JPS5914322Y2 - Packaging machine film holding device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a film pressing device for a packaging machine.

Conventionally, there are various packaging machines that automatically wrap products with stretch film, but all of them require a film holding mechanism that clamps and fixes the edges of the film during the wrapping process and releases it.

However, in the conventional apparatus, the film holding mechanism is driven by air pressure, which requires a large installation area and has problems such as noisy driving noise.

Furthermore, it is desirable that a certain amount of resistance be generated by the film holding mechanism when folding the film, but since the air-driven type opens the film instantaneously, there is a problem that the stretched state of the film becomes weak after wrapping. be.

This idea was developed in consideration of these points, and the drive noise is quiet, the device can be made smaller, and the film presser and release operations are performed gently to achieve a highly tensioned film tension state. The purpose of the present invention is to provide a film pressing device for a packaging machine that can.

In this invention, a fixing plate is formed integrally or separately with a frame, and a presser body is provided on the frame, which is made up of an elastic plate facing the fixing plate and a rigid plate integrally formed with the elastic plate at a distance. The fixing plate and the elastic plate form a presser part that clamps the film, and a driving body that engages with the rigid plate of the presser body and drives the presser body is driven by a motor or a solenoid. It is characterized in that it is connected to an electric drive unit.

Therefore, the presser body is driven by an electric drive unit via the drive body, so the device does not become bulky and the operating noise is quiet.The presser body is made up of an elastic plate and a rigid plate. Since the part consists of a fixed plate and an elastic plate, the operation when releasing the film is gradual and the clamping force is weakened, and this ensures that the tension of the film is maintained after packaging. This is what I did.

An embodiment of this invention will be described based on the drawings.

First, the overall structure will be explained with reference to FIG. A protruding part 2 is formed on the front surface of the main body case 1, and a carry-in part 4 is provided from the protruding part 2 to the middle part of the main body case 1, into which a product 3 to be packaged is fed.

A lift 5 is provided at the tip of the carry-in section 4 and is connected to a drive section (not shown) to move up and down.

A plate-shaped stopper 6 is provided at the rear of the lift 5 in a fixed position, and a slide plate that reciprocates in the horizontal direction between the lower edge of the stopper 6 and the upper surface of the lift 5 at the lowest position. 7 is provided.

Next, a roll body holder 10 is provided at the rear of the main body case 1 to rotatably hold two roll bodies 9 each having a film 8 wound thereon in a vertical position. The pulled out film 8 is guided by a plurality of guide rollers 11 and drawn into the main body case 1, and the leading end of the film 8 is attached to the film holding section 12.
is maintained by.

One of these two films 8 is selectively used.

Further, a support shaft 13 is provided below the film holding section 12, and a film presser 15 that presses the pulled out film 8 between it and a receiving plate 14 provided above is connected to the support shaft 13. A cutter 16 is rotatably provided on the shaft 13 and cuts the film 8 fixed between the film presser 15 and the film holding section 12. .

Next, a film feeder 17 is provided in substantially the same horizontal plane as the film holder 12 and is movable in a reciprocating manner, gripping the tip of the film 8 and drawing it out toward the front. Left and right presser bodies 18 are provided for gripping.

A front folding body 19 and a left and right folding body 20 are provided on top of each other, and the front folding body 19 and the left and right folding bodies 20 horizontally reciprocate along the bottom surface of the product 3 pushed up while stretching the film 8 by the lift 5. A carry-out belt 21 is provided which contacts the upper surface of the product 3 and moves it backward, and a guide belt 22 is provided at the rear and lower part of the carry-out belt 21 so as to be inclined.

Then, the transfer belt 2 is connected to this guide belt 22.
3, and between the transfer belts 23 there is a heat seal plate 2 for heat sealing the folded film 8.
4 are provided.

The packaged product 3 is placed at the rear end of such a transfer belt 23.
A roller 23a is provided for transferring the material to another mechanism.

Next, the film feeding body 17 and the left and right presser bodies 18
The details of the film holding mechanism provided in this section will be explained below.

First, a frame 26 to which a motor 25 serving as an electric drive unit is attached is provided on the center side.

