JPS6134020B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a Geneva mechanism that intermittently rotates a driven rotor by constant speed rotation of a driving rotor. The present invention relates to a technique for preventing a Geneva mechanism from malfunctioning or falling into an inoperable state.

BACKGROUND TECHNOLOGY As shown in FIGS. 1 and 2, a device conventionally known as a Geneva mechanism has a driving wheel (driving rotating body) equipped with a locking wheel 2 at the center and a drive pin 3 at the periphery. 1, a plurality of radial grooves 4 that engage with the drive pin 3, and an arcuate notch 5 that contacts the outer peripheral surface of the locking wheel 2 between the adjacent radial grooves 4, 4. (driven rotating body) 6. As shown in the figure, the driving pin 3 and the radial groove 4 are engaged by combining the driving wheel 1 and the driven wheel 6 so that they partially overlap when viewed from a direction parallel to their rotation center lines. The rotational motion of the prime mover 1 is transmitted to the driven wheel 6, and after the drive pin 3 is separated from the radial groove 4, the locking wheel 2 and the arcuate notch 5
Due to the engagement with the driven wheel 6, the rotational movement of the driven wheel 6 is prevented despite the rotation of the prime mover 1.

However, when the drive pin 3 is at the position of the pin 3a just before it starts to enter the radial groove 4 as the motive wheel 1 rotates in the direction of the arrow T, the end 8 of the outer peripheral surface 7 of the locking wheel 2 Because it is extremely close to the intersection point A between the straight line XX connecting the centers of 1 and 6 and the partial cylindrical concave surface defining the arcuate notch 5, there is also a slight gap between the outer circumferential surface 7 and the arcuate notch 5. When an external force in the direction of arrow P is applied to the driven wheel 6 due to the existence of the gap, the concave surface of the arc-shaped notch 5 rotates in a direction away from the outer peripheral surface 7 of the locking wheel 2 (excessive forward rotation). Therefore,
The drive pin 3 cannot engage with the radial groove 4, collides with the vicinity of the entrance of the radial groove 4, generates abnormal noise, and in severe cases becomes inoperable.

On the other hand, when the drive pin 3 that has entered the radial groove 4 is at the position of the pin 3b immediately after leaving the radial groove 4 as shown in FIG. is the said straight line XX
Since it is very close to the intersection A between the curved surface and the concave surface of the partial cylinder defining the arcuate notch 5, when an external force in the direction of arrow Q is applied to the driven rotary body 6, the driven wheel 6 is rotated so that the concave surface of the arcuate notch 5 is a locking wheel. 2, that is, in the opposite direction, and both cars 1 and 6
This will prevent the smooth rotation of the motor.

An intermittent rotation mechanism that does not have such drawbacks is described in Japanese Patent Application Laid-Open No. 53-5473. This is the 9th
As shown in FIG.
An arcuate locking guide groove 104 is provided on both sides of the rotating body 100, and a driving rod 110 and a locking rod 112 are provided with a driving roller 106 and a locking roller 108 that can be engaged with the grooves 102 and 104, respectively. A drive shaft 116 provided at a position remote from the driven shaft 114
and when the driving roller 106 is engaged with the driven guide groove 102, the locking roller 108 is disengaged from the locking guide groove 104, and the driven guide groove 102
The driven guide groove 102, the locking guide groove 104,
The relative positions of the drive roller 106 and the locking roller 108 are determined.

In this intermittent rotation mechanism, the drive roller 10
6 engages with the driven guide groove 102 and the driving rod 110 rotates the rotating body 100, the locking roller 108
is detached from the locking guide groove 104 and allows rotation of the rotating body 100, and when the driving roller 106 is detached from the driven guide groove 102, the locking roller 1
08 engages with the locking guide groove 104 and the rotating body 100
prevent rotation. Therefore, this intermittent rotation mechanism does not have the drawbacks of the excessive forward rotation and reverse rotation in the conventional Geneva mechanism.

