JPH0671413A - Method for adjusting die height in die casting machine - Google Patents

Abstract

PURPOSE:To provide a die casting machine, in which the die height adjustment rejecting the errors caused by overrun with the inertia of a link housing and a motive power system and back-lash, etc., of the transmitting mechanism of looseness of the motive power system and gear, etc., and the error caused by delay of a control system can be executed. CONSTITUTION:In the die casting machine having the link housing, movable plate and a fixed plate and adjusting the die height by shifting the link housing, in the case of adjusting the die height by advancing or retreating the link housing by the prescribed distance, once the retreat is started and a stopping command is transmitted at the optional position P1 after the link housing reaches to the stationary speed during shifting to the retreat and also, this retreat limit distance is measured. Thereafter, the advance is started, and when the link housing comes to the position adding the retreat distance P2 and the stopping command transmitting distance A to the prescribed distance P4-P0, the stopping command is transmitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die height adjusting method for a die casting machine or an injection molding machine for adjusting a die height by moving a link housing, and more particularly to a die height adjusting method for improving a die height setting accuracy.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 1, a die casting machine for performing mold clamping through a toggle mechanism has a link housing 1 and a fixed platen 2 and four tie bars 3 vertically and horizontally.
The movable platen 4 is reciprocally arranged between the link housing 1 and the fixed platen 2 so that the tie bar 3 can be used as a guide to move back and forth. The toggle mechanism 5 is composed of a pair of upper and lower links 6, 7 and 8 which are flexibly connected to each other and a crosshead 9 which connects the upper and lower links 8 to each other. 7 is pin-jointed to the movable platen 4, and the connecting portions of both links 6 and 7 are connected to a crosshead 9 via another link 8, and the crosshead 9 is clamped at the outer end of the link housing 1. It is fixed to the tip of the piston rod 11 of the schilling 10. A tightening nut 12 is screwed into a penetrating portion of the tie bar 3 of the link housing 1, and a sprocket wheel 13 fixed to the tightening nut 12 is rotationally driven by a die height adjusting motor 14 (shown in FIG. 2) via a chain 15. The link housing 1 can be moved forward or backward in the direction of the movable platen 4. Reference numeral 16 shown in FIG. 3 is a limit switch for detecting the movement of the crosshead 9 and stopping the die height adjusting motor 14, and is attached to a stand 17 stretched horizontally from the link housing 1. The scale 18 is for reading the mounting position of the limit switch 16. A position sensor 20 is fixedly installed on the link housing 1, and the stop position can be measured by the magnetic scale 30.

In a die casting machine having such a structure,
For example, when the fixed mold 2a or the movable mold 4a is replaced, the die height (mold thickness) changes, so it is necessary to adjust the die height (work to match the mold thickness).
The conventional die casting adjustment method is to open new molds and attach new dies to the fixed platen 2 and movable platen 4, respectively, and operate the mold clamping cylinder 10 to advance the piston rod 11 to move the movable platen 4 to the fixed platen 2. In the direction as shown in FIG. 4, both molds 2a, 4
Move until a touches the metal. In this case, when the die height H is larger than the previous die height H ₀ , the nodes of the links 6 and 7 are bent and not on a straight line, so the link housing 1 must be retracted by a required distance. Therefore, after the die height adjusting motor 14 is driven in the reverse direction to rotate the tightening nut 12 in the unlocking direction (counterclockwise direction) to secure the retreat distance of the link housing 1, the mold clamping cylinder 10 is operated again and the piston rod 11 is moved. Move forward near the stroke end. After that, the end face of the link housing 1 and the tightening nut 1
The tie height adjusting motor 14 is driven in the normal direction by the distance of the gap between the two and the tightening nut 12 is moved forward to stop the die height adjusting motor 14 when they come into contact with each other. On the other hand, when the die height H is smaller than the previous die height H ₀ , both dies do not touch the metal even if the piston rod 11 of the mold clamping cylinder 10 is moved forward to end the stroke. Therefore, the die height adjusting motor 14 is driven to rotate normally. The die height adjusting motor 14 is stopped when the link housing 1 and the movable platen 4 are integrally advanced by the advancing of the attached nut 12 and both dies are metal-touched.

