JPH11320070A - Hot-water supply apparatus for die casting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently supply a specified amt. of molten metal to an injection sleeve without the occurrence of inclusion of air into the molten metal. SOLUTION: The molten metal in a molten metal passage 45 is introduced into a molten metal housing space 73 while pushing up a check valve 77 in a molten metal reservoir section 19 by the downward actuation of a plunger 21 in a pump section 17. The molten metal is also introduced into outlet piping 93. When the actuation of the plunger 21 stops, the check valve 77 descends to a closed state and the molten metal in the molten metal housing space 73 and the outlet piping 93 is assured as it is and in this state, the molten metal is supplied to an injection plunger 3 again by the actuation of the plunger 21 on the basis of the molten metal surface A or molten metal surface B in the outlet piping 93.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply apparatus for a die casting machine for supplying a molten metal to an injection sleeve communicating with a cavity of a mold.

[0002]

2. Description of the Related Art In a hot water supply device for a die casting machine,
When the molten metal is supplied from the heat retaining furnace storing the molten metal to the injection sleeve communicating with the cavity of the mold, the following method is employed.

(1) A predetermined amount of molten metal is drawn by an automatic machine using a ladle and poured into an injection sleeve.

(2) A predetermined amount of molten metal is fed into the injection sleeve by operating the electromagnetic pump for a predetermined time.

(3) The level of the molten metal in the heat-retaining furnace is measured, and a predetermined amount of molten metal is fed into the injection sleeve by a plunger-type hot water supply pump based on the level of the molten metal.

[0006]

However, in the above method (1), when pouring with a ladle, the entrapment of air into the molten metal is unavoidable, and the surface of the molten metal is exposed to air and oxidation of the surface occurs. There are drawbacks such as occurrence.

In the method (2) using an electromagnetic pump, since the molten metal is conveyed in the pipe, the problem of using the above-mentioned ladle is solved. Since the operation is performed during the operation time of the pump, the electromagnetic characteristics of the molten metal determine its hot water supply amount, and the hot water supply amount also varies due to a change in passage resistance in the pipe due to solidification of the molten metal. It is difficult to supply to the injection sleeve.

In the method (3) using a plunger type hot water supply pump, the molten metal is conveyed through the pipe, as in the case of the electromagnetic pump hot water supply. Since it is located at the position, the amount of molten metal corresponding to the height difference also needs to be pumped with reference to the surface of the insulated furnace. In addition, the difference in the amount of molten metal tends to be larger than the effective amount of hot water supplied into the injection sleeve. Therefore, it is necessary to set a large amount of waste water including waste, and the pump capacity is increased accordingly. This leads to an increase in the size and cost of the pump. In addition, when the amount of hot water supplied increases, the amount of molten metal returned in the return step of the plunger also increases correspondingly, and air bubbles are easily generated accordingly.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an injection sleeve capable of always supplying a fixed amount of molten metal to the injection sleeve without involving large waste, without causing entrainment of air into the molten metal.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, a plunger which moves in a sleeve capable of introducing a molten metal is provided in a molten metal furnace in which the molten metal is accommodated. A pump portion and a molten metal pool portion for introducing the molten metal discharged from the pump portion through a molten metal passage are provided in a state of being immersed in the molten metal, and the molten metal pool portion is provided with the molten metal passage. A check valve for preventing the backflow of the molten metal from the molten metal pool to the pump section at the molten metal inlet port of the molten metal introduced through the A metal surface measuring mechanism connected to the injection sleeve via an outlet pipe located above the metal surface of the metal and measuring the metal surface of the molten metal introduced into the outlet pipe through the molten metal pool; When hot water to blanking, certain melt-surface height measured by the melt-surface measuring mechanism as a for operating the plunger of the pump unit as a reference.

According to the hot water supply device for a die casting machine having such a configuration, the metal melt in the molten metal passage flows into the molten metal pool through the check valve of the molten metal pool by the plunger operation of the pump. Also flows into the outlet pipe. The molten metal level measuring mechanism measures that the molten metal level of the molten metal that has flowed into the outlet pipe has reached a predetermined height position, and thereafter the injection is performed by operating the plunger of the pump unit based on the measured position. A predetermined amount of molten metal is supplied into the sleeve.

