JP2007030898A - Packaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging apparatus which performs a beautiful packaging with less wrinkles without measuring a film tensile force even when the size and/or the shape of a commodity is unknown. <P>SOLUTION: According to the packaging apparatus, the commodity M is pushed up from the underside a film F stretched over a packaging station S, and a folding member 205 folds the film F toward the bottom face side of the commodity M. The packaging apparatus is equipped with a motor which rotates at a preset torque limit value or lower value to reciprocate the folding member 205, a detecting means which detects a travelling speed of the folding member 205, and a controlling means which controls packaging operation based on a travelling speed detected by the detecting means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a packaging device that pushes up and packages a product from below a film stretched on a packaging station.

This type of packaging apparatus wraps the product by folding the film to the bottom surface side of the product with left and right and front and rear folding members. In such a packaged product, in order to package the product with a good appearance, it is important to package the film with no wrinkles. The following Patent Document 1 is known as an apparatus that realizes packaging that does not easily cause wrinkles.
JP-A-2001-97309 (summary)

  In the invention of Patent Document 1, the tension of the film during the packaging operation is measured, and the release timing of the film holding and the folding timing of the film are controlled based on the measured tension. According to this prior art, even when the size of the tray and the shape of the product are not known, packaging with less wrinkles becomes possible by preventing the tension of the film from being too small or excessive.

  However, in order to measure the tension of the film, it is necessary to measure a load generated on a film clamp, a folding member, or the like. This complicates the mechanism and increases the cost.

  Therefore, the main object of the present invention is to perform beautiful packaging with less wrinkles without measuring film tension even when the size and shape of the product are not known in the packaging device.

On the other hand, in the case of a soft tray or the like, when the film tension is excessive, the shape of the tray may be broken by the film tension.
Therefore, another object of the present invention is to provide a packaging device that can control the tension of a film in accordance with a commodity.

  In order to achieve the above object, a packaging apparatus according to the present invention is a packaging apparatus in which a product is pushed up from below a film stretched on a packaging station, and the film is folded to the bottom surface side of the product by a folding member. Based on the moving speed detected by the detection means, a motor for rotating the folding member in a reciprocating manner, detecting a moving speed of the folding member, and a moving speed detected by the detecting means. Control means.

According to the first aspect of the present invention, since the motor is rotated below the predetermined torque limit value, it is possible to prevent the film tension from being significantly increased. Moreover, when the folding member comes into contact with the film and the film is folded, the tension of the film increases and the moving speed of the folding member decreases. In this way, by detecting the decrease in the moving speed, it is possible to perform gentle packaging in which the tray or the like is not easily damaged without detecting the film tension.
Further, unlike the detection of the film tension, the moving speed of the folding member can be detected by a simple device, for example, by detecting a speed corresponding to the moving speed, such as the rotational speed of a motor. Therefore, there is no possibility that the mechanism becomes complicated or the cost increases.

In the first aspect of the invention, it is preferable to control the torque of the motor based on the timing at which the moving speed detected by the detecting means becomes smaller than a predetermined value.
According to this aspect, by controlling the torque of the motor, it is possible to control the operation of the folding member and suppress the occurrence of excessive tension on the film. Therefore, a more beautiful packaging finish can be expected.

According to the first aspect of the present invention, there is further provided a clamp that sandwiches both side edges of the film, and the opening timing of the film by the clamp is based on the timing when the moving speed detected by the detecting means becomes smaller than a predetermined value. Is preferably controlled.
According to this aspect, by controlling the clamp release timing in accordance with the moving speed, it is possible to suppress the generation of excessive tension on the film, and therefore, a more beautiful packaging finish can be expected.

  In this 2nd invention, in the packaging apparatus which pushes up a product from below the film stretched on the packaging station and folds the film to the bottom side of the product by the folding member, the motor for reciprocating the folding member, and the folding member The motor is rotated below the first torque limit value for a predetermined second period after the elapse of the predetermined first period after starting to move downward of the product, and the second period Control means for rotating the motor at a second torque limit value that is greater than the first torque limit value in a third period after elapse of.

  For example, when the approximate timing of the folding member contacting the film is known, the film tension may be excessive even if the moving speed of the folding member or the tension of the film is not detected, for example, by sequential operation. Can be suppressed.

According to a third aspect of the present invention, there is provided a packaging apparatus in which a product is pushed up from below a film stretched on a packaging station, and the film is folded to the bottom surface side of the product by a folding member. And a control means for rotating at a torque limit value equal to or less than a predetermined value according to.
In the third aspect of the invention, if the type of tray is known in advance, for example, in the case of a soft tray, damage to the tray can be suppressed by reducing the torque limit value.

