JPH0756719B2 - Link drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a link drive device, and more particularly to a link drive device for driving a cassette loading / ejecting mechanism such as a cassette tape recorder and an operation mode switching mechanism.

[Prior Art] A conventional link drive device will be described by taking a cassette mounting / discharging mechanism and an operation mode switching mechanism of a cassette tape recorder as an example.

FIG. 14 is a diagram showing an example of a conventional cassette loading / unloading mechanism in a cassette tape recorder.

In the figure, reference numeral 1 is a cassette mounting / discharging cam, and a cam groove 2 is formed on its main surface. Further, a column portion 3 is provided on the central axis of the cam 1, and the column portion 3 is provided with a cam groove which does not appear in the figure. A peripheral surface of the cassette mounting / discharging cam 1 is coupled to a drive source 4 such as a motor, and the cassette mounting / discharging cam 1 is rotated by the driving source 4.

One end of a substantially L-shaped first swing link 5 is engaged with the cam groove 2, and the other end of this swing link 5 is engaged with the slider pack 6 by sliding around. Then, install the cassette
When the discharge cam 1 is rotated, the first swing link 5 swings, and the slider pack 6 slides vertically in the drawing. Slider pack 6
By such a sliding operation, the position of the inserted cassette tape in the horizontal direction (corresponding to the vertical direction in FIG. 14) is restricted.

The operating end of the second swing link 8 is engaged with the cam groove formed in the column portion 3 of the cam. The second swing link 8 has a relatively large surface area, and one side (the lower side in FIG. 14) of the second swing link 8 is engaged with the holder cassette 9 in a rotating pair. Further, the second swing link 8 is rotatably held by the base arm 10 of which the upper left and right sides in the figure are partially drawn. The second swing link 8 responds to the rotation of the cassette mounting / ejection cam 1 by the base arm.
The holder cassette 9 swinging around the support portion of 10 and engaged in a rotating pair is moved in the vertical direction (the direction perpendicular to the paper surface in the figure). By this operation, the holder cassette 9 regulates the vertical position of the cassette tape 7.

FIG. 15 is a diagram showing an example of a conventional operation mode switching mechanism provided in a cassette tape recorder.

Referring to FIG. 15, the operation mode switching mechanism includes a drive source 11
And an operation mode switching cam 12, a swing link 13, and a mode plate 14. Operation mode switching cam
A circular cam groove 15 that is eccentric to the center axis of the cam 12 is formed on the main surface of the cam 12. Then, one end of the swing link 13 is engaged with the cam groove, and the other end is engaged with the mode plate 14 in a sliding pair. Therefore, when the operation mode switching cam 12 is rotated by the drive source 11, the swing link 13 swings around the fulcrum 16 and the mode plate 14
Slide up and down in FIG. The mode plate 14 is moved by the swing link 13, and the stop position thereof regulates the positions of the pinch roller, the idler for the reel rest, etc., and switches to the required operation mode.

The conventional cassette loading / ejecting mechanism and operation mode switching mechanism are configured as described above. Each of them is equipped with the dedicated motors 4 and 11 as a drive source, and is driven by the main motor for running the cassette tape. There were many types such as the ones for extracting the sources 4 and 11, but in any of them, the cassette loading / ejecting mechanism and the operation mode switching mechanism were separately and independently configured. Therefore, an individual drive source or cam, that is, a link drive device is required for each mechanism.

The table on the next page is a table showing the drive sources of the cassette loading / unloading mechanism and the operation mode switching mechanism in the conventional cassette tape recorder, and the control method in that case. The technical trends regarding the discharge and operation mode switching mechanism are shown.

[Problems to be Solved by the Invention] In the conventional cassette mounting / ejection and operation mode switching mechanism, as shown in the above table, both have a configuration in which the main motor is used as a drive source, and a dedicated motor is driven respectively. In the case of the configuration using the main motor as the drive source, a plunger corresponding to the cassette mounting / discharging mechanism and a link drive device for obtaining the necessary operating force are required. It can be seen that a plunger corresponding to the operation mode switching mechanism and a link drive device for obtaining the required operation force are required. Therefore, in most cases, for example, in a cassette tape recorder, the link drive device for the above mechanism, which is unrelated to the running of the cassette tape, must be constantly rotated during the running of the cassette tape (playing state). There was a problem that the tape running became unstable. Further, in many cases, the plunger is driven according to two states of ON / OFF of the solenoid to take out a necessary mode, so that a mechanism such as a cassette tape recorder equipped with an auto-reverse mechanism is complicated. However, there is a drawback that many solenoids of 3 to 4 are required, which is expensive and large in size.

