JPH07145857A - Driving force transmission device - Google Patents

Abstract

PURPOSE:To perform shifting of drive parts of two systems requiring forward and reversing through simple structure by a method wherein a first rotation member moved in one of the axial directions of a solar gear and rotated integrally with a carrier is locked and a second rotation member moved in other and rotated integrally with an internal tooth gear is locked. CONSTITUTION:Slit discs 3a and 3b are arranged on a carrier output shaft 23b and an internal output shaft 24a and a resilient plate 51 is disposed between the two discs. The bent piece 51a of the resilient plate 51 is engaged with the slit of the outer peripheral part of the slit disc 3a when a coupler 4 is protruded upward from a mount 8 surface, and rotation thereof is locked. The bent piece 51b is present in a position where it is not engaged with the slit. When the coupler 4 is pushed in to the same level as that of the mount 8 surface, the bent piece 51b is lowered to a position where it is engaged with the slip of the outer peripheral part of the slit disc 3b, and the bent piece 51a is not engaged with the slit. Thus, a driven part itself is selected and drive of the driven parts of two systems needing forward and reversing is switcheable through simple structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force transmission device, and more specifically, one motor output is switched to a two-system driving system by using a planetary gear mechanism. The present invention relates to a driving force transmission device that can be used.

[0002]

2. Description of the Related Art In recent years, in cameras and the like that use a roll film having a width of 35 mm, automation in taking photographs has been advanced. For example, various automations such as diaphragm drive for automatic exposure and lens drive for autofocus are being performed, and the miniaturization of camera bodies is also progressing.
This compatibility is an essential requirement for camera design. For such automation, it is quite natural to use one motor built in the camera body as a drive source for a plurality of operating mechanisms. Therefore, the transmission of the motor output is appropriately switched to each driven mechanism,
A driving force transmission device for transmitting to each driven mechanism is required. As such a driving force transmission device, there has been a device using an electromagnetic clutch or the like from the related art.
There is a camera drive device disclosed in Japanese Patent No. 170906. This is because when switching the driving force, the switching gear is moved axially by the electromagnetic force so that the driving force from the motor is transmitted to either one of the driven parts of the two systems. is there.

Further, as means for switching the transmission of the driving force of the motor without using electricity, for example, Japanese Utility Model 4-
There is an automatic clutch mechanism for a camera disclosed in Japanese Patent No. 17933, in which a clutch portion that transmits a driving force to a driven portion moves in an axial direction according to a rotation direction of a motor, and a driving force to the driven portion is provided. The transmission of is switched.

[0004]

However, since the means disclosed in the above-mentioned Japanese Patent Laid-Open No. 3-170906 is operated electrically, it is judged to select the driven source before driving the motor. It is necessary to switch the transmission of the driving force by the circuit, which causes a problem that a time lag occurs before the driving is started. Further, when a failure occurs in the determination circuit, the driving force may be erroneously transmitted to the driven portion side. In addition, when switching the driving force, electricity is required in addition to the driving motor, so that power consumption is expedited. Further, at a low temperature, the current value of the power source may decrease, which may make it impossible to perform the original purpose of switching the driving force transmission.

On the other hand, since the means disclosed in Japanese Utility Model Publication No. 4-17933 is not an electrical switching means, the above-mentioned problems do not occur. Since the transmission of the driving force to the driven part is switched depending on the rotation direction of the reverse rotation and the reverse rotation, it cannot be applied when both the forward and reverse driving forces are required for each driven part. There are drawbacks.

It is an object of the present invention to perform drive switching to a driven part of two systems, which requires rotational driving force in both directions of forward and reverse rotation, without using electric means and with a simpler structure. A drive force transmission device is provided.

[0007]

A driving force transmission device according to the present invention includes a sun gear that is normally and reversely rotated by the output of a motor, a planetary gear that is constantly meshed with the sun gear, and the planetary gear that is rotatable. And a carrier rotatably supported coaxially with the sun gear, and internal teeth with which the planet gear always meshes on the outer periphery of the revolution trajectory of the planet gear, and coaxial with the sun gear. An internal gear that is rotatably supported above, a first driven mechanism that is connected to the carrier, a second driven mechanism that is connected to the internal gear, and the carrier and an axis around A first rotating member that rotates integrally, and rotates integrally around the internal gear and the shaft,
A second rotating member that is spaced apart in the axial direction of the sun gear with respect to the first rotating member, and the first rotating member and the second rotating member, arranged between the axial direction, By being moved in one direction along the axial direction of the sun gear, the rotation of the first rotating member is locked by engaging with the first rotating member, and by moving to the other, the first rotating member is locked. And a rotation locking member that locks the rotation of the second rotation member by engaging with the second rotation member.