According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the melt level measuring mechanism is provided with a float in a measuring pipe extending upwardly in communication with the molten metal pool. And a rod portion which is always urged upward by a spring, and which is a portion to be measured which protrudes upward through a through hole at an upper end of the pipe for measurement, and which is an upper inner surface of the pipe for measurement. And a float drive unit for moving the rod part upward so as to press the through hole so as to seal the through hole, and measures a vertical position of the float.

According to the above configuration, the molten metal flows into the measurement pipe with the flow of the molten metal into the outlet pipe.
Due to the rise of the molten metal surface due to the inflow of the molten metal, the float rises with a spring against the force of gravity against the spring,
The rising position of the float is measured by measuring the rod, and the measured value is the molten metal surface position in the outlet pipe. In addition, by moving the rod part upward by the float drive unit and making it closely adhere to the upper inner surface of the measurement pipe, the molten metal filled in the measurement pipe leaks out of the gap between the rod part and the through hole to the outside. Is avoided.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a hot water supply device of a die casting machine showing an embodiment of the present invention. This hot water supply apparatus feeds a molten metal 1 made of an aluminum alloy or the like in a molten metal furnace to an injection sleeve 3 on a die casting machine side. The molten metal supplied into the injection sleeve 3 is operated by an injection hydraulic cylinder 5. As a result, it is fed into the cavity 15 between the pair of molds 11 and 13 fixed to the die plates 7 and 9, respectively, and is subjected to pressure casting.

The hot water supply apparatus has a pump 17 for pumping the molten metal 1 and a pool 19 for storing the molten metal pumped by the pump 17, and these are immersed in the molten metal 1. It is provided in the state where it was set.

The pump section 17 has a structure in which the plunger 21 moves vertically in the sleeve 23 in the figure. The upper part of the plunger 21 is extended upward from the molten metal surface L of the molten metal 1 and the upper end thereof. It is connected to a cylinder rod 29 of a hydraulic servo cylinder 27 via a connection bar 25. In the hydraulic servo cylinder 27, the cylinder rod 29 can be moved at a variable speed by a controller command, and the plunger 21 is lowered by the operation of the cylinder rod 29, whereby the molten metal is pressure-fed to the molten metal pool portion 19 side. The hydraulic servo cylinder 27 secures a position repeatability of 0.1 mm, and the stroke S of the plunger 21 is 100 mm.
In this case, the error is 0.1%, which can be said to be extremely high precision.

The sleeve 23 is fitted into a casing 31 made of a casting material from above in the figure, and the upper end is fixed by a sleeve retainer 33. The casing 31 is fixed to a frame 35 disposed above the molten metal surface L by bolts 37. A support frame 39 is provided on the upper portion of the frame 35 so as to surround the connecting rod 25, and the hydraulic servo cylinder 2 is mounted on the support frame 39.
7 is fixedly supported. A heater 41 whose upper end is supported by the frame 35 and protrudes downward is embedded in the upper end of the casing 31 to heat the casing 31.

The casing 31 has, below the sleeve 23, a stroke space 43 in which the plunger 21 moves up and down in the range of the stroke S, and a molten metal passage 45 communicating with the stroke space 43. The molten metal passage 45 has a horizontal portion 45 a and a vertical portion 45 b continuous with the left end of the horizontal portion 45 a, and the upper end of the vertical portion 45 b is connected to the molten metal reservoir 19.

At a portion of the horizontal portion 45a protruding from the side opposite to the vertical portion 45b, a communication hole 47 is formed which opens into the molten metal 1 in the melting furnace, and serves as an on-off valve for opening and closing the communication hole 47 from above. Is provided so as to be vertically movable. Around the communication hole 47, a makeup receiver 5
The communication hole 47 is shut off when the makeup piston 49 comes into contact with the upper surface of the makeup receiver 51. A make guide 53 for guiding the vertical movement of the make piston 49 is fitted into the casing 31 above the communication hole 47 from above, and the make guide 53 is attached to the frame 35.
The upper side is fixed by a guide retainer 57 whose upper end is fixed.

