JPH077537B2 - Cam operation mechanism - Google Patents

Description

The present invention relates to an operating mechanism using a cam, and more particularly to a cam forming method suitable for downsizing the operating mechanism.

[Conventional technology]

The cam operating mechanism is a mechanism for converting the direction of movement and the amount of movement, and is used in a wide variety of devices. For example, in a video tape recorder, in so-called mode operation, 1)
Fast forward / rewind, 2) stop, 3) recording / playback,
4) In order to support multiple modes such as reverse playback, b) various types of operation targets such as a) brakes, b) attachment / detachment of pinch rollers, c) operation of tension control arm, etc. A cam operating mechanism is used.

As an example thereof, a slider-shaped cam member provided with a guide portion extending in the moving direction is known, and is described in, for example, Japanese Patent Application Laid-Open No. 58-60450.

[Problems to be solved by the invention]

In the cam operating mechanism, when the operation patterns of a plurality of mechanical elements are different, it is necessary to add and form individual cams for each. As a countermeasure against this conventional technique, 1) a cam member is used. Extend in the longitudinal direction and connect the cams in series.

2) The cam member is expanded in the width direction and the cams are installed on both sides of the cam member, or a plurality of cam patterns are installed in parallel in the width direction.

3) The thickness of the cam member is increased in the thickness direction and the cam member is multilayered in the thickness direction to provide a plurality of cam patterns.

However, in any case, there is a problem that the cam member becomes large in size and the operating mechanism, and eventually the entire mounting device, becomes large in size.

It is an object of the present invention to provide a cam operating mechanism that is small and is compatible with a plurality of mechanical elements having different operation patterns.

[Means for solving problems]

The above-mentioned object is achieved by installing the cam portion in the guide portion of the cam member and causing the cam contact member of the mechanical element to operate in the guide portion.

[Work]

By installing the cam portion in the guide portion of the cam member, the wall thickness of the cam member around the guide portion, which has been a dead space up to now, can be effectively utilized for the cam step amount, and the cam member can be made large. It is possible to add more cam patterns without changing.

Further, by operating the contact portion of the mechanism element with the cam in the guide groove, the mechanism element can also contact the cam in the guide groove, and a predetermined operation can be taken out. can do.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. This embodiment is applied to a mode operation mechanism of a video tape recorder. First, the entire apparatus will be described, and then the cam operating mechanism will be described in detail.

FIG. 2 is a plan view of a video tape recorder to which the present invention is applied, where 1 is a chassis, 2 is a tape guide drum on which a magnetic head is mounted, 3 is a tape 6 wound around a supply reel 4 and a take-up reel 5. Cassette 7 which has a built-in cassette, 7 is a capstan to which a motor 9 is directly connected to the lower end, 8 is a pinch roller, 10
Is an erasing head for erasing over the entire width of the tape 6, and 11 is an audio control head for recording and reproducing audio signals and control signals at the upper and lower ends of the tape 6. When the cassette 3 is installed in the device, the cassette 3
The front lid 12 opens. Further, a tension pin 16, a guide roller 17 and a tilt pin 18 are inserted into the opening 13, and a guide roller 19 and a tilt pin 20 are inserted into the opening 14.
The inclined pin 21 and the capstan 7 are inserted into the opening 15 at the positions shown by the broken line and the solid line, respectively. At this time, the pinch roller 8 is also in the position shown by the broken line. When the loading operation is performed, each guide moves while pulling out the tape 6.
The guide roller 17 and the inclined pin 18 move horizontally as a pair and are positioned near the tape guide drum 2. The guide roller 19 and the inclined pin 20 form a pair and move horizontally up to the vicinity of the audio control head 11 and thereafter move diagonally downward to be positioned near the tape guide drum 2, and the tape is guided to the tape guide drum 2. 6 to almost 270
゜ Wind up. The tilt pin 21 moves horizontally from behind the tilt pin 20 and is fixed on the upstream side of the audio control head 11, corrects the attitude of the tape 6 and guides it to the take-up reel 5.
As a result, the tape 6 comes out of the cassette 3, passes through the tension pin 16, the height regulation guide 22, the erasing head 10, the guide roller 17, and the inclined pin 18, and is wound around the tape guide drum 2 in a spiral shape at a predetermined angle. The guide roller 19, the inclined pin 20, the inclined pin 21, the fixed guide 23, the audio control head 11, the height regulation guide 24, and the fixed guide 25 are pressed and driven by the capstan 7 and the pinch roller 8.
It reaches the take-up reel 5. FIG. 3 shows a side view after completion of loading, and FIG. 4 shows a side view after completion of unloading. In FIG. 3, 26 is a guide base and a guide roller.
17 and the inclined pin 18 are planted and positioned and held by the catcher 28, and the guide roller 19 and the inclined guide 20 are also planted 27 on the guide base.
Positioned by As shown in the figure, the tape guide on the exit side of the tape guide drum 2 is descended by a width substantially larger than that on the entrance side. As a result, the tape guide drum 2 can be arranged under the lid 12 that opens in front of the cassette 3 by reducing the inclination angle of the tape guide drum 2 and arranging the tape guide drum 2 at a position slightly lower than the cassette 3. We are trying to make it smaller and thinner.

