JPH06102453B2 - Sealing device for packaging machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sealing device that presses a packaging film with a pair of sealing bars at fixed time intervals to weld or melt it, and in particular, a pair of sealing bars is packaged. The present invention relates to a long-seal type sealing device in which, when a film is pressed, it moves linearly for a certain period of time and continues to press the packaging film. (Note that the present invention is an improvement of Japanese Patent Application No. 62-92833.) (Prior Art) When heat-sealing a packaging film which is relatively difficult to be welded in the past, a pair of seal bars is used to secure a long heating time. Must be pressed for a certain period of time to continue, and Japanese Patent Publication No. 022552/43 discloses a sealing device suitable for heating the film for a long time. In the device shown in the publication, a tip of a propeller (3) (4) rotated by a drive shaft (12) is attached to a seal bar (5) as shown in FIG.
The seal bars (5) and (6) are engaged with the pins (7) and (8) at both ends of the groove (6) to rotate the seal bars (5) and (6) along the grooved cams (9) and (10). (9) The seal bars (5) and (6) continue to pinch the wrapping film in the straight track portions of the opposing portions in (10).

(Problems to be solved by the invention) However, a slight gap is provided between the groove cams (9) (10) and the pins (7) and (8) so that the pins can move smoothly. Therefore, due to this gap, the two seal bars (5) and (6) have a structure in which the packaging film cannot be strongly pinched. A spring is provided inside the seal bar (5) (6) and the spring force is used to increase the clamping force against the packaging film, but this type of spring is inevitably large due to the installation space. Since it could not be used, it had the drawback of lacking strength.

The present invention has been made in view of the above points, and an object of the present invention is to provide a long seal device capable of strongly pinching a packaging film.

(Means for Solving the Problem) In order to achieve the above object, the present invention provides a crank pin at an eccentric portion of a driving gear fixed to both ends of a driving shaft supported such that the axis is horizontal. , The lower ends of the crank rods are pivotally supported by these crank pins, and the guide rods are projected above the upper stopper surfaces of the upper ends of the crank rods, and both ends of the upper seal bar can be slid along the guide rods. And the upper seal bar is pressed against the stopper surface by a spring provided between the heads at the upper ends of both guide rods and the upper seal bar, while having the same number of teeth as that of the driving gear.
A cantilever shaft formed on one surface of each driven gear is rotatably supported in a hole formed on a vertical surface on both sides of the machine base, and these two driven gears are engaged with these driving gears above the driving gear. In addition, when the crank pin in the driving gear is at the bottom dead center, the pins at both ends of the lower seal bar are rotatably supported in the bearing holes formed at the top dead center in the driven gears, The pins are slidably engaged with slits formed along the longitudinal direction of both crank rods in a non-rotatable manner, and the driving shaft is connected to a rotary power unit.

(Operation) When the two driving gears are rotated by the driving shafts supported by the machine base, the crank rods pivotally supported by the crank pins of these driving gears move in the vertical direction in a constant cycle due to the revolution of the crank pins. The upper seal bar supported on the upper end is moved up and down.

On the other hand, simultaneously with the rotation of both the driving gears, the driven gears that mesh with these driving gears also start to rotate in the hole of the machine base, and rotate the lower seal bar supported in the bearing hole formed in the eccentric part of the driven gear. . When the crank pin of the driving gear is at the bottom dead center, the bearing hole of the driven gear is formed at the top dead center, so when the bottom seal bar reaches the bottom, the top seal bar reaches the top. Reach Moreover, since both ends of the lower seal bar are engaged with the slits formed along the crank rod, the crank rod is supported by the crank pin and the lower seal bar at two points,
Always kept vertical and always keep the upper seal bar directly above the lower seal bar. Then, while the upper and lower seal bars are in contact with each other, the upper and lower seal bars are held in pressure contact with each other for a certain period of time by compression of the spring at the upper part of the upper seal bar.

(Example) As shown in FIGS. 1 and 2, a pair of plate-shaped machine bases (1
1) The driving gears (13) and (13) are fixed to both ends of the driving shaft (12) supported in an erected manner between (11), and the driving shaft (12) is fixed by the input from the chain wheel (14) fixed to the driving shaft. ) To rotate continuously. Further, the lower ends of the crank rods (16) (16) are pivotally supported by the crank pins (15) (15) formed in the eccentric portions of both the driving gears (13) (13), and the crank rods (16) (16) are also supported. Thinner guide rods (18) (18) are extended from the stopper surfaces (17) (17) at the upper end of the upper end of the upper seal bar (20) and the holes (19 ) (19) is slidably supported, and the upper seal bar (20) is stopped at the upper end of the crank rod by the tension of springs (22) and (22) provided under the heads (21) and (21) at the upper end of the guide rod. Surface (17) (1
It is fixed so that it is pressed against 7). Therefore, the driving gear (1
3) The upper seal bar (20) moves up and down by the rotation of (13).

