JP2992168B2 - How to adjust the origin of toggle type and crank type mold clamping mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of adjusting the origin of a toggle type clamping mechanism or a crank type clamping mechanism of an injection molding machine or the like.

[0002]

2. Description of the Related Art As a mold clamping mechanism of an injection molding machine and the like, a toggle mold clamping mechanism using a toggle mechanism and a crank mold clamping mechanism are known. The toggle-type and crank-type mold clamping mechanisms generate a set mold clamping force when the toggle link and the crank link are fully extended. Therefore, it is necessary to detect a state in which the toggle link and the crank link are fully extended. In a mold clamping mechanism of a type in which a toggle mechanism or a crank mechanism is driven by a motor, generally, the rotational position of the motor is detected, and the rotational position of the motor is detected as the position of the mold clamping mechanism. Mechanism, crank mechanism crosshead position, toggle mechanism,
The position and the like of the movable mold moved by the crank mechanism are detected. And generally, the toggle mechanism,
The position of the crank mechanism, that is, the position of the movable mold, is based on the state where the toggle link and the crank link that generate the set mold clamping force are fully extended.

In an injection molding machine and the like, the toggle mechanism of the toggle mechanism, the toggle link of the crank mechanism, and the state in which the crank link is fully extended are used as origins, and various positioning positions such as a mold closing position, a mold protection start position, and a mold opening completion position. Is controlled by the position of the mold clamping mechanism (the rotational position of the motor). Further, the origin of the toggle-type mold clamping mechanism or the crank-type mold clamping mechanism is set at the position of the mold-clamping mechanism when the mold clamping force is generated in the mold with the toggle link or the crank link fully extended (the motor position). (Rotational position) is set as the origin.

[0004]

When the origin is lost for any reason (replacement of a motor, replacement of a position detector for detecting the rotational position of the motor, etc.), the toggle type and crank type mold clamping mechanisms are not used. The origin must be adjusted to establish the coordinate system. As described above, the toggle-type and crank-type mold clamping mechanisms determine the position of the drive source (the rotational position of the motor) when the set mold clamping force is generated with the toggle link and the crank link fully extended. This is the origin of the tightening mechanism. Therefore, when the load is applied to the mold clamping mechanism, the position of the mold clamping mechanism (rotational position of the motor) when the toggle link and the crank link are fully extended without applying a load is the same. If so, it suffices that the toggle link and the crank link be fully extended without applying a load to the mold clamping mechanism and set at that time as the origin. But,
The position of the mold clamping mechanism where the toggle link and the crank link extend (the rotational position of the motor) differs between the free state and the application of the mold clamping force without application of a load. Although the reason is not clear, it is presumed that play at each pivot point of the toggle link and the crank link has an influence. As a result, it is necessary to extend the toggle link and crank link while generating the mold clamping force in order to perform home search.
The work of finding the origin is very troublesome and difficult. SUMMARY OF THE INVENTION An object of the present invention is to provide a method of adjusting the origin of a toggle type and a crank type mold clamping mechanism which can easily find the origin.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a position of a mold clamping mechanism when a toggle link and a crank link of the mold clamping mechanism are extended to a free state without applying any load to the mold clamping mechanism. The difference between the position of the mold clamping mechanism when a predetermined mold clamping force is generated in the mold with the toggle link and the crank link of the mold clamping mechanism fully extended is measured in advance. When the origin of the clamp is lost, the difference is corrected to the position of the clamp when the toggle link and crank link of the clamp are fully extended with no load applied to the clamp. To determine the origin.

If the toggle link and the crank link cannot be fully extended for some reason, the toggle link and the crank link of the mold clamping mechanism are set in a free state without applying any load to the mold clamping mechanism. Measure the distance between the rear platen and the crosshead or the rotation angle of the crank link when the
The error between the position of the mold clamping mechanism at this time and the position of the mold clamping mechanism when a predetermined mold clamping force is generated in the mold with the toggle link and the crank link of the mold clamping mechanism fully extended. Measure in advance and measure the distance between the rear platen on which the toggle mechanism is mounted and the crosshead, or the rotation angle of the crank link, without applying any load to the mold clamping mechanism. When the toggle link or crank link is fully extended without any load, the difference between the distance between the rear platen and the crosshead or the difference between the crank link rotation angle and the toggle link with no load applied to the mold clamping mechanism. The position of the mold clamping mechanism corresponding to the measured distance when the link and crank link are fully extended is taken as the origin, and the position obtained by correcting the difference to the position is obtained. The set as the position of the clamping mechanism.

