CN212572288U - Drive device - Google Patents

Abstract

The utility model provides a driving device, it can follow the motor to the movable part steadily transmit power and compact. The drive device has: a frame having a pair of hooks engageable with the guide shaft; a lead screw rotatably supported by the frame; a motor connected to the screw shaft to rotate the screw shaft; a nut engaged with the lead screw; and a movable member. The movable member has a nut housing portion for housing the nut, a slide portion slidable on the guide shaft, and a mounting portion to which the camera unit is mounted. The upper outer surface of the nut has a plurality of upper projections projecting in the Z direction, and the lower outer surface has a plurality of lower projections projecting in the Z direction. The inner surface of the upper side wall of the nut accommodating portion is configured to contact with the upper protrusion, and the inner surface of the lower side wall is configured to contact with the lower protrusion.

Description

Drive device

Technical Field

The present invention relates to a driving device, and more particularly to a driving device for moving a driving object in an axial direction with respect to a reference member.

Background

In recent years, electronic devices such as laser irradiation type disk devices and smart phones are increasingly equipped with a mechanism (driving device) for moving a lens, a camera, and the like as needed. For example, in a smartphone having a camera, a function of taking out or putting in the camera from or to the smartphone main body is sometimes added. In order to move such a driving object such as a lens or a camera, for example, a driving device using a lead screw is considered (for example, see patent document 1). In a driving device using such a lead screw, a driving object such as a lens or a camera is fixed to a movable portion attached to the lead screw, and the driving object is moved in an axial direction by rotating the lead screw by a motor.

However, in such a driving device, when an assembly error or the like occurs between the components, a force may be transmitted from the screw rod to the movable portion in a biased manner. In this case, the transmission of force to the movable portion becomes unstable, and the movement of the movable member also becomes unstable. Therefore, a driving device capable of stably transmitting force from a motor to a movable member is required. Further, since the driving device needs to be stored in a limited space in the electronic apparatus, the driving device is also required to be downsized.

Patent document 1: japanese patent laid-open publication No. 2018-137958

SUMMERY OF THE UTILITY MODEL

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a compact drive device capable of stably transmitting force from a motor to a movable member.

According to an aspect of the present invention, there is provided a compact drive device capable of stably transmitting a force from a motor to a movable member. The driving device is used for moving the driving object relative to the reference component along the axial direction. The drive device includes: a frame having a pair of hooks engageable with the guide shaft extending in the axial direction and a fixing portion fixed to the reference member; a lead screw extending in the axial direction and rotatably supported by the frame; a motor coupled to the screw shaft to rotate the screw shaft; a nut engaged with the screw shaft and having a 1 st outer surface and a 2 nd outer surface located on opposite sides of the screw shaft in the axial direction; and a movable member. The movable member has a nut receiving portion for receiving the nut, a sliding portion slidable on the guide shaft, and an attachment portion to which the driving object is attached. The nut accommodating portion includes: a 1 st inner surface opposite the 1 st outer surface of the nut; and a 2 nd inner surface opposite the 2 nd outer surface of the nut. One of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion has a plurality of 1 st protrusions protruding in the axial direction. The other of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion is configured to contact the plurality of 1 st protrusions.

In such a configuration, the hook portion of the frame is engaged with the guide shaft, so that the distance between the screw and the guide shaft can be reduced, and the overall size of the drive device can be reduced. Further, since the plurality of 1 st protrusions provided on one of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion are in contact with the other of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion, when the nut moves in the axial direction, a force in the axial direction always acts on the nut receiving portion via the 1 st protrusions. Therefore, even if an assembly error or the like occurs between the members, the force is not transmitted from the nut to the movable member, and the force can be stably transmitted to the movable member via the 1 st projection. As a result, the movement of the movable member is stabilized.

In order to further stabilize the transmission of force from the nut to the movable member, it is preferable that the plurality of 1 st projections are formed at positions symmetrical with respect to the central axis of the screw shaft.

