Vehicle height-adjusting device

Abstract

According to an embodiment of the present invention, a vehicle height-adjusting device capable of adjusting the height of a vehicle body may comprise: a first housing accommodating a motor or gears rotated by the motor; a screw shaft rotationally driven by the motor or the gears; a non-rotational type screw nut which is movable in the lengthwise direction of the screw shaft with respect to the screw shaft; a spring pad which is integrally attached onto the screw nut to be movable along with the screw nut; and a sealing boot which seals a space between the first housing and the spring pad.

Description

garage control device

[0001] The present invention relates to a vehicle height adjustment device for adjusting the height of a vehicle body, and more particularly, to an electric vehicle height adjustment device with improved durability and sealing properties.

[0002] When driving at high speeds, it is advantageous to lower the height of the vehicle body to reduce air resistance, and when driving on rough roads, it is advantageous to raise the height of the vehicle body to prevent damage to the lower part of the vehicle body. Therefore, the vehicle's suspension system may be equipped with a ride height adjustment device to adjust the height of the vehicle body.

[0003] Conventional vehicle height adjustment devices have been mainly formed with a structure that operates using air pressure generated by engine power. However, since these pneumatic vehicle height adjustment devices directly use engine power, they can cause a decrease in fuel efficiency and output, and if air pressure leaks due to defective or damaged parts, there is a problem that the height of the vehicle body cannot be adjusted smoothly.

[0004] To solve this problem, an electric vehicle height adjustment device has recently been proposed that uses an electric motor to move the vehicle body up and down to adjust the height of the vehicle body.

[0005] However, the garage adjustment device is mounted on the suspension of the vehicle, and is greatly affected by the vibration of the vehicle and is also exposed to external moisture and foreign substances. The conventionally known electric garage adjustment device has a complex structure and also has room for improvement in the sealing structure to prevent the penetration of external moisture or foreign substances, so it has poor durability and is at a high risk of failure as a result.

[0006] The present invention has been devised to solve the above-described conventional problems, and aims to provide a vehicle height adjustment device with improved durability and sealing properties.

[0007] One embodiment of the present invention is to provide an electric vehicle garage adjustment device with improved durability and sealing properties.

[0008] A vehicle height adjustment device (1) for adjusting the height of a vehicle according to one embodiment of the present invention may include a first housing (320) that accommodates an electric motor (100) or a gear (200) that is rotated by the electric motor (100), a screw shaft (500) that is rotationally driven by the motor (100) or the gear (200), a non-rotatable screw nut (600) that is configured to move in the longitudinal direction of the screw shaft (500) with respect to the screw shaft (500), a spring pad (700) that is integrally mounted on the screw nut (600) and is configured to move together with the screw nut (600), and a sealing boot (800) that is configured to seal a space between the first housing (320) and the spring pad (700).

[0009] In addition, the garage adjustment device (1) further includes a spring mounted between the spring pad (700) and the lower arm, and the screw nut (600) is prevented from rotating around the screw shaft (500) by the spring, so that it can move in the longitudinal direction of the screw shaft (500).

[0010] According to one embodiment of the present invention, the sealing boot (800) may be composed of a flexible bellows element.

[0011] In addition, a screw shaft thread portion (510) is formed on the outer surface of the screw shaft (500), and a screw nut thread portion (610) having a shape corresponding to the screw shaft thread portion (510) is formed on the inner surface of the screw nut (600), so that the screw nut (600) can be configured to be screw-coupled to the screw shaft (500).

[0012] According to another embodiment of the present invention, the garage control device (1) includes a plurality of electric elements between the screw nut (600) and the screw shaft (500),

[0013] The above plurality of electric motors may be configured to perform cloud motion to assist longitudinal relative movement between the screw shaft (500) and the screw nut (600).

[0014] The above spring may be a coil spring (900).

[0015] In addition, the electric motor (100) or the gear (200) rotated by the electric motor (100) and the first housing (320) accommodating the gear (200) inside are top-mounted assemblies fixed to the body side, and the first housing (320) includes an upper housing (322) and a lower housing (324), and the upper portion of the screw shaft (500) is rotatably coupled to the first housing (320), and a rim (326) protruding downward along the outer circumference of the lower surface of the lower housing (324) is formed, and one end of the sealing boot (800) can be fixed to the rim (326).

