JP2006316895A - One-way intermittently feeding unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve accuracy of feed per stroke by eliminating variations occurring in the radius of each product of a ratchet wheel in a one-way intermittently feeding unit in which a one-way torque limiter is built in the ratchet wheel, and the inner wheel of the torque limiter is fixed in the housing. <P>SOLUTION: The position for fixing the inner wheel 3 with respect to the housing 4 is set by a positioning pin 29 so that the radial force F acting on the inner wheel 3 by means of the ratchet wheel 1 is received by a pillar part 26 between the pockets 8 in the inner wheel 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a one-way intermittent feed unit used as a feed unit in a component supply device such as an index table, and more particularly to an improvement in feed accuracy.

  As a usage example of the one-way intermittent feeding unit, a cover tape winding device for a component conveying member can be cited (Patent Document 1). In this case, the one-way intermittent feed unit has a structure in which a stopper lever is engaged with the ratchet wheel, and a ratchet pawl attached to the rotating plate is engaged with the ratchet wheel. Driven, the carrier tape is intermittently fed in a certain direction.

  The present invention also relates to a one-way intermittent feed unit in which a required torque is applied to the transport direction of a transported object such as a carrier tape, and a one-way clutch type torque limiter is incorporated in a ratchet wheel to prevent reverse rotation. Previously filed a patent application (Japanese Patent Application No. 2004-195508).

  In the application, the one-way clutch torque limiter 2 is incorporated on the inner diameter side of the ratchet wheel 1 as shown in FIGS. In the torque limiter 2, an inner ring 3 coaxial with the ratchet wheel 1 is housed in a recess 5 of the housing 4, and a mounting shaft 6 (see FIG. 9) provided on the back surface of the inner ring 3 is passed through the recess 5 and a nut. 7 is fixed to the housing 4. A required number of pockets 8 are formed on the outer diameter surface of the inner ring 3 at a predetermined interval in the circumferential direction, and between the cam surface 9 formed on the bottom surface of each pocket 8 and the inner diameter surface of the ratchet wheel 1. A wedge angle θ that is narrow in a certain direction is formed.

  A roller 11 and a spring 12 that urges the roller 11 in the direction of the wedge angle θ are accommodated in the pocket 8, and the ratchet wheel 1 rotates in the direction A in the direction opposite to the wedge angle θ with a required torque. Determine the direction. The front surface of the ratchet wheel 1 is covered with a boss portion 14 of a swing arm 13, and the boss portion 14 is swingably fitted to a shaft portion 15 provided on the front surface of the inner ring 3. The boss portion 14 is prevented from coming off by the screw 10 through the washer 16.

  A drive claw 18 is attached by a pin 17 at an eccentric position on the back surface of the boss portion 14 of the swing arm 13, and the drive claw 18 is engaged with a tooth 19 formed on the inner peripheral surface of the ratchet wheel 1. . The drive claw 18 is urged in a direction in which it is pressed against the teeth 19 by a spring 21 interposed between the drive claw 18 and the boss portion 14. A sprocket 22 is integrally provided on the outer diameter surface of the ratchet wheel 1.

When the swing arm 13 is swung in the direction of arrow a, the drive claw 18 meshes with the teeth 19 to rotate the ratchet wheel 1 in the direction of arrow A by a fixed pitch and the carrier tape is engaged with the sprocket 22. 23 is sent by one pitch. At this time, although the torque limiter 2 is idling, idling torque having a magnitude determined by the magnitude of the spring 12 and the wedge angle θ is generated. Conversely, when the swing arm 13 is swung in the direction of arrow b, the drive claw 18 slides on the teeth 19 and retracts by the same amount. At this time, when a force in the reverse rotation direction is applied to the ratchet wheel 1, the torque limiter 2 is locked to prevent the reverse rotation.
JP 2000-332490 A

  The one-way intermittent feeding unit described above is required to always feed a transported object such as the carrier tape 23 by the ratchet wheel 1, but in the conventional case, the outer diameter of the ratchet wheel 1 may change during rotation. Therefore, there is a problem that the feed amount changes.

