JP2003276069A - Method for inspecting injection-molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection method which can inspect appearance of a small injection-molded product such as a wire seal precisely, efficiently, and inexpensively. <P>SOLUTION: While a product injection-molded by using a molding mold having a split structure is held in an intermediate mold 20, a part of a post- molding mold, after mold opening, the product is photographed by using a CCD camera 58, and the presence/absence of a defect is judged by image processing to judge the product. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molded product such as a wire seal for sealing and waterproofing a connecting portion between a wire and a terminal forming electric wiring of an automobile or the like, and a connector seal for sealing and waterproofing between connectors. The present invention relates to an inspection method for determining the quality by determining the presence or absence of defects.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a wire seal and a connector seal which are conventionally used for sealing electric wiring of an automobile. In the figure, 200 is a wire, 2
Reference numeral 02 is a terminal connected to the wire 200, and reference numeral 204 is a wire seal for sealing and waterproofing the connecting portion between the wire 200 and the terminal 202.

Reference numeral 206 denotes a connector housing, which is 20
8 is a retainer, and 210 is a connector housing 20.
6 is a connector seal for sealing the connection portion between the connector housing 6 and the other connector housing (not shown). The wire seal 204 and the connector seal 210 are conventionally made of rubber, and injection molding is used as a molding method thereof.

These wire seals 204, connector seals 210, etc. are visually inspected after injection molding for defects such as lack of thickness, excessive burrs, and other defects. There is a need.

As the inspection method, conventionally, (a) molded products (these are small items, and a large number of them are generally injection-molded at the same time in the same mold) are released from the mold, and then the operator Is a visual inspection method, and (b) or after demolded products are re-arranged using a parts feeder, etc., the automatic inspection device determines whether there is a defect in the external appearance of each product and judges whether it is good or bad. The method of doing was used.

[0006]

[Problems to be Solved by the Invention]
In the case of (a) manual visual inspection, the processing capacity is low and there is a problem that it requires a lot of manpower and man-hours for the inspection.In addition, some defects may be overlooked while visually inspecting a large amount of products. There is a risk that the inspection quality is unstable, and there is a problem that a large amount of cost is required for the inspection.

On the other hand, in the latter case of (b), a mechanism for aligning the individual products released from the mold with the parts feeder or the like is required, and the alignment mechanism or the parts feeder or the like is required. Therefore, there is a problem that the inspection is temporarily stopped when trouble occurs on the transportation path during the aligned transportation, and the processing capacity is also limited in the inspection using the alignment mechanism and the automatic inspection device. However, there is a problem in that a large amount of equipment is required to process a large amount of the product, and thus this method also requires a large cost.

In the latter case of (B), it is still good when the product is hard, but especially when the product is elastic, such as rubber product, it is likely to deform in shape. Therefore, when it is supplied by the parts feeder and aligned by using the alignment mechanism and positioned at the predetermined inspection position,
There is a problem that the position and the shape become unstable, and an erroneous determination is likely to occur when the visual inspection is performed by the automatic inspection device.

Therefore, in order to make an accurate determination, another mechanism for correctly positioning the product at the inspection position and stabilizing the shape is required, which further increases the cost. . Although the wire seal and the connector seal for waterproofing the electric wiring of the automobile have been described above as examples, the same problem occurs when inspecting various other injection molded products.

[0010]

The method for inspecting an injection-molded product according to the present invention has been devised to solve such a problem. According to the first aspect of the present invention, the product injection-molded by using the mold having the divided structure is held in a part of the mold after the mold is opened, and the product is used by the imaging device in that state. It is characterized in that the image is picked up, and whether or not there is a defect is determined by image processing to determine the quality.

According to a second aspect of the present invention, in the first aspect, the product is an elastic product having elasticity such as a rubber product.

According to a third aspect of the present invention, in any one of the first and second aspects, a part of the molding die holding the product can be moved separately from the other part.

According to a fourth aspect of the present invention, in the third aspect, a plurality of molding dies for holding the product are prepared, and the product held by a part of the molding die is inspected and the product is It is characterized in that molding of a product using a part of another mold which is not held is performed in parallel.

According to a fifth aspect, in any one of the third and fourth aspects, the molding die has a pair of outer and middle dies,
It is characterized in that the product is held in the medium size.

