JPH0538742A - Molding condition setting method of injection molder - Google Patents

Abstract

PURPOSE:To obtain injection-molded article having stable weight, appearance and the like by a method wherein filling rate, metered value, dwelling pressure and the like are set by directly detecting the behavior of the resin in a mold through the observation of the changing state per shot of the propagation velocity of ultrasonic wave in the resin. CONSTITUTION:At the mold 1, which has a cavity 13 hating an inner surface shape corresponding to the outer surface shape of a product between a fixed mold 11 and a movable mold 12, of an injection molder, an untrasonic probe 2 is provided on the outside surface of the fixed mold 11. The probe 2 is attached in an attaching part 21 through contacting substance such as glycerin or the like at the position, from which the probe can transmit ultrasonic wave to nearly middle position between the terminal of a sprue 14 and the terminal of the cavity 13. In an ultrasonic measuring instrument 3 connected with the probe 2, on the basis of the changing state of propagation velocity per shot, the optimum molding conditions of the filling rate, metered value and dwelling pressure or dwelling time are grasped and displayed on a display 4 and, at the same time, the optimum molding conditions are set in the injection molder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for setting molding conditions such as optimum filling speed, measured value, holding pressure, holding time and cooling time in an injection molding machine.

[0002]

2. Description of the Related Art Conventionally, in order to obtain the best molding condition for stabilizing the weight of injection-molded products and making the appearance of products uniform, the weight and appearance of injection-molded products must be checked on the site side. I was relying on the unique technology of setting appropriate molding conditions.

[0003] These unique techniques are not necessarily the best stable molding conditions such as weight and appearance of injection molded products, and there is a problem that defective products are generated and loss is large.

In view of this problem, however, the behavior of the resin in the mold is observed by utilizing the reflected waves of the ultrasonic waves transmitted toward the resin in the mold, and this is used to set the molding conditions. Proposals have been made.

For example, Japanese Patent Application Laid-Open No. 60-247511 discloses a method of detecting the temperature and behavior of plastic in a mold by using ultrasonic waves.
No. 61 discloses a method of detecting a solidified state of a solidified product by ultrasonic waves, and Japanese Patent Laid-Open No. 3-61018 discloses a speed change of ultrasonic waves transmitted toward a resin in a gate in a mold. Alternatively, a method of comparing the amplitude change with a set condition and releasing the holding pressure when the set condition is reached is described. Japanese Patent Laid-Open No. 3-110116 discloses a method of transmitting an ultrasonic wave toward a resin in a mold. A method is described in which the measured value of speed change is compared with a preset value obtained at the time of molding a non-defective product and the time when the preset value is reached is set as the cooling time.
Japanese Patent No. 10117 discloses a method of comparing a speed change of an ultrasonic wave transmitted toward a resin in a gate in a mold with a set speed value at the time of molding a good product and setting a time point when the set speed is reached as a holding pressure time. Have been described.

[0006]

However, in any of the conventional methods described in the above publications, ultrasonic waves are emitted toward the resin in the mold and compared with the set value obtained at the time of molding a good product. Is adopted. The set value at the time of molding the non-defective product is determined by a unique technique of judging the weight, appearance, etc. of the injection molded product, and there is a problem that the set value itself cannot be said to be the optimum molding condition.

The present invention has been made in order to solve the above-mentioned conventional problems, and the purpose of the present invention is to consider the weight, appearance, etc. of an injection-molded article to determine the conventional specific technique. By observing the change state of the propagation velocity of the ultrasonic wave passing through the resin without deciding by, the behavior of the resin in the mold can be directly detected and the optimal molding conditions without burrs and pressure shortage can be grasped. By setting the optimum molding conditions in an injection molding machine, it is an object to manufacture an injection molded product with stable weight and appearance.

[0008]

According to the invention of claim 1 of the present application, in an injection molding machine equipped with an injection molding die provided with a cavity for forming a molded product, ultrasonic waves are transmitted into the die, Molding conditions such as the filling speed of the resin filling the cavity, the measured value, the holding pressure or the holding time while continuously detecting the time of the reflected wave that passes through the resin inside the cavity and is reflected By observing the change state of the propagation velocity for each shot by changing the
This is a method for setting molding conditions for an injection molding machine, in which optimum molding conditions such as a measured value, a holding pressure or a holding time are grasped and the optimum molding conditions are set in an injection molding machine.

