on the high-speed stage side, which performs the first deceleration, is a source of noise that is noticeable to people, we have been considering eliminating the high-speed stage and using only one deceleration mechanism with a large reduction ratio.

[0009] As a result, an improvement in noise reduction was observed, but it was found that there is a risk of damaging the motor when movement from a person manually moving the back door or other parts is transmitted to the motor.

[0010] This disclosure has been made in view of these circumstances, and one of its purposes is to provide an expandable member for use in a vehicle that suppresses damage to the motor when the movement of the door is transmitted to the motor.

[0011] The telescopic member of this disclosure is a telescopic member for use in a vehicle, the telescopic member comprising: an extension mechanism provided on one side; a motor provided on the other side for driving the extension mechanism; and a reduction mechanism interposed between the extension mechanism and the motor, the reduction mechanism comprising: a sun gear portion having a sun gear; and a planetary gear portion rotating around the sun gear, the sun gear portion comprising: a mounting portion provided on the other side of the sun gear and attached to the rotating shaft of the motor, the planetary gear portion comprising: a plurality of planetary gears provided corresponding to the sun gear; and a main body portion that rotatably supports the planetary gears and has a receiving hole portion on the other side for receiving the mounting portion, the mounting portion being able to abut against the receiving hole portion.

[0012] According to this disclosure, an expandable member for use in a vehicle is provided that suppresses damage to the motor when the movement from the door side is transmitted to the motor side.

[0013] This is a diagram showing the expandable member of an embodiment according to the present disclosure. This is an exploded perspective view of the reduction mechanism of an embodiment according to the present disclosure. This is a perspective view of the sun gear portion of an embodiment according to the present disclosure. This is a perspective view of the planetary gear portion of an embodiment according to the present disclosure. This is an exploded perspective view of the planetary gear portion of an embodiment according to the present disclosure. This is a perspective view showing the meshing state of the planetary gear and sun gear of an embodiment according to the present disclosure. This is a perspective view of the ring gear portion of an embodiment according to the present disclosure. This is a cross-sectional view of the ring gear portion of an embodiment according to the present disclosure along its longitudinal direction. This is a perspective view of the stop ring portion of an embodiment according to the present disclosure. This is a cross-sectional view showing the stop ring portion engaged with the ring gear portion of an embodiment according to the present disclosure. This is a cross-sectional view of the reduction mechanism of an embodiment according to the present disclosure along its longitudinal direction.

[0014] Hereinafter, embodiments for implementing this disclosure (hereinafter referred to as "Embodiments") will be described in detail with reference to the attached drawings. Throughout the description of the embodiments, the same elements are denoted by the same numbers or reference numerals.

[0015] Furthermore, the dimensional ratios in the drawings differ from the actual dimensional ratios and are merely for illustrative purposes to make the explanation easier to understand; there is no guarantee that identical parts are depicted with the same dimensions across different drawings.

[0016] Furthermore, for the sake of readability, in drawings, only some of the parts with the same attribute that exist in multiple locations may be assigned reference numerals.

[0017] <<Embodiment>> The expandable member 1 of the embodiment according to this disclosure will be described with reference to Figures 1 to 11.

[0018] For example, the expandable member 1 (also called a spindle drive) of the embodiment is preferably used to open and close the back door of a vehicle such as a hatchback, when it is installed between the back door and the vehicle body, but its use is not limited to the back door.

[0019] Figure 1 is a diagram showing an expandable member 1 of an embodiment according to the present disclosure, and the expandable mechanism 10 is shown in a cross-sectional view so that the internal state can be seen.

[0020] In the following, one direction of expansion and contraction of the expandable member 1 will be referred to as one side (left side in each figure), and the opposite direction will be referred to as the other side (right side in each figure).

[0021] However, "one side" and "the other side" merely indicate a relative positional relationship; the other side should be understood as the opposite side of one side.

[0022] Therefore, in each diagram, if one side is to be considered the other side, then the other side should be considered the one side, and in the explanation, one side should be read as the other side, and the other side as the one side.

[0023] As shown in Figure 1, the expandable member 1 of this embodiment includes joints J provided at both ends and used when attaching to a vehicle or the like, an expandable mechanism 10 provided on one side between the joints J, a motor 20 provided on the other side between the joints J to drive the expandable mechanism 10, and a reduction mechanism 30 interposed between the expandable mechanism 10 and the motor 20.

