JPH07116810A - Water heater - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the foreign substances mixed in the molten metal from adhering to the sealing surface of the valve rod and improve the sealing performance. A hot water supply apparatus, in which a valve seat portion having a hot water outlet as a part of a valve seat sleeve is provided at a lower end of a tip, and a metering valve rod is openably and closably attached to the valve seat portion, the valve seat portion The molten metal seal part on the upper side of the is protruded to the stored molten metal side, the metering valve rod tip part has a hemispherical shape, and an annular groove is provided in the contact part of the metering valve rod tip part with the valve seat part. It has a different configuration.

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 supplying a molten metal such as an aluminum alloy to an injection sleeve of a die casting machine.

[0002]

2. Description of the Related Art Conventionally, when supplying molten metal to an injection sleeve of a die casting machine, for example, Japanese Patent Publication No. 60-2
As described in Japanese Patent No. 5220, a dedicated molten metal holding furnace is arranged near the die casting machine, and the holding furnace measures and conveys the molten metal and pours the molten metal. For measuring / conveying and pouring methods, refer to Japanese Patent Publication No. 60-2522.
As described in Japanese Unexamined Patent Publication No. 0, a method using a ladle and a method of pumping a pipe by an electromagnetic induction pump have been mainstream in practical use.

However, each of these has the following drawbacks. (1) Ladle method: The molten metal is exposed to the outside air and is oxidized, and the temperature is lowered. (2) Electromagnetic induction pump method: Since the molten metal driving force of the electromagnetic pump is weak, the measuring accuracy is poor. Further, in order to increase the molten metal propulsion force, the power supply device becomes large in scale, and the cost and space are deteriorated. Further, the cost also increases for the thermal expansion correspondence and maintenance of the pressure feeding pipe. Further, as a common drawback, a dedicated molten metal holding furnace becomes redundant, which lowers productivity.

The die casting industry is also a representative of workplaces with a bad working environment. The main causes are scattering of the mold release agent and heat dissipation of the molten metal holding furnace and its peripheral equipment. The following are the current problems with molten metal operation. (1) A large-capacity holding furnace is installed on the side of the die casting machine, and moreover, a large amount of heat is dissipated. (2) The mechanism of the hot water supply device is mainly an open type, and a large amount of heat was dissipated to the work place. (3) As a result of (1) and (2), not only the working environment is deteriorated, but also the thermal efficiency is deteriorated. To solve this problem, a small capacity, closed gutter type continuous furnace and a highly accurate metering valve device are required.

By the way, the valve type hot water supply method has not been put to practical use in the die casting industry. The main reasons for this are as follows. (1) The main method was to hold a large amount of molten metal on the side of the die casting machine. As a result, there was no valve mechanism that could withstand the high temperature atmosphere. (2) The measurement accuracy varied due to changes in the properties of the molten metal, and it was not practical.

Therefore, in order to solve these problems, the applicant company of the present invention, for example, like the invention of Japanese Patent Application No. 4-272212 which has not been published at the time of the present application, the tip of the gutter for hot water distribution. A gutter-shaped box that can be sealed is placed between the pouring port of the injection sleeve and the injection sleeve, and the melt of the distribution gutter is changed according to the pouring amount from the metering pouring valve device provided at the lower end of the gutter-shaped box. By the siphon action of the inverted U-shaped tube provided between the tip of the hot water distribution gutter and the rear end of the gutter box, the hot water distribution gutter is automatically moved into the gutter box, As the pouring valve device, a valve seat of the drain port and a valve rod that can be opened and closed with respect to the valve seat are used. Invented a gutter type water heater.

Japanese Patent Application No. 4-272212 has a structure as shown in FIG. In FIG. 4, reference numeral 1 denotes a hot water distribution gutter, which is also called a launder system gutter capable of unmanned hot water distribution, and usually has a molten metal receiving port on one side, depending on the number and position of die casting machines from the middle. It has a branch part. In the hot water distribution gutter 1 shown in FIG. 4, only the tip of this branched portion is shown. A gutter-shaped box 2 is provided so as to be swingable around the tip of the hot water distribution gutter 1 and near the tip of the hot water distribution gutter 1, and the inside is hermetically sealed. 3 is injection sleeve of die casting machine, 3
Reference numeral a is a pouring port, 4 is a plunger tip slidably provided in the injection sleeve 3, and 5 is a plunger.

