JP3525361B2 - Packaging equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging apparatus for wrapping a product with a stretch film. 2. Description of the Related Art Generally, when a large amount of fresh foods such as fruits and meats are packed and packaged for a supermarket, a packaging device for automatically and continuously packaging products placed on a tray made of foamed resin with a film. Is used. In this apparatus, first, a product with a tray on which a product is placed is conveyed and placed on a table of a motor-driven elevator mechanism. The product with the tray is pushed upward by the motor driving force of the elevator mechanism. Above this, the film cut to a predetermined length is transported to the packaging position and stretched. When the tray-equipped product rises, it hits the stretched film at the packaging position and is further pushed up. The left and right and front and rear ends of the film that covers the cover are folded into the bottom of the tray and packaged. Thereafter, the product with the tray packed in the film is discharged. In this case, when the elevator mechanism starts,
If the acceleration at the time of stop is large, the posture of the arranged products may collapse and the appearance of the products may be deteriorated, or the tray may be crushed. The acceleration of the table near the dead center or the bottom dead center is set to have an appropriate value. [0005] However, in a conventional packaging apparatus using a cam, if the speed of the packaging machine changes, the acceleration of the elevator mechanism also changes accordingly. However, there is a problem that the speed of the packaging machine has to be limited, and therefore, the operation efficiency is deteriorated. Further, when the table of the elevator mechanism is lifted, the pushing force of the table applied to the stretched film is constant even if the rising speed near the stretched film is reduced by the shape of the cam. Depending on the type of the product, the tray may be damaged due to the tension of the stretched film, or sometimes the product in the tray may dance and the product cannot be wrapped in the film. In such a case, it is necessary to remove the tray that has failed to be wrapped, and there has been a problem that the operating efficiency of the packaging device is reduced. [0007] Further, when the following commodity with a tray is dropped on the lower part of the table of the elevator mechanism due to a mistake in carrying in descending, the commodity with the tray gets into the elevator mechanism. This type of packaging equipment performs cycle control.If the table does not return to the home position in the cycle time, an alarm buzzer is activated.In that case, the elevator mechanism pushes the tray until the alarm buzzer is activated. If the product is a minced meat or the like, the tray is damaged and the product splatters, which has a problem that it is extremely difficult to remove the product. The present invention solves the above-mentioned problems and provides a packaging apparatus which can prevent damage to goods and trays regardless of the combination of goods and trays and can easily improve operation efficiency. It is an object. [0009] In order to achieve the above object, a packaging apparatus according to claim 1 comprises a conveying means for conveying goods,
An elevator mechanism that pushes the conveyed product by the driving force of the motor, a transfer mechanism that is located above the elevator mechanism, and that transfers the film to the packaging position and stretches the film, and a film that stretches the pushed product up to the packaging position. To
Further, a film folding mechanism for folding the left and right and front and rear ends of the film covering the upper portion of the pushed-up product into the bottom of the product and wrapping the film, discharging means for discharging the film-wrapped product, and lifting the product to raise the product Torque limiting means for limiting the torque of the motor of the elevator mechanism to a predetermined torque limiting value or less in a torque limiting area provided between the vicinity of the film and the rising stop point or the vicinity thereof, and a plurality of types of products. Depending on,
There is provided a torque limit changing means for changing a torque limit area and a torque limit value of the torque limiting means. According to the first aspect of the present invention, the torque limiting means is provided between the vicinity of the product hitting the stretched film due to the rise of the product and the rising stop point or the vicinity thereof. In the above, the torque of the motor of the elevator mechanism is limited to a predetermined torque limit value or less. The torque limit changing unit changes the torque limit area and the torque limit value of the torque limit unit according to the types of the plurality of products. Therefore, regardless of the combination of goods and trays,
The tray or the product can be prevented from being damaged, and the operation efficiency of the packaging device can be improved. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view of a packaging device according to an embodiment of the present invention. This packaging device is provided with a product M on a tray T.
Is provided with a packaging machine 40 for film-wrapping a product TM with a tray on which a product is placed, and a pricing device 60 for applying a price label indicating the price of the product M to the product TM with a tray packed with the film. [0012] The goods TM with trays are transferred to the carry-in conveyor 54.