[0004]

In the conventional die height adjusting method which is performed when the die height adjustment is required as described above, when the link housing is moved forward or backward, the die height adjusting motor 14 is rotationally driven and simply moved forward. After stopping, or after moving backward, it stops. However, in such a method, a subtle deviation occurs between the stop target position and the stop position (actual value) due to the following three reasons, and the die height setting accuracy deteriorates. That is, the first reason is the overrun due to the delay of the control system (the time lag from the detection of the sensor to the operation command), the second reason is the overrun due to the inertia of the link housing and the power system, and the third reason is the forward movement. There is a clearance error that causes the meshing due to the play between the sprocket and the roller chain, which is explained in the prior art, to be reversed between when the gear is stopped and when the gear is stopped from the reverse. At the same time, an error corresponding to backlash is mixed. There has been a problem that the errors due to the above three reasons are accumulated, the vehicle stops at a position deviated from the target stop position, and the accuracy of die height adjustment decreases.

[0005]

In order to solve the above-mentioned problems and to improve the die height adjustment accuracy, in the method of the present invention, the link housing and the fixed platen are connected by a plurality of tie bars, and the tie bars are connected together. As a guide, a die casting machine for arranging a movable plate so as to reciprocate between the link housing and a fixed plate, clamping the movable plate via a toggle mechanism, and adjusting the die height by moving the link housing. In order to adjust the die height by advancing or retreating the link housing by a predetermined distance in step 1, the link housing is once started and the stop command is issued at an arbitrary position after the link housing reaches the steady speed during the backward movement and the backward movement is performed. A position where the limit distance is measured, and then the vehicle is started forward and the backward limit distance and the stop command transmission distance are added to the predetermined distance. It was decided to stop to disseminate a stop command when it came.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 7 show an embodiment of a die casting machine according to a die height adjusting method of the present invention, FIG. 1 is a side view of a die casting machine (when the die is opened), FIG. 2 is a front view of the die casting machine, and FIG. 3 is a die casting machine. 4 is a side view of a die casting machine (when a metal touch), FIG. 5 is a side view of a die casting machine (when a mold is clamped), and FIG.
Is an explanatory diagram showing a procedure of a die height adjusting method when the link housing is moved forward, and FIG. 7 is an explanatory diagram showing a procedure of a die height adjusting method when retracting the link housing.

The structure and operation of the die casting machine are the same as those described in the prior art, and will not be described. The die height adjusting method for a die casting machine according to the present invention performs the adjustment in exactly the same manner when the link housing 1 is moved forward in the direction of the fixed platen 2 by a predetermined distance or retracted by a predetermined distance. That is, when advancing a predetermined distance, as shown in FIG. 6, the initial point P ₀
A stop command is transmitted to the drive device at an arbitrary position (distance A from the initial point P ₀ ) after the drive device is further started backward and reaches the steady speed. Then, the link housing 1 then overruns by a minute distance a due to inertia or the like and stops. In the figure, P ₁ indicates the stop command transmission position, and P ₂ indicates the stop position (reverse limit). After that, the vehicle is started forward to stop at the target forward stop position P ₄ , and the stop command is transmitted at the stop command transmission position P ₃ . The stop command transmission position P ₃ needs to be determined so that the link housing 1 overruns after receiving the stop command and stops exactly at the forward stop position P ₄ .

In order to determine the stop command transmission position P ₃ , the overrun distance a is P ₁ when stopping from the steady speed.
The calculation is performed by focusing on the fact that both P ₂ and P ₃ P ₄ are equal. That is, when it is considered that P ₀ , P ₁ , ... P ₄ are located on the coordinate axis having the 0 point at the leftmost end in FIG. 6, the stop command transmission position P ₃ is equivalent to P ₄ −a. , A = P ₁ −P ₂ and P ₁ = P ₀ −A, the stop command transmission position P ₃ = (P ₄ −P ₀ ) + P ₂
+ A, and the predetermined distance _(P A -P ₀₎ and a retracted limit distance _{P 2}
And the stop command transmission distance A.