The gutter-shaped box body 2 is provided so as to be vertically swingable around the swing center portion 6 between, for example, an original position in a horizontal state and an inclined position in which θ = 15 degrees is lifted. Has been. Reference numeral 7 is a cylinder for vertically swinging the gutter-shaped box body 2. 8 is a stopper for adjusting the horizontal position which is the lower limit position, and 9 is a frame. The gutter-shaped box body 2 is inclined so as not to interfere with the maintenance of the injection sleeve 3 and the plunger tip 4 and to return the molten metal from the gutter-shaped box body 2 to the hot water distribution gutter 1. The gutter-shaped box 2
Should be able to move horizontally.

Generally, the gutter-shaped box body 2 constituting the gutter type water heater arranged between the most distal end of the hot water distribution gutter 1 which is a fixed gutter and the injection sleeve 3 is mainly composed of the gutter part 11, It is composed of a gutter lid 12, and an injection sleeve 3 is provided near the tip of the gutter-shaped box body 2.
Metering pouring valve device 1 located directly above the pouring port 3a
3, and an inverted U-shaped pipe device 14 is provided on the hot water distribution gutter 1 side. The gutter part 11 is composed of a tank member 16 that comes into contact with the molten metal 15a, a heat insulating member 17 that keeps it warm, and a box body 18 that stably holds these.

The gutter lid 12 includes a heat retaining member 19 and an exterior member 20.
A heater 21 is attached to the inside of the heat retaining member 19 for retaining or heating the melt 15a in the A chamber, which is the melt passage or the melt reservoir. Besides,
The gutter lid portion 12 has the same drive mechanism 22 as a rotary / linear motion converting mechanism using a ball screw of the metering pouring valve device 13, a servomotor 23, and a reflection type photoelectric tube type molten metal surface sensor 24 for control data. A temperature sensor 25 is attached. Reference numeral 24a is a molten metal level signal generator, and 25a is a molten metal temperature signal generator. On the other hand, the metering pouring valve device 13 includes a servo motor 23, a drive mechanism 22, a ceramic metering valve rod 26, a ceramic valve seat sleeve 27, a heater 28,
It is composed of a guide pipe 29 and the like. Valve seat sleeve 27
Is embedded from the inner surface of the tank member 16 toward the bottom of the heat retaining member 17, and the valve seat sleeve 2 inside the heat retaining member 17 is embedded.
A heater 28 is embedded in the outer periphery of 7. Metering rod 2
The front end of 6 is provided so as to be able to come into contact with or separate from the lower end hole of the valve seat sleeve 27, and can be moved up and down with a rotating operation and can be opened and closed. The servo motor 2
3 receives the pouring instruction, and is controlled by the control device by various information so that accurate measurement is performed.

The inverted U-shaped tube device 14 has an inverted U-shape whose ends are respectively located in the lower part of the A chamber in the gutter-shaped box body 2 and in the lower part of the B chamber, which is the molten metal passage in the hot water distribution gutter 1. It is composed of a tube 30 and a heater 31 of an electromagnetic induction system that heats and heats the tube 30 from the surroundings, is fixed to the gutter portion 11, and moves integrally when the entire gutter box body 2 swings. In the heat retaining member 32 portion of the hot water distribution gutter 1, the space 33 provided around the inverted U-shaped tube 30 is a movement allowance at this time. The inverted U-shaped pipe device 14 allows the molten metal 15b to pass through and move the entire hot water supply device.

A heat insulating material 35 is arranged between the gutter-shaped box body 2 and a part of the hot water distribution gutter. The heat insulating material 35 is preferably elastic, such as ceramic wool. This is because the gap changes due to the swing of the main body. 36 is a gas exhaust passage provided in the heat retaining member 19, 37 is a suction pressurizing device which is also a pressurizing / depressurizing device, 38 is a passage for an inert gas provided in the heat retaining member 19, 38a is an opening / closing valve, 39 is an inert gas It is a supply device.