  In the fourth invention, in the packaging device that pushes up the product from below the film stretched on the packaging station and folds the film to the bottom surface side of the product by the folding member, the motor for reciprocating the folding member while changing the torque And detecting means for detecting the torque of the motor, and a control unit for controlling the operation of the folding member based on the timing at which the torque detected by the detecting means reaches a predetermined value.

  In the fourth invention, when the folding member comes into contact with the film and the film is folded, the tension of the film increases and the torque of the motor that moves the folding member increases. Therefore, even if the film tension is not detected, the increase in the torque of the motor is detected so that the torque of the motor for moving the folding member is maintained at an appropriate value so that the tray is not easily damaged. Can do. In addition, unlike the detection of film tension, the motor torque is generally detected, so that it can be detected with a simple device. Therefore, there is no possibility that the mechanism becomes complicated or the cost increases.

  According to the fifth aspect of the present invention, in the packaging device that pushes up the product from below the film stretched on the packaging station and folds the film to the bottom surface side of the product by the folding member, the clamp that sandwiches both side edges of the film, and torque A motor for reciprocating the folding member while changing the angle, a detecting means for detecting the torque of the motor, and opening of the film by the clamp based on a timing at which the torque detected by the detecting means reaches a predetermined value. Control means for controlling the timing.

  In the fifth invention, when the folding member comes into contact with the film and the film is folded, the tension of the film increases and the torque of the motor that moves the folding member increases. Therefore, even if the film tension is not detected, by detecting the increase in the torque of the motor, it is possible to know the appropriate timing for opening the clamp and appropriately control the opening timing. Packaging that is difficult to break can be performed. Unlike film tension detection, motor torque is generally detected and can be detected with a simple device. Therefore, there is no possibility that the mechanism becomes complicated or the cost increases.

Hereinafter, the packaging device concerning Example 1 of the present invention is explained according to a drawing.
In the following description, the product M is transported on the tray T. The “product M” refers to the contents in the tray T and the concept including the contents and the tray T. There are cases. Moreover, in the following description, the tray T in which the contents are accommodated will be described as an example of the product. However, the product may be a product that is not placed on the tray T.

First, the basic structure and operation of the packaging device will be described.
As shown in FIG. 1, the present packaging device is a packaging device that carries products from the front side 2a and packages them, and then discharges them to the front side 2a. The front surface 2a is provided with a supply device 20 such as a conveyor. It is.

  In FIG. 2, the supply device 20 supplies a tray (packaged object) T on which the contents M are placed onto a lifter (elevator mechanism) 201. Each post 210 of the lifter 201 is disposed immediately below a packaging station (packaging section) S of the packaging mechanism 200 and can be moved up and down by an elevating means 208. When the tray T is supplied from the supply device 20, the lifter 201 rises and lifts the tray T to the packaging station S.

On the other hand, the stretched film F is supplied to the packaging station S by a pair of conveying belts 3 and 3 prior to the packaging operation. The film F comes into close contact with the upper surface of the tray T when the tray T is pushed up. In this state, the film folding mechanism 203 includes a pair of left and right folding plates (folding members) 204, 204, a rear folding plate (folding member) 205, a round bar-shaped front folding rod 206, and a pusher 207 (see FIG. 3). 2), the side edges of the front, rear, left and right sides of the film F are folded and packaged on the bottom side of the tray T, and the packaged tray T is conveyed onto the heat welding conveyor 10 of FIG. The heat welding conveyor 10 welds the films F folded on the bottom surfaces to each other, and then the tray T is discharged onto the discharge table 209 in FIG.
A label is pasted on the packaged product M to be discharged by the label pasting machine 12.

Film supply mechanism:
As shown in the schematic cross-sectional view of FIG. 4, on both sides in the left-right direction Y of the present apparatus, a pair of a film supply mechanism including a film transfer means 5 and a cutting device 6 and a film roll Fr are provided. One of the left and right film supply mechanisms is selected, and the film F is supplied to the packaging station S by the transport belts (supply means) 3 and 3.

  The film transfer means 5 transfers the film F drawn from the film roll Fr to the transport belts 3 and 3. The conveyance belts 3 and 3 sandwich both side edges Fe (FIG. 5) along the conveyance direction Y of the film F, and draw out the film F toward the packaging station S.

