JPH0228454B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention utilizes the toggle mold clamping action of a molding machine such as a die casting machine or an injection molding machine to, for example,
If a crack occurs in the tie bar or platen, etc.
The present invention relates to a method for detecting abnormalities in a toggle type mold clamping device for a molding machine, which detects abnormalities that occur in the machine itself, such as loosening of tie bar nuts or rattling of toggle pins.

[Prior Art] Conventionally, injection molding machines such as die casting machines and injection molding machines have been equipped with fixed platens fixed to tie bars and movable platens that move along the tie bars. In this case, a fixed mold and a movable mold are respectively fixed. During molding, the mold is generally clamped and opened by moving a movable platen forward and backward using a mold clamping cylinder via a toggle mechanism or the like.

In a molding machine with such a toggle-type mold clamping device, it is generally difficult to control the mold clamping force, and sometimes the load on the tie bars increases due to burrs getting caught between the clamped molds or thermal expansion of the mold. It may become excessive. Furthermore, the cyclic loads acting on mechanical parts themselves such as the platen, tie bars, tie bar nuts, and toggle links may approach allowable values during long-term operation. Therefore, in such a case, if you continue to operate as it is, there is a risk of a major accident resulting in damage to mechanical parts such as the platen, tie bars, tie bar nuts, etc., which is not only extremely dangerous, but even if a major accident occurs, Even if not, the operating rate of the machine will drop significantly due to the production and replacement of damaged parts.

Therefore, it is desirable to detect and prevent these in advance.

By the way, although the object and structure are different from the present invention, as described in Japanese Patent Application Laid-Open No. 124063/1983, foreign matter such as burrs between molds clamped by a direct pressure mold clamping device is disclosed. There is a known invention that detects whether or not the mold is clamped and whether or not the final mold clamping state becomes normal.

The method described in Japanese Patent Application Laid-Open No. 54-124063 uses a direct pressure type mold clamping device to prevent damage to the mold due to foreign matter caught between the molds, or to prevent foreign matter from being removed during injection. It is effective in preventing molten metal from blowing out forcefully from between the sandwiched molds, and it can be determined whether or not there is a foreign object sandwiched between the molds based on the change in pressure as shown in Figure 6. are doing.

That is, in the case shown in FIG. 6, the mold clamping pressure P changes as the time T elapses, from the mold closing high speed section A up to time t ₁ to the mold closing slow section A from time t ₁ to time t ₂ . When the pressure changes in the mold protection zone B and the final pressurization zone D after time _t2 , the pressure curve will be as shown by the solid line under normal conditions with no foreign matter sandwiched between the molds. , the pressure is below the monitoring pressure value E in the mold protection zone B, and after time t ₂ the pressure suddenly exceeds the monitoring pressure value E, but if there is an abnormal state where a foreign object is caught between the molds, As shown by the dotted line in FIG. 6, the pressure reaches the monitored pressure value E at time _t3 , which is before time _t2 when the mold protection zone B ends, so it is necessary to detect the occurrence timing at this time _t3 . It is detected whether there is a foreign object caught between the molds. If a foreign object is caught between the molds, mold closing is stopped at time _t2 , so the pressure P is also set to 0 kg/ ^cm2 .

On the other hand, conventionally, there has been a method of detecting the elongation of a tie bar as a method of detecting the occurrence of an abnormality as described above.

Now, in order to make it easier to understand the problem to be solved by the present invention and the present invention, which will be described later, the structure and characteristics of a general toggle type mold clamping device will be explained.