The make piston 49 is connected to a cylinder rod 61 of a make cylinder 59 via a rod portion 55. The make cylinder 59 is fixed on a spring case 65 fixed to the upper part of the frame 35 via a flange member 63. The spring case 65 houses a spring 69 interposed between the flange member 63 and a spring receiver 67 fixed to the cylinder rod 61.

The spring 69 urges the cylinder rod 61 upward, and the urging force raises the make piston 49 to open the communication hole 47 as shown in FIG. During the hot water supply operation in which the plunger 21 of the pump section 17 moves down, the make cylinder 59 operates to lower the make piston 49 and close the communication hole 47.

The molten metal pool 19 has a molten metal storage space 73 in a molten metal pipe 71, and a molten metal inlet 75 of the molten metal storage space 73 is provided with a check valve 77 which can move up and down in the figure. . A valve receiver 79 is provided around the molten metal inlet 75, and the check valve 77 is separated from the valve receiver 79 when the molten metal is sent through the molten metal passage 45 by the operation of the pump unit 17. When the lowering operation of the plunger 21 is stopped when the valve is opened, the conical surface at the lower end abuts on the valve receiver 79 and the valve is closed as shown in FIG.

A cylindrical valve guide 81 for guiding the up-down operation of the check valve 77 is fitted into the molten metal pipe 71 of the molten metal inlet portion 75 from above, and the valve guide 81 is further fitted from above. The cover 83 is fixed in a sealed state.

The guide cover 83 is attached to the upper frame 35.
The holding rod 87 is fixedly supported by a holding rod 87 extending downward from the holding plate 87, and an upper end side of the holding rod 87 is fixed to a holding plate 89 provided on the upper surface of the frame 35.

A molten metal outlet 91 is formed above the left end of the molten metal accommodating space 73 in FIG. 1, and one end of an outlet pipe 93 is connected to the molten metal outlet 91 via a pipe receiver 95. . The outlet pipe 93 is bent in a crank shape, and an upper end portion thereof is in contact with an opening 3 a provided at a lower portion of the injection sleeve 3 via an outlet ring 97 constituting a heat insulating material.
A heater 99 is provided around the outlet pipe 93 to keep the molten metal in the outlet pipe 93 warm.

The outlet pipe 93 is fixedly supported by a holding rod 101 extending downward from the upper frame 35, and the upper end of the holding rod 101 is fixed to a holding plate 103 installed on the upper surface of the frame 35. Have been.

The molten metal pipe 71 is formed such that the circumference of the outlet pipe 93 and the circumference of the valve guide 81 are formed on the surface L of the molten metal 1.
A heat insulating cover 105 is attached to the protrusion and the upper surface of the guide cover 83 to insulate the molten metal in the molten metal pipe 71.

Parts that the metal melt contacts, such as the melt pipe 71, the outlet pipe 93, and the casing 31, are provided with an aluminum-resistant melt lining material.

On the right side of the check valve 77 in the molten metal pipe 71 in FIG. is set up. The float 107 is vertically movably housed in a float support 111 serving as a cylindrical measurement pipe extending in the vertical direction, and a lower end of the float support 111 is fitted in an upper opening of the melt pipe 71. 113. The float support 111 has a small diameter on the lower side from the portion where the float 107 moves, and the upper end of the small diameter portion is the lower limit position D of the float 107.

As shown in an enlarged view in FIG. 2, the float 107 has an upwardly extending rod portion 107a as a portion to be measured, and the rod portion 107a closes an upper end opening of the float support 111. The projection 115 protrudes upward through the through-hole 115a. The periphery of the float support 111 from the molten metal surface L to the upper part is covered with a cover 117 having an open lower end, and the cover 117 is floated by a support retainer 121 whose upper end is bent into a crank shape via an insulating ring 119. Support 1
11 and supported. The cover retainer 121
The lower fixing portion 121 a is fixed to the upper surface of the frame 35. A heater 123 is attached to the cover 117 from the vicinity of the frame 35 to the upper side thereof to keep the molten metal inside the float support 111 warm.