The film supply mechanism is generally symmetrical, and in the following description, the right part will be mainly described.
The film passing means 5 includes a pair of film insertion plates 51 and 52 and a plurality of one-way rollers 53 supported by the film insertion plate 51.
The film insertion plates 51 and 52 move up and down while sandwiching the leading end side of the film F passed to the conveyor belts 3 and 3. The film insertion plates 51 and 52 rise from the retracted end position P1 and pass the film front end F2 to the conveyor belts 3 and 3.

  Each of the conveyor belts 3 and 3 includes two sets of a lower drive belt 31, an upper driven belt 32, and an introduction belt 33 at the front and rear. The introduction belt 33 sandwiches the film F fed from below by the film passing means 5 between the upstream end of the lower drive belt 31 and holds the film F between the lower drive belt 31 and the upper driven belt 32. Lead between.

  The cutting device 6 includes a cutter 61 and a chopping base 62. The cutter 61 contacts the chopping base 62 and cuts the film F.

Packing station S:
FIG. 5 is a schematic plan sectional view of the packaging station S. FIG.
As shown in FIG. 5, two sets of clamping devices 7b and 7f are provided corresponding to the conveyor belts 3 and 3, respectively. The clamping devices 7b and 7f are arranged so that the film F transported to the predetermined packaging position of the packaging station S by the transport belts 3 and 3 is located inside the transport belts 3 and 3 near the side edge Fe of the film F. Clamp.

Clamp devices 7b, 7f:
6 shows a side view of the packaging station S, and FIG. 7 shows a cross-sectional view taken along line VII-VII in FIG.
As shown in FIGS. 6A and 7A, the clamp devices 7b and 7f include a movable clamp plate 74a and a fixed clamp plate 74b. As shown in FIG. 7, the clamps 7b and 7f are constituted by central clamps 7bc and 7fc and left and right clamps 7bs and 7fs provided on both sides thereof.

  The movable clamp plate 74a can be moved up and down, and is provided in a plurality of divisions in the transport direction Y of the film F. The fixed clamp plate 74b is a belt-like plate fixed below the movable clamp plate 74a. When the movable clamp plate 74a is moved up and down by a driving machine (not shown) (for example, a solenoid valve), the movable clamp plate 74 is released from a slightly separated state from the fixed clamp plate 74b, as shown in FIGS. It is set to the clamping state where the film F is clamped between the movable clamp plate 74a and the fixed clamp plate 74b shown in a) to (d).

  The belts 31 to 33 of the conveyor belts 3 and 3 in FIG. 4 are rotationally driven, and the film F is transferred between the lower drive belt 31 and the upper driven belt 32, whereby the film F is pulled out from the film roll Fr. The film F cut by the cutting device 6 is conveyed to a predetermined packaging position by belts 31 and 31, as shown in FIG. After the conveyance, the clamp devices 7b and 7f in the opened state are held, and the film F is held in the packaging station S in a stretched state.

  The tray T is lifted to the packaging station S by the lifter 201 shown in FIG. By this lifting, the film F adheres to the upper surface of the tray T as shown in FIGS. In this state, as shown in FIGS. 6B to 6D, the rear folding plate 205 moves forward. On the other hand, as shown in FIGS. 7B to 7D, the left and right folding plates 204, 204 move so as to be close to each other. Thereafter, as shown in FIGS. 6E and 7E, the clamping devices 7b and 7f are opened, and the tray T is packaged.

Equipment configuration:
As shown in FIG. 8, the packaging apparatus includes a microcomputer (a microcomputer: control means) 40. The microcomputer 40 includes a CPU 40a, a memory 40b, and a timer 40c for measuring time. The memory 40b stores first torque limit values α1, β1 and second torque limit values α2, β2, which will be described later. The microcomputer 40 controls the first, second and other motors 42 ₁ , 42 ₂ , 45 _i and the electromagnetic valve 49 _i .

The forward and reverse rotation of the first motor 42 _1, via a transmission mechanism (not shown), a rear folding plate 205 (FIG. 6) is reciprocated in the longitudinal direction X. The first motor 42 ₁ is connected to the microcomputer 40 via a first drive circuit 41 ₁ such as a motor driver.
The forward and reverse rotation of the second motor 42 _2, the left and right folding plates 204, 204 via a transmission mechanism (not shown) (FIG. 7) is reciprocated in the lateral direction Y. The second motor 42 ₂ is connected to the microcomputer 40 via a second drive circuit 41 ₂ such as a motor driver.

As the first and second motors 42 ₁ and 42 ₂ , for example, motors capable of torque control by controlling current values via drive circuits 41 ₁ and 41 ₂ are used. Specifically, for example, a DC brushless motor or the like can be used as the motors 42 ₁ and 42 ₂ .