Further, when a dedicated motor is used as a drive source, a dedicated motor and a link drive device are required respectively. Therefore, there is a drawback that the entire apparatus naturally becomes large and expensive.

Furthermore, it is possible to design one of them to be driven by the main motor and the other to be driven by a dedicated motor.
Even in that case, a link drive device for obtaining each required force is required, and the problems of increasing the space and increasing the number of parts have not been solved at all.

Therefore, a main object of the present invention is to provide a small-sized link drive device which can be commonly used for a plurality of mechanisms and has a small number of parts.

[Means for Solving the Problems] A link drive device according to the present invention includes a motor, a carrier having a sun gear connected to a rotation shaft of the motor, and a first cam groove. A first cam body having an internal gear with the same shaft as the first shaft, a first link provided in engagement with the first cam groove, and a second cam groove,
A second cam body comprising a planetary carrier rotatably attached to the shaft and a cam body having a third cam groove provided on a surface of the planetary carrier facing the second cam groove; A second link provided in engagement with the second cam groove, a third link provided in engagement with the third cam groove, and a cam formed in the second cam body. Any one of a fourth link provided in engagement, a planetary gear provided on the second cam body and meshing with the sun gear and the internal gear, and the second cam body and the internal gear. And a locking means for selectively engaging one of them to prevent rotation.

[Operation] The link drive device according to the present invention has the cam groove 2
The function of the two cam bodies is selectively blocked by the locking means, and the cam grooves are provided on the facing surfaces of the members constituting the one cam body, respectively, so that space utilization efficiency in the link drive device having a plurality of links is improved. Increase.

[Embodiment of the Invention] An embodiment of the present invention will be described below by taking a cassette tape recorder having an auto-reverse function as an example.
However, it is pointed out in advance that the present invention can be applied not only to the cassette tape recorder but also to the VTR, DAT, and other drive mechanisms.

FIG. 1 is a side sectional view showing the structure of a link drive device of a cassette tape recorder having an auto-reverse function. In this embodiment, the link drive device is configured to include a planetary gear device 35 that is a reduction mechanism.

Referring to FIG. 1, the power motor 31 is fixed to the main base 32 of the cassette tape recorder. The power motor 31 is a thin flat motor, and a pinion gear 34 is fixed to a rotary shaft 33 protruding above the main base 32.
The pinion gear 34 meshes with the planetary gear device 35 and drives the planetary gear device 35.

The planetary gear device 35 includes an internal gear 36, a fixed internal gear 37, an A planetary gear 38, an A carrier 41, a B planetary gear 42, a B carrier 43, and a C planetary gear 44. The internal gear 36, the A carrier 41, and the B carrier 43 are sequentially inserted in a stack in a cam post 45 fixed to the main base 32, and are rotatable around the cam post 45, respectively. The fixed internal gear 37 is fixed to the main base 32. The internal gear 36 is a pinion gear 34 and an A planetary gear.
It engages with 38 and rotates about the cam post 45 by the drive of the pinion gear 34. The rotational force of the internal gear 36 is transmitted to the A planetary gear 38. The A planetary gear 38 is rotatably supported by the A carrier 41, and has an internal gear 36 and a fixed internal gear.
Rotates while meshing with 37. Therefore, the rotational force of the internal gear 36 is reduced through the A planetary gear 38 and transmitted to the A carrier 41. The gear formed on the A carrier 41 meshes with the B planetary gear 42. The B planetary gear 42 is rotatably supported by the B carrier, and the A carrier 41 and the fixed internal gear.
Rotates while meshing with 37. Therefore, A carrier 41
Torque of the B carrier is reduced via the B planetary gear 42,
Transmitted to 43. Further, a C planetary gear 44 meshes with the sun gear formed on the B carrier 43. Then, the C planetary gear 44 reduces the speed of the mode switching cam 46 in which the internal gear is formed to a predetermined speed, and the C planetary gear 44
A cam body consisting of a cassette horizontal / head base retraction cam 47 which is a planet carrier and a cassette vertical cam 48 which is integrally formed on the planet carrier is decelerated to another predetermined speed different from the above predetermined speed. Is driven.