According to the invention of claim 2 of the present application, an operation of grasping the optimum molding conditions of the filling speed, the measured value, the holding pressure and the holding time of the first aspect and setting the optimum molding conditions in the injection molding machine is performed. This is a method for setting the molding conditions of the injection molding machine, which is performed in this order and finally sets all of these optimum molding conditions in the injection molding machine.

According to the invention of claim 3 of the present application, in an injection molding machine equipped with an injection molding die having a sprue communicating with a cavity for forming a molded product, ultrasonic waves are transmitted into the die to generate an ultrasonic wave. While continuously detecting the reflected wave time that passes through the resin and converts it to the propagation velocity, observe the change state of the propagation velocity of one shot that gives sufficient cooling time for the resin filled in the sprue, This is a molding condition setting method for an injection molding machine, characterized in that a time point when a propagation velocity corresponding to a cooling time becomes a constant value is grasped as an optimum cooling time, and the optimum cooling time is set in an injection molding machine.

In the present invention, the propagation velocity means the velocity of ultrasonic waves passing through the resin filled in the mold, but in the following description, the propagation velocity is represented by the following formula 1. The ultrasonic wave passes through the resin at a propagation speed shown by 2), that is, twice the thickness D of the resin-filled portion of the resin filled with the ultrasonic wave (the distance that the ultrasonic wave travels back and forth). The explanation will be given by applying the time divided by the time T.

Propagation speed = thickness D (constant) of the resin-filled portion of the mold filled with the resin through which ultrasonic waves pass × 2 / T ...
Formula 1 The thickness D of the resin-filled portion of the mold filled with the resin through which the ultrasonic waves pass means, for example, when the resin filled in the cavity is targeted, the portion of the cavity filled with the resin. When the resin filled in the sprue is targeted, it means the thickness of the portion of the sprue filled with the resin.

The time T required for the ultrasonic wave to pass through the resin is defined as the time required for the ultrasonic wave to pass through the resin, and the boundary surface between the mold surface and the resin does not pass through the resin filled in the mold after the ultrasonic wave is transmitted. The time t ₁ required to detect the primary reflected wave reflected from the mold and the primary reflected wave reflected from the boundary surface between the resin and the mold surface after passing through the resin filled in the mold from the time when the ultrasonic wave is transmitted. Difference from the time t ₂ required to detect
Apply t ₂ −t ₁ .

[0014]

According to the molding condition setting method for an injection molding machine of the first aspect of the present invention, ultrasonic waves are transmitted into the mold and the time of the reflected wave reflected by the resin in the cavity is continuously detected. While changing the filling speed of the resin to be filled in the cavity, the measured value, the holding pressure or the holding time, the change state of the propagation speed for each shot is observed while converting into the propagation speed. By grasping the optimum molding conditions such as filling speed, measured value, holding pressure or holding time, and setting these optimum molding conditions in the injection molding machine, while directly detecting the behavior of the resin in the mold. Ascertain the optimum molding conditions such as filling speed, measured value, holding pressure or holding time as the basic conditions for manufacturing stable injection molded products such as weight and appearance, and then injection molding the optimum molding conditions. Machine can be set.

According to a second aspect of the present invention, there is provided a method for setting a molding condition for an injection molding machine, which comprises grasping the optimum molding condition of the filling speed, the measured value, the holding pressure and the holding time and the optimum molding condition. Perform the operation to set the injection molding machine in this order,
Finally, by setting all of these optimum molding conditions in the injection molding machine, the behavior of the resin in the mold is directly detected, and finally the filling speed, measured value, and holding pressure without burrs or pressure shortages. By setting the optimum molding conditions for pressure and holding time,
It is possible to manufacture an injection-molded product with stable weight and appearance.

According to the molding condition setting method of the injection molding machine of the third aspect of the present invention, ultrasonic waves are transmitted into the mold and the time of the reflected wave reflected by passing through the resin in the sprue is continuously detected. The propagation time of the resin filled in the sprue is converted into the propagation speed, and the change state of the propagation speed of one shot is observed. By setting the optimum cooling time in the injection molding machine, it is possible to directly detect the behavior of the resin in the mold and to establish the basic conditions for manufacturing an injection molded product with stable weight and appearance. The optimum molding conditions for the cooling time can be grasped and the optimum molding conditions can be set in the injection molding machine.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a portion of a mold 1 in an injection molding machine applied to the embodiments of the inventions of claims 1 and 2 of the present application.

