JP2008188615A - Method and apparatus for inspecting under-fill of forging - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for easily and accurately performing an inspection for determination of the presence of an under-fill in a product part, with simple constitution, such as determination whether the under-fill occurs or not in the product part, or the determination whether the extent of the under-fill is in the allowable limiting range or not when the under-fill occurs. <P>SOLUTION: The method for inspecting under-fill of a forging is provided for determining the presence of the under-fill in the product part P of the forging F including the product part P and a burr part B, wherein the forging F is formed by subjecting a blank f to die-forging with the use of forging dies 1, 2 and the product part P is obtained by removing the burr part B from the product part P of the forged product F. The method is characterized in that weight Pw of the product part P is obtained and also a correction weight of the product part P caused by the opening variation in the forging die 1, 2 at the forming time of the forged product F, is obtained, then a corrected weight Pcor of the product part P is calculated by subtracting the correction weight of the product part P from the weight Pw of the product part P, and the under-fill of the product part P is determined based on the corrected weight Pcor of the product part P. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a forging inspection method and a lack inspection device, and in particular, a forging product including a product portion and a burr is formed by die forging a material with a forging die, and the product portion of the forging product. Inspection method for removing burrs and determining the lack of product parts, and forgings formed by forging the material with a forging die, judging the lack of product parts from which burrs have been removed It is related with the inspection apparatus for doing.

  For example, a crankshaft of an engine such as an automobile is formed by forging a material with a forging die to form a forged product in which a product part and a burr are formed, and removing the burr from the product part of the forged product. Accordingly, the product is manufactured by allowing it to cool or performing predetermined machining such as shot blasting.

  When forming a forged product, the temperature distribution of the forging die and material will be biased, the material will not fill the forging die impression due to the fluidity of the material and the lubrication conditions of the impression surface of the forging die, etc. Meat may be produced. When the lacking thickness is small, a product formed into a desired shape can be obtained by subsequent machining or the like. However, when the lacking thickness is large, a product having the desired shape can be obtained even if a subsequent machine is applied. Since it cannot be obtained, a forged product in which such a large cutout has occurred is regarded as a defective product. Patent Document 1 is known as a technique for automatically and accurately determining whether a target forged product is non-defective or defective.

  In Patent Document 1, in a forging machine in which a lower die and an upper die are installed on a forging shaft core so as to be opposed to each other and relatively movable, the lower die and the lower die are received. A lower forging force receiving member including an intermediate member provided in a force transmission path through which forging force is transmitted; and a force transmission path through which the forging force received by the upper mold and the upper mold is transmitted. The upper forging force receiving member including the intermediate member and the lower forging force receiving member and / or the forging pressure from the target forging applied to the predetermined region of the upper forging force receiving member is deformed for each predetermined region. A deformation amount detecting means comprising a plurality of strain gauges attached to one or both of the lower forging force receiving member and the upper forging force receiving member, and the deformation amount detecting means The predetermined output Electricity which processes the detection amount for each zone in terms of electricity and measures the forging pressure applied from the target forging to the predetermined region of the lower forging force receiving member or the upper forging force receiving member for each predetermined region. And a forging state measuring device for a forging machine, which is characterized in that it is configured to have a mechanical measuring means. That is, in Patent Document 1, a forging pressure is detected as a deformation amount by analyzing signals output from a plurality of strain gauges, and a non-defective product or a defective product of a target forged product such as a lack of wall is determined. .

  In addition, the purpose is to produce a product that is continuously mass-produced by a forging die, for example, a connecting rod for an engine, and in which it is necessary to prevent variation in weight as much as possible. As such a technique, Patent Document 2 is known. In Patent Document 2, a distance between molds and a weight of a molded product that are continuously stamped are measured, a difference in weight with respect to a predetermined weight of the molded product is calculated, and a stamping direction of the difference in weight is calculated. The difference in weight caused by the metal wear obtained by subtracting the difference in weight caused by the thickness variation of the mold is calculated, and a correction value for the distance between the molds corresponding to the difference in weight caused by the die wear is calculated. The weight of the molded product is calculated by calculating from the weight value per unit thickness in the die-cutting direction obtained in advance and adjusting the shut height by converting the correction value of the distance between the molds into the correction value of the shut height. A forging method characterized in that the above is made uniform is disclosed. That is, Patent Document 2 is for correcting a variation in weight due to wear of a mold.

