JPH0544048Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a water jet, and more particularly to an abrasive supply device for supplying an abrasive into a liquid sprayed from a nozzle of a water jet.

``Prior Art'' Conventionally, water jets have been known in which an abrasive material is mixed into the liquid jetted from a nozzle to increase the cutting ability. This type of water jet includes a nozzle that sprays liquid at high pressure, an abrasive tank that stores an abrasive,
A supply passage is provided which connects the abrasive tank and the nozzle and supplies the abrasive in the abrasive tank into the liquid jetted from the nozzle (Japanese Patent Application Laid-Open No. 1983-1999).
Publication No. 120098).

Known means for feeding the abrasive in the abrasive tank into the liquid include one that feeds the abrasive using a pressurized fluid such as compressed air, and another that generates negative pressure by the liquid passing through the nozzle, and uses that negative pressure to suck the abrasive into the liquid.

``Problems to be solved by the invention'' However, since the abrasive tank is generally located far from the nozzle, there is a time lag between the time the liquid is injected and the abrasive reaches the nozzle. In this case, the abrasive material is not fed until a negative pressure is generated by the jetting of the liquid, which usually results in a time loss of 4 seconds or more.

In addition, when stopping the liquid injection, if the abrasive remains in the supply passage, there is a risk that the abrasive density will become unstable or clogging will occur when restarting the supply. It is necessary to stop ejecting the liquid after the abrasive in the passage is exhausted, and this also causes a loss of time and a loss of the abrasive.

Therefore, particularly in machining where it is necessary to frequently stop the liquid jet, there is a drawback that the loss time accumulates, lengthening the machining time and increasing the amount of abrasive consumed.

``Means for Solving the Problems'' In view of such circumstances, the present invention provides the above-mentioned water jet with a circulation passage connecting the vicinity of the nozzle of the supply passage and the abrasive tank, and a circulation passage closer to the nozzle than the circulation passage. a flow path switching means that is selectively switched to a first switching state in which the supply passage is shut off and the circulation passage is opened; or a second switching state in which the supply passage on the nozzle side is opened and the circulation passage is shut off; 1 switching state, the abrasive supplied from the abrasive tank to the supply passage is circulated to the abrasive tank via the circulation passage.

"Operation" According to the above configuration, when the supply of abrasive to the liquid is stopped, the first switching state of the flow path switching means blocks the supply path closer to the nozzle than the circulation path and opens the circulation path. In addition, the abrasive supplied from the abrasive tank to the supply passage by the feeding means can be circulated to the abrasive tank via the circulation passage.

In this state, when the liquid is injected from the nozzle, if the flow path switching means is immediately set to the second switching state in which the supply path on the nozzle side is opened and the circulation path is shut off, the liquid is circulated from the supply path to the circulation path. The abrasive material that has been stored can be immediately fed into the liquid. And in this state,
Since the circulation passage is blocked, the entire amount of abrasive supplied from the abrasive tank can be supplied to the nozzle, thus allowing precise control of the amount of abrasive to be supplied into the liquid. .

In addition, when stopping the liquid injection again, if the flow path switching means is set to the first switching state just before the injection stops, the abrasive material in the abrasive tank is transferred from the supply path to the circulation path for polishing. The supply of abrasive to the liquid can be immediately stopped while the abrasive material continues to circulate through the material tank.

If the machining is to be completely completed, the abrasive in the supply passage and the circulation passage may be collected into the abrasive tank and then the feeding means may be stopped.

"Example" The present invention will be explained below with reference to the illustrated example.
FIG. 1 shows an embodiment in which the present invention is applied to a water jet that sucks abrasive material into a liquid using negative pressure.

In the figure, a water jet machining head 1 includes a liquid passage 2 through which liquid flows from above to below, and a liquid passage 2 provided at the lower end of the liquid passage 2 to direct the liquid under high pressure toward a workpiece (not shown). It is equipped with a nozzle 3 that injects water. A horizontal abrasive passage 5 is connected in the middle of the liquid passage 2 on the downstream side of an orifice 4 provided in the middle of the liquid passage 2.

The abrasive tank 6 containing the abrasive has a regulating valve 7 at its lower end opening, and the regulating valve 7 and the abrasive passage 5 are connected by an abrasive supply passage 8 . The regulating valve 7 is capable of opening and closing the lower end opening of the abrasive tank 6, and when opened, adjusts the amount of abrasive sent out from the abrasive tank 6 to a predetermined amount, and when closed, controls the supply passage. 8 can be exposed to the atmosphere.

The supply passage 8 is provided with a first on-off valve 1 located near the nozzle 2 for opening and closing the supply passage 8.
1, one end of a circulation passage 12 is connected to an upstream position close to the first on-off valve 11, and the other end of the circulation passage 12 is connected to the upper part of the abrasive tank 6.

In the circulation passage 12, a second on-off valve 13 is provided at a position close to the first on-off valve 11, and an air flow amplifier 14 as an abrasive feeding means is provided at a position near the abrasive tank 6. ing. This air flow amplifier 14 is connected to a compressed air source 15
The compressed air supplied through the on-off valve 16 is ejected toward the abrasive tank 6, and at the same time, the air on the second on-off valve 13 side in the circulation passage 12 is sucked. Such an air flow amplifier 14
is a known product that has been commercially available.

In the above configuration, in order to start machining, the first on-off valve 11 is closed and the second on-off valve 13 is opened (first switching state), the adjustment valve 7 of the abrasive tank 6 is opened, and the on-off valve is opened. 16 is opened to blow out compressed air from the compressed air source 15 from the air flow amplifier 14 toward the abrasive tank 6 .