[0024] [Telescopic Mechanism 10] The telescopic mechanism 10 comprises a screw lead 11 (also called a lead screw) that rotates with the rotational force of a motor 20 transmitted via a reduction mechanism 30, and a movable pipe 12 which has a screw nut 12A at the other end that screws onto the screw lead 11, and moves back and forth in the longitudinal direction of the screw lead 11 as the screw lead 11 rotates.

[0025] Furthermore, the telescopic mechanism 10 includes a compression coil spring 13 provided to house the screw lead 11 and the movable pipe 12, a first outer pipe 14 having a ring-shaped first flange portion 14A at the other end that receives the compression coil spring 13 and covering the area corresponding to the screw lead 11, and a second outer pipe 15 that covers the area corresponding to the movable pipe 12 and can be housed inside the first outer pipe 14.

[0026] The second outer pipe 15 has a ring-shaped second flange portion 15A at one end to receive the compression coil spring 13. The joint J on one side is fixed to one end of the movable pipe 12.

[0027] [Motor 20] Although not shown in the illustration, the motor 20 is a typical inner rotor type motor and comprises a casing, a stator housed within the casing, and a rotor rotatably mounted within the stator and having a rotating shaft 20S (also called a rotor shaft). The joint J on the other side is fixed to the other end of the motor 20.

[0028] [Reduction mechanism 30] Figure 2 is an exploded perspective view of the reduction mechanism 30 of an embodiment according to the present disclosure, and also shows a part of the rotating shaft 20S of the motor 20.

[0029] As shown in Figure 2, the reduction mechanism 30 includes a sun gear section 31, a planetary gear section 32, a ring gear section 33, and a stop ring section 34.

[0030] (Sun Gear Section 31) Figure 3 is a perspective view of the sun gear section 31 of an embodiment according to the present disclosure. As shown in Figure 3, the sun gear section 31 having a sun gear 31A is provided on the other side of the sun gear 31A and includes a mounting section 31B which is attached to the rotating shaft 20S of a motor 20 (not shown).

[0031] The sun gear 31A is a helical gear having a pair of opposing teeth T around a central axis AX, with the pair of teeth T formed to trace a spiral around the central axis AX. The sun gear 31A may have three or more teeth T.

[0032] Furthermore, the mounting portion 31B includes a bottomed cylindrical portion 31B1 having a recess for press-fitting and fixing the rotating shaft 20S inside, and a flange portion 31B2 provided on the other side of the bottomed cylindrical portion 31B1 and having an opening for inserting the rotating shaft 20S into the recess.

[0033] (Planetary Gear Section 32) Figure 4 is a perspective view of the planetary gear section 32 of the embodiment according to the present disclosure. Figure 5 is an exploded perspective view of the planetary gear section 32 of the embodiment according to the present disclosure. Figure 6 is a perspective view showing the meshing state of the planetary gear PG and the sun gear 31A of the embodiment according to the present disclosure.

[0034] As shown in Figure 6, the planetary gear section 32 includes a plurality of planetary gears PG provided in correspondence with the sun gear 31A, and as shown in Figure 4, a main body section 32A that rotatably supports the planetary gears PG and has a receiving hole section 32A11 on the other side for receiving the mounting section 31B of the sun gear section 31 (more specifically, the bottomed cylindrical section 31B1).

[0035] Specifically, as shown in Figure 5, the main body 32A comprises a cylindrical body 32A1 having a pair of openings on its side capable of receiving a pair of planetary gears PG, and a bearing body 32A2 having a pair of shaft portions 32A21 that rotatably support the planetary gears PG.

[0036] Then, as shown by the thick arrows, with the pair of planetary gears PG positioned on the cylindrical body 32A1 side from the opening, the main body 32A is formed by connecting the bearing body 32A2 to the other side of the cylindrical body 32A1 so that the shaft portion 32A21 is inserted into the central through-hole of the planetary gears PG.

[0037] Furthermore, the other end of the screw lead 11 is connected to one end of the main body 32A (more specifically, one end 32A12 of the cylindrical body 32A1) by a connecting member (not shown).

[0038] Furthermore, the receiving hole 32A11 for receiving the mounting portion 31B (more specifically, the bottomed cylindrical portion 31B1) of the sun gear portion 31 shown in Figure 3 is provided at the other end of the main body portion 32A (more specifically, the other end 32A13 of the cylindrical body 32A1), as shown in Figure 5.