  By the way, generally, when a lacking part is generated in the product portion, the weight is reduced according to the size of the lacking part. Therefore, by measuring the weight of the product part, it is considered that the inspection for determining the lack of the thickness such as the presence or absence of the lack of the thickness or the size of the lack of the thickness can be performed. .

Japanese Patent Laid-Open No. 7-016688 JP-A-4-66241

  However, in the above-mentioned Patent Document 1, since a deformation amount detecting means comprising a plurality of strain gauges is attached to one or both of the lower forging force receiving member and the upper forging force receiving member, forging equipment There is a problem that the cost of the forging equipment is increased and versatility is lowered. Further, in Patent Document 1, a deformation amount detecting means constituted by a strain gauge and an electrical measuring means for measuring a forging pressure by a detection amount output from the deformation amount detecting means are electrically connected. Wiring is necessary, and every time the forging die is changed to change the forging, the wiring work is complicated in a limited space in the forging facility, and disconnection is likely to occur. There were also problems such as low reliability.

  On the other hand, the above-mentioned Patent Document 2 is intended to produce a product in which the fluctuation of the weight due to wear of the forging die is reduced. This does not consider the change in the weight of the product due to the above, and the object of the present invention is different.

  Further, when the material is forged with a forging die, the opening amount of the forging die may vary due to various factors. As shown in FIG. 4, when the opening amount of the forging dies 1 and 2 is changed, the thickness Pt of the product part P and the thickness Bt of the burr are changed, and accordingly the thickness Pt of the product part P is changed. Therefore, the weight Pw of the product part P also fluctuates. Therefore, in the case of performing the inspection for determining the lack of thickness by measuring the weight Pw of the product part P among the above conventional techniques, simply measuring the weight Pw of the product part P is not enough. There is a problem that the determination of the lack of the product part P cannot be accurately performed.

  The present invention has been made in view of the above-described problems. With a simple configuration, it is possible to determine whether or not a product portion has a lack of thickness, and to accept the extent of the lack of a lack of thickness. It is an object of the present invention to provide a method and apparatus capable of easily and accurately performing an inspection for determining a lack of a product part, such as determination of whether or not it is within a possible limit range.

  In order to solve the above-mentioned problems, the invention relating to the forging inspection method for forgings according to the present invention forms a forging including a product part and burrs by die forging a material with a forging die, and the forging This is an inspection method for removing burrs from product parts and determining the lack of product parts. The weight of the product part is obtained, and the correction of the product part due to variation in the forging die opening at the time of forming the forged product. The weight is obtained, the weight of the product part is corrected by subtracting the corrected weight of the product part from the weight of the product part, and the lack of the product part is determined based on the corrected weight of the product part. .

  Further, in order to solve the above problems, the invention relating to the forging inspection apparatus according to the present invention is a product part in which a burr is removed from a forging formed by forging a material with a forging die. An inspection apparatus for determining a lack of thickness, a weight measuring means for measuring at least one weight of a material, a product part and a burr, a thickness measuring means for measuring at least one thickness of the product part and a burr, Obtain the weight of the product part, find the corrected weight of the product part due to the forging die opening fluctuation at the time of forming the forged product, and subtract the corrected part weight of the product part from the weight of the product part to correct the weight of the product part And a missing portion determination means for determining a lack of product portion based on the corrected weight of the product portion.

  According to the invention relating to the forging inspection method for forgings according to the present invention, as the forging die opening fluctuates during molding of the forgings, the thickness of the forgings also varies from the set value, thereby removing burrs. The weight of the product part also fluctuates from the set value, but the weight of the product part is obtained, and the weight of the product part is obtained by correcting the weight of the product part due to the forging die opening fluctuation at the time of forming the forged product. By subtracting the corrected weight of the product part from the product part, the product part weight is corrected, and the product part lack is determined based on the corrected product part weight. And inspection methods that can easily and accurately determine the lack of a product part, such as the judgment of whether or not the lack of a part is within the allowable limits. Can be provided.