Is transported rightward along the X direction to the transport conveyor 42 as a transport means, and is pushed upward along the Z direction by an elevator mechanism 30 provided on the rear side along the Y direction of the transport conveyor 42. Then, the elevator mechanism 30
After the film is wrapped with a film stretched above the product M, a price label indicating the price of the product M or the like is attached by the price maker 60. Thereafter, the paper is discharged forward along the Y direction from a discharge conveyor 62 which is a discharging means (FIG. 2). FIG. 2 is a schematic sectional view of the packaging machine 40 shown in FIG. In the packaging machine 40, first, the goods TM with a tray placed on the conveyor 42 are conveyed backward B along the Y direction. In this example, the transport conveyor 42 has a weighing mechanism. This weighing mechanism has weight detecting means 9 such as a load cell, detects the weight of the commodity TM with a tray, tares a known weight of the tray T from this weight, and weighs the weight of the commodity M. I do. This conveyor 4
On the downstream side of 2, an elevator mechanism 30 is provided which receives the weighed product with tray TM at the push-up standby position P0 and pushes it up to the upper packaging position P2. Above the elevator mechanism 30, transfer mechanisms 46, 46 are provided, and the film F is moved to the packaging position P2.
It is transported to and stretched. After the product with tray TM hits the stretched film F and is further pushed up, the film folding mechanism 50 folds the left, right, front and rear ends of the film F covering the top of the product with tray TM into the bottom of the tray T, and Will be packaged. A seal mechanism 51 is disposed above the transport conveyor 42 in the front Fo along the Y direction of the film folding mechanism 50. The sealing mechanism 51 thermally seals the film F folded on the bottom side of the tray T. Pusher 52
Will forward the product TM with a film packaged tray with Fo
To send out the product M onto the seal mechanism 51. Product TM with heat sealed film packaged tray
The paper is discharged from the discharge conveyor 62 to the front Fo. FIG. 3 shows control means 20 for controlling each part of the packaging apparatus. The control means 20 is built in a personal computer 53 (FIG. 1) having the display 2 and the input means 3. Predetermined transport and packaging conditions are stored in the memory 26, and the control means 20 controls the actuators 28 of the respective components such as the rear folding plate 48 and the pusher 52 based on the conditions. Further, cycle control is performed so that a series of operations is performed in a constant cycle. If the cycle time is exceeded, an alarm buzzer (not shown) is displayed as an error display. The control means 20 includes a servo controller 22 for controlling a servo motor M1 for driving the elevator mechanism 30. The servo controller 22 further includes an operating point near the upper end and a lower end of the operating point of the elevator mechanism 30. Decelerating means 23 for controlling to decelerate the vicinity, torque limiting means 24 for limiting the torque of servomotor M1 to a predetermined torque limiting value or less in a predetermined torque limiting area, and torque limiting area and torque limiting of torque limiting means 24 A torque limit changing means 25 for changing the value is incorporated. Next, the above components will be described in detail. The transport conveyor 42 shown in FIG. 2 is stretched between a weighing mechanism having a weight detecting means 9 such as a load cell for weighing the product M and a pair of pulleys 44 supported on the upper part of the weight detecting means 9. Drive belts 45
have. Each of the drive belts 45 presses the end of the tray T to push the product M toward the elevator mechanism 30.
Is fixed. Therefore, after the weight of the placed product with tray TM is measured, the elevator mechanism 3 is moved by the claw-shaped protrusion 45a.
It is sent to the push-up standby position P0 above zero. The elevator mechanism 30 is disposed immediately below the packaging position. On the front upper surface of the base 31, two guide cylinders 33, 33 are erected between the base 31 and the frame 35 at predetermined intervals in the left and right directions, and two guide rods 36,
36 are provided so as to be vertically movable. On the upper surfaces of the lifting rods 36, 36, there is provided a table 38 on which a product TM with a tray is placed. A servomotor M1 as a drive motor is mounted on the rear upper surface of the base 31, and its rotation is transmitted to left and right output shafts 32, 32 via a gear box 39. The pinions 3 fixed to the output shafts 32, 32, respectively.