In this case, of the above three reasons for the error in the die height setting, the overrun distance a is deviated due to the inertia of the power system described in the second and third reasons, and the play and backlash of the transmission mechanism of the drive device are caused. The error due to the deviation due to is offset and eliminated. In addition, the moving distance A from the initial point P ₀ to the arbitrary stop command transmission position P ₁ is an error due to the delay of the control system (when the stop command actually reaches the drive device after the position sensor detects the position). However, the stop transmission distance is actually A ', which is slightly larger than A, but the stop command transmission distance is A'. Both are offset as well since they are A. Therefore, all the causes of error due to the above three reasons are eliminated.

Even when the die height adjustment is required to retreat from the initial point P ₀ by a predetermined distance, the same procedure is performed. In this case, as shown in FIG. 7, the vehicle starts backward from the initial point P ₀ , issues a stop command at the stop command transmission position P ₅ of the moving distance A, and stops at the reverse limit P ₆ . Thereafter, the forward start, given a stop command in the stop command originating position P ₇ obtained by subtracting a predetermined distance P ₀ -P ₈ than the sum of the retreat limit distance P ₆ and the moving distance A, moves the overrun distance a After that, the vehicle stops at the target stop position P ₈ .

The die height adjusting method for the die casting machine according to the present invention described above not only eliminates the error due to the overrun due to the inertia of the link housing and the power system, the play due to the power system, and the clearance due to the meshing.
Errors due to overrun due to the delay of the control system, which is a minute amount higher than these, are also eliminated. Therefore, the die height adjustment accuracy is dramatically improved. Although the method of the present invention is described as a die height adjusting method for a die casting machine, it can be applied to an injection molding machine as a matter of course.

[0012]

As described above, in the method of the present invention, the accuracy of the die height adjustment by the movement of the link housing is improved, so that the setting accuracy of the mold clamping force is improved and the quality of the product is improved.

[Brief description of drawings]

FIG. 1 is a side view of a die casting machine (when a mold is opened) according to an embodiment of the present invention.

FIG. 2 is a front view of a die casting machine according to an embodiment of the present invention.

FIG. 3 is a side view of a main part of the die casting machine according to the embodiment of the present invention.

FIG. 4 is a side view of a die casting machine (during metal touch) according to an embodiment of the present invention.

FIG. 5 is a side view of a die casting machine (during mold clamping) according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a procedure of a die height adjusting method when advancing the link housing.

FIG. 7 is an explanatory diagram showing a procedure of a die height adjusting method when retracting the link housing.

[Explanation of symbols]

1 link housing 2 fixed plate 2a fixed mold 3 tie bar 4 movable plate 4a movable mold 5 toggle mechanism 6 link 7 link 8 link 9 crosshead 10 mold clamping cylinder 11 piston rod 12 tightening nut 13 chain wheel 14 die height adjusting motor 15 roller chain 16 Limit switch 17 Stand 18 Scale (position) 20 Position sensor 30 Magnetic scale A Moving distance a Overrun distance H Die height (die thickness) H ₀ Previous die height P ₀ Initial point P ₁ , P ₅ Stop command transmission position P ₂ , P ₆ Reverse limit position P ₃ , P ₇ Stop command transmission position P ₄ , P ₈ Target stop position

Claims (1)

[Claims] 1. A link housing and a fixed platen are connected by a plurality of tie bars, and a movable plate is reciprocally disposed between the link housing and the fixed plate with the tie bar as a guide. In a die casting machine that adjusts the die height by clamping the mold via a toggle mechanism and moving the link housing, when the die height is adjusted by advancing or retreating the link housing by a predetermined distance, the die housing is moved backward to start the link housing. Sends a stop command at an arbitrary position after reaching the steady speed during backward movement, measures the backward limit distance, and then starts forward and adds the backward limit distance and the stop instruction transmission distance to the predetermined distance. A die height adjusting method for a die casting machine that sends a stop command and stops when it reaches the specified position.