JPH06171827A - Traverse device for thread - Google Patents

Abstract

PURPOSE:To prolong the life of a traverse guide by preventing the generation of the sudden acceleration of the traverse guide at turn portions, decreasing shock or the like, and decreasing the wear of the traverse guide. CONSTITUTION:In the case of a thread traverse device equipped with a reciprocation spiral cam groove that is formed at a rotatable traverse cam drum and whose both ends are turn portions, and a traverse guide that is engaged with the cam groove and conducts reciprocation slide by being guided with a guide rail, out of the inner and outer curves 21b, 22b of the turn portion cam groove 20, the inner side line 21b is formed with a cycloid curve, and sudden acceleration is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yarn traverse device, and more particularly to a traverse device which reduces the impact of a traverse guide which reciprocally slides in a cam groove formed in a traverse cam drum in the traverse device.

[0002]

2. Description of the Related Art In a take-up winder or the like, when a continuously fed yarn is wound on a bobbin, the yarn is traversed by a traverse device and wound. The yarn Y traverse device includes a reciprocating spiral cam groove formed on the surface of a rotatable traverse cam drum, the both ends of which are turn portions, and a reciprocating slide which engages with the cam groove and is guided by a guide rail. It is known to have a moving traverse guide.

An example thereof will be described with reference to FIG. 3 which is a cross-sectional view of the traverse device 7 and FIG. 4 which is a cross-sectional view taken along line XX of FIG. The traverse device 7 for the yarn Y is the drum case 5
A reciprocating spiral cam groove 1 formed on the surface of a traverse cam drum 2 which is rotatably attached to the cam rail 1 and has turn ends at both ends, and guide rails 3, 3'that engage with the cam groove 1
The traverse guide 4 is reciprocally slid by being guided by the upper and lower guide rails 3, 3.
While being guided in the axial direction of the traverse cam drum 2 by 3 ', the cam groove 1 of the traverse cam drum 2 is also provided.
, And reciprocating sliding within the winding traverse range L is repeated by the rotation of the traverse cam drum 2.

The shape of the traverse guide 4 in such a traverse device 7 will be described with reference to FIG. Figure 5 (a)
Is a side view, FIG. 5 (b) is a top view, and FIG. 5 (c) is a front view. This traverse guide 4 has a cam groove 1 on the base 8.
A resin molded product having a shape in which an engaging portion 9 for engaging with
A ceramic holding part 10 for holding the yarn Y is planted on the side opposite to the engaging part 9. The engaging portion 9 is shown in FIG.
When viewed from the front as shown in FIG. 6C, the linear portion 9a and the inclined portion 9b are fitted into the cam groove 1 and reciprocally slide along the cam groove 1 as the traverse cam drum rotates.

As shown in FIG. 6, the cam groove 1 of the traverse cam drum on which such a traverse guide 4 slides back and forth is formed by an inner line 11 and an outer line 12. The inner line 11 developed on the plane includes a straight line portion 11a and a curved portion 11b having a radius r1, and the outer line 12 developed on the plane includes a straight line portion 12a and a curved portion 12b having a radius r2. The curved portions 11b and 12b are determined as follows. First, the curved portion 11 having a desired radius r1
By determining b so that the straight line portion 11a becomes a tangent to the curved line portion 11b, the switching portions a and b of the straight line portion 11a and the curved line portion 11b are determined. By the way, since the engaging portion 9 of the traverse guide has the linear portion 9a, the radius of the curved portion 12b of the outer line 12 is the radius r1 of the curved portion 11b of the inner line 11.
+ If the width h of the engaging portion 9 of the traverse guide is set, the traverse guide cannot be turned. Therefore, the positions c and d of both ends of the engaging portion 9 are determined when the engaging portion 9 is located on the center line 13 of the traverse cam drum as shown by the solid line. Next, the engaging portion 9 in a state in which the engaging portion 9 is separated from the center line 13 of the traverse cam drum as shown by a chain double-dashed line
Determine the position e of the edge of. When the curved portion 12b having a radius r2 passing through the three positions c, d, and e is determined, the switching portions f and g in which the straight portion 12a is a tangent line are determined. The radius r2 of the curved portion 12b of the cam groove 1 thus determined is equal to the curved portion 1
It becomes smaller than the radius r1 of 1b, and the curved portion 12b has a shape that bulges outward.