4 and 34 are engaged with rack portions 36a and 36a formed on the side surfaces of the lifting rods 36 and 36, respectively. The elevator mechanism 30 includes a control unit 20
(FIG. 3). In this example, position control is performed in which the number of pulses of an encoder (not shown) of the servomotor M1 is counted, the rotation angle is detected, and feedback is performed so as to reach the target position. When the product TM with tray is conveyed from the conveyor 42, the product TM with tray is lifted and lifted, and the product TM with tray is pressed against the lower surface of the film F held in a state of being stretched at the packaging position P2. On the other hand, a film F
It is supplied prior to the packaging operation in a state where both side edges in the width direction are sandwiched between transfer mechanisms 46, 46 such as belts. After being supplied from a film roll (not shown), the supplied film F is cut by a film cutter (not shown) according to packaging conditions such as the width and height of the tray T. Both sides of the cut film F in the depth direction (left-right direction) are held by the transfer mechanisms 46, 46,
When the product TM with tray is pushed up by the elevator mechanism 30, the product TM comes into close contact with the upper surface of the product TM with tray. In this state, the film folding mechanism 50 wraps the product M by folding the front, rear, left and right side edges of the film F toward the bottom surface of the tray T as described below. The film folding mechanism 50 includes a pair of left and right folding plates 47, 47 (only one is shown in FIG. 2).
A rear folding plate 48 and a round bar-shaped front folding member 49 are provided. The left and right folding plates 47 move so as to approach each other from both left and right sides (perpendicular to the paper surface) of the tray-equipped product TM and fold the left and right side edges of the film F to the bottom side of the tray T. The rear folding plate 48 moves to the front Fo from the rear B of the tray-mounted product TM and folds the side edge of the rear B of the film F into the bottom surface of the tray T. The front folding member 49 is driven by the pusher 52 driven at a predetermined timing synchronized with the rear folding plate 48 to discharge the commodity TM with the tray.
The side edge of the front Fo of the film F is folded into the bottom side of the tray T. The left and right folding plates 47, the rear folding plate 48, and the pusher 52 are driven by a forward / reverse rotation motor (not shown) constituting the actuator 28 of each unit shown in FIG. 3, and an encoder (not shown) for controlling the number of rotations of the motor. , The operation timing and the movement stroke are controlled by the control means 20. Here, as shown in FIG. 3, the servo controller 22 of the control means 20
And torque limit changing means 25. In FIG. 2, the torque limiting means 24 determines the torque of the servo motor M1 for driving the elevator mechanism 30 in a torque limiting area provided from the point P1 near the packaging position P2 to the lifting stop point Ps or its vicinity. To the torque limit value or less. The wrapping position P2 refers to the position of the stretched film F. In the following, the fact that the product TM with a tray is at the wrapping position P2 means that the product TM with a tray TM corresponds to the stretched film F. , Which means that the table 38 is in this position. Similarly, when there is a commodity TM with a tray at the points P0 to Ps, it means that the table 38 on which the commodity TM with the tray is placed is present at each point. The above-mentioned torque limiting area is defined by a distance (-H1 mm) from the packaging position P2 to the point P1 and a distance (-H1 mm) from the packaging position P2 to the ascending stop point Ps or its vicinity with the packaging position P2 as the reference point 0. + H2 mm), so that -H1 to
Displayed as + H2. The torque limit value is displayed as a percentage of the maximum torque. Further, torque limit changing means 2
5 changes the torque limiting area and the torque limiting value of the torque limiting means 24 according to the combination of the plurality of products M and the tray T. As shown in an example of FIG. 4, the memory 26 stores a combination number (NO.), A torque limit area (-H1 to + H2) for each combination of a plurality of products M and trays T.
) And the torque limit value (%) are stored. FIG. 5 shows a torque curve of the servo motor M1 when the elevator mechanism 30 is raised. Here, the table 38 of the elevator mechanism 30 starts to move up and the point P1
(T1 time) until the non-torque region (N
TA), an area in which the torque is restricted from the point P1 to the rising stop point Ps or its vicinity (time t3) is called a torque limiting area (TLA). This point P1 is determined in consideration of the height of the commodity TM with tray. The torque limit value is a value that does not damage the tray T with the torque of the servo motor M1 with respect to the film F.