The operation mode switching cam 46 is rotatably engaged with the B carrier 43, and the B carrier 43, in other words, the cam post.
The center of rotation is 45. The lower surface of the operation mode switching cam 46 has a predetermined loop shape (endless shape) described later.
The cam groove 51 of is formed. A motion swing link 52 is fitted in the cam groove 51. Therefore, the operation swing link 52 is driven by the rotation of the operation mode switching cam 46. A roller 53 is inserted between the cam groove 51 and the motion swing link 52 to reduce the frictional force generated between them.
The movement is transmitted smoothly.

A locking recess 54 is formed on a part of the outer peripheral surface of the operation mode switching cam 46.
Are formed. A lock pin 55 is provided in the locking recess 54.
Are engageable.

The cassette horizontal / head base retreating cam 47 having the support shaft of the C planetary gear 44 is rotated about the cam post 45 by the rotation of the C planetary gear 44. A notch 61 forming a cam is formed in a part of the outer peripheral surface of the cassette horizontal / head base retreat cam 47 on the lower surface side, and a head base retreat link 62 is engaged with the notch 61. Therefore, when the cassette horizontal / head base retreat cam 47 rotates, the head base retreat link 62 is selectively brought into contact with the notch 61 or the outer peripheral surface of the cam 47, and the head base retreat link 62 swings.

A cam groove 63 is formed on the upper surface side of the cassette horizontal / head base retraction cam 47. The cam groove 63 is a predetermined loop-shaped endless groove as described later. One end of a cassette horizontal swing link 64 is engaged with the cam groove 63. Therefore, the cassette horizontal / head base retract cam
The rotation of 47 causes the cassette horizontal swing link 64 to perform a predetermined swing motion. A roller 65 is also inserted between the cam groove 63 and the cassette horizontal swing link 64 for preventing friction between them and for smooth engagement between the two.

A cassette vertical cam 48 is fixed to the cassette horizontal / head base backward cam 47. Therefore, as the cassette horizontal / head base retreat cam 47 rotates, the cassette vertical cam 48 also rotates about the cam post 45.
A cam groove 66 is formed on the lower surface of the cassette vertical cam 48 and is formed on the upper surface of the cassette horizontal / head base retreat cam 47.
Is formed to face. Then, one end of a cassette vertical swing link 68 is engaged with the cam groove 66 via a roller 67.

In addition, in this embodiment, the cassette horizontal / head base retreating cam 47 and the cassette vertical cam 48 are separately formed, and both are fixed, but the cassette horizontal / head base retreating cam and the cassette vertical cam 48 are integrated. It may be a molded article.

A notch 71 is formed in a part of the outer peripheral surface of the cassette horizontal / head base retraction cam 47. A lock pin 55 can be engaged with the notch 71.

The lock pin 55 is a protrusion formed on the lock plate 56. The lock plate 56 can move in the vertical direction as shown by an arrow 59 in the drawing, and when the lock plate 56 moves downward as shown in the drawing, the lock pin 55 causes the locking concave portion of the operation mode switching cam 46 to be locked.
It engages with 54 to prevent the operation mode switching cam 46 from rotating.
When the lock plate 56 moves upward, the lock pin 55 is notched in the cassette horizontal / head base retraction cam 47.
It engages with 71 and prevents rotation of the cassette horizontal / head base retreat cam 47 and the cassette vertical cam 48. Thus, the movement of the lock plate 56 causes the lock pin 55 to move the operation mode switching cam 46 or the cassette horizontal / head base retraction cam 47 (and the cassette vertical cam 4).
Any of the rotations in 8) is blocked, the operation mode is fixed to a predetermined motor when the cassette tape is moved, and the cassette is not loaded or unloaded while the cassette tape is being driven.