  Further, according to the invention relating to the forging inspection of a forged product according to the present invention, the thickness of the forged product also fluctuates from the set value as the opening of the forging die varies during the molding of the forged product. The weight of the product part from which the material has been removed also varies from the set value, but with a simple configuration comprising weight measuring means, thickness measuring means, and lacking thickness judging means, the weight measuring means allows the The weight of the product part is measured indirectly or directly by the difference, and from the thickness of the product part or burr measured by the thickness measuring means, the lack thickness judging means depends on the forging die opening fluctuation at the time of forming the forged product. Obtain the corrected weight of the product part, subtract the corrected weight of the product part from the weight of the product part, correct the weight of the product part, and determine the lack of the product part based on the corrected weight of the product part With a simple configuration, Determining the lack of product parts easily and accurately, such as determining the presence or absence of a lack of parts, or if the lack of a part is within the allowable limits. It is possible to provide an inspection apparatus capable of performing the above.

(Aspect of the Invention)
In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following terms, (1) corresponds to claim 1, (2) corresponds to claim 2, (3) corresponds to claim 3, and (4) claims. This corresponds to item 4.

(1) An inspection method for forming a forged product including a product part and a burr by forging the material with a forging die, removing the burr from the product part of the forged product, and determining a lack of a product part Because
In addition to obtaining the weight of the product part, obtain the corrected weight of the product part due to the forging die opening fluctuation at the time of forming the forged product,
Subtract the weight of the product part from the weight of the product part to correct the weight of the product part,
A method for inspecting a lack of a forged product, comprising: determining a lack of a product portion based on the corrected weight of the product portion.

  In the method for inspecting forging of a forged product in item (1), the thickness of the forged product also varies from the set value as the amount of opening (clearance) of the forging die varies when the forged product is formed. The weight of the product part that has been removed will also vary from the set value, but the weight of the product part is determined, and the corrected weight of the product part due to the forging die opening fluctuation at the time of forming the forged product is determined. The weight of the product part is corrected by subtracting the corrected weight of the product part from the weight of the product, and the lack of the product part is determined based on the corrected weight of the product part. In addition, it is possible to easily and accurately determine the lack of the product portion, such as determining whether the lack of the thickness is within an allowable limit range when the lack is present.

  (2) The correction weight of the product part is obtained by multiplying the difference between the measured value of the burr thickness or the product part thickness and the set value by the projected area of the product part and the material density. The forging inspection method for forged products according to item (1).

  In the method for inspecting forging of a forged product according to item (2), in the invention according to item (1), from the difference between the measured value of the thickness of the burr or the thickness of the product part and the set value, A variation error can be obtained from the set value of the thickness of the forging product as the opening of the forging die fluctuates. By multiplying this thickness variation error by the projected area of the product part and the material density, The corrected weight can be easily obtained.

  (3) According to the item (1) or (2), it is determined whether the lack of the product part is within the limit by comparing the corrected weight of the product part with a threshold value. Inspection method for missing forgings.

  In the forging inspection method for forgings in (3), in the invention described in (1) or (2), by comparing the corrected weight of the product part with a preset threshold value, It is possible to easily and objectively determine whether the lack of the product portion is within the limit.

(4) An inspection device for judging a lack of a product part from which a burr has been removed of a forged product formed by forging a material with a forging die,
A weight measuring means for measuring the weight of at least one of the material, the product part and the burr;
A thickness measuring means for measuring at least one thickness of the product portion and the burr;
Obtain the weight of the product part, find the corrected weight of the product part due to the forging die opening fluctuation at the time of forming the forged product, and subtract the corrected part weight of the product part from the weight of the product part to correct the weight of the product part And a lack determination unit for determining a lack of product part based on the corrected weight of the product part,
A forging missing thickness detecting device characterized by comprising:

  In the forging inspection device according to item (4), the under-evaluation means obtains the weight of the product portion based on the measurement result of the weight measurement means, and forms the forging product based on the measurement result of the thickness measurement means. The corrected weight of the product part due to the fluctuation of the forging die opening or the thickness of the forged product at the time is obtained, and the weight of the product part is corrected by subtracting the corrected weight of the product part from the weight of the product part. The lack of the product part can be determined based on the weight of the product part. Therefore, the lack of the product part can be easily and accurately inspected.

One embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5 in the case of manufacturing a crankshaft of an engine such as an automobile as a final product of a forged product F. In addition, the same code | symbol shall show the part which is the same or it corresponds.
The apparatus for inspecting forging of forged product F according to the present invention is generally used for forging product F formed by forging material f with forging dies 1 and 2, and for lacking in product portion P from which burrs B have been removed. A weight measuring means (to be described later) for measuring at least one weight fw, Pw, and Bw of the material f, the product part P, and the burr B, and at least one thickness Pt of the product part P and the burr B for determination. A thickness measuring means (described later) for measuring Bt, a weight Pw of the product part P, and a corrected weight of the product part P due to fluctuations in the opening of the forging dies 1 and 2 when the forged product F is formed are obtained. The corrected weight Pcor of the product part P is calculated by subtracting the corrected weight of the product part P from the weight Pw of the product part P, and the lack of the product part P is calculated based on the corrected weight Pcor of the product part P. And a lacking thickness determining means 10 for determining.

Further, the forging inspection method of the forged product according to the present invention is to roughly form the forged product F including the product part P and the burr B by forging the material f with the forging dies 1 and 2, and forging the F For removing the burr B from the product part P of the product and determining the lack of the product part P, the weight Pw of the product part P is obtained, and the opening fluctuations of the forging dies 1 and 2 when the forged product F is formed The corrected weight of the product part P is obtained, and the corrected weight Pcor of the product part P is calculated by subtracting the corrected weight of the product part P from the weight Pw of the product part P, and the corrected weight of the product part P is calculated. The lack of the product part P is determined based on Pcor.
Furthermore, in addition to the above-described configuration, the method for inspecting the forging F of the forged product F according to the present invention includes the measured value Bt and the set value Bs of the burr B, or the measured value Pt and the set value of the thickness of the product part P. The corrected weight of the product portion P is obtained by multiplying the difference (Bt−Bs) and (Pt−Ps) from Ps by the projected area M of the product portion P and the material density d.
Furthermore, in addition to the above-described configuration, the forging product F lacking inspection method of the present invention compares the corrected product part weight Pcor with a threshold value so that the product part P is within the lacking limit level. It is determined whether or not there is.

  As the material f for manufacturing the crankshaft, for example, a rod-shaped billet is used. The forging dies 1 and 2 are, as necessary, a preforming die for forming the rod-shaped billet f into a rough shaped material of a predetermined shape, a rough forming die for roughing the rough shaped material to a rough shape of a predetermined shape, and rough finishing. A finishing die for forming a forged product F in which burrs B are formed around a portion (product portion P) that becomes a crankshaft of the roughed waste, and a trimming die for removing the burrs B of the forged product F to obtain a product portion P Are arranged in a forging press. By sequentially transferring to each die, as shown in FIG. 1, a forged product F in which a burr B is formed around a product part P and its periphery is formed from a rod-shaped billet f, and the burr B is removed and discharged. At the same time, the product part P is taken out.

  In this embodiment, the thickness detecting device includes a material weight measuring device 11 whose weight measuring means measures the weight fw of the bar-shaped billet f, and a burr B removed from the product part P and discharged from the forging dies 1 and 2. And a burr weight measuring device 12 for measuring the weight Bw of the burrs B removed from the product portion P and discharged from the forging dies 1 and 2 (within the forging die). A burr thickness measuring device 13 for measuring the mold opening / closing direction (Bt) is provided. In this embodiment, the burr weight measuring device 12 and the burr thickness measuring device 13 are integrated into a burr weight / burr thickness measuring device 14. Further, the lacking thickness determining means 10 is preliminarily inputted and stored with information on the set value Bs of the thickness of the burr B, the extraction area (projected area of the product portion P) M of the forged product F, and the material density d. And storage means for receiving the signals output from the material weight measuring device 11 and the burr weight / burr thickness measuring device 14 and processing them together with the stored information as will be described later.

