JPH0451137Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a bag sealing device, for example, a device used in a vacuum packaging machine or the like to seal the opening of a bag by welding it with a hot wire.

(Prior Art) This type of bag sealing device includes a hot wire receiving part disposed in an elongated manner, and a hot wire fixing part provided in an elongated manner facing the hot wire receiving part and moved toward and away from the hot wire receiving part.
A structure is adopted in which an elongated strip-shaped hot wire is arranged along the surface of the hot wire fixing part that comes into contact with and away from the hot wire receiving part, and both ends of the hot wire are fixed to both ends of the hot wire fixing part.

This bag sealing device places the opening of the bag to be sealed between the heat ray receiving part and the heat ray fixing part, and then moves the heat ray fixing part in the direction of the heat ray receiving part to direct the heat rays to the opening of the bag. By pressing the hot wire and energizing the hot wire, the surface temperature of the energized hot wire rises, and the opening of the bag is welded and sealed.

In conventional bag sealing devices, when the hot wire is energized during bag welding and its surface temperature rises, its entire length increases due to thermal expansion.However, since both ends of the hot wire are fixed to the hot wire fixing part, the thermally expanded hot wire is It becomes slack in the direction of its entire length and deforms into a wave shape. Therefore, there were problems in that wrinkles were formed in the welded portion of the bag and that poor welding was likely to occur.

Therefore, as described in Japanese Patent Publication No. 35-13543, Japanese Utility Model Publication No. 42-5359, or Japanese Utility Model Publication No. 57-43125, a structure in which springs are directly stretched on both ends of a hot wire is known. ing.

(Problems to be solved by the invention) In the above-mentioned conventional structure in which both ends of the hot wire are directly connected with springs, even if the thermally expanded hot wire is prevented from loosening, the fixation of the hot wire becomes unstable and the bag is welded. It has the problem of easily causing defects.

The present invention was developed in view of the above-mentioned problems. It prevents the hot wire from deforming due to thermal expansion, prevents wrinkles and poor welding of the welded part of the bag, and securely fixes the hot wire. The present invention provides a bag sealing device with stable welding.

(Means for Solving the Problems) The bag sealing device of the present invention includes a hot wire receiver provided in an elongated manner, and a hot wire fixing device provided in an elongated manner opposite to the hot wire receiver and operated toward and away from the hot wire receiver. and a hot wire disposed along a surface of the hot wire fixing part that comes into contact with and away from the hot wire receiving part, and having both ends fixed to both end surfaces of the hot wire fixing part, and at least one of the hot wire fixing part. A compression spring and a pin protruded outward by the compression spring are stored in a storage hole formed in the end surface, and the pin is brought into contact with the hot wire,
A pin biased by this compression spring applies tension to the hot wire in its length direction.

(Function) In the bag sealing device of the present invention, tension is applied to the hot wire 25 by the tension mechanism 29 using a pin biased by a compression spring, and thermal expansion of the hot wire 25 is absorbed.
This prevents the hot wire 25 from deforming. Since both ends of the hot wire are fixed to the hot wire fixing parts, the hot wire is stably held and the bag can be reliably welded.

(Embodiment) Hereinafter, the configuration of an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a vacuum packaging machine, in which a vacuum container 2 for vacuum packaging an object to be packaged P is arranged at the top, and a vacuum pump (not shown) etc. is located.

This vacuum container 2 includes a lower container 3 having a peripheral wall 3a at the peripheral edge and an open top surface, and a lower container 3 which is provided on the upper surface of the lower container 3 so as to be openable and closable, and the peripheral edge is crimped to the upper end of the peripheral wall 3a in an airtight state. The inside of the vacuum container 2 is composed of a lid 4, and the lid 4 closes the upper surface of the lower container 3. The inside of the vacuum container 2 is suctioned to a substantially vacuum state by a vacuum pump.

The lid 4 is made of, for example, a transparent material, and has a raised portion 4a in the center.

Reference numeral 5 denotes a bag sealing device provided along one edge of the vacuum container 2. This bag sealing device 5 includes a heat ray receiver 6 provided on the inner surface of the lid body 4, and a bag sealing device 5 provided in the lower container 3 that can be raised and lowered. A hot wire fixing part 8 supported by a mechanism 7 is provided.