  That is, in the conventional ratchet wheel 1, the position or posture in the circumferential direction of the inner ring 3 is not determined at the time of assembly, and varies depending on the product, so that a radial force F acts as shown in FIG. The load position may be a portion of the roller 11 or a so-called column portion 26 between the pockets 8 as shown in FIG. If the radius of the ratchet wheel 1 in the former case is R and the radius in the latter case is R ′, then R ≠ R ′ (generally R> R ′).

  Thus, in the prior art, since the position of the inner ring 3 in the circumferential direction at the time of assembling was not determined, the rotational circumferential length changed from product to product, which could cause variations in the feed amount.

  Accordingly, an object of the present invention is to eliminate the variation for each product and improve the accuracy of the feed amount by allowing the position when the inner ring 3 is assembled to be held constant.

  In order to solve the above-mentioned problems, the present invention provides a positioning means for the housing on the inner ring of the torque limiter described above.

  As the positioning means, a configuration in which a pin is inserted through the inner ring and the housing, a configuration in which a D-cut surface is formed in the concave / convex fitting portion between the inner ring and a part of the housing, and the like can be adopted.

  The relationship between the load position and the position of the inner ring is preferably determined so that the pillars between the pockets formed on the outer peripheral surface of the inner ring are at the load position.

  As described above, according to the present invention, in the one-way intermittent feed unit incorporating the inner ring fixed type one-way type torque limiter, the position or orientation of the inner ring with respect to the housing is determined for each product, and a radial force is applied. Since the relationship with the position is always constant, the ratchet wheel diameter does not change during operation. Thereby, feed accuracy is stabilized.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  The one-way intermittent feed unit of the first embodiment shown in FIGS. 1 to 3 has a one-way clutch type torque limiter 2 incorporated on the inner diameter side of the ratchet wheel 1 as in the conventional case described above. In the torque limiter 2, an inner ring 3 coaxial with the ratchet wheel 1 is accommodated in a recess 5 of a housing 4 and is fixed to the housing 4 with a screw 10. A required number of pockets 8 are formed on the outer diameter surface of the inner ring 3 at a predetermined interval in the circumferential direction, and between the cam surface 9 formed on the bottom surface of each pocket 8 and the inner diameter surface of the ratchet wheel 1. A wedge angle θ that is narrow in a certain direction is formed.

  A roller 11 and a spring 12 that urges the roller 11 in the direction of the wedge angle θ are accommodated in the pocket 8. Further, a direction A in which the ratchet wheel 1 idles with a required torque in a direction opposite to the wedge angle θ is determined as normal rotation. The front surface of the ratchet wheel 1 is covered with a boss portion 14 of a swing arm 13, and the boss portion 14 is swingably fitted to a central shaft portion 15 provided on the front surface of the inner ring 3. A flanged screw 10 passes through the boss portion 14 and the inner ring 3 and is fixed to the screw hole 20 at the center of the recess 5 of the housing 4 by screwing.

  A driving claw 18 attached to the back surface of the boss portion 14 is attached by a pin 17 at an eccentric position of the boss portion 14 of the swing arm 13, and the driving claw 18 is engaged with the teeth 19 on the inner peripheral surface of the ratchet wheel 1. Combined. The drive claw 18 is urged in a direction in which it is pressed against the teeth 19 by a spring 21 interposed between the drive claw 18 and the boss portion 14.

  As a positioning means for the inner ring 3, a positioning hole 27 penetrating from the front surface to the back surface is provided in a part of the inner ring 3, and a housing side positioning hole 28 corresponding to the positioning hole 27 is provided in the housing 4 (FIG. 2). The positioning pin 29 is inserted in a state where both the positioning holes 27 and 28 are matched, and the load position for receiving the radial force F is positioned so as to match the column portion 26.

