JP2826004B2 - Squeeze die casting method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squeeze die casting method and apparatus, and more particularly to an effective technique applied to a squeeze die casting method and apparatus for pressurizing molten metal in a cavity with a squeeze pin.

[0002]

2. Description of the Related Art A squeeze die casting apparatus of this type is disclosed, for example, in Japanese Patent Application Laid-Open No. 61-86060.

That is, in this squeeze die casting apparatus, pressure is applied to the molten metal during solidification by moving a squeeze pin in a pin hole of a movable mold by an extrusion cylinder and forcing the molten metal in the pin hole into a cavity. In this way, casting defects such as shrinkage cavities are prevented, and after the mold is opened, the extrusion pin is moved by an extrusion cylinder to extrude the work.

[0004]

However, in the conventional squeeze die casting apparatus described above, since the squeeze stroke is controlled by the stopper, the squeeze stroke cannot be controlled, and it is difficult to change the squeeze stroke. there were.

An object of the present invention is to provide a squeeze die casting method and apparatus which enable control of a squeeze stroke and facilitate change of a squeeze stroke for various works having different shapes and materials. is there.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0007]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, in the squeeze die casting method of the present invention, the position of a squeeze plate for fixing the squeeze pin is detected, and the squeeze stroke of the squeeze pin is controlled based on the detected detection signal. The end of the squeeze stroke of the squeeze pin is set so that a minute clearance is interposed between the extrusion plate for fixing the squeeze plate and the squeeze plate, and the squeeze operation is performed. Further, the squeeze die casting apparatus of the present invention is an extrusion pin and a squeeze pin that slide in a pin hole of a movable mold, an extrusion plate and a squeeze plate for fixing the extrusion pin and the squeeze pin, and moving the squeeze plate. An extruding cylinder that abuts against the extruding plate and moves together with the extruding plate; a position sensor that detects a position of the squeezing plate; and a squeezing stroke that controls a squeezing stroke of the squeeze pin based on a detection signal from the position sensor. At the end, a squeeze control means for controlling the squeezing operation by setting the end of the squeeze stroke of the squeeze pin so as to interpose a minute clearance between the extrusion plate and the squeeze plate. It is.

[0009]

In the above means, when performing squeeze die casting, the position of the squeeze plate for fixing the squeeze pin is detected, and the squeeze stroke is controlled based on the detected detection signal. A minute clearance is interposed between the plate and the squeeze plate.

As described above, the squeeze stroke can be controlled, and various works having different shapes and materials can be controlled.
The squeeze stroke can be easily changed.

Further, since a minute clearance is interposed between the squeeze plate and the extruding plate at the end of the squeezing, the squeeze pin alone is not protruded at the time of the extruding, so that the work is not deformed.

Further, since a minute clearance is interposed between the squeeze plate and the extruding plate at the end of the squeeze, the molten metal in the pin hole of the squeeze pin after the end of the squeeze is made to have a very small capacity, and the work to be extruded is deformed. Can be kept within an allowable range.

[0013]

FIG. 1 is a cross-sectional view of a squeeze die casting apparatus according to an embodiment of the present invention, showing a state of matching, FIG. 2 is a cross-sectional view of a squeeze die casting apparatus showing a squeezing start state after filling a molten metal, and FIG. 1 is a sectional view showing a rotary encoder, and FIG. 4 is a circuit diagram showing a squeeze hydraulic control unit.

The squeeze die casting apparatus in this embodiment has a machine base 1, a fixed die plate 2 is provided on the machine base 1, and a movable die plate 3 facing the fixed die plate 2 is guided by a tie bar 4. It has a structure that can be moved by a cylinder not shown.

A fixed mold 5 is provided on the fixed die plate 2, and a movable mold 7 is provided on the movable die plate 3 via a die base 6. A cavity 8 is formed therein, and an injection sleeve 9 for pouring molten metal into the cavity 8 is provided through the fixed die plate 2. A plunger 10 is slid on the inner peripheral surface of the injection sleeve 9, and is provided on the outer peripheral surface. The pouring port 11 is opened.

At the left end of the movable mold 7, an extruding plate 13 is movably provided via a guide pin 12, and a return pin 14 and an extruding pin 15 are provided on the extruding plate 13.
Is fixed and extends into the pin holes 17a and 17b in the movable mold 7, and the return pin 14 is
The has a function to return to the position of the squeeze stroke end S _2, ejector pin 15 has a function to release the workpiece W in the cavity 8 is extruded after mold opening.