[0016] The other end of the above sealing boot (800) can be interposed and fixed between the screw nut (600) and the spring pad (700).

[0017] According to one embodiment of the present invention, the motor (100) or the gear (200) rotated by the motor (100) and the first housing (320) accommodating the gear (200) inside are a top mount assembly fixed to the body side, and the screw shaft (500), the screw nut (600), and the spring pad (700) can all be configured to be suspended from the top mount assembly.

[0018] According to one embodiment of the present invention, at least one hole (620) may be formed in the screw nut (600), and at least one protrusion (710 / 720) inserted into the at least one hole (620) may be formed on the upper surface of the spring pad (700).

[0019] A garage control device (1) according to one embodiment of the present invention further includes a cover (40), wherein the cover (40) is configured to cover at least a portion of the screw shaft (500), and at least a portion of the cover (40) can be interposed and fixed between the screw nut (600) and the spring pad (700).

[0020] In addition, as the screw shaft (500) rotates, the screw nut (600) can be configured to move up and down in the longitudinal direction with respect to the screw shaft (500) to adjust the height of the vehicle body.

[0021] The first housing (320) accommodates a gear (200) therein, and the garage control device (1) further includes a second housing (340) that accommodates a motor (100) and a drive shaft (10), and the second housing (340) can be configured to be suspended from the first housing (320).

[0022] In addition, according to one embodiment of the present invention, when the garage adjustment is 40 mm, the screw nut (600) and the screw shaft (500) may be formed so that the ratio (L2 / L1) of the length (L1) of the screw nut (600) and the length (L2) of the screw shaft is 2.3 or less. In addition, when the garage adjustment is 60 mm, the screw nut (600) and the screw shaft (500) may be formed so that the ratio (L2 / L1) of the length (L1) of the screw nut (600) and the length (L2) of the screw shaft is 2.9 or less.

[0023] According to one embodiment of the present invention, since all components except the spring are suspended from the top mount assembly, the garage adjustment device experiences relatively less vibration, and thus the durability of the garage adjustment device can be improved.

[0024] According to one embodiment of the present invention, compared to the conventional technology that implements the up-and-down movement of the nut through a complex structure in which both the shaft and the nut are driven by a motor, the up-and-down movement of the screw nut and the spring pad integrally mounted thereto is achieved through a simple structure, thereby reducing and simplifying the number of parts, and improving durability.

[0025] Since the sealing boot simply seals the space between the first housing and the spring pad, all parts that need to be protected from the ingress of moisture or foreign substances can be sealed from the outside, thereby improving the sealing performance.

[0026] FIG. 1 exemplarily illustrates the overall structure of a garage control device according to one embodiment of the present invention.

[0027] Fig. 2 illustrates an example of a cross-sectional structure of the garage control device illustrated in Fig. 1.

[0028] Figure 3 is an enlarged view of area A1 shown in Figure 2.

[0029] Fig. 4 illustrates an example of the contact structure of the spring pad and the spring of the garage control device illustrated in Fig. 1.

[0030] Fig. 5 illustrates a cross-sectional structure of a garage control device according to another embodiment of the present invention.

[0031] Figure 6 is an enlarged view of area A shown in Figure 5.

[0032] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0033] When an element is referred to as "on" or "on" another element, it includes not only the element directly on the other element, but also any intervening elements. Conversely, when an element is referred to as "directly on" or "directly on", it indicates that there are no intervening elements. "And / or" includes each and every combination of one or more of the mentioned items.

[0034] Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" may be used to readily describe the relationship of one component to another, as illustrated in the drawings. Spatially relative terms should be understood to include different orientations of the element during use or operation in addition to the orientations illustrated in the drawings. Like reference numerals refer to like components throughout the specification.

[0035] Although terms such as "first," "second," etc. are used to describe various components and / or sections, these components and / or sections are not limited by these terms. These terms are merely used to distinguish one component or section from another. Accordingly, it should be understood that a first component or first section referred to below may also be a second component or second section within the technical scope of the present invention. Furthermore, the term "about" in this specification should be understood to encompass the range of manufacturing tolerances within the technical field to which the present invention pertains.