FIG. 2 is a general configuration diagram of a general toggle type mold clamping device. In FIG. 2, a link housing 3 is placed on the machine base 2 of the toggle type mold clamping device 1.
and a fixed platen 4 are erected at both ends facing each other, and these are connected by four tie bars 5 on the top, bottom, left and right, and are firmly fixed with tie bar nuts 6. Reference numeral 7 denotes a movable platen that is slidably fitted and supported by tie bars 5 near its four corners, and between this movable platen 7 and the link housing 3, two sets of upper and lower three-section toggle links 8 are extendable and retractable. connected. A mold clamping cylinder 9 for mold clamping is fixed horizontally to the link housing 3, and the working end of the piston rod 10 is connected to the center of the connecting member of the four-bar toggle link 11 that connects the three upper and lower toggle links 8. Fixed. The toggle links 8, 11, etc. constitute a toggle mechanism. 1
Reference numeral 2 denotes a guide shoe that guides the lower surface of the movable platen 7 by sliding it thereon. The fixed platen 4 and the movable platen 7 have a fixed mold 13 and a movable mold 1.
4 are mounted facing each other.

Toggle type mold clamping device 1 configured as above
When pressure oil is fed into the head chamber 15 of the mold clamping cylinder 9, the piston rod 10 moves forward and the movable platen 7, which is connected to it by toggle links 11 and 8, moves toward the fixed platen 4, thereby clamping the mold. It will be done. Also, when pressure oil is fed into the rod chamber 16 of the mold clamping cylinder 9, the piston rod 1
0 retreats, the movable platen 7 separates from the fixed platen 4, and the mold is opened.

In this toggle type mold clamping device 1, when the piston rod 10 of the mold clamping cylinder 9 reaches its forward limit during mold clamping, the toggle mechanisms 8, 11
The upper and lower toggle links 8 are fully extended straight, and a predetermined mold clamping force, such as 1000 TON, can be obtained. That is, the molds 13 and 14 are brought together when the piston rod 10 is, for example, about 100 to 200 mm before the forward limit and the toggle link 8 has not yet been fully extended (at this time, the tie bar 5 has not yet been fully extended and Therefore, if the piston rod 10 continues to move forward, the tie bar 5 will begin to extend as the link 8 extends, and the mold will be clamped according to the amount of extension of the tie bar 5. force is generated. At the final stage, the design is such that a predetermined mold clamping force can be obtained when the tie bars 5 are extended by 1 to 2 mm. At this time, the pressure P applied to the mold clamping cylinder 9 changes based on the characteristics of the toggle mechanism itself, drawing a curve as shown by the solid line in FIG.

FIG. 3 shows the mold clamping cylinder 9 during one molding cycle from the start of mold clamping to the completion of mold opening in the mold clamping device having the above-mentioned toggle mechanism.
It is a diagram showing the relationship between the stroke of the mold clamping cylinder 9 and the mold clamping cylinder internal pressure, in which the horizontal axis shows the stroke S of the mold clamping cylinder 9, the vertical axis shows the mold clamping cylinder internal pressure P, and the solid line shows the mold clamping cylinder internal pressure. The closing curve and the one-dot chain line indicate the mold opening curve. Further, FIG. 3 shows a stroke-pressure diagram in a normal state with no abnormalities anywhere. As is clear from FIG. 3, during the stroke x from the mold clamping start time O ₁ to the so-called mold matching time O ₂ where both molds 13 and 14 come into contact, the pressure fluctuates between pressure a and pressure b. However, almost the pressure B is maintained. Also, at the time of mold matching
After passing O ₂ , the pressure P rises to pressure C during the stroke x ₄ , and after the pressure drops, it rises again and ends the mold clamping at the mold clamping end point O ₃ .
At the time of mold opening, the pressure P drops rapidly from the starting point _O3 , and then the pressure rises slightly, and the mold opening is performed while maintaining almost the pressure d, and the mold opening is completed at the point _O4 where the pressure has increased.

[Problems to be Solved by the Present Invention] As mentioned above, the invention described in Japanese Patent Application Laid-Open No. 124063/1983 has a problem in which foreign objects are caught between the molds during the mold clamping operation of the direct pressure type mold clamping device. It is possible to detect whether or not there are any.

However, if there is no foreign matter caught between the molds, and there is a problem with the machine itself, such as a crack in the platen, tie bar or tie bar nut, or a loose tie bar nut, cannot be detected because no detection means is used for this purpose.

On the other hand, by extending this idea and detecting the timing of mold alignment during direct pressure type mold clamping operation,
It would be possible to invent a method to detect whether or not there is an abnormality in the machine itself.