On the other hand, a relatively large-diameter hole (25) is formed in the upper part of the machine base (11) (11), and protrudes to one side of the driven gear (27) via the ball bearing (26) in the hole (25). By supporting the cantilever shaft (28) formed as described above, the two driven gears (27, 27) are rotatably supported by the machine base. The driven gear (27) has the same number of teeth as the driving gear (13), and the driven gear meshes with the driving gear. When the crank pin (15) of the driving gear (13) is at the bottom dead center, the bearing hole (29) is formed at the top dead center of the driven gear (27).
And the pins (32) at both ends of the lower seal bar (30) are rotatably supported in the bearing hole via ball bearings (31), and thus, between the driven gears (27) and (27). The lower seal bar (30) is supported by the. Moreover, the pins (32) (32) at both ends of the lower seal bar (30) are further extended outward and engaged with the slits (33) formed along the crank rods (16) (16).

When the crank pin (15) of the driving gear (13) is at the top dead center as shown in FIG. 3, the bearing hole (29) of the driven gear (27) reaches the bottom dead center symmetrically. The upper seal bar (20) supported by the crank rod (16) and the lower seal bar (30) supported by the bearing hole are in the farthest state, but as shown in FIG. When the pair of gears (13) and (27) synchronously change the rotation angle, the crank rod (16) supported at two points by the crank pin (15) and the pin (32) always moves while maintaining the vertical state. Then, the upper and lower seal bars (20) (30) are made to approach each other while always facing each other, and finally these seal bars (20) (30) are brought into pressure contact with each other. When the lower seal bar (30) is pushed up from below, the upper seal bar (20) compresses the spring (22) and escapes upward, so that the upper and lower seal bars (20) (3).
0) moves in the orbit as shown by the arrow in FIG. 5, and heat is applied to the film only while both seal bars are in contact with each other.

(Effect) While an upper seal bar is provided on the upper end of the crank rod supported by the crank pin of the driving gear, a lower sealing bar is provided in the bearing hole formed in the eccentric part of the driven gear that meshes with the driving gear, and the driving gear and the driven gear are provided. The upper and lower seal bars are made to approach each other by interlocking with, and there is a sufficient installation space for the spring at the upper part of the upper seal bar, and a spring with a large spring load can be installed.
There is an effect that the film can be pinched with a strong force and that the upper and lower seal bars can be held so as to be always facing each other by a simple gear structure with two upper and lower gears.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view in which the position of a seal bar is different from the previous figure, and FIG.
FIG. 4 is a side view of the main part of FIG. 1, FIG. 4 is a side view of the intermediate point between FIG. 1 and FIG. 2, FIG. 5 is an explanatory view of the rotation orbits of a pair of seal bars, and FIG. It is explanatory drawing of a prior art example. (11) …… machine stand, (12) …… driving shaft, (13) …… driving gear, (15) …… crank pin, (16) …… crank rod, (17) …… stopper surface, (18 ) …… Guide rod,
(20) …… Upper seal bar, (21) …… Head, (22)
...... Spring, (25) …… Hall, (27) …… Driven gear, (28) …… Cantilever shaft, (29) …… Bearing hole, (30)…
… Lower seal bar, (33) …… Slit.

Claims (1)

[Claims] 1. A crank pin is provided at an eccentric portion of a driving gear fixed to both ends of a driving shaft supported so that its axis is horizontal, and a lower end of a crank rod is pivotally supported by each of these crank pins, and both of the above are provided. The guide rods are projected above the upper stopper surface of the upper end of the crank rod, and both ends of the upper seal bars are slidably installed along these guide rods. An upper seal bar is pressed against the stopper surface by a spring provided between the two, and cantilever shafts formed on one surface of two driven gears having the same number of teeth as the driving gear are formed on vertical surfaces on both sides of the machine base. The hole is rotatably supported, and these two driven gears are engaged with these driving gears on the upper side of the driving gear, and a clan in the driving gear is provided. When the pin is at the bottom dead center, the pins at both ends of the lower seal bar are rotatably supported in the bearing holes formed at the top dead center of the driven gears, respectively, and these pins of the both crank rods are supported. A sealing device for a packaging machine, wherein the driving shaft is connected to a rotational power unit while slidably engaged with a slit formed along the longitudinal direction in a non-rotatable state.