One of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut receiving portion may have a plurality of 2 nd protrusions protruding in the axial direction, and the other of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut receiving portion may be configured to contact the plurality of 2 nd protrusions. In this case, since the plurality of 2 nd protrusions provided on one of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut accommodating portion come into contact with the other of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut accommodating portion, when the nut moves in the axial direction, a force in the axial direction always acts on the nut accommodating portion via the 2 nd protrusions. Therefore, even if an assembly error or the like occurs between the nut and the movable member, the force is not transmitted from the nut to the movable member in a biased manner, and the force can be stably transmitted to the movable member via the 2 nd projection. As a result, the movement of the movable member is further stabilized.

In order to further stabilize the transmission of force from the nut to the movable member, it is preferable that the plurality of 2 nd projections are formed at positions symmetrical with respect to the central axis of the screw shaft.

Preferably, the pair of hook portions are disposed so as to sandwich the movable member in the axial direction. By disposing the pair of hook portions so as to sandwich the movable member in the axial direction, the movable member can be stably slid inside the frame.

According to the present invention, the hook portion of the frame is engaged with the guide shaft, so that the interval between the lead screw and the guide shaft can be narrowed, and the entire size of the drive device can be made compact. Further, since the plurality of 1 st protrusions provided on one of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion are in contact with the other of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion, when the nut moves in the axial direction, a force in the axial direction always acts on the nut receiving portion via the 1 st protrusions. Therefore, even if an assembly error or the like occurs between the nut and the movable member, the force is not transmitted from the nut to the movable member in a biased manner, and the transmission of the force from the nut to the movable member can be stabilized.

Drawings

Fig. 1 is a front view showing a driving device according to an embodiment of the present invention together with a driving object.

Fig. 2 is an exploded perspective view of the driving device of fig. 1.

Fig. 3 is a perspective view showing a relationship among a screw, a nut, a movable portion, and a guide shaft in the driving device of fig. 1.

Fig. 4 is a perspective view showing a movable portion in the driving device of fig. 1.

Fig. 5 is a perspective view illustrating a nut in the driving device of fig. 1.

Description of the reference symbols

1: a drive device; 2: a camera unit; 3: a smartphone main body; 10: a frame; 11: an upper flange portion; 12: a lower flange portion; 13: a fixed part; 14: an upper side hook portion; 15: a lower hook portion; 16: a back plate portion; 20: a stepping motor; 22: a gear case; 30: a lead screw; 31: an upper side bearing; 32: a lower bearing; 33: a spur gear; 40: a nut; 41: an upper side projection (1 st projection or 2 nd projection); 42: a lower side protrusion (2 nd protrusion or 1 st protrusion); 45: a nut body; 45A: an upper outer surface (1 st outer surface or 2 nd outer surface); 45B: a lower outer surface (2 nd outer surface or 1 st outer surface); 46: a clamping hole; 50: a movable member; 51: a nut receiving portion; 52: a sliding part; 53: an installation part; 55: an upper sidewall; 55B: an inner surface (1 st inner surface or 2 nd inner surface); 56: a lower sidewall; 56B: an inner surface (2 nd inner surface or 1 st inner surface); 57: a front side wall; 60: a guide shaft.

Detailed Description

Hereinafter, an embodiment of the driving device of the present invention will be described in detail with reference to fig. 1 to 5. In fig. 1 to 5, the same or corresponding components are denoted by the same reference numerals, and redundant description thereof is omitted. In fig. 1 to 5, the scale and size of each component may be exaggerated, and some components may be omitted.

