JP2001293749A - Defective excluding apparatus for injection-molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defective excluding apparatus for an injection-molded article for measuring the weight of the molded article taken out of a mold to exclude a defective of which the weight is out of a standard value range from a belt conveyor to separate the same. SOLUTION: The defective excluding apparatus for the injection-molded article, which is equipped with a molded article automatic taking-out machine and a feed means, is equipped with the weight measuring instrument attached to the leading end of the molded article taking-out arm of the molded article automatic taking-out machine and holding the molded article to measure the weight of thereof, a controller for comparing the output signal from the weight measuring instrument with a set value and outputting a signal to an excluding means in order to exclude the molded article concerned from the feed means when the output signal from the weight measuring instrument is below the set value and/or exceeds the set value to issue a command of excluding operation and the excluding means for excluding the molded article on the feed means from the feed means on the basis of the input signal from the controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically taking out an injection molded product from a plastic injection molding machine and separating defective products. In the process of taking out, measure the weight of the molded article, judge whether the molded article is within the standard or out of the standard, place it on the transport means once, and if the weight of the molded article is out of the standard, remove it by the rejection means The present invention relates to a device for eliminating defective injection molded products, which eliminates the injection molded products from a conveying means.

[0002]

2. Description of the Related Art In general, in the case of plastic injection molding, an injection molded article is taken out by an automatic take-out machine installed on an injection molding machine, dropped on a belt conveyor, and then conveyed to a predetermined place by the belt conveyor. Packed and shipped after product inspection. At this time, the operation of the normally used automatic unloader is as follows.

[0003] When the resin in the mold of the injection molding machine is filled and the mold is opened, the molded product take-out arm of the automatic take-out machine is lowered by the telescopic drive mechanism to move the core and the fixed die plate attached to the movable die plate. Inserted between mounted cavities. Next, the molded product holding mechanism attached to the tip of the molded product take-out arm is moved to the core side by the horizontal traveling cylinder, and the molded product holding mechanism holds the molded product. Then, the molded product take-out arm retreats to the cavity side and then rises and is taken out above the mold. Next, the front and rear frames on the slide base are
The molded product moved in either the front or rear direction of the injection molding machine and held by a molded product take-out arm equipped with a horizontal traveling cylinder and a molded product holding mechanism attached to the tip of the arm is an injection molding machine. Move out. Further, the cylinder for controlling the attitude of the molded article attached to the molded article holding mechanism is operated, and the molded article holding mechanism is rotated 90 ° and turned downward, and then the molded article taking-out arm is lowered, and the injection molded article is placed on the belt conveyor. release. After that, the molded product take-out arm and the like stand by on the injection molding machine to end a series of operations. Due to its structure, the normally used automatic unloader can only remove the molded product in one direction, either in front of or behind the injection molding machine.

[0004] Among the molded products thus taken out, an injection molded product having an unfilled portion (short shot) is found as a defective product, and a product inspection for separating the product is conventionally performed.
It is performed by the following method. a. A method in which an operator visually separates each molded product into a regular product and a defective product. b. A special weight checker for measuring the weight of the injection molded product taken out by the automatic unloader is installed on the side of the injection molding machine or on the belt conveyor, etc., and the product weight is automatically measured and the standard value of the weight is measured. A method of setting and sorting by the discharge device provided in the weight checker. c. A weight measuring device is installed on the molded product take-out arm of the automatic unloader that divides the molded product take-out arm itself to the left and right. The weight of the injection-molded product is measured, and compared with the preset standard value of weight, it is determined that the product is good or bad. A method that sorts the non-defective product by separating the molded product take-out arm itself to the left and right. For example, in Japanese Patent Application Laid-Open No. 8-258093, a weight measuring device is attached to a molded product take-out arm, and when the molded product is taken out from a mold, the weight of the molded product is measured. Alternatively, a control device compares the weight with the non-standard weight, and based on the result of this determination, moves the molded product take-out arm back and forth. Have been.

[0005]

However, the above-mentioned conventional method has the following disadvantages. a. A method in which an operator visually separates each molded article requires a dedicated worker, and in addition, a defective product may be overlooked, or the separated molded article may be sorted by the worker to each sorting place. Carrying process is required. b. The method of automatically sorting with a dedicated weight checker is generally used to transfer weight checkers and molded products to the weight checker when introducing this method to existing equipment to automate the rejection of defective products. It is necessary to change a new installation place and a layout for equipment to be newly installed, such as a transfer device, and often requires not only the equipment cost but also the cost for changing the layout. c. The method of distributing the front and rear frames of the automatic unloader to the left and right by separating the front and rear frames of the automatic unloader by setting the weight measuring device on the molded product take-out arm of the automatic unloader that sorts the left and right frames to automate the rejection of defective products When this method is introduced into existing equipment, it cannot be handled by a normal automatic unloader that is already in use, and it is necessary to newly install a dedicated automatic unloader, and the equipment cost becomes enormous. And the like.