[0007]

When the origin of the mold clamping mechanism is lost, no load is applied to the mold clamping mechanism, and the mold clamping mechanism is set in a free state and the toggle link and the crank link of the mold clamping mechanism are fully extended. If a position obtained by correcting the difference is set as the origin of the mold clamping mechanism at this time, the difference is a difference between when the load is applied to the mold clamping mechanism and when it is not applied. Accordingly, the position of the mold clamping mechanism in a state where the crank link is fully extended and the mold clamping force is generated is set as the origin.

If it is necessary to adjust the origin when the toggle link and the crank link cannot be fully extended for some reason, the position of the drive source for driving the toggle mechanism or the crank mechanism is required. The position of the crosshead corresponds to the position of the crosshead on a one-to-one basis, and the origin is adjusted using the fact that it is in a predetermined proportional relationship. In this case, the distance between the rear platen to which the toggle mechanism is attached and the crosshead or the rotation angle of the crank is measured without applying any load to the mold clamping mechanism. When the toggle and the crank are fully extended without applying any load to the mold clamping mechanism, the crosshead is measured from the position of the crosshead or the rotation angle of the crank measured at the position of the crosshead at the origin. The amount of movement of the drive source to be moved to the position or the crank rotation angle is obtained. If the error is corrected and set in this movement amount, the position of the toggle mechanism and the position of the mold clamping mechanism of the crank mechanism at the time point where the crank rotation angle is measured can be obtained. Then, this position is set to the position of the mold clamping mechanism that generates a predetermined mold clamping force in the mold clamping mechanism and sets the origin at the state where the toggle link and the crank link of the mold clamping mechanism are fully extended.

[0009]

FIG. 1 is a structural view of a main part of a toggle-type mold clamping mechanism of an injection molding machine according to an embodiment for carrying out the method of the present invention. In the drawing, reference numeral 1 denotes a rear platen to which a toggle mechanism 3 is attached, and 2 denotes a moving platen to which a movable mold is attached. The moving platen 2 is guided by a tie bar (not shown).
Is moved left and right in the figure by the toggle mechanism 3. The toggle mechanism 3 includes a set of toggle links composed of links L1, L2, L5 and links L3, L4, L6.
And two sets of toggle links. One ends of the links L1 and L3 are rotatably mounted on the rear platen 1 and pins P1 and P4, and one ends of the links L2 and L4 are connected to the moving platen 2 and the pins P3 and P3.
It is pivotally mounted at P6. The other ends of the links L1 and L2 and the other ends of the links L3 and L4 are rotatably mounted on pins P2 and P5. Link L
1 and L3, the link L is formed by pins P7 and P9 at a substantially intermediate portion.
5 and L6 are rotatably mounted on the shaft, and the other ends of the links L5 and L6 are rotatably mounted on the crosshead 5 on pins P8 and P10.

The crosshead 5 is integrally provided with a ball nut screwed into the ball screw 4. The rotation of the ball screw 4 causes the crosshead 5 to move linearly right and left in the figure, driving the toggle mechanism 3 and moving the moving platen 2. Let it. The shaft of the ball screw 4 is rotatably mounted on a rear platen, and a pulley 6 is attached to one end. A servo motor M is mounted on the rear platen 1. A position detector Pc such as a pulse coder is attached to the servomotor, and detects the rotational position of the servomotor M. A pulley 7 is mounted on the rotor shaft of the servo motor M,
Timing belt (not shown) between the pulleys 6 and 7
And pulleys 6, 6
Driving the timing belt, pulley 7, and ball screw 4,
The crosshead 5 is moved to drive the toggle mechanism 3, and the moving platen 2 is moved right and left in the figure to close, close, and open the mold. The structure of the toggle-type mold clamping mechanism is the same as that of a conventional toggle-type mold clamping mechanism driven by a motor.

