JPS59107761A - Method for discriminating degree of galling in injection plunger mechanism - Google Patents

Abstract

PURPOSE:To discriminate the danger of the degree of galling in an injection plunger mechanism by measuring the liquid pressure in an operating cylinder which operates an injection plunger and the differentiated value of the liquid pressure. CONSTITUTION:The liquid pressure in an operating cylinder 15 of an injection plunger is detected with a pickup element 21 of a pressure detector, is amplified by an amplifier 22 and is fed to the 1st comparator 25. Said pressure value is also fed, via a differentiation circuit 23 to the 2nd comparator 26. The 1st comparator 25 outputs the 1st output signal when the liquid pressure in the cylinder 15 is at a prescribed value or above and the 2nd comparator 26 outputs the 2nd output signal when the change in the liquid pressure in the cylinder 15 is sharp, that is, when the operation of the cylinder is stuck. The injection distance until the galling of the plunger arises is detected in the 1st latching counter 36 and the injection distance until the galling ends is detected in the 2nd latching counter 37. An arithmetic circuit 41 calculates the extent of movement only from the galling state of the plunger tip from both signals from the counters 36, 37 and transmits the same to the 3rd comparator 45. The comparator 45 actuates an alarm system 48 when said signal attains the value set by a setter 46 or above.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting force on a chip in a sleeve in a molten metal injection granulator used in a die casting machine.

In die casting molding, as shown in Fig. g1, when forming a product with molten metal in the cavity 18, the molten metal is first injected into the injection sleeve 12, and then the granger tip 13 provided in the injection sleeve Die casting is performed by advancing the molten metal in the sleeve into the cavity by moving it forward under high pressure and at low and high speeds.

By the way, due to incorrect installation of the die-casting machine or vibration during operation, the positional relationship between the injection sleeve and the plunger tip may be eccentric, or the lubricant may be insufficient.
Or, if the die-casting machine 10 is operated for a long time, the granular tip 13 may wear out, or solidified metal particles may adhere or exist within the injection sleeve, causing the granular tip 13 and the inner wall of the injection sleeve 12 to become loose. This may cause what is called galling.

When such galling occurs, the granger tip cannot perform normal injection operation.

Since the predetermined and stable injection speed is not achieved, the so-called injection granger will operate in a state-like manner with jerks, causing the molten metal in the injection tube to ripple greatly during injection, causing a drop in molten metal temperature. This may cause deterioration of the molten metal, or may cause air to be entrained in the molten metal, which may cause various defects such as deterioration of the molten metal, formation of cavities in the finished product, or failure to meet the specified strength of the finished product. Become.

Therefore, the galling that causes this defect can be detected early,
Maintenance of Grand Soya Tigs and injection sleeves is very important in order to produce high-quality die-cast products, prevent damage to the casting mechanism, and also to ensure the safety of die-cast machine operators. This is a. Therefore, there have conventionally been various galling detection methods.

Conventional detection methods include, for example, measuring the amount of fluid pressure in the driving fluid circuit of the granger mechanism when the plunger tip is retracted or ejected (approximately equivalent to the movement resistance of the plunger tip),
There are methods of measuring the amount of change in the hydraulic pressure (hydraulic pressure differential amount) to detect galling, but in all of these methods, galling is determined only based on one measured amount.

This 21. In these detection methods, 1. How long does the galling state continue within the sleeve? Or, if the plunger tip moves in a galling state, there is a problem in determining the degree of risk of galling (a force that exhibits a stick-like movement phenomenon), or if there is actually no force delta galling phenomenon, at the time of speed change There were drawbacks in making accurate measurements, such as detecting the generated surge pressure as the occurrence of shear.