According to a sixth aspect of the present invention, in the fifth aspect, the middle die has a thin plate shape.

According to a seventh aspect of the present invention, in any one of the fifth and sixth aspects, the forming die has a structure in which the held product is exposed at each of a pair of dividing surfaces of the middle die. The held product is imaged by the imaging device on each of the divided surfaces to determine whether the product is good or bad.

According to an eighth aspect of the present invention, in any one of the fifth to seventh aspects, there is one injection gate for the molding material in the molding die for each of the products, and the injection gate is a pair of divided surfaces of the middle die. One of the above and the same side is provided, and the product is imaged by the imaging device on at least the opposite side surface, and the quality is judged.

[0018]

As described above, according to the present invention, the product is injection-molded by using the mold having the divided structure, and after the mold is opened, the product is held in a part of the mold as it is. In this state, the product is imaged by using an imaging device, and image processing is performed to determine the presence / absence of a defect to determine the quality.

According to the present invention, an injection-molded product can be automatically inspected, and the inspection ability is higher than that in the conventional case where an operator visually observes the appearance by hand to inspect it. It is possible to significantly increase the inspection cost, and it is possible to prevent the defect from being overlooked as in the case of manual visual observation, thereby improving the inspection quality.

According to the present invention, the molded product is not released from the molding die but is held in a part of the molding die and an image is picked up by an image pickup device for visual inspection. ,
The feature is that it is used as a positioning type or alignment type for positioning products.

Usually, the molding or manufacturing area of the product and the inspection area are set in different areas. After the product molded in the molding area is released from the molding die, the inspection is set in another area. It is common to move to an area and inspect there. However, in this case, when the inspection is performed by using the automatic inspection device, the products which are released from the molding die and are separated are aligned again in a predetermined arrangement by using the parts feeder, the alignment mechanism, the positioning mechanism, or the like, and then positioned. Is essential.

However, in the present invention, the molded product is not immediately released from the mold, and the appearance is inspected using the image pickup device while holding the molded product in a part of the mold. Appearance inspection can be performed without separately requiring a feeder, an alignment mechanism, a positioning mechanism, and the like, while accurately positioning and holding it in a predetermined arrangement and shape, thereby increasing the inspection cost. It is possible to reduce the inspection capacity, improve the inspection processing capacity, and further improve the inspection quality.

In this case, C is used as the image pickup device.
A CD camera can be preferably used. Further, the present invention is particularly effective when applied to a case where a plurality of products are simultaneously molded with a molding die and the plurality of products are inspected.

The present invention is also particularly effective when applied to an elastic product having elasticity such as a rubber product (claim 2). In the case of elastic products, even if they are aligned and positioned using a parts feeder, alignment mechanism, positioning mechanism, etc., there is a risk that the products will not be aligned correctly or smoothly due to elastic deformation of the products. Therefore, when a product made of such an elastic product is automatically and uniformly imaged by the imaging device and the quality is judged by the image processing, there is a possibility that the product may be erroneously judged.

In the present invention, however, the appearance of the product molded by the molding die is held by a part of the molding die as it is, and the appearance is inspected by using the image pickup device. It is possible to distinguish and inspect.

According to a third aspect of the present invention, a part of the molding die holding the product is separated from the other part so that it can be moved. In this case, the molding die is used to move the product in the molding area. After molding, the product can be inspected in the inspection area by bringing a part of the molding die holding the product without bringing the entire molding die from the molding area to the inspection area.

In this case, a plurality of molds for holding the product are prepared, and the product held by a part of the mold is inspected, while a part of the other mold is used. The molding of the product can be performed in parallel, and the production and inspection capability of the product can be enhanced (claim 4).

In this case, the molding die may be composed of a pair of outer die and middle die, and the middle die may hold the product (claim 5). Further, in this case, the middle die can be made into a thin plate shape (claim 6). In such a case, when moving a part of the mold holding the product (medium size) to the inspection area for inspection, the weight of the object to be handled (medium size part of the mold) is light. Therefore, there is an advantage that handling including carrying is easy. The thin plate shape referred to here is 20 mm or less, and preferably 5 mm or more in consideration of strength.

