JP2005238332A - Die casting machine, method for controlling casting condition, and method for evaluating quality of casting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die casting machine in which casting conditions can be precisely adjusted and the quality of a casting can be improved. <P>SOLUTION: The die casting machine comprises: a pressure detector 31 for detecting casting pressure Pcy generated by an injection apparatus; a pressure detector 30 for detecting pressure Pca acting on molten metal filled in a cavity; a transfer property calculating part 62 for calculating the transfer properties of the casting pressure Pcy generated by the injection apparatus to the molten metal filled in the cavity on the basis of the casting pressure Pcy and the pressure Pca in the cavity; and a casting condition controlling part 63 for controlling the casting conditions in a casting molded in the cavity on the basis of the transfer properties calculated by the transfer property calculating part 62. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a die casting machine, a method for adjusting casting conditions, and a quality evaluation method for cast products.

The die casting machine injects and fills a molten metal into a cavity formed between molds by an injection device in a state in which a pair of molds is clamped, and further, the pressure (casting) of the molten metal filled in the cavity. (Pressure) is increased to form a cast product.
Increasing the casting pressure of the molten metal filled in the cavity compresses the molten metal in the cavity, thereby releasing the gas entrained by the molten metal and preventing the occurrence of defects inside the casting. Is for etc. Therefore, if the casting pressure is not properly transmitted to the molten metal in the cavity, the quality of the cast product may be deteriorated.

By the way, the evaluation of whether or not the casting pressure generated by the injection device is acting properly on the molten metal filled in the cavity is evaluated by actually analyzing the quality of the cast product.
On the other hand, the transmission efficiency of the casting pressure generated by the injection device in the molten metal filled in the cavity is affected by various casting conditions such as the temperature of the molten metal, the temperature of the mold, and the operating conditions of the injection device. . For this reason, after actually analyzing the quality of the cast product, it is necessary to adjust various casting conditions such as the temperature of the molten metal, the temperature of the mold, and the operating conditions of the injection device using this result. It takes a very long time to adjust the casting conditions. Further, since it is difficult to quantitatively adjust the casting conditions using the analysis result of the quality of the cast product, it is difficult to precisely adjust the casting conditions.
Furthermore, since it is not possible to analyze the quality of all of the molded castings, the quality assurance of the castings may not be sufficient.

  The present invention has been made in view of the above-described problems, and its object is to provide a die casting machine capable of precisely adjusting casting conditions and improving the quality of cast products, a method for adjusting casting conditions, and a cast product. It is to provide a quality evaluation method.

  A die casting machine according to a first aspect of the present invention includes a pair of molds and an injection device that injects and fills a molten metal into a cavity formed between the pair of molds and applies casting pressure to the molten metal. A casting pressure detecting means for detecting a casting pressure generated by the injection device, an in-mold pressure detecting means for detecting a pressure acting on the molten metal filled in the cavity, and Based on the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means, the result of the transfer characteristic of the casting pressure generated by the injection device to the molten metal filled in the cavity is obtained. A transfer characteristic calculating means for calculating; and an output means for outputting a result of the transfer characteristic calculated by the transfer characteristic calculating means.

  Preferably, the transfer characteristic calculating means calculates a time change (time series data) of a ratio between the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means as the transfer characteristics. The display means displays a diagram showing a change over time in the pressure ratio.

  A die casting machine according to a second aspect of the present invention includes a pair of molds and an injection device that injects and fills a molten metal into a cavity formed between the pair of molds and applies a casting pressure to the molten metal. A casting pressure detecting means for detecting the casting pressure generated by the injection device, and an in-mold pressure detecting means for detecting the pressure acting on the molten metal injected into the cavity. Based on the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means, the transfer characteristic of the casting pressure generated by the injection device to the molten metal filled in the cavity is determined. A transfer characteristic calculating means for calculating a result, and a casting for adjusting a casting condition of a cast product formed in the cavity based on the result of the transfer characteristic calculated by the transfer characteristic calculating means Having a matter adjustment means.

  Preferably, the transfer characteristic calculating means calculates a time change (time series data) of a ratio between the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means as the transfer characteristics. The casting condition adjusting means determines whether or not the time during which the pressure ratio is maintained in a predetermined setting range is equal to a predetermined setting time, and adjusts the casting conditions when it is determined that they are not equal.