0 and the weight of the table T (the weight of the table and the weight of the product), the hardness of the tray T and the shape of the tray T (height,
The value is determined based on the properties of the film F and the length. In this example, the case where the height of the tray T is larger than the height of the product M and the film F presses the tray T is described, but the height of the product M is higher than the height of the tray T. If it is larger, the product M is pressed against the lower surface of the film F, and the torque limit value is a value that does not damage the product M. Further, the torque limiting region is also appropriately changed based on the timing at which the product M is pressed against the film F instead of the tray T. Further, the torque limit value is appropriately changed based on a measured weight from the weighing mechanism or a load change applied to the servomotor when the product is transferred to the elevator mechanism. Next, the operation of this apparatus will be described. First,
For example, the combination number NO. A predetermined number of products TM with trays are packaged in a predetermined number. As shown in FIG. 1 torque limit area TLA
Is (−10 to +30), and the torque limit value is 50%. First, when the commodity TM with the tray is received at the lifting standby position P0 from the transport conveyor 42 in FIG. 2, the table 38 of the elevator mechanism 30 starts to rise. FIG.
, The torque increases at the start, but decreases when the commodity TM with the tray approaches the stretched film F due to the brake control of the speed reduction means 23 of the servo controller 22. The maximum torque in the non-torque limited region NTA is, for example, 100%. Then, if the commodity TM with tray hits the stretched film F before reaching the point P2 beyond the point P1, the torque curve in the decreasing state starts to increase again. However, since the torque limiting region TLA is provided from the point P1, the torque value of the servo motor M1 is limited to 50% or less. Therefore, after the point P3, the torque value does not increase and is maintained at 50%. As a result, even if the commodity TM with a tray hits the film F and is further pushed up by the table 38, the torque value of the servomotor M1 does not exceed the hardness of the tray T, so that the tray T is not damaged. Thereby, the trouble of the tray T can be prevented and the troubleshooting time can be shortened, so that the operation efficiency of the packaging device can be improved. After that, in FIG.
The film M is packaged by the film folding mechanism 50 in a state where the torque is limited to or near the rising stop point Ps. Then, the seal mechanism 5 is pushed by the pusher 52.
1 and is heat-sealed and discharged from the discharge conveyor 62 to the front Fo. At this time, the elevator mechanism 3
A zero empty table 38 begins to descend. FIG. 6 shows a torque curve of the servomotor M1 when the elevator mechanism 30 descends. Elevator mechanism 3
In the non-torque area NTA, the area until the table 38 of 0 starts descending and reaches the point P4 (time t4), the point P
An area in which the torque from 4 to the push-up standby position P0 is limited is referred to as a torque limiting area TLA. This point P4
Corresponds to the falling trouble of the product TM with the tray, and the torque limit value is set to
Is set to a value that does not collapse. First, in the normal torque curve shown by the dashed line, the torque gradually increases as the table 38 descends, and when the table 38 approaches the push-up standby position (origin) of the table 38, the brake of the deceleration means 23 of the servo controller 22 is released. It is reduced by the control and stops at the push-up standby position P0. Then, the subsequent combination number NO. One product TM with a tray is sent to the table 38. Here, a point P5 between the table 38 and the frame 35
If the product TM with a tray is falling, the product TM with a tray will bite into the lower surface of the table 38, and the torque sharply increases from this point P5. However, since the torque limiting area TLA is provided from the point P4, the torque value of the servo motor M is limited to, for example, 50% or less. Therefore, after the point P6, the torque value does not increase and is maintained at 50%. As a result, even if the table 38 pushes down the tray-equipped product TM, the torque value of the servomotor M1 does not exceed the hardness of the tray T, so that the tray T is similarly not damaged. As a result, an alarm buzzer occurs because the table 38 does not return to the origin, but the tray T is not broken and the product M is not scattered as in the related art, and the operation is performed by removing the falling product TM with the tray. Since the operation can be restarted, the operation efficiency of the packaging device is improved. Further, the servomotor M1 may be stopped when it is determined that the home position return is delayed by the cycle timer. Alternatively, the servo motor M1 may be stopped after the encoder position of the servo motor M1 does not advance. Next, the dropped commodity TM with tray is removed, and the table 38 stops at the push-up standby position P0. Then, the same operation as described above is performed, and the subsequent combination number N