  In the thinning detection device configured as described above, the weight fw of the bar-shaped billet f before being set on the forging dies 1 and 2 is measured by the material weight measurement device 11, and the measurement result is sent to the thinning evaluation means 10. Send. And about the burr | flash B removed from the product part P of the forged product F shape | molded from the rod-shaped billet f and discharged | emitted, while measuring the weight Bw with the burr weight / burr thickness measurement apparatus 14, and measuring thickness Bt These measurement results are transmitted to the lack evaluation means 10.

The lacking thickness evaluation means 10 calculates the weight Pcor after correction of the product part P by executing the calculation of the following equation (1).
Pcor = (fw−Bw) − [(Bt−Bs) × M × d] (1)
That is, the weight Pw of the product part P from which the burrs B of the forged product F are removed can be obtained by subtracting the weight Bw of the burrs B from the measured weight fw of the bar-shaped billet f. Further, the thinning evaluation means 10 multiplies the value obtained by subtracting the preset value Bs stored in advance from the measured value Bt of the burr B by the blank area M of the forged product P and the material density d. This multiplication result means an error (a corrected weight of the product part) with respect to the set value Pw of the weight of the molded product part P.

  Here, (a) to (c) of FIGS. 4A and 4B show a case where the opening amount of the forging dies 1 and 2 at the time of forming fluctuates in the portion where the journal portion of the crankshaft of the forging dies 1 and 2 is formed. Is shown. The center (a) of FIG. 4 shows the case where the opening amounts of the forging dies 1 and 2 are set, and the right (b) of FIG. (C) on the left side of FIG. 4 shows the case where the opening amount of the forging die is smaller than the setting, respectively.

  When the opening amount of the forging dies 1 and 2 fluctuates more than the setting (b), the thickness of the burr B is larger than that when the opening amount of the forging dies 1 and 2 is as set (a) ( Bta <Btb), and accordingly, the thickness of the hatched portion of the product part P also fluctuates so as to increase, so that the weight Pw of the product part P is greater than in the case of (a) ( It fluctuates so that the case of b) becomes heavier. Therefore, in the case of (b), since the weight Pw of the product part P is a measured value that exceeds the case of (a) even if the product part P is missing, It may not be generated or may be erroneously determined as being small even if it has occurred.

  On the other hand, when the opening amount of the forging dies 1 and 2 fluctuates smaller than the setting (c), the thickness of the burr B is smaller than that when the opening amount of the forging dies 1 and 2 is as set (a). When the weight Pw of the product part P is (a), since the thickness of the part hatched so as to intersect with the product part P also changes so as to be small (Bta> Btc). In other words, the case (c) varies so as to become smaller (lighter). Therefore, in the case of (c), since the weight Pw of the product part P is a measured value lower than the case of (a) even if the product part P is not thin, May occur, or it may be erroneously determined that a large undercut has occurred.

  Therefore, in the present invention, when inspecting the lack of the product part P based on the weight Pw of the product part P, in order to accurately inspect the lack of the product part P, the variation in the opening amount when the forging dies 1 and 2 are formed is changed. Accordingly, the fluctuation of the weight Pw of the product part P is corrected.

  More specifically, if the measured value Bt of the burr thickness is the same as the preset value Bs stored in advance (in the case of FIG. 4A), the subtracted value is zero and the multiplication result is also zero. Thus, the corrected weight of the product part P is also zero. Therefore, the weight Pw of the product part P obtained previously is the value (Pcor = Pw) as it is, and whether or not the product part P is missing is described later. Thus, it can be used for determining whether or not the lack of the product part P is within the limit.

  If the measured value Bt of the burr thickness is larger than the preset value Bs stored in advance ((b) in FIG. 4), the measured value Bt of the burr thickness and the preset value Bs stored in advance And the multiplication result (the corrected weight of the product part P) of the forging product F and the material density d is also positive. Therefore, if the value Pcor obtained by subtracting the corrected weight of the product part P from the previously obtained weight Pw of the product part P is whether or not the product part P is missing, or if there is a missing part As will be described later, it can be used for determining whether or not the lack of the product part P is within the limit.