  A die casting machine according to a third aspect of the present invention includes a pair of molds and an injection device that injects and fills a molten metal into a cavity formed between the pair of molds and applies a casting pressure to the molten metal. A casting pressure detecting means for detecting a casting pressure generated by the injection device, an in-mold pressure detecting means for detecting a pressure acting on the molten metal filled in the cavity, and Based on the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means, the result of the transfer characteristic of the casting pressure generated by the injection device to the molten metal filled in the cavity is obtained. Transfer characteristic calculation means for calculating, and quality evaluation means for evaluating the quality of a cast product molded in the cavity based on the result of the transfer characteristic calculated by the transfer characteristic calculation means; A.

  Preferably, storage means for storing the transfer characteristic data in association with the quality of the cast product is further provided, wherein the transfer characteristic is detected by the casting pressure detected by the casting pressure detection means and the detection by the in-mold pressure detection means. The quality evaluation means determines whether or not the transfer characteristic calculated by the transfer characteristic calculation means approximates the transfer characteristic stored in the storage means. If it is determined, the quality of the cast product molded in the cavity is evaluated to be equivalent to the quality associated with the transfer characteristic stored in the storage means.

  The method for adjusting casting conditions according to the present invention is a casting method in which a molten metal is injected and filled in a cavity formed between a pair of molds, and then a casting pressure is applied to the molten metal filled in the cavity. A method for adjusting a casting condition of a product, wherein the casting pressure and a pressure acting on the molten metal filled in the cavity are detected, and the detected casting pressure and the molten metal filled in the cavity act on the detected molten metal. And the result of the transfer characteristic of the casting pressure from the pressure to the molten metal filled in the cavity, and based on the calculated result of the transfer characteristic, the casting conditions of the cast product molded in the cavity Adjust.

  The casting quality evaluation method of the present invention is formed by injecting and filling a molten metal into a cavity formed between a pair of molds, and then applying a casting pressure to the molten metal filled in the cavity. A casting quality evaluation method for evaluating the quality of a cast product, wherein the casting pressure and a pressure acting on a molten metal filled in the cavity are detected, and the detected casting pressure and the cavity are filled. From the pressure acting on the molten metal, the result of the transfer characteristic of the casting pressure to the molten metal filled in the cavity is calculated, and the molding is performed in the cavity based on the calculated transfer characteristic result. Evaluate the quality of cast products.

  In the present invention, the casting pressure generated by the injection device and the pressure acting on the molten metal filled in the cavity are detected, and the transfer characteristic of the casting pressure from the molten metal to the molten metal filled in the cavity is calculated. . From this transmission characteristic, it can be determined whether or not the casting pressure is properly transmitted to the molten metal filled in the cavity. This transfer characteristic has a correlation with various casting conditions, and the current casting conditions can be estimated from the obtained transfer characteristics. In addition, the higher the casting pressure transmission efficiency, the more effectively the molten metal is crushed and the defects in the casting are less likely to occur.Therefore, the casting conditions are increased so that the transmission efficiency is increased based on the detected current transmission characteristics. By adjusting, quantitative casting conditions can be adjusted, and the quality of the cast product can be improved.

According to the present invention, precise adjustment of casting conditions is possible, and the quality of cast products can be improved.
Further, according to the present invention, the quality can be evaluated without analyzing the cast product.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an overall configuration of a die casting machine according to an embodiment of the present invention.
The die casting machine 1 includes a pair of moving mold 2, fixed mold 3, injection device 4, controller 50, display device 51, input device 52, and the like.

The movable mold 2 and the fixed mold 3 are held by a mold clamping device (not shown), and the mold opening / closing and the mold clamping are performed by this mold clamping device.
A cavity C is formed between the fixed mold 3 and the movable mold 2 in a clamped state, and a molten metal such as an aluminum alloy or a magnesium alloy is injected and filled in the cavity C, thereby casting. The product is molded.
A pressure detector 30 for detecting the pressure of the molten metal filled in the cavity C is provided near the gate of the moving mold 2. This pressure detector 30 is an embodiment of the in-mold pressure detecting means of the present invention.

