JPS61252126A - Automatic mold clamping force regulating device - Google Patents

Abstract

PURPOSE:To achieve the automatic regulation of mold clamping force smoothly and surely by a method wherein the fixing frame of mold clamping device and the link housing of the same are provided with one set of unit sensor, consisting of one set of sensor scale and sensor head, respectively. CONSTITUTION:The fixing frame 10 and the ink housing 16 of the mold clamping device are provided with the sensor scale 24 and the sensor head 26 respectively so as to be opposed. The diameter (d) of tie bar 18, the length (l1) of the tie bar 18 between a fixed die 12 and the link housing 16 in the limit of retreating of die height and the Young's modulus E of the tie bar 18 are memorized previously in a memory 34. A signal, detected by the sensor head 26 under no-load condition, is inputted into CPU 30 and the position (l2) of die height is calculated. Subsequently, the position (l3) of die height is calcu lated under load condition in the same manner. In this case, the amount of displacement DELTAl of the link housing 16 upon clamping the mold is expressed by l2-l3 and the load F (mold clamping force) may be obtained by pid<2>.E.DELTAl/(l1-l2).

Description

[Detailed Description of the Invention] [Technical field to which the invention pertains] This invention relates to a machine for molding metal or plastic having a toggle type mold opening/closing mechanism, that is, a tie casting machine, essentially an injection molding machine, etc. This invention relates to a device that automatically adjusts.

[Prior art and its problems]

Conventionally, this type of automatic mold clamping force adjustment device R required a load sensor for detecting the mold clamping force and a positional sensor for detecting the die hide (mold open) position. However, conventional load sensors are provided by drilling holes in tie bars and detect changes in stress at the center of the tie bars.

Further, the die-hide position sensor is provided by adding a gear to a gear box for adjusting the amount of die-hide attached to the link housing, and detects the position from the rotation speed and rotation angle of this gear. For this reason, in conventional mold clamping force automatic adjustment devices, not only is it necessary to prepare only one type of sensor, but each sensor requires complicated installation, which increases manufacturing costs and makes it difficult to maintain accuracy. There is.

[Purpose of the invention]

The present invention provides an automatic mold clamping force adjustment device that can detect mold clamping force and die hide position using a single sensor, and can calculate an appropriate die hide adjustment distance.

[Key points of the invention]

The automatic mold clamping force adjustment device according to the present invention is a mold clamping device configured such that a mold clamping cylinder performs a mold clamping operation on a movable die with respect to a fixed die via a toggle mechanism, in which a fixed frame and a mold clamping cylinder are provided. A sensor scale and a sensor head are arranged facing each other on the link housing, detect the die-hide position 12' when the mold is open and under no load, and detect the displacement Δl of the link housing when the mold is in the clamped state, and calculate these detected values. The present invention is characterized by providing means for calculating the mold clamping force and the die-hide adjustment distance from the above.

In the above automatic mold clamping force adjustment device, the mold clamping force F is calculated by the following formula: However, πd2: cross-sectional area of tie bar E: Young's modulus 11: Length of tie bar It can be calculated by

In addition, the die-hide adjustment distance lx is calculated using the following formula, where πd2:
Cross-sectional area of tie bar E: Young's modulus 11: Length of tie bar ΔF: v! 4 can be calculated based on the required mold clamping force.

[Embodiments of the invention]

Next, embodiments of the automatic mold clamping force adjustment device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a mold clamping device having a toggle type mold opening/closing mechanism that implements the mold clamping force automatic adjustment device of the present invention.

That is, in FIG. 1, the reference symbol /θ indicates a fixed frame, and on this fixed frame /θ, a fixed die /2) a movable die /DA and a link housing /6 are arranged facing each other along the axis of the tie bar /I. has been done. A toggle mechanism θ is provided between the movable die/4t and the ring housing/6, and this toggle mechanism 2θ advances the movable die/4t relative to the fixed die/2 under the action of the clamping cylinder 22. It is configured to perform the required mold clamping.

However, in the present invention, the sensor scale 241 is attached to the fixed frame /θ and the link housing /6.
and the sensor head 26 are arranged facing each other (
(See Figure 2). It is to be noted that the sensor scale body and the sensor head body are preferably of a type that can magnetically or optically sense relative movement and detect the amount of displacement thereof. Further, the sensor scale 2g and the sensor head 26F'i are not limited to the illustrated example, and may be provided on either the fixed frame /θ or the link housing /6.

By the way, as shown in Fig. 1, the mold clamping device is in a no-load state (
When the toggle mechanism is in a state where the mold is opened and the mold is not clamped, the data detected by the sensor head 26 indicates the die-hide position. Next, when the toggle mechanism θ is operated to close the mold and the movable die/l is moved to the fixed guide/J side to close the mold, the tie bar/l is extended to the side opposite to the movable die/l (direction B). At the same time, link housing/
6 also moves in the direction B together with the tie bar /l, and the amount of this movement can be detected by the sensor head 2B (see FIG. 3).