However, when this idea is applied to a toggle-type mold clamping device, it is not possible to sufficiently detect abnormalities in the machine itself by detecting only one requirement, such as the timing during mold alignment. .
This is due to the structure of the toggle mechanism of the toggle type mold clamping device itself.

I will now explain why.

The change state of the pressure inside the mold clamping cylinder P over time T from the mold alignment time O ₂ to the mold clamping end time O ₃ when performing mold clamping operation using a toggle type mold clamping device is shown below. , which inevitably appears as shown in FIG. 1 due to the structure and operation of the toggle mechanism itself. That is, as mentioned above, after mold matching,
The pressure P rises to a rising pressure C, and after a moment the pressure drops, it rises again and reaches the maximum pressure, ending mold clamping.

In FIG. 1, the solid line _L4 indicates a normal pattern, and the one-dot chain line _L5 and dotted line _L6 indicate an abnormal pattern. That is, what is shown by the dashed line _L5 is the case where the rising pressure _C4 is smaller than the rising pressure C of the normal pattern _L4 , and what is shown by the dotted line _L6 is the case where the time _t6 required for rising is the normal pattern. This shows the case where it takes longer than the time t in the case of _L4 . In this case, if the rise characteristic, which is the degree of increase in pressure C per unit time t, is α, then
The rise characteristics α ₁ and α ₂ of the abnormal patterns L ₅ and L ₆ are both smaller than the rise characteristics α of the normal pattern L ₄ .

_L5 is a problem when the platens 4, 7, tie bars 5, or tie bar nuts 6 are cracked, the tie bar nuts 6 are loosened, or the toggle links 8, 11 are cracked.
This is the case when there is play in the toggle pin. In this case, since the mechanical member itself lacks rigidity, the rising pressure _C4 in the middle does not reach the desired pressure, and even if the piston rod 10 of the mold clamping cylinder 9 reaches its forward limit, the tie bar 5 will extend by a predetermined amount. Therefore, a predetermined mold clamping force cannot be obtained.

However, even if there is a mechanical abnormality, if the tie bar nut 6 is tightened a little more in advance, the length of the tie bar 5 between the fixed platen 4 and the link housing 3 will be shortened by that amount. It is possible to obtain a mold clamping force of but,
In this case, even if the rising pressure in the middle is C, the rising characteristics will be α ₂ <α, and the time required for rising will be longer, t ₆ >t.

Therefore, if only one of the three physical quantity values consisting of the rising pressure C, the time required for rising t, and the rising characteristic α is detected, it is not necessarily possible to accurately detect an abnormal state. Can not.

That is, as described above, if only the rising pressure C is detected among the rising pressure C, the time t required for rising, and the rising characteristic α, even if the rising pressure C is a predetermined value, the abnormal pattern L ₆ In addition, if only the time t required for the rise is detected, even if this time t ₅ is almost the same as the predetermined value t, an abnormal pattern such as L ₅ may be overlooked. There is a risk of overlooking the case. In addition,
When only the rise characteristic α is detected, even if the rise characteristic α is almost the same as the predetermined value α, the time t required for the rise may be Long, rising pressure C
There is a risk of overlooking the abnormal pattern in the case of foreign object entrapment, where the image appears slightly larger.

In addition, as mentioned above, the method of detecting the elongation of tie bars requires processing of variations in the detected values of the four tie bars, and since it is a mechanical measurement, malfunctions due to friction of the measuring rod, etc. occurs, making it difficult to expect satisfactory detection results.