The injection device 4 includes a sleeve 5, a plunger 6, an injection cylinder 10, a hydraulic circuit 20, an accumulator 25, and the like.
The sleeve 5 is formed of a cylindrical member, and is provided on the back side of the fixed mold 3 so as to communicate with the cavity C. A supply port 5 a for supplying the molten metal ML is provided on the rear end side of the sleeve 5. For example, the molten metal ML measured using the ladle 100 is supplied into the sleeve 5 through the supply port 5a.
The plunger 6 includes a plunger tip 6a that fits to the inner periphery of the sleeve 5 and a plunger rod 6b that is connected to the tip of the plunger tip 6a, and the molten metal supplied to the sleeve 5 by advancing the plunger 6 ML is injected into the cavity C and filled.
A position detector 35 is provided for the plunger 6, and the position detector 35 detects the position Ps of the plunger 6 and outputs it to the controller 50. The controller 50 calculates an injection speed and the like from the position Ps of the plunger 6.

The injection cylinder 10 includes an injection cylinder chamber 11 and a boost cylinder chamber 14 that communicate with each other. The pressurizing cylinder chamber 14 has a larger diameter than the injection cylinder chamber 11. The injection cylinder chamber 11 incorporates an injection piston 12, and this injection piston 12 is connected to the plunger rod 6 b through a piston rod 13 and a coupling 8.
A boosting piston 15 having a diameter larger than that of the injection piston 12 is built in the boosting cylinder chamber 14.

The hydraulic circuit 20 is connected to the injection cylinder chamber 11 and the boost cylinder chamber 14 by a pipe line. In addition, a hydraulic pressure source 26 and an accumulator 25 are connected to the hydraulic circuit 20. The hydraulic source 26 supplies hydraulic oil with a predetermined pressure for driving the injection piston 12 to the hydraulic circuit 20, and the accumulator 25 supplies hydraulic oil with a predetermined pressure for driving the boosting piston 15 to the hydraulic circuit 20. To do.
The hydraulic circuit 20 receives a control command 50 s from the controller 50, adjusts the flow rate of the hydraulic oil supplied from the hydraulic source 26, supplies the hydraulic oil to the injection cylinder chamber 11, and controls the injection speed of the injection piston 12. Further, the hydraulic circuit 20 receives a control command 50 s from the controller 50, supplies hydraulic oil supplied from the accumulator 25 to the boosting cylinder chamber 14, and drives the boosting piston 14. The pressure of the hydraulic oil supplied to the boosting cylinder chamber 14 is the casting pressure of the present invention.

  A pressure detector 31 is provided on the back pressure side of the boosting cylinder chamber 14, and the pressure detector 31 detects the pressure of the hydraulic oil supplied to the boosting cylinder chamber 14, that is, the casting pressure Pcy, This is output to the controller 50.

The controller 50 comprehensively controls the die casting machine 1 by controlling the hydraulic circuit 20 and the like.
The display device 51 is connected to the controller 50 and is composed of, for example, a liquid crystal panel, and displays various data from the controller 50. The display device 51 (display means) is an embodiment of the output means of the present invention. The output means may be a printer or a storage device.
The input device 52 is connected to the controller 50 and is composed of, for example, a keyboard or the like, and inputs various data to the controller 50.

FIG. 2 is a functional block diagram of the controller 50. FIG. 2 shows only the functions of the main parts according to the present invention.
As shown in FIG. 2, the controller 50 includes a casting pressure input unit 60, an intracavity pressure input unit 61, a transfer characteristic calculation unit 62, a casting condition adjustment unit 63, a database 64, a casting condition holding unit 65, a control unit 66, a quality. An evaluation unit 67 and a database 68 are included.
The controller 50 includes hardware such as a processor and a memory, and necessary software, and each function shown in FIG. 2 is realized by hardware and software.
The transfer characteristic calculation unit 62 is a transfer characteristic calculation unit of the present invention, the casting condition adjustment unit 63 and the database 64 are casting condition adjustment units of the present invention, and the quality evaluation unit 67 and the database 68 are one implementation of the quality evaluation unit of the present invention. It is an aspect. The memory is an embodiment of the storage means of the present invention.

The casting pressure input unit 60 samples the casting pressure Pcy detected by the pressure detector 31 and holds time-series data of the sampled casting pressure Pcy.
The intracavity pressure input unit 61 samples the pressure Pca in the cavity C detected by the pressure detector 30, and holds time-series data of the sampled pressure Pca.

