JPH0555373B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a submerged heat sealing device in an automatic packaging machine.

(Prior Art) As shown in FIG. 6, a heat sealing device that has been widely used in automatic packaging machines has protrusions 103 and 104 arranged at seal pitch intervals on the outer periphery of a pair of rotating bodies 101 and 102. are doing.
The protrusions 103 and 104 have arcuate surfaces corresponding to the seal length l, and are pressed against each other with a constant pressure by a spring 105 provided on the pivot of one rotating body 101. ing. The liquid to be packaged is already contained in the tube-shaped packaging film T that is fed in synchronization with the circumferential speed of the rotating bodies 101 and 102, and the film T is divided into sections at each interval between the protrusions 103 and 104. In recent years, so-called submerged heating, in which the material is heated and sealed, is being implemented.

(Problems to be Solved by the Invention) However, in the conventional heat sealing device described above, the heating temperature, pressing force, and sealing time are determined depending on the film material.
The circumferential speed of No. 2 was also limited, making it difficult to speed up the packaging operation.

Even under such restrictive conditions, the present invention employs an innovative heat-sealing mechanism that enables the production speed to be increased several times even if the rotational speed of the rotating body is increased several times. However, the heat-sealing time between the protruding parts is secured as before, and a nearly constant pressing force is applied to the sealing part of the packaging film under the control of a guide means using a cam etc. to squeeze and feed the liquid. To provide a heat sealing device having a relatively simple structure capable of surely performing submerged heat sealing by maintaining stable movement without shaking or meandering a packaging film.

(Means for Solving the Problems) The means for achieving the above object is to provide heat seal protrusions in parallel to each other at seal pitch intervals on the outer periphery of each of a pair of rotating bodies that are driven to rotate at an equal weekly speed. submerged heat in an automatic packaging machine that heat-seals the tube-shaped packaging film containing the liquid to be packaged, which is fed between the arc-shaped seal surfaces of the corresponding heat-seal protrusions, at each seal pitch interval. In the sealing device, the distance between the centers of rotation of each rotating body in a state where the arcuate sealing surfaces of the corresponding heat sealing protrusions do not contact each other is the distance from the center of rotation of the rotating body to the arcuate sealing surface of the heat sealing protrusion. While the arcuate sealing surface of the heat seal protrusion is in contact with each other, the abutting part is displaced from the rotation locus when it is not in contact with the tube so that the radius is shorter than the sum of the radii reaching the outermost circumferential point. An automatic packaging machine characterized in that each rotating body is guided by a guiding means using a cam or the like so that it follows the moving path of the shaped packaging film and returns to the above-mentioned orbital trajectory when the contact is completed. This is a submerged heat sealing device.

(Function) The distance between the rotation centers of each rotating body when the corresponding heat seal protrusions are not in contact with each other is greater than the sum of the respective radii from the rotation center of the rotor to the outermost point of the heat seal protrusions. While the heat-sealing protrusion is in contact, it is displaced from the orbital locus when it is not in contact, and the contact part is aligned along the movement path of the tubular packaging film, so that the contact is made short. Since each rotating body is guided by a guiding means so that it returns to the above-mentioned rotation locus when the rotation is completed,
The corresponding heat-sealing protrusions will start contacting each other at a point earlier than the line connecting the rotation centers of the respective rotating bodies. Since the heat-seal protrusions can be displaced so as to separate from each other or return together with the rotating body, the rotary body can continue to rotate while the heat-seal protrusions are in contact with each other. During this time, the rotation angle with respect to the contact length of the heat-seal protrusion, which generally corresponds to the heat-seal length, is increased, and a relatively long heat-seal time can be ensured. In other words,
The heat sealing speed can be increased accordingly. That is, as shown in Fig. 6, the rotation angle of the conventional heat seal protrusion relative to the contact length is 12.5°.
In the embodiment shown in FIG. 2, the angle is only 50°, which is approximately the same size according to the present invention, and is enlarged approximately four times. Therefore,
In the heat sealing device of the present invention, 4
Even if the heat sealing work speed is doubled, the same heat sealing time as before can be maintained.