The mold 1 includes a fixed mold 11 provided with a sprue 14 and a movable mold 12, and a cavity 13 having an inner surface shape corresponding to an outer surface shape of a product to be molded. There is. The movable die 12 is reciprocally movable by the hydraulic cylinder 5 in the arrow direction in the drawing.

An ultrasonic probe 2 is provided on the outer surface of the fixed mold 11. The ultrasonic probe 2 has a sprue 14
To a mounting portion 21 provided at a position where ultrasonic waves can be transmitted toward the middle of the end of the cavity 13 and the end of the cavity 13 via a contact substance such as glycerin on the mounting surface.

An ultrasonic measuring device 3 is connected to the ultrasonic probe 2. The ultrasonic measuring device 3 is, for example, 0.001 to
A transmission wave of 5 MHz is transmitted every second and the reflected wave is measured.

In addition, the ultrasonic measuring device 3 receives the resin in the cavity 13 in one cycle of molding based on the primary reflected wave which is received by the ultrasonic probe 2 and is reflected inside the cavity 13. A detection means (not shown) for detecting the behavior at any time is provided, and this detection means is configured by software. The output of the ultrasonic measuring device 3 is displayed on the display device 4.

FIG. 2 shows a part of a mold 6 in an injection molding machine applied to the embodiment of the invention of claim 3 of the present application. The difference from the part of the mold 1 shown in FIG. 1 is that the ultrasonic probe 2 is attached to the attachment portion 21 so that the ultrasonic probe 2 can emit ultrasonic waves toward the vicinity of the inlet of the sprue 14, and the attachment surface is made of a contact substance such as glycerin. It is the point attached via. Since the other points are the same as those shown in FIG. 1, only corresponding reference numerals are given in FIG. 2 and the description thereof is omitted.

Next, an embodiment of the invention of claims 1 and 2 of the present application using the mold 1 will be described with reference to FIG. In FIG. 1, first, a resin is injected into the cavity 13 of the mold 1 by an injection molding machine, so that the resin is injected in the cavity 13 in one cycle of filling, holding pressure switching, holding pressure / metering, and cooling. Go through the process. During this time,
An ultrasonic wave is transmitted from the ultrasonic probe 2 into the die 1 by the ultrasonic measuring device 3 every 0.001 to 1 second. It is reflected by the boundary surface 111 between the resin filled in the cavity 13 and the fixed mold 11 and the boundary surface 121 of the moving mold 12, and the primary reflected wave and the secondary reflected wave thereof are transmitted again through the fixed mold 11 and are superposed. It is measured by the ultrasonic measuring device 3 via the ultrasonic probe 2.

FIG. 3 shows the waveforms of the transmitted wave and the reflected wave. In FIG. 3, a shows the waveform of the transmitted wave. b ₁ and b ₂ show the waveforms of the primary reflected wave and the secondary reflected wave reflected from the boundary surface 111 between the resin filled in the cavity 13 and the fixed mold 11, respectively. c ₁ and c ₂ are the resin filled in the cavity 13 and the moving mold 1, respectively.
2 shows the waveforms of the primary reflected wave and the secondary reflected wave reflected by the boundary surface 121 of No. 2. Normally, the ultrasonic probe 2 to the cavity 1
Boundary surface 111 between the resin filled in 3 and the fixed mold 11
Since the resin thickness is smaller than the distance to, the waveforms of c ₁ and c ₂ appear between b ₁ and b ₂ on the graph.

The time t ₁ in Equation 1 above, primary reflected wave reflected from the boundary surface 111 of the fixed mold 11 and the resin filled from the transmission time of the ultrasonic waves into the cavity 13 (b
_It is detected as the time until the detection point in ₁ ). Further, the time t ₂ in Expression 1 is from the time when the ultrasonic wave is transmitted to the moving mold 12
Is detected as the time until the detection time of the reflected wave (c ₁ ) reflected by the boundary surface 121 of the. Then, the time taken for the ultrasonic waves to pass through the resin is T = t ₂ −t ₁ .

