JPH0239646Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is applied to, for example, a die casting machine, in which vacuum piping is connected to a gas venting device that removes gas remaining in the cavity of a mold during injection of molten metal, and powder particles. It relates to piping structures such as piping for conveying gas slightly mixed with bodies and sticky substances.

[Conventional technology]

Die casting is a widely used casting method for manufacturing precision products in large quantities. However, by filling the cavity with molten metal at high speed and high pressure, the gas in the cavity does not escape sufficiently and mixes with the molten metal, resulting in the product being mixed with the molten metal. Therefore, in some cases, it is not suitable for products where the integrity of the product is important, with no nests inside the product. Conventionally, for example, as disclosed in Japanese Patent Publication No. 58-46386, the gas inside the cavity is discharged through the exhaust passage by opening the exhaust passage leading from the cavity to the outside by the action of a valve, and then injecting the gas. A gas venting device is provided, which is configured to block the outflow of the molten metal by applying the inertial force of the large mass of the molten metal that has advanced from inside the cavity to the valve and closing it when the molten metal has almost finished being discharged. gas is being vented. Further, as shown in Japanese Patent Publication No. 41-10612, for example, a degassing device has been proposed in which the forward position of the plunger of the injection cylinder is activated to close a solenoid valve to block the outflow of molten metal.

In order to further ensure degassing, this type of degassing device is sometimes attached with a vacuum device that forcibly discharges the gas using a vacuum pump. However, in this case, if the valve is not completely closed, the molten metal that has progressed through the discharge path may flow into the vacuum piping toward the vacuum pump and solidify within the connection of the vacuum piping. If left unattended, air circulation will be obstructed and the suction ability will deteriorate, so it is necessary to remove this solidified material. That is, FIG. 4 is a vertical cross-sectional view of a conventional piping connection part that is a part of the piping structure of a vacuum device attached to this type of degassing device. Fitting 2 is attached to the threaded part 1a of
is screwed into the threaded part 2a of the joint 2,
A hose 3 is press-fitted and fixed with a hose band 4. 5 indicates the solidified molten metal. When removing the solidified material 5, the joint 2 is rotated to loosen the threaded portion with the threaded portion 1a and removed.

[Problem that the invention attempts to solve]

However, in such a conventional vacuum piping structure, the joint 2 must be loosened in order to remove the molten metal solidified material 5 at the pipe connection part as described above, and in this case, the solidified material 5 is attached to the threaded part of the joint 2. Since the solidified material 5 is solidified within the threads of the thread, a large force is required to rotate the fitting 2, and it is necessary to remove the solidified material 5 that has solidified within the thread after separating the fitting 2 from the pipe 1. , the screw threads had to be removed manually to avoid damage, which required a long time and great effort. Also, the inner hole 2 of the joint 2
There was also the problem that removal of the solidified material 5 solidified in the inner hole 2b was troublesome and took a long time because the inner hole 2b had a small diameter and a rough surface.

[Means for solving problems]

In order to solve these problems, in the present invention, for example, a threaded portion is provided on the outer peripheral surface of the piping on the side of the gas venting device, etc., and a flange is attached to the end of this piping so as to be movable in the axial direction. and a flange provided on the joint pipe are removably connected to each other, and a taper is provided between the connection ends of the inner hole of the pipe and the inner hole of the joint pipe so that the joint pipe side has a smaller diameter.

[Effect]

With this configuration, when removing the solidified molten metal that has flowed into the joint between the pipe and the joint pipe, the flange connection between the pipe and the joint pipe is released, and then the flanges are screwed together. If it is opened in the axial direction by operation, etc., the solidified material will peel off from the inner peripheral surface of the joint pipe due to the action of the tapered surface, so if the joint pipe is removed, the solidified material remaining on the inner peripheral surface of the pipe can be removed.