The transfer characteristic calculation unit 62 transfers the casting pressure generated by the injection device 4 to the molten metal filled in the cavity C from the time series data of the casting pressure Pcy and the time series data of the pressure Pca in the cavity C. Inf is calculated and provided to the casting condition adjustment unit 63 and the quality evaluation unit 67.
The transfer characteristic Inf includes, for example, data of a ratio (K = Pca / Pcy) between the casting pressure Pcy and the pressure Pca in the cavity C at each sampling time (where the ratio K is a transfer rate).
Specific processing in the transfer characteristic calculation unit 62 will be described later.

The casting condition holding unit 65 holds casting conditions necessary for forming a cast product by the die casting machine 1. Casting conditions include, for example, the amount of molten metal, the temperature of the molten metal, the temperature of the mold, the clamping force, the operating conditions of the injection device (for example, injection speed, casting pressure, rise time of casting pressure, etc.), etc. All the conditions necessary to form a quality casting.
The control unit 66 controls the injection device 4 of the die casting machine 1, a mold clamping device (not shown), and the like according to various casting conditions held in the casting condition holding unit 65.

The casting condition adjusting unit 63 adjusts the casting conditions of the cast product molded in the cavity C based on the transfer characteristic Inf obtained by the transfer characteristic calculating unit 62. Among various casting conditions held by the casting condition holding unit 65, casting conditions that affect the transmission characteristics of the casting pressure Pcy generated by the injection device 4 to the molten metal ML filled in the cavity C, for example, molten metal Adjust at least some of the conditions such as temperature, mold temperature, injection speed, casting pressure rise time, etc., so that the transmission characteristics are less likely to cause internal defects in the cast product and the quality of the cast product is improved. .
The database 64 holds various data necessary for adjusting the casting conditions in the casting condition adjusting unit 63.
A specific method for adjusting the casting conditions in the casting condition adjusting unit 63 will be described later.

The quality evaluation unit 67 evaluates the quality of the cast product based on the transfer characteristic Inf obtained by the transfer characteristic calculation unit 62. Since the transfer characteristic Inf has information on the transfer efficiency of the casting pressure Pcy generated by the injection device 4 to the molten metal ML filled in the cavity C and information on the change thereof, the transfer characteristic Inf is filled in the cavity C. It can be inferred how the molten metal ML is compressed. Therefore, the quality evaluation unit 67 grasps the compression state of the molten metal ML filled in the cavity C from the transfer characteristic Inf, and evaluates the quality of the molded cast product.
The database 68 holds data necessary for the quality evaluation unit 67 to evaluate the quality of the cast product.
A specific quality evaluation method in the quality evaluation unit 67 will be described later.

Next, an example of a casting process by the die casting machine 1 will be described with reference to FIG.
First, as a pre-process, the moving mold 2 is closed with respect to the solid mold 3, the moving mold 2 and the solid mold 3 are clamped, and the plunger 6 is positioned at a predetermined retracted position. Prepare (process PR1).
Next, sampling of pressure detected by the pressure detectors 30 and 31 is started on the controller 50 side (process PR2). Thereby, it becomes possible to detect the casting pressure Pcy and the pressure Pca of the molten metal ML filled in the cavity C.

Next, the molten metal is injected and filled into the cavity C by the injection device 4 (process PR3).
Injecting and filling the molten metal into the cavity C, first, a predetermined amount of the molten metal ML is supplied into the sleeve 5 through the supply port 5 a of the sleeve 5.

Next, the plunger 6 is advanced at a low speed, and when the plunger 6 reaches a predetermined speed switching position, the plunger 6 is switched at a high speed. The speed switching position is the position of the plunger 6 when the tip of the molten metal ML supplied to the sleeve 5 substantially reaches the gate of the mold.
When the plunger 6 is advanced at a high speed, the molten metal ML supplied to the sleeve 5 is injected into the cavity C. The molten metal ML injected into the cavity C entrains the gas in the cavity C. As the plunger 6 advances, the cavity C is filled with the molten metal ML and is filled with the molten metal ML.
For example, as shown by the injection speed V in FIG. 4A, the plunger 6 moves at a low speed from the time t0 to the time t1, and then switches to a high speed at the time t1, and then rapidly increases in speed and then rapidly. To slow down.
In this situation, when the molten metal ML touches the detection surface of the pressure detector 30 provided in the moving mold 2, the pressure acting on the molten metal ML is detected. Although the situation differs depending on the installation location of the pressure detector 30, even if the pressure detector 30 detects the pressure, the value is relatively low and the fluctuation is large.

