CN114619015A

CN114619015A - Fixed vacuum valve

Info

Publication number: CN114619015A
Application number: CN202011442205.7A
Authority: CN
Inventors: 唐乃光; 陆致玮; 黄菀筠; 赖建利
Original assignee: Metal Industries Research and Development Centre
Current assignee: Metal Industries Research and Development Centre
Priority date: 2020-12-11
Filing date: 2020-12-11
Publication date: 2022-06-14

Abstract

A fixed vacuum valve includes a movable-side exhaust block and a fixed-side exhaust block. The movable side exhaust block comprises a base body and a guide body which extends in a conical shape towards the direction far away from the base body, and the movable side exhaust block is provided with an exhaust channel which extends from the conical end of the guide body to the base body. The fixed side exhaust block and the guide body together enclose a flow channel, the flow channel spirally extends to the conical end of the guide body from one end of the guide body, which is connected with the base body, and the flow channel is communicated with the exhaust channel. The flow channel can reduce occupied space through a spiral structure, and has longer path distance under the same arrangement space, thereby ensuring that molten metal can be cooled and solidified in the flow channel and cannot enter a vacuum pipeline or be sucked into a vacuum barrel.

Description

Fixed vacuum valve

Technical Field

The invention relates to a device for vacuum die casting, in particular to a fixed vacuum valve for vacuum die casting.

Background

Die casting is a metal casting process that injects a molten metal liquid into a mold cavity by high pressure and maintains the pressure until the metal solidifies. Since the molten metal is injected under high pressure, the molten metal is easy to draw in outside air in the process of entering the die cavity, so that the finished casting product has air holes to cause defects. In order to improve this point, a vacuum die casting technology for reducing the amount of air trapped in the die cavity by pumping air out of the die cavity is available, however, in this technology, a vacuum valve is required to be disposed on the die casting mold, and a vacuum barrel, a vacuum pump, a vacuum pipeline, a controller, a signal line and other components are additionally connected, the vacuum barrel is pumped into a vacuum environment by the vacuum pump, and after the vacuum valve is opened, the negative pressure of the vacuum barrel can suck out the air in the die cavity through the vacuum valve.

Since the molten metal is sucked out by the negative pressure after the air is sucked out, the vacuum valve must be closed in time to prevent the molten metal from flowing into the vacuum pipeline to cause damage to the equipment, so the vacuum valve is said to be an important component in vacuum die casting. The vacuum valve is divided into a passive type, an active type and a fixed type according to the closing time and the action mode. As for the passive vacuum valve, refer to the vacuum ダイカスト device in JP4644645B2, which is a complex linkage mechanism, once the molten metal enters the vacuum valve, the switch is pushed to close the vacuum valve, so as to prevent the molten metal from entering the vacuum pipeline. Although the passive vacuum valve is simple to control, the cost is high due to the complex mechanism.

FOR the active vacuum valve, US patent No. US9050653B2, "successful vacuum DEVICE FOR DISCHARGING GAS FROM a MOULD" is referred, and the active vacuum valve is actively controlled by an operator to close, and the operator needs to calculate the filling time or stroke setting and send a signal to close the vacuum valve. The vacuum valve has a simple structure and greatly reduces the cost, but because the closing time is artificially controlled, personnel often close the vacuum valve at a conservative time point to avoid the metal liquid from entering a vacuum pipeline, so that more gas is remained in a mold cavity to cause casting defects.

The fixed vacuum valve has no movable mechanism, i.e. it can not actively or passively close the valve body, and has a runner with smaller cross-section, after the air passes through the runner, the molten metal can then enter the runner, and gradually condenses and solidifies in the runner, so that the runner is blocked to prevent the molten metal from continuously flowing in, thus the gas can be pumped out of the die cavity, and the molten metal can not flow into the vacuum pipeline. In order to make the molten metal be solidified in the flow channel, the flow channel needs to have a longer stroke or more heat dissipation fittings beside the flow channel besides having a smaller cross-sectional area, both of which greatly increase the volume of the vacuum valve.

Disclosure of Invention

The invention aims to provide a fixed vacuum valve which occupies a small volume and can effectively condense molten metal.

The invention provides a fixed vacuum valve, which comprises a movable side exhaust block and a fixed side exhaust block, wherein the movable side exhaust block comprises a base body and a guide body which is arranged on one end part of the base body and extends in a cone shape from the end part to the direction far away from the base body, the movable side exhaust block is provided with an exhaust channel which extends from the cone end of the guide body to the other end of the base body, the exhaust channel is used for gas circulation and is exhausted outside, the movable side exhaust block and the fixed side exhaust block together enclose a flow channel and an interface, the flow channel extends from one end, connected with the base body, of the guide body in a spiral shape to the cone end of the guide body, the flow channel is communicated with the exhaust channel, and the interface is communicated with the flow channel and the outside.