[0039] On the other hand, as shown in Figure 6, the pair of planetary gears PG are arranged facing each other around the sun gear 31A. Here, in order to make the number of teeth T (see Figure 3) of the sun gear 31A the same as the number of planetary gears PG, if the number of teeth T of the sun gear 31A is 3 or more, the number of planetary gears PG will also be 3 or more.

[0040] Furthermore, both of the pair of planetary gears PG are helical gears formed such that teeth form a spiral around the center, and mesh with the helical gear of the sun gear 31A.

[0041] As described above, since both the sun gear 31A and the planetary gears PG are helical gears, it is possible to easily maintain a state where teeth are constantly in contact with each other during rotation of the gears (during rotation of the sun gear 31A and the planetary gears PG), and separation between teeth can be significantly reduced.

[0042] Therefore, collision between teeth when they re-engage after being separated can be reduced, so that noise reduction performance can be improved.

[0043] Moreover, by setting the number of teeth T of the sun gear 31A to two and the number of planetary gears PG also to two, thereby keeping the number of gears to a minimum, the number of collisions between teeth can be further reduced, and high noise reduction performance can be obtained.

[0044] When the sun gear 31A rotates, a force is applied to the planetary gears PG so as to rotate around the sun gear 31A, and the main body portion 32A rotates around the sun gear 31A together with the planetary gears PG while maintaining the positional relationship of the pair of planetary gears PG.

[0045] In this way, the main body portion 32A rotatably supports the pair of planetary gears PG relative to the sun gear 31A, and the entire planetary gear portion 32 rotates around the sun gear 31A.

[0046] As described above, the other side of the screw lead 11 is connected to one end portion on one side of the main body portion 32A (more specifically, one end portion 32A12 on one side of the cylindrical body 32A1) by a connecting member (not shown), so the screw lead 11 rotates as the planetary gear portion 32 rotates around the sun gear 31A.

[0047] (Ring Gear Portion 33) FIG. 7 is a perspective view of the ring gear portion 33 according to the embodiment of the present disclosure. FIG. 8 is a cross-sectional view along the longitudinal direction of the ring gear portion 33 according to the embodiment of the present disclosure.

[0048] The ring gear portion 33 is a member that accommodates the planetary gear portion 32 and guides rotation of the planetary gear portion 32 around the sun gear 31A.

[0049] Therefore, as shown in FIGS. 7 and 8, the ring gear portion 33 includes a guide gear portion 33A that is provided corresponding to the planetary gear PG and has a guide gear GG for guiding rotation of the planetary gear portion 32.

[0050] The ring gear portion 33 further includes: a base end portion 33B provided on the other side of the guide gear portion 33A and receiving the other side of the planetary gear portion 32; and a receiving portion 33C provided on one side of the guide gear portion 33A and receiving one end portion on one side of a main body portion 32A of the planetary gear portion 32 (more specifically, one end portion 32A12 on one side of a cylindrical body 32A1).

[0051] As shown in FIGS. 7 and 8, the guide gear GG is a helical gear formed to draw a spiral along the longitudinal direction (the left-right direction in FIG. 8) of the guide gear portion 33A.

[0052] Since the ring gear portion 33 is fixed, the guide gear GG of the guide gear portion 33A integrally formed on the ring gear portion 33 is also in a fixed state, and the planetary gear PG rotates within the guide gear GG along the guide gear GG.

[0053] When the planetary gear PG rotates within the guide gear GG along the guide gear GG as the sun gear 31A rotates, since both the planetary gear PG and the guide gear G are helical gears, a state in which the teeth of the planetary gear PG and the guide gear G are always in contact can be easily maintained, and separation between adjacent teeth can be greatly reduced.

[0054] Therefore, collision between teeth when they re-engage after separation can be reduced, so that noise reduction performance can be improved.

[0055] Moreover, as described above, in combination with limiting the number of gears to a minimum by setting the number of planetary gears PG to two, the number of collisions between teeth can be further reduced, and high noise reduction performance can be obtained.

[0056] As shown in Figures 7 and 8, the base end portion 33B is provided on one end face portion 33B1, and on the receiving hole portion 32A11 side of the main body portion 32A of the planetary gear portion 32 shown in Figure 4, there is an outlet hole 33B11 for leading out the mounting portion 31B of the sun gear portion 31 shown in Figure 3 (more specifically, the bottomed cylindrical portion 31B1).

