JPS6224127Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention mainly relates to a cam device most suitable for a function switching mechanism of a tape recorder or the like.

[Conventional technology]

In tape decks, etc., which enable regular recording and playback operations even when the tape running direction is reversed, each function such as recording, playback, fast forward, rewind, and stop is used as a switching mechanism to reverse the tape running direction. Accordingly, by taking advantage of the fact that the rotational direction of the reel stand is also reversed, the cam device that rotates in relation to the rotation of the reel stand is provided with the plurality of functions described above, and the functions are changed depending on the rotational direction of the cam device. There was something to change.

For example, multiple functions such as crimping the pinch roller, moving the head stand up and down, rotating the head, crimping the idler, and operating the leaf switch can be performed using a single cam body and multiple cam surfaces formed on the cam body. There is a cam device equipped with an engageable pin, and the cam device is shown in the plan view of FIG. 1, the second enlarged perspective view of the main part, and the third enlarged plan view of the main part. still,
Components having the same effect are indicated by the same reference numerals throughout the drawings.

First, the configuration of each part will be explained.

In FIGS. 1, 2, and 3, 1 is a cam body, and 2 is an inclined surface formed by cutting and raising a part of the cam body 1, and capable of maintaining an inclined surface of a predetermined height by elastic force. Department. Reference numeral 10 denotes a first protrusion, which is formed over substantially the entire circumference of the cam body 1 and constitutes a first cam surface 11 . 20 is a second protrusion, and like the protrusion 10, it constitutes a second cam surface 22. 9 is a groove existing between the protrusion 10 and the protrusion 20. The inclined portion 2 is formed by cutting and raising the bottom of the groove 9, and a third cam surface 33 is formed at the tip of the inclined portion 2 and on the outer peripheral side of the cam body 1. Further, the inclined portion 2 has a valve function that allows the pin to pass only in the direction from the base to the tip.

Incidentally, when the inclined portion 2 is cut and raised from the groove 9, a cut and raised hole 8 and a gap 4 are created. 5
and 6 are gaps generated between the inclined portion 2 and the first cam surface 11 and the second cam surface 22,
The thickness is 0.5 mm or more for convenience of mold production.

3 is a pin that is guided by the cam surfaces 11, 22, and 33 and performs a cam operation.

Next, the operation will be explained. The cam body 1 rotates, and the cam surfaces 11, 22, 3 move the pin 3 in a substantially radial direction from the center of rotation.
3 guides the pin 3.

Naturally, the rotating member is the cam body 1,
Not the pin 3 mentioned above. However, for convenience of explanation on the drawings, the cam body 1 is kept stationary and the pin 3 is
It is explained as if it were being rotated along the cam surfaces 11, 22, and 33.

In each drawing, the top of the slope 2 is
When the pin 3 moves from the base to the tip (direction A in the figure), the pin 3 pushes the inclined part 2 in the direction D in the figure while pushing the cam surface 1
1, and advances on the cam surface 11 in a direction opposite to the direction B in the drawing.

As shown in FIG. 3, the pin 3 is guided by the cam surface 11 and advances in the direction of arrow B, and after passing through the cam surface 33, the pin 3 moves toward the cam surface 22.
Consider a series of actions that progress along the way.

When the pin 3 is guided by the cam surface 11 and moves from the direction of arrow B, there is a risk that it will enter the gap 5 of the inclined portion 2. Furthermore, even if the pin 3 could move in the direction of arrow C while contacting the cam surface 33 formed at the tip of the inclined part 2, the inclined part 2 would be undesirably deflected as shown by the dotted line. occurs, and the gap 6 widens. Further, a step is created between the cam surface 33 and the cam surface 22, and the pin 3 tends to enter the gap 6.

[Problem that the invention attempts to solve]

As mentioned above, the pin 3 is connected to the gaps 5 and 6.
It goes without saying that the original operation of this cam device will be lost if the pin 3
Even if the pin 3 does not enter the gaps 5 and 6, the pin 3 may get stuck in the gaps 5 and 6, and smooth operation cannot be expected.

The present invention was made in order to eliminate the drawbacks of the conventional ones as described above.
It is an object of the present invention to provide a cam device in which smooth operation can be obtained by forming the tip of the inclined portion 2 so as to narrow the cams.

[Means for solving problems]

In order to solve this problem, in the present invention, in the groove 9 existing between the protrusion 10 and the protrusion 20, when forming the inclined part 2 by cutting and raising the bottom of the groove 9, The groove 9 is formed at the tip of the inclined portion 2.
A bulge was formed to increase the distance in the width direction.

[Effect]

Since the gaps 5 and 6 are narrowed by the bulges 15 and 16, even if the pin 3 approaches the gaps 5 and 6, it does not enter. Moreover, the amount of undesired deflection as shown by the dotted line in FIG. 3 is also limited at the same time.