In addition, since the above-mentioned displacement of the rotating body and the heat seal protrusion is guided by a guide means using a cam or the like, the pressing force inside the heat seal is maintained almost constant, and the contact portion second in between
As shown in the figure, the arcuate seal surface has a small curvature (for example, about 1/4) compared to the orbit of rotation, and the liquid is squeezed and fed powerfully, reliably, and evenly, and the tube-shaped packaging film can be shaken or meandered. This enables stable movement without causing any movement, and ensures submerged heat sealing.

(Example) Hereinafter, an example of the submerged heat sealing device for an automatic packaging machine according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the automatic packaging machine 1 according to the present invention continuously supplies a band-shaped packaging film 2 wound into a roll to a forming pipe 4 by a roller feeding device 3 and wraps it around the forming pipe. In the tube-shaped closed state, the overlapping portions of both side edges are sealed by a vertical heat sealing means 5 to form a tube-shaped packaging film T. Next, this automatic packaging machine 1 includes a heat sealing device 1 provided below the roller feeding device 3 on the machine stand F.
After sealing horizontally at every predetermined pitch using a tube and closing it into a tube shape, the liquid filler is supplied in advance from a filling chute (not shown) and kept in a liquid column state, and then the liquid filler is sequentially compartmentalized and packaged. Then, a cutter 6 separates each bag.

As shown in FIGS. 2 to 4b, the heat sealing device 10 of this embodiment is rotated equally in opposite directions indicated by arrows X and Y by motors 11M and 12M shown in FIG. 5, as described later. It is composed of a pair of rotating bodies 10a and 10b having the same shape and rotating at a high speed.
The rotating bodies 10a, 10b are rotated by a pair of substantially circular end plates 11a, 12a and the motors 11M, 12M, and are also rotated by bearings B ₁ , B ₁ shown in FIG.
Rotating wheels 11 and 12 are made up of hollow shafts 13 and 13a that are supported by a pair of end plates 11a and 12a and are fixedly connected to a pair of end plates 11a and 12a. Six heat seal protrusions 1 arranged at each central angle of 60°
4, 15. These heat seal protrusions 14 and 15 are made of a cylindrical body with a cavity into which an electric heater H is inserted, and an insertion hole h for a temperature detector such as a thermocouple is bored in the outer wall. . The conducting wires are inserted into the cavities of the hollow shafts 13, 13a.

One rotating body 10a has a structure in which a cylindrical body 14 is elastically supported, and has a pair of left and right end plates 11a, 11.
A guide opening 11b formed radially on the outer periphery of a.
, a pair of springs 1 that guide both ends of the cylindrical body 14 in a radially movable manner and are held in a sleeve 13b fixed to the hollow shaft 13.
6 and 16 urge and elastically support the cylindrical body 14 radially outward. Each cylinder 14
is a circle C ₁ whose outermost periphery of the arc-shaped seal surface is the same
It is regulated by the outer end of the guide opening 11b so as to be inscribed in the guide opening 11b.

The other rotating body 10b has a structure in which a cylindrical body 15 is fixedly supported, and a pair of left and right end plates 12a, 1
2a is fixed by bolts or the like so that the outermost peripheral part of the arcuate sealing surface is inscribed in the same circle _C2 having the same diameter as the circle _C1 of the one rotating body 10a.

For the pair of rotating bodies 10a and 10b having the above configuration, the distance L between their respective centers of rotation O ₁ and O ₂ is the center of rotation.
The basic position is set so that it is shorter than the sum of each radius R ₁ , R ₂ from O ₁ , O ₂ to the outermost point of the heat seal protrusions 14 , 15 , and the heat seal protrusions 14 during operation. , 15 are in contact with each other, while they are displaced from the orbits C ₁ and C ₂ when they are not in contact with each other,
The orbit corresponding to the above circle at the end of contact
It is provided on the machine base F so as to be displaced by cam means 17 and 18 as guide means so as to return to C ₁ and C ₂ . Heat seal protrusions 14, 15
The sealing action length l of the arcuate sealing surface can be determined by changing the shape of the abutting part as appropriate (for example, by changing the curvature of the arcuate sealing surface from 1/4 of the curvature of the orbit of rotation in this example). Can be changed and adjusted.