FIG. 5 shows the metering pouring valve device 13 in detail, so that the tip of the ceramic metering valve rod 26 can come into contact with or separate from the lower end hole of the ceramic valve seat sleeve 27. It is installed so that it can move up and down and open and close. The upper end portion of the metering valve rod 26 is connected to the shaft 41 via a coupling portion 40 having a screw portion, a taper portion, or the like.

The coupling portion 40 is required to have a function of reliably holding the metering valve rod 26 in the high temperature atmosphere without misalignment. The metering valve rod 26 is inserted into the lower end of the holding rod 40a, and is securely held by the tapered portion 40c of the outer sleeve 40b.
An adjusting nut 54 is provided above the holding rod 40a to generate a constant surface pressure on the tapered portion 40c. Therefore, the coupling 55 and the outer sleeve 40b are provided on the upper surface 54a of the nut.
Causes a predetermined force to be applied. On the other hand, the coupling 55
Is keyed to the shaft 41, the rotary reciprocating motion of the shaft 41 can be transmitted to the metering valve rod 26.

Reference numeral 42 denotes a cylindrical body fixedly attached to a bracket 43 attached to the gutter lid portion 12.
A ball screw 44 is provided between the outer peripheral surface of the shaft 42 and the inner peripheral surface of the cylindrical body 42, and the shaft 41 is rotatable and vertically movable. Reference numeral 45 is a toothed belt pulley attached to the upper end of the shaft 41, and 46 is a toothed belt.
It is connected to the servo motor 23 which is a pulse motor shown by. Since the tubular body 42 is a fixed portion, the shaft 41, the belt pulley 45, and the like move up and down by about 15 mm while rotating. In this case, since the belt 46 is flexible,
The belt pulley 45 can be moved up and down to some extent. Therefore, the metering valve rod 26 is structured to rotate even during the valve opening / closing operation. The rotation of the metering valve rod 26 is carried out in order to remove foreign matter adhering to the valve sealing surface 27a and to make the metering valve rod 26 have an automatic centripetal property. The servo motor 23 receives a pouring command and the like,
It is controlled by various information so that accurate measurement can be performed.

Next, the operation in this example will be described step by step. 1. State at the time of starting operation (see FIG. 4) (1) A state in which the molten metal 15b is contained in the chamber B as shown in the figure, but there is no molten metal 15a in the chamber A closed by the metering pouring valve device 13 Then, the inert gas fills the A chamber through the on-off valve 38a and the passage 38. No molten metal has yet entered the inverted U-shaped tube 30. (2) The suction pressurizing device 37 is operated to reduce the pressure in the chamber A to a pressure corresponding to H, and the molten metal 15b is passed through the inside of the inverted U-shaped tube 30 and sucked into the chamber A. (3) Once the flow starts, the suction is stopped, and even if the pressure is released to the atmosphere, the siphon causes the molten metal to flow at a differential pressure of h with respect to the surface of the molten metal 15b. This differential pressure h does not change until the surface of the molten metal 15a rises and reaches the lower surface of the inverted U-shaped tube 30. After reaching, the surface of the molten metal 15a rises due to the differential pressure of Δh and Δh
= 0, that is, when the liquid levels of the molten metal 15a and 15b become the same height, the flow of the molten metal 15a through the inverted U-shaped tube 30 is stopped. (4) At this point, the servo motor control device (not shown) takes in the values of the melt surface sensor 24 and the temperature sensor 25, and waits for a pouring start signal together with other setting data such as the pouring amount.

2. Operation during production operation (normal) (1) In response to a pouring command from the die casting machine main body, the servo motor 23 is activated and the metering valve rod 26 is raised, whereby the valve is opened and the molten metal 15a is injected into the injection sleeve 3 It begins to flow in. (2) After a lapse of a predetermined time, the control device lowers the metering valve rod 26, the valve is closed, and the pouring is completed. When the metering valve rod 26 is lowered, by rotating the metering valve rod 26 about its axis, foreign substances adhering to the sealing surface of the valve seat sleeve 27 can be removed and a centripetal action can be given to the metering valve rod 26. The sealing effect becomes more stable.