FIG. 4 shows the time (seconds) for one cycle of filling, holding pressure switching, holding pressure / metering, and cooling of the resin in the cavity 13 and ultrasonic waves propagating in the resin filled in the cavity 13. 3 is a graph showing the relationship with the propagation velocity (m / sec) of the.

By the above method, the behavior of the resin in the cavity 13 during one cycle is observed by observing the change state of the propagation velocity, and in each step, the filling velocity, the measured value, the holding pressure or the holding pressure time. Changing the molding conditions of
By comparing the changes in the propagation velocity at that time, the optimum molding conditions with uniform weight and good appearance without burrs and insufficient pressure are grasped, and the optimum molding conditions are set in the injection molding machine.

Next, an embodiment of claim 3 of the present application using the mold 6 will be described with reference to FIG. The difference from the above embodiment is that ultrasonic waves are transmitted to the resin in the sprue 14 that communicates with the cavity 13 in the mold, and the behavior of the resin near the inlet in the sprue 14 during one cycle changes in the propagation speed. By observing the above conditions, giving sufficient cooling time, and comparing the changes in the propagation speed at that time, the optimum molding conditions with a uniform weight and a good appearance without burrs or insufficient pressure were understood. The point is to set the molding conditions for the injection molding machine.

Example 1 An electric injection molding machine FANUC 75 tons was used as an injection molding machine, polystyrene (manufactured by Denki Kagaku Kogyo Co., Ltd .: trade name "MW1") was used as a molding resin, and a gate was directly used as a mold. Gate, mold size 270 × 300 × 2
A dish-type injection-molded product was manufactured using a 70 (mm) one.

1. Grasping and setting optimum molding conditions Using the mold 1 shown in FIG.
The behavior of the resin was observed by detecting its propagation speed, and the optimum molding conditions such as filling speed, measured value, holding pressure and holding time were grasped and set.

Example 1- (1) (Filling time) The filling rate was 1 at a measured value of about 80% of the cavity volume.
For each shot, change the condition from the smaller filling speed to 5 steps of 30, 40, 50, 60, 70 mm / sec.
Shot time (seconds) and propagation velocity of resin in Equation 1 (m /
Seconds) was observed. The result is shown in FIG.

The resin filled in the cavity 13 in FIG. 1 is rapidly cooled while being filled in the cavity 13. When the filling speed of the resin into the cavity 13 is increased, the time when the filling of the resin to be filled into the cavity 13 is completed becomes early.

As shown in FIG. 5, the filling speed is 30 m.
When the resin is changed in the range of m / sec to 60 mm / sec, the timing of the resin solidifying becomes earlier, and correspondingly, it is reflected by the boundary surface 121 of the moving die 12 from the time of transmitting the ultrasonic wave. The time t ₂ until the detection time point of the primary reflected wave (c ₁ ) becomes small, and the propagation velocity of the equation 1 becomes large at a timing when the value becomes large with respect to one cycle time.

However, as shown in FIG. 5, when the filling speed is changed from 60 mm / sec to 60 mm / sec, since the resin is approaching the solidified state, the boundary of the moving die 12 from the time of transmitting the ultrasonic wave. The time t ₂ until the detection time point of the primary reflected wave (c ₁ ) reflected by the surface 121 is no longer the difference, and the propagation velocity of the equation 1 has no difference in the timing at which the value increases with respect to one cycle time. Come on.

The filling speed of 60 mm / sec corresponding to the state where there is almost no difference in the value of the propagation velocity of the equation 1 is grasped as the optimum filling speed, and this condition is set in the injection molding machine.

Example 1- (2) (Measured value) The filling speed was fixed at 60 mm / sec, and the holding pressure was lowered so that it was not affected by the holding pressure (270 kg / cm ² ).
Then, the holding pressure is shortened (1 to 2 seconds), the holding pressure switching position is fixed, and the measured value is set to 99.5, 100.5, 10
The conditions were changed from the smaller filling speed in four steps of 1.5 and 102.5 mm, and the relationship between the time (second) of one shot and the propagation speed (m / second) of the resin was observed. The result is shown in FIG.