Problems to be solved by the invention However, in this intermittent rotation mechanism,
As is clear from FIG. 9, the driven guide groove 102 and the locking guide groove 104 are provided in the same plane, and the driving roller 106 and the locking roller 108 are configured to rotate in the same plane. rotating body 100
The drive roller 106 may interfere with the portion of the rotating body 100 that forms the locking guide groove 104, or the locking roller 108 may interfere with the portion of the rotating body 100 that forms the locking guide groove 104.
Two locking guide grooves 104 are provided on both sides of each driven guide groove 102 in order to avoid interference with the portion forming the driven guide groove 102 of 00. That is, the relative positions of the driven guide groove 102 and the locking guide groove 104 are devised so that the above-mentioned interference can be avoided within one plane, and the structure of the intermittent rotation mechanism is therefore complicated. It cannot be avoided.

An object of the present invention is to prevent excessive forward rotation or reverse rotation due to external force of the driven rotating body of the Geneva mechanism, while avoiding such complication of the structure as much as possible.

Means for Solving the Problems To solve this problem, the present invention provides a driven rotating body having at least one circular arc notch defined by a radial groove opening radially outward and a partial cylinder concave surface;
A driving rotating body that is disposed such that at least a portion thereof overlaps the driven rotating body when viewed from a direction parallel to the rotational center line of the driven rotating body, and is provided with a rocking wheel and a drive pin on a surface on the side of the driven rotating body. The rotational motion of the driving rotor is transmitted to the driven rotor by the engagement between the drive pin and the radial groove, and after the drive pin is disengaged from the radial groove, the locking wheel and the circular notch are engaged. In the Geneva mechanism in which the rotational movement of the driven rotary body is prevented regardless of the rotation of the driving rotary body by An engaging protrusion extending toward the driving rotating body and having a partial cylindrical convex surface concentric with a partial cylindrical concave surface defining an arcuate notch is provided on the forming part, while the driving pin is provided on the driving rotating body. is provided with an engagement pin that engages with the partial cylindrical convex surface of the engagement protrusion in a state where the radial groove is located at the opening side end of the radial groove, and the amount of protrusion of the engagement pin from the driving rotating body is determined by the protrusion of the drive pin. By making the drive pin smaller than the amount, the drive pin can be engaged with the radial groove, but the engagement pin is not engaged.

Function In the Geneva mechanism configured in this way,
At least one of excessive forward rotation and excessive reverse rotation of the driven rotating body is prevented by the engagement between the engagement pin and the engagement protrusion. Moreover, on the driving rotating body side, the amount of protrusion of the engagement pin from the driving rotating body is made smaller than that of the drive pin, and on the driven rotating body side, the forming position of the partial cylindrical convex surface that engages with the engaging pin and the guide groove is set to the driven rotating body side. Since they are offset from each other in the direction of the rotational center line of the rotating body, they can be engaged with the drive pin guide groove, but although the engagement pin three-dimensionally intersects with the guide groove during the movement process, There is no actual interference with the driven rotating body forming the guide groove. In other words, interference between the two is avoided by adjusting the three-dimensional relative positions.

Effects of the Invention As a result, in the intermittent rotation mechanism according to the present invention, the driven rotating body can be made simpler and smaller in structure compared to the rotating body 100 shown in FIGS. 9 and 10, As a result, an ideal intermittent rotation mechanism that is inexpensive and prevents the driven rotor from rotating excessively in the forward or reverse direction due to external force has been obtained.

Embodiment Hereinafter, a Geneva mechanism as an embodiment of the present invention will be described in detail based on the drawings.

First, in the Geneva mechanism shown in FIGS. 3 and 4, a driving wheel (driving rotating body) 1 equipped with a locking wheel 2 and a drive pin 3 has six radial grooves 4A, 4.
B…, 4F and six arcuate notches 5A, 5B…5F
It is combined with a driven wheel (driven rotary body) 6 having the following. The locking wheel 2 is a circular wheel centered around the rotation center of the motive wheel 1, and is provided with a cutout in a portion thereof to allow the rotation of the driven wheel 6. The arcuate notches 5A,..., 5F have a shape surrounded by a partially arcuate concave surface that can just slide into contact with the outer peripheral surface of the locking wheel 2, and the radial grooves 4A...4F have the arcuate notches 5A...5F as the locking wheels. The drive pin 3 is formed to open outward in the radial direction so as to coincide with the direction of the tangent to the rotation locus drawn by the drive pin 3 when the motor vehicle 1 rotates while being engaged with the drive pin 2 .