Preferably, the stationary vacuum valve wherein the taper of the guide body of the movable side exhaust block is 5 ° to 30 °.

Preferably, the fixed-side exhaust block includes a receiving portion for inserting the guiding body of the movable-side exhaust block, and an outer fixing portion sleeved on the receiving portion, the receiving portion and the outer fixing portion cooperate to define a cooling water channel extending spirally and located outside the flow channel, and the outer fixing portion defines a water inlet and a water outlet communicating with the cooling water channel.

Preferably, the fixed vacuum valve further comprises a guide body of the movable exhaust block, wherein the guide body of the movable exhaust block forms a continuous spiral groove on an outer surface, and the groove and an inner surface of the receiving portion of the fixed exhaust block cooperate to define the flow passage.

Preferably, the fixed vacuum valve, wherein the draft angle of the groove is 1 ° to 3 °.

Preferably, in the fixed vacuum valve, the receiving portion of the fixed side exhaust block forms a continuous spirally extending through groove on an outer surface, and the through groove cooperates with an inner surface of the outer fixing portion to define the cooling water channel.

Preferably, the fixed vacuum valve further comprises a filter screen detachably disposed in the exhaust passage, and the base further defines an air inlet communicating with the exhaust passage.

Preferably, the number of the circulating turns of the flow channel is at least 3 or more.

The invention has the beneficial effects that: after the air flows along the flow channel and is pumped out from the air outlet through the flow guide port and the exhaust channel, the molten metal entering from the interface flows along the spiral flow channel and is cooled and solidified in the flow channel to block the flow channel, so that the molten metal cannot flow into a vacuum pipeline through the air outlet. Compared with the plane path design of a common vacuum valve, the flow channel can reduce the occupied space through the spiral structure, and has longer path distance under the same arrangement space, so that the molten metal can be cooled and solidified in the flow channel and cannot enter a vacuum pipeline or be sucked into a vacuum barrel.

Drawings

FIG. 1 is an exploded perspective view illustrating a fixed vacuum valve embodiment of the present invention;

FIG. 2 is a side sectional view illustrating a sectional aspect of the present embodiment; and

fig. 3 is a perspective view illustrating an outer fixing portion in the present embodiment.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

Referring to fig. 1, 2, and 3, the embodiment of the fixed vacuum valve of the present invention includes a movable side exhaust block 1, a fixed side exhaust block 2 enclosing and defining an inner space 211 for the movable side exhaust block 1 to be detachably inserted, and a filter screen 3 detachably disposed in the exhaust passage 11. The movable-side exhaust block 1 includes a base 12, and a guide 13 disposed at an end of the base 12 and extending from the end in a tapered shape in a direction away from the base 12. The movable-side exhaust block 1 has an exhaust passage 11 extending from the tapered end of the guide body 13 to the other end of the base body 12. The section of the exhaust channel 11 located in the base body 12 has a larger pore size than the section located in the guide body 13. The base body 12 defines, at an end remote from the guiding body 13, an air outlet 121 communicating with the exhaust channel 11, and an air inlet 122 spaced apart from the air outlet 121 and communicating with the exhaust channel 11. The guiding body 13 is formed with a continuous helically wound groove 131 on the outer surface, the groove 131 being wound at least 3 turns or more, preferably 3.5 turns, over a distance of about 10 times greater than a conventional path extending straight (corresponding to an axial direction of the guiding body 13). The draft angle formed by the groove 131 is 1 ° to 3 °, and the taper of the guide body 13 is 5 ° to 30 °. In the present embodiment, the base 12 is cylindrical, and the guiding body 13 is truncated cone-shaped (also called truncated cone-shaped), but the invention is not limited thereto.

The fixed side exhaust block 2 includes a receiving portion 21 having an inner surface surrounding and defining the inner space 211 and being shaped like a frustum, and an outer fixing portion 22 sleeved on the receiving portion 21. The internal space 211 is partitioned by the movable-side exhaust block 1 into a continuous spirally extending flow passage 212, a flow guide port 213 communicating the flow passage 212 with the exhaust passage 11, and a connection port 214 communicating the flow passage 212 with the outside. The flow channel 212 is obtained by matching the groove 131 of the guiding body 13 and the inner surface of the receiving portion 21, and extends from one end of the guiding body 13 connected with the base 12 to the conical end of the guiding body 13 in a spiral manner. The diversion port 213 is located between the guide body 13 and the receiving portion 21 in the axial direction. The interface 214 is defined by the base 12 and the receiving portion 21, and extends outward along the radial direction of the base 12. The receiving portion 21 forms a continuous spiral-wound through groove 215 on the outer surface, and the through groove 215 cooperates with the inner surface of the outer fixing portion 22 to define a cooling water channel 216 extending spirally and located outside the flow channel 212. The outer fixing portion 22 defines a water inlet 221 and a water outlet 222 communicating with the cooling water channel 216 and extending along a radial direction of the outer fixing portion 22.