  When the cavity C is filled with the molten metal ML, the plunger 6 is rapidly decelerated. At this stage, the injection device 4 is switched from speed control to pressure control, and the pressure of the molten metal ML filled in the cavity C is increased (process PR4). The pressurizing step is performed to prevent the occurrence of internal defects such as a nest due to the gas inside the cast product by compressing the molten metal ML containing the gas filled in the cavity C by applying a casting pressure. .

The pressurizing hydraulic oil is supplied to the cylinder chamber on the back side of the boosting piston 15 of the injection cylinder 10, and casting pressure is generated. For example, as shown in FIG. 4B, the casting pressure Pcy detected by the pressure detector 31 increases and reaches a predetermined value after a predetermined rise time Tm from the time t3 when the pressure increase is started.
On the other hand, the casting pressure Pcy generated in the injection cylinder 10 is transmitted to the molten metal ML filled in the cavity C. For example, as shown in FIG. 4C, the pressure Pa detected by the pressure detector 30 is the casting. It rises as the pressure Pcy rises.
FIG. 4C shows a case where the pressure Pa detected by the pressure detector 30 increases as the casting pressure Pcy increases, but in the vicinity of touching the pressure detector 30 provided on the movable mold 2. When the molten metal ML contains a large amount of gas or the molten metal ML has already started to solidify, the pressure Pca detected by the pressure detector 30 is the casting generated on the injection cylinder 10 side. The value is not equal to the pressure Pcy.

  After the pressure increasing process is completed, sampling of the pressure detected by the pressure detectors 30 and 31 is terminated on the controller 50 side (process PR5). At this time, the casting pressure input unit 60 and the in-cavity pressure input unit 61 on the controller 50 side store time series data of the casting pressure Pcy in the pressurizing step and the pressure Pca acting on the molten metal filled in the cavity C. ing.

  Thereafter, post-processes such as mold opening of the movable mold 2 with respect to the fixed mold 3, removal of the cast product, cleaning of the mold, and spraying of a release agent to the mold are performed (process PR 6), and one time. The casting cycle ends. When the casting cycle is repeated, the above steps are repeated.

Calculation of Transfer Characteristic Next, an example of processing in the transfer characteristic calculation unit 62 of the controller 50 will be described. By the casting cycle described above, the casting pressure input unit 60 and the in-cavity pressure input unit 61 are filled into the casting pressure Pcy and the cavity C in the pressurization process as shown in FIGS. 4B and 4C, for example. The time series data of the pressure Pca acting on the molten metal is stored.
The transfer characteristic calculation unit 62 calculates the ratio (K = Pca / Pcy) between the casting pressure Pcy and the pressure Pca in the cavity C. This transmission rate K changes in the range of 0 to 1, for example, as shown in FIG. When the transmission rate K is 0, it indicates that the casting pressure Pcy generated on the injection cylinder 10 side is not transmitted at all to the molten metal near the pressure detector 30 in the cavity C, and the transmission rate K is 1. Indicates that 100% is transmitted.
The transmission rate K may be calculated directly from the raw data of the pressures Pcy and Pca, or may be calculated from data obtained by performing a predetermined process such as a filtering process on the raw data. For example, the transmission rate K may be calculated after removing high-frequency vibration components (noise) from the raw data of the pressures Pcy and Pca.

The waveform of the transmission rate K as shown in FIG. 4D is affected by various casting conditions.
In the example shown in FIG. 4 (d), as the casting pressure Pcy rises at time t3, the transmission rate K also increases, and after a certain amount of time has elapsed after reaching 1, it gradually decreases toward zero. Yes. In this example, 100% of the casting pressure Pcy is immediately transmitted to the molten metal in the cavity C from the time t3, and after being compressed for a certain period of time with a force equal to the casting pressure Pcy, solidification starts near the time t4. It shows that. The reason why the pressure decreases when the molten metal solidifies is that the pressure acting on the molten metal is hardly transmitted to the pressure detector 30.
If the transmission rate K is maintained at 1 for a certain period of time, it can be estimated that the casting pressure Pcy has been transmitted 100% and sufficient compression has been performed.