[0008]

When the rotation locking member is moved to one side along the axial direction of the sun gear, the rotation locking member is engaged with the first rotation member to lock the rotation of the first rotation member, and the internal gear The driving force of the motor is transmitted to the second driven mechanism coupled to the second driven mechanism, and the second rotation member is engaged with the second rotation member by moving the rotation locking member to the other side. Lock the rotation of the member,
The driving force of the motor is transmitted to the first driven mechanism connected to the carrier.

[0009]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a perspective view of a driving force transmission device showing an embodiment of the present invention, and FIG. 2 is an enlarged longitudinal sectional view of an essential part showing an internal structure of a planetary gearbox used in the driving force transmission device. . In the drive force transmission device of this embodiment, the planetary gear mechanism in the planetary gearbox reduces the drive output of the motor, and the transmission direction of the drive force is switched to either one of the two driven mechanisms. It was done. In addition,
The following embodiments describe the case where the driving force transmission device according to the present invention is applied to a camera.

As shown in FIGS. 1 and 2, the planetary gearbox 2 is composed of an outer casing 25 having a short tubular shape, and a motor 1 is arranged below the outer casing 25. A bearing 26 is fixed to the upper opening of the outer case 25 with screws or the like, and the outer case 25 is fixed to the casing 1b of the motor 1 with screws or the like.

The motor output shaft 1a projecting upward from the central portion of the motor 1 is projected upward from the central hole 25a of the bottom wall of the outer case 25 of the planetary gearbox 2 into the outer case 25. Has been inserted into. A pinion gear 21, which is a sun gear of a planetary gear mechanism, is fitted on the motor output shaft 1a.

A carrier output shaft 23b extending from a carrier 23 for supporting the planetary gear 22 is disposed coaxially with the motor output shaft 1a.
On the lower side of the carrier 23, three planetary gear shafts 23a for rotatably supporting the three planetary gears 22 that are always meshed with the pinion gear 21, respectively,
The planetary gears 22 are arranged along the outer circumference of the pinion gear 21 at equal intervals, and the planetary gears 22 are rotatably supported by the planetary gear shafts 23a.

A slit disk 3a, which is a first rotating member, is integrally formed on the upper end of the carrier output shaft 23b. The slit disc 3a has a large number of radial slits formed on the outer periphery thereof and rotates coaxially with the carrier output shaft 23b. Further, the slit disk 3 of the carrier output shaft 23b
A toothed portion 23c is formed on the outer peripheral portion of the lower part of a, and the toothed portion 23c is connected to the first driven mechanism,
The timing belt 6a for transmitting the driving force of the motor 1 is meshed with the timing belt 6a.

On the other hand, the outer periphery of each planetary gear 22 has an inner tooth 24d on its inner peripheral surface which meshes with each planetary gear 22.
A short cylinder-shaped internal gear 24 in which is formed is disposed, and a flange 24 b is provided on the upper end surface of the gear 24.
Is integrally formed, and an internal output shaft 24a, which is a pipe shaft rotatably fitted in the middle of the carrier output shaft 23b, is integrally formed at the center of the flange 24b.

At the upper end of the internal output shaft 24a, a slit disk 3b as a second rotating member is integrally formed. The slit disc 3b is formed in the same shape and size as the slit disc 3a. That is, the slit disc 3b is separated from the slit disc 3a provided on the carrier output shaft 23b in the axial direction of the pinion gear 21, and the slit disc 3a is provided.
Similarly to the above, a large number of radial slits are formed in the outer peripheral portion. Then, in the outer peripheral portion of the upper end portion of the internal output shaft 24a, similar to the carrier output shaft 23b described above,
A tooth profile 24c is formed, and the tooth profile 24c has
A timing belt 6b that is connected to the second driven mechanism and transmits the driving force of the motor 1 meshes with the second driven mechanism. The internal gear 24 is pivotally supported by a bearing 26.

In the planetary gear mechanism portion such as the planetary gear 22 described above, all the constituent members of the planetary gear mechanism are provided in the cylinder formed by the outer case 25 and the bearing 26, that is, in the planetary gear box 2. The rotation locking of the first or second rotary member (the slit discs 3a, 3b), which is provided and is arranged on either of the carrier output shaft 23b and the internal output shaft 24a, will be described later. By being locked by the means, the driving force is switched and transmitted to the other output shaft having the rotating member which is not locked at this time.