As shown in FIGS. 6A and 6B, the measured value is 99.0.
Since the density of the resin in the cavity 13 increases when it is changed in the range of 10 mm to 101.5 mm, the primary reflected wave (c ₁ ) reflected by the boundary surface 121 of the moving mold 12 from the time of transmitting the ultrasonic wave. The time t ₂ up to the point of detection of becomes smaller and the propagation velocity of the equation 1 becomes larger.

However, as shown in FIG. 6, when the measured value is changed from 101.5 mm to 102.5 mm,
Since the internal pressure of the resin in the cavity 13 becomes higher than the mold clamping force and the mold is opened, the thickness of the resin through which the ultrasonic waves pass becomes large, and the propagation velocity of Expression 1 is conversely small. Is coming.

In this way, the measured value 101.5 mm corresponding to the maximum value of the propagation velocity of the equation 1 is grasped as the optimum measured value, and this condition is set in the injection molding machine. Example 1- (3) (holding pressure) The filling speed was fixed at 60 mm / sec, and the measured value was 101.5.
The holding pressure is fixed to 290, 310, 3
The conditions were changed from the smaller holding pressure in four stages of 30,350 kg / cm ² and the relationship between the time of one shot (second) and the propagation velocity of the resin (m / second) was observed. The result is shown in FIG. 7.

As shown in FIG. 7 to FIG.
when changed in the range of ^{kg / cm 2 ~330kg / cm 2} , the density of the resin becomes large in the cavity 13, a primary reflected wave reflected by the boundary surface 121 of the movable mold 12 from the transmission time of the ultrasonic The time t ₂ until the detection time of (c ₁ ) becomes small, and the propagation velocity of the equation 1 becomes large.

However, as shown in FIG. 7, when the holding pressure is changed from 330 kg / cm ² to 350 kg / cm ² , the internal pressure of the resin in the cavity 13 becomes higher than the mold clamping force, Since the mold is opened, the thickness of the resin through which the ultrasonic waves pass increases, and
On the contrary, the propagation speed of becomes smaller.

The holding pressure of 330 kg / cm ² corresponding to the maximum value of the propagation velocity of the equation 1 is grasped as the optimum holding pressure, and this condition is set in the injection molding machine. Example 1- (4) (holding time) The filling speed was fixed at 60 mm / sec, and the measured value was 101.5.
The holding pressure is fixed to 330 kg / cm ² , and the holding time is 3, 4, 5 or 6 seconds. The relationship between the shot time (second) and the resin propagation velocity (m / second) was observed. The result is shown in FIG.

The resin filled in the cavity 13 shown in FIG.
The volume of the resin inside shrinks as it cools and solidifies, so that the resin is newly filled only by the shrinkage. Finally, all the resin in the cavity 13 is in a solidified state.

As shown in FIG. 8 and below, the holding pressure is set to 3 seconds to
When the time is changed to 5 seconds, the solidification of the resin newly filled in the cavity 13 progresses, so the detection of the primary reflected wave (c ₁ ) reflected by the boundary surface 121 of the moving mold 12 from the time of transmitting the ultrasonic wave. The time t ₂ up to the point of time becomes small, and the propagation velocity of the equation 1 becomes large.

However, as shown in FIG. 8, when the holding pressure is changed from 5 seconds to 6 seconds, there is no more resin to be newly filled in the cavity 13, and all the resin in the cavity 13 is cooled. As the end of the ultrasonic wave is approached, there is no longer a difference in the time t ₂ from the time when the ultrasonic wave is transmitted to the time when the primary reflected wave (c ₁ ) reflected by the boundary surface 121 of the moving mold 12 is detected, and the propagation velocity of the equation 1 The difference will disappear.

As described above, the pressure holding time of 5 seconds corresponding to the state in which the difference in the propagation velocity of the formula 1 is almost eliminated is grasped as the optimum pressure holding time, and this condition is set in the injection molding machine. Figure 1
Using the mold shown in FIG. 1, the behavior of the resin in the cavity 13 is observed by detecting its propagation velocity as follows,
The optimum molding conditions for the cooling time were grasped and set.

Example 1- (5) (Cooling time) The filling speed was fixed at 60 mm / sec, and the measured value was 101.5.
mm, the holding pressure is set to 330 kg / cm ² , the holding time is set to 5 seconds, and the time for one shot (second) and the propagation velocity of the resin of Formula 1 (m / second) I observed the relationship with. The result is shown in FIG.