Fig. 1 is a front view showing a driving device 1 according to an embodiment of the present invention together with a camera unit 2 as a driving object. The driving device 1 of the present embodiment is provided inside the smartphone body 3, for example, and can move the camera unit 2 including an imaging lens and an imaging element in the Z direction with respect to the smartphone body 3 as a reference member. For example, the drive device 1 can move the camera unit 2 in the + Z direction to protrude from the smartphone body 3 during image capturing, and move the camera unit 2 in the-Z direction to be housed inside the smartphone body 3 after image capturing is completed. Fig. 1 shows a state in which the camera unit 2 is not used, and the camera unit 2 is housed inside the smartphone body 3 in this state. In the present embodiment, for convenience, the + Z direction in fig. 1 is referred to as "up" or "upper", and the-Z direction is referred to as "down" or "lower".

As shown in fig. 1, the drive device 1 includes a frame 10 fixed to the smartphone body 3, a stepping motor 20 attached to the frame 10, a gear box 22 attached to the stepping motor 20, a lead screw 30 extending in the Z direction (axial direction), and a nut 40 engaged with the lead screw 30. A thread is formed on the outer peripheral surface of the screw shaft 30, but the thread of the screw shaft 30 is not shown for easy understanding. The smartphone body 3 is provided with a guide shaft 60 extending in the Z direction, and the guide shaft 60 and the lead screw 30 extend in parallel in the Z direction at adjacent positions. The drive device 1 further has a movable member 50 slidable on the guide shaft 60 in the Z direction.

Fig. 2 is an exploded perspective view of the drive device 1. As shown in fig. 1 and 2, the frame 10 includes an upper flange portion 11, a lower flange portion 12, a fixing portion 13 formed with a screw hole 13A into which a fixing screw is inserted, an upper hook portion 14 provided at an end portion of the upper flange portion 11, a lower hook portion 15 provided at an end portion of the lower flange portion 12, and a back plate portion 12 extending between the upper flange portion 11 and the lower flange portion 12. The frame 10 is fixed to the smartphone body 3 by inserting screws (not shown) through the screw holes 13A of the fixing portion 13 and screwing the screws into the smartphone body 3. These fixing portions 13 are provided so as to extend from the upper flange portion 11 and the lower flange portion 12, respectively. As shown in fig. 2, the upper hook 14 and the lower hook 15 of the frame 10 are engaged with the guide shaft 60, respectively. The gear case 22 is fixed to the lower flange portion 12 of the frame 10 by screws 23.

The screw shaft 30 is attached to the upper flange portion 11 and the lower flange portion 12 of the frame 10 via an upper bearing 31 and a lower bearing 32, respectively, and is rotatably supported with respect to the frame 10. Fig. 3 is a perspective view showing a relationship of the lead screw 30, the nut 40, the movable member 50, and the guide shaft 60 of fig. 1, and a part of the movable member 50 is cut away for easy understanding. As shown in fig. 3, a spur gear 33 is attached to the screw 30, and the spur gear 33 is housed in the gear case 22.

In addition to the spur gear 33 of the lead screw 30, a planetary gear mechanism (not shown) coupled to an output shaft of the stepping motor 20 is housed in the gear box 22. The rotation of the stepping motor 20 is decelerated by the planetary gear mechanism. The planetary gear mechanism is also coupled to a spur gear 33 attached to the lead screw 30, and the lead screw 30 is coupled to the output shaft of the stepping motor 20 via the spur gear 33 and the planetary gear mechanism. Therefore, when the stepping motor 20 is driven, the rotation of the output shaft of the stepping motor 20 is transmitted to the lead screw 30 via the planetary gear mechanism and the spur gear 33, and the lead screw 30 rotates.

Fig. 4 is a perspective view of the movable member 50. As shown in fig. 2 and 4, the movable member 50 includes a nut housing 51 that houses the nut 40, a slide portion 52 that forms a shaft hole 52A through which the guide shaft 60 is inserted, and a mounting portion 53 to which the camera unit 2 is mounted. The slide portion 52 slides on the guide shaft 60 in the Z direction while being guided by the guide shaft 60 inserted through the shaft hole 52A. The camera unit 2 mounted on the mounting portion 53 of the movable member 50 moves in the Z direction together with the movable member 50.