According to a seventh aspect of the present invention, the held product is exposed on each of the pair of middle-sized split surfaces, and the image is picked up by the image pickup device on each of the pair of split surfaces to determine whether the product is good or bad. In such a case, it becomes possible to simultaneously judge and inspect excessive burrs and other defects in each of the two divided surfaces, that is, in two places.

According to an eighth aspect of the present invention, the injection gate of the molding material in the molding die is provided at one location for each molded product, and the injection gate is provided on either one and the same side of the pair of dividing surfaces of the middle die, and at least on the opposite side. In this aspect, the quality of the product is determined by imaging the product with the imaging device.

For example, when an injection gate is provided on each side of a pair of middle-sized dividing surfaces to inject the molding material, or when the injection gate is provided at an intermediate portion between the pair of dividing surfaces, a defect in the product is produced. There is a possibility that the places where meat is generated are not constant and vary, so that it becomes difficult to accurately identify and inspect defects due to lack of meat.

On the other hand, according to the eighth aspect, when a deficiency occurs, the deficiency appears on the side of the dividing surface opposite to the injection gate, so that the imaging is performed on the side of the dividing surface opposite to the injection gate. By imaging the product with the device and discriminating the defect, the defect due to the lack of thickness can be discriminated efficiently and accurately.

[0033]

EXAMPLE An example in which the present invention is applied to inspection of a wire seal as an injection molded product used for waterproofing electric wiring of an automobile will be described below in detail with reference to the drawings. In FIG. 1B, 10 is a wire seal, which is made of rubber and has a cylindrical shape as a whole. The wire seal 10 has a large-diameter portion 12 and a small-diameter portion 14, a plurality of annular convex portions 16 for sealing are provided at a plurality of axial positions on the inner peripheral surface, and an outer peripheral surface is provided. Annular bulge 17
Are provided at positions separated in the axial direction. The wire seal 10 is a small article having a total axial length of less than 8 mm.

In FIG. 1 (A), reference numeral 18 is a mold device, 20 is a middle mold in a molding mold 22, and 24, 26.
Are upper and lower molds as outer molds, respectively. Here, the middle mold 20 has a thin plate shape. 28 is a mounting plate, 3
0 and 32 are heat insulating plates, 34 is a piston, and 36 and 38
Are the corresponding plates. Further, 40 is a hanging pin, and a stopper 42 is provided at the lower end portion in the figure.

FIG. 1C shows a molding cavity for molding the wire seal 10 and its peripheral portion. In the figure, reference numeral 44 denotes a molding cavity having a concave shape corresponding to the wire seal 10. This molding cavity 44
Has a molding part 44 a formed on the middle mold 20, a molding part 44 c formed on the upper mold 24, and a molding part 44 b formed on the lower mold 26. Reference numeral 46 denotes a molding pin at the center for molding the hollow portion of the wire seal 10, which protrudes upward from the lower mold 26 in the drawing.

As described above, in this example, the molding cavity 4
Most of 4 is formed in the middle die 20, and a portion of the wire seal 10 that slightly forms the axial end face is formed in the upper die 2.
4 and the lower mold 26. In the figure, reference numeral 48a denotes a dividing surface of the middle die 20 with the upper die 24, and 48b
Is a dividing surface with the lower mold 26. Further, 50 is a molding material (rubber material) injection gate, and 52 is a runner portion.
Further, in FIG. 1A, reference numeral 54 is an injection port for the molding material.

FIG. 2 shows a plan configuration of the middle die 20 together with a vertical cross section of the main part. In this example, the mold 22 has a very large number (1020 in total in this example) of molding cavities 44, and as shown in FIG. The formed portion 44 a is formed on the middle die 20. Here, the molding portions 44a are arranged in a circular shape as a whole, but the respective molding portions 44a are
2 are arranged so as to form a straight line in the vertical direction in FIG.

To mold the wire seal 10 of this example,
Upper mold 2 in the mold open state as shown in FIG.
4, the middle mold 20 and the lower mold 26 are closed as shown in (II), and in that state, the rubber material is injected from the injection port 54 by the injection device as shown in (III), and the runner portion 52 , Molding cavity 44 through injection gate 50
The wire seal 10 having elasticity is vulcanized and molded by injecting and filling the inside, and maintaining it under pressure and heating for a predetermined time.