₁ the first and second motor 42, 42 is _2, for example, first and second detecting means consisting of a rotary encoder 43 _1, 43 ₂ are respectively provided. The detection means 43 ₁ and 43 ₂ detect the number of rotations (number of pulses) per unit time of the motors 42 ₁ and 42 ₂ , respectively, and transmit them to the microcomputer 40.

Other devices such as the lifter 201, the pusher 207, the conveyor belt 3, and the tray presser (not shown) are driven by the other motor 45 _i via the other drive circuit 44 _i .

The electromagnetic valve 49 _i is connected to the microcomputer 40 via a valve drive circuit 48 _i . By operating the electromagnetic valves 49 _i , the movable clamp plate 74a moves up and down to control the clamp devices 7b and 7f in an open / clamped state.

Packaging operation:
In the open state in which the clamp plates 74a and 74b in FIG. 5 are opened, when the leading edge of the film F enters between the lower drive belt 31 and the upper driven belt 32 by the film transfer means 5 in FIG. The film F is pulled out from the film roll Fr by the belts 31 and 32. When the length of the film F reaches a predetermined cut length by this drawing, the film F is cut by the cutting device 6.

  As shown in FIG. 5, the cut film F is conveyed to a predetermined packaging position of the packaging station S (for example, the center of the packaging station S) by the belts 31 and 31.

  After that, as shown in the timing chart of FIG. 9, the packaging operation is performed based on the predetermined timing by each device provided in the apparatus. However, for the sake of simplification of description, the operation of each device is individually described. To do.

Operation of the rear folding plate 205:
Figure 10 is a graph showing the displacement of the rear folding plate 205, a relationship between the first motor 42 ₁ of the torque in accordance with the wrapping cycle.
As shown in FIG. 9, the lifter 201 starts to rise at the timing T0, and the packaging cycle starts. In timing T1 after the short time, the first period P1 starts with operation of the first motor 42 _1, the folding plate 205 after the FIGS. 6 (a) initiating forward toward the tray T.

As shown in FIG. 10, in the first period P1, until the rear folding plate 205 reaches a predetermined maximum speed, the first motor 42 ₁ of the torque once, after rising to a maximum value Max1, a rear folding plate Since 205 moves at a constant speed, it falls to the first torque limit value α1 or less.

When a preset time elapses after the timing T1, the second period P2 starts at the timing T2, and in the second period P2, the first motor 42 ₁ is rotationally driven at the first torque limit value α1 or less. As shown in FIG. 6 (b), the rear folding plate 205 that moves forward at the first torque limit value α1 or less in the second period P2 is further increased after contacting the film F as shown in FIG. 6 (c). Continue moving. As shown in FIG. 6 (d), the tension (elongation) of the film F increases, and then the rear folding plate 205 is stopped or significantly decelerated at timing T5 in FIG. The resistance of the film F, the first motor 42 ₁ of torque with increases to the first torque limiting value [alpha] 1, generally the first motor 42 ₁ is rotated at a constant torque, the moving speed of the rear folding plate 205 is lowered .

The microcomputer 40 of FIG. 8 is based on the detection signal from the first detecting means 43 _1, after the post-folding plate 205 is in contact with the film F, by the tension of the film F, in the second period P2, the rear folding plate 205 When it is determined that the forward speed is less than or equal to the predetermined speed, the timer 40c is caused to start measuring time. When a predetermined minute time ΔT (FIG. 9) elapses after the start of time measurement, the third period P3 starts at timing T6 in FIG.

In the third period P3, the first motor 42 ₁ is rotationally driven by the microcomputer 40 below the second torque limit value α2 that is larger than the first torque limit value α1. Therefore, as shown in FIG. 6 (e), the rear folding plate 205 resumes (or continues) the forward folding, and the folding of the film F below the tray T is resumed (or continued). The second torque limit value α2 is set to a value smaller than or equal to the maximum value Max1.

Thereafter, after the folding is finished and the rear folding plate 205 is stopped, the fourth period P4 shown in FIG. 10 is entered. After the fourth period P4, as shown in FIG. 9, the return operation of the rear folding plate 205 to the origin position is performed to prepare for the next packaging operation. Note that above for the fourth period P4, so that it can return towards the starting point at a high speed, thereby rotating the first motor 42 ₁ without a limit value of the torque in the opposite direction.