[0036] The embodiments described herein will be described with reference to plan views and cross-sectional views, which are ideal schematic drawings of the present invention. Therefore, the shapes of the illustrated drawings may vary depending on manufacturing techniques and / or tolerances. Therefore, the embodiments of the present invention are not limited to the specific shapes illustrated, but also encompass variations in shape resulting from the manufacturing process. Accordingly, the regions illustrated in the drawings are schematic in nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of the regions of the configuration and are not intended to limit the scope of the invention.

[0037] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings.

[0038] Fig. 1 illustrates the overall structure of a garage control device according to one embodiment of the present invention. Fig. 2 illustrates a cross-sectional structure of the garage control device illustrated in Fig. 1. Fig. 3 is an enlarged view of area A1 illustrated in Fig. 2.

[0039] Referring to FIGS. 1 to 3, the structure of a vehicle height adjustment device (1) according to an embodiment of the present invention is exemplarily illustrated. As described below, the vehicle height adjustment device (1) according to an embodiment of the present invention is configured to be driven by an electric motor (100), and most of the components of the vehicle height adjustment device (1) are simplified and configured to be suspended from a vehicle body, thereby reducing the influence of vibrations and improving durability, and by changing the sealing structure, the risk of external moisture or foreign substances penetrating and remaining inside the vehicle height adjustment device can be reduced. This will be described in more detail below.

[0040] According to one embodiment of the present invention, a garage control device (1) may be configured to include an electric motor (100), one or more gears (200) connected to a rotor of the electric motor (100), a housing (300) accommodating the electric motor (100) and the gears (200), a screw shaft (500) rotationally driven by the electric motor (100) or the gears (200), a non-rotatable screw nut (600) configured to be movable in the longitudinal direction of the screw shaft (500) with respect to the screw shaft (500), a spring pad (700) integrally mounted on the screw nut (600) and configured to move together with the screw nut (600), and a sealing boot (800) configured to seal a space between the housing (300) and the spring pad (700).

[0041] According to one embodiment of the present invention, the electric motor (100) is a part that generates driving force for operating the garage control device (1), and may be configured to include a stator and a rotor similar to a conventional electric motor.

[0042] According to one embodiment of the present invention, the housing (300) may be composed of a first housing (320) for accommodating one or more gears (200) and a portion of a screw shaft (500), a second housing (340) for accommodating an electric motor (100) and at least a portion of a drive shaft (10) connected to the electric motor (100), and a third housing (360) for accommodating a controller (20) for controlling the electric motor.

[0043] The first housing (320) may be composed of an upper housing (322) and a lower housing (324), and all components of the garage adjustment device (1) except for the spring (e.g., a second housing, a third housing, etc. that accommodate a screw shaft, a screw nut, a spring pad, a cover, a motor, and a controller) may be configured to be suspended from the lower housing (324). In addition, the first housing (320) and its internal components may be composed of a top mount assembly that is fixed to a vehicle body.

[0044] Through this structure, all parts of the garage adjustment device (1) except the spring are a top mount assembly fixed to the vehicle body or suspended from the top mount assembly, and only the spring is fixed by being interposed between the lower arm (not shown) and the spring pad (700).

[0045] Since the lower arm is closer to the road surface than the vehicle body, it experiences more severe vibration than the vehicle body. However, since all components except the spring of the vehicle height adjustment device (1) according to one embodiment of the present invention are top-mounted assemblies or suspended from the top-mounted assemblies, it is relatively less affected by vibration, and thus the durability of the vehicle height adjustment device (1) can be improved.

[0046] According to one embodiment of the present invention, the lower housing (324) may be configured to have a through hole formed on its lower surface, such that the upper portion of the screw shaft (500) extends through the through hole. The screw shaft (500) may be rotatably fixed to the upper housing (322) and the lower housing (324) by a first bearing (330) and a second bearing (370) installed in the upper housing (322) and the lower housing (324), respectively. The screw shaft (500) may be configured to be rotationally driven by an electric motor (100) through a drive shaft (10) and a plurality of gears (200).