The mode switching brush 72 provided on the upper surface of the cassette vertical cam 48 is configured to come into contact with the mode switching circuit 74 provided on the lower surface of the upper base 73, and the mode switching brush 72 and the mode switching circuit 74 are provided. Depending on the contact position with the cassette vertical cam 48
The rotation angle of (and the cassette horizontal / head base retreat cam 47), that is, the current position for driving the cassette is detected.

Next, FIG. 2 to FIG. 3 will be described. 2 to 3 are views for explaining the link mechanism driven by the cassette horizontal / head base retreat cam 47 of FIG.

First, FIG. 2 is a plan view showing a horizontal blowing and discharging mechanism of a cassette tape. Then, FIG. 3 is an exploded perspective view for explaining the coupling relationship between the cassette horizontal / head base retreating cam 47 and the link mechanism shown in FIG. First, a horizontal blowing mechanism for a cassette tape will be described with reference to FIGS. 2 and 3.

As described with reference to FIG. 1, the upper surface of the cassette horizontal / head base retreat cam 47 has a cam groove for horizontally swinging the cassette.
63 is formed. The cassette horizontal swing link 64 has a substantially V-shaped or fan-shaped planar shape, and a head portion thereof is rotatably supported by a post 81 protruding from the main base 32. One end of the cassette horizontal swing link 64 engages with the cam groove 63 as described above, and the gear 82 is formed at the other end. A horizontal connecting link 84 is coupled via an arc amplification gear 83 that meshes with the gear 82. The circular arc amplification gear 83 and the horizontal connecting link 84 are
Together with 6,87 and the urging spring 88, the post 85 that vertically protrudes upward from the main base 32 is rotatably passed.
The holder spring 86 includes the circular arc amplification gear 83 and the horizontal connection link.
In FIG. 2, 84 is engaged with the circular arc amplification gear 83 and the horizontal connecting link 84 so as to rotate counterclockwise. Further, the holder spring 87 is engaged with the circular arc amplification gear 83 and the horizontal connecting link 84 so as to rotate the circular arc amplifying gear 83 and the horizontal connecting link 84 in the clockwise direction in FIG. And the holder spring 86 and the holder spring
87 is biased by a biasing spring 88, and biases the circular arc amplification gear 83 and the horizontal connecting link 84 in the above-described rotation directions. Therefore, the circular arc amplification gear 83 and the horizontal connecting link 84 are always kept in balance by the holder springs 86 and 87.

The arc amplification gear 83 is for amplifying the movement of the cassette horizontal swing link 64 and transmitting it to the horizontal connection link 84. The horizontal connecting link 84 is a bent longitudinal member, one end of which is rotatably supported by the post 85 and the longitudinal small hole 91 is formed at the other end thereof, as described above. The projection 93 of the slide piece 92 slides around the small hole 91 and is engaged in a pair. Slide piece 92
Is slidable along the long groove 95 of the arm EV94 and positions the cassette tape 96 in the insertion direction. Arm EV94, by base EV97 and Hol EV98,
It is supported with its rear end (the frontmost part in the cassette insertion direction) as the center of rotation. The tip end piece of the arm EV (the end piece at the end in the cassette insertion direction) is engaged so as to lift the holder cassette 101. Further, as shown in FIG. 4, the engagement protrusion (not shown) at the upper left end in FIG. 2 is engaged with the vertical link 103.

Next, FIGS. 4 to 6 are views for explaining the vertical descending and raising mechanism of the cassette tape. In particular, FIG. 4 is a plan view, FIG. 5 is a side view, and FIG. 6 is an enlarged perspective view of the connecting portion of the swing link.

Referring to FIGS. 4 to 6, on the lower surface of the cassette vertical cam 48, the cam groove 66 is formed as described above, and one end of the cassette vertical swing link 68 is formed in the cam groove 66. Engaged. The cassette vertical swing link 68, together with the vertical connecting link 103 and the biasing spring vertical 104, is rotatably supported by the post 102 protruding vertically upward from the bottom base. The cassette vertical swing link 68 and the vertical connection link 103 are connected by a bias spring vertical 104, and the cassette vertical swing link 68 and the vertical connection link 10 are connected.
The positional relationship with 3 is elastically coupled to the predetermined positional relationship. The tip of the vertical connecting link 103 is engaged with the engaging protrusion 105 of the arm EV94.