[0006] Therefore, there has been a demand for the development of an apparatus for separating defective injection-molded products at low cost and with high reliability without requiring any manual operation.

[0007]

Means for Solving the Problems The inventor of the present invention has made intensive studies to solve the above-mentioned problems, and attached a weight measuring device to the tip of a molded article take-out arm of an existing automatic molded article unloading machine. The weight of the injection molded product is automatically measured while holding the molded product at the tip of the molded product take-out arm, and the molded product is placed on the transporting means. It has been found that by separating non-defective products, defective products of injection molded products can be separated at low cost and with high reliability without requiring human labor.

That is, the present invention relates to an automatic injection molding machine for taking out a molded product from an injection molding machine, and an injection molded product equipped with a conveying means for conveying the molded product taken out by the automatic plastic injection molded product removing machine. In the non-defective product removal device, a weight measuring device attached to the tip of the molded product take-out arm of the automatic plastic injection molded product unloader for measuring the weight of the molded product while holding the molded product, and a predetermined value are input in advance. Setting, comparing the output signal from the weighing device with the set value, and when the comparison shows that the output signal from the weighing device is less than the set value and / or exceeds the set value, the corresponding molded article And a controller for outputting a signal to the elimination means to instruct the elimination operation to eliminate the defective article from the transport means, and an input signal from the defective article elimination controller. A defective elimination device for an injection molded article, characterized in that it comprises a removing means for eliminating from the conveying means a molded article on the transport means.

The rejection device of the present invention has the following features. 1. A weight measuring device for measuring the weight of the molded product between the tip of the molded product take-out arm of the existing automatic unloading machine and the molded product holding mechanism, and defective injection from the transport means to the existing transport means body etc. The rejection device according to the present invention is provided by attaching a rejection means for rejecting the molded product and a controller for rejecting the rejected product which determines whether the weight of the injection molded product is within the standard or not according to the output signal from the weighing device. Therefore, it is not necessary to introduce new expensive equipment or change the layout, and it is possible to easily and inexpensively sort defective injection molded products. 2. This eliminates the possibility of oversight of defective products, and allows more reliable separation of defective injection-molded products than the conventional method of visual inspection by workers. You also need less. 3. If the weight measurement data is imported to a personal computer, statistical processing can be performed and quality control of the molded product can be performed. 4. When discriminating a defective product, it can be set to exclude it as a defective product when the value exceeds a predetermined value, as well as when the value is less than a predetermined value. As in the case where a raw material mixture having a greatly different density such as is supplied to an injection molding machine and molded, the composition of a molded product fluctuates due to poor supply of each raw material at the time of mixing and segregation of the raw material mixture, and it becomes heavier than a predetermined weight. Even when a molded product that is lighter or lighter is obtained, the molded product can be separated as a defective product.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a defective product removing apparatus according to the present invention, an automatic unloading machine is a commonly used automatic unloading machine in which the direction of opening a molded product after unloading is fixed in one direction. As an example of an automatic unloader, a front and rear frame provided with a molded product take-out arm that moves in the longitudinal direction of the injection molding machine, and a slide base that moves the front and rear frames in one of front and rear directions of the injection molding machine. Is provided.

The conveying means for conveying the molded product taken out by the automatic take-out machine to the next step is not particularly limited, and a commonly used belt conveyor can be used without any trouble.

Usually, a molded product holding mechanism is directly attached to the tip of the molded product take-out arm of the automatic unloader.
In the defective product removing device of the present invention, a weight measuring device is attached between the molded product take-out arm and the molded product holding mechanism. The attached weight measuring device uses a load converter, a so-called load cell, and it is preferable to use two or more attached weight measuring devices. The weighing device is attached with bolts or the like, whereby the weight of the molded article can be measured while holding the molded article. The weight of the molded article measured by the weighing device is output as an electric signal.