(3) In this case, the temperature of the molten metal 15b in the B chamber is set to the minimum temperature T _B required for hot water distribution, and the temperature of the molten metal 15a in the A chamber is set to T _A required for casting, T _A
Carry out the operation in relation to> T _B. Therefore, the temperature of the molten metal 15a is set to a desired temperature by the action of the electromagnetic induction type heater 31 and the heater 21 that can be quickly heated. This is B
If the molten metal 15b in the room is high, a large amount of oxide film is likely to be generated on the surface, and the quality of the molten metal deteriorates due to deterioration. To prevent this, the molten metal should be poured just before pouring into the injection sleeve 3. This is because only 15a has a necessary temperature.

(4) Further, as the heater 31 of the inverted U-shaped tube 30, an electromagnetic induction type heater is used to heat the molten metal inside and to apply the thrust in the flow direction to the molten metal inside to make the molten metal 15b in the B chamber A Move it to the room as quickly as possible. (5) In the metering control, the valve opening degree or the valve opening time of the metering pouring valve device 13 is determined based on one or more data among the molten metal surface position in the chamber A, the molten metal temperature, the molten metal viscosity, and the material characteristics of the molten metal. The amount is increased / decreased so that the amount poured into the injection sleeve 3 and the liquid surface of the molten metal 15a in the chamber A before pouring are the same each time. (6) In this case, the metering valve rod 2 is used as the monitoring value of the valve closed state.
The lower limit position error amount of 6 may be used, or the abnormal current value of the servo motor 23 may be used. (7) When the pouring is completed, an injection command is issued to the die casting machine body to complete one cycle.

[0020]

In the example shown in FIGS. 4 and 5, as described above, the metering pouring valve device 13 includes the drive mechanism 22 and the servo motor which are the rotation / linear motion converting mechanism using the ball screw 44. 23, and a ceramic metering valve rod 26, etc., and is provided so as to be movable up and down and openable and closable. However, this has the following drawbacks. (1) The drive mechanism 22 is fixedly attached to the bracket 43 attached to the gutter lid portion 12, and the ceramic valve seat sleeve 27 that abuts the metering valve rod 26 that is vertically moved and opened / closed by the drive mechanism 22 is the gutter portion. Since it is fixedly embedded in 11, the misalignment occurs between the metering valve rod 26 and the valve seat sleeve 27 due to the difference in the amount of thermal expansion due to the temperature difference between the gutter lid part 12 and the gutter part 11. Since it is guided by the ball screw nut portion 42, misalignment cannot be absorbed, and the molten metal sealability when the valve is closed is poor. (2) Sealing surface 27 of valve seat sleeve 27 and metering valve rod 26
Since a is provided at the lowermost end, heat is not replenished sufficiently for heat dissipation, and solidified matter is generated around the seal surface 27a, and when the valve is closed, solidified matter on the seal surface of the metering valve rod 26 and the valve seat sleeve 27 is closed. The molten metal may not be completely sealed due to the biting of. (3) Sealing surface 27 of valve seat sleeve 27 and metering valve rod 26
Since a is provided at the lowermost end, the tank member 16 and the heat insulating material 1
Foreign matter such as debris of No. 7 is accumulated around the sealing surface 27a, and the sealing surface 27a is apt to be caught when the valve is closed, which may damage the sealing surface 27a or prevent the molten metal from being sealed. (4) Sealing surface 27 of valve seat sleeve 27 and metering valve rod 26
When a valve is closed after the completion of pouring, the sealing surface 27a is in a closed state by biting molten metal and oxides, and the metering valve rod 26 and the valve seat sleeve 2 are closed.
The contact surface of No. 7 was difficult to contact uniformly over the entire circumference, and the sealing property of the molten metal was not perfect. There was a drawback.

[0021]

In order to eliminate these drawbacks, in the present invention, a valve seat portion having a drainage hole is provided as a part of the valve seat sleeve at the lower end of the tip, and the valve seat portion is provided with respect to the valve seat portion. A hot water supply device provided with a metering valve rod that can be freely opened and closed, wherein the molten metal seal part on the upper side of the valve seat part is projected toward the stored molten metal side, and the metering valve rod tip part has a hemispherical shape,
An annular groove is provided in the contact portion of the metering valve rod tip portion with the valve seat portion.