The displacement curve of the inner line 11 of the cam groove 1 is shown in FIG. In the displacement curve, y represents the axial direction of the traverse cam drum 2, and the maximum length L is the traverse width. x represents the circumferential direction of the traverse cam drum 2, and the maximum length is nπφ. The curved portion 11b forming the first and last turn portions is an arc having a radius r1 and is tangentially connected to the straight portion 11a.

[0007]

However, since the turn portion of the cam groove of the traverse device described in the prior art is formed by a circular arc, the traverse guide moves at a constant velocity as shown in FIG. 7 (b). While the linear portion 11a has no acceleration, the curved portion 11b of the turn portion causes a rapid acceleration due to the centrifugal force, and the traverse in the turn portion of the cam groove is caused by the impact caused by the sudden acceleration. There is a problem that wear of the engaging portion of the guide increases. Further, as shown in FIG. 6, since the outer line 12 of the cam groove 1 is formed by an arc that bulges outward, the cam groove 1 extends from the engaging portion 9 of the solid line to the engaging portion 9 of the chain double-dashed line. There is also a problem that backlash is generated between the engagement portion 9 and the engagement portion 9, vibration is generated in combination with a sudden acceleration, and wear of the engagement portion 9 in the cam groove 1 is promoted.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to prevent the occurrence of rapid acceleration of the traverse guide at the turn portion and to prevent impact. It is an object of the present invention to provide a traverse device which can reduce the wear of the traverse guide and the life of the traverse guide by reducing the vibration and the vibration.

[0009]

In order to achieve the above object, the traverse device of the present invention comprises a reciprocating spiral cam groove formed in a rotatable traverse cam drum and having turn portions at both ends, and the cam groove. In a yarn traverse device provided with a traverse guide that engages and is guided by a guide rail to slide back and forth, one of the inner and outer curves of the cam groove of the turn portion is formed by a cycloid curve. . Further, it is preferable that either the inner or outer curve of the cam groove of the turn portion is formed by the envelope drawn by the engaging portion when the traverse guide is turned.

[0010]

If any one of the inner and outer curves of the cam groove of the turn portion is a cycloid curve, the generation of acceleration at the turn portion of the traverse guide becomes gentle, and the impact due to the generation of acceleration is reduced. If either the inner or outer curve of the cam groove of the turn portion is the envelope drawn by the engaging portion when the traverse guide is turned, the backlash of the traverse at the turn portion is eliminated, and vibration is reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a turn portion of a cam groove 22 of the traverse device of the present invention, and FIG.
2 is a displacement curve of FIG. 1, and FIG. 2 (b) is a diagram showing a change in acceleration of FIG. 2 (a).

Cam groove 2 of the traverse cam drum of the present invention
0 is formed by an inner line 21 and an outer line 22. The inner line 21 developed on the plane is composed of a straight portion 21a and a curved portion 21b of a cycloid curve, and the outer line 22 developed on the plane is a curved portion 22b of the envelope drawn by the straight portion 22a and the engaging portion 9 of the traverse guide. It consists of This curved part 2
A turn portion is formed by 1b and 22b.

The equation for obtaining the cycloid curve which is the curve I on the inner side wall (right side of the figure) will be briefly described with reference to FIG. FIG. 2A is a diagram showing a displacement curve of a side wall inside the cam groove 20, and FIG. 2B is a diagram showing acceleration of the displacement curve of FIG. 2A. In FIG. 2A, y represents the axial direction of the traverse cam drum 2, and the maximum length is the traverse width L. x is traverse cam drum 2
In the circumferential direction, and the maximum length is nπφ. J is x
Direction turn part length, K is the y direction turn part length,
tan α is the slope. The inclination tan α of the straight line portion is a constant value determined in advance so that the yarn is not loosened at the turn portion.

The curve I of the turn portion is I = K [1-cos (πx / 2J)]. The above formula is d ² I / dx ² = (Kπ ² / 4J ² ) cos (πx / 2
In J), the cycloid condition is satisfied. Also, the curve I is x = J and must be connected to the straight line portion, so x =
The slopes tan α at J are equal. The slope tan α of the curve I is tan α = dI / dx = (Kπ / 2J) sin (πx / 2J) ... Equation 1 Then, since x = J, K becomes K = (2J · tan α) / π ... On the other hand, the slope tan α of the straight line portion is tan α = (L−2K) / (nπφ−2J) ... Equation 3 from the graph, so that J is J = [(nπφ · tan α-L) π] / [2 (π-2)
tan α]. Here, by substituting the numerical values of n, φ, L, and tanα, the specific numerical values of J and K are obtained, and these are substituted into the equation of the curve I, I = K [1-cos (πx / 2J)] , Get the cycloid curve.