  In the one-way intermittent feed unit of the first embodiment described above, when the swing arm 13 is swung in the direction of arrow a, the drive claw 18 meshes with the teeth 19 and the ratchet wheel 1 is rotated forward by a constant pitch (arrow). A), and the carrier tape 23 hung on the sprocket 22 of the ratchet wheel 1 is fed. At this time, although the torque limiter 2 is idling, an idling torque having a magnitude determined by the magnitude of the spring 12 and the wedge angle θ is generated. Conversely, when the swing arm 13 is swung in the direction of the arrow b, the drive claw 18 slides on the teeth 19 and retracts by the same amount. At this time, when a force in the reverse rotation direction is applied to the ratchet wheel 1, the torque limiter 2 is locked to prevent the reverse rotation.

  During the operation of the one-way intermittent feed unit as described above, the load position that receives the radial force F is determined by the column portion 26 of the inner ring 3 (see FIG. 1), so that the radius R of the ratchet wheel 1 is constant in any product. The feed accuracy is improved.

  Next, the structure of the second embodiment shown in FIGS. 4 to 6 is the same as that of the first embodiment described above except for the positioning means, so the description of the same parts is omitted. In this case, the positioning means is provided with a D-cut fitting concave portion 30 on the back surface of the inner ring 3, and a D-cut fitting convex portion 31 opposite to this is provided at the center of the concave portion 5 of the housing 4. The load position for receiving the radial force F can be determined in the column portion 26 of the inner ring 3 by fitting the fitting concave portion 30 and the fitting convex portion 31 (see FIG. 4). Accordingly, the radius R of the ratchet wheel 1 is constant in any product as in the case of the first embodiment.

Front view of the first embodiment Sectional view along line XX in FIG. Exploded perspective view Front view of the second embodiment Sectional view taken along line XX in FIG. Exploded perspective view Front view of conventional example (A) Operation explanatory diagram of FIG. 7, (b) Operation explanatory diagram of other states of FIG. Sectional view along line XX in FIG. Exploded perspective view

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ratchet wheel 2 Torque limiter 3 Inner ring 4 Housing 5 Recess 6 Mounting shaft part 7 Nut 8 Pocket 9 Cam surface 10 Screw 11 Roller 12 Spring 13 Swing arm 14 Boss part 15 Shaft part 16 Washer 17 Pin 18 Drive claw 19 Teeth 20 Screw Hole 21 Spring 22 Sprocket 23 Carrier tape 26 Column 27 Positioning hole 28 Housing side positioning hole 29 Positioning pin 30 Fitting recess 31 Fitting protrusion

Claims (4)

  A one-way clutch type torque limiter is incorporated on the inner diameter side of the ratchet wheel. An inner ring coaxial with the ratchet wheel is fixed to the housing, and the torque limiter has a predetermined interval in the circumferential direction on the outer diameter surface of the inner ring. A required number of pockets are formed, and a wedge angle that narrows in a certain direction is formed between the cam surface formed on the bottom surface of each pocket and the inner diameter surface of the ratchet wheel. An elastic body that biases in the direction of the wedge angle is housed, and a driving claw is attached to a swinging arm supported coaxially with the torque limiter. The driving claw is engaged with the ratchet wheel, and As the moving arm swings in a certain direction, the drive claw causes the ratchet wheel to idle in the direction opposite to the wedge angle with the required idling torque, and in the opposite direction to the above In the one-way intermittent feed unit in which the torque limiter is locked by swinging and the drive claw is retracted while preventing the reverse rotation of the ratchet wheel by the lock, positioning means for the housing is provided on the inner ring of the torque limiter. One-way intermittent feeding unit characterized by being provided.   2. The one-way intermittent feeding unit according to claim 1, wherein the positioning means is a pin inserted through the inner ring and the housing.   2. The one-way intermittent feeding unit according to claim 1, wherein the positioning means is a D-cut surface formed in a concave-convex fitting portion between the inner ring and a part of the housing.   The one-way intermittent feeding unit according to any one of claims 1 to 3, wherein the inner ring is positioned such that a column portion between pockets formed on the outer peripheral surface of the inner ring is at a load position.

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