In the toggle-type mold clamping mechanism described above, a set mold clamping force is generated in a state where the toggle link in the state shown in FIG. This is the origin of the toggle type clamping mechanism.
That is, in this state, the rotational position of the servomotor detected by the position detector Pc attached to the servomotor M is used as the origin position of the mold clamping mechanism. The counter for detecting the rotation position of the motor M is set to “0”. When the toggle link is fully extended, the pins P1, P2 and P2 at the pivot points of the link are set.
The state in which P3 and pins P4, P5, and P6 are respectively arranged on the position straight line is detected by detecting the straight line detecting means.

However, in a state where the moving platen 2 can move freely without actually applying the mold clamping and applying any load to the toggle type mold clamping mechanism, the toggle link is fully extended as shown in FIG. The rotational position of the servomotor M at
Moving platen 2 and front platen 2 not shown
The rotational position of the servomotor M when a mold clamping force is actually generated in the mold attached to the cylinder to extend the toggle link is different. For example, a counter for counting pulses from the position detector Pc is set to “0” in a state where the toggle link is extended without applying a load to the toggle mechanism in a state where the moving platen 2 can be freely moved, and Even when the mold clamping force is actually generated and the servo motor M is rotated until the counter becomes “0”, the set mold clamping force is not obtained and the toggle link is fully extended. is not. Although the reason is not clear, it is presumed that play at the positions of the pins P1 to P6 at the respective pivot points in the toggle mechanism causes the above-described phenomenon.

Therefore, when the origin is to be determined, it must be performed in a state where the mold clamping force is actually generated. However, when the origin is lost for some reason during the work and it becomes necessary to adjust the origin, the toggle link is extended fully while generating the mold clamping force, and the pins P1 to P3 or the pins P4 to P6 It is very troublesome and difficult to adjust the origin by detecting the positions arranged in a straight line and setting the above-mentioned counter to "0" using this position as the origin.

Accordingly, the present invention provides a method of shipping a product such as an injection molding machine using the toggle-type mold clamping mechanism in advance.
The rotational position of the servomotor M when the toggle link of the toggle mold clamping mechanism is fully extended without any load being applied to the toggle mechanism is detected. For example, at this time, the value of the counter that counts the pulses from the position detector Pc is set to “0”, and then, when the toggle link is fully extended and a predetermined mold clamping force is generated in the mold. The difference from the rotational position of the motor is determined. That is, when a predetermined clamping force is generated and the pins P1 to P3 or the pins P4 to P6 are arranged in a straight line and the toggle link is fully extended, the value X of the counter becomes the difference. This difference X is stored in the control device of the injection molding machine or the like.

Thereafter, when the injection molding machine is shipped and the origin adjustment needs to be performed for some reason (for example, replacement of the position detector) during use of the injection molding machine, the mold clamping force is reduced. Without generating, the moving platen 2 is set in a free state, and the servomotor is driven to detect the position where the pins P1 to P3 or the pins P4 to P6 are arranged in a straight line, and the position at which the toggle link is fully extended. Is controlled by driving the servo motor M so that When this positioning is completed, the servomotor is further driven by the difference X, and this state is set as the origin, and if the counter is set to "0", the origin adjustment is completed.

In the above method, the toggle link is extended completely. If the toggle link cannot be extended for any reason, the origin is adjusted by the following method. First, the amount of movement of the crosshead with respect to the amount of rotation of the servomotor M (one pulse detected by the position detector Pc) is determined. Crosshead 5
Is moved by the servomotor M via the pulley 7, the timing belt, the pulley 6, and the ball screw 4. Therefore, the amount of movement of the crosshead 5 with respect to the amount of rotation of the servomotor M is linear. M
The relational expression of the amount of movement of the crosshead 5 with respect to the amount of rotation is uniformly obtained. Then, the distance A between the crosshead 5 and the rear platen 1 when the toggle link is fully extended without applying any load to the toggle-type mold clamping mechanism is measured and stored in advance.