Next, the operation of the cassette tape loading / unloading mechanism will be described with reference to FIGS.

Before the cassette tape 96 is inserted, the cassette tape loading / unloading mechanism is in the state shown in FIG. In this state, when the cassette tape 96 is inserted in the direction of the arrow 106, the reel hole 107 on the insertion direction side of the cassette tape 96 is inserted.
The tip engaging portion 108 of the slide piece 92 is engaged with the. Next, by using the planetary gear device 35 described in FIG.
The head base backward cam 47 is rotated. Then, the cassette horizontal swing link 64 moves by being guided by a predetermined loop-shaped cam groove 63 formed eccentrically with respect to the rotation center axis of the cassette horizontal / het base retraction cam 47, The movement is amplified by the circular arc amplification gear 83 and transmitted to the horizontal connecting link 84. And the horizontal connecting link 84 is the second
The slide piece 92 is slid by rotating in the direction of arrow 111 in the figure. As a result, the cassette tape 96 is taken into the hold cassette 101. After the cassette tape 96 is taken into the holder cassette 101, the cassette vertical swing link 68 is rotated according to the rotation of the cassette vertical cam 48 shown in FIG. 4, and the rotation is transmitted to the vertical connection link 103. Therefore, the vertical connection link 103 causes the arm EV94 to move to the fifth position.
As shown by the alternate long and short dash line in the drawing, the base EV (and the holder EV98 (not shown)) is rotated. Therefore, the holder cassette 101 is lowered from the state where the arm EV94 and the upper surface thereof are aligned horizontally, and is brought into the state shown by the alternate long and short dash line in FIG. This state is the state in which the cassette tape 96 is mounted in the so-called PLAY state.

When ejecting the cassette tape 96, the cassette vertical cam 48
Also, by rotating the cassette horizontal / head base retreating cam 47, the cassette tape loading / unloading mechanism operates in the reverse order, and the cassette tape 96 is ejected. In this case, the cassette horizontal / head base retreat cam 47 and the cassette vertical cam 48 are rotated 180 ° in a predetermined direction to rotate the cassette tape 9
Put 6 in the loaded state and rotate it 180 ° in the same direction to eject cassette tape 96. That is, the cassette horizontal
The blow-out operation of the cassette tape is completed once by the operation of rotating the head base retreat cam 47 and the cassette vertical cam 48 once.

7 and 8 are views for explaining the head base retreating mechanism, in particular, FIG. 7 is a plan view and FIG. 8 is a partial side view of the mechanism portion.

With reference to FIGS. 7 and 8, reference numeral 47 is a cassette horizontal / head base retraction cam. The plane shape of the cassette horizontal / head base retraction cam 47 shown in FIG.
The plane horizontal shape of the cassette horizontal / head base retreating cam 47 shown in FIG. 2 is different from the plan view of the cassette horizontal / head base retreating cam 47 shown in FIG. This is because, in FIG. 7, only the outer peripheral shape of the lower half of the cassette horizontal / head base retraction cam 47 is taken out and drawn in order to explain the operation of the head base retraction mechanism. In other words, the shape of the cassette horizontal / head base retreat cam 47 in FIG.
7 shows an outer peripheral shape of a portion of the head base retreat cam 47 in contact with the head base retreat link 62.

The head base retreat link 62 is a long member, and one end thereof is rotatably supported by the post 81. The other end is in contact with the A link 112. The center portion of the head base retreat link 62 is in contact with the peripheral surface of the cassette horizontal / head base retreat cam 47, and the head base retreat link 62 is centered on the post 81 as the cassette horizontal / head base retreat cam 47 rotates. It is rocked. The A-link 112 is a longitudinal member arranged in the lateral direction. And
The head base retreat link 62 side is slidably supported by a pin 113 protruding from the side wall of the main base 32. The other end is engaged with the upper end of the B link 114 in a point pair. The B link 114 is attached to the side wall of the main base 32 by a pin 115 and rotates about the pin 115. The lower end of the B-link 114 rotates around and engages with one end of the C-link 116 in a pair. The C-link 116 is a longitudinal member arranged in parallel with the main base 32, and is rotatably provided around a pin 118 that is planted in the main base 32. A protrusion 119 is provided at the other end of the C-link 116, and the protrusion 119 is engaged with the head base 121. Head base
Reference numeral 121 is a substantially T-shaped base, which is slidably held with respect to the main base 32 by three guides 122, 123, and 124. A magnetic head 125 is placed at the center of the head base 121. Further, a spring 126 is hung on the head base 121, and the bed 126 is
It is biased to the left in FIG.