  On the other hand, when the measured value Bt of the burr B is smaller than the preset value Bs stored in advance ((c) in FIG. 4), the measured value Bt of the burr thickness and the preset value Bs stored in advance. And the result of multiplying the forged product extraction area M by the material density d (corrected weight of the product part) is also negative. Therefore, if the value Pcor obtained by adding the corrected weight of the product part P to the previously obtained weight Pw of the product part P is a missing part in the product part P or not, As will be described later, it can be used for determining whether or not the lack of the product part P is within the limit. That is, in the present invention, “subtracting the corrected weight of the product part from the weight of the product part” means that the weight Pw of the product part P is substantially obtained when the corrected weight of the product part P is negative (minus). Includes the case where the corrected weight of the product part P is added.

  In this embodiment, the weight fw of the bar-shaped billet f before being set in the forging dies 1 and 2 is measured and removed from the product part P of the forged product F formed from the bar-shaped billet f. The weight Bw and thickness Bt of the burr B discharged from 2 are measured. That is, it is not necessary to measure the weight and thickness of the material f, the waste land, and the forged product F in the forging dies 1 and 2. Therefore, since it is not necessary to interrupt the forging process, the lack inspection can be performed without taking time. Further, the burr weight / burr thickness for measuring the weight Bw and the thickness Bt of the burr B removed and discharged from the raw material weight measuring device 11 for measuring the weight fw of the bar-shaped billet f and the product part P of the forged product F. Since the measuring device 14 can be easily provided outside the forging dies 1 and 2, a general-purpose one can be used, so that the inspection device can be manufactured inexpensively and easily, and the forging die The changeover for changing 1 and 2 can be easily performed.

Next, another embodiment of the present invention will be described in detail mainly based on FIG. Note that portions that are the same as or correspond to those in the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and only different portions are described.
In this embodiment, the missing thickness detecting device includes a product part weight measuring device 15 in which the weight measuring unit directly measures the weight Pw of the product part P from which the burrs B of the forged product F are removed, and the thickness is measured. The measuring device includes a product part thickness measuring device 16 that measures the thickness P of the product part P (the mold opening / closing direction when it is in the forging die) Pt. In this embodiment, the product part weight measuring device 15 and the product part thickness measuring device 16 are integrated into a product part weight / thickness measuring device 17. Further, the lacking wall evaluation means 10 in this embodiment obtains information on the set value Ps of the thickness of the product part P, the extraction area (projected area of the product part) M of the forged product F, and the material density d in advance. Storage means for inputting and storing, and arithmetic means for receiving signals output from the product part weight measuring device 15 and the product part thickness measuring device 16 and performing arithmetic processing as described later together with stored information. .

  In the thinning detection apparatus configured as described above, the weight Pw of the product part P from which the burr B of the forged product F has been removed by the product part weight measurement device 15 of the product part weight / thickness measurement device 17 is directly set. While measuring, the thickness Pt is measured, and the measurement result is transmitted to the lack evaluation means 10.

The lacking thickness evaluation means 10 calculates the weight Pcor after correction of the product part P by executing the calculation of the following equation (2).
Pcor = (Pw) − [(Pt−Ps) × M × d] (2)
That is, in the thinning evaluation means 10, a calculation process for multiplying the value obtained by subtracting the preset value Ps stored in advance from the measured value Pt of the thickness of the product part P by the extraction area M of the forged product F and the material density d. To calculate the error (corrected weight of the product part) with respect to the set value Pw of the weight of the molded product part P, and subtract the corrected weight from the directly measured weight Pw of the product part P. Then, the corrected weight Pcor of the corrected product part P is obtained. That is, the corrected weight of the product part is the difference between the measured value Bt of the burr B and the set value Bs as in the above-described embodiment, and the thickness of the product part P as in this embodiment. It can be obtained from any of the difference between the measured value Pt and the set value Ps.