In the case of the film feeding body 17, this frame 26 is attached to a movable body that reciprocates in the horizontal direction, and in the case of the left and right presser bodies 18, it is fixedly provided.

A sub-frame 28 is fixed to the upper part of this frame 26 via a support shaft 27 at a predetermined interval.
A fixing plate 29 is fixed to the subframe 28 and the upper edge of the frame 26.

Further, a presser body 31 is rotatably provided on the frame 26 and is urged by a tension spring 32 by means of a support shaft 30 which is suspended between the frame 26 and the sub-frame 28 .

The presser body 31 includes a top 33 that fits on the support shaft 30, an elastic plate 34 fixed on top of the top 33 and facing the fixed plate 29, and a rigid plate 35 fixed below the top 33.
It becomes more.

Further, a buffer body 36 is fixed to the top surface of the tip of the elastic plate 34.

The fixing plate 29 and the elastic plate 34 form a holding portion 31a.

Next, an arm 38 serving as a driving body is fixed to the motor shaft 37 of the motor 25, and a roller 39 provided at the upper end of this arm 38 is engaged with the lower surface of the rigid plate 35, and the arm 38 is fixed to the motor shaft 37 of the motor 25. Two protrusions 40 are integrally formed on both sides of the lower part and are deviated at a predetermined angle.

Two limit switches 41 and 42, each having its actuator positioned at the same position, are mounted below these protrusions 40 so as to overlap each other.

Next, the state of electrical connection to the motor 25 will be explained.

This motor 25 is a DC motor, and can rotate forward or reverse depending on the polarity of voltage application.

First, the motor 25 has two poles 43 and 44, a pnp transistor 46 is connected between the pole 43 and the child terminal 45, and an npn transistor 46 is connected between the pole 43 and the child terminal 45. Transistor 48 is connected.

Further, a pnp type transistor 49 is connected between the pole 44 and the child terminal 45, and an np type transistor 49 is connected between the pole 44 and the child terminal 45.
An n-type transistor 50 is connected.

The base of the transistor 46 is connected to the pole 44, and the base of the transistor 49 is connected to the pole 43.

The base of the transistor 48 is connected to the child terminal 45 via the a terminal of the limit switch 43 and a switch 51 whose opening/closing is controlled by an external camshaft, and the base of the transistor 50 is connected to the a terminal of the limit switch 41 and the external terminal. It is connected to the child terminal 45 via a switch 52 whose opening and closing are controlled by a camshaft.

Further, a brake circuit 55 including a pnp type transistor 53 and a capacitor 54 that controls the ON time of the transistor 53 is connected between the b terminal of the limit switch 41 and the base of the transistor 48.

Further, a brake circuit 58 including a pnp transistor 56 and a capacitor 57 for controlling the ON time of the transistor 56 is connected between the b terminal of the limit switch 42 and the base of the transistor 50.

In such a configuration, the general operation from when the product 3 is carried in, wrapped with the film 8, and carried out will be first explained.

Here, the products 3 are food items etc. stored in a tray with an upward opening, and the products 3 are sequentially fed onto the carry-in section 4 by an operator.

The product 3 is sent onto the lift 5 by this carry-in section 4, but first, the slide plate 7 is moved onto the lift 5 as shown in FIG.
When the slide plate 7 is moved back as shown in FIG. 3, the product 3 is placed on the lift 5 with its position and direction determined by the stopper 6. be placed in place.

At the same time, the film feeder 17 advances rearward at the timing shown in FIG. 2 and grips the film 8 slightly protruding from the film holder 12, and at the timing shown in FIG. 3, the film feeder 17 moves forward. The left and right pressers 18 grip both sides of the film 8, the film presser 15 rotates and holds the film 8 between it and the receiving plate 14, and the cutter 16 operates to feed the film 8. Cut to specified dimensions.

Next, as shown in FIG. 4, the lift 5 rises and pushes up the stretched film 8 from below, positioning the top surface of the product 3 directly below the carry-out belt 21, and separating the front folding body 19, reverse movement, and left and right folding bodies. 20 is simultaneously moved towards the center so that the front and side parts of the film 8 are folded onto the bottom of the article 3.