The other end of the timing belt 6b meshing with the outer periphery of the internal output shaft 24a of the gear box 2 is connected to the pulley 7 which is the second driven mechanism, as shown in FIG. . An oval through hole is provided at the center of rotation of the pulley 7, and the central axis of the coupler 4 forming the driving force transmission shaft is provided so as to penetrate therethrough. Since the shaft portion on the lower side of the coupler 4 has the same shape as an oval through hole provided at the rotation center of the pulley 7, the coupler 4 rotates integrally with the pulley 7. It is supposed to do.

The upper end of the coupler 4 is inserted into a through hole 8a formed in a mount 8 for mounting an interchangeable lens for photographing on a camera body (not shown), and is projected upward by the urging force of a spring. Has been pressed to. Therefore, in the state where the interchangeable lens for photographing is not attached to the body mount 8, as shown in FIG.
The tip portion of the coupler 4 is in a state of protruding from the surface of the mount 8. Further, the shape of the tip portion 4a of the coupler 4 is such that it is disengaged from the coupler 9a provided on the lens side mount 9b of the autofocus (AF) lens 9 shown in FIG. Since the coupler 9a has a shape having a slit-shaped slot in the center of the end face of the axis of the short cylinder, the tip portion 4a of the coupler 4 has a plate-like protruding shape that fits into and disengages from it.

As shown in FIG. 1, the elastic plate 51, which is a rotary locking member for locking the rotation of the slit disks 3a, 3b so as to be sandwiched between the coupler 4 and the pulley 7. Is integrally provided with the collar 5 fitted to the coupler 4, and the tip of the elastic body 51 is arranged between the slits of the slit disks 3a and 3b.
As shown in FIG. 5, the elastic plate 51 has its tip portion divided into two forks, and has a bent piece 51a bent upward at a right angle and a bent piece 51a bent downward at a right angle. It has bent pieces 51b, and each tip is formed in a mountain shape. The collar 5 is provided on the upper surface of the elastic plate 51 near the base end. The collar 5 is fixed to the coupler 4 in the axial direction (thrust direction) and rotatably in the rotation direction (radial direction). Rotation is restricted by guide shafts 60 and 61 that are supported by the body.

The elastic plate 51 thus constructed is
The carrier output shaft 23b and the internal output shaft 24
By being moved upward along the axial direction of a, the slit disc 3a and the bent piece 51a of the elastic plate 51 are engaged with each other to lock the rotation of the slit disc 3a, and When the elastic plate 51 is moved downward, the slit disc 3b and the bent piece 51b of the elastic plate 51 are engaged with each other to lock the rotation of the slit disc 3b. .

That is, as described above, the slit discs 3a and 3b are provided on the carrier output shaft 23b and the internal output shaft 24a, respectively, so that they are sandwiched between the two discs. The elastic plate 51 is arranged. The bent piece 51a of the elastic plate 51 engages with the slit on the outer peripheral portion of the slit disc 3a of the carrier output shaft 23b when the coupler 4 projects upward from the surface of the mount 8, and the slit disc Lock the rotation of 3a. At this time, since the other bent piece 51b has a sufficient space between the other bent piece 51b and the slit on the outer peripheral portion of the slit disk 3b on the side of the internal output shaft 24a, it is in a position where it does not engage with the slit.

When the coupler 4 is pushed into the same surface as the surface of the mount 8, the bent piece 51b of the elastic plate 51 has the slit disk 3 of the internal output shaft 24a.
b to the position where it engages with the slit on the outer peripheral portion, and the other bent piece 51a has a sufficient space between it and the slit on the outer peripheral portion of the slit disk 3a of the carrier output shaft 23b. Does not engage. Since the positional relationship between the slit discs 3a and 3b and the bent pieces 51a and 51b of the elastic plate 51 is set as described above, the vertical displacement of the coupler 4 and the slit discs 3a, There is a stipulation for the interval of 3b and the height of the bent pieces 51a, 51b.

On the other hand, to the other end of the timing belt 6a meshing with the outer periphery of the carrier output shaft 23b, a drive system of a mechanism for narrowing down the taking lens which is the first driven mechanism is connected. This first driven mechanism section is
Manual focus (MF) shown in FIGS.
The aperture lever 10a provided on the lens 10 for use, and when the aperture lever 10a is rotated, the above M
A diaphragm blade (not shown) of the F lens 10 is designed to be narrowed down by a diaphragm ring 10c of the MF lens 10 to a manually set diaphragm aperture position.