The controller for eliminating defective products can set a predetermined weight value in advance, compares the output signal based on the weight measurement of the weight measuring device with the set value, and determines that the output signal from the weight measuring device is less than the set value. When or exceeds the set value, a signal for instructing the elimination means to operate to output the molded article to be eliminated from the conveying means is output. Since the output signal from the weighing device changes due to the vibration of the injection molding machine or automatic unloader during the measurement, the output signal from the weighing device is sampled at certain intervals, and the average weight during the measurement time is calculated. It is preferable to calculate and compare the average weight with a set value. If the lower limit weight and the upper limit weight are set as the set values, in addition to the case where the weight of the molded product is less than the lower limit weight due to a short shot or the like, a mixture of raw materials having different densities is used, and the molded product is segregated by the raw material. In the case where the composition shifts and exceeds the upper limit weight, the molded product can be excluded as a defective product, so that finer quality control can be performed, which is preferable. In addition, it is possible to further classify non-defective products by increasing the set number.

In the case where the molded product taken out by the automatic take-out machine and released on the conveying means is immediately removed from the conveying means at the conveyance start position, the molded article is removed based on the signal output from the defective product elimination controller. A signal for instructing the removing means to operate may be output immediately or simultaneously with the input of the molded article release signal of the automatic unloader. Also, in order to ensure rejection, after the molded product release signal of the automatic unloader is input, the timer must be delayed by the timer until the molded product falls on the conveyance means, or the molded product will drop to the reject position. It is preferable to output a signal for instructing the exclusion unit to operate after confirming that the operation has been performed with a photoelectric tube or the like. When excluding a molded product at a position distant from the transfer start position, the timing is set so that a signal for instructing the rejection unit to operate from the defective product rejection controller is delayed by a timer or the like by the time of transport to the rejection position. do it.

The rejecting means for rejecting the rejected molded product from the conveying means is preferably one which can be attached to the conveying means main body. The piston is driven in a reciprocating manner by a piston in a direction intersecting the conveying direction. A plate having a plate, a plate having a guide plate called a flipper gate, which guides and removes a molded product to the side of the conveying means when the conveying path is closed can be used without any trouble.

Next, the operation of the rejection apparatus according to the present invention will be described below.

First, when the mold of the injection molding machine is filled with the resin and the mold is opened, the molded product take-out arm of the automatic take-out machine which has been waiting at the standby position above the mold is moved by the telescopic drive mechanism. Between the core and the cavity. At this time, the molded product holding mechanism attached to the tip of the molded product take-out arm via a weight measuring device is oriented in a direction (sideways) in which the molded product posture can be held by the molded product posture control cylinder. Next, the molded product take-out arm is moved to the core side by the horizontal traveling cylinder, and the molded product holding mechanism holds the molded product. Subsequently, the molded product take-out arm returns to the cavity side to the raised position, and rises to take out the molded product above the mold. Then, after the front and rear frames on the slide base are moved by the front and rear frame drive motor onto the conveying means arranged before or after the injection molding machine, the cylinder for controlling the posture of the molded product is actuated and the molded product is moved. The molded article holding mechanism attached to the tip of the take-out arm via a weight measuring device rotates 90 ° and faces downward.

Next, the molded article take-out arm descends and stops just above the conveying path of the conveying means, the molded article is released from the molded article holding mechanism, and falls on the conveying path. The weight of the molded product is
The measurement is performed until the molded product take-out arm stops immediately above the transport path of the transport means and opens the molded product. After this,
The cylinder for controlling the posture of the molded product is actuated again, and the molded product holding mechanism attached to the tip of the molded product take-out arm via the weighing device is rotated by 90 ° so that it is again turned sideways, and the molded product is removed by the automatic unloader. The arm returns to the standby position above the mold and prepares for the next removal. The above-described series of operations of the automatic unloader is a general operation of a commonly used automatic unloader.

The weight of the molded product is the molded product-the molded product holding mechanism-
When the weighing devices are arranged vertically (when the molded product holding mechanism is downward), the front weight of the molded product is applied to the weighing device so that accurate measurement can be performed. Therefore, as described above, besides immediately before releasing the molded article to the transport path,
After the molded product take-out arm moves to the conveyor means such as a belt conveyor, the molded product holding mechanism attached to the tip of the molded product take-out arm via the weighing device faces downward, or at the tip of the molded product take-out arm. If the molded product is held by the molded product holding mechanism attached via the weighing device and it is taken out above the mold and turned downward, the weight of the molded product is measured any time thereafter until the molded product is opened be able to. In addition, since the direction of inertia due to the operation immediately before the weight measurement is vertical, more accurate weight measurement can be performed. Therefore, the weight measurement is performed before the molded product take-out arm descends just above the conveyance means and releases the molded product. Is preferred.