A pair of upper and lower extruding rods 32 are movably penetrated through the movable die plate 3, and a machine extruding plate 16 is provided at the left end of the pair of extruding rods 32, and a squeeze plate 33 is provided at the right end. A squeeze pin 34 is fixed to the squeeze plate 33 and extends into the pin hole 17c of the movable mold 7, and the squeeze pin 34 is
By moving the molten metal in the pin hole 17c into the cavity 8 by pressurizing the molten metal in the cavity 7c, pressure is applied to the molten metal during solidification to prevent the occurrence of casting defects such as shrinkage cavities.

An extruding cylinder 26 is connected to the machine extruding plate 16, and the extruding cylinder 26 moves the squeeze plate 33 and abuts the extruding plate 13 to move the extruding plate 13.

The pull-out rod 18 fixed to the pushing plate 13 has a function of slidably penetrating the squeeze plate 33 and pulling the pushing plate 13 back.

A rotary encoder 22 is attached to the movable die plate 3 via a bracket 21, and a rotary shaft 35 of the rotary encoder 22 is attached to a pinion 2.
0 is directly connected to the rack 19 which meshes with the pinion 20.
Is provided on the machine extrusion plate 16, and the machine extrusion plate 16
Squeeze plate 33
Is detected.

[0021] The controls squeeze stroke L based on the detection signal from the rotary encoder 22, the end S ₂ squeeze stroke L, squeeze pins as to interpose a clearance G of minute between the pushing plate 13 and the squeeze plate 33 A squeeze hydraulic control unit 23 (squeeze control means) for setting a squeeze stroke and controlling a squeeze operation is provided.

That is, the squeeze hydraulic control unit 23 is connected to the secondary side of a three-position spring center type extrusion cylinder control valve 25 to which a hydraulic pump 24 is connected. First directional control valve 28a connected to chamber 27a
And the squeeze pressure control valve 29 and the extrusion cylinder 26
A second directional control valve 28b and an electromagnetic proportional flow control valve 30 connected to the rod-side cylinder chamber 27b.

The squeeze pressure control valve 29 has a function of controlling the squeeze pressure to a set pressure, and the electromagnetic proportional flow control valve 30 has a function of controlling the flow in proportion to the current of the proportional solenoid 31.

Next, the operation of this embodiment will be described.

FIG. 5 is a cross-sectional view showing the squeezing die casting apparatus in a squeezed state, FIG. 6 is a cross-sectional view showing the mold opening and the work extruding state of the squeeze die casting apparatus, and FIG. It is.

When the squeeze die casting is performed in the above-described configuration, first, the graph of FIG. 7 shows a relationship between the squeeze pressure and the squeeze stroke L. This relationship is obtained from an experimental result, and shows the relationship between casting defects such as shrinkage cavities. The squeeze pressure control valve 29
Adjust with.

Further, a squeeze stroke L corresponding to the set pressure is selected, and its start end S ₁ and end S ₂ are selected.
Is the reference position.

Next, the squeeze plate 33 is disposed at a position from the squeeze plate retreat limit position S ₀ of the mold matching state to the start end S ₁ of the squeeze stroke, and the cavity 8 is filled with molten metal.

After filling the molten metal, the squeeze pressure of the oil supplied to the head side cylinder chamber 27a is controlled to a set pressure by a squeeze pressure control valve 29, and the rod side cylinder chamber 27 is controlled.
The amount of oil discharged from b is controlled to a set flow rate by the electromagnetic proportional flow control valve 30, and a squeeze operation is started.

When the squeeze plate 33 reaches the end S ₂ of the squeeze stroke L, the squeeze plate 33
The squeezing operation is terminated based on this detection signal. At this time, a minute clearance G (within 0.3 mm) is interposed between the squeezing plate 33 and the pushing plate 13.

The squeeze operation allows the squeeze pin 3
4 is moved in the pin hole 17c of the movable mold 7 to
The molten metal 7c is pressed into the cavity 8 to apply pressure to the molten metal during solidification, thereby preventing casting defects such as shrinkage cavities.

When the molten metal is solidified, the mold is opened, and the squeeze plate 33 is brought into contact with the extruding plate 13 and moved together with the extruding plate 13 so that the extruding pin 15 and the squeezing pin 3 are moved.
4 is projected from the pin holes 17b and 17c to extrude the work W and release the mold.

As described above, the squeeze stroke L can be controlled, and the squeeze stroke can be easily changed for various works W having different shapes and materials.

Further, since the minute clearance G is interposed between the squeeze plate 33 and the push plate 13 at the end of the squeeze, the work W is not deformed by projecting only the squeeze pin 34 at the time of push.