Next, the loading mechanism will be described. FIG. 5 shows the guide moving member on the exit side. Guide roller 19 and inclined pin
The guide base 27 in which 20 is to be erected is rotatably supported in the plane by a connecting plate 29 as shown by an arrow in the figure, and the connecting plate 29 is also rotatably supported in the plane by a connecting plate 30. It
Further, the connecting plate 30 is an output side drive member that can swing in the vertical direction.
It is supported at one end of 31. The output side drive member 31 has an arc shape, and a gear portion 31a is provided on the outer periphery thereof.
FIG. 6 shows the guide moving member on the entrance side. Guide roller 17
The guide base 26 on which the tilting pins 18 are erected is rotatably supported in the plane by a connecting plate 32, and the connecting plate 32 is also rotatably supported in the plane by one end of the entrance side driving member 33. To be done. The entrance-side drive member also has an arc shape, and a gear portion 33a is provided on the outer periphery thereof. FIG. 1 (a) shows the cam 34 as viewed from above. Cam 34 up and down 2
Gears 34a and cams 34d from the left on the top.
There is a stopper surface 34b corresponding to a Geneva gear (described later), a cam portion 34c corresponding to the mode operation after loading, a cam portion 34f corresponding to the middle of loading / unloading, and a mode operation after the unloading. There is a cam portion 34e, which has an arc shape as a whole. These are the input drive member 33 and the output drive member 3 from the top.
1, the cam 34 is arranged concentrically on the chassis in this order.

FIG. 7 shows the above-mentioned three driving members 31 and 33 and the cam 34.
(A) is for ejecting, (E) is for loading completion, and (F) is for mode operation such as recording / reproducing. The shape of each member is simplified and shown in an arc shape. As will be described later, as shown in FIG. 7, with respect to the movement of the cam 34, the entrance side driving member 33 rotates in the opposite direction at substantially the same speed, and the exit side driving member 31 rotates in the same direction at almost the double speed.

FIG. 8 is a perspective view of the catcher 28. The tape guide drum 2 has an integral structure for positioning the tape guide group on the input side and the tape guide group on the output side. For the tape guide group on the entry side, the shaft portion at the lower part of the guide roller 17 is positioned by the V groove 28a and the upper part is regulated by the U groove 28b to prevent the guide roller 17 from falling in a direction perpendicular to the entering direction. . Guide roller 17
As for the height of the stopper surface 28c
It is regulated by abutting against. The inclination of the inclined pin 18 is determined by the side surface of the guide base 27 contacting the wall 28d. The same applies to the tape guide group on the output side. The position and angle of the guide roller 19 are determined by the V groove 28e and the U groove 28f, and the height is determined by the stopper surface 28g. The inclination of the inclination pin 20 is restricted by the wall 28h. Further, a notch 28i is provided between the V groove 28e and the U groove 28f of the catcher 28. FIG. 9 is a side view of a partial cross section of the catcher 28, (a) showing an unloading state and (b) showing a loading completed state. In the unloading state, one end of the cam 34 and one end of the exit side driving member penetrate the cutout portion 28i, but these members are cut out by the loading operation.
Since it escapes from i, the guide roller 19 and the inclined pin 20 can be held at predetermined positions in the loading completion state.