[0057] As shown in Figure 8, the base end portion 33B is provided on the other side of the outlet hole 33B11 and has a housing space SP that accommodates the flange portion 31B2 of the mounting portion 31B of the sun gear portion 31 shown in Figure 3.

[0058] On the other hand, as shown in Figure 8, the ring gear portion 33 includes an engaging claw 33C1 provided on one side of the receiving portion 33C that engages with a plurality of stop ring portions 34 (described later) that are oriented in the circumferential direction, and a protrusion 33D that extends from the receiving portion 33C to one side and restricts the circumferential movement of the plurality of stop ring portions 34 provided in the circumferential direction.

[0059] (Stop ring portion 34) Figure 9 is a perspective view of the stop ring portion 34 of the embodiment according to the present disclosure. Figure 10 is a cross-sectional view showing the stop ring portion 34 of the embodiment according to the present disclosure engaged with the ring gear portion 33, and also shows the cylindrical body 32A1 of the planetary gear portion 32.

[0060] As shown in Figure 9, the stop ring portion 34 is an outer ring-shaped member, and as shown in Figure 10, it is attached to one side of the receiving portion 33C of the ring gear portion 33, and is a member that prevents the planetary gear portion 32 from coming off the ring gear portion 33.

[0061] Furthermore, the other end of the screw lead 11 is connected by a connecting member (not shown) to one end of the main body 32A of the planetary gear section 32 (more specifically, one end 32A12 of the cylindrical body 32A1) through an opening 34OP provided in the center of the stop ring section 34.

[0062] Specifically, the stop ring portion 34 includes multiple engaging claws 34A provided in the circumferential direction that engage with engaging claws 33C1 provided on one side of the receiving portion 33C of the ring gear portion 33, and recesses 34B formed on the side and recessed on the inside that receive multiple convex portions 33D of the ring gear portion 33 provided in the circumferential direction, as shown in Figure 9.

[0063] Furthermore, as shown in Figure 10, the stop ring portion 34 has a thickness D1 greater than the thickness D2 of the receiving portion 33C of the ring gear portion 33, thereby suppressing deformation of the receiving portion 33C of the ring gear portion 33 due to the stress when the planetary gear portion 32 rotates. Consequently, the looseness of the planetary gear portion 32 when it rotates around the sun gear 31A is suppressed.

[0064] Incidentally, while generally two sets of sun gears, planetary gears, and ring gears are provided to perform reduction in two stages, the reduction mechanism 30 of this embodiment is a reduction mechanism with a large reduction ratio, provided by only one sun gear section 31, one planetary gear section 32, and one ring gear section 33.

[0065] As a result, when performing two-stage reduction, the reduction mechanism for the high-speed stage, which generates noise in frequency ranges that are particularly noticeable to people, is omitted, resulting in improved quietness. However, the sun gear 31A of the sun gear section 31 is longer than the sun gear used in conventional two-stage reduction systems.

[0066] As explained earlier, in this embodiment, the sun gear 31A, planetary gear PG, and guide gear GG are all helical gears to enhance quiet operation. However, helical gears transmit motion not only in the rotational direction but also in the thrust direction.

[0067] Figure 11 is a cross-sectional view of the reduction mechanism 30 of an embodiment according to the present disclosure, along its longitudinal direction. For example, when a person moves the back door by hand, as the movement from the door side is transmitted to the motor 20 side, the sun gear 31A moves in a way that causes it to bend, and as the force is transmitted, a force is applied that causes the rotation shaft 20S of the motor 20 (not shown) to bend, as shown by the double arrows in Figure 11.

[0068] As a result, the motor 20 (not shown) may be damaged, such as by deformation of its rotating shaft 20S. Such damage to the motor 20 may cause abnormal noise, even if it does not render it unable to rotate.

[0069] Therefore, in this embodiment, damage to the motor 20 is suppressed by making it difficult for a force that would cause the rotating shaft 20S to bend to be applied to the rotating shaft 20S of the motor 20.

[0070] Specifically, the first width is defined as the gap between the mounting portion 31B of the sun gear portion 31 (more specifically, the bottomed cylindrical portion 31B1) and the receiving hole portion 32A11 of the planetary gear portion 32 (see the dotted line enclosed area A1 in Figure 11), and the second width is defined as the gap between one end of the main body portion 32A of the planetary gear portion 32 (more specifically, one end of the cylindrical body 32A1 32A12) and the receiving portion 33C of the ring gear portion 33 (see the dotted line enclosed area A2 in Figure 11). The first width is set to be smaller than the second width.

