JP4139208B2 - Cap tightening machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cap tightening machine used when a cap is tightened to an open end of a container or the like.
[0002]
[Prior art]
[Patent Literature]
In order to close the opening of the container, a screw-type cap is widely used. Conventionally, various cap fastening machines are used for fastening the cap to the container, so-called capping. A typical example is a capping device disclosed in the patent literature. This capping device is configured to hold a cap on a chuck provided at the tip and tighten the held cap on the opening of the container by rotating the chuck. The chuck includes a magnet for holding the cap by suction and an annular chuck rubber that presses against the outer peripheral surface of the cap and holds the cap.
[0003]
When capping, first, the cap is temporarily tightened by engaging the cap with the opening of the container while the cap is attracted and held by the magnet of the chuck and rotating the chuck. When the cap is tightened until it slips with the magnet in this way, the chuck rubber is then pressed so as to come into pressure contact with the cap, and the cap is further tightened by applying further torque to the cap by the frictional resistance caused by the pressure contact of the chuck rubber.
[0004]
[Problems to be solved by the invention]
The conventional capping device has a structure in which the chuck rubber is pressed against the cap to transmit the rotation, and thus problems such as a complicated mechanism and control for operating the chuck rubber have occurred. In addition, when the cap is temporarily tightened, the cap is temporarily tightened using a means other than the chuck rubber used for the final additional tightening, such as a magnet or vacuum. Problems such as complications occurred. Further, since the chuck rubber is rubber, there has been a problem that the holding force is easily lowered due to deterioration in a short period of time, and frequent maintenance is required.
[0005]
[Means for Solving the Problems]
The present invention has been created in view of the above-described problems, and is capable of rotating integrally with the first member that can rotate by receiving rotation transmission, and rotatable with respect to the first member. And a coil spring provided by connecting the first member and the second member, and the coil spring is fitted and held with a cap that is tightened to an inner diameter portion thereof. One end of which is connected to the first member and the other end is connected to the second member, respectively, according to the differential angle when the first member and the second member are rotating. The diameter is reduced or enlarged . The second member is preferably supported via a one-way clutch so that it can rotate in one direction with respect to the first member and cannot rotate in the other direction.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 7, reference numeral 1 denotes a cap fastening machine, which includes an air slide mechanism 3 attached to a movable frame 2 of a robot, and a tool unit 4 connected to the air slide mechanism 3.
[0007]
The air slide mechanism 3 includes a slide portion 3a that expands and contracts in the direction of the arrow in the drawing according to supply and discharge of compressed air. The tool unit 4 includes a table 5 connected to the slide part 3a of the air slide mechanism 3, a clutch part 7 connected to the table 5, a driver 6 connected to the clutch part 7, The bit unit 8 is connected to the tip of the clutch portion 7.
[0008]
The driver 6 has a prismatic output shaft 6b that rotates under the drive of an AC servomotor 6a (hereinafter referred to as a motor 6a).
[0009]
The clutch portion 7 is provided with a clutch shaft 74 that can be rotated only in one direction with respect to the case member 7a by the action of the one-way clutch 73 via bearings 71 and 72 and a one-way clutch 73 housed in the case member 7a. Have In the clutch shaft 74, a transmission shaft 75 connected to the output shaft 6b is concentrically rotatable and a square hole 75a having a rectangular cross section is formed at the tip of the transmission shaft 75. It is. In addition, slits 74a and 74a are formed at opposing positions below the clutch shaft 74, and support bars 76 and 76 are disposed above the slits 74a. The support bars 76 and 76 can rotate only from the parallel state to the clutch shaft 74 side, and are urged by springs 77 and 77 so as to be always in the parallel state.