[0022]

When the desired amount of molten metal is completely poured into the injection sleeve, the metering valve rod is lowered to close the valve. The top corner portion of the annular groove having an R-shaped cross section and the tapered valve seat sleeve are in line contact with each other at the tip end of the timepiece valve rod to prevent the molten metal from leaking.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment of the present invention is an improvement of a part of the one shown in FIG. 4. Therefore, the description of the whole is omitted and only the improved part is shown in FIG. 1, FIG. 2 and FIG. Show. Figure 1
As shown in FIG. 2, 26 is a metering valve rod which is opened and closed by a valve rod driving device (not shown) in the trough 11.
Reference numeral 7 is a valve seat sleeve that abuts the metering valve rod 26 to shut off the molten metal, 28 is a heater for heating embedded in the outer periphery of the valve seat sleeve 27, and 29 is a guide pipe that forms a cylindrical partition wall. Box 18 is attached to the lower end of sleeve 27 with bolts or the like.
It is provided at a substantially central portion of the fixed plate 84 attached to the.

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of the apparatus of the present invention, in which a valve seat portion having a drainage port 82 at the lowermost portion of a valve seat sleeve 27 having a U-shaped cross section. 81 is provided, and the upper portion of the valve seat portion 81 is provided with a protruding portion 81b projecting on the side of the molten metal 15a in the shape of a mountain hat, and the metering valve rod is provided at the center of the valve seat portion 81. A hot water outlet 82 having the same axis as 26 is provided.

FIG. 2 is a longitudinal cross-sectional view showing the sealed portion of the molten metal according to the present invention, in which the tip end portion of the metering valve rod 26 is a hemispherical portion 26a and the valve seat sleeve 27 is constituted by the valve. The seal surface 81a of the seat 81 is tapered. Further, an annular groove 26b having a width of, for example, about 1 to 5 mm and a depth of about 1 to 5 mm is engraved in a hemispherical portion 26a at the tip of the metering valve rod 26 that abuts the valve seat portion 81 during the valve closing operation. is there. Further, the corner portion 26c formed when the annular groove 26b is formed in the hemispherical portion 26a has an R shape of, for example, about 1 to 3 mm.

As shown in FIG. 3, a metering pouring valve device 50 provided at the tip of the gutter-shaped box body 2 includes a metering valve rod 26, a valve seat sleeve 27, a guide pipe 29 forming a cylindrical partition wall, and a coupling. 60, a connecting rod 61, a guide device 63, a floating joint 71, and an air cylinder 72.

In this embodiment, in order to pour a predetermined amount of the molten metal 15a into the injection sleeve 3 (opening operation) or to stop the pouring (closing operation), the air for moving the metering valve rod 26 up and down is used. The cylinders 72 are arranged so as to be positioned on the same axis as the metering valve rod 26, and then mounted on a support box 75 having both side surfaces opened. The coupling rod 61 and the metering valve rod 26, which are suspended below the air cylinder 72 via a floating joint 71 mounted on a rod 72a, are coupled by a coupling 60. The connecting rod 61 is guided by a bush 64 incorporated in the guide device 63, but a space between the connecting rod 61 and the bush 64 is large enough to absorb a difference in thermal expansion amount due to a temperature difference between the trough lid portion 12 and the trough portion 11. A gap 65 is provided. The floating joint 71 has an automatic centering mechanism.

When the drive mechanism at the upper end of the metering valve rod 26 is structured as described above, the temperature of the metering valve rod 26 changes significantly and the axial center of the metering valve rod 26 and the valve seat sleeve 27 come into contact with each other. Even if the axis of the seal surface 81a, which is a surface, changes, the axis of the floating joint 71 and the gap 65 provided in the guide device 63 enable the axis to be aligned, and the metering valve rod 26 is It has the effect of operating smoothly.

FIG. 1 shows a state in which the metering valve rod 26 is lowered by the action of the air cylinder 72 after being poured into the injection sleeve 3 for a predetermined time and is brought into contact with the sealing surface 81a of the valve seat portion 81. In the embodiment, the protruding portion 81 provided on the valve seat portion 81
Even if heat is radiated from the lower side of the valve seat portion 81 due to the state of b protruding toward the molten metal 15a side, there is sufficient heat supply from the molten metal 15a. It is difficult for coagulation to be generated and the metering valve rod 26
And the valve seat portion 81 sufficiently abut on the sealing surface 81a, so that the molten metal 15a
It is possible to completely seal.