[Means for Solving the Problems] In the present invention, in order to solve such problems, the toggle-type mold clamping device 1 is operated from mold alignment time O ₂ at the end of the mold clamping operation to mold clamping end time O ₃ . A pattern of changes in physical quantity values of normal oil pressure related specifications of the hydraulic cylinder drive unit for mold clamping is set, and this pattern is compared with the corresponding actual physical quantity values.In particular, rise pressure C, rise At least two physical quantity values are set among the time t required for the rise and the rise characteristic α representing the degree of pressure rise per time at rise, and these at least two physical quantity values are detected and compared to determine whether it is normal or abnormal. It is now possible to detect whether

[Function] In the present invention, at least two of the three physical quantity values of the rising pressure C in a normal state, the time t required for rising, and the rising characteristic α are set in advance, and at least two of these physical quantity values are set in advance. Detect and compare physical quantity values to detect differences, and check whether the rise pressure C actually detected is different from the corresponding physical quantity in a normal pattern, and whether the time t required for rise is If it is long or the rise characteristic α is small, it is detected that an abnormality has occurred in the mechanical part itself that constitutes the toggle type mold clamping device. The occurrence of an abnormality is then alerted by, for example, a buzzer or a lamp, so that the machine can be stopped and repairs can be made. Note that the rising pressure C is normally caused when the platens 4, 7, tie bars 5, or tie bar nuts 6 are about to crack, when the tie bar nuts 6 are loosened, or when the toggle pins of the toggle links 8, 11 are loose. When there is an abnormality, as in a certain case, it can be detected by the fact that the rising pressure C appears small, but conversely, when the rising pressure C appears large, the toggle pin part or the movable platen 7
It is possible to detect that the sliding resistance is increasing, or that a foreign object is caught between the clamped molds.

In this way, in the present invention, the platen 4,
Abnormalities in machine parts themselves such as 7 and tie bars 5 can be detected accurately and early, preventing major damage to parts and the accidents associated with this, and improving machine operation rate, safety, etc. It can be measured.

[Example] Next, the present invention will be explained in detail with reference to an example shown in the drawings.

Fig. 4 is a block diagram of the abnormality detection device for explaining the abnormality detection method, and Fig. 5 shows the stroke S of the mold clamping cylinder 9 and the internal pressure P of the mold clamping cylinder from the start of mold clamping to mold alignment. FIG. 2 is a relationship diagram showing a relationship between normal values and abnormal values; FIG.

In FIG. 4, an abnormality detection device 20 includes a pulse transmitter 21 that emits a pulse signal according to the normal pattern shown in FIG. The normal pattern here refers to the normal hydraulic pressure in the mold clamping cylinder, which is one of the hydraulic pressure-related specifications according to the stroke S of the mold clamping cylinder 9, which is the operation progress of the mold clamping device during the molding cycle. Refers to changes over time.
Reference numeral 22 denotes a memory that stores the signal input from the pulse generator 21, and is connected to the subtracter 23 through a signal circuit. A pressure sensor 24 that detects the pressure inside the hydraulic cylinder 9 is connected to the subtracter 23 via a signal circuit, and the signal from the pulse transmitter 21 and the signal from the pressure sensor 24 are subtracted to produce a signal proportional to the differential pressure. The voltage is input to a pair of window converters 25. In addition to the voltage from the subtracter 23, each window converter 25 has an upper limit voltage E ₁ and a lower limit voltage E ₂ as reference voltages.
are applied respectively, and when the voltage from the subtracter 23 is higher than the upper limit voltage _E1 or lower than the lower limit voltage _E2 , a signal is issued and the lamp 28 is turned on via the OR gate 26 and the driver 27. It is configured to sound a buzzer 29.