The heat ray receiving portion 6 is made of a rubber material and is provided in an elongated manner, and includes a holding frame 9 and a spacer 10 having a substantially U-shaped cross section.
It is fixed along one edge of the inner surface of the lid body 4 via. Further, a base 12 of a bag presser member 11 is fixed between the holding frame 9 and the spacer 10, and a bag presser piece 13 is inclined downwardly inside the vacuum container 2 from the base 12 of the bag presser member 11. The tip of the bag presser piece 13 is located below the lower surface of the heat ray receiver 6.

Furthermore, a bag presser frame 14 is screwed and fixed to the side surface of the holding frame 9 facing the peripheral wall 3a of the lower container 3, and the lower end of the bag presser frame 14 is suspended via a horizontal portion to a heat wire fixing portion 8. It is located on one side of

The elevating mechanism 7 has a cylindrical container body 16 that is airtightly fixed to the lower surface of the lower container 3 via an annular O-ring 15, and a bottom plate 3b of the lower container 3 is disposed in the center of the container body 16. Cylinder shaft 1 that penetrates the top surface of
7 is arranged vertically movably, and this cylinder shaft 17
A piston 18 is fixed to the lower end of the container body 16, and an O-ring 19 fitted around the outer circumference of the piston 18
The piston 18
A cylinder chamber 20 is located between the top surface of the container body 16 and the inside of the vessel body 16.
is formed.

The piston 18 is urged downward by a spring 21 disposed within a cylinder chamber 20, and is in contact with a stopper 22 so that its downward movement is restricted.

Further, a cylinder chamber 2 is provided on the side of the vessel body 16.
A cylinder suction port 23 is provided in communication with the cylinder suction port 23, and a vacuum pump is connected to the cylinder suction port 23 via a valve mechanism (not shown). Note that, as shown in FIG. 2, the elevating mechanism 7 is provided at two locations along the length direction of the hot wire fixing section 8.

As shown in FIG. 3, the hot wire fixing part 8 is
Each cylinder shaft 17 is made of a non-conductive material and is formed into a flat plate shape and elongated, and protrudes from the bottom plate 3b of the lower container 3.
It is placed on the upper end of the container 17 and arranged along one edge of the lower container 3. A fitting hole 2 into which the cylinder shafts 17, 17 are inserted is provided on the lower surface of the hot wire fixing part 8.
4a and 24b are provided, and one of the fitting holes 24
b is provided in the shape of a long hole with a wide hole width in the length direction of the hot wire fixing part 8, which makes it difficult to move the cylinder shafts 17, 17 of both the lifting mechanisms 7, 7 up and down at the same time. and each cylinder shaft 17,
If the operation time of 17 is different, the hot wire fixing part 8
If the inclination is large during operation, the hot wire fixing part 8 will be locked in that inclination state, so the inclination of the hot wire fixing part 8 is absorbed by the fitting hole 24b.

Further, an elongated strip-shaped heating wire 25 is arranged along the upper surface of the heating wire fixing section 8 to face the heating wire receiving section 6, and both ends of the heating wire 25 are inserted through fixing holes 26 provided at each end thereof. , is fixed approximately at the center of the end surface of the hot wire fixing part 8 by a fixing screw 28 via a presser metal fitting 27.

Moreover, tension is applied to the hot wire 25 in the length direction of the hot wire 25 by a tension mechanism 29.
This tension mechanism 29 consists of a compression spring 30 and a push pin 31 arranged in a housing hole 8b of a protrusion 8a provided at the top of both end faces of the hot wire fixing part 8, and the push pin 31 is attached to the end of the hot wire 25. It contacts the back surface and is pressed outward in the length direction of the hot wire 25 by the elasticity of the compression spring 30.

Further, a conductive plate 32 is fixed to the lower part of the protrusion 8a on the end surface of the hot wire fixing part 8 by the fixing screw 28 and the connecting screw 33, and this conductive plate 3
The end of the hot wire 25 is connected and fixed to the upper part of the lead wire 3, and the lead wire 3 is connected to the lower part by a connecting screw 33.
4 are connected and fixed, and current is applied from this lead wire 34 to the hot wire 25 through the conductive plate 32.

A nozzle 36 having a gas outlet 35 opening at the upper end is arranged between the heat wire fixing part 8 and the presser frame 14 on the side thereof. It is connected to the gas cylinder via a valve mechanism (not shown).