[0047] According to one embodiment of the present invention, a screw shaft thread portion (510) may be formed on the outer circumferential surface of a screw shaft (500), and a screw nut thread portion (610) having a shape corresponding to the screw shaft thread portion (510) may be formed on the inner circumferential surface of a screw nut (600). Accordingly, the screw nut (600) may be configured to be screw-coupled to the screw shaft (500).

[0048] The spring pad (700) may be configured to be integrally mounted on the screw nut (600) and move together with the screw nut (600). For example, at least one hole (620) may be formed on the lower surface of the screw nut (600), and at least one protrusion (710) may be formed on the upper surface of the spring pad (700) to be inserted into the hole (620) of the screw nut (600). Through this hole / protrusion structure, the spring pad (700) may be forcibly pressed into and fixed to the lower surface of the screw nut (600), and the spring pad (700) may move together with the screw nut (600).

[0049] According to one embodiment of the present invention, the screw nut (600) has a structure that is screw-connected with the screw shaft (500), but the screw nut (600) may be configured to be non-rotatable so as not to rotate around the screw shaft (500).

[0050] FIG. 4 exemplarily illustrates the contact structure of the spring pad and the spring of the garage adjustment device illustrated in FIG. 1. According to one embodiment of the present invention, the spring may be a coil spring (900), and the coil spring (900) is compressed by being pressurized by the load of the vehicle, so that the coil spring (900) strongly presses the spring pad (700) upward, so that even if the spring pad (700) receives rotational force through the screw nut (600) as the screw shaft (500) rotates, the spring pad (700) does not rotate. In addition, since the spring pad (700) is integrally mounted on the screw nut (600) in the present invention (as described above), if the spring pad (700) does not rotate, the screw nut (600) also does not rotate.

[0051] In addition, according to one embodiment of the present invention, a downwardly protruding downward protrusion (720) may be formed on the lower surface of the spring pad (700), and one end of the coil spring (900) may be configured to contact the downward protrusion (720). In addition, although not shown, an upwardly protruding upward protrusion may be formed on the upper surface of the lower arm, and the other end of the coil spring (900) may be configured to contact the upward protrusion. Through the above-described structure, when the coil spring (900) is interposed between the spring pad (700) and the lower arm, the coil spring (900) can be stably fixed in place. In addition, since this downward protrusion (720) is additionally configured to contact one end of the coil spring (900), the downward protrusion (720) can additionally function as a stopper that reliably prevents at least the spring pad (700) from rotating in one direction.

[0052] In this way, in the present invention, the screw nut (600) is configured to be non-rotatable through a simple structure in which the spring pad (700) is integrally mounted to the screw nut (600), and as the screw shaft (500) rotates, the screw nut (600) and the spring pad (700) integrally mounted thereto move up and down along the longitudinal direction of the screw shaft (500).

[0053] Therefore, compared to the conventional technology that implements the up-and-down movement of the nut through a complex structure, such as when both the shaft and the nut are driven by a motor, the up-and-down movement of the screw nut and the spring pad integrally mounted thereto is achieved through a simple structure, thereby reducing and simplifying the number of parts, and improving durability.

[0054] Fig. 5 illustrates a cross-sectional structure of a garage control device according to another embodiment of the present invention.

[0055] The embodiment illustrated in FIG. 5 differs from the embodiments illustrated in FIGS. 1 to 4 only in that the joint structure of the screw shaft (500) and the screw nut (600) is a ball screw structure. As illustrated in FIG. 5, according to another embodiment of the present invention, in order to assist longitudinal movement of the screw nut (600), the screw shaft (500) and the screw nut (600) are spaced apart from each other, and a plurality of rolling elements (not illustrated) may be interposed in the spaced apart space, i.e., between the screw shaft (500) and the screw nut (600).

[0056] According to one embodiment of the present invention, the driving member is a member that performs rolling motion between the screw shaft (500) and the screw nut (600), and the driving member may be formed as a ball member having a spherical shape. Accordingly, the garage control device (1) according to one embodiment of the present invention can assist the longitudinal relative movement between the screw shaft (500) and the screw nut (600) while generating less resistance by performing rolling motion of the driving member.