After vulcanization and molding for a predetermined time, the upper mold 24, the middle mold 20, and the lower mold 26 are separated from each other in the vertical direction in FIG. As shown in FIG. 4B, 10 remains in the middle die 20, and all the wire seals 10 are held by the middle die 20.

FIG. 4A shows an inspection method of this example for inspecting the appearance of the many wire seals 10 held in the middle die 20 in this way. As shown in the figure, in this example, after molding a large number of wire seals 10 by using the molding die 22 in the molding area, the wire seals 10 as the respective products are not released from the mold after the molds are opened, and The robot hand 5 is held in 20 as it is.
Move to the inspection area by 6.

In the inspection area, CC as an imaging device
The D cameras 58 are installed to face each other. In this example, the medium die 20 held by the robot hand 56 is passed across the imaging space of the CCD cameras 58, and in the process, one wire seal 10 held by the pair of CCD cameras 58 is held by the medium die 20. The images are picked up one by one, and compared with the image pickup result of a non-defective product which is stored in advance by image processing, and defects such as lack of wall and excessive occurrence of burrs in the wire seal 10 are discriminated to judge pass / fail.

Here, the pair of CCD cameras 58 are the medium type 2
Visual inspection is performed by imaging both surfaces of the wire seal 10 held at 0 in the axial direction. Then, when it is determined that the defective products are defective, the result is stored together with the addresses corresponding to the positions of the wire seals 10, and the defective products are automatically selected and discharged in the subsequent process.

Here, since each wire seal 10 is vertically held in a straight line on the middle die 20, the robot hand 56 linearly moves the middle die 20 up and down at a position between the pair of CCD cameras 58 and 58. 4 and then, the middle mold 20 is moved forward by one pitch of the molding cavity 44, and then moved again in the vertical direction. Thereafter, while repeating the same movement, the middle mold 20 is moved from the right direction to the left direction in FIG. Move to.

However, since the molding cavity 44 has a linear shape in an oblique direction, the middle mold 20 may be moved obliquely in some cases, and the middle mold 20 may be moved forward in a direction perpendicular to this, so that Molding cavity 4
4. Strictly speaking, the wire seal 1 held by the molding portion 44a
A visual inspection of 0 may be performed.

Incidentally, in FIG. 4, the CCD camera 58 on the right side of the drawing faces the dividing surface 48a of the middle-sized die 20, and the one CCD camera 58 faces the other dividing surface 48b, so that one CCD camera. 58 is a defect mainly due to excessive burrs existing on the split surface 48a of the wire seal 10, and the other CCD camera 58 is
A visual inspection is performed for defects of the wire seal 10 on the split surface 48b side and defects due to excessive burrs on the split surface 48b.

In this example, a plurality of middle dies 20 are prepared for each set of the molding dies 22, and the middle dies 20 holding the wire seals 10 are taken out from the molding area and carried to the inspection area after molding. , While the wire seal 10 is being inspected there
0 is combined with the upper mold 24 and the lower mold 26, and the injection molding of the wire seal 10 using the molding die 22 is performed in parallel in the molding area while the molded wire seal 10 is inspected. .

As described above, in this example, after molding the wire seal 10, the wire seal 10 is retained in the middle mold 20 as it is without being released from the mold, and the wire seal 10 is CC-bonded in that state.
The D camera 58 picks up an image and performs image processing to determine the presence / absence of defects, mainly the presence or absence of burrs and the presence / absence of flesh, to determine the quality. According to the method of this example, the injection-molded wire seal 10 can be automatically inspected, and the inspection ability is higher than that in the case where an operator visually inspects the appearance by hand and inspects it as in the conventional case. The cost can be significantly increased and the cost for inspection can be reduced. Further, it is possible to prevent a defect from being overlooked as in the case of manual visual observation, and it is possible to improve inspection quality.

The inspection method of this example is characterized in that the middle die 20 is used as a positioning die or an alignment die for positioning the wire seal 10. In the case of this inspection method, the die is released from the molding die. There is no need to align and position the disjointed wire seals 10 again in a predetermined arrangement by using a parts feeder, an aligning mechanism, a positioning mechanism or the like, so that the cost for the parts feeder, the aligning mechanism or the like can be reduced. You can

Further, although the wire seal 10 of this embodiment is a rubber elastic product having elasticity, the CCD camera 58
In the case of imaging and inspection by the above, the inspection can be performed in a strictly positioned state and in a state where it is held in a correct shape, and there is a possibility that the wire seal 10 is elastically deformed and is not correctly and smoothly aligned or is not positioned. Instead, the CCD camera 58 can automatically take a uniform image, and the quality can be accurately determined by image processing.

