JPH07100495B2 - Sealing device for packaging machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Use) The present invention relates to a sealing device that presses a packaging film with a pair of seal bars at fixed time intervals for welding or fusing, and in particular, a pair of seal bars is used. The present invention relates to a long-seal type sealing device which moves linearly for a certain period of time when a wrapping film is squeezed and keeps squeezing the wrapping film.

(Prior Art) When heat-sealing a packaging film which is relatively difficult to be welded, it is necessary to continue to press the packaging film for a certain period of time with a pair of seal bars in order to lengthen the heating time. The publication discloses a sealing device suitable for heating a film for a long time. As shown in FIG. 6, the device disclosed in this publication uses a seal bar (5) at the tips of the propellers (3) and (4) rotated by the drive shafts (1) and (2).
The seal bars (5) and (6) are engaged with the pins (7) and (8) at both ends of (6) to rotate along the grooved cams (9) and (10) of the semi-circular shape. (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. However, this type of spring is inevitably large in size 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 Problems) In order to achieve the above object, the present invention provides crankpins on eccentric parts of driving gears at both ends of a driving shaft whose axis is horizontally supported by a machine base. Each of the crank rods is pivotally supported, and an upper seal bar is provided on the lower surface of an upper support bar installed between the upper ends of the crank rods via tension springs. A cantilever shaft formed on one surface of the driven gear is rotatably supported in holes formed on vertical surfaces on both sides of the machine base, and these two driven gears are engaged with both driving gears on the upper side between the driving gears. At the same time, when the crank pin of the driving gear is at the bottom dead center, the pins at both ends of the lower support bar are rotatably supported in the bearing holes formed at the top dead center of the driven gears. The extension portions of these pins are slidably engaged with slits formed along the longitudinal direction of both crank rods in a non-rotatable state, and the lower seal bar is attached to the upper surface of the lower support bar via a tension spring. The driving shaft is provided so as to face the upper seal bar, and the driving shaft is connected to the 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 the two driving gears move up and down in a certain cycle by the revolution of the crank pins. The upper support bar and the upper seal bar supported at the upper end are 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 holes of the machine base, and the lower support bar and the lower seal supported in the bearing holes formed in the eccentric portion of the driven gears. Rotate the bar. 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 lower support bar reaches the bottom, the upper support bar reaches the top. Reach Moreover, since both ends of the lower support bar are engaged with the slits formed along the crank rod, the crank rod is supported by the crank pin and the lower support bar at two points, so that the vertical state is always maintained and the upper part is maintained. Always hold the support bar directly above the lower support bar. When the upper and lower support bars approach each other, the upper and lower seal bars between the two support bars abut each other, and the upper and lower support bars are held in pressure contact with each other by the compression of the tension spring.

(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 a erected state, 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 the driving gears (13) (13), and the crank rods (16) (16) The upper support bar (17) is fixed to the erected state between the upper ends with screws (18) (18). Therefore, the rotation of the driving gears (13) (13) causes the upper support bar (17) to rotate.
Moves up and down together with the crank rods (16) (16). Also, bolts (21) are slidably inserted into three holes (19), (19) and (19) penetrating vertically through the upper support bar (17), and the upper seal bar is attached to the lower ends of these three bolts. (20) is fixed, and tension springs (22) (22) ... Are provided in a large number of rows between the upper support bar (17) and the upper seal bar (20).

On the other hand, a relatively large-diameter hole (25) is formed in the upper part of the machine base (11) (11), and the hole (25) projects to one side of the driven gear (27) via a ball bearing (26). The cantilever shaft (28) thus formed is supported, and the two driven gears (27) (27) are rotatably supported on 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 support bar (30) are rotatably supported in the bearing hole through the ball bearing (31), and thus, between the driven gears (27) and (27). A lower support bar (30) is supported by the. Moreover, the pins (32) (32) at both ends of the lower support bar (30) are further extended outward and engaged with the slits (33) formed along the crank rods (16) (16). Further, bolts (35), (35) and (35) are slidably inserted into the three holes (34) (34) (34) vertically penetrating the lower support bar (30), respectively. The lower seal bar (36) is fixed and tension springs (37) (37) are provided between the lower support bar (30) and the lower seal bar (36) in multiple rows.
(37) ... is installed.

When the crank pin (15) of the driving gear (13) is at the top dead center as shown in FIG. 3, the bearing holes (29) of the driven gear (27) reach the bottom dead center symmetrically. The upper seal bar (20) supported by the crank rod (16) and the lower seal bar (36) supported by the bearing hole are in the farthest state, but as shown in FIG. 4, a pair of upper and lower gears mesh with each other. When the rotation angles of (13) and (27) change synchronously, the crank rod (16), which is supported by the crank pin (15) and the pin (32) at two points, always moves in the vertical state, and the upper and lower seals are sealed. The bars (20) (36) are made to approach each other while always facing each other vertically, and finally these seal bars (20) (36) are brought into pressure contact with each other. When both seal bars (20) (36) abut each other, both seal bars tension each other and compress the springs (22) (37) to escape vertically, so that the upper and lower seal bars (20) (3)
6) moves in the orbit as shown by the arrow in Fig. 5 and applies heat to the film only while both seal bars are in contact with each other.

(Effect) While the upper seal bar is provided on the upper end of the crank rod supported by the crank pin of the driving gear via the upper support bar,
A lower seal bar is provided through a lower support bar in a bearing hole formed in an eccentric part of a driven gear that meshes with the driving gear.
Both the upper and lower seal bars are made to approach each other by the movement of the driving gear and the driven gear.There is a sufficient installation space for the tension springs behind the upper and lower seal bars, and a tension spring with a large spring load can be installed. As a result, the film can be pinched with a strong force, and 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) …… upper support bar, ( 20) …… Upper seal bar, (22) …… Tension spring, (25) …… Hole, (27)…
… Driven gear, (28) …… Cantilever shaft, (29) …… Bearing hole,
(30) …… Lower support bar, (36) …… Lower seal bar,
(37) …… tension spring.

Claims (1)

[Claims] 1. A crank pin is provided on each eccentric portion of a driving gear at both ends of a driving shaft whose axis is horizontally supported by a machine base, and the ends of the crank rods are pivotally supported by these crank pins, respectively. While an upper seal bar is provided on the lower surface of the upper support bar installed between the upper ends via a tension spring, a cantilever shaft formed on one side of two driven gears having the same number of teeth as the driving gear is provided on both sides of the machine base. When the two driven gears are rotatably supported in a hole formed in a vertical surface, and are engaged with both the driving gears on the upper side between the driving gears, and the crank pin of the driving gear is at the bottom dead center. , The pins at both ends of the lower support bar are rotatably supported in the bearing holes formed at the top dead center of both driven gears, and the extension parts of these pins are arranged in the longitudinal direction of both crank rods. And a lower seal bar is provided on the upper surface of the lower support bar so as to face the upper seal bar via a tension spring, while the slit is formed in a non-rotatable manner. Sealing device for a packaging machine, which is connected to the rotary power unit.