[0071] More specifically, the first width, which is the width of the gap in the receiving hole 32A11 of the planetary gear section 32 (see the dotted line-enclosed area A1 in Figure 11), is such that when the sun gear section 31 is bent, the mounting portion 31B of the sun gear section 31 comes into contact with the inner surface of the receiving hole 32A11.

[0072] In other words, the mounting portion 31B of the sun gear portion 31 is capable of contacting the receiving hole portion 32A11 of the planetary gear portion 32.

[0073] In this way, while ensuring clearance (second width) between the planetary gear section 32 and the ring gear section 33 for rotation, even if a force is applied from the planetary gear PG side to cause the sun gear 31A to bend, the first width section with a small clearance is provided just before it is transmitted to the rotating shaft 20S, thereby restricting the bending at the mounting section 31B of the sun gear section 31 (more specifically, the bottomed cylindrical section 31B1).

[0074] Therefore, the transmission of a movement that would cause the rotating shaft 20S to bend from the sun gear 31A side to the rotating shaft 20S is suppressed, and damage to the motor 20 (not shown), such as deformation of the rotating shaft 20S, can be avoided.

[0075] Furthermore, as shown in Figure 8, the ring gear portion 33 is provided on the guide gear portion 33A and includes a housing portion 33A1 that accommodates the other end of the main body portion 32A of the planetary gear portion 32 (more specifically, the other end 32A13 of the cylindrical body 32A1 (see Figures 5 and 11)) located between the guide gear GG and the base end portion 33B.

[0076] Furthermore, as shown in Figure 11, the width of the gap (also called the third width) between the housing portion 33A1 (see Figure 8) and the other end of the main body portion 32A of the planetary gear portion 32 (more specifically, the other end portion 32A13 of the cylindrical body 32A1) (see the dotted line enclosed portion A3 in Figure 11) is reduced, thereby further suppressing the rattle of the planetary gear portion 32 relative to the ring gear portion 33, and achieving high noise reduction performance. It is preferable that the third width be less than or equal to the second width.

[0077] Although the above description has been based on specific embodiments, this disclosure is not limited to the embodiments described above. This disclosure also includes modifications and improvements to the embodiments, which will be clear to those skilled in the art from the claims.

[0078] Furthermore, the following additional notes are disclosed with respect to the above embodiment. [Addendum 1] A telescopic member for use in a vehicle, wherein the telescopic member comprises: an extension mechanism provided on one side; a motor provided on the other side for driving the extension mechanism; and a reduction mechanism interposed between the extension mechanism and the motor, wherein the reduction mechanism comprises: a sun gear section having a sun gear; and a planetary gear section rotating around the sun gear, wherein the sun gear section comprises: a mounting section provided on the other side of the sun gear and attached to the rotating shaft of the motor, wherein the planetary gear section comprises: a plurality of planetary gears provided corresponding to the sun gear; and a main body section that rotatably supports the planetary gears and has a receiving hole section on the other side for receiving the mounting section, wherein the mounting section is capable of contacting the receiving hole section. [Addendum 2] The telescopic member according to Addendum 1, wherein the mounting section contacts the receiving hole section when the sun gear section is bent. [Note 3] The reduction mechanism comprises a ring gear portion that houses the planetary gear portion and guides the rotation of the planetary gear portion, the ring gear portion comprising a guide gear portion provided in correspondence with the planetary gear and having a guide gear that guides the rotation of the planetary gear portion, and a receiving portion provided on one side of the guide gear portion and receiving one end of the main body portion, the expandable member according to Note 1 or Note 2, wherein when the width of the gap between the mounting portion and the receiving hole portion is defined as the first width and the width of the gap between the one end and the receiving portion is defined as the second width, the first width is smaller than the second width. [Note 4] The expandable member according to Note 3, wherein the reduction mechanism comprises only one sun gear portion, planetary gear portion, and ring gear portion. [Note 5] The expandable member according to Note 3 or Note 4, wherein the sun gear, planetary gear, and guide gear are all helical gears. [Note 6] The reduction mechanism is provided with a stop ring portion attached to one side of the receiving portion to prevent the planetary gear portion from coming off the ring gear portion, and the thickness of the stop ring portion is greater than the thickness of the receiving portion, as described in any one of Notes 3 to 5. [Note 7] The expandable member described in any one of Notes 1 to 6, wherein the number of planetary gears is two.