Further, since a small clearance G is interposed between the squeeze plate 33 and the extruding plate 13 at the end of the squeeze, the squeeze pin 34 after the squeeze is completed.
The deformation of the extruded work W can be kept within an allowable range by making the molten metal in the pin hole 17c a very small volume.

Although the invention made by the inventor has been specifically described based on the embodiments, the invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say.

For example, in the above embodiment, the case where a rotary encoder is used as the position sensor has been described. However, the present invention is not limited to this, and a linear scale can be used as the position sensor.

[0038]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) Since the squeeze die casting method and apparatus for detecting the position of the squeeze plate for fixing the squeeze pin and controlling the squeeze stroke based on the detected detection signal, the squeeze stroke can be controlled.
At the end of the squeeze stroke, a minute clearance can be interposed between the squeeze plate and the extrusion plate that fixes the extrusion pin.

(2) By controlling the squeeze stroke, it is possible to easily change the squeeze stroke for various works having different shapes and materials.

(3) At the end of the squeeze, a minute clearance is interposed between the extruded plate and the squeeze plate, so that only the squeeze pins are protruded at the time of the extruded member so that the work is not deformed.

(4) At the end of the squeeze, a minute clearance is interposed between the extruded plate and the squeeze plate so that the molten metal in the squeeze hole after the end of the squeeze is made to have a very small volume, and deformation of the extruded work is allowed. You can stop within the range.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a mold matching state of a squeeze die casting apparatus according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a squeeze start state after filling the molten metal of the squeeze die casting apparatus.

FIG. 3 is a sectional view showing the rotary encoder of FIG. 1;

FIG. 4 is a circuit diagram showing a squeeze hydraulic control unit.

FIG. 5 is a cross-sectional view showing a squeezing end state of the squeeze die casting apparatus.

FIG. 6 is a cross-sectional view showing a mold open state and a work extruded state of the squeeze die casting apparatus.

FIG. 7 is a graph showing a relationship between a squeeze pressure and a squeeze stroke.

[Explanation of symbols]

Reference Signs List 1 machine base 2 fixed die plate 3 movable die plate 4 tie bar 5 fixed mold 6 die base 7 movable mold 8 cavity 9 injection sleeve 10 plunger 11 pouring port 12 guide pin 13 extrusion plate 14 return pin 15 extrusion pin 16 machine extrusion plate 17a Pin hole 17b Pin hole 17c Pin hole 18 Retraction rod 19 Rack 20 Pinion 21 Bracket 22 Rotary encoder 23 Squeeze hydraulic control unit (squeeze control means) 24 Hydraulic pump 25 Extrusion cylinder control valve 26 Extrusion cylinder 27a Head side cylinder chamber 27b Rod side cylinder Chamber 28a First directional control valve 28b Second directional control valve 29 Squeeze pressure control valve 30 Electromagnetic proportional flow control valve 31 Proportional solenoid 32 Push rod 33 Squeeze plate 4 squeeze pin 35 rotation axis L squeeze stroke S ₀ squeeze plate retracted limit position S ₁ squeeze stroke start end S ₂ squeeze stroke end G clearance W workpiece

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroaki Takatsu 1914-2 Ojihara, Minago-cho, Gunma-gun, Gunma Prefecture Inside the East Japan Die Casting Industry Co., Ltd. (56) References JP-A-3-270920 (JP, A) 61-167258 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 17/22 B22D 17/32 B29C 45/56 B29C 45/76

Claims (2)

(57) [Claims] 1. A detects the position of the squeeze plate for fixing the squeeze pin, the rake based on the detected detection signal
Controls squeeze stroke Zupin, the squeeze stroke end, so that makes intervention clearance small between the extrusion plate for fixing the ejector pin and the scan <br/> quiz plate
Set the end of the squeeze stroke of the squeeze pin
And performing a squeezing operation . Wherein the ejector pin and the squeeze pin slides in the pin hole of the movable mold, and the extrusion plate and a squeeze plate for fixing the ejector pin and squeeze pin to move the squeeze plate, against the said pushing plate the extrusion cylinder which moves together with the extruded <br/> and plate against, a position sensor for detecting the position of the squeeze plate, to control the squeeze stroke of the squeeze pin based on a detection signal from the position sensor, squeeze stroke at the end, a small clearance between the push <br/> pulling plate and the squeeze plate
Squeeze stroke of the squeeze pin to intervene
And a squeeze control means for controlling the squeeze operation by setting the end of the squeeze operation .