What is shown by a solid line _L1 in FIG. 5 is a normal pattern between strokes x in FIG. 3, and is stored in the memory 22. In addition, the dashed line L ₂ and the dotted line L ₃ indicate the movable platen 7, respectively.
The figure shows an abnormal pattern when the resistance of the sliding part is abnormally high. Now, for example, as shown by the dashed line _L2 , if the cylinder internal pressure P exceeds the allowable upper limit pressure _P0 and reaches _P1 , the difference from the normal pressure b, P-b, becomes the allowable difference. The pressure exceeds P ₀ −b. That is, the pressure _P1 detected by the pressure sensor 24 and the normal pressure signal b from the memory 22 are input to the subtracter 23, and the voltage corresponding to the differential pressure P-b is input to the window converter 25. . On the other hand, since the voltage E ₁ corresponding to the allowable upper limit differential pressure P ₀ −b is input to the window converter 25, even if the voltage E ₁ is
If P-b exceeds P ₀ -b even in times,
Wind converter 25 emits a signal and lamp 2
8 lights up and the buzzer 29 sounds, so abnormal overpressure inside the hydraulic cylinder 9 can be known. Usually, P ₀ is set to about 1.1 to 1.2b. Also,
Similarly, when the pressure P is unstable as shown by the dotted line, P-b becomes _P0 even once during the stroke _S3 .
If -b is exceeded, the abnormality detection device 20 is activated, so that it is possible to know whether the pressure is abnormal.
This is not limited to the case of mold clamping, but also in the case of mold opening, abnormal pressure can be detected and an alarm can be issued in the same manner. Furthermore, as is clear from FIG. 5, in the case of the normal pattern shown by the solid line _L1 , the pressure exceeds the allowable upper limit pressure _P0 after the stroke _S3 , whereas the dashed line _L2 and in the case of the abnormal pattern shown by the dotted line L ₃ , the stroke S ₁ or
Since P ₀ will be exceeded at S ₂ , the pressure P ₀
Stroke up to the pressure signal generated at S ₁ , S ₂
etc., and an alarm may be issued when this is smaller than the stroke _S3 of the normal pattern _L1 . In addition, in this case, the time to reach the allowable upper limit pressure P ₀ is faster in the abnormal patterns L ₂ and L ₃ than in the normal pattern L ₁ , so the time required to reach the allowable upper limit pressure P ₀ when actually detected is The time may be compared with the time required to reach P ₀ of the normal pattern L ₁ , and an alarm may be issued if the actually detected time is shorter than the time of the normal pattern L ₁ . The abnormal pattern L ₂ detected in this way,
The cause of L ₃ is thought to be galling between the movable platen 7 and tie bar 5, galling at the toggle pins that are the pivot points of the toggle links 8 and 11, or poor lubrication at these locations.
By removing these, a normal pattern can be obtained. In addition, if the above-mentioned actually detected time is longer than the time of normal pattern _L1 , an alarm can be issued.In this case, the hydraulic pressure rises slowly due to poor oil supply, so the hydraulic pump or hydraulic piping failures. Furthermore, in the case of galling or poor lubrication of the sliding parts,
Since the amount of oil supplied from the hydraulic pump per unit time or per unit stroke is greater than in the case of a normal pattern, an abnormality may be discovered by detecting an excessive amount of supplied oil.

Figure 1 is a time-frame for explaining the main parts of the present invention.
A line that is a pressure diagram and shows the relationship between the mold clamping time T and mold clamping cylinder internal pressure P between a normal value and an abnormal value from the mold matching time O ₂ to the mold clamping completion time O ₃ It is a diagram.

As described above, in FIG. 1, the pattern shown by the solid line _L4 is a normal pattern, and the pattern shown by the chain line _L5 and dotted line _L6 is an abnormal pattern.
That is, what is shown by the chain line _L5 is the case where the pressure _C4 is smaller than the pressure C of the normal pattern _L4 ,
Also, what is indicated by the dotted line L ₆ is the time required for rising t ₆
This shows a case where it takes longer than the time t for the normal pattern _L4 . In this case, the abnormal pattern
The rising characteristics α ₁ and α ₂ of L ₅ and L ₆ are both smaller than the rising characteristic α of the normal pattern L ₄ .

Therefore, in order to detect an abnormality in such a state, the rising pressure C of the normal pattern _L4 ,
The values of at least two physical quantities of the time t required for rising and the rising characteristic α are stored in advance, and these, the rising pressure C ₄ actually detected by measurement during the mold clamping operation, and the rising Compare at least two physical quantity values corresponding to the set value among the required time _t6 , rise characteristics _α1 , _α2, etc., and check whether there is a difference in the actually detected rise pressure _C4 . Is the time _t6 required for the rise long?
An abnormal signal is transmitted when the rise characteristics α ₁ and α ₂ are small. Note that the set physical quantity value of the normal pattern _L4 may have a certain range as described above.