[0010]
The bit unit 8 has a structure in which a coil spring 81 for chucking the cap C is supported by an outer 82 and an inner 83. The outer 82 is suspended and supported by the clutch portion 7 by always engaging the upper hooks 82 a and 82 a with the support bars 76 and 76. The body 84 of the outer 82 has a hollow shape, and has a shape in which an outer peripheral facing portion is cut out, and stoppers 85 and 85 projecting into the body 84 are disposed in the cutout portions 84a and 84a. ing. The stoppers 85 and 85 are attached by sandwiching the body 84 between two parts 85a and 85b and fastening them with screws 85c. If the screws 85c are loosened, the stoppers 85 and 85 are placed at any position along the notch 84a. It is possible to move. A pressing plate 84b is integrally fixed to the lower portion of the body 84.
[0011]
The inner 83 is rotatably incorporated in the body 84 of the outer 82, the coil spring 81 is fitted in the lower part, and the prismatic part that can be fitted and fitted into the square hole 75 a of the transmission shaft 75 in the upper part. 83a is formed. Locking pieces 86 and 86 are fixed to the outer periphery of the inner 83 at an interval of 90 °. The locking pieces 86, 86 are configured such that the inner 83 abuts against the stopper 85 as the inner 83 rotates relative to the outer 82.
[0012]
The coil spring 81 is formed to have an inner diameter that allows the cap C to be pushed and fitted in a steady state, and is configured to hold the fitted cap C. The coil spring 81 has one end connected to the inner 83 and the other end connected to a pressing plate 84b below the outer 82. With this, when the inner 83 rotates forward or reverse with respect to the outer 82, the coil spring 81 accordingly. The diameter decreases or expands. The coil spring 81 is in direct contact with the cap C and transmits drive to the cap C. Therefore, in order to prevent damage to the cap C and increase the coefficient of friction, the surface is preferably coated with vinyl, a resin material, or the like.
[0013]
Next, the operation of the cap fastening machine 1 according to the present invention will be described. When the cap C is fastened to a workpiece such as a container, the robot operates to position the tool unit 4 in a state where the cap C is fitted and held on the coil spring 81 on the workpiece. Subsequently, the slide mechanism 3 is actuated to lower the tool unit 4, and the motor 6a starts driving to transmit rotational drive in a direction in which the cap C is fastened to the transmission shaft 75 (hereinafter, the motor 6a in this direction is connected). The drive is forward rotation, and the reverse drive of the motor 6a is called reverse rotation drive). Accordingly, drive transmission is performed from the transmission shaft 75 to the inner 83, and further, drive transmission is performed from the inner 83 to the outer 82 and the clutch shaft 74 through the coil spring 81. When the motor 6a is driven forward, the one-way clutch 73 is idling, and as a result, the transmission shaft 75 and the clutch shaft 74 rotate together. As a result, the entire bit unit 8 rotates in the cap tightening direction.
[0014]
When the cap C reaches the workpiece and is screwed in, the tightening torque increases accordingly. Due to the increase in the tightening torque, a difference occurs between the inner 83 and the outer 82 connected by the coil spring 81. That is, the rotation angle of the inner 83 receiving the drive transmission directly from the motor 6a is larger than the outer 82 to which a load due to the tightening torque is applied. As a result, the coil spring 81 is squeezed in the winding direction, and the holding force of the cap C fitted and held here is increased. In this way, since the holding force of the cap C is increased in proportion to the increase in the tightening torque of the cap C, slipping between the cap C and the coil spring 81 is prevented even when the tightening torque is increased. Cap C can be fastened to the workpiece with an appropriate torque.
[0015]
As described above, when the differential between the inner 83 and the outer 82 increases, the force applied to the cap C from the coil spring 81 increases accordingly. If this becomes too large, the cap C will be deformed / destructed. Therefore, when the coil spring 81 is appropriately squeezed, the locking piece 86 comes into contact with the stopper 85, and the differential between the inner 83 and the outer 82 is suppressed. The contact position between the locking piece 86 and the stopper 85 is set to an appropriate position by adjusting the position of the stopper 85 in advance based on the strength of the cap C, the final tightening torque value, and the like.