Thus, when folded the film F, are driven by the first torque limit value α1 following first motor 42 ₁ is less torque value, when the film F is folded by the rear folding plate 205, the tension of the film F Is increased, the rear folding plate 205 is stopped or remarkably decelerated. After this stop or deceleration, with opening the clamping device, greater than the first torque limiting value [alpha] 1, and resume the packaging by rotating the first motor 42 ₁ in the second torque limit value α2 smaller than the maximum value Max1 To do. Therefore, it can prevent that the tension | tensile_strength of the film F increases remarkably. Therefore, even if the film tension is not detected, it is possible to perform gentle packaging in which the tray T and the like are not easily damaged.

Further, unlike the case of detecting the film tension, the moving speed of the rear folding plate 205 can be detected with a simple device by detecting the rotation speed of the first motor 42 ₁ by the first detection means 43 _1. . Therefore, there is no possibility that the mechanism becomes complicated and the cost increases.

Operation of the left and right folding plates 204, 204:
For the left and right folded plates 204, 204, the same torque control as that of the rear folded plate 205 is performed.
Figure 11 is a graph showing the displacement of the left and right folding plates 204, 204, the relationship between the second motor 42 and _second torque in accordance with the wrapping cycle.
As shown in FIG. 11, at a predetermined timing T2 of the first period P11, the second motor 42 ₂ starts operating, starts to move in a direction lateral folding plates 204, 204 are close to each other in FIGS. 7 (a) To do.

As shown in FIG. 11, in such a first period P11, after the left and right folding plates 204, 204 is a second motor 42 _{and second} torque to reach a predetermined maximum speed, once elevated to the maximum value Max2, left and right Since the folding plates 204 and 204 move at the same speed, the folding plates 204 are lowered to the first torque limit value β1 or less. Note that the second torque limit value β2 of the first torque limit value β1 and later for the second motor 42 _2, the first motor 42 of the _first and second torque limit value α1 of the folding plate 205 after the above-mentioned, [alpha] 2 Is set to a different value.

Then, in the second period P12 of time T3 after the second motor 42 ₂ is driven below the first torque limit value .beta.1. In the second period P12, the left and right folded plates 204, 204 that move to the left and right at the first torque limit value β1 or less continue to move even after contacting the film F, as shown in FIG. As shown in FIG. 7 (d), the tension of the film F increases, and eventually, at the timing T4 in FIG. 11, the moving speed of the left and right folding plates 204, 204 is stopped or significantly reduced.

Thereafter, the timing T6 to third period P13 is started at (timing T6 based on the control of folding plates 205 after the above-mentioned), the second motor 42 ₂ is the second torque limit is greater than the first torque limit value β1 of Figure 11 Rotation is driven at a value β2 or less, and as shown in FIG. 7E, folding of the film F downward on the tray T is continued.

Operation of the clamping device 7b (7f):
As shown in FIG. 5, after the packaging operation is started in a state where all the clamp devices 7b and 7f are clamping the film F, at the timing T6 in FIG. 9, the front left and right clamps 7fs and the rear The left and right and center clamps 7bc, 7bs are opened. Thereafter, at the timing T8 in accordance with the movement of the pusher 207, the front center clamp 7fc is opened, and the packaging is completed when the pusher 207 moves to the forward end.

Thus, the moving speed of the folding plate 205 after being detected by the first detecting means 43 _1, after becoming smaller than a predetermined value, based on the timing T6 when the predetermined minute time ΔT has elapsed, the clamping device 7b , 7f controls the opening timing of the film F.

Accordingly, the release timing of the clamp devices 7b and 7f is controlled in accordance with the fluctuations in the torques of the first and second motors 42 ₁ and 42 ₂ , so that excessive tension can be prevented from being generated in the film F. For this reason, a more beautiful packaging finish can be expected.

Tray presser:
The tray T is pressed from above by a tray presser (not shown) at a timing T7 immediately after the timing T6 at which folding by the folding plates 204 and 205 starts. This is to ensure that the film F is folded by the folding plates 204 and 205. In addition, as a result, the tray T is pressed from above when passing through the heat welding conveyor 10, and the film is reliably welded.

Other equipment:
Note that, as shown in FIG. 9, other devices may be controlled based on the timing T6 and the like. Examples of other device control operations include the discharge timing of the pusher 207 and the lowering timing of the lifter 201. The front and rear transport belts 3 and the clamp devices 7b and 7f are controlled so as to move back and forth according to the packaging operation and slightly relax the tension of the film F.