In the portion of the driven wheel 6 sandwiched between the adjacent radial grooves 4A and 4B, there is an arc-shaped protrusion ₁₂ centered on the center O1 of the locking wheel 2 along the arc-shaped notch 5.
A (engaging protrusion) (see Figure 5) is formed.
And a straight line X connecting the center O ₁ and O ₂ of the driven vehicle
-X, the engagement pin 13 is provided on the motive wheel 1 at a position symmetrical to the position at the moment when the drive pin 3 enters the radial groove 4B. This engagement pin 1
3 and the drive pin 3 are equidistant from the center O ₁ , and are 60 degrees each on the left and right with respect to the straight line X-X.
It is arranged at a degree angle. Moreover, the engagement pin 13
It is formed so as to be in sliding contact with a partially cylindrical convex surface on the outer periphery of the strip 12A. Note that the arrangement angle of both pins 3 and 13 is made slightly smaller than 60 degrees, and after the drive pin 3 enters the radial groove 4B by a small amount, the engagement pin 1
3 may be separated from the protrusion 12.

Furthermore, as shown in FIG. 4, an arc-shaped protrusion 12B is similarly provided on the portion of the driven wheel 6 that is sandwiched between the radial groove 4B and another radial groove 4C adjacent thereto, so that the straight line The engagement pin 23 is provided on the motive wheel 1 at a position symmetrical to the position at the moment when the drive pin 3 leaves the radial groove 4B with respect to XX.
In this case as well, the engagement pin 23 and the drive pin 3 are located at the same distance from the center O ₁ and are arranged at an angle of 60 degrees to the left and right with respect to the straight line XX, and the engagement pin 23 is protruded. It is formed so as to be in sliding contact with the outer periphery of the strip 12B.

In the device configured in this way, the motive wheel 1 rotates in the direction of arrow T as shown in FIG. For example, when the vehicle is at the pin position 3a shown by the two-dot chain line, just before starting to enter the
The engagement pin 13 is located at the position indicated by 13a (arc-shaped notch 5
A) and is engaged with the protrusion 12A near the end opposite to the side closer to the radial groove 4B. In this state, when an external force is applied to the driven wheel 6 in the direction of the arrow P, the protrusion 12A comes into contact with the engagement pin 13 at the pin position 13a, causing the driven wheel 6 to rotate excessively in the forward direction of the arrow P. be prevented. As a result, the drive pin 3 is smoothly fitted into the radial groove 4B,
Unlike the conventional example, there is no possibility that the drive pin 3 will collide with the vicinity of the entrance of the radial groove 4 and the Geneva device will become inoperable.

Moreover, even if the drive pin 3 enters the radial groove 4B, the driven wheel 6 hardly rotates immediately after entering, because the radial groove 4B is formed in the direction tangent to the rotation locus of the drive pin 3. Since the motor vehicle 1 is rotating at a constant speed, the engagement pin 13 quickly moves away from the protrusion 12A, which is almost stationary, after the drive pin 3 enters the radial groove 4B.
The normal rotation of the driven wheel 6 is not hindered.

On the other hand, the live pin 3 that has advanced to the radial groove 4B is in the fourth position.
As shown in the figure, at the moment of separation from the radial groove 4B, the engagement pin 23 starts to engage with the protrusion 12B, so even if an external force is applied to the driven wheel 6 in the direction of the arrow Q in this state, the driven wheel 6 does not rotate in the opposite direction in the direction of arrow Q, and there is no possibility that the smooth Geneva motion as in the conventional example will be impaired.

Note that the external force applied to the driven vehicle 6 is in the P direction (Fig. 3) when the drive pin 3 enters, and in the Q direction when the drive pin 3 leaves.
direction (Fig. 4), the number of engaging pins is two (1).
3, 23 If only the necessary external force in one direction is applied, it is sufficient to install one of the engagement pins. In addition, the protrusions 12A, 12B, ... are also used for the engagement pin 1 when the drive pin 3 enters or leaves the drive pin 3.
Only the portion near 3 or 23 is necessary, and the portions further away from this are not necessarily necessary.