When adjusting the origin, the distance Y between the crosshead 5 and the rear platen 1 is measured without applying any load to the toggle-type mold clamping mechanism, and the distance Y and the stored toggle link are fully extended. (A)
−Y), the rotational movement amount of the servo motor M corresponding to the above relational expression is obtained. The amount of rotational movement of the servo motor thus obtained represents the rotational position of the servo motor when the state where the toggle link is fully extended without applying any load to the toggle mechanism 3 is set to “0”. Accordingly, the difference X between the rotational position of the servomotor when the specified clamping force is generated in the toggle mechanism in a state where the toggle link is fully extended and the case where no clamping force is generated is corrected. I do. That is, if a value obtained by adding the difference X to the rotation amount is set in the counter that stores the rotation position of the servo motor, the value of this counter is applied to the toggle mechanism in a state where the toggle link is fully extended by a predetermined mold clamping force. This indicates the rotational position of the servomotor when the state in which is generated is set as the origin, and the origin adjustment ends.

FIG. 2 is a front view of a crank type mold clamping mechanism to which the present invention is applied. 2, reference numeral 10 denotes a rear platen, 11 denotes a moving platen, and a crank mechanism 12 is provided between the rear platen 10 and the moving platen 11.
Is installed. A servo motor M for driving a crank mechanism 12 is attached to the rear platen 10, and a pulley 14 is fixed to a rotor shaft 13 of the motor M. A crankshaft 16 is rotatably supported by the rear platen 10, and a pulley 15 is fixed to the crankshaft, and a timing belt 17 is suspended between the pulleys 14 and 15. The crankshaft 16 has a crank link L1
0 is fixed, and a crank link L11 is rotatably connected to the other end of the link L10 by a pin P11. The other end of the link L11 is rotatably mounted on the moving platen 11 by a pin P12. Although a position detector for detecting the rotational position of the servo motor M is attached to the servo motor M, it is not shown in FIG.

In the above configuration, when the servo motor M is driven, the pulley 14, the timing belt 17, the pulley 1
When the crankshaft 16 of the crank mechanism 12 rotates via the link 5 and the link L10 rotates, the moving platen 11 moves in the left-right direction in FIG. Then, similarly to the toggle type mold clamping mechanism, the set mold clamping force is generated in a state where the crank link shown in FIG. 2 is fully extended. Also, in the case of the crank type mold clamping mechanism, similarly to the toggle type mold clamping mechanism, when the crank link is extended and the mold clamping force is generated, the moving platen 11 is released to apply a load to the crank mechanism 12. When the crank link is fully extended, the position of the mold clamping mechanism, that is, the rotational position of the servomotor that drives the crank mechanism 12 is different.

Therefore, similarly to the toggle type mold clamping mechanism, when the mold clamping force is generated to extend the crank link, the moving platen 11 is released to extend the crank link without applying a load to the crank mechanism 12. The difference X between the rotational position of the servo motor M and the time X is measured in advance. When the origin is lost, the servomotor M is driven without applying a load to the crank mechanism 12 to position the cranklink at a position where the cranklink is fully extended, and the rotational position of the servomotor M is corrected by the above difference to form a mold. The position of the mold clamping mechanism (rotational position of the servo motor M) at which the crank link is fully extended by generating the clamping force can be obtained as the origin.

As another method, the relationship between the rotation amount of the crankshaft 16 or the click link L10 and the rotation amount of the servo motor M is obtained. The crankshaft 16 is driven by a pulley 14 and a timing belt 1 by a servomotor M.
7, since it is driven via the pulley 15, the rotation angle of the crankshaft 16 or the click link L10 with respect to the rotation amount of the servomotor M has a linear relationship, and the crankshaft 16 with respect to the rotation amount of the servomotor M. Alternatively, the relational expression of the rotation angle of the clink link L10 is uniformly obtained. Then, without applying any load to the mold clamping mechanism in advance,
The rotation angle α of the crankshaft 16 or the click link L10 when the crank link is fully extended (normally, this angle is a predetermined angle) is measured and stored.