The present invention eliminates the drawbacks of the conventional galling detection method and measures the hydraulic pressure of the operating cylinder of the driving hydraulic circuit of the injection grunger, thereby determining the magnitude of resistance between the injection sleeve and the plunger tip. By measuring the magnitude of galling and the differential amount of the hydraulic pressure, it is possible to grasp the progress of galling or 7)) stick phenomenon behavior of the plunger tip due to the progress of galling, and furthermore, to determine abnormal hydraulic pressure. This invention relates to a method of determining the degree of risk of galling by measuring the length of a continuous value.

That is, the method according to the invention includes an operating cylinder 15 for actuating an injection grunger 11 containing a plunger tip 13.
The hydraulic pressure and the differential value of the hydraulic pressure are measured, and this hydraulic fine molecule ~
If this happens, measure the injection stroke or travel time of the injection plunger when the fluid pressure continues to exceed a predetermined value, and check the risk of galling of the injection granger mechanism. This is a method for determining the galling position of a die-cast injection granger mechanism.

That is, a specific example of the method related to Kinoe F3A is shown in FIG.
As shown in the figure, when the operating cylinder 15 of the injection granger is sent to the comparator section, it is also sent to the second comparator section via the differentiating circuit 23.

By the way, the first comparator 25 is set by a second setting device for setting an abnormal value of hydraulic pressure.
When the pressure signal voltage is higher than the predetermined voltage, that is, when the operating cylinder 15
This is a comparator section that emits a gl output signal when the hydraulic pressure of the gl reaches a predetermined value or higher.

The second comparator 26 uses a predetermined voltage set by the second setting device measurement for setting the abnormal galling progress value and the differentiating circuit 23.
It compares the differential signal detected in error and issues a second output signal when the differential signal exceeds a predetermined value, that is, when the hydraulic pressure change of the operating cylinder 15 is a sudden change greater than a predetermined value, that is, when the stick-like movement occurs. This is comparator 3.

Further, both the first output signal and the second output signal described above are input to the first AND circuit 31, and the 41 output signal from the first comparator 5 is input to one terminal of the second AND circuit 32 as a negative input. .

Further, the output from the first AND circuit 31 is inputted to the other terminal of the second AND circuit 32 via the monostable multivibrator 33, and the output of the second AND element 32 is input as a latch signal of the il latch counter 36. A pulse signal corresponding to the granger position from the position detection pulse generator 35'iJ) of the injection granzer 3 is input to the input granjar 3.

The il latch counter 36 is connected to the first AND element 31.
7)) When there is a latch signal input from the above, the plunger position signal at that time is held in the first latch counter 36, and at the same time, the value is transmitted to the arithmetic circuit 41, and the second latch counter n is input from the second AND element 32. When a latch signal is input, the plunger position signal at that time is held in the second latch counter 37, and at the same time, the value is transmitted to the arithmetic circuit 41.

T7. C, the lth latch counter detects the ejection distance from the start of the grunge until galling occurs, and the second latch counter r detects the ejection distance from the start of the grunge until the end of the force.

Therefore, the arithmetic circuit 41 consists of 36 gl latch counters)
When receiving the signal sent from the second ratuna counter 37 and the signal sent from the second ratuna counter 37, the amount of movement is calculated based on only the galling state of the plunger tip 13 in the injection lunge 11 from both signals, and a signal is sent to the third comparator tsu. If the signal from the third comparator 45 causes the amount of movement of the plunger tip B to exceed the set value set by the third setting device 46 as the amount of movement only in the galling state, the alarm system is activated. let It goes without saying that the alarm system may include any number of features such as lamps, alarms, text displays, etc.

The operation of the above embodiment will be described in detail below.