The weight data measured by the weight measuring device is immediately averaged by the controller for eliminating defective products, and is compared with upper and lower limits of a predetermined weight. If the average weight deviates from the upper and lower limit values, a signal for driving the elimination means is output to the elimination means at a preset timing, and the elimination means removes and sorts the defective molded article from the conveying means.

[0021]

According to the present invention, there is provided: Weight measuring device, controller for rejection of defective products and rejection means,
It can be configured simply by attaching it to the existing automatic unloader and transport means, and a new weight checker and a special weight checker that requires the introduction of a new transport device or modification of the transport device, and the automatic unloader itself The cost required for introduction is lower than that of an arm-distribution type automatic unloader that needs to be performed. 2. Compared to the conventional method of visual inspection by a dedicated worker or inspection by a scale, defective products are not overlooked and labor costs are reduced. 3. If the weight measurement data is imported to a personal computer, statistical processing can be performed and quality control of the molded product can be performed. 4. When determining a defective product, if it exceeds a predetermined set value, it can be set to exclude it as a defective product, so injection molding of a raw material mixture with a greatly different density such as a mixture of a master batch of resin with high filler and resin pellets Even if the mixing ratio shifts due to the segregation of raw materials such as feeding to a molding machine and there is a possibility that a molded product with a varied composition may be obtained, the weight of the molded product is measured and classified as defective. It becomes possible.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic plan view of a defective product removing apparatus according to the present invention. An automatic molded product unloading machine 2 is attached to an upper part of the injection molding machine 1. On the rear side of the injection molding machine, a belt conveyor 13 is provided as a means for conveying a molded product, and an elimination means 20 is attached to the belt conveyor 13. The molded product A after the injection molding is taken out of the mold of the injection molding machine 1 by the molded product automatic take-out machine 2, opened on the belt conveyor 13, and conveyed to the next step.

FIG. 2 is a side view of the automatic unloader to which the weight measuring device is attached. Fixed die plate 10 for injection molding machine
1 is provided with a molded article automatic take-out machine 2. A slide base 3 for sliding the front and rear frames 4 in a direction orthogonal to the longitudinal direction of the injection molding machine 1 is installed above the automatic unloading machine 2.
Thus, the front and rear frames 4 are configured to be able to slide and move between the injection molding machine 1 and a belt conveyor 13 provided on the rear side of the injection molding machine.

An extensible drive mechanism 7 for extending and retracting the molded product take-out arm 9 in the vertical direction and a horizontal traveling cylinder 6 for moving the molded product take-out arm 9 in the horizontal direction along the front and rear frames 4 are provided on the front and rear frames 4. Have been.
A molded article holding mechanism 12 is provided at the lower end of the molded article take-out arm 9.
And a molded article attitude control cylinder 10 are provided.
A weight measuring device 11 is mounted between the molded product holding mechanism 12 and the molded product take-out arm 9. A load cell is used as a weight measuring device. Mold holding mechanism 12
The posture of the is controlled downward and sideways by the molded article posture control cylinder 10.

FIG. 3 is a side view of a belt conveyor for conveying the injection-molded article, and FIG. 4 is a view of FIG. 3 as viewed from the left, and shows an injection-molded article A taken out of the injection molding machine. Are shown on the belt conveyor.

The belt 17 installed on the belt conveyor 13 is moved continuously or intermittently by the belt drive motor 14, the belt rotating rolls 15, 16 and the belt drive controller 18 (in FIG. The upper surface moves rightward) and conveys the molded article to a predetermined place. The belt conveyor 13 includes a piston 21 and an extruding plate 22 as exclusion means 20 for eliminating defective products.
Are mounted by a mounting plate 23, and the pushing plate 22 is reciprocally movable in a direction perpendicular to the running direction of the belt 17. Further, a controller 19 for rejecting defective products for measuring the weight of the injection molded product A to determine whether or not the product is defective, operating the piston 21 and removing the defective product from the belt conveyor 13 is attached. .

The electric signal of the weight of the molded article measured by the weight measuring device 11 is sampled at regular intervals within a constant measuring time by a defective product rejection controller 19, and is averaged. Then, the weight is compared with the preset lower limit weight and upper limit weight, and if it is out of these, an operation signal is sent to the piston 21.

Next, the operation of the rejection apparatus according to the embodiment will be described below.