O. One tray-equipped product TM is film-wrapped. Thus, a predetermined number of combination numbers NO. One tray-equipped product TM is film-wrapped. Next, the combination number NO. For example, the combination number NO. A predetermined number of products TM with trays 2 are packaged in a film. In this case, the combination number NO. 2 is input. Then, the NO. 2 is called, and the torque limit changing means 25 sets the last combination number NO. 1 as NO. The torque limit area and the torque limit value are changed to 2. Then, the torque limiting means 24 determines the NO. The torque limitation is performed in the torque limitation region TLA (−30 to +55) of 2 and the torque limitation value of 30%. This operation state is shown by a two-dot chain line in FIG. In this torque-limited state, N
O. The product TM with tray 2 is packaged in a film. Also, at the time of lowering, the torque limit changing means 25 changes the torque limit to a predetermined torque limit area and torque limit value in the same manner as described above. After that, the table 38
At the next push-up standby position P0. No. 2 with tray TM is sent in and is similarly film-wrapped, and a predetermined number of combination numbers NO. Product T with 2 trays
M is film wrapped. As described above, a plurality of products M and trays T
The torque limiting area and the torque limiting value are changed in accordance with the combination of the above, and the tray T is not damaged during a series of film wrapping operations, and the operation interruption time based on the damage trouble is shortened. Is improved. In this embodiment, according to the combination of a plurality of products M and trays T, the torque limiting means 24 controls the torque limiting based on the combination number, the torque limiting area, and the torque limiting value stored in the memory 26. However, the combination number No. is stored in the memory 26. Alternatively, only the torque limit value may be stored, a detection sensor such as a photoelectric sensor may be provided at a predetermined position in the operation area of the elevator mechanism 30, and the torque may be limited in the torque limit area detected by the detection sensor. Further, it is needless to say that the present invention can be applied to a case where the product M is directly placed on the table 38 without using the tray T and packaged in a film.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing a packaging device according to an embodiment of the present invention. FIG. 2 is a schematic sectional view showing a main part of the packaging device. FIG. 3 is a configuration diagram showing control means of the packaging device. FIG. 4 is a diagram showing data stored for each combination of a product and a tray. FIG. 5 is a diagram showing a torque curve at the time of rising. FIG. 6 is a diagram showing a torque curve at the time of descent. [Description of Signs] 30 ... elevator mechanism, 42 ... conveying means, 46 ... transfer mechanism, 50 ... film folding mechanism, 62 ... discharging means, 24
... Torque limiting means, 25 ... Torque limit changing means, M ... Commodity, T ... Tray, TM ... Product with tray, M1 ... Servo motor.

Continuation of the front page (56) References JP-A-8-253205 (JP, A) JP-A-6-2982111 (JP, A) JP-A-2-45329 (JP, A) Japanese Utility Model Application No. 58-12106 (JP) , U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65B 11/00-11/58 B65B 57/00

Claims (1)

(57) [Claims] [Claim 1] Conveying means for conveying goods, an elevator mechanism for pushing up the conveyed goods by a driving force of a motor, located above the elevator mechanism, and transferring the film to a packaging position. A transfer mechanism that stretches and pushes the product up against the film stretched at the packaging position, and further folds the left, right, front and rear ends of the film covering the top of the pushed up product into the bottom of the product to wrap the film. A film folding mechanism; a discharge means for discharging a film-wrapped product; a motor of an elevator mechanism in a torque-limited region provided between a position where the product hits the stretched film and a lifting stop point or the vicinity thereof when the product rises. Torque limiting means for limiting the torque of the predetermined torque limit value or less,
A packaging device comprising: a torque limit changing unit that changes a torque limit area and a torque limit value of the torque limiting unit according to a type of a plurality of products.