The rod portion 107a of the float 107 protrudes upward through the heat insulating ring 119 and the cover retainer 121. The protruding upper end T is measured by a position measuring device (not shown), and the measured value is obtained. , The reference level at the start of hot water supply to the injection sleeve 3.

An upper portion of a float guide plate 127 bent in a crank shape is fixed near an upper end portion of the rod portion 107a, and a lower portion of the float guide plate 127 has a spring bar 129 extending upward from the frame 35.
It is mounted so that it can move up and down. A spring 131 that urges the float guide plate 127 upward together with the float 107 is interposed between the attachment portion of the float guide plate 127 to the spring bar 129 and the fixing portion 121a of the support retainer 121 on the frame 35. I have. The urging force of the spring 131 is
Is set smaller than the gravity value.

Above the float guide plate 127, the float cylinder 1 as a float drive unit attached to a mounting bracket 133 projecting sideways from the support frame 39
35 are installed. The cylinder rod 137 of the float cylinder 135 projects downward and is connected to the float guide plate 127 so as to be vertically movable.

At the tip (lower end) of the cylinder rod 137, a flange portion 137a is formed.
By the upward movement of the 37, the float guide plate 127 locked by the flange portion 137a is forcibly moved to the raising limit position U of the float 107 together with the float 107. In a state where the float 107 has moved to the raising limit position U, the upper end of the float 107 is
15 and the through hole 115a is closed.

The molten metal level detection mechanism 109 in the molten metal pipe 71
Further, a valve piston 139 as a molten metal relief valve is provided on the right side in FIG. The valve piston 139 is
A communication passage 141 that communicates between the molten metal storage space 73 and the outside of the molten metal furnace in which the molten metal 1 is stored is opened and shut off, and is guided by a valve guide 143 fitted into the molten metal pipe 71 above the communication passage 141. It can be moved up and down. The valve piston 139 enters the annular valve receiver 145 fitted into the communication path 141 to shut off the communication path 141 as shown in FIG. Open.

The upper part of the valve piston 139 is
It is extended to the vicinity, and a flange member 147 is mounted on a frame 35 around the vicinity. A valve guide retainer 148 is interposed between the flange member 147 and the valve guide 143, and the valve guide 143 is fixed.

A support case 149 is fixed on the flange member 147, and a valve cylinder 151 for moving the valve piston 139 up and down is mounted on the support case 149. The cylinder rod 153 of the valve cylinder 151 is
It extends downward, and its tip is fixed to the upper end of the valve piston 139. A flange 153a is formed substantially at the center of the cylinder rod 153 in the up-down direction. The valve spring 159 for urging the valve upward is interposed.

At the time of hot water supply operation in which the plunger 21 of the pump section 17 is lowered, the valve cylinder 151 is operated to lower the valve piston 139 as shown in the drawing, and the communication path 141 is shut off. When opening the communication passage 141, the valve cylinder 1
The operation of 51 is stopped, and the valve piston 139 is raised by the action of the valve spring 159. The rising end position of the valve piston 139 is determined by the flange member 1 together with the support case 149.
It is determined by the regulating member 161 fixed to 47.

Next, the operation of the hot water supply device of the die casting machine configured as described above will be described. As shown in FIG. 1, when the make piston 49 opens the communication hole 47, the molten metal 1 in the melting furnace flows into the molten metal passage 45 through the communication hole 47 and becomes full. In this state,
When the make piston 49 is lowered by the operation of the make cylinder 59, the make piston 49 comes into contact with the make receiver 51 and the communication hole 47 is shut off.

When the plunger 21 is lowered by the operation of the hydraulic servo cylinder 27 in a state where the communication hole 47 is shut off, the molten metal filled in the molten metal passage 45 moves the check valve 77 in the molten metal pool 19 to the check valve 77. By pushing up, the molten metal inlet portion 75 is opened, and the molten metal is supplied to the molten metal storage space 73. At this time, the valve piston 139 is
51 is in a state where the communication path 141 is shut off.