The application process of this embodiment is as follows: the movable-side exhaust block 1 and the fixed-side exhaust block 2 are fixed to the movable side and the fixed side of the die casting mold by bolts or the like, respectively, and when the die casting mold is closed, the movable-side exhaust block 1 is also engaged with the fixed-side exhaust block 2. The port 214 is communicated with a die cavity of a die-casting die, connected with the air outlet 121 through a vacuum pipeline, and is used for inputting cooling water (after flowing in the cooling water channel 216, the cooling water is output from the water outlet 222) through the water inlet 221. When the air extraction is started, the air in the mold cavity sequentially passes through the interface 214, the flow channel 212, the flow guide opening 213, and the exhaust channel 11, and then is output to the vacuum pipeline (sent to the vacuum barrel) from the air outlet 121, and since the air inlet 122 is connected to the air supply device through a pipeline (not opened at this time), the air tends to flow out from the air outlet 121 rather than the air inlet 122. When the air in the mold cavity is exhausted, the molten metal is sucked by the negative pressure and enters the flow channel 212 from the interface 214, and when the distance of the flow channel 212 is long and the cooling water channel 216 is cooled, the molten metal is cooled and solidified in the flow channel 212 and is blocked in the flow channel 212 to stop advancing, so that the effect of preventing the molten metal from entering the vacuum pipeline is achieved.

After the die casting mold is opened, the movable side exhaust block 1 is also separated from the fixed side exhaust block 2 (the guide body 13 has a taper of 5 ° to 30 ° to facilitate the demolding of the movable side exhaust block 1), and because the groove 131 has a proper draft angle (i.e. the aforesaid draft angle of 1 ° to 3 °), the metal solidified in the runner 212 is ejected together with the casting to be demolded, thereby completing the vacuum die casting process. If solidified metal powder or parting agent is driven by air in the vacuum die-casting process to enter the exhaust channel 11, the filter screen 3 can block the powder or the parting agent to prevent the powder or the parting agent from invading a vacuum pipeline, and after the vacuum die-casting is finished, the air feeding device can blow the filter screen 3 through the air inlet 122 to blow off the powder on the filter screen 3.

In summary, in the same space, the flow channel 212 of the present invention can have a longer path by being coiled, and in cooperation with the cooling of the cooling water channel 216, the cooling and solidification of the molten metal in the flow channel 212 can be ensured, and the inclination angle of the groove 131 is favorable for the demolding of the solidified metal, and in addition, the filter screen 3 can block metal powder or parting agent, and the filter screen 3 can be cleaned by blowing through the air inlet 122, so as to further keep the vacuum pipeline smooth and convenient for cleaning, and thus the object of the present invention can be achieved.

Claims

1. A fixed vacuum valve, characterized in that: fixed vacuum valve contains movable side exhaust piece and fixed side exhaust piece, movable side exhaust piece includes the base member, and set up in on an end of base member and certainly the tip is towards keeping away from the direction extension of base member is the guide body of taper, movable side exhaust piece have by the awl end of guide body extends to the exhaust passage of the base member other end, exhaust passage is used for supplying the gas circulation and discharges out the external world, movable side exhaust piece with fixed side exhaust piece encloses jointly and encloses and goes out runner and interface, the runner certainly the guide body links up the one end of base member is the spiral and extends to the awl end of guide body, the runner intercommunication exhaust passage, the interface intercommunication runner and external world.

2. The fixed vacuum valve of claim 1, wherein: the taper of the guide body of the movable side exhaust block is 5-30 degrees.

3. The fixed vacuum valve of claim 1, wherein: the fixed side exhaust block comprises a bearing part for inserting the guide body of the movable side exhaust block and an outer fixing part sleeved on the bearing part, the bearing part and the outer fixing part are matched to define a cooling water channel which extends spirally and is positioned on the outer side of the flow channel, and the outer fixing part defines a water inlet and a water outlet which are communicated with the cooling water channel.

4. The fixed vacuum valve of claim 3, wherein: the guide body of the movable side exhaust block forms a continuous spiral extending groove on the outer surface, and the groove and the inner surface of the bearing part of the fixed side exhaust block are matched to define the flow channel.

5. The fixed vacuum valve of claim 4, wherein: the draft angle of the groove is 1-3 degrees.

6. The fixed vacuum valve of claim 3, wherein: the bearing part of the fixed side exhaust block forms a continuous spirally extending through groove on the outer surface, and the through groove is matched with the inner surface of the outer fixed part to define the cooling water channel.

7. The fixed vacuum valve of claim 1, wherein: the fixed vacuum valve further comprises a filter screen detachably arranged in the exhaust passage, and the base body further defines an air inlet communicated with the exhaust passage.

8. The fixed vacuum valve of claim 1, wherein: the number of the surrounding circles of the flow channel is at least more than 3 circles.