Furthermore, on the bottom plate 3b of the lower container 3, a mounting table 37 is arranged on which the object to be packaged P is placed when the object to be packaged P is small.

Next, the operation of this embodiment will be explained.

When vacuum packaging the packaged item P, the packaged item P is stored in a synthetic resin bag 38 with one end closed, placed on the mounting table 37 of the lower container 3 with the lid 4 open, and the bag is placed. The opening 39 of 38 is placed on the hot wire fixing part 8, and the lid 4 is placed on the upper surface of the lower container 3.

Then, the air inside the vacuum container 2 and the bag 38 is sucked into a vacuum by the vacuum pump, and then,
By suctioning the air in the cylinder chamber 20 of the lifting mechanism 7 through the cylinder suction port 23, the piston 18
is pulled up against the spring 21, the cylinder shaft 17 and the hot wire fixing part 8 rise, the hot wire 25 of the hot wire fixing part 8 is pressed against the hot wire receiving part 6 through the opening 39 of the bag 38, and, By energizing the hot wire 25, the surface temperature of the hot wire 25 increases, the opening 39 of the bag 38 is thermally welded, and the packaged object P inside the bag 38 is sealed in a vacuum state.

At this time, when the surface temperature of the hot wire 25 increases due to energization, the total length increases due to thermal expansion, but the hot wire 25
The push pins 31, 31 of the tension mechanisms 29, 29 are shown in FIG.
Since tension is applied to the bag 38, the bag 38 is not deformed in a wavy manner in the length direction, and the welded portion of the bag 38 can be prevented from wrinkling or welding failure. Moreover, since both ends of the hot wire 25 are fixed, it is stably held.

Moreover, after welding is completed, inside the cylinder chamber 20,
By switching the valve mechanism, atmospheric air is sent from the cylinder suction port 23, and the piston 18 is pushed down by the elasticity of the spring 21 and returns to its pre-operation state.
The cylinder shaft 17 and the hot wire fixing part 8 are lowered,
The hot wire 25 separates from the hot wire receiving portion 6.

Note that the vertical movement time of the piston 18 can be arbitrarily adjusted and controlled by a valve mechanism provided in the middle of the piping between the cylinder suction port 23 and the vacuum pump.

Next, when packaging the object P with gas, as described above, after the air in the vacuum container 2 and the bag 38 is vacuumed, gas is ejected from the nozzle 36 into the bag 38. , gas is sealed inside the bag 38, and the opening 39 of the bag 38 is welded with the hot wire 25, thereby sealing the packaged object P inside the bag 38 together with the gas.

At this time, the bag 38 expands inside the vacuum container 2 due to the gas jet force, but the bag holding member 11 suppresses the expansion of the opening 39 of the bag 38.
The vertical displacement of the welded portion of the opening 39 can be reduced, and wrinkles and poor welding can be prevented from occurring. Also,
Bag 3 when gas is ejected by bag holding frame 14
This can prevent the opening 39 of No. 8 from floating up.

In the above embodiment, the tension mechanisms 29, 29 are provided at both ends of the hot wire 25, but the tension mechanism 29 may be provided only at one end of the hot wire 25.

(Effects of the invention) According to the invention, by applying tension to the hot wire using a pin biased by a compression spring of the tension mechanism, thermal expansion of the hot wire is absorbed and deformation of the hot wire is prevented. Therefore, when welding the bag, the hot wire does not become wavy in the length direction, which prevents wrinkles and poor welding at the welded part of the bag.
Moreover, since both ends of the hot wire are fixed, it is stably held and the bag can be reliably welded.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the bag sealing device of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a perspective view thereof. 6... Heat wire receiving part, 8... Heat wire fixing part, 8b...
Storage hole, 25... Heat wire, 30... Compression spring, 31
……pin.

Claims (1)

[Claims for Utility Model Registration] An elongated hot wire receiving part, a long and thin hot wire fixing part facing the hot wire receiving part and moving toward and away from the hot wire receiving part, and the hot wire of the hot wire fixing part. a hot wire disposed along a surface that approaches and separates from the receiving part and having both ends fixed to both end faces of the hot wire fixing part, and a compression spring and a compression spring in a storage hole formed in at least one end face of the hot wire fixing part. A pin protruded outward by the compression spring is housed, and the pin is brought into contact with the hot wire, and the pin biased by the compression spring applies tension to the hot wire in the length direction. bag sealing device.