〔Example〕

Figures 1 and 2 show an example in which the piping structure according to the present invention is implemented in a gas venting device of a die-casting machine. FIG. 2 is a schematic configuration diagram between a vacuum pump and a vacuum pump. In the figure, a cavity 12 is formed in the clamped fixed mold 10 and movable mold 11, and the mold is fed into the injection sleeve 13 on the fixed mold 10 side and pushed by the plunger 14 of the injection flange. The molten metal 15 is injected into the cavity 12 and filled. A discharge passage 16 leading from the cavity 12 to the outside is opened when the molten metal 15 is injected to allow the gas in the cavity 12 to pass through and discharge the molten metal 1.
A gas venting device 17 is connected, which is equipped with a valve that is closed by the pressure of the molten metal 15 when the filling of the molten metal 5 is completed. on the other hand,
A vacuum pump 19 directly connected to the motor 18 is provided on the base side of the die-casting machine, and a vacuum tank 20 is connected to this.
is connected. And between this piping 22 and the piping 23 connected to the degassing device 17,
They are connected by a hose 25 having a continuous portion 24 at both ends.

Of these, the connecting portion 24 between the gas venting device 17 side piping 23 and the hose 25 will be explained based on FIG. 1. The pipe 23 is not provided with a threaded portion on the inner circumferential surface, which was conventionally provided, but has a threaded portion 23 on its outer circumferential surface.
a and a small diameter portion 23b without a thread. 26 is a threaded portion 26a that is threadedly engaged with the threaded portion 23a.
and a threadless small diameter portion 26 that fits into the small diameter portion 23b.
b is provided on the inner peripheral surface, and after screwing, it is fixed to the piping 23 side with bolts 27, and the large diameter flange portion 26c has bolt holes 2
6d and screw holes 26e are provided alternately at positions dividing the circumferential direction into a plurality of equal parts. 28 is the small diameter part 2
This is a sealing member interposed between 3b and 26b.
On the other hand, the hose 25 has a large diameter flange portion 29.
a and a small diameter threaded portion 29b.
A threaded portion 29b is inserted and fixed, and both large diameter flange portions 26c, 29a are inserted into each bolt hole 2.
They are fixedly connected by a plurality of bolts 30 inserted at 6d. 31 is a sealing member interposed between both large diameter flange portions 26c and 29a. The screwing end limit of the pipe 23 is regulated by bringing the open end 23c into contact with the stepped portion 26f of the flange 26, and the open end 23c and the opening of the inner hole 29c of the joint pipe 29 provided with a gentle taper. By forming the inner hole 29c with a smaller diameter than the inner hole 23d, there is a hole 2 between the end 29d and the inner hole 29c, which has a smaller diameter on the joint pipe 29 side.
Step tapers 26g and 29e are formed.

With the above configuration, the molten metal 15 is supplied to the injection sleeve 13 and the plunger 1
4 is advanced, molten metal 15 is injected and filled into the cavity 12. At this time, the pressure inside the vacuum tank 20 is reduced by the vacuum pump 19, and the air inside the gas venting device 17 is sucked through the piping 23, hose 25, and piping 22, so the gas inside the cavity 12 is exhausted. It is discharged out of the device from the outlet via the valve opening the passage 16. After filling the cavity 12 with the molten metal 15, this molten metal 15
However, the valve is closed by the pressure of the molten metal 15, which has a larger mass than the gas, so the molten metal 1
Passage of 5 is blocked.