[0057] According to one embodiment of the present invention, a sealing boot (800) may be arranged between the first housing (320) and the spring pad (700) to seal the space between the first housing (320) and the spring pad (700). For example, the sealing boot (800) may be formed of a flexible bellows element, and may be made of a rubber material as an example.

[0058] As an example, a lower surface of the lower housing (324) of the first housing (320) may be formed with a rim (326) that protrudes downward along its outer periphery, and one end of the sealing boot (800) may be fixed to the rim (326).

[0059] In addition, the other end of the sealing boot (800) can be fixed by being interposed between the screw nut (600) and the spring pad (700). For more secure fixation of the sealing boot (800), a through hole (820) corresponding to the protrusion (710) of the spring pad (700) can be formed in the other end of the sealing boot (800). Accordingly, when the protrusion (710) of the spring pad (700) is coupled to the hole (620) of the screw nut (600), the protrusion (710) extends the through hole (820) of the sealing boot (800) and is coupled to the hole (620) of the screw nut (600), whereby the sealing boot (800) can be more securely fixed between the screw nut (600) and the spring pad (700).

[0060] In the above-described structure, the sealing boot (800) is disposed between the first housing (320) and the spring pad (700) to seal the space between the first housing (320) and the spring pad (700), so that the coil spring (900) is exposed to the outside, and all major components of the garage control device except the coil spring (900) can be sealed from the outside. For example, not only can moisture or foreign substances be prevented from penetrating into the gap between the screw shaft (500) and the screw nut (600), but also moisture or foreign substances can be prevented from penetrating into the gap between the screw shaft (500) and the lower housing (324) and having a negative effect on the screw shaft (500) and the gear (200). In particular, in the case of a conventional vehicle height adjustment device that applies a sealing member configured to include a plurality of parts such as a coil spring, a screw shaft, and a screw nut all inside, once moisture or foreign substances penetrate into the sealing member, the penetrated moisture or foreign substances have difficulty escaping outside the sealing member, so they remain inside the sealing member, which may increase the risk of failure of the vehicle height adjustment device. In contrast, according to one embodiment of the present invention, since the sealing boot (800) only seals the space between the first housing (320) and the spring pad (700), all parts that must be protected from the penetration of moisture or foreign substances can be sealed from the outside, so that the sealing performance can be improved compared to the conventional device.

[0061] Additionally, according to one embodiment of the present invention, for sealing, the garage control device (1) may further include a cover (40). The cover (40) is configured to cover at least a portion of the screw shaft (500), and as an example, at least a portion of the cover (40) may be interposed and fixed between the screw nut (600) and the spring pad (700).

[0062] FIG. 6 is an enlarged view of area A shown in FIG. 5. Referring to FIG. 6, the ratio of the length of the screw shaft to the length of the screw nut is described as follows. According to one embodiment of the present invention, when the vehicle is operated at a height adjustment of 40 mm, the screw nut (600) and the screw shaft (500) may be designed so that the ratio (L2 / L1) of the length (L1) of the screw nut (600) to the length (L2) of the screw shaft (500) is 2.3 or less. In addition, when the vehicle is operated at a height adjustment of 60 mm, the screw nut (600) and the screw shaft (500) may be designed so that the ratio (L2 / L1) of the length (L1) of the screw nut (600) to the length (L2) of the screw shaft (500) is 2.9 or less.

[0063] In addition, when the garage adjustment is 40 mm, the length (L1) of the screw nut (600) can be 35 mm. This is because, in order to support the screw axial load, the ball diameter is set to 5 mm based on the ball screw, and when 4 rows of balls are arranged, the length (L1) of the screw nut (600) must be 35 mm or more. In addition, when the ball diameter is set to 5 mm and 4 rows of balls are arranged, the width diameter (Dpw) between balls can be 34 mm.

[0064] For example, if the ratio (L2 / L1) of the length (L1) of the screw nut (600) and the length (L2) of the screw shaft (500) is 2.3 or more, and the length (L2) of the screw shaft (500) is 80 mm, the length (L1) of the screw nut (600) is reduced. At this time, one of the four ball circulation points is omitted, so that it is composed of three points, and accordingly, the axial support is reduced by 1 / 4, which may have a negative effect on strength and durability.