When the inner line I of the turn portion is determined on the basis of the cycloid curve thus obtained, FIG.
As shown in, the acceleration is 0 at the joint j with the straight line portion, gradually increases / decreases, and becomes 0 again at M where the direction changes. Therefore, the acceleration rapidly increases in a stepwise manner as in the conventional case. Unlike, the impact due to the acceleration generated at the turn part is reduced.

Next, returning to FIG. 1, how to determine the curve H of the outer line 22 will be described. The curve I, which is a cycloid curve, is divided into small line segments, and a point G ′ on the center line in the width direction (transverse direction) passing through the center of gravity G of the traverse guide 4 of the engaging portion 9 is always in contact with the curve I, and the engaging portion The locus of the envelope of the engaging portion 9 when the straight line portion 9a of 9 is moved so as to face the tangential direction with respect to the small line segment of the curve I is described by CAD or the like for each small line segment, and A large number of C / D points, which are the C / D loci of the engaging portion 9, are connected. When the curve H of the outer side wall is determined in this manner, the center of gravity G of the traverse guide 4 travels so as to draw a cycloid curve, and the amount of backlash is minimized and vibration is reduced. An extremely small gap is provided between the traverse guide 4 and the cam groove 20 due to dimensional tolerance.

The cam groove 2 of the turn portion thus obtained
When the traverse guide 4 moves along 0, the generation of acceleration at the turn portion of the traverse guide is gentle, and the resulting impact is small. Further, since the center of gravity G of the traverse guide 4 is moved so as to draw a cycloid curve to minimize play, vibration is also small. As a result, the traverse guide is less worn, and the interval between the traverse cam replacement days becomes longer.

In the above-mentioned cam groove 20, the inner line 21 of the turn portion has a cycloid curve, but the outer line 22 may have a cycloid curve. In this case, the inner line 21
Divides the cycloid curve that is the outer line 22 into small sections, and moves the G ′ point of the engaging part 9 when the points C and D of the engaging part 9 move along the cycloid curve that is the outer line 22. The locus of the envelope curve is plotted for each of the small sections, and a curve is formed by connecting a number of G'points, which is the locus of the envelope curve of the G'point of the engaging portion 9. When the inner line 21 is determined in this manner, the center of gravity G of the traverse guide 4 moves so as to draw a cycloid curve, so that not only the shock due to the acceleration generation but also the backlash and the vibration are reduced. Further, in the above embodiment, the points to be plotted are two points C and D, but in this case, only one point is plotted at G ', so it is easy to determine the curve.

[0019]

According to the yarn traverse device of the present invention, one of the inner and outer curves of the cam groove of the turn portion is formed by a cycloid curve, and the generation of acceleration at the turn portion of the traverse guide is gentle. Since the impact caused by the acceleration is reduced, the wear of the traverse guide is reduced and the replacement period is extended. If either of the inner and outer curves of the cam groove of the turn part is formed by the envelope drawn by the engaging part when the traverse guide turns, there will be no rattling of the traverse guide at the turn part, vibration will be reduced, and acceleration relaxation The traverse guide wear is further reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a turn portion of a cam groove of a traverse device of the present invention.

FIG. 2 is a diagram showing a displacement curve of a cam groove and a change in acceleration.

FIG. 3 is a diagram showing a traverse device.

FIG. 4 is a sectional view taken along line XX of FIG.

FIG. 5 is a diagram showing a traverse guide that slides back and forth in a cam groove.

FIG. 6 is a view showing a turn portion of a cam groove of a conventional traverse device.

FIG. 7 is a diagram showing a displacement curve and a change in acceleration of a cam groove in a conventional traverse device.

[Explanation of symbols]

 3 Guide Rail 4 Traverse Guide 7 Traverse Device 9 Traverse Guide Engagement 20 Cam Groove 21 Inner Line 22 Outer Line H Outer Line Curve (Envelope) I Inner Line Curve (Cycloid Curve)

Claims (2)

[Claims] 1. A reciprocating spiral cam groove formed on a rotatable traverse cam drum and having turn portions at both ends, and a traverse guide engaged with the cam groove and reciprocally slid by being guided by a guide rail. In the yarn traverse device, one of the inner and outer curves of the cam groove of the turn portion is formed by a cycloid curve, the yarn traverse device. 2. The yarn traverse device according to claim 1, wherein either one of the inner and outer curves of the cam groove of the turn portion is formed by an envelope drawn by the engaging portion when the traverse guide is turned.