〔Example〕

An embodiment of the present invention will be described with reference to FIG.
In FIG. 4, reference numeral 2' denotes an inclined portion having bulges 15 and 16 formed at the tip thereof to increase the distance in the width direction of the groove 9. Since the bulging portion 15 narrows the gap 5, the pin 3 narrows the gap 5.
Even when passing in the direction of arrow B while contacting the pin 3, the gap 5 is much larger than the diameter of the pin 3.
Since it is smaller, it does not adversely affect the smooth cam movement of the pin 3.

Next, the pin 3 contacts the cam surface 33,
When being guided, the pin 3 acts to bend the inclined portion 2' into the shape shown by the dotted line in FIG. 4, but unlike the conventional example shown in FIG. 3, the gap 5 is small. The amount of deflection mentioned above also decreases as the temperature increases. Therefore, the gap 6 that widens when the deflection occurs does not become larger than in the conventional example. Furthermore, the gap 6 is also tightly fitted due to the bulge 16. Therefore, even when the pin 3 moves from the cam surface 33 to the cam surface 22, it can continue its operation smoothly.

〔effect〕

The present invention includes a rotatable cam body 1 having a cam surface, and a guided pin that is guided by the cam surface by the rotation of the cam body 1 and moves on a substantially straight line passing approximately through the center of the rotation. 3, and the cam surface has a first cam surface 11, a second cam surface 22, and a third cam surface 11.
Of these cam surfaces, the first cam surface 11 and the second cam surface 22 are formed by a first cam surface 33 that protrudes along the axial direction of the rotation in the plane of the cam body 1. 1 protrusion 10 and second protrusion 20
The same side of each wall surface along the approximate circumference of the cam body (both peripheral surfaces are either the outer peripheral surface or the inner peripheral surface)
The cam body 1 is formed by a wall surface of
A groove 9 through which the pin 3 can pass is formed by a predetermined portion of the first protrusion 10 and the second protrusion 20, and the bottom of the groove 9 is inclined to pass through the groove 9. The third cam surface 33 has a shape that rises up to the point where the pin 3 makes sufficient contact with it, and also has an inclined part 2 which elastically maintains this shape. When the cam body 1 is rotated in the direction from the base of the inclined portion 2 to the tip thereof, the pin 3 on the first cam surface 11 passes through the groove 9. The cam body 1 is guided only by the first cam surface 11 as shown in FIG. In the case where the inside of the groove 9
In a cam device in which the pin 3 on the first cam surface 11 other than the first cam surface 11 is guided by the third cam surface 33 and does not reach the groove 9 but reaches the second cam surface 22, the above-mentioned slope At the tip of part 2,
Since the bulging portions 15 and 16 are formed such that the distance in the width direction of the groove 9 at the tip portion is longer than that at the base portion of the inclined portion 2, the cam surfaces 11 and 2
The movement of the pins that move 2 and 33 can be made smooth.

[Brief explanation of the drawing]

Figures 1, 2, and 3 show a conventional example, where Figure 1 is a plan view, Figure 2 is an enlarged perspective view of the main part,
FIG. 3 is an enlarged plan view of the main part. FIG. 4 is an enlarged plan view showing one embodiment of the present invention. 1: Cam body, 2, 2': Inclined part, 3: Pin,
4, 5, 6: Gap, 8: Cut-up hole, 9:
groove, 10: first protrusion, 11: first cam surface, 1
5, 16: bulge, 20: second protrusion, 22: second cam surface, 33: third cam surface.

Claims (1)

[Scope of utility model registration request] It has a rotatable cam body having a cam surface, and a guided pin that is guided by the cam surface as the cam body rotates and moves on a substantially straight line passing approximately at the center of the rotation, and the cam surface consists of a first cam surface, a second cam surface, and a third cam surface, and among these cam surfaces, the first cam surface and the second cam surface are:
a first protrusion and a second protrusion that protrude along the axial direction of the rotation in the plane of the cam body;
The cam body is formed by a wall surface of the same side peripheral surface among the separate wall surfaces along the approximate circumference of the cam body, and the cam body has:
a groove through which the pin can pass, formed by a predetermined portion of the first protrusion and the second protrusion;
The bottom of the groove is inclined and rises up to the point where the pin passing through the groove comes into sufficient contact with the groove, and the groove has an inclined part in which this shape is elastically maintained, and the tip of the inclined part The third cam surface is formed by the pin on the first cam surface, and when the cam body is rotated in the direction from the base to the tip of the slope, the pin moves through the groove. guided only by the first cam surface to pass;
Further, when the cam body is rotated in a direction in which the pin on the first cam surface extends from the tip side to the base side of the inclined portion, the pin on the first cam surface excluding the inside of the groove is guided by a third cam surface and does not reach the groove, but reaches the second cam surface. A cam device characterized in that a bulge portion is formed at the tip portion so that the distance in the width direction of the groove is increased.