The transmission switching operation of the driving force of the motor in the driving force transmitting device for a camera according to the above-described embodiment will be described below with reference to FIGS. 3, 4, 6 and 7. FIGS. 3A and 3B are views showing an autofocus (AF) lens 9 which is an interchangeable lens for photographing of a camera. In this embodiment, the lens 9 is the same.
The coupler 9a constitutes a second driven mechanism. As mentioned above, the coupler 4 on the camera body side (see FIG. 1)
By coupling the coupler 9a on the AF lens 9 side shown in FIG. 3 (B) to rotate the coupler 4 on the camera body side, the optical system in the AF lens 9 is connected via the coupler 9a. The focus is adjusted by moving. At this time, the motor 1 is driven from the AF circuit by the signal generated by the AF sensor (not shown) on the camera body side.
The optical system in the F lens 9 moves, the driving of the motor 1 stops at the focal point, and the rotation of the coupler 4 also stops.

When the AF lens 9 that operates in this manner is mounted on the mount 8 on the camera body side, as shown in FIG.
As shown in FIG. 3, the coupler 4 on the camera body side and the coupler 9a on the AF lens 9 side are connected to each other, and
Protrudes toward the AF lens 9 side from the body-side mount 8 surface. At this time, the bending piece 51a of the elastic plate 51 is
As described above, the slit disk 3 of the carrier output shaft 23b
Enter the slit of a.

Since the slits of the slit disk 3a have a fine pitch, the elastic plate 51 is highly established.
The bent piece 51a of is engaged with the slit. Even when the bent piece 51a cannot be engaged with the slit, the slit disc 3a is pressed by the elastic pressing force of the elastic plate 51.

When the motor 1 is rotated in order to drive the lens of the AF lens 9 in such an engaged state, when the bent piece 51a is engaged with the slit of the slit disc 3a. Since the rotation of the slit disc 3a is reliably locked, the internal output shaft 24a obtains a driving force. On the other hand, when the motor 1 is rotated when the bent piece 51a is not engaged with the slit of the slit disk 3a, the tip of the bent piece 51a and the slit disk 3a are rotated.
The slit disc 3a rotates due to the contact frictional force with a,
When the slit and the bent piece 51a match, the bent piece 5
1a engages with the slit of the slit disc 3a, the slit disc 3a is securely locked, and the internal output shaft 24a
Will get the driving force. Therefore, in any case, the internal output shaft 24a obtains the driving force.

The driving force of the internal output shaft 24a is applied to the pulley 7 via the timing belt 6b.
Since the pulley 7 and the coupler 4 are integrally rotated as described above, when the coupler 4 is rotated, the coupler 9a on the AF lens 9 side engaged with the coupler 4 is also rotated, and The optical system of the AF lens 9 is moved for focusing, and focus adjustment is performed.

On the other hand, FIGS. 4A and 4B are views showing the lens 10 for manual focusing (MF), and in this embodiment, the diaphragm lever 10a of the lens 10 is shown.
Constitutes the first driven mechanism. The MF lens 10 has a diaphragm lever 10a that moves in an arc shape along the circumference in the middle of the mount surface 10b. The diaphragm lever 10a is always biased by a spring (not shown) provided in the MF lens 10, and when the diaphragm lever 10a is operated against the biasing force,
The diaphragm blades provided in the MF lens 10 are
A diaphragm ring 1 arranged on the exterior of the MF lens 10.
The aperture is set to 0c. The diaphragm blades are returned to the open position when the diaphragm lever 10a is returned by the urging force of the spring.

When the MF lens 10 that operates in this manner is mounted on the mount 8 on the camera body side, as shown in FIG.
As shown in, the tip of the coupler 4 on the body side contacts the mount 10b surface of the MF lens 10. At this time,
The bent piece 51b of the elastic plate 51 moves to a position where it enters the slit of the slit disc 3b of the internal output shaft 24a as described above. Then, when the motor 1 is rotated, the same operation as when the AF lens 9 is mounted is performed, and in this case, the carrier output shaft 23a obtains the driving force. That is, the tip of the bent piece 51b of the elastic plate 51 and the slit of the slit disk 3b are aligned with each other, the slit disk 3b is securely locked, and the carrier output shaft 23a obtains a driving force.