The molten metal supplied to the molten metal storage space 73 is further supplied to the outlet pipe 93 and the float support 111.
When the molten metal in the outlet pipe 93 and the float support 111 reaches, for example, a predetermined level A or level B, the operation of supplying the molten metal by the hydraulic servo cylinder 27 is stopped. . The supply of the molten metal by the hydraulic servo cylinder 27 is stopped by a position measuring device which measures the rising position of the float 107 accompanying the rise of the molten metal level, and based on this measurement signal. When the supply operation of the molten metal to the molten metal accommodating space 73 is stopped, the check valve 77 is lowered to close the molten metal inlet portion 75, and the position of the molten metal surface A or the molten metal surface B is secured as it is.

If the plunger 21 does not reach the set level A or level B in one lowering operation, the make piston 49 is raised by operating the make cylinder 59 to open the communication hole 47 and the plunger 21. Is raised to introduce and fill a new molten metal 1 into the molten metal passage 45. Thereafter, the make piston 49 is shut off and the plunger 21 is lowered again, and
The molten metal in 5 is sent to the molten metal accommodating space 73 so as to have a predetermined level A or level B.

When the level of the molten metal in the outlet pipe 93 reaches a predetermined position (the level A, the level B, etc.), the plunger 21 is raised after the make piston 49 is opened, and the plunger 21 is moved into the molten metal passage 45. The molten metal 1 is introduced and filled. Thereafter, make piston 49 is shut off, plunger 21 is lowered again, and the operation shifts to a hot water supply operation to injection sleeve 3. During this hot water supply operation, the molten metal in the molten metal passage 45 pushes up the check valve 77 and flows into the molten metal accommodating space 73, so that the level of the molten metal gradually rises in the outlet pipe 93 and the molten metal in the injection sleeve 3. Will be supplied. The molten metal supplied into the injection sleeve 3 is supplied into the cavity 15 by the operation of the injection hydraulic cylinder 5 and cast under pressure, as described above.

When the molten metal is supplied to the injection sleeve 3, when the upper end of the float 107 reaches a height position almost in contact with the float receiver 115, the float cylinder 1
By operating 35, the cylinder rod 137 is raised.
As the cylinder rod 137 rises, the flange portion 137a at the tip of the cylinder rod 137 is locked to the float guide plate 127, the float 107 is raised, and the upper end thereof is float receiver 115.
In close contact. Thereby, even if the molten metal is filled in the float support 111, the rod portion 10 of this molten metal is
Leakage to the outside from the gap between 7a and float receiver 115 is minimized. When a slight leak occurs, the molten metal 1 is returned to the molten metal furnace containing the molten metal 1 through the inside of the cover 117.

The hot water supply amount (the actual discharge amount as a pump) QT is determined in accordance with the descending amount of the plunger 21. When the hot water supply amount QT is, for example,
The volume required for hot water supply in the injection sleeve 3 itself is QA,
Outlet piping 9 from the molten metal surface A to the opening 3a of the injection sleeve 3
Assuming that the volume inside 3 is QB and the volume above the surface A in the float support 111 is QC, QT = QA + QB +
It is represented by QC. Here, QB and QC are assumed to be sufficiently smaller than the value of QT. In particular, the value of QC is
A value much smaller than QB is assumed.

As described above, since the reference level at the start of hot water supply to the injection sleeve 3 is set in the outlet pipe 93, the actual discharge amount at the time of hot water supply by the plunger 21 can be reduced by the conventional method. Since the amount of QB is smaller than in the case where the surface L is used as a reference, it is possible to supply a fixed amount of molten metal to the injection sleeve 3 without including large waste. Since the substantial discharge amount by the pump unit 17 is small, the stroke amount of the plunger 21 is small, the pump itself can be downsized, and the cost can be reduced accordingly.

Also, this method uses the molten metal 1 in a molten metal furnace.
Is supplied to the injection sleeve 3 through the piping, so that the molten metal does not come into contact with air, and surface oxidation of the molten metal is also avoided. Further, at the time of the return operation in which the plunger 21 moves up, the make piston 49 is opened,
Since the molten metal 1 is replenished into the molten metal passage 45, generation of bubbles in the molten metal passage 45 is avoided.