Next, the operation of the head base retracting mechanism will be described. The head base retract mechanism is used for loading cassette tapes.
When ejecting, the head 125 is retracted, that is, moved to the right in FIG.
It is a mechanism that moves it so that it does not interfere with the discharge. The head 125 is positioned in the state shown in FIG. 7 so that the head 125 contacts the tape surface of the cassette tape during PLAY of the cassette tape.

Now considering the PLAY state, in that state the cassette horizontal
The head base retreat cam 47 is in the state shown in FIG.
That is, the notch of the cassette horizontal / head base retreat cam 47 is in contact with the head base retreat link 62. Therefore, the A link 112 is relatively moved in the A direction of the arrow 127. Therefore, in that state, B link
The lower end of 114 is near the B of arrow 128, so C-link 11
One end of 6 is swung to the B side of arrow 129. Therefore,
The head base 121 that engages with the other end of the C-link 116 has a seventh
It is located on the left side in the figure, and the head 125 is in contact with a tape surface (not shown).

On the other hand, when the cassette tape is mounted and ejected, the cassette horizontal / head base retreat cam 47 rotates and the head base retreat link 62 comes into contact with the circumferential surface of the cassette horizontal / head base retreat cam 47. Therefore, the head base reverse link 62 is connected to the cassette horizontal / head base reverse cam 47.
The circumferential surface of FIG. 7 causes the post 81 to be rotated more to the right than the state shown in FIG. Then, in this state, the other end of the head base retreat link 62 causes the A link 112 to slide in the B direction of arrow 127. Therefore, the lower end of the B link 114 moves in the A direction of the arrow 128, and the one end of the C link 116 swings in the A direction of the arrow 129. Therefore, the head base 121 engaging with the other end of the C link 116 is moved rightward in FIG. 7 against the force of the spring 126. Therefore, the head 125 is retracted to the right from the state of contact with the tape surface.

FIG. 9 summarizes the positional relationship between the rotation angles of the cassette horizontal / head base retreating cam 47 and the cassette vertical cam 48, and the link mechanism driven by them, as described above. In FIG. 9, the cassette horizontal / head base retreat cam 47 which is actually integrated is shown separately as a cassette horizontal cam and a head base retreat cam for convenience of description. Then, as described above, the cassette horizontal cam, the cassette vertical cam, and the head base retreat cam rotate integrally about the same shaft center 45. By performing one rotation (360 °), one cycle of loading / unloading the cassette tape is completed. Therefore, the cassette horizontal cam and the cassette vertical cam are provided with predetermined loop-shaped cam grooves 63 and 66 whose radii change around the rotation axis of the cam and which are eccentric to the rotation axis of the cam.

FIG. 10 is a view showing the shape of the cam groove 63 formed in the cassette horizontal / head base retreating cam 47 and the positional relationship between the cam groove 63 and the notch 61. The horizontal cam groove 63 has a shape symmetrical with respect to a line connecting the positions of EJECT and PLAY. In the EJECT state, the center radius of the cam groove 63 is set to r _EH that is the largest. The radius of the cam groove 63 gradually decreases during 75 ° from the EJECT state until the cassette horizontal / head base retreat cam 47 rotates clockwise and reaches the point A. At the point A, the radius of the cam groove 63 becomes r _PH . Become. The cam groove 63 has a constant radius r _PH during 120 ° from that state to the point B including the PLAY point. The radius of the cam groove 63 is gradually increased in the range of 75 ° from point B to EJECT. In this way, the horizontal cam groove 63 of the cassette horizontal / head base retreat cam 47 is the farthest from the cam center in the EJECT state, and conversely, the cam groove is the most in the cam center in the PLAY state and before and after that. It is a loop-shaped groove that is eccentric to the center of the cam so that it is brought closer to it. Therefore, the shape of the eccentric loop-shaped groove changes according to the rotation of the cassette horizontal / head base retreat cam 47, and the engaging portion of the link is guided. Notch
71 is for the lock pin 55 to engage.