The driving force of the carrier output shaft 23a is
As described above, it is transmitted to the diaphragm drive mechanism (not shown) that drives the diaphragm lever 10a of the MF lens 10 via the timing belt 6a. Then, a diaphragm lever (not shown) on the camera body side rotates the diaphragm lever 10a on the MF lens 10 side, and the diaphragm blade of the MF lens 10 is narrowed down.

In the diaphragm driving mechanism, the diaphragm blades are narrowed down and opened by changing the forward and reverse rotation directions of the motor 1. Therefore,
By driving the motor 1 in the direction opposite to the above-described diaphragm blade narrowing operation, the body side narrowing lever that was pressing the diaphragm lever 10a of the MF lens 10 is returned, and the diaphragm of the MF lens 10 is restored. The lever 10a is returned by the urging force of the spring, and the aperture blades are also returned to the aperture open position.

As described above, according to this embodiment, by changing the mount surface of the interchangeable lens, each interchangeable taking lens having the driven portion itself serves as the drive switching means, so that the camera The photographer does not need to perform a switching operation, and since the mechanism has a simple structure with a small number of parts, the assembly process can be reduced and the cost can be reduced. Further, the structure is simple, so that the reliability of the mechanism is improved.

In the above embodiment, a disk-shaped member having a slit is used as the rotating member.
As the rotating member, for example, a member having a continuous cross-sectional shape of peaks and valleys, and a member having a shape in which a portion of the elastic plate that contacts the disk is engaged with the peaks and valleys is used. However, the same effect can be obtained. The same effect can be obtained even if the disc itself is made of a material having a high friction coefficient and a material having a high friction coefficient is applied to a portion where the elastic plate contacts the disc.

[0035]

As described above, according to the present invention, drive selection is made by the driven part itself, and the planetary gear mechanism is skillfully utilized to make a simple mechanical member of a disc and an elastic plate. By configuring the clutch mechanism with
The drive can be switched to the driven parts of the two systems that require both the forward and reverse rotation forces of one motor without using electrical means, and the drive force transmission with a simpler structure is possible. A device can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view of a driving force transmission device showing an embodiment of the present invention.

FIG. 2 is an enlarged central vertical sectional view of an essential part of the driving force transmission device of FIG.

3A is a side view of an autofocus (AF) lens, and FIG. 3B is a rear view of a mount surface side.

FIG. 4A is a side view of a lens for manual focus (MF), and FIG. 4B is a rear view of a mount surface side.

5 is an enlarged perspective view of the elastic plate shown in FIG.

6 is an enlarged sectional view of an essential part of a coupler section when the AF lens of FIG. 3 is attached.

FIG. 7 is an enlarged cross-sectional view of a main part of the coupler section when the MF lens of FIG. 4 is attached.

[Explanation of symbols]

1 ... Motor 2 ... Planetary gear box 3a ... Slit disk (first rotating member) 3b ... Slit disk (second rotating member) 4 ... Coupler 6a, 6b. Timing belt 7 ... Pulley 8 ... Camera body side mount 9 ... Auto focus (AF) lens (second driven mechanism) 10 ... Manual focus (MF) lens (first lens) Drive mechanism) 21 ... Pinion gear (sun gear) 22 ... Planetary gear 23 ... Carrier 23b ... Carrier output shaft 24 ... Internal gear (internal gear) 24a ... Internal output Shaft 25 ... Exterior case 26 ... Bearing 51 ... Elastic plate 51 (rotation locking member) 51a, 51b .. Bent piece

Claims (1)

[Claims] 1. A sun gear that is normally and reversely rotated by the output of a motor, a planetary gear that is constantly meshed with the sun gear, and a planetary gear that is rotatably supported and rotates coaxially with the sun gear. A carrier that is freely supported, and an internal gear that has internal teeth with which the planetary gear always meshes on the outer circumference of the revolution path of the planetary gear and that is rotatably supported coaxially with the sun gear. A first driven mechanism connected to the carrier, a second driven mechanism connected to the internal gear, a first rotating member that rotates integrally with the carrier around an axis, A second rotating member that rotates integrally with the internal gear around the axis and is separated from the first rotating member in the axial direction of the sun gear, the first rotating member, and the second rotating member. Located between the rotating member and the axial direction, the axial direction of the sun gear Is moved along one side to engage with the first rotating member to lock the rotation of the first rotating member, and moved to the other side to engage with the second rotating member. And a rotation locking member that locks the rotation of the second rotating member.