  The transfer characteristic calculation unit 62 displays various waveform data including the transfer rate K as shown in FIG. The operator of the die casting machine 1 can quantitatively grasp the state according to the current casting conditions by observing the waveform data of the transmission rate K on the display device 51.

  Each waveform data shown in FIG. 4 is an example when the casting pressure Pcy is appropriately transmitted to the molten metal, but an example when the rising time Tm of the casting pressure Pcy as a casting condition is changed (extended). Is shown in FIG.

  As shown in FIG. 5B, when the rise time Tm of the casting pressure Pcy is extended to Tm ′, the pressure Pa in the cavity C shown in FIG. 5C increases with the generation of the casting pressure Pcy. The casting pressure Pcy decreases without following the casting pressure Pcy. For this reason, the transmission rate K increases from 0 to 1, and then reaches 0 without reaching 1. This is because the rise time Tm ′ of the casting pressure Pcy is too long, so that the solidification of the molten metal starts before the rise time Tm ′ elapses, that is, before the predetermined value of the casting pressure Pcy is reached. is there. Under such casting conditions, the molten metal in the vicinity of the pressure detector 30 is solidified without being sufficiently compressed, and there is a high possibility that defects such as nests are generated inside the cast product.

Thus, the value of the transmission rate K and the time change of the transmission rate K change depending on casting conditions such as the rise time Tm of the casting pressure Pcy. The casting conditions that affect the transmission rate K include not only the rise time Tm of the casting pressure Pcy, but also a plurality of others.
Therefore, since the operator of the die casting machine 1 can empirically grasp the correlation between the transmission rate K, various casting conditions, and the quality of the cast product, the required quality of the cast product is satisfied while observing the waveform of the transmission rate K. It becomes possible to adjust casting conditions. In other words, by making the value of the transmission rate K and the change over time one of the indices when adjusting the casting conditions, the adjustment of the casting conditions becomes easy and can be adjusted quantitatively and precisely. Adjustment is possible.

Adjustment of the casting conditions will be described an example of a process of casting condition adjusting unit 63.
As described above, there is a correlation between the transmission rate K and the quality of the cast product, and there is also a correlation between the transmission rate K and the casting conditions. Therefore, it is possible to quantify the correlation between the transmission characteristic such as the value of the transmission rate K and the temporal change of the transmission rate K, the quality of the casting, and the casting conditions. The database 64 is for storing data quantifying these correlations.
The casting condition adjustment unit 63 may adjust the casting condition for each casting, or may determine whether a predetermined condition is satisfied, and may adjust the casting condition when it is determined that the condition is satisfied. For example, the casting condition adjustment unit 63 sets a time during which the transmission rate K calculated by the transmission characteristic calculation unit 62 is maintained within a preset setting range (for example, 0.9 or more) and a preset setting time. In comparison, when it is determined that the maintained time is not equal to the set time, the casting conditions in the subsequent casting may be adjusted. The setting range and setting time are held in a storage device such as a memory included in the controller 50, for example. The set time may have a predetermined width in consideration of various circumstances such as a measurement error and an allowable time difference.
The casting condition adjustment unit 63 searches or calculates, for example, a casting condition that improves the quality of the cast product from various data stored in the database 64. For example, when the time during which the transmission rate K is maintained within the set range is shorter than the set time, the condition for increasing the temperature of the molten metal, the condition for increasing the temperature of the mold, the boosting piston in the boosting process Search and calculate a condition for increasing the pressure increase of the hydraulic pressure of 15 at a higher speed.
For example, the casting condition adjustment unit 63 can also display various newly found casting conditions on the display device 51 as shown in FIG. The operator can correct various casting conditions after adjustment by the casting condition adjusting unit 63 while watching this.
Thus, by automating or semi-automating the casting condition adjustment work, the time required for the casting condition adjustment work can be shortened and the adjustment accuracy can be increased.
Further, by correlating the correlations obtained from a large number of experimental data and storing them in the database 64, the empirical rules accumulated by the operator who forms the cast product by the die casting machine 1 can be quantified. Although the operator can manually adjust the transmission characteristics such as the value of the transmission rate K and the change over time as an index for adjusting the casting conditions while observing it, the method of adjusting the casting conditions varies depending on the operator. By making it into data, it is possible to suppress variations in the adjustment of casting conditions.