Further, in this example, a plurality of middle dies 20 are prepared, and after the molding, the middle dies 20 are moved to the inspection area, and while the wire seal 10 held by the middle dies 20 is inspected, another middle dies are also formed in the molding area. Molding using No. 20 can proceed simultaneously, and there is an advantage that molding capacity and inspection capacity are high.

Further, in this example, since the middle die 20, which is the holding die of the wire seal 10, is in the shape of a thin plate, when carrying out the inspection by moving it from the molding area to the inspection area, it is carried by the robot hand 56. It also has the point that handling is easy.

In this example, since the wire seal 10 is held by the middle die 20, the advantage that the appearance inspection by the CCD camera 58 can be performed from two directions opposite to each other as shown in FIG. In addition to having
An injection gate 50 for molding the wire seal 10 has a pair of split surfaces 48a, 4 in all of the wire seals 10.
8b on one side and the same side, specifically, on the side of the dividing surface 48a, and further, since the injection gate 50 is provided only at one location for each wire seal 10, the rubber material is not provided in the molding cavity 44. When the injection is insufficient, that is, when the wire seal 10 is lacking in thickness, the lacking portion is generated at the end on the side of the dividing surface 48b, and therefore the CCD.
There is an advantage that the defect due to the lack of thickness can be surely determined by observing only the divided surface 48b side with the camera 58 and the quality can be determined.

Although the embodiment of the present invention has been described in detail above, this is merely an example. For example, the above-mentioned embodiment is an example of the case of the inspection of the wire seal as the injection molded product, but the present invention can be applied to the inspection of the injection molded product of the connector seal and other types or applications in FIG. The present invention can be implemented with various modifications without departing from the spirit of the invention.

[Brief description of drawings]

FIG. 1 is a view showing a wire seal to be inspected according to the present invention together with its forming die and its periphery.

FIG. 2 is a diagram showing a plan configuration and a vertical cross-sectional configuration of a main part of the medium-sized die in FIG.

FIG. 3 is an explanatory view of a procedure of forming a wire seal using the forming die of FIG.

FIG. 4 is an explanatory diagram of an inspection method according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a use place of a wire seal.

[Explanation of symbols]

10 Wire seal 20 Medium 22 Mold 24 Upper mold 26 Lower mold 48a, 48b split surface 50 injection gates 58 CCD camera

Claims (8)

[Claims] 1. A product injection-molded using a mold having a split structure is held in a part of the mold after opening the mold, and the product is imaged by an imaging device in that state,
An inspection method for an injection-molded product, characterized by determining the presence or absence of defects by image processing and determining the quality. 2. The method for inspecting an injection-molded product according to claim 1, wherein the product is an elastic product having elasticity such as a rubber product. 3. The method for inspecting an injection-molded product according to claim 1, wherein a part of the mold holding the product is movable separately from the other part. 4. The method according to claim 3, wherein a plurality of molds for holding the product are prepared in advance, and the product held by a part of the mold is inspected and whether the product is not held. A method for inspecting an injection-molded product, characterized in that molding of a product using a part of the molding die is performed in parallel. 5. The injection molding according to claim 3, wherein the molding die has a pair of an outer die and a middle die, and the middle die holds the product. Product inspection method. 6. The method for inspecting an injection-molded product according to claim 5, wherein the middle die has a thin plate shape. 7. The molding die according to claim 5, wherein the molding die has a structure in which the held product is exposed on each of a pair of dividing surfaces of the middle die, and each of the pair of dividing surfaces. 2. A method for inspecting an injection-molded product, wherein the image of the held product is imaged by the imaging device to determine quality. 8. The injection gate for the molding material in the molding die according to claim 5, wherein one injection gate is provided for each product.
Injection molding, characterized in that the injection gate is provided on one side and the same side of the pair of middle-sized split surfaces, and the image is picked up by the image pickup device on at least the opposite side to determine whether the product is good or bad. Product inspection method.