Therefore, in the present invention, based on the data detected by each sensor head 26, the system configuration shown in FIG. . That is, referring to FIG. 9, data detected by the sensor head 26 is input to CPtJJo via the sensor output amplifier 2. In this case, signals confirming the no-load state and mold clamping state of the mold clamping device are sent to the I10 interface 32.
is inputted to the CPUJθ via. In addition, reference number 3
indicates a storage device.

In such a system configuration, the storage device 341 stores in advance the diameter d of the tie bar/I, the fixed diameter at the die height retraction limit (0 point), the length 11 of the tie bar/I between 2 and the link housing/6, and The Young's modulus E of the tie bar/l is stored as data, for example, a value calculated based on the relationship between the mold clamping force and the elongation of the tie bar/l. Therefore, in the no-load state shown in FIG. 7, the signal detected by the sensor head 2B is transmitted to the CPUJθ
is input and the die-hide position is converted to a distance quantity and becomes the die-hide position! Calculate 2. Next, in the load state shown in FIG. 3, the signal detected by the sensor head B is converted into a distance value 15 in the same manner as described above. Therefore, the amount of displacement Δt of the link housing /6 during mold clamping in this case is expressed as 1 Δ1 = 1!2-1 s.

Further, the relationship between the displacement amount Δl and the load F (W tightening force) is expressed by the following equation.

However, A: Cross-sectional area of tie bar E: Young's modulus l! : Longer tie bar =! t-! 2) The above formula (1)
In, A is the cross-sectional area of the tieverter, so A
= (l x -! - d", the load F is found as follows "l3Sr.

In addition, when automatically adjusting the mold clamping force, the change in mold clamping force Δ
For F, the necessary die-hide adjustment distance (travel amount)
The relationship with lx is expressed by the following equation.

In this case, since lX is negligibly small compared to the tie bar length = 11-12, the die-hide adjustment distance l
! x is determined by the following equation based on equation (3) above.

The above arithmetic processing can be programmably executed between the CPU 30 and the storage device 34t shown in FIG. 5 based on, for example, chart 70 shown in FIG.

〔Effect of the invention〕

As is clear from the embodiments described above, according to the present invention,
By providing a single sensor consisting of seven sets of sensor scales and sensor heads on the fixed frame and link housing of the mold clamping device, it is possible to appropriately determine the die, die hide position, mold clamping force, and die hide adjustment distance. I can do it,
Thereby, automatic adjustment of the die clamping force can be achieved smoothly and reliably.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a mold clamping device having a toggle type mold opening/closing mechanism showing an embodiment of the mold clamping force automatic adjustment device according to the present invention, and Fig. 2 is a schematic diagram showing the mounting state of the senna shown in Fig. 1. 3 is an explanatory diagram of the operation of the mold clamping device shown in FIG. 7, FIG. 9 is an automatic control system diagram of the device of the present invention, and FIG. 5 is an illustration of the operation of the automatic control system shown in FIG. This is a flowchart diagram. /θ...Fixed frame /K...Fixed die/G...Moving die /6...Link housing lt...Tie bar Kθ...°Toggle mechanism 22...Mold clamping cylinder 2... ...sensor scale, 2
6...Sensor head 2t...Amplifier 3θ-CP
U 32...I10 interface 3G...Storage device patent applicant Toshiba Machine Co., Ltd. Applicant's agent Patent attorney Hama 1) Haruo FIG, 3 IG 4 Procedural amendment (self-anchor July 23, 1985)

Claims (3)

[Claims] (1) In a mold clamping device configured so that a mold clamping cylinder performs a mold clamping operation on a movable die with respect to a fixed die via a toggle mechanism, a sensor scale and a sensor head are attached to a link housing provided with a fixed frame and a mold clamping cylinder. The die height position l_2 is detected when the mold is open and there is no load, and the displacement amount Δl of the link housing when the mold is clamped is detected, and the mold clamping force and die height adjustment distance are calculated from these detected values. An automatic mold clamping force adjustment device, characterized in that it is provided with a means for adjusting the mold clamping force. (2) In the mold clamping force automatic adjustment device according to claim 1, the mold clamping force F is calculated by the following formula. F=(πd^2・E・Δl)/(l_1-l_2) However, πd^2: Cross-sectional area of tie bar E: Young's modulus l_1: Length of tie bar (3) In the automatic mold clamping force adjustment device according to claim 1, the die height adjustment distance l_x is calculated by the following formula. l_x=(πd^2・E)/(ΔF・(l_1−l_2
)) However, πd^2: Cross-sectional area of tie bar E: Young's modulus l_1: Length of tie bar ΔF: Mold clamping force that requires adjustment