The cam means 17, 18 can take various forms, but for the sake of simplicity, the rotating bodies 10a, 1
The shaft ends of the hollow shaft 13 forming the rotation centers O ₁ and O ₂ of the rotating bodies 10a and 10b can be constructed from grooved cams that are slidably inserted into grooves having the shape shown in FIG.
It is configured to be rotated around rotation centers P ₁ and P ₂ at the same angular velocity as (for details,
(described later with figures). When the protrusions 14 and 15 are not in contact with each other, the shape of the cam groove is the same as the above-mentioned orbit.
C ₁ , C ₂ and after contact (second
The area between the rotation centers O ₁ and O ₂ expands away from the orbital loci C ₁ and C ₂ (indicated by A in the figure), and the projections 14 and 1
5 moves on the line connecting the rotation centers O ₁ and O ₂ to achieve the maximum displacement (indicated by B in Fig. 2. At this time, the rotation center moves to O ₁ ′ and O ₂ ′), and the distance between the rotation centers is shrinks, the contact ends (indicated by C in Fig. 2), and the rotational loci C ₁ and C ₂ are returned again.
It is designed to guide the rotating bodies 10a and 10b. While the arcuate sealing surfaces of the heat seal protrusions 14 and 15 are in contact, the elastic force of the springs 16 and 16 acts so that one protrusion 14 applies a constant pressing force to the other protrusion 15. It goes without saying that the shapes of the cam grooves of the cam means 17 and 18 are determined.

The rotating bodies 10a, 10b and the cam means 17, 1
The rotational drive mechanism of No. 8 will be explained with reference to Fig. 5.
In the simplest configuration, electric motors 11M and 12M with small reduction gears are controlled by a synchronous drive control circuit, etc.
The individual hollow shafts 13, 1 of the rotating bodies 10a, 10b
The hollow shafts 13, 13 are directly connected to the shaft ends of the shafts 3a and rotate at a constant speed in the opposite directions indicated by arrows X and Y in the same phase (matching the moving speed of the packaging film T).
Bearings B ₁ and B ₁ that rotatably support a are the center of movement.
The linear way W ₁ guides the motors 11M and 12M so that they can reciprocate on _the line connecting O 1 and O ₂ , and the motors 11M and 12M are also connected to the center O ₁ , via the linear way W ₂ via their supports B ₂ and B ₂ It is supported so that it can reciprocate on the line connecting O ₂ . Also, around each fixed position center P ₁ , P ₂ the motor M ₁ ,
At _M2 , the cam means 1 is moved in the arrow directions X and Y while maintaining the phase relationship shown in FIG. 2 at the angular velocity with the rotating bodies 10a and 10b.
7 and 18 are rotated synchronously by the above-mentioned control circuit, and the positions of the movement centers O ₁ and O ₂ of each hollow shaft 13 and 13a are controlled at the other shaft end by the cam grooves 17a and 18a. Ru. In yet another configuration (not shown), one motor is configured to rotate the rotating bodies 10a, 10b and the cam means 17, 18 at a constant angular velocity in the direction of the square arrow through an intermediate transmission gear train. However, in this case, the driven gears fixed to each hollow shaft 13 will roll around the driving gears, so the center movement between O ₁ ⇔ O ₁ ′ and O ₂ ⇔ _{O 2} ′ will be in an arc shape. (Due to the short distance, the shape is approximately linear), and the guide rail of the bearing of the hollow shaft 13 also has a shape along it. Various configurations other than these are possible.