Cylinder operating pressure P (responsive to the pressure signal V of the sieve
With P as the vertical axis, when the plunger tip 13 travels over time and the injection gransha 11 is activated, a surge pressure P1 is instantaneously generated at startup, and a signal value VP1 corresponding to a predetermined pressure is generated.
It occurs over the Soviet Union. Next, the pressure stabilizes at a predetermined pressure ps, but the peak pressure P may be lowered due to a small amount of force or vibration of the machine that does not adversely affect the product.
2 Furthermore, due to increased friction between the plunger tip 13 and the circular surface of the injection sleeve 12, various pressure fluctuations occur due to peak pressure and large galling (peak pressure) that affects the product. There are cases. Therefore, the voltage V input to the first comparator 25 in response to the predetermined pressure PS f
P, the voltage VP2 corresponding to the set pressure PK higher than
If n is generated by a setter n and is used as a reference signal to the l-th comparator O, the l-th comparator 5 will generate a pressure signal voltage when the input from the amplifier 22 is higher than the reference signal '148Ev'pλ. The lth output signal is emitted at 6 degrees, so if the operation range is exceeded, that is, up to the passes p, , tK, and tS in Figure 3.
, from tE2 to tE2 and from tS to tEJ, the first output signal is generated from the first comparator 25? I will do it.

Further, the pressure release signal VP fi is differentiated by a differentiating circuit, and a rate of change ζ (signal voltage) of the pressure signal is generated.

Therefore, if the predetermined voltage △VP/ is set by the second setter command, if the change in fluid pressure is severe (t's, ,
t's.

The second comparator outputs a second output signal at t's, t's, ).

Therefore, the Ml AND circuit 31 to which the lth output signal and the second output signal are inputted is used when the signal Δvp corresponding to the change rate t of the hydraulic pressure to the operation cylinder 15 is abrupt, that is, as shown in FIG. A latch signal is output to the tS, tltP field of the first
Latch counter Latch that data.

As described above, when the output signal of the amplifier circuit is equal to or higher than VP, that is, the hydraulic pressure is equal to or higher than the predetermined value PK, and the rate of increase is rapid, the first AND circuit 31 issues a latch signal, and the injection plunger 11 The position signal is latched as data T, that is, the abnormal pressure generation position, and the position data is sent to the arithmetic circuit 41.

On the other hand, the monostable multivibrator 33 is activated by the trigger signal from the first AND circuit 31, and the second AND circuit 32 receives the output pulse signal from the monostable multivibrator.
receives the pulse signal as an input and also takes in the first output signal of the first comparator section as a negative input. Therefore,
The second AND circuit 32 receives the pulse signal, and
When the first output signal disappears, Tf, that is, when the hydraulic pressure of the operating cylinder 15 drops below the abnormal high pressure level PK (
It generates an output at tE7+'' and sends a latching signal to the second latch counter 37.

The second latch counter J is connected to the second AND circuit 32 as described above.
When a latch signal is received from the second latch counter η, the granger position data from the position detection pulse is latched into the second latch counter η, and the data is sent to the arithmetic circuit 41. The arithmetic circuit 41 receives from the first latch counter a grandshaft position signal when the hydraulic pressure of the operation cylinder 15 undergoes a sudden change of more than a predetermined value and becomes a pressure of more than a predetermined high pressure PK. The second position signal 11 is then received.

Therefore, by calculating the position data from the arithmetic circuit 4N iron Ml latch counter and the position data from the second latch counter, the hydraulic pressure of the operating cylinder 15 can be made equal to or higher than the differential value of the hydraulic pressure, and the hydraulic pressure is continuously maintained. An injection stroke that is a predetermined value is calculated.

The third step determines whether this calculated stroke is less than or equal to a predetermined value.
The comparator 451 detects the stroke, and if the stroke is equal to or greater than a predetermined value, the alarm system 48 is activated to issue an alarm or to stop the operation of the operating cylinder 15.

Incidentally, the fact that the consecutive strokes of abnormally high pressure exceed a predetermined value is the same as that the continuous time of abnormally high pressure exceeds a predetermined value. Therefore, as shown in FIG. The output signal from the AND circuit 32 and the output signal from the second AND circuit 32 are directly led to the timer measurement circuit company, and the time difference between the output signal and the first AND circuit 32 is measured. After receiving the signal from the AND circuit 31, the alarm system 48 is activated if the signal from the second AND circuit 32 is not received within a predetermined period of time.