FIG. 10 is a perspective view showing a guide member 68 of the tape guide group, and FIG. 11 is a side view showing a support structure of the tape guide group by the guide member 68. The guide member 68 has an integral structure having a guide part for the entrance tape guide group and a guide part for the exit tape guide group, and the tip of the guide part of the exit tape guide group descends along the tape running path. Have a department. The tip 68a of the cross section of the guide member 68 is the guide base 26 or 2
It engages so as to be gripped in 7, and regulates the movement path of the guide base 26 or 27.

FIG. 12 shows a moving mechanism of the inclined pin 21 arranged on the exit side. FIG. 12 (a) shows a state corresponding to the unloading state shown in FIG. 16 (a). The gear 69, which is rotatably supported coaxially with the arm 48, has a bent portion of the gear 69 at both ends thereof.
69b and the left end 48a of the arm 48 are biased by the spring 70, and the right end 48b of the arm 48 and the bent portion 69c of the gear 69 are in contact with each other. From this state, the 12th corresponding to FIG. 16 (c)
When the mode shifts to the state shown in FIG. 7B and the arm 48 rotates so that the pinch roller 8 comes into pressure contact with the capstan 7,
The arm 72 having the gear portion 72a that meshes with the gear portion 69a of the gear 69 rotates, and the tilt pin 21 that is planted at the tip of the arm 72 is positioned at a predetermined position by the catcher 73. After the positioning, the arm 48 is further rotated so that the arm 48 is bent against the spring 70 as shown in FIG.
By separating from the 69c, the crimping force is secured to the catcher 73 of the inclined pin 21.

By driving the tilt pin 21 at the above timing, the tilt pin 21 is loaded from the rear of the guide base 27. That is, the inclined pin 21 and the guide base 27
Since the movement loci of the guides partially overlap, when the guide base 27 precedes the overlapping part, the cam
The position of the arm 42 and the speed reduction ratio of the drive system of the arm 72 are set so that the 34 and the arm 42 engage with each other to drive the inclined pin 21.
Therefore, since the movement of the arm 72 is controlled by the movement of the cam 34, there is no interference at the overlap portion.

As described above, the loading mechanism and the mode operation in this apparatus are performed centering on the entrance side drive member 33, the exit side drive member 31, and the cam 34. FIG. 13 is a perspective view showing the assembly structure of the above-mentioned three arc-shaped members. Cam 34
Is engaged with the guide pins 74a to 74e planted in the chassis 1 and the groove 34g formed around the entire lower portion of the cam 34,
It is guided rotatably on the chassis 1. Guide pins 74a-74e
In the rotation range of the cam 34 shown in FIG. 10, three or more are always arranged to engage with the groove 34g of the cam 34. The delivery side drive member 31 is cammed by the guide pins 76a and 76b.
The guide pin 75a, 75b and the output side drive member elongated holes 31b, 31c are rotatably held by the 34, and a pin (not shown) and a cam 34 which are set up in the lower part of the output side drive member 31. By engaging with the elongated hole portion 34b, the cam 34 can rotate concentrically with the cam 34. Since the entry side drive member 33 has a small turning angle as shown in FIG.
At the outer circumference, the gears 75 and 77 are always meshed with and held by the entry-side drive member gear portion 33a. The exit side drive member 31 and the cam 34 are
As shown in Fig. 13, it rotates in the same direction over an angle of approximately 180 degrees or more. Therefore, as shown in FIG. 13, the angle of the elongated holes 31b and 31c formed in the output side drive member 31 is changed by replacing the cam 34 with the substrate that holds the rotation of the output side drive member 31. The relative rotational angle difference between the side drive member 31 and the cam 34 can be increased. That is, 18
When the ring that rotates over 0 degrees or more is held on the substrate, the oblong hole angle of the ring can be reduced according to the present embodiment as compared with the case where the oblong hole portion of the ring requires 180 degrees or more. Problems such as play and strength can be minimized.