When the mold of the injection molding machine 1 is filled with the resin and the mold is opened, the molded product take-out arm 9 of the automatic unloader, which has been waiting at the standby position above the mold, is lowered by the telescopic drive mechanism 7. Is inserted between the core and the cavity of the injection molding machine 1. The molded product holding mechanism 12 attached to the tip of the molded product take-out arm 9 via the weight measuring device 11 is oriented sideways by the molded product attitude control cylinder 10. Next, the molded product take-out arm 9 is moved to the core side by the horizontal traveling cylinder 6, and the molded product holding mechanism 12 holds the molded product. Subsequently, after the molded product take-out arm 9 returns to the cavity side to the raised position, the molded product take-out arm 9 is raised to take out the molded product above the mold. And slide base 3
The front and rear frame 4 on the top is the front and rear frame drive motor 5
After being moved onto the belt conveyor 13 arranged on the rear side of the injection molding machine 1, the weight measuring device 1
1. The molded product holding mechanism 12 attached via 1 is 90 °
Rotate downwards.

FIG. 5 shows that the molded article holding mechanism 12 is rotated 90 ° by the molded article attitude control cylinder 10 and the injection molded article A is rotated.
It is a side view which holds downward.

Next, the molded product take-out arm 9 is lowered by the telescopic drive mechanism 7 to just above the belt 17 of the belt conveyor 13 and stopped. The molded article A is released on the belt 17 after being held for a predetermined time by a timer of the automatic unloader.

The weight measurement of the injection molded product is performed while the injection molded product A is held directly above the belt 17. Upon receiving the signal to start lowering the molded article take-out arm 9 from the automatic unloading machine 2, the controller 19 for removing defective products, after a lapse of a predetermined time (time until the descent of the molded article take-out arm 9 is completed), causes the molded article A to return. Start the weight measurement of. The signal output from the weighing device 11 is sampled at certain intervals, an average weight within a measurement time is calculated, and this is compared with a preset upper limit weight and lower limit weight. When the average weight value deviates from the upper and lower limit weights, upon receiving a molded product release signal from the automatic unloader, the delay timer waits until the molded product A falls on the belt 17, and then the piston 21 receives the piston operation signal. The molded product A sent and dropped on the belt 17 is removed and separated by the extruding plate 22.

After releasing the molded product A, the molded product take-out arm 9 of the automatic unloading machine rises and stops, and the molded product holding mechanism 12 attached to the tip end of the molded product take-out arm 9.
Is rotated by 90 ° by the molded article attitude control cylinder 10 to be turned sideways again, and then returned to the standby position above the mold to prepare for the next removal of the molded article.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a defective product removing device according to the present invention.

FIG. 2 is a side view of a molded product automatic unloader equipped with a weight measuring device.

FIG. 3 is a side view of a belt conveyor provided with a removing unit.

FIG. 4 is a configuration diagram of a belt conveyor when FIG. 3 is viewed from the left.

FIG. 5 is a side view of a molded product take-out arm when measuring the weight of an injection molded product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection molding machine 101 Fixed die plate 102 Movable die plate 2 Automatic removal machine 3 Slide base 4 Front and rear frame 5 Front and rear frame drive motor 6 Horizontal traveling cylinder 7 Telescopic drive mechanism 8 Runner take-out arm 9 Mold take-out arm 10 Mold posture Control cylinder 11 Weight measuring device 12 Mold holding mechanism 13 Belt conveyor 14 Belt conveyor drive motor 15 Belt rotation roll 16 Belt rotation roll 17 Belt 18 Belt conveyor drive controller 19 Defective product elimination controller 20 Elimination means 21 Piston 22 Extrusion Plate 23 Piston mounting plate A Injection molded product

Claims (1)

[Claims] 1. An apparatus for automatically removing a molded product from an injection molding machine, comprising: a plastic injection molded product automatic take-out machine; and a conveying means for conveying the molded product taken out by the plastic injection molded product automatic take-out device. In the plastic injection molded product automatic take-out machine attached to the tip of the molded product take-out arm, a weight measuring device for measuring the weight of the molded product while holding the molded product, a predetermined value can be input and set in advance, The output signal from the weighing device is compared with the set value, and when the output signal from the weighing device is less than the set value and / or exceeds the set value, the corresponding molded article is conveyed. A rejection controller for outputting a signal to the rejection unit and instructing a rejection operation to eliminate the rejection from the means; A rejection device for rejecting a molded product from the conveying means;