At this time, the film 8 is released from being gripped by the film feeder 17 and the left and right pressers 18.

When the front folding body 19 and the left and right folding bodies 20 enter the lower part of the product 3 in this way, the product 3 is lifted above the top surface of the lift 5, and the top surface of the product 3 is joined to the carry-out belt 21. be done.

Therefore, as shown in FIG. 5, the film presser 15 returns to a free state, and the rear part of the film 8 is folded into the bottom surface of the product 3 by the guide belt 22, and then transferred to the transport belt 21 by the unloading belt 21. 23, the folded film 8 is welded on a heat seal plate 24 and conveyed to a required position via rollers 23a.

Next, although the timing of holding and releasing the film between the film feeder 17 and the left and right presser members 18 is as described above, the operation of the presser portion 31a will be explained.

First, what is shown in FIG. 6 and FIG.
It is assumed that the terminal a is in an open state, the limit switch 42 is pressed and switched to the b terminal side, and the limit switch 41 is switched to the a terminal side.

Therefore, when the timing for sandwiching the film 8 comes, the switch 52 is closed by a camshaft (not shown), and the transistor 50 is closed.
In order to turn on the transistor 46, the transistor 46 is also turned on, and current flows from the poles 43 to between the poles of the motor 25, causing it to rotate in the forward direction.

As a result, the arm 38 rotates to rotate the presser body 31, and the film 8 is held between the presser portion 31a.

Since this clamping state is achieved by bending the elastic plate 34, the clamping force gradually increases.

Then, when the arm 38 rotates by a predetermined angle, the limit switches 41 and 42 are switched. In particular, since the limit switch 41 is on the terminal side, the transistor 48 is turned on via the transistor 53, and thereby the transistor 49 is turned on. Therefore, a current flows in the reverse direction from the pole 44 to the pole 43 to the motor 25.

Therefore, the brake is applied to the motor 25 rapidly and the motor 25 is stopped.

When the charging potential of the capacitor 54 reaches a predetermined value, the transistor 53 is turned off and the current flowing in the reverse direction is interrupted.

Then, after a predetermined period of time has elapsed, the switch 52 opens, and then the transistor 48 with the switch 51 closed becomes ONL.
, this causes the transistor 49 to turn on and the motor 25 to turn on.
A current flows from the pole 44 to the pole 43, causing reverse rotation, releasing the grip of the film 8, and stopping the brake at a predetermined position as in the case described above.

At this time, the presser body 31 is rotated back, but since the elastic plate 34 is present, the holding force of the film 8 gradually weakens.

Therefore, as described above, when the front folding body 19 and the left and right folding bodies 20 enter the bottom of the product 3 and fold the product 3, the resistance by the presser portion 31a gradually decreases, and when the film is folded, the product 3 The film 8 on the top surface will not become loose.

In this invention, as mentioned above, an elastic plate is provided on the presser body that presses the film between it and the fixing plate, and it is driven by an electric drive, so that the film clamping force increases gradually, and when released, it gradually increases. As a result, there is resistance when folding the film, which allows the film to be stretched under tension, ensuring complete packaging, and because it is electrically driven, drive noise is reduced. This has the advantage that the device can be made smaller without the need for any other device.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show one embodiment of this invention, and FIGS. 1 to 5 are longitudinal sectional side views showing the packaging process, FIG. 6 is a front view of the main parts, and FIG. 7 is a front view of the main parts. FIG. 8 is a vertical side view of the film in a state in which the film is clamped, and FIG. 9 is an electric circuit diagram. 8...Film, 25...Motor (electric drive unit), 26...Frame, 29...
...fixing plate, 31...presser body, 34...
...Elastic plate, 35...Rigid plate, 38...
・Arm (driving body).

Claims (1)

[Scope of utility model registration request] A fixing plate is formed integrally or separately on the frame, and a presser body is provided on the frame, which includes an elastic plate facing the fixing plate and a rigid plate integrally formed with a space between the elastic plates. The fixing plate and the elastic plate form a holding part that clamps the film, and an electric drive unit drives a driving body that engages with the rigid plate of the holding body and drives the holding body. A film pressing device for a packaging machine, characterized in that it is connected to.