[0016]
When it is confirmed by detecting the load current value of the motor 6a that the cap C has been tightened to an appropriate final tightening torque, the motor 6a is then switched to reverse driving, and the cap C is loosened to the inner 83. Directional rotation is transmitted. This rotation is further transmitted to the outer 82 and the clutch shaft 74 via the coil spring 81. In this case, since the one-way clutch 73 is locked, the outer 82 and the clutch shaft 74 cannot rotate. Accordingly, the inner 83 rotates reversely with respect to the outer 82, whereby the coil spring 81 is released and loosened, and the holding force of the cap C is released. At this time, the locking piece 86 comes into contact with the stopper 85 when the coil spring 81 is released and loosened to the extent that the cap C is released. As a result, the inner 83 has the one-way clutch 73 as well. The lock effect extends. As a result, a state in which the coil spring 81 is moderately released and loosened is created and maintained.
[0017]
With the coil spring 81 unwound and loosened, the slide mechanism 3 moves backward to return the tool unit 4 to the up position. Thereafter, when the driving of the motor 6a is stopped, the coil spring 81 can return to its original state by its own elastic force, and can be prepared for the next operation. When the bit unit 8 needs to be replaced, the bit unit can be simply released by releasing the engagement between the hook 82a and the support bar 76 by rotating the support bars 76, 76 toward the clutch shaft 74. Can be removed.
[0018]
In the embodiment described above, the inner 83 constitutes the embodiment of the first member described in the claims, and the outer 82 is the implementation of the second member described in the claims. Forms. In addition, if the locking direction of the above-mentioned one-way clutch and the winding direction of the coil spring are reversed, the present invention can also be applied when the cap is loosened.
[0019]
【The invention's effect】
According to the cap tightening machine of the present invention, the coil spring is squeezed in proportion to the tightening torque, and thus the cap is held and tightened, so that proper cap tightening is achieved with a relatively simple structure. it can. In addition, it is possible to rationally realize the cap holding operation and the tightening operation by driving the coil spring and the motor, and unlike the conventional case, no dedicated resources such as air are required for holding the cap. It is easy to control and can contribute to resource saving. In addition, maintenance work can be reduced as compared with a conventional method using a chuck rubber. Furthermore, in the present invention, the holding power of the cap is increased in conjunction with an increase in the tightening torque of the cap, so that it is possible to easily cope with a cap tightening that requires a high final tightening torque. There is.
[Brief description of the drawings]
FIG. 1 is an enlarged partially cutaway cross-sectional view of a main part of a cap fastening machine according to the present invention.
FIG. 2 is a front view of a cap tightening machine according to the present invention.
3 is an enlarged cross-sectional view taken along line XX of FIG.
4 is an enlarged sectional view taken along line YY in FIG. 2;
FIG. 5 is an enlarged partial cutaway cross-sectional view of a main part showing a state where a bit unit of the cap tightening machine according to the present invention is removed.
FIG. 6 is a plan view of a bit unit in the cap fastening machine according to the present invention.
7 is a cross-sectional view taken along the line ZZ shown in FIGS. 4 and 6. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cap fastening machine 3 Air slide mechanism 4 Tool unit 6 Driver 6a AC servo motor 7 Clutch part 73 One-way clutch 74 Clutch shaft 75 Transmission shaft 76 Support bar 8 Bit unit 81 Coil spring 82 Outer 83 Inner 84 Body 85 Stopper 86 Locking Fragment

Claims (2)

A first member that can rotate by receiving rotation transmission, a second member that can rotate integrally with the first member and that can rotate relative to the first member, and these first members And a coil spring provided by connecting the second member ,
The coil spring is configured to fit and hold a cap that is tightened to an inner diameter portion thereof, one end of which is connected to the first member and the other end is connected to the second member, and the first member and the second member are connected to each other. A cap tightening machine configured to reduce or expand the diameter according to a differential angle when the member is rotating . 2. The cap according to claim 1, wherein the second member is supported via a one-way clutch so as to be rotatable in one direction with respect to the first member and not rotatable in the other direction. Fastening machine.

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