  That is, as shown in FIGS. 6A to 6E, the front conveyor belt 3f and the clamp device 7f are moved rearward (toward the center of the packaging station S), while the rear conveyor belt 3b is moved. And the clamping device 7b is moved forward (towards the center of the packaging station S). The movement timing and movement distance of the conveyor belt 3 and the clamp device 7b may be controlled based on the timing T6 and the like.

  In the above-described first embodiment, the third period P3, P13 starts at the timing T6 based on the fact that the forward speed of the rear folding plate 205 is equal to or lower than a predetermined speed. Instead of using the plate 205 as a reference, the third period may be started on the basis of the case where the left and right folding plates 204, 204 stop or become below a predetermined speed.

12 and 13 show a second embodiment.
As shown in FIG. 12, a camera 2 for imaging the tray T is provided above the supply device 20. As shown in FIG. 13, the camera 2 is connected to the microcomputer 40 via an interface (not shown), and an imaging signal from the camera 2 is transmitted to the microcomputer 40.
In the memory 40b, in addition to the storage unit for the first torque limit values α1, β1 and the second torque limit values α2, β2, the timing at which the torque limit values α1, α2, β1, β2 should be operated is traced. The timing memory | storage part 40e memorize | stored according to the kind of is provided.

  The memory 40b is provided with a product information storage unit 40d. The product information storage unit 40d stores various product information and dimensions for each tray T. The microcomputer 40 calculates the approximate size of the tray T based on the image pickup signal from the camera 2 and identifies the type of the tray T.

Based on the type of the tray T, the microcomputer 40 reads the timing at which the rear folding plate 205 and the left and right folding plates 204, 204 are operated below a predetermined torque limit value from the timing storage unit 40e. The microcomputer 40 rotates the motors 42 ₁ and 42 ₂ of the folding plates 204 and 205 according to the timing.

  As described above, when the dimensions of the tray T can be specified in advance, without detecting the moving speed of the folding plates 204 and 205 and the tension of the film F, the folding plates 204 and 205 can be detected at a predetermined timing. Torque control can be performed. Therefore, it is possible to perform packaging that is friendly to the tray T while shortening the cycle time, and to suppress an excessive film tension.

By the way, when the shape, type, material, and the like of the tray T are known in advance, for example, in the case of a so-called soft tray made of a soft material or a thin material, the first and second torque limit values are reduced. By performing the adjustment, it is possible to suppress the damage of the tray T.
Further, the torque control value may be changed according to the ambient temperature, humidity, film stretch rate (ratio of stretching film), and the like.

  The CPU 40a may calculate the timing for moving the folding plates 204 and 205 at a high speed and the torque limit value each time until the folding plates 204 and 205 come into contact with the film F each time. .

In Examples 1 and 2 above, on the basis of the moving speed of the folding plates 205 and the lateral folding plates 204, 204 after being detected by the first and second detection means 43 _1, it was decided to perform the control of each device However, in the third embodiment, each device is controlled based on a change in torque of the first motor 42 ₁ and / or the second motor 42 ₂ that reciprocates the rear folding plate 205.

As shown in FIG. 14, the first motor 42 _1, the torque detection means 46 is provided. Torque detection means 46 is for performing torque detection of the first motor 42 ₁ of the drive shaft. Such torque detecting means 46, for example, by detecting a change in magnetic resistance, a commercially available can be used torque sensor for detecting a first motor 42 ₁ of the torque, for example, disclosed in JP-A-10-028354 Has been.
The torque detection means 46 transmits the detected torque detection value of the first motor 42 ₁ to the microcomputer 40.

Figure 15 is a characteristic diagram showing the displacement of the rear folding plate 205, a relationship between the first motor 42 ₁ of the torque in accordance with the wrapping cycle.
As shown in FIG. 15, the wrapping cycle at a timing T0 is started, at a predetermined timing T1 is the initial first period P1, the first motor 42 ₁ starts to operate, folding plate after FIGS. 6 (a) 205 begins to advance toward tray T.

As shown in FIG. 15, in the first period P1, the first motor 42 ₁ of the torque once, after rising to a maximum value Max1, because the rear fold plate 205 is moved at a constant speed, the first torque limit value α1 Descend to:

Thereafter, in the second period P2 after the timing T2, the first motor 42 ₁ is driven at the first torque limit value α1 or less. As shown in FIG. 6 (b), the rear folding plate 205 that moves forward at the first torque limit value α1 or less in the second period P2 is further increased after contacting the film F as shown in FIG. 6 (c). Continue moving. Eventually, at time T5A in FIG. 15, the first motor 42 ₁ torque rises to a predetermined threshold value SH. The threshold value SH is set to a value equal to or less than the first torque limit value α1.
Thereafter, the rear folding plate 205 continues to advance, and the tension of the film F increases and is stopped or decelerated.