  More specifically, if the measured value Pt of the thickness of the product part P is the same as the preset value Ps stored in advance ((a) in FIG. 4), the subtracted value is zero and the multiplication result is also zero. Thus, the corrected weight of the product part P is also zero. Therefore, the weight Pw of the product part P obtained previously is the value (Pta = Ps) as it is, and whether or not the product part P is missing or not is described later. Thus, it can be used for determining whether or not the lack of the product part P is within the limit.

  When the measured value Pt of the thickness of the product part P is larger than the preset value Ps stored in advance ((b) of FIG. 4), the measured value Pt of the thickness of the product part P is stored in advance. The difference from the set value Ps becomes positive, and the multiplication result (corrected weight of the product part) of the forged product F withdrawn area M and the material density d also becomes positive. Therefore, if the value Pcor obtained by subtracting the corrected weight of the product part P from the previously measured weight Pw of the product part P is a missing part in the product part P, or if there is a missing part. As will be described later, it can be used for determining whether or not the lack of the product part P is within the limit.

  On the other hand, if the measured value Pt of the thickness of the product part P is smaller than the preset value Ps stored in advance, the difference between the measured value Pt of the product part P and the preset value Ps stored in advance is negative. Thus, the multiplication result (corrected weight of the product part) of the punched area M of the forged product F and the material density d is also negative. Therefore, the value Pcor obtained by adding the corrected weight of the product part P to the previously measured weight Pw of the product part P is whether or not the product part P is lacking, and when the lacking part is occurring. As will be described later, it can be used for determining whether or not the lack of the product part P is within the limit. In the present invention, “subtracting the corrected weight of the product part from the weight of the product part” means that the weight Pw of the product part P is substantially when the corrected weight of the product part P is negative (minus). It is the same as in the above-described embodiment that the case where the corrected weight of the product part P is added to the above.

  In this embodiment, the burrs B of the forged product F are removed, and the weight Pw of the product part P taken out from the forging dies 1 and 2 and the thickness Pw of the product part P are directly measured. That is, it is not necessary to measure the weight and thickness of the material f, the waste land, and the forged product F in the forging dies 1 and 2. Therefore, since it is not necessary to interrupt the forging process, the lack inspection can be performed without taking time. The product part weight measuring device 15 for measuring the weight Pw of the product part P and the product part thickness measuring device 16 for measuring the thickness Tw of the product part P are easily provided outside the forging dies 1 and 2. Therefore, since a general-purpose one can be used, the inspection apparatus can be manufactured inexpensively and easily, and the changeover for changing the forging dies 1 and 2 can be easily performed. In this embodiment, since the configuration is simpler than that of the above-described embodiment, the inspection apparatus can be manufactured more inexpensively and easily than the above-described embodiment.

  Next, whether or not the product portion P performed by the lacking evaluation means 10 of the present invention has a missing portion, and whether or not the missing portion is within the limit when the missing portion has occurred. The determination will be described. As described above, as shown in FIG. 5, the weight Pcor of the product part P in which the weight due to the opening variation of the forging dies 1 and 2 is corrected by the corrected weight obtained by the formulas (1) and (2) is as shown in FIG. Maximum without meat. On the other hand, when there is a lack, the corrected weight Pcor of the product part P decreases. If the lacking thickness is small, a product such as a desired crankshaft may be manufactured by performing precision machining or the like in a later process. However, if the undercutting is large, a desired product such as a crankshaft cannot be manufactured by machining in a later process. In this way, the level at which a desired product is allowed to be manufactured in a later process, that is, the limit level for lacking is naturally determined depending on the size of the lacking thickness. In the present invention, when the size of the lacking meat is smaller than the lacking limit level, it is called “within the lacking limit”, and when the lacking occurs, the lacking size is within the lacking limit. It is determined whether or not.