Although the specific example illustrated above is the most preferable example for implementing the present invention, the present invention is not limited thereto in any way, and may be implemented with various modifications and improvements based on the knowledge of those skilled in the art. It's something you get.

For example, the drive pin 3 and the engagement pins 13, 2
In order to reduce the frictional resistance between the drive pin 3 and the radial groove 4A, etc., and the protrusion 12A, etc., a pin with a roller can be used in place of the drive pin 3 and the engagement pins 13, 23 in the above-mentioned embodiment. It is.

In addition, although the driven wheel 6 has been described as having six sets of radial grooves and arcuate notches, if the prime mover 1 rotates more than once, it is sufficient to have three or more sets of radial grooves and arcuate notches. Also, the driving rotating body does not rotate once,
When rotating in both forward and reverse directions within a limited angular range, a pair of radial grooves 4, arcuate notches 5 and The effects of the present invention can be obtained by combining a driven rotating body having one arcuate protrusion 16.

Furthermore, in the above embodiment, the drive pin 3
At the moment when the drive pin 3 and the engagement pin 13 enter the radial groove 4B, the drive pin 3 and the engagement pin 13 were in symmetrical positions with respect to the straight line XX, but as shown in FIGS. 7 and 8, an asymmetrical position is also possible It is. That is, in FIG. 7, the center distances r1 and r2 between the drive pin 3, the engagement pin 53, and the locking wheel 2 are r
1>r2, and in FIG. 8, the drive pin 3 and the engagement pin 63 are at an angle of θ with respect to the straight line XX.
Although there is a relationship of ₁ > θ ₂ and r1 < r2, the effects of the present invention can be obtained in both cases.

[Brief explanation of the drawing]

FIG. 1 is a front view of a conventional Geneva mechanism, showing the moment when the drive pin enters the radial groove, and FIG. 2 also shows the moment when it leaves. FIG. 3 is a front view of the Geneva mechanism as an embodiment of the present invention, showing the moment when the drive pin enters the radial groove, and FIG. 4 similarly showing the moment when it leaves. FIG. 5 is a cross section taken along the line VV in FIG. 3. FIGS. 6 to 8 are front views showing other embodiments of the present invention. FIG. 9 is a side view showing an example of a conventional intermittent rotation device, and FIG. 10 is a sectional view taken along line XX in FIG. 1: Motive wheel (power rotating body), 2: Locking wheel, 3: Drive pin, 4A, 4B,...4
F; 4: Radial groove, 5A, 5B,...5F; 5: Arc-shaped notch, 6: Driven wheel (driven rotating body), 12A, 1
2B; 16: Arc-shaped protrusion (engaging protrusion), 13, 2
3, 43, 53, 63: Engagement pin.

Claims (1)

[Claims] 1. Radial grooves 4A, 4B that open outward in the radial direction;
4C, 4D, 4F; 4 and arcuate cutouts 5A, 5B, 5C, 5D defined by partial cylindrical concave surfaces;
5F; a driven rotary body 6 having at least one 5; the driven rotary body is disposed such that at least a portion overlaps with the driven rotary body when viewed from a direction parallel to the rotation center line of the driven rotary body; It includes a driving rotating body 1 having a locking wheel 2 and a drive pin 3 on its body side surface, and the rotational motion of the driving rotating body is transmitted to the driven rotating body by the engagement of the drive pin and the radial groove, and the drive pin In the Geneva mechanism, the driven rotary body is prevented from rotating despite the rotation of the driving rotary body by the engagement between the locking wheel and the circular notch after the rotation of the driven rotary body is removed from the radial groove. At least a portion near the end of the notch opposite to the side close to the radial groove extends toward the driving rotating body, and
Engagement protrusions 12A, 12 having a partial cylindrical convex surface concentric with the partial cylindrical concave surface defining the arcuate notch;
B; 16 is provided, and the engagement pins 13, 23; 43 engage with the partial cylindrical convex surface of the engagement protrusion in a state where the drive pin is located at the opening side end of the radial groove on the driving rotating body; 53; 63, and by making the amount of protrusion of the engagement pin from the driving rotating body smaller than the amount of protrusion of the drive pin,
The Geneva mechanism is characterized in that the drive pin is capable of engaging with the radial groove, but the engagement pin is not engaged with the radial groove.