In addition, the above measurement is performed simply by inputting an input signal that measures the stroke or time during which the hydraulic pressure continuously exceeds the predetermined value PK when the hydraulic pressure and the hydraulic pressure differential value exceed a predetermined value IS. 31 is measured, and when the hydraulic pressure and the hydraulic pressure differential value exceed a predetermined value, the time period during which the hydraulic pressure differential value continuously exceeds a predetermined value △vp may be measured. .

This measurement is a method that can detect when a sudden pressure increase continues for a longer time after the fluid pressure exceeds a predetermined value PK, and it can be detected that the injection lunge's sieve IJ 79"15 becomes dangerously high pressure due to galling. It is possible.

As described above, when the hydraulic pressure and the differential value of the hydraulic pressure exceed a predetermined value, the method according to the present invention is used to prevent injection strokes in which the hydraulic pressure or the differential value of the hydraulic pressure continuously exceeds the predetermined value. Alternatively, this is a method of measuring the travel time of the injection grunger, and since it is activated when the differential value is greater than a predetermined value, the fluid pressure of the operating cylinder 15 changes gradually (P in α in Fig. 3), which does not adversely affect the die-cast product. Because it measures when the fluid pressure continuously exceeds a predetermined level, even if the fluid pressure becomes abnormally high, it can be used for die-cast products (for an extremely short period of time without any negative effects). This is a method that excludes changes in fluid pressure (P in Figure 3a) and determines the degree of galling by detecting a sudden change in fluid pressure that causes abnormally high pressure to persist above a predetermined level, or by detecting dangerous abnormally high pressure. be.

Therefore, galling, which has a negative impact on die-cast products, can be accurately detected, and the injection speed and pressure at the time of injection may become unstable.
We require measures to prevent the occurrence of molten metal waving, gas entrainment, and drop in molten metal temperature within the injection sleeve, improve the flow of the molten metal in the cavity, prevent the occurrence of cavities in the product, and ensure high quality die casting. This means that the company will be able to manufacture products.

The method of the present invention (method for determining the degree of galling) is used when measuring galling during forward movement or retraction without injecting molten metal into the sleeve 12, or when measuring galling during forward movement or retraction, or when measuring galling during forward movement or retreat. When performing measurement discrimination at the time of injection (this is a discrimination method that can be carried out), measurement under no load (measurement under no load) is a method that can be used to determine whether the granger chip It is possible to accurately measure the condition with respect to the inside of the sleeve, and on the other hand, actual firing measurements can accurately determine the movement of the plunger tip during actual operation.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a tie casting machine, Fig. 2 is an example of a circuit implementing the present invention, Fig. 3 is a diagram showing changes in hydraulic pressure of the operating cylinder, etc., and Fig. 4 is another circuit for implementing the invention. This is an example. 10 = 9" squid casting machine, 11 - injection plunger, 12 = sleeve, 13 = plunger tip, 15 two operating cylinders, 18 = cavity, 21 = pick-up element, 22 = amplifier, 23 = differentiator, compared to 25.2 27, two-pronged regulator, 31.32=AND element, 33=multivibrator, 35=position pulse generator, 3ζ37 niratsuchi counter, 41=arithmetic circuit,
42 = timer 1 measurement circuit, 45 = comparator, 46 2 setting device, 48 2 glance report system. Patent Applicant Ube Industries Co., Ltd. Agent Patent Attorney Seizo Kitamura Pny'-] Other 2゛Name

Claims (1)

[Claims] The hydraulic pressure of the operating cylinder during movement of the injection plunger mechanism and the differential value of this hydraulic pressure are measured, and if both this hydraulic pressure and the hydraulic pressure differential value exceed a predetermined value, then the hydraulic pressure is Measure the injection stroke length or the travel time of the injection granger when it appears above a predetermined value continuously, and determine the danger of galling of the injection granger mechanism. How to determine prescription.