  As shown in FIG. 5, when the size of the lacking part is within the lacking part limit, the weight Pcor of the product part P corrected as described above becomes a predetermined value or more. In other words, if the weight Pcor of the product part P corrected as described above is equal to or greater than a predetermined value, it can be said that the size of the lacking wall is within the lacking wall limit. Therefore, in the present invention, a threshold value is set for the corrected weight Pcor of the product part, and if the corrected weight Pcor of the product part P is equal to or larger than the threshold value, the size of the lacking part is within the lacking part limit. Yes, when the corrected weight Pcor of the product part P is lower than the threshold value, it is determined that the size of the lacking part has exceeded the lacking part limit. When it is determined that the size of the lacking wall has exceeded the lacking wall limit, a visual or audible warning signal can be issued to alert the work supervisor. Feedback control can be performed so that the opening of the material f is reduced or the weight fw of the material f is increased, that is, the cutting length of the bar-shaped billet f is increased.

  According to the present invention, it is possible to determine whether or not the product portion is thin by merely determining whether or not the corrected weight Pcor of the product portion has reached a predetermined maximum value. Then, a threshold value is set for the corrected weight Pcor of the product part P, and when the lack of the thickness occurs, the calculated actual product part weight Pcor is compared with the threshold value, and the correction is made. Only by determining whether or not the weight Pcor of the finished product part P has exceeded the threshold value, it can be determined whether or not the size of the lacking part has exceeded the lacking part limit.

  The present invention is not limited to the case of manufacturing a crankshaft of an automobile engine as the forged product F to be subjected to the lacking inspection, and is also applicable to the case of forming a forged product for manufacturing other products. can do.

It is the schematic shown in order to demonstrate one Embodiment of the lack inspection method and the apparatus of the forge goods by this invention. It is the schematic shown in order to demonstrate 2nd Embodiment of the lack inspection method and apparatus of the forge by this invention. It is explanatory drawing which showed the matter measured in each shaping | molding step. It is explanatory drawing which showed the state from which the thickness of the burr | flash of a forged product and the thickness of a product part fluctuate | varied as it fluctuates so that the opening amount of the forging die at the time of shaping | molding may increase / decrease. It is the graph which showed the magnitude | size of the lacking part with respect to the weight of the corrected product part.

Explanation of symbols

F: forged product, f: material, P: product part, B: burr, Pw: weight of product part, fw: weight of material, Bw: weight of burr, Bt: measured value of burr thickness, Bs: burr Pt: measured thickness of the material, Ps: set value of burr thickness, M: burr removal area, d: material density, Pcor: corrected weight of product part, 1, 2: Forging die, 10: Chipping judgment means, 11: Material weight measuring device, 12: Burr weight measuring device, 13: Burr thickness measuring device, 14: Burr weight / thickness measuring device, 15: Product part weight Measuring device 16: Product part thickness measuring device 17: Product part weight / thickness measuring device

Claims (4)

An inspection method for forming a forged product including a product part and a burr by forging the material with a forging die, removing the burr from the product part of the forged product, and determining a lack of product part ,
In addition to obtaining the weight of the product part, obtain the corrected weight of the product part due to the forging die opening fluctuation at the time of forming the forged product,
Subtract the weight of the product part from the weight of the product part to correct the weight of the product part,
A method for inspecting a lack of a forged product, comprising: determining a lack of a product portion based on the corrected weight of the product portion.   The corrected weight of the product part is obtained by multiplying the difference between the measured value of the thickness of the burr or the thickness of the product part and the set value by the projected area of the product part and the material density. The forging inspection method for forgings according to 1.   3. The forging inspection of a forged product according to claim 1, wherein it is determined whether the thickness of the product portion is within a limit by comparing the corrected weight of the product portion with a threshold value. 4. Method. An inspection device for determining a lack of a product part from which a burr has been removed of a forged product formed by forging a material with a forging die,
A weight measuring means for measuring the weight of at least one of the material, the product part and the burr;
A thickness measuring means for measuring at least one thickness of the product portion and the burr;
Obtain the weight of the product part, obtain the corrected weight of the product part due to the forging die opening fluctuation at the time of forming the forged product, and subtract the corrected part weight of the product part from the weight of the product part to correct the weight of the product part And a lack determination unit for determining a lack of product part based on the corrected weight of the product part,
A forging missing thickness detecting device characterized by comprising:

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