In the present embodiment, the case where the sliders (rings) having an arc shape in which the upper and lower three sheets are overlapped with each other has been described, but the same applies to an annular ring. Also, as shown in FIG. 14, depending on the loading device that guides the two tape guides in one direction, three sheets that rotate in the same direction or one of the rings may be used as the drive ring and the tape guide guide ring. It may have a two-sheet configuration.

Further, the ring guide may be held by a block 78 and a groove integrated with the ring as shown in FIG. 15 instead of the elongated hole and the pin.

Next, the cam operating mechanism of this embodiment will be described in detail.

First, regarding the main body of the cam 34, the form seen from the above is as described above, but FIG. 1 (b) shows a state in which the upper and lower sides are interchanged from FIG. 1 (a).

On the lower surface, a groove-shaped engaging groove 34g that engages with the guide pin 74 set up on the chassis 1 is formed.

Further, two in-groove cams 34h are formed in a concave shape from the outer peripheral wall of the engaging groove 34g to the outer periphery. The in-groove cam 34h is formed shallower than the engaging groove 34g. (Details will be given later with reference to FIG. 18) FIG. 16 shows a cross section taken along the line AA ′ of the cam 34 in FIG. 1 (b) and the drive system. (A) is unloading and (b) is loading / unloading. During loading, (c) shows a loading state. The cam 34 is driven by a gear 35 driven by a drive source (not shown) meshing with the gear portion 34a. When the cam 34 rotates, the gear 36 that meshes with the gear 34a rotates, and the delivery-side drive member 31 moves to the gears 37, 38.
A gear 39 that rotates integrally via a gear 38 and a spring (not shown) for pressing is driven by engaging with a gear portion 31a. Similarly, the entrance-side drive member 33 is driven by a gear 55, which has a pressure-bonding spring (not shown) incorporated therein, via the gears 40 and 41, meshing with the gear portion 33a. When the loading is completed (c), the rotation of the gear 36 is stopped by the Geneva gear described later, and the engagement between the gear 36 and the gear portion 34 is released. On the other hand, in the state of (b) during loading, the tip of the cam 34 and the arm 42 are engaged, the arm 42 rotates about the shaft 43, and the arm 44 rotates about the shaft 45. The arm 44 is connected to the arm 48 by the arm 46 via the shaft 47.
Since it is engaged with the shaft 49, the pinch roller 8 pivotally supported by the arm 48 is moved to the loading position. arm
Since 48 is biased in the direction of arrow A by a spring, the cam
In the state (a) in which the arm 34 and the arm 42 are not engaged, the pinch roller 8 is retracted to the unloading position. (B)
When the cam 34 rotates further from the state of (3) and becomes the state of (c),
The arm 42 engages with the cam portion 34d, and the toggle mechanism formed by the arms 44 and 46 causes the pinch roller 8 and the capstan 7 to move.
Press against. The shaft 45 is erected on the arm 51 supported by the shaft 52, and the arm 51 is always pulled by the spring 53 and its position is regulated by the stopper 54. Therefore, the arm 42 rotates even after the movement of the pinch roller 8 is stopped. Arm 51
Is separated from the stopper 54 against the spring 53,
The crimping force between the pinch roller and capstan is secured.