On the other hand, the microcomputer 40 of FIG. 8 is based on the torque signal from the torque detection means 46, the rear after the folding plate 205 is in contact with the film F, the by the tension of the film F, the first motor 42 ₁ torque is a predetermined threshold value When it is determined that the temperature has become equal to or higher than SH, the timer 40c is started to measure time. When a predetermined minute time ΔT elapses after the start of the time measurement, the third period P3 starts at the timing T6 in FIG. 10, and the first motor 42 ₁ is rotationally driven at the second torque limit value α2 or less.
Since the subsequent operation is the same as that of the first embodiment, the description thereof is omitted.

Thus, the rear folding plate 205 when in contact with the film F is folded film F, along with the tension of the film F is increased, the first motor 42 ₁ of torque increases. Therefore, even if the tension of the film F is not detected, the torque of the first motor 42 ₁ that moves the rear folding plate 205 is maintained at an appropriate value by detecting the increase in the torque of the first motor 42 _1. Further, it is possible to perform packaging in which the tray T or the like is not easily damaged.

As shown in the timing chart of FIG. 16, the left and right folding plates 204, 204 and clamping device 7b, for also 7f, the timing T6 to the first motor 42 ₁ torque is timed based on the timing reaches a predetermined threshold value SH Controlled based on. Therefore, the second motor 42 _{and second} torque and to control to an appropriate value to move the left and right folding plates 204 and 204, it is possible to perform clamping device 7b, the timing of opening of 7f properly.

In the embodiments described above, the moving speed and the rear folding plate 205, it is assumed that the control is performed based on the first motor 42 ₁ of torque for driving the rear folding plate 205, the control right folding plate 204 , 204 moving speed or may be performed on the basis of the second motor 42 _{and second} torque for driving the left and right folding plates 204, 204.

In each of the above-described embodiments, the torque values of the motors 42 ₁ and 42 ₂ are set in three stages of the maximum value Max and the first and second torque limit values, but the maximum value Max and the first torque value 2 You may make it control in steps, may be four steps or more, and may set in a non-step.

Heater guard 81:
Incidentally, as shown in FIGS. 17A and 17B, the heat welding conveyor 10 is provided with a heater 80. Since the heater 80 is heated, a heater guard 81 is provided to protect the hand from the heat of the heater 80 when an operator puts his / her hand inside the apparatus, such as during label replacement. In the state where the power OFF, the cover open, and the emergency stop are pushed, the heater guard 81 is in the shielded state where the heater guard 81 is raised as shown in FIG. In such a shielding state, the heater guard 81 prevents the worker from directly touching the heater 80.

  On the other hand, as shown in FIG. 17B, in the use state in which the tray is packed and discharged, the heater guard 81 is moved to the retracted state in which the heater guard 81 is lowered so as not to prevent the tray T from being discharged. Need to be moved.

Here, in the conventional packaging apparatus, when moving the heater guard 81 from the shielding state to the retracted state, two solenoids are used to obtain a sufficient stroke.
In contrast, the packaging device of the present invention uses one solenoid. As shown by the two-dot chain line in FIG. 17B, the pusher 207 pushes the heater guard 81 to move the heater guard 81 to a predetermined position, and then actuate the solenoid 82 to show the storage state indicated by the solid line. Is moved to.

  By using such a moving mechanism of the heater guard 81, a simple structure in which the heater guard 81 can be stored with a single solenoid can be achieved, and the cost can be reduced.

  The movement amount of the heater guard 81 by the pusher 207 is preferably about half of the movement stroke of the heater guard 81. This is because if the heater guard 81 is moved largely using the pusher 207, the foreign matter may be caught in the lower portion of the heater guard 81 by the pusher 207 when the foreign matter is sandwiched below the heater guard 81.

The storing operation of the heater guard 81 is preferably performed only when the tray (product) T is stabilized.
Furthermore, it is preferable to set the operation speed of the pusher 207 in two stages so that the pusher 207 is operated at a high speed at the start of operation and at a low speed immediately before the heater guard 81 is pressed. This is for the purpose of preventing damage to the heater guard 81 and mitigating impact and noise.

As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily understand various changes and modifications within the obvious scope by looking at the present specification.
For example, the clamp plate may be disposed between one loop belt and clamp the film via the belt. Also, there is no need to provide a clamp or tray presser.
Further, either the timing of opening the clamping device or the timing of torque limitation may be preceded or may be simultaneous.
Moreover, it is applicable also when packaging goods, without using a tray.
Accordingly, such changes and modifications are to be construed as within the scope of the present invention as defined by the claims.