Fig. 5 is a perspective view of the nut 40. As shown in fig. 5, the nut 40 has a substantially rectangular parallelepiped nut body 45, and includes an upper protrusion 41 protruding upward (+ Z direction) from an upper outer surface 45A of the nut body 45, and a lower protrusion 42 protruding downward (-Z direction) from a lower outer surface 45B of the nut body 45. An engagement hole 46 penetrating the nut body 45 in the Z direction is formed in the center of the nut body 45, and a thread groove (not shown) engaging with a thread of the screw shaft 30 is formed in an inner peripheral surface of the engagement hole 46. In the present embodiment, two upper projections 41 and two lower projections 42 are formed so as to face each other in the X direction with the center of the engagement hole 46 therebetween. As described later, the upper projection 41 and the lower projection 42 are preferably formed at positions symmetrical with respect to the center axis of the engagement hole 46, that is, the center axis of the screw 30.

As shown in fig. 4, the nut accommodating portion 51 of the movable member 50 includes an upper side wall 55, a lower side wall 56, and a front side wall 57 connecting the upper side wall 55 and the lower side wall 56, and accommodates the nut 40 in a space S defined by the upper side wall 55, the lower side wall 56, and the front side wall 57. Further, notches 55A and 56A for passing the screw 30 are formed in the upper side wall 55 and the lower side wall 56, respectively.

As shown in fig. 3, the upper projection 41 of the nut 40 contacts the inner surface 55B of the upper side wall 55 of the nut accommodating portion 51 of the movable member 50, and the lower projection 42 of the nut 40 contacts the inner surface 56B of the lower side wall 56 of the nut accommodating portion 51 of the movable member 50. In the Y direction, the nut body 45 of the nut 40 is held between the front side wall 57 of the nut accommodating portion 51 of the movable member 50 and the back plate portion 16 of the frame 10.

In such a configuration, when the stepping motor 20 is driven, the rotation of the output shaft of the stepping motor 20 is transmitted to the lead screw 30 via the planetary gear mechanism in the gear box 22 and the spur gear 33, and the lead screw 30 rotates. When the screw shaft 30 rotates, the nut 40 engaged with the thread of the screw shaft 30 also rotates, but the nut 40 cannot rotate because the nut main body 45 of the nut 40 is held between the front side wall 57 of the nut housing portion 51 of the movable member 50 and the back plate portion 16 of the frame 10. Therefore, the nut 40 moves in the Z direction by engaging with the thread of the rotating screw 30.

Here, as described above, since the upper projection 41 of the nut 40 contacts the inner surface 55B of the upper side wall 55 of the nut accommodating portion 51, when the nut 40 moves in the + Z direction, a force in the + Z direction always acts on the inner surface 55B of the nut accommodating portion 51 through the upper projection 41 of the nut 40. Further, since the lower projection 42 of the nut 40 contacts the inner surface 56B of the lower side wall 56 of the nut accommodating portion 51, when the nut 40 moves in the-Z direction, the force in the-Z direction always acts on the inner surface 56B of the nut accommodating portion 51 through the lower projection 42 of the nut 40. Therefore, even if an assembly error or the like occurs between the nut 40 and the movable member 50, the force is not transmitted from the nut 40 to the movable member 50 in a biased manner, and the force can be stably transmitted from the nut 40 to the movable member 50 via the upper protrusion 41 or the lower protrusion 42. As a result, the movement of the movable member 50 is stabilized.

When the stepping motor 20 is driven in this way, the lead screw 30 rotates, and the nut 40 moves in the Z direction, and along with this, the movable member 50 and the camera unit 2 attached to the attachment portion 53 of the movable member 50 also move in the Z direction.

In the present embodiment, the upper hook 14 and the lower hook 15 of the frame 10 are engaged with the guide shaft 60, so that the distance between the screw shaft 30 and the guide shaft 60 can be reduced, and the overall size of the drive device 1 can be made compact. In the present embodiment, since the upper hook portion 14 and the lower hook portion 15 are disposed so as to sandwich the movable member 50 in the Z direction, the movable member 50 can be stably slid inside the frame 10.