As shown in FIG. 9, when the propagation velocity of the equation 1 becomes constant for one cycle time, the cavity 13
It is grasped as the time when all the resins are in a solidified state, and the cooling time of 10 seconds is set as the optimum cooling time in the injection molding machine.

2. The molding condition of the molding filling speed of the molded product is 60 mm / sec, the measured value is 101.5 mm, the holding pressure is 330 kg / cm ² , the holding time is 5 seconds, and the cooling time is 10 seconds. Then, using the injection molding machine and the molding resin, injection molding of a dish-shaped molded product 6 as shown in FIG. 10 was performed. The molded product 6
(N = 75) average weight and the difference (R) between the maximum and minimum variations thereof, the average wall thickness of the portion (n = 75) indicated by X in the molded product 6 shown in FIG. 10 and the maximum variation thereof. The minimum difference (R) was measured. Table 1 shows the relationship between the results and molding conditions, and the average weight (g) of the obtained molded product and the propagation velocity (m / sec) of the formula 1.

Further, the undulation state (height) of the portion indicated by the arrow Y of the molded product 6 shown in FIG. 10, the portion indicated by the arrow Z [corresponding to the rib portion 71 shown in the sectional view of FIG. 10 (b)] The surface state of the molded product to be used] was measured. The results are shown in Table 2.

Comparative Examples 1 to 8 Injection molding of molded articles was carried out in the same manner as in Example 1 except that the filling rate, measured value, holding pressure and holding time were changed to those shown in Table 1.

Table 1 shows the relationship between the molding conditions, the average weight (g) of the obtained molded product and the propagation velocity (m / sec) of the formula 1. Comparative Example 9 As the molding conditions, arbitrary condition 1 (filling speed 30 mm / sec, measured value 99.0 mm, holding pressure 50 kg / cm ² , holding time 6 sec, cooling time 12 sec) was applied to the injection molding machine. After being set, the above-mentioned injection molding machine and molding resin were used to perform injection molding of a dish-shaped molded product 7 as shown in FIG. The average weight of the molded product 6 (n = 75) and its difference (R) between the maximum value and the minimum value, X of the molded product 6 shown in FIG.
The average thickness of the portion (n = 75) and the variation (R) between the maximum and minimum values of the variation were measured. The results and molding conditions are shown in Table 1.

Further, the undulation state (height) of the portion indicated by the arrow Y and the sink state of the portion indicated by the arrow Z of the molded product 6 shown in FIG. 10 were measured. The results are shown in Table 2. Comparative Example 10 As molding conditions, arbitrary condition 1 (filling speed 50 mm / sec, measured value 100.5 mm, holding pressure 220 kg / cm ² ,
The holding pressure time is set to 4 seconds and the cooling time is set to 12 seconds) in the injection molding machine, and the injection molding machine and the molding resin are used to perform injection molding of a dish-shaped molded product 6 as shown in FIG. I went. The average weight of the molded product 6 (n = 75) and its difference (R) between the maximum and minimum values, the average wall thickness of the portion (n = 75) of the molded product 6 shown in FIG. The difference (R) between the maximum and minimum variations was measured. The results and molding conditions are shown in Table 1.

The undulation state (height) of the portion indicated by the arrow Y and the sink state of the portion indicated by the arrow Z of the molded product 6 shown in FIG. 10 were measured. The results are shown in Table 2.

[0055]

[Table 1]

[0056]

[Table 2]

Example 2 According to Example 1, the optimum molding conditions were ascertained. The filling speed was 70 mm / sec, the measured value was 73.5 mm, the holding pressure was 400 kg / cm ² , the holding time was 8 seconds, and cooling was performed. A molding condition of 10 seconds was set in the injection molding machine, and a propeller-type molded product (not shown) was injection-molded using the injection molding machine and the molding resin.

The state of mold opening at the time of molding was observed, and the average weight (n = 75) of the obtained molded products was measured. The results and molding conditions are shown in Table 3. Comparative Examples 11 to 22 A molded article was injection-molded in the same manner as in Example 2 except that the filling rate, measured value, holding pressure and holding time were changed to those shown in Table 3.

The state of mold opening at the time of molding was observed, and the average weight (n = 75) of the obtained molded products was measured. The results and molding conditions are shown in Table 3.