The pouring work with the above configuration will be described. After pouring a predetermined amount of molten metal 15a into the injection sleeve 3 from the drain port 82 with the metering valve rod 26 being raised, compressed air is introduced into the piston head side of the air cylinder 72 to lower the metering valve rod 26. Then close the valve. When the valve is closed, the valve seat 8
The taper portion 81c provided on the protruding portion 81b and the upper corner portion 26c and the lower corner portion 26c of the R-shaped annular groove 26b provided at the lower portion of the metering valve rod 26 abut and seal. In the embodiment of the present invention, the case where the metered pouring valve device 50 is applied to the hot water supply device has been described, but the present invention is not limited to this and can be applied to other hot water supply devices.

A predetermined amount of molten metal 15a poured into the injection sleeve 3 is filled in a cavity formed between the dies (not shown) by the advance of the plunger tip 4, and is taken out as a product after cooling.

[0032]

As is apparent from the above description, the hot water supply apparatus according to the present invention is provided with the valve seat portion having the hot water outlet as a part of the valve seat sleeve at the lower end of the tip, and the valve seat portion is provided with the valve seat portion. In contrast to the hot water supply device which is provided with a metering valve rod that can be freely opened and closed, the molten metal seal part on the upper side of the valve seat portion is projected toward the stored molten metal side, and the leading end part of the measuring valve rod has a hemispherical shape, Since the annular groove is provided in the contact portion of the metering valve rod tip end portion with the valve seat portion, the heat receiving area on the upper side of the valve seat portion increases, so that even if heat is radiated from the lower side of the valve seat portion, the molten metal Since the amount of heat is replenished to the valve seat side from the retained heat of the valve seat, the generation of solidified substances due to the temperature drop at the valve seat part is prevented and the metering valve rod and valve seat part come into direct contact with each other to seal. Sex is greatly improved. Also, by providing a concave annular groove in the lower part of the metering valve rod, the corner portion of this groove makes line contact with the valve seat sleeve, so that the solidified matter or the like should be caught by the strong edge pressure of the metering valve rod. However, it can be easily removed and completely sealed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of an apparatus of the present invention.

FIG. 2 is a vertical cross-sectional view of a main part showing a sealed portion of the molten metal of the present invention.

FIG. 3 is a vertical sectional view showing an example of a metering pouring valve device.

FIG. 4 is an overall vertical cross-sectional view showing an example of a conventional device.

5 is a vertical cross-sectional view of a main part of the conventional device shown in FIG. 4 according to the present invention.

[Explanation of symbols]

 1 gutter for hot water distribution 2 gutter-shaped box body 3 injection sleeve 8 stopper 13, 50 metering pouring valve device 14 inverted U-shaped pipe device 15a, 15b molten metal 21, 28 heater 22 drive mechanism 23 servo motor 24 molten metal surface sensor 25 temperature sensor 26 metering valve rod 26a hemispherical portion 26b annular groove 26c corner portion 27 valve seat sleeve 27a sealing surface 30 inverted U-shaped tube 31 heater (electromagnetic induction type) 37 suction pressurizing device 39 inert gas supply device 40 coupling portion 44 ball Screws 46 Belts 55, 60 Coupling 61 Connecting rod 71 Floating joint 80 Sleeve part 81 Valve seat part 81a Sealing surface 81b Projecting part 81c Tapered part 82 Hot water outlet 84 Fixing plate

Claims (1)

[Claims] 1. A hot water supply apparatus having a valve seat portion having a hot water outlet as a part of a valve seat sleeve at a lower end of the valve seat, and a metering valve rod openably and closably attached to the valve seat portion. The molten metal seal part on the upper side of the seat part is protruded to the stored molten metal side, the metering valve rod tip part has a hemispherical shape, and an annular groove is formed in the contact part of the metering valve rod tip part with the valve seat part. A hot water supply device characterized by being provided.