Here, in order to further stabilize the transmission of the force from the nut 40 to the movable member 50, the upper protrusion 41 and the lower protrusion 42 of the nut 40 are preferably formed at positions symmetrical with respect to the central axis of the screw shaft 30. The number of the upper projections 41 of the nut 40 is not limited to 2, and may be 3 or more. The number of the lower projections 42 of the nut 40 is not limited to 2, and may be 3 or more. In this case, it is also preferable that 3 or more upper protrusions 41 and/or 3 or more lower protrusions 42 be formed at positions symmetrical with respect to the central axis of the screw shaft 30.

Instead of forming the upper projection 41 on the upper outer surface 45A of the nut 40, an upper projection may be formed on the inner surface 55B of the upper wall 55 of the movable member 50 so as to be in contact with the upper outer surface 45A of the nut 40. In addition to or instead of the lower protrusion 42 formed on the lower outer surface 45B of the nut 40, a lower protrusion may be formed on the inner surface 56B of the lower wall 56 of the movable member 50 so as to be in contact with the lower outer surface 45B of the nut 40. In addition, only one of the upper projection 41 and the lower projection 42 may be formed.

In the above embodiment, the example in which the stepping motor 20 is used to rotate the lead screw 30 has been described, but the motor for rotating the lead screw 30 is not limited to the stepping motor. However, in order to accurately control the amount of movement of the camera unit 2, a stepping motor is preferably used as the motor for rotating the lead screw 30.

In the above-described embodiment, the example in which the planetary gear mechanism is used as the gear mechanism that decelerates the rotation of the output shaft of the stepping motor 20 has been described, but any gear mechanism may be used as the gear mechanism that decelerates the rotation of the output shaft of the stepping motor 20.

While the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and it goes without saying that the present invention can be implemented in various different forms within the scope of the technical idea thereof.

Claims (7)

1. A drive device for moving a drive target in an axial direction with respect to a reference member,

the driving device comprises:

a frame having a pair of hooks engageable with the guide shaft extending in the axial direction and a fixing portion fixed to the reference member;

a lead screw extending in the axial direction and rotatably supported by the frame;

a motor coupled to the screw shaft to rotate the screw shaft;

a nut engaged with the screw shaft and having a 1 st outer surface and a 2 nd outer surface located on opposite sides of the screw shaft in the axial direction; and

a movable member having a nut receiving portion for receiving the nut, a sliding portion slidable on the guide shaft, and an attachment portion to which the driving object is attached,

the nut accommodating portion includes:

a 1 st inner surface opposite the 1 st outer surface of the nut; and

a 2 nd inner surface opposite the 2 nd outer surface of the nut,

one of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion has a plurality of 1 st protrusions protruding in the axial direction,

the other of the 1 st outer surface of the nut and the 1 st inner surface of the nut receiving portion is configured to contact the plurality of 1 st protrusions.

2. The drive device according to claim 1,

the 1 st projections are formed at positions symmetrical with respect to a central axis of the lead screw.

3. The drive device according to claim 1,

one of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut receiving portion has a plurality of 2 nd protrusions protruding in the axial direction,

the other of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut receiving portion is configured to contact the plurality of 2 nd protrusions.

4. The drive device according to claim 2,

one of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut receiving portion has a plurality of 2 nd protrusions protruding in the axial direction,

the other of the 2 nd outer surface of the nut and the 2 nd inner surface of the nut receiving portion is configured to contact the plurality of 2 nd protrusions.

5. The drive device according to claim 3,

the plurality of 2 nd protrusions are formed at positions symmetrical with respect to a central axis of the lead screw.

6. The drive device according to claim 4,

the plurality of 2 nd protrusions are formed at positions symmetrical with respect to a central axis of the lead screw.

7. The drive device according to any one of claims 1 to 6,

the pair of hook portions are disposed so as to sandwich the movable member in the axial direction.

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