Next, an example of processing of the quality evaluation unit 67 will be described.
As described above, there is a correlation between the transmission characteristics such as the value of the transmission rate K and the temporal change of the transmission rate K and the quality of the cast product. The database 68 is for storing data quantifying these correlations.
The quality evaluation unit 67 refers to, for example, the correlation data between the transmission characteristics such as the value of the transmission rate K and the temporal change of the transmission rate K stored in the database 68 and the quality of the cast product, and the transmission rate obtained for each casting. From K, the quality of the cast product is evaluated. The quality evaluation unit 67 displays the evaluation result on the display device 51.
For example, in the case of the graph (1) shown in FIG. 7 when casting is performed under the same casting conditions, a non-defective product having no internal defects is obtained, and the transmission rate K in the graphs (2) and (3) is obtained. In the case of the waveform, it is assumed that an internal defect has occurred in the cast product. Such data is stored in the database 68, and the waveform of the transmission rate K obtained for each casting is compared with the graphs (1) to (3). When the graphs (2) and (3) are approximated, it can be determined as a defective product.
Whether to approximate is determined from the viewpoint of the absolute value of the transmission rate K and the pattern of change of the transmission rate K. The determination from the viewpoint of the absolute value of the transmission rate K is, for example, the transmission rate K obtained for each casting at the same time on the basis of a predetermined time (for example, time t3 in FIG. 4) and graphs (1) to (3). The difference between the transmission rate K and the transmission rate K is calculated over a predetermined time length, and it is determined whether or not the maximum value or average value of the difference exceeds a predetermined threshold value. The determination from the viewpoint of the pattern of change of the transmission rate K is, for example, the transmission rate K obtained for each casting at the same time on the basis of a predetermined time (for example, time t3 in FIG. 4), and graphs (1) to (1). The transmission rate K in (3) is a bivariate corresponding to each other, and the determination is made based on whether or not the correlation coefficient of the bivariate is greater than a predetermined threshold.
Note that the evaluation method of the quality evaluation unit 67 is not limited to this method, and various aspects can be adopted. For example, a defective product may be determined when the time during which the transmission rate K is maintained within the above-described setting range is shorter than or equal to the set time.

By performing quality evaluation for each casting from the waveform data of the transmission rate K, it is possible to evaluate the quality without actually analyzing the cast product, and the accuracy of quality assurance of the cast product can be improved. In other words, whether or not there is a defect in the cast product is not known unless it is actually inspected, but if the waveform data of the transmission rate K obtained for each casting is abnormal, it is determined as a defective product. Therefore, it is possible to prevent defective products from being shipped.
Further, by accumulating correlation data between transmission characteristics such as the value of the transmission rate K and the temporal change of the transmission rate K in the database 68 and the quality of the cast product, the evaluation accuracy can be improved.

The present invention is not limited to the embodiment described above.
In the embodiment described above, the case where the single pressure detector 30 is provided in the moving mold 2 has been described. However, a plurality of pressure detectors may be provided in different locations of the moving mold 2 and the fixed mold 3. It is. Although the waveform data of the transmission rate K obtained from a plurality of pressure detectors are different, it is possible to adjust the casting conditions and evaluate the quality by using all of them.

It is a figure showing the whole die-casting machine composition concerning one embodiment of the present invention. 3 is a functional block diagram of a controller 50. It is process drawing which shows an example of the casting process by the die-casting machine. It is a graph which shows an example of the waveform of injection speed, casting pressure, pressure in a cavity, and a pressure transmission rate. It is a graph which shows an example of the waveform of the injection speed, casting pressure, pressure in a cavity, and pressure transmission rate when casting conditions are inappropriate. It is a figure for demonstrating an example of the adjustment method of casting conditions. It is a figure which shows an example of the waveform data of a transmission rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Die casting machine 2 ... Fixed mold 3 ... Moving mold 4 ... Injection device 5 ... Sleeve 6 ... Plunger 10 ... Injection cylinder 12 ... Injection piston 15 ... Boosting piston 50 ... Controller 60 ... Casting pressure input part 61 ... Cavity Internal pressure input unit 62 ... transfer characteristic calculation unit 63 ... casting condition adjustment unit 67 ... quality evaluation unit

Claims (9)