When the origin is adjusted, the rotation angle β of the crankshaft 16 or the link clink L10 is measured without applying any load to the mold clamping mechanism, and the rotation angle β and the stored crank link are extended. The rotational movement amount of the servo motor M corresponding to the difference (α-β) from the rotation angle α of the crankshaft 16 or the clink link L10 at the time of turning off is obtained from the above relational expression. The rotation amount of the servo motor thus determined represents the rotation position of the servo motor when the state where the crank link is fully extended without applying any load to the crank mechanism 12 is set to “0”. Therefore, the difference X between the rotational position of the servo motor M when the specified clamping force is generated in the crank mechanism in a state where the crank link is fully extended and when the clamping force is not generated at all is set to this rotation amount. By correcting, the origin of the mold clamping mechanism is obtained.

In each of the above embodiments, a servomotor is used as a driving source for driving the mold clamping mechanism. However, the origin adjusting method of the present invention can be applied to a case where a motor other than a motor is used.

[0024]

According to the present invention, when the origin of the toggle type or crank type mold clamping mechanism is lost, the origin can be simply and easily adjusted without generating a mold clamping force.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram of a toggle-type mold clamping mechanism of an injection molding machine according to a first embodiment for carrying out a method of the present invention.

FIG. 2 is a configuration diagram of a main part of a crank type mold clamping mechanism according to a second embodiment of the present invention for implementing the method of the present invention.

[Explanation of symbols]

 1,10 Rear platen 2,11 Moving platen 3 Toggle mechanism 4 Ball screw 5 Cross head 6,7,14,15 Pulley M Servo motor Pc Position detector P1-P12 Pin L1-L11 Link 12 Crank mechanism

Continuation of front page (56) References JP-A-63-116821 (JP, A) JP-A-62-160219 (JP, A) JP-A-63-115717 (JP, A) JP-A-63-173617 (JP) (A) JP-A-61-71164 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/76-45/80 B29C 45/64-45/68 B29C 33/20 -33/24 B22D 17/26

Claims (2)

(57) [Claims] 1. A mold clamping mechanism that generates a set mold clamping force in a state where a toggle link or a crank link of a toggle type or a crank type mold clamping mechanism is fully extended, and uses this state as an origin of the mold clamping mechanism. In the method of adjusting the origin of the part, the position of the mold clamping mechanism when the toggle link or the crank link of the mold clamping mechanism is fully extended without applying any load to the mold clamping mechanism, and The difference between the position of the mold clamping mechanism and the position of the mold clamping mechanism when a predetermined mold clamping force is generated in the mold with the toggle link or crank link fully extended is measured in advance, and the origin of the mold clamping mechanism is lost. When the mold clamping mechanism is in a free state without applying any load to the mold clamping mechanism and the toggle link or the crank link of the mold clamping mechanism is fully extended, the difference is corrected to the position of the mold clamping mechanism to determine the origin. Origin adjustment method for toggle or crank type mold clamping mechanism. 2. A mold clamping mechanism for generating a set mold clamping force in a state where a toggle link or a crank link of a toggle type or a crank type mold clamping mechanism is fully extended, and using this state as an origin of the mold clamping mechanism. In the method of adjusting the origin of the part, the distance between the rear platen and the crosshead or the rotation of the crank link when the toggle link or the crank link of the mold clamping mechanism is fully extended without applying any load to the mold clamping mechanism Measure the angle in advance,
The error between the position of the mold clamping mechanism at this time and the position of the mold clamping mechanism when a predetermined mold clamping force is generated in the mold with the toggle link or crank link of the mold clamping mechanism fully extended is previously determined. Measure the distance and measure the distance between the rear platen with the toggle mechanism and the crosshead or the rotation angle of the crank link without applying any load to the mold clamping mechanism. Due to the difference between the distance between the rear platen and the crosshead or the rotation angle of the crank link when the toggle link or the crank link is fully extended without adding the toggle link or the crank link, the toggle link or the The position of the mold clamping mechanism corresponding to the measured distance when the state where the crank link is fully extended is set as the origin is obtained, and the error is corrected to the position. Toggle or origin adjusting method of a crank type mold clamping mechanism for setting the position as the position of the mold clamping mechanism.