After the molten metal in the injection sleeve 3 is cast under pressure, the valve piston 139 is opened to open the molten metal accommodation space 7.
3 is released into the furnace and the float cylinder 135 is actuated to release the cylinder rod 137.
To release the lock on the float guide plate 127. As a result, the level of the molten metal in the outlet pipe 93 and the float support 111 decreases, and the float 107 also descends as the level of the molten metal decreases. Then, the position of the molten metal surface A at the start of hot water supply is detected by measuring the upper end portion T of the float 107 with a position measuring device.
Close 9. As a result, the hot water level A at the start of hot water supply is secured, and the next hot water supply operation is executed by lowering the plunger 21 again from the upper limit position. When moving the plunger 21 to the upper limit position, the make piston 49
Release.

At the start of hot water supply, the hot water level in the outlet pipe 93 is
Since the same height can be repeatedly set as described above, a stable cast product can be obtained. In addition, the molten metal surface can be freely set between the lower limit position D and the upper limit position U of the float 107, and the hot water supply can be started based on the set position.

In the above embodiment, the case where an aluminum alloy is used as the molten metal is assumed, but the present invention is also applicable when a magnesium alloy is used.

[0052]

As described above, according to the first aspect of the present invention, the molten metal supplied through the check valve into the molten metal pool and the outlet pipe is a molten metal furnace containing the molten metal. The hot water is supplied to the injection sleeve by the plunger operation of the pump part based on the hot water level measured by the hot water level measuring mechanism in the outlet pipe located above the hot water level in the inside.
Compared with hot water supply based on the surface of the molten metal in the furnace, the amount of plunger discharge can be reduced without including large waste, the capacity of the pump section can be reduced, and the overall device can be downsized and cost reduced. it can.

According to the second aspect of the present invention, since the float whose rising position is measured in the measuring pipe is provided with an auxiliary force against the gravity by the spring, the float level is more accurately indicated. In addition, since the float drive unit is provided to move the rod part upward and bring the float into close contact with the upper inner surface of the measurement pipe, the molten metal filled in the measurement pipe has a rod part, a through hole, Can be prevented from leaking out of the gap.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a hot water supply device of a die casting machine showing an embodiment of the present invention.

FIG. 2 is an enlarged detail view showing a part of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molten metal 3 Injection sleeve 17 Pump part 19 Molten pool part 21 Plunger 23 Sleeve 45 Molten passage 75 Molten inlet part 77 Check valve 91 Molten outlet part 93 Outlet piping 107 Float 107a Rod part (measurement part) 109 Hot water level measuring mechanism 111 Float support (measurement piping) 115a Through hole 131 Spring 135 Float cylinder (float drive unit)

Claims (2)

[Claims] 1. A pump section provided with a plunger which moves in a sleeve capable of introducing a molten metal into a molten metal furnace in which the molten metal is accommodated, and the molten metal discharged from the pump section is passed through a molten metal passage. And a molten metal pool portion to be introduced by introducing the molten metal into the molten metal.The molten metal pool portion is provided at a molten metal inlet portion of the molten metal introduced through the molten metal passage, and is provided between the molten metal pool portion and the pump. A check valve for preventing backflow of the molten metal to the section, the molten metal outlet is connected to the injection sleeve via an outlet pipe located above the level of the molten metal in the molten metal furnace, A molten metal level measuring mechanism for measuring the level of the molten metal introduced into the outlet pipe through the molten metal pool is provided, and when the molten metal is supplied to the injection sleeve, the level of the molten metal measured by the molten level measuring mechanism is measured. A hot water supply apparatus for a die casting machine, wherein a plunger of the pump section is operated as a reference. 2. A melt level measuring mechanism, wherein a float is provided in a measuring pipe extending upward in communication with the molten metal pool, and the float is constantly urged upward by a spring, and It has a rod portion that becomes a measured portion that protrudes upward through the through hole at the upper end of the measurement pipe, and presses the float against the upper inner surface of the measurement pipe to seal the through hole. 2. The hot water supply device for a die casting machine according to claim 1, further comprising a float drive unit for moving the float upward, and measuring a vertical position of the float.