FIG. 17 shows a cross section of the cam 34 taken along the line BB ′ in FIG. 1 (b) and a mode operating mechanism. FIG. 17 (a) shows unloading,
(B) is in the middle of loading / unloading, (c)
Indicates the loading state. Reference numeral 36a is a Geneva gear portion provided integrally with the gear 36. First, the arms (mechanical elements) 55 and 60 that come into contact with the outer periphery of the cam 34 will be described. One end of the arm 55 is engaged with the cam portion 34c or 34e, and is biased counterclockwise around the shaft 56 by the spring 57 attached to one end. A brake member 58 is attached to the other end of the arm 55 to apply a braking force to the supply reel base 59. Arm 60
Is engaged with the cam portion 34c or 34e, and a spring 61 attached to one end
Is urged clockwise about the shaft 62. The arm 63 has an arm 63a engageable with the shaft 60a on the arm 60, and a spring 65 is attached to one end of the arm 63 and is biased in a counterclockwise direction around the shaft 62. Further, a brake member 64 is attached to the other end to apply a braking force to the drive disc 66 that engages with the take-up reel 5. (A) shows the stopped state after unloading,
The arm 55 engages with the concave portion of the cam portion 34e, and a braking force is applied to the supply reel base 59. At this time, since the concave portion and the arm 55 are not directly engaged with each other, the braking force is determined only by the force of the spring 57 and is stable regardless of the stroke of the cam portion 34c. Further, the arm 60 engages with the convex portion of the cam portion 34e, and the spring 61
Against the shaft 60a and the arm 63a, the spring 65a
The braking force is applied to the drive disc 66 by the biasing force of the
In the state of (b), the arms 55 and 60 are engaged with the cam portion 34f, and only the braking force applied to the supply reel base 59 is released. Therefore, at the time of loading, the tape 6 is basically delivered from the supply reel side. The state (c) shows a recording / reproducing state, in which a braking force is applied to the supply reel base 59, but the arm 60 engages with the concave portion of the cam portion 34c and is rotated by the pulling force of the spring 61, and the shaft is rotated. 60a engages with the arm 63a to move the arm 63 to the spring 65
The brake force to the drive disk 66 is released by rotating the drive disk 66 against the drive disk 66. At this time, the Geneva gear portion 36a and the stopper surface 34b are engaged with each other, whereby the rotation of the gear 36 is stopped and the drive member is stopped.
While 31 and 33 stop, the crimping force of each tape guide group to the positioning member is maintained. In this way, by transmitting the movement of the cam 34 to the drive member via the switching mechanism such as the Seneba gear, it is possible to easily cope with an increase in the number of operation modes.

Here, as described with reference to FIG. 17, the outer peripheral side surface of the cam 34 is completely exhausted during the entire operation period from unloading to loading, and mode operation.
Increasing the size of the cam 34 is inevitable as in the prior art.
Here, it was necessary to further increase two mechanical elements in this device, and the present invention was applied.

Next, the arms 90 and 91 that come into contact with the inside of the engagement groove 34g of the cam 34 according to the present invention will be described with reference to FIG.

Arms 90 and 91 have cam pins 90a set up at one end.
And 91a are the inner wall of the groove 34g of the cam 34 or the cam 34 in the groove.
It is biased counterclockwise and clockwise about shafts 94 and 95, respectively, which are engaged with h and are mounted in the middle part, around shafts 94 and 95 which are planted in the chassis 1, respectively. The rotation mechanism of the tension control arm is connected to the other end of the arm 90, and the tape winding torque varying mechanism is connected to the other end of the arm 91, but they are directly involved in the cam operation mechanism of the present invention. It is omitted because it is not done.

As shown in the cross-sectional view of FIG. 18, the cam pins 90a and 91a project from the lower surface side of the cam 34 into the engaging groove 34g and are engaged therewith, and are formed shallower than the engaging groove 34g as described above. It is set to be short so that it can be engaged with the cam 34h in the groove. On the other hand, the guide pin 74 of the cam 34 is engaged with the inner part of the engagement groove 34g, the guide pin 74 does not enter the groove inner cam 34h, and the cam 34 is always in the radius of the groove 34g. It is held so that it can rotate smoothly.

The arm 90 is being loaded (Fig. 17 (b)).
Moreover, the arm 91 is a mechanical element that requires a predetermined operation during unloading (FIG. 17 (a)).

As shown in FIG. 17, the cam pin 90a of the arm 90 is (b)
Only during loading of the figure, it falls into the cam 34h in the groove. The cam pin 91a of the arm 91 falls into the groove cam 34h only when unloading as shown in FIG. Both of them are connected to the following transmission mechanism to perform a predetermined operation when the cam pin falls into the groove cam 34h.

Here, in this embodiment, the positions of the cam pins 90a and 91a are selected so that the grooved cams 34h deviate from each other in the circumferential direction of the cams 34c and 34e in the circumferential direction of the cams. In order to reduce the size of the cam 34, the wall thickness from the engagement groove 34g to the outer peripheral side surface in the radial direction is set to the minimum thickness at which the cam step amount of the outer peripheral cams 34c and 34e can be measured. Also, the cam in the groove
It is possible to operate with the same cam step amount as 34h and the outer peripheral portions 34c, 34e. Therefore, if the concave portions of the outer and inner circumferential cams are displaced in the circumferential direction, the radial width of the cam 34 is not increased, and the cam 34 is not cut in the radial direction. It is possible to add cam patterns.