A die casting machine having a pair of molds and an injection device that injects and fills molten metal into a cavity formed between the pair of molds and applies casting pressure to the molten metal,
A casting pressure detecting means for detecting a casting pressure generated by the injection device;
An in-mold pressure detecting means for detecting a pressure acting on the molten metal filled in the cavity;
Based on the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means, the result of the transfer characteristic of the casting pressure generated by the injection device to the molten metal filled in the cavity Transfer characteristic calculating means for calculating
A die casting machine comprising: output means for outputting the result of the transfer characteristic calculated by the transfer characteristic calculating means. The transfer characteristic calculation means calculates a change over time in the ratio between the casting pressure detected by the casting pressure detection means and the pressure detected by the in-mold pressure detection means as the transfer characteristics,
The die casting machine according to claim 1, wherein the display means displays a graph showing a change with time in the pressure ratio. A die casting machine having a pair of molds and an injection device that injects and fills molten metal into a cavity formed between the pair of molds and applies casting pressure to the molten metal,
A casting pressure detecting means for detecting a casting pressure generated by the injection device;
In-mold pressure detecting means for detecting the pressure acting on the molten metal injected and filled in the cavity;
Based on the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means, the result of the transfer characteristic of the casting pressure generated by the injection device to the molten metal filled in the cavity Transfer characteristic calculating means for calculating
A die casting machine comprising: casting condition adjusting means for adjusting a casting condition of a cast product formed in the cavity based on the result of the transfer characteristic calculated by the transfer characteristic calculating means. The transfer characteristic calculation means calculates a change over time in the ratio between the casting pressure detected by the casting pressure detection means and the pressure detected by the in-mold pressure detection means as the transfer characteristics,
4. The casting condition adjusting means determines whether or not a time during which the pressure ratio is maintained in a predetermined setting range is equal to a predetermined setting time, and adjusts the casting conditions when it is determined that they are not equal. Die casting machine as described in. The die casting machine according to claim 3, wherein the casting conditions include any one of a temperature of the molten metal, a temperature of the mold, and an operating condition of the injection device. A die casting machine having a pair of molds and an injection device that injects and fills molten metal into a cavity formed between the pair of molds and applies casting pressure to the molten metal,
A casting pressure detecting means for detecting a casting pressure generated by the injection device;
An in-mold pressure detecting means for detecting a pressure acting on the molten metal filled in the cavity;
Based on the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means, the result of the transfer characteristic of the casting pressure generated by the injection device to the molten metal filled in the cavity Transfer characteristic calculating means for calculating
A die casting machine comprising: quality evaluation means for evaluating the quality of a cast product molded in the cavity based on the result of the transfer characteristic calculated by the transfer characteristic calculation means. And further comprising storage means for storing the transfer characteristic data in association with the quality of the casting,
The transfer characteristic is a change over time in the ratio between the casting pressure detected by the casting pressure detecting means and the pressure detected by the in-mold pressure detecting means,
The quality evaluation unit determines whether or not the transfer characteristic calculated by the transfer characteristic calculation unit approximates the transfer characteristic stored in the storage unit. If it is determined that the transfer characteristic is approximated, the quality evaluation unit is molded in the cavity. The die casting machine according to claim 6, wherein the quality of the cast product is evaluated as being equivalent to the quality associated with the transfer characteristic stored in the storage unit. After casting and filling a molten metal into a cavity formed between a pair of molds, the casting condition of the casting product is adjusted by applying casting pressure to the molten metal filled in the cavity. An adjustment method,
The casting pressure and the pressure acting on the molten metal filled in the cavity are detected, and from the detected casting pressure and the pressure acting on the molten metal filled in the cavity, the casting pressure in the cavity is detected. Calculate the result of the transfer characteristics to the molten metal filled in
A casting condition adjusting method for adjusting a casting condition of a cast product molded in the cavity based on the calculated result of the transfer characteristic. Cast metal quality is evaluated by injecting and filling molten metal into a cavity formed between a pair of molds and then applying casting pressure to the molten metal filled in the cavity. An evaluation method,
The casting pressure and the pressure acting on the molten metal filled in the cavity are detected, and from the detected casting pressure and the pressure acting on the molten metal filled in the cavity, the casting pressure in the cavity is detected. Calculate the result of the transfer characteristics to the molten metal filled in
A quality evaluation method for a cast product, wherein the quality of the cast product molded in the cavity is evaluated based on the calculated result of the transfer characteristic.

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