To explain the operation of the heat sealing device 10 of this embodiment, as shown in FIG.
5, when the rotating bodies 10a, 10b are rotationally driven in the directions of arrows X and Y, they come into contact over a range of, for example, a central angle of 50°, and during this time, the rotating bodies 10a, 10b are rotated by the cam means 17, 18. It moves toward and away from the object and continues to rotate. Therefore, while the conventional heat-sealing protrusions 103 and 104 shown in FIG. 6 can only take the heat-sealing time at a central angle corresponding to the heat-sealing length l (the one shown is 12.5°), the present In the embodiment, since the amount of displacement of the protrusions 14 and 15 is large, the center angle until the heat seal length 1 completes contact can be set large (50° in the case shown), and the heat seal time can be increased. Become. Since the maximum heating temperature and heat-sealing time are determined depending on the material of the film, the heat-sealing operation speed of the heat-sealing device 10 can be increased by about 4 times in the case of the ones shown in FIGS. 2 and 6, for example. It is possible to raise it. This speed increase is provided with a preheating means in the vertical heat sealing means 5 so that vertical heat sealing can be performed sufficiently.

The degree of extension of heat sealing time is determined by rotating wheel 1.
Heat seal protrusion 1 provided on the outer periphery of 1 and 12
The selection is made by adjusting the numbers 4 and 15 and the amount of displacement of the protrusions 14 and 15.

(Effects of the Invention) As described above, according to the submerged heat sealing device in the automatic packaging machine of the present invention, the corresponding heat sealing protrusions are mutually connected at an earlier point in time than a line connecting the rotation centers of each rotating body. Since the protrusion itself or the rotating body can be moved away from each other and returned to normal position, the rotation angle corresponding to the contact length of the protrusion corresponding to the heat-sealing length can be adjusted. The heat sealing time can be relatively increased by the increased rotation angle. In other words, the heat sealing time is almost constant depending on the film material as well as the maximum heating temperature, so the heat sealing work speed can be increased.
It can greatly contribute to improving productivity. Furthermore, as mentioned above, the displacement of the rotating body and the heat-sealing protrusion is guided by a guiding means using a cam, etc., so the pressing force during heat-sealing is maintained almost constant, and the displacement between the abutting parts is To ensure that the liquid is squeezed and fed evenly and to move stably without shaking or meandering the tubular packaging film, thereby reliably performing submerged heat sealing.

[Brief explanation of the drawing]

FIG. 1 is a front view of an automatic packaging machine according to the present invention, FIG. 2 is a diagram illustrating the principle of the heat sealing device of the present invention,
Fig. 3a is a front view of one rotating body of the heat sealing device, Fig. 3b is a sectional view taken along the - line in Fig. 3a, Fig. 4a is a front view of the other rotating body, Fig. 4b is a cross-sectional view taken along the line 4a in FIG.
FIG. 6 is an explanatory diagram of a conventional heat sealing device. Explanation of symbols, 1... Automatic packaging machine, 10... Heat sealing devices 10a, 10b... Rotating body, 14,
15... Heat seal protrusion, L... Distance between centers of rotation, O ₁ , O ₂ ... Center of rotation, R ₁ , R ₂ ... Radius from the center of rotation to the outermost point of the heat seal protrusion, T...Tube-shaped packaging film, C ₁ , C ₂
...Epicycle locus.

Claims (1)

[Claims] 1 Heat seal protrusions are arranged parallel to each other at each seal pitch interval on the outer periphery of each of a pair of rotating bodies that are driven to rotate at a constant speed, and the heat seal protrusions are fed between the arcuate seal surfaces of the corresponding heat seal protrusions. In a submerged heat-sealing device in an automatic packaging machine that heat-seals a tube-shaped packaging film containing a liquid to be packaged at each seal pitch interval, the arc-shaped sealing surfaces of the corresponding heat-sealing protrusions are mutually connected to each other. The distance between the centers of rotation of each rotating body when they are not in contact with each other is shorter than the sum of the radii from the center of rotation of the rotating body to the outermost point on the arcuate sealing surface of the heat seal protrusion, and While the arc-shaped sealing surface of the seal protruding part is in contact, the contact part is displaced from the rotation locus when it is not in contact, and the contact part is moved along the moving path of the tube-shaped packaging film, and when the contact is finished, the above-mentioned circumference is displaced. 1. A submerged heat sealing device for an automatic packaging machine, characterized in that each rotating body is guided by a guide means using a cam or the like so as to return to a rolling path.