[0079] Furthermore, the following additional information is disclosed regarding the above embodiments. [Note 1] A telescopic member for use in a vehicle, wherein the telescopic member comprises: a telescopic mechanism provided on one side; a motor provided on the other side for driving the telescopic mechanism; and a reduction mechanism interposed between the telescopic mechanism and the motor, wherein the reduction mechanism comprises: a sun gear section having a sun gear; a planetary gear section rotating around the sun gear; and a ring gear section housing the planetary gear section and guiding the rotation of the planetary gear section, wherein the sun gear section comprises a mounting section provided on the other side of the sun gear and attached to the rotating shaft of the motor, wherein the planetary gear section comprises: a plurality of planetary gears provided corresponding to the sun gear; and a main body section that rotatably supports the planetary gears and has a receiving hole section on the other side for receiving the mounting section, wherein the ring gear section comprises a guide gear section provided corresponding to the planetary gears and having a guide gear that guides the rotation of the planetary gear section, An expandable member comprising: a receiving portion provided on one side of the guide gear portion and receiving one end of the main body portion on one side, wherein when the width of the gap between the mounting portion and the receiving hole portion is defined as the first width and the width of the gap between the end and the receiving portion is defined as the second width, the first width is smaller than the second width. [Note 2] The expandable member according to Note 1, wherein the number of planetary gears is two. [Note 3] The expandable member according to Note 1 or Note 2, wherein the sun gear, the planetary gear, and the guide gear are all helical gears. [Note 4] The expandable member according to any one of Notes 1 to 3, wherein the reduction mechanism is attached to one side of the receiving portion and includes a stop ring portion that prevents the planetary gear portion from coming off the ring gear portion, and the thickness of the stop ring portion is greater than the thickness of the receiving portion.

[0080] 1...Extendable member, 10...Extendable mechanism, 20...Motor, 20S...Rotating shaft, 30...Reduction mechanism, 31...Sun gear section, 31A...Sun gear, 31B...Mounting section, 32...Planetary gear section, 32A...Main body section, 32A11...Receiving hole section, 32A12...One end section, 33...Ring gear section, 33A...Guide gear section, 33C...Receiving section, 34...Stop ring section, GG...Guide gear, PG...Planetary gear

Claims

1. A telescopic member for use in a vehicle, the telescopic member comprising: an extension mechanism provided on one side; a motor provided on the other side for driving the extension mechanism; and a reduction mechanism interposed between the extension mechanism and the motor, the reduction mechanism comprising: a sun gear section having a sun gear; and a planetary gear section rotating around the sun gear, the sun gear section comprising: a mounting section provided on the other side of the sun gear and attached to the rotating shaft of the motor, the planetary gear section comprising: a plurality of planetary gears provided corresponding to the sun gear; and a main body section that rotatably supports the planetary gears and has a receiving hole section on the other side for receiving the mounting section, the telescopic member wherein the mounting section can abut against the receiving hole section.

2. The expandable member according to claim 1, wherein the mounting portion abuts against the receiving hole portion when the sun gear portion is bent.

3. The reduction mechanism comprises a ring gear portion that houses the planetary gear portion and guides the rotation of the planetary gear portion, the ring gear portion comprising a guide gear portion provided in correspondence with the planetary gear and having a guide gear that guides the rotation of the planetary gear portion, and a receiving portion provided on one side of the guide gear portion and receiving one end of the main body portion, wherein when the width of the gap between the mounting portion and the receiving hole portion is defined as a first width, and the width of the gap between the one end and the receiving portion is defined as a second width, the first width is smaller than the second width, the expandable member according to claim 1 or claim 2.

4. The expandable member according to claim 3, wherein the reduction mechanism comprises only one sun gear section, one planetary gear section, and one ring gear section.

5. The expandable member according to claim 3, wherein the sun gear, planetary gear, and guide gear are all helical gears.

6. The reduction mechanism is provided with a stop ring portion attached to one side of the receiving portion to prevent the planetary gear portion from coming off the ring gear portion, and the thickness of the stop ring portion is greater than the thickness of the receiving portion, as described in claim 3.

7. The expandable member according to claim 1 or claim 2, wherein the number of planetary gears is two.

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