[0065]

[0066] Although the present invention has been described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as defined in the following claims. Furthermore, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention, and all technical ideas falling within the scope of the following claims and equivalents thereof should be construed as being included within the scope of the rights of the present invention.

Claims

1. A vehicle height adjustment device (1) that adjusts the height of the vehicle body. A first housing (320) that accommodates an electric motor (100) or a gear (200) rotated by the electric motor (100), A screw shaft (500) that is driven to rotate by the above motor (100) or the above gear (200), A non-rotating screw nut (600) configured to be movable in the longitudinal direction of the screw shaft (500) with respect to the screw shaft (500), A spring pad (700) that is integrally mounted on the screw nut (600) and configured to move together with the screw nut (600); Including a sealing boot (800) configured to seal the space between the first housing (320) and the spring pad (700). Garage control device.

2. In paragraph 1, The above garage adjustment device (1) further includes a spring mounted between the spring pad (700) and the lower arm, The above screw nut (600) is prevented from rotating around the screw shaft (500) by the spring and is allowed to move in the longitudinal direction of the screw shaft (500). Garage control device.

3. In paragraph 1, The above sealing boot (800) is composed of a flexible bellows element. Garage control device.

4. In paragraph 1, A screw shaft thread portion (510) is formed on the outer surface of the above screw shaft (500), On the inner surface of the screw nut (600), a screw nut thread portion (610) having a shape corresponding to the screw shaft thread portion (510) is formed. The above screw nut (600) is configured to be screw-connected to the screw shaft (500). Garage control device.

5. In paragraph 1, A plurality of driving bodies are further included between the screw nut (600) and the screw shaft (500), The above plurality of electric elements are configured to perform cloud motion to assist the longitudinal relative movement between the screw shaft (500) and the screw nut (600). Garage control device.

6. In paragraph 2, The above spring is a coil spring (900). Garage control device.

7. In paragraph 1, The electric motor (100) or the gear (200) rotated by the electric motor (100) and the first housing (320) containing the gear (200) inside are a top mount assembly fixed to the body side. The above first housing (320) includes an upper housing (322) and a lower housing (324), The upper portion of the screw shaft (500) is rotatably coupled to the first housing (320), On the lower surface of the lower housing (324), a border (326) is formed that protrudes downward along its outer circumference, One end of the above sealing boot (800) is fixed to the above frame (326), Garage control device.

8. In paragraph 1, The other end of the above sealing boot (800) is interposed and fixed between the screw nut (600) and the spring pad (700). Garage control device.

9. In paragraph 1, The motor (100) or the gear (200) rotated by the motor (100) and the first housing (320) containing the same are top mount assembly fixed to the body side. The above screw shaft (500), the above screw nut (600), and the above spring pad (700) are all configured to be suspended from the above top mount assembly. Garage control device.

10. In paragraph 1, At least one hole (620) is formed in the above screw nut (600), At least one protrusion (710 / 720) is formed on the upper surface of the spring pad (700) to be inserted into at least one hole (620). Garage control device.

11. In paragraph 1, The above garage control device (1) further includes a cover (40), The above cover (40) is configured to cover at least a portion of the screw shaft (500), The above cover (40) is fixed by being interposed between at least a portion of the screw nut (600) and the spring pad (700). Garage control device.

12. In paragraph 1, As the screw shaft (500) rotates, the screw nut (600) is configured to move up and down in the longitudinal direction with respect to the screw shaft (500) to adjust the height of the vehicle body. Garage control device.

13. In paragraph 1, The above first housing (320) accommodates a gear (200) inside, The above garage control device (1) further includes a second housing (340) that accommodates a motor (100) and a drive shaft (10), The second housing (340) is configured to be suspended from the first housing (320). Garage control device.

14. In paragraph 5, When the garage adjustment is 40 mm, the ratio (L2 / L1) of the length of the screw nut (600) and the length of the screw shaft (L2) is formed so that the screw nut (600) and the screw shaft (500) are 2.3 or less. Garage control device.

15. In paragraph 5, When the garage adjustment is 60 mm, the ratio (L2 / L1) of the length of the screw nut (600) and the length of the screw shaft (L2) is formed so that the screw nut (600) and the screw shaft (500) are 2.9 or less. Garage control device.

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