That is, in this embodiment, although two mechanical elements are added, the effect that the cam 34 is not upsized due to this is obtained.

Although the cam 34 has an arc shape in this embodiment, it may have a linear slider or an annular shape.

Also, due to the pursuit of a thinner cam 34, etc., if the engagement height between the cam pin 90a and the cam 34 in FIG. The depth is set to be the same as that of the engagement groove 34g to ensure the engagement height between the cam pin 90a and the cam 34, and even if the guide pin 74 comes to the position of the cam in the groove, there are always three or more guide pins. The number of guide pins 74 may be increased so as to be engaged with the rounded portion having no inner cam. Alternatively, the guide pin 74 may be a convex continuous rail that fits into the engagement groove 74 except for the engagement portions of the cam pins 90a and 91a.

Further, since the cam 34 of the present embodiment has a large rotation angle, a long groove-shaped engaging portion is provided, but when the rotation angle is relatively small, the long groove is formed as shown in FIG. Slot
It may be 96.

Further, as shown in FIG. 20, the elongated hole cam 96a may be formed continuously with the elongated hole 96. In this case, the engaging arm 97 can eliminate the biasing spring such as the arm by minimizing the play between the long hole cam 96a and the cam pin 97a.

〔The invention's effect〕

According to the present invention, it is possible to add a new cam pattern without increasing the size of the cam member or without increasing the size of the cam member at all. Therefore, it is possible to reduce the size of the cam operating mechanism and hence the mounting device thereof. is there.

[Brief description of drawings]

FIG. 1 is a perspective view of a cam used in one embodiment of the present invention,
FIG. 2 is a plan view showing an embodiment of the present invention, FIGS. 3 and 4 are side views of a catcher portion, FIGS. 5 and 6 are perspective views of a loading ring, and FIG. 7 is a ring operation. 8 is a perspective view of the catcher, FIG. 9 is a side sectional view of the catcher, FIG. 10 is a perspective view of the tape guide guide, FIG. 11 is a side view of the tape guide, and FIG. 12 is a tape. FIG. 13 is a plan view of the drawer guide, FIG. 13 is an exploded perspective view of the ring, FIG. 14 is a perspective view showing another example of the ring structure, FIG. 15 is a side sectional view of FIG. 14, FIG. 16 and FIG. Is a plan view showing an operation of a cross section of an upper stage and a lower stage of a cam, FIG. 18 is a side sectional view showing an arm structure, and FIGS. 19 and 20 are side sectional views showing another example of a ring structure. 1 ... Chassis, 2 ... Tape guide drum, 3 ... Cassette, 6
…… Tape, 34 …… Cam, 34g …… Engagement groove, 34h …… Cam in groove, 74 …… Guide pin, 55,60,90,91 …… Arm.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuya Shigemura 1410 Inada, Katsuta City, Ibaraki Prefecture Inside the Tokai Plant, Hitachi Ltd. (72) Yoshiyuki Tanaka 1410 Inada, Katsuta City, Ibaraki Hitachi Tokai Co., Ltd. In-house (72) Inventor Yoshihiro Fukagawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Nippon Video Engineering Co., Ltd. (72) Inventor Masaki Uesugi 1410 Inada, Katsuta-shi, Ibaraki Hitachi Tokai Co., Ltd.

Claims (1)

[Claims] 1. A first cam portion formed on a first outer surface portion, a guide portion formed on a second outer surface portion, and a cam surface having a dimension lower than the height of the guide surface on the guide portion. A cam member having a formed second cam portion; a holding member that engages with the guide portion to hold the cam member; and a cam member that engages with the cam member to form the cam member. Driving means for driving along the guide portion, a first element that comes into contact with the first cam portion and is moved according to the shape of the first cam portion, and a second element that comes into contact with the second cam portion. And a second element that is moved according to the shape of the cam portion of, and a cam operating mechanism.