In this case, as described above, the molten metal 15 is
may flow into the interior and solidify within the connecting portion 24.
Since it is necessary to remove this, the removal operation will be explained based on the operation explanatory diagrams shown in FIGS. 3a to 3c. In FIG. 3a, the molten metal solidified material 32 is
It solidifies and adheres from the inner hole 23d of No. 3 to the inner hole 29c of the joint pipe 29. Therefore, after loosening and removing the bolts 30, when the bolts 33 are screwed into the plurality of bolt holes 26e and rotated alternately as shown in FIG.
By pushing the end face of the joint pipe 29, the joint pipe 29 is separated from the pipe 23, and the solidified material 32 is moved to the joint 29.
It is peeled off from the inner hole 29c. In this case, due to the provision of the taper 29e and the screw action of the bolt 33, it can be easily peeled off. Next, when the bolts 27 are loosened and the flange 26 is rotated as shown in FIG. Ru. In this case, the provision of the taper 26g facilitates peeling. By doing this, the solidified material 32 is attached only to the inner hole 23d of the pipe 23, and since this attachment part does not have a threaded part like the conventional one shown in FIG. The solidified material 32 can be removed easily and reliably because the solidified material 32 is not firmly fixed and there is no need to be careful not to damage the threaded part, making it possible to perform somewhat rough work. If removal is difficult, it can be removed using a tool such as a lathe tool.

Note that in this embodiment, the flange 26 has a taper 26.
Although the example in which the inner hole 23d is provided has been shown, a straight hole having the same diameter as the inner hole 23d may be used. Furthermore, in this example,
An example is shown in which the taper is formed in two stages, 26g and 29e, but the end face 23c
It is also possible to form a linear taper from the end face 29d to the end face 29d. Furthermore, the connecting portion 24 on the piping 22 side is connected to the piping 23
It may have the same configuration as the connecting portion 24 on the side, or it may have another configuration since there is little risk that the molten metal 15 will reach this point. Further, although the flange 26 is attached to the end of the pipe 23 by the threaded portion 23a, if the flange 26 is attached so that it can move in the axial direction, it can be simply slid without using the screw 23a. Get a flange 26 with a plurality of bolts 2
It is also possible to securely attach it to the end of the piping 23 using 7 or the like.

[Effect of idea]

As is clear from the above explanation, according to the present invention, in a piping structure such as a vacuum piping of a degassing device in a die-casting machine, a flange is moved in the axial direction at the end of the outer peripheral surface of the piping such as the piping on the degassing device side. The flange can be attached freely, and this flange and the flange provided on the joint pipe can be detachably connected.
If a taper is provided between the connecting end of the inner hole of the pipe and the inner hole of the joint pipe so that the diameter of the joint pipe is smaller, molten metal, etc. flows into the joint between the pipe and the joint pipe and sticks to the inner hole. In this case, after uncoupling the two flanges and separating them by screw action, etc., the flange attached to the end of the pipe is moved in the direction of removal, and the molten metal solidification is removed by the action of the taper. etc. can be easily peeled off from the inner hole of the joint pipe and piping, so all that is required is to peel off the solidified matter adhering to the unthreaded inner hole on the piping side, and the removal of solidified matter is much easier than before. This makes it easy to reduce labor and improve productivity, and it does not damage the connecting parts.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the piping structure according to the present invention, with Figure 1 being a vertical cross-sectional view, and Figure 2 being an overview of the structure between the mold and vacuum pump of a die-casting machine in which this was implemented. 3 a to 3 c are vertical cross-sectional views of the piping structure shown to explain the removal operation of molten metal solidified material, etc., and FIG. 4 is a vertical cross-sectional view of the conventional vacuum piping structure shown corresponding to FIG. 1. It is a diagram. 17...Gas venting device, 19...Vacuum pump,
22, 23...Piping, 23a...Threaded part, 23c
...Opening end, 23d...Inner hole, 24...Connection part,
25...Hose, 26...Flange, 26a...
Threaded part, 26c...Large diameter flange, 26e...Bolt hole, 26g...Taper, 29...Joint pipe, 2
9a...Large diameter flange, 29c...Inner hole, 29d
...open end, 29e...taper, 33...bolt.

Claims (1)

[Scope of utility model registration request] A flange is attached to the outer peripheral end of one of the pipes so as to be movable in the axial direction, and this flange and a flange provided on the joint pipe are removably connected, and the inner hole of the pipe and the inner hole of the joint pipe are connected. A piping structure characterized by having a taper between the ends so that the joint pipe side has a smaller diameter.