FIG. 11 shows a vertical cam groove formed on the cassette vertical cam 48.
It is a figure which shows the shape of 66. Vertical cam groove 66 is also EJECT and PLA
It has a line-symmetrical shape with respect to the line connecting with Y. The center of the cam groove 66 has a radius r _EV with respect to the center of the cam during 150 ° around EJECT. Then, the cassette vertical cam 48 rotates clockwise from EJECT, and the radius of the cam groove 66 gradually increases from r _EV to r _PV during 60 ° from point C to point D. The radius of the cam groove 66 is r _PV between 90 ° around PLAY from point D to point F, and the radius of the cam groove is 60 ° between point F and point G. Gradually decreases from r _PV to r _EV . Therefore, the cassette vertical cam
The radius of the cam groove 66 with respect to the center of the cassette vertical cam 48 changes according to the rotation of the cassette 48, the engaging portion of the link is guided, and the link performs a predetermined operation.

FIG. 12 is a plan view for explaining the pinch roller switching mechanism. Since the cassette tape recorder of this embodiment has the auto-reverse function, the two pinch rollers can be switched alternately depending on the rotation direction of the cassette tape. With reference to FIG. 12, a cam groove 51 is formed in the operation mode switching power 46. One end of the longitudinal motion swing link 52 is rotatably supported by the post 81.
Then, the protrusion 13 is provided at the center of the motion swing link 52 in the longitudinal direction.
1 is provided, and this projection 131 is a sliding pair with the cam groove 51. The other end of the motion swing link 52 is engaged with the D link 132. The D link 132 slides in the direction of arrow 133 in accordance with the operation of the operation swing link 52. The other end of the D link 132 is engaged with the E link 134. The E-link rotates about a pin 135 provided on the main base 32 and transmits the movement of the D-link 132 to the cam CH136. The cam CH136 is a plate-like long member arranged parallel to the main base 32, and is held by guides 137 and 138 fixed to the main base 32, and its sliding direction is guided. Then, the cam CH136 slides in the direction of arrow 139. Pinch roller
141 and 142 are provided in association with both ends of the cam CH 136, respectively. That is, the pinch rollers 141 and 142 are rotatably attached to the main base 32 around the posts 143 and 144, and the stoppers 145 and 146 are engaged with the notches 147 and 148 of the cam CH 136 in a predetermined state. The shape of the notches 147 and 148 causes the 12th
In the state shown in the figure, the cam CH136 is moving in the A direction of the arrow 139, the pinch roller 141 is in the operating state, and when the reverse cam CH136 is moving in the B direction of the arrow 139, the pinch roller 142 is in the operating state. It is configured. Such sliding movement of the cam CH136 is caused by the rotation of the operation mode switching cam 46. The operation swing link 52, the D link 132, the E link 1
Transmitted through 34.

FIG. 13 shows a cam groove 51 formed in the operation mode switching cam 46.
It is a figure for explaining the shape of. The cam groove 51 has a left-right and up-down symmetrical shape. Then, at the point L in FIG. 13, the operation mode switching cam 46 is farthest from the center, and at the point R, the operation mode switching cam 46 is closest to the center. And
When the protrusion 131 of the motion swing link 52 is located at the L point, the left pinch roller 141 is in the operating state, and when the protrusion 131 is at the R point, the right pinch roller 142 is in the operating state. ing. Thus, in this embodiment, if the operation mode switching cam 46 makes one rotation, the pinch rollers 141, 14
2 can be switched twice. The four locking recesses 54 formed symmetrically on the operation mode switching cam 46
Engage with the lock pin 55.