In addition, in the case of normal pattern _L4 , due to the structure of the toggle mechanism, the time t required for rising appears as a minimum value, and the rising characteristic α appears as a maximum value, so if the rising time t is long or the rising characteristic α It can be judged as abnormal only if the value is small. However, regarding the rising pressure C, normally,
If the rising pressure C is small, it can be assumed that there is an abnormality in the mechanical parts, such as a crack in the platens 4, 7, tie bar 5, or tie bar nut 6, or a loose tie bar nut 6, but it is safe to assume that there is a problem with the movable platen 7 or the toggle pin. When the sliding resistance of the parts increases, the rising pressure C may appear slightly larger than the standard value C.Also, even if there is no abnormality in the mechanical parts, foreign objects may be inserted between the clamped molds. When clamping, the rise characteristic α is the reference value α
However, this rise pressure C appears as a larger value than the reference value C, and the rise time t also appears large, so if the rise pressure C is too large, it may be an abnormality due to the sliding part or foreign matter getting caught. It is necessary to judge. Therefore, regarding the rising pressure C, it is necessary to judge whether it is normal or abnormal depending on whether there is a difference from the reference value. However, even if abnormalities in the sliding parts are not specifically detected at this stage, they can be sufficiently and easily detected before mold matching, as shown in FIG.

In the case of the rise characteristic α, the pressure rise is differentiated with respect to time to obtain α using dP/dt=α, and an abnormal signal can be transmitted by comparing α ₁ and α ₂ in this case with α. This can also be done by detecting when the pressure rises. That is, a certain characteristic β is set and a signal is emitted when dP/dt≦β, or a signal is emitted when P ₀ =1.1 to 1.2b. Next, after emitting a signal at the upper limit of the pressure, a signal is emitted again when dP/dt=0. Detect the time during this time and the pressure C ₄ when dP/dt = 0, and compare α of the normal pattern with the actually measured α ₁ and α ₂ as C ₄ −b/t = α. , an abnormality can be known by issuing an abnormality signal to generate an alarm.

As mentioned above, in FIG. 1, L ₅ indicates that if there is a crack in the platens 4, 7, tie bar 5, or tie bar nut 6, if the tie bar nut 6 is loose, or if there is play in the toggle pins of the toggle links 8, 11. It is. In this case, since the mechanical member itself lacks rigidity, the rising pressure _C4 in the middle does not reach the desired pressure, and even if the piston rod 10 of the mold clamping cylinder 9 reaches its forward limit, the tie bar 5 will extend by a predetermined amount. Therefore, a predetermined mold clamping force cannot be obtained.

However, even if there is a mechanical abnormality, if the tie bar nut 6 is tightened a little more in advance, the length of the tie bar 5 between the fixed platen 4 and the link housing 3 will be shortened by that amount. It is possible to obtain the desired mold clamping force. but,
In this case, even if the rising pressure in the middle is C, the rising characteristic becomes α ₂ <α, and the time required for rising becomes longer, t ₆ >t.

Therefore, as mentioned above, detecting only one of the three physical quantity values consisting of the rising pressure C, the time required for rising, t, and the rising characteristic α does not necessarily accurately identify the abnormal state. cannot be detected.

However, in the present invention, as described above, at least two of the physical quantity values of the actual hydraulic pressure-related specifications of the mold clamping cylinder drive unit, which are the rising pressure C, the time t required for rising, and the rising characteristic α, are By knowing the changes, you can easily know whether the mechanical parts themselves are normal or abnormal.

The reason why the rise characteristics for mold clamping are abnormal is that the rigid parts that take charge of the reaction force when mold clamping force is generated, namely the fixed platen 4,
It is conceivable that a crack may have occurred in the tie bar 5, platens 4, 7, etc., and by inspecting these and removing the cause, a normal pattern _L4 can be obtained.

In addition, in each of the above embodiments, the molds 13, 1
Since the reference value changes depending on the thickness of mold 4, it is necessary to provide a coefficient for the mold thickness.