[0060]

[Table 3]

[0061]

Since the method for setting the molding conditions of the injection molding machine according to the invention of claim 1 of the present application is configured as described above, the change state of the propagation velocity of the ultrasonic wave passing through the resin for each shot can be determined. By directly observing the behavior of the resin in the mold by observing, the filling speed, measured value, holding pressure or holding pressure as basic conditions for manufacturing an injection-molded product with stable weight and appearance. It is possible to grasp the optimum molding condition of time and set the optimum molding condition in the injection molding machine.

Since the molding condition setting method for the injection molding machine according to the second aspect of the present invention is configured as described above,
By observing the change state of the propagation velocity of the ultrasonic wave passing through the resin for each shot, the behavior of the resin in the mold is directly detected, and finally the filling speed and metering without burr or pressure shortage By setting the optimum molding conditions such as value, holding pressure, and holding time, it is possible to manufacture an injection-molded product with stable weight and appearance.

Since the molding condition setting method for the injection molding machine according to the third aspect of the present invention is configured as described above,
By directly observing the behavior of the resin in the mold by observing the changing state of the propagation velocity of the ultrasonic waves passing through the resin, it is a basic condition for manufacturing a stable injection molded product such as weight and appearance. The optimum molding conditions of the cooling time can be grasped and the optimum molding conditions can be set in the injection molding machine.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a portion of a mold used in an embodiment of the present invention.

FIG. 2 is a sectional view showing a part of another mold used in a different embodiment of the present invention.

FIG. 3 is an explanatory diagram of waveforms of an ultrasonic transmitted wave and a reflected wave according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing the relationship between one cycle time and the propagation velocity of Expression 1 in the example of the present invention.

FIG. 5 is an explanatory diagram showing one cycle time and the propagation speed of Expression 1 when grasping the optimum filling speed in the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing one cycle time and a propagation velocity of Expression 1 when grasping an optimum metric value in an example of the present invention.

FIG. 7 is an explanatory diagram showing one cycle time and a propagation velocity of Expression 1 when grasping an optimum holding pressure in an example of the present invention.

FIG. 8 is an explanatory diagram showing one cycle time and the propagation velocity of Expression 1 when grasping the optimum holding pressure time in the example of the present invention.

FIG. 9 is an explanatory diagram showing one cycle time and the propagation velocity of Expression 1 when grasping the optimum cooling time in the example of the present invention.

FIG. 10A is a perspective view showing a molded product obtained according to an embodiment of the present invention, and FIG. 10B is a vertical sectional view of the molded product.

[Explanation of symbols]

 1,6 Mold 2 Ultrasonic probe 3 Ultrasonic measuring instrument 11 Fixed mold 12 Moving mold 13 Cavity 4 Indicator 5 Hydraulic cylinder 7 Molded product

Claims (3)

[Claims] 1. An injection molding machine equipped with an injection molding die provided with a cavity for forming a molded product, a reflected wave time for transmitting ultrasonic waves into the die and passing through the resin in the cavity for reflection. While continuously detecting and converting to the propagation speed,
By changing the filling speed, measured value, holding pressure or holding time of the resin to be filled in the cavity and observing the changing state of the propagation velocity for each shot, the corresponding filling speed and measured value can be observed from this changing state. A method for setting a molding condition for an injection molding machine, comprising: grasping an optimum molding condition of a holding pressure or a holding time and setting the optimum molding condition in an injection molding machine. 2. The operation of grasping the optimum molding conditions of the filling speed, the measured value, the holding pressure and the holding time of claim 1 and setting the optimum molding conditions in the injection molding machine are performed in this order, and finally A method for setting molding conditions for an injection molding machine, characterized in that all of these optimum molding conditions are set in the injection molding machine. 3. An injection molding machine equipped with an injection molding die provided with a sprue communicating with a cavity for forming a molded product, wherein ultrasonic waves are transmitted into the die and reflected through a resin in the sprue. While continuously detecting the reflected wave time and converting it to the propagation velocity, the change state of the propagation velocity of one shot that gives sufficient cooling time for the resin filled in the sprue is observed, and the propagation velocity corresponding to the cooling time is A method for setting molding conditions for an injection molding machine, which comprises grasping a time when a certain value is reached as an optimum cooling time and setting the optimum cooling time in the injection molding machine.