As shown in FIG. 1, the operation mode switching cam 46 is
The cassette horizontal / head base backward cam 47 and the cassette vertical cam 48 are driven at a different reduction ratio.
Therefore, since it is driven by an output gear that is different from the cassette horizontal / head base reverse cam 47 and the cassette vertical cam 48, it can be operated when the cassette horizontal / head base reverse cam 47 is stopped, and vice versa. ,
When the operation mode switching cam 46 is operated, the operation of the cassette horizontal / head base retraction cam 47 can be stopped. Lock pin 55 protruding from the lock plate 56
Is for that. Therefore, the lock plate 56 (see FIG. 1) slides up and down according to the operation state of the cassette tape recorder to selectively lock the cassette horizontal / head base retreat cam 47 or the operation mode switching cam 46 inoperable. .

[Effect of the Invention] According to the present invention, the function of the two cam bodies having the cam grooves is selectively blocked by the locking means, and the cam grooves are respectively provided on the facing surfaces of the members constituting the one cam body. Therefore, the space utilization efficiency in the link drive device having a plurality of links is improved, and a small-sized link drive device can be obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view showing the structure of a link drive device according to an embodiment of the present invention. FIG. 2 is a plan view showing a horizontal suction / discharge mechanism for a cassette tape. FIG. 3 is an exploded perspective view for explaining the coupling relationship between the cam and the link mechanism. FIG. 4 is a plan view for explaining the vertical descending and raising mechanism of the cassette tape. FIG. 5 is a side view for explaining the vertical descending / raising mechanism of the cassette tape. FIG. 6 is an enlarged perspective view of the connecting portion of the swing link.
FIG. 7 is a plan view of the head base retracting mechanism. 8th
The figure is a partial side view of the head base retraction mechanism. FIG. 9 is a diagram showing the positional relationship between the rotation angles of the cassette horizontal / head base retreat cam 47 and the cassette vertical cam 48 and the link mechanism. FIG. 10 is a view showing the shape of the cam groove 63 of the cassette horizontal / head base retreating cam 47. First
FIG. 11 is a view showing the shape of the cam groove 66 of the cassette vertical cam 48. FIG. 12 is a plan view showing a pinch roller switching mechanism. FIG. 13 is a view showing the shape of the cam groove 51 of the operation mode switching cam 46. FIG. 14 is a diagram showing an example of a cassette loading / unloading mechanism in a conventional cassette tape recorder. FIG. 15 is a diagram for explaining an operation mode switching mechanism in a conventional cassette tape recorder. In the figure, 31 is a power motor, 35 is a planetary gear device, and 36
Is an internal gear, 37 is a fixed internal gear, 38 is an A planetary gear, 41 is an A carrier, 42 is a B planetary gear, 43 is a B carrier, 44 is a C planetary gear, 45 is a cam post, 46 is an operation mode switching cam, 47 Is a cassette horizontal / head base retraction cam, 48 is a cassette vertical cam, 51 is a cam groove, 52 is a motion swing link, 54 is a locking recess, 55 is a lock pin, 56 is a lock plate, 61 is a notch, and 62 is a notch. A head base retreat link, 63 is a cam groove, 64 is a cassette horizontal swing link, 66 is a cam groove, 68 is a cassette vertical swing link, and 71 is a notch.

Claims (1)

[Claims] 1. An internal gear having a motor 31, a carrier 43 having a sun gear connected to a rotation shaft of the motor 31, a first cam groove 51, and a shaft 45 of the sun gear being the same shaft. A first cam body 46 having a first cam body, and a first link provided in engagement with the first cam groove 51.
52, a second cam groove 63, and a planet carrier 47 rotatably attached to the shaft 45 and the second carrier of the planet carrier 47.
Second cam body comprising a cam body 48 having a third cam groove 66 provided on the surface facing the second cam groove 63, and a second cam body provided in engagement with the second cam groove 63. Link
64, and a third link provided by engaging with the third cam groove 66.
68, a fourth link 62 provided by engaging with a cam 61 formed on the second cam body, and provided on the second cam body and meshing with the sun gear and the internal gear. A link drive device comprising: a planetary gear (44); and a locking means (55) for selectively engaging one of the second cam body and the internal gear to prevent rotation.