Then, the air on the second on-off valve 13 side in the circulation passage 12 is sucked by the air flow amplifier 14, so that the inside of the circulation passage 12 and the supply passage 8 become negative pressure, and the pressure is reduced from the regulating valve 7 to the supply passage 8. The abrasive material in the abrasive material tank 6 is adjusted to a predetermined amount and then supplied. This abrasive material is supplied to the supply passage 8
Then, the abrasive material is circulated through the circulation passage 12 into the abrasive tank 6 again.

When this state is reached, liquid is supplied to the liquid passage 2, the liquid is injected from the nozzle 3 toward the workpiece, and immediately the first on-off valve 11 is opened and the second on-off valve 13 is closed (the second on-off valve 13 is closed). 2 switching state). Then, since the abrasive material is immediately supplied into the liquid from the first on-off valve 11 provided near the nozzle 3, the abrasive material is quickly supplied into the liquid after the liquid is supplied to the liquid passage 2 compared to the conventional method. can be supplied.

After closing the second on-off valve 13, the on-off valve 16 may be closed to stop the supply of compressed air to the air flow amplifier 14. In this state, since the second on-off valve 13 is closed, the entire amount of abrasive supplied from the abrasive tank 6 can be supplied to the nozzle 3, and therefore the abrasive to be supplied into the liquid The amount of material can be accurately controlled by the regulating valve 7.

Next, when temporarily stopping the liquid jet,
Prior to stopping the injection, the on-off valve 16 is opened and compressed air is supplied to the air flow amplifier 14.
Then, the second on-off valve 13 is opened and the first on-off valve 13 is opened.
When the on-off valve 11 is closed to return to the first switching state, the abrasive from the abrasive tank 6 is circulated into the abrasive tank 6 via the circulation passage 12 from the supply passage 8 as described above. become.

A first on-off valve 11 provided near the nozzle 3
When the abrasive is closed, the supply of abrasive to the liquid is immediately stopped, so the liquid can be stopped immediately after that, and the liquid can be stopped more quickly than before. wasteful consumption can be reduced.

After this, when restarting machining, the liquid is injected from the nozzle 2 as described above, the first on-off valve 11 and the second on-off valve 13 are set to the second switching state, and the on-off valve 16 is closed. Bye.

On the other hand, in order to completely finish the machining, the above-mentioned liquid injection is temporarily stopped, and then the regulating valve 7 is further closed to stop supplying the abrasive material from the abrasive material tank 6 to the supply passage 8. Stop and supply passage 8
After collecting the abrasive material remaining in the circulation passage 12 into the abrasive tank 6, the on-off valve 16 may be closed.

Figure 2 shows another embodiment of the present invention.
While in the above embodiment the abrasive material is sucked into the liquid using negative pressure, in this embodiment the abrasive material is supplied into the liquid using compressed air.

That is, in this embodiment, compressed air can be supplied from the compressed air source 21 to the supply passage 8 via the on-off valve 22 at a position near the regulating valve 7, and the compressed air source 21 is connected to the abrasive material. It is used as a means of transportation. Therefore, the air flow amplifier 14 and compressed air source 1 in the above embodiment
5 and the on-off valve 16 are omitted.

However, if the supply passage 8 and the circulation passage 12 have long passage lengths, an air flow amplifier 14 or the like may be provided as necessary. The supply passage 8 is prevented from being exposed to the atmosphere.

Furthermore, in this embodiment, whereas the first on-off valve 11 and the second on-off valve 13 constitute a flow path switching means in the above embodiment, in this embodiment, a single three-way flow The passage switching valve 23 constitutes passage switching means.

It is clear that even with such a configuration, substantially the same effects as those of the above embodiment can be obtained.

"Effects of the Invention" As described above, according to the present invention, by switching the flow path of the flow path switching means, the abrasive is circulated through the supply path and the circulation path, and the nozzle is Since it is possible to switch between supplying the abrasive to the liquid through the side supply passage,
Supply and stop of the abrasive to the liquid are performed by a supply passage closer to the nozzle than the circulation passage. Therefore, compared to the conventional case where the entire area of the supply passage is used, the responsiveness of supplying and stopping the abrasive material can be improved, thereby reducing the consumption amount of the abrasive material. You can get the effect that you can.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a circuit diagram showing another embodiment. 2... Fluid passage, 3... Nozzle, 6... Abrasive tank, 7... Regulating valve, 8... Supply passage, 12...
...Circulation passage, 11, 13... Opening/closing valve (flow path switching means), 15, 21... Compressed air source (feeding means), 2
3...Three-way flow path switching valve (flow path switching means).

Claims (1)

[Claim for Utility Model Registration] A nozzle that sprays a liquid at high pressure, an abrasive tank that stores an abrasive, and the abrasive tank and nozzle are connected, and the liquid that is sprayed from the nozzle is contained in the abrasive tank. A water jet is provided with a supply passage for supplying an abrasive material, and a circulation passage connecting the vicinity of the nozzle of the supply passage with the abrasive tank, and a supply passage on the nozzle side of the circulation passage are blocked, and the circulation passage is closed off. a flow path switching means that is selectively switched to a first switching state in which the nozzle side supply passage is opened or a second switching state in which the circulation passage is blocked while opening the supply passage on the nozzle side; 1. An abrasive supply device for a water jet, comprising a feeding means for circulating abrasive supplied to a supply passage to an abrasive tank via a circulation passage.