[Effects of the Invention] As is clear from the above explanation, according to the present invention, as a method for detecting an abnormality in a mold clamping device for a molding machine,
A physical quantity value pattern L ₄ of the normal hydraulic pressure related specifications of the mold clamping drive unit from the mold matching point O ₂ to the mold clamping end point O ₃ of the molding cycle is set.
This pattern _L4 is compared with the corresponding actual physical quantity value pattern, and in particular, the rise pressure C after die matching in both patterns, the time t required for rise, and the pressure per time during rise. At least two physical quantity values of the rising characteristic α representing the degree of rise are set, detected, and compared to detect a difference, and for the corresponding physical quantity values C, t, α in the normal pattern _L4 , If the rising pressure C has a difference, the time t required for rising is long, or the rising characteristic α is small,
By configuring the toggle type mold clamping device 1 to detect abnormalities in the mechanical parts themselves, cracks in the platens 4, 7, tie bars 5, tie bar nuts 6, etc., loosening of the tie bar nuts 6, and toggle links can be detected. Since play in the toggle pins of parts 8 and 11 can be detected early, it is possible to prevent major damage that would make the parts unusable, reducing costs and improving machine operating rates. At the same time, it is possible to prevent major accidents due to major damage to parts, etc., and safety is significantly improved.

[Brief explanation of drawings]

Figure 1 is for explaining the main part of the present invention, and compares the relationship between the mold clamping time and the internal pressure of the mold clamping cylinder from the time of mold matching to the completion of mold clamping between normal and abnormal values. FIG. 2 is a schematic diagram showing one embodiment of the toggle type mold clamping device for a molding machine according to the present invention, and FIG. 3 is a diagram showing the stroke of the clamping cylinder and the internal pressure of the clamping cylinder. Figure 4 is a block diagram of the abnormality detection device, and Figure 5 is a diagram showing the relationship between the stroke of the clamping cylinder and the internal pressure of the clamping cylinder from the start of mold clamping to mold alignment. A diagram showing a comparison between normal values and abnormal values, and FIG. 6 is a diagram showing the relationship between the stroke of the mold clamping cylinder and the internal pressure of the mold clamping cylinder, showing an example of a conventional method similar to the present invention. be. 1... Toggle type mold clamping device, 3... Link housing, 4... Fixed platen, 5... Tie bar,
6... Tie bar nut, 7... Movable platen,
8, 11...Toggle link (toggle mechanism),
9...Mold clamping cylinder, 13...Fixed mold, 14...
...Movable mold, 20... Abnormality detection device, O ₁ ... At the start of mold clamping, O ₂ ... At the time of mold alignment, O ₃ ... At the end of mold clamping, P... Pressure inside the mold clamping cylinder, S... Mold clamping stroke, T...Mold clamping time, C...Rise pressure, t...Time required for rise, α...Rise characteristic.

Claims (1)

[Scope of Claims] 1. An abnormality detection method in a toggle-type mold clamping device 1 for a molding machine in which a movable mold 14 is moved by a mold clamping cylinder 9 via toggle mechanisms 8 and 11 to open the mold. , Store and set the pattern of changes in physical quantity values of the normal oil pressure related specifications of the mold clamping cylinder 9 drive part from at least the mold alignment time O ₂ to the mold clamping end time O ₃ during mold clamping, and correspond to this pattern. Detect the pattern of changes in physical quantity values of hydraulic pressure-related specifications during the actual mold clamping operation, and detect the rising pressure C after mold alignment, the time t required for rising, and the pressure rise per hour during rising in both patterns. Of the rise characteristic α that represents the degree of
Compare at least two physical quantity values to detect a difference, and check whether the rising pressure C actually detected has a difference with respect to the corresponding physical quantity values in a normal pattern, or the time t required for rising. A method for detecting an abnormality in a toggle-type mold clamping device for a molding machine, which detects that an abnormality has occurred in the mechanical part itself that constitutes the toggle-type mold clamping device when is long or the rise characteristic α is small.