  INDUSTRIAL APPLICABILITY The present invention can be used for a packaging device that packages products using a film drawn from a film roll.

It is a schematic perspective view of the packaging apparatus concerning Example 1 of this invention. It is a schematic side view which shows a packaging mechanism. It is a perspective view which shows the folding operation of a film. It is a schematic sectional drawing which shows the supply mechanism of a film. It is a schematic plane sectional view which shows a packaging station. It is a schematic side view of the packaging station which shows the packaging method. It is a schematic sectional drawing of the packaging station which shows the packaging method. It is a schematic block diagram of this apparatus. It is a timing chart which shows a packaging method. It is a characteristic view which shows the relationship between the displacement of a back folding plate, and the change of the torque of a 1st motor. It is a characteristic view which shows the relationship between the displacement of a right-and-left folding plate, and the change of the torque of a 2nd motor. It is a schematic side view of the packaging apparatus concerning Example 2 of this invention. It is a schematic block diagram of the packaging apparatus. It is a schematic structure of the packaging apparatus concerning Example 3 of this invention. It is a characteristic view which shows the relationship between the displacement of a back folding plate, and the change of the torque of a 1st motor. It is a timing chart which shows the packaging method. It is a schematic side view which shows the moving mechanism of a heater guard.

Explanation of symbols

7b, 7f: Clamping device 40: Microcomputer (control means)
42 ₁ : First motor 42 ₂ : Second motor 204: Left and right folding plate (folding member)
205: Rear folding plate (folding member)
F: Film P1, P11: First period P2, P12: Second period P3, P13: Third period S: Packaging station

Claims (8)

In the packaging device that pushes up the product from below the film stretched on the packaging station, and folds the film to the bottom side of the product by a folding member,
A motor that rotates below a predetermined torque limit value set in advance and reciprocates the folding member;
Detecting means for detecting the moving speed of the folding member;
A packaging device comprising: control means for controlling a packaging operation based on the moving speed detected by the detection means. In the packaging device that pushes up the product from below the film stretched on the packaging station, and folds the film to the bottom side of the product by a folding member,
A motor for reciprocating the folding member;
Detecting means for detecting the moving speed of the folding member;
During the second period until the moving speed detected by the detecting means becomes smaller than a predetermined value after the elapse of a predetermined first period after the folding member starts moving downward of the product, Control means for rotating the motor below a first torque limit value and rotating the motor below a second torque limit value that is greater than the first torque limit value in a third period after the second period has elapsed. And packaging device. In claim 1 or 2,
A packaging device, wherein the torque of the motor is controlled based on a timing at which the moving speed detected by the detecting means becomes smaller than a predetermined value. In claim 1 or 2,
A clamp that sandwiches both side edges of the film;
A packaging apparatus, wherein the timing of opening the film by the clamp is controlled based on a timing at which the moving speed detected by the detecting means becomes smaller than a predetermined value. In the packaging device that pushes up the product from below the film stretched on the packaging station, and folds the film to the bottom side of the product by a folding member,
A motor for reciprocating the folding member;
Rotating the motor below a first torque limit value for a predetermined second period after elapse of a predetermined first period after the folding member starts moving downward of the product, and A packaging device comprising: control means for rotating the motor below a second torque limit value that is greater than the first torque limit value in a third period after the elapse of the second period. In the packaging device that pushes up the product from below the film stretched on the packaging station, and folds the film to the bottom side of the product by a folding member,
A motor for reciprocating the folding member;
A packaging device comprising: control means for rotating the motor at a torque limit value equal to or less than a predetermined value corresponding to a product. In the packaging device that pushes up the product from below the film stretched on the packaging station, and folds the film to the bottom side of the product by a folding member,
A motor that reciprocates the folding member while varying the torque;
Detecting means for detecting the torque of the motor;
A packaging device comprising: a control unit that controls the operation of the folding member based on a timing at which the torque detected by the detection means reaches a predetermined value. In the packaging device that pushes up the product from below the film stretched on the packaging station, and folds the film to the bottom side of the product by a folding member,
A clamp that sandwiches both side edges of the film;
A motor that reciprocates the folding member while varying the torque;
Detecting means for detecting the torque of the motor;
A packaging device comprising: control means for controlling the timing of opening the film by the clamp based on the timing when the torque detected by the detecting means reaches a predetermined value.

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