Abrasive material supply device for use in abrasive water jet machining equipment

Abstract

To provide a polishing material supply device to be used for an abrasive water jet processing device capable of continuously supplying a polishing material.SOLUTION: A polishing material supply device to be used for an abrasive water jet processing device includes: a first tank 2 that stores a polishing material A; a second tank 3 that is arranged below the first tank 2 and stores the polishing material A supplied from the first tank 2; a polishing material passage 6b that moves the polishing material A from the first tank 2 to the second tank 3; and an opening / closing mechanism 6 that switches opening / closing of the polishing material passage 6b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an abrasive supply device for use in an abrasive water jet machining device. [Background technology]

[0002] Conventionally, abrasive supply devices used in abrasive water jet machining generally use an air compressor to pump the abrasive from an abrasive supply tank containing the abrasive. In such abrasive supply devices, the abrasive is sent through piping from the abrasive supply tank to the abrasive nozzle.

[0003] Japanese Patent No. 2931238 (hereinafter referred to as Patent Document 1) discloses an abrasive recovery device having a mechanism for classifying, recovering, and replenishing abrasives (polishing materials). In this abrasive recovery device, the abrasives are pressure-fed and circulated in hoppers that store the abrasives, such as a new material hopper, a recovery hopper, and a pressure-fed hopper.

[0004] Japanese Patent Publication No. 4881179 (hereinafter referred to as Patent Document 2) discloses that in order to stably supply abrasive material into an abrasive nozzle, the abrasive material is pumped from an abrasive material supply tank and stored in a measuring hopper, and then the abrasive material is pushed out using a needle valve. Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, a stop valve located below the collection hopper and an open valve located above the pressure hopper are opened to supply abrasive from the collection hopper to the pressure hopper. However, the collection hopper and the pressure hopper are separate components and are not connected, and there is a distance between the collection hopper and the pressure hopper. As a result, when the abrasive is supplied, some of the abrasive may scatter around. Therefore, there is a need for a more efficient movement of the abrasive between the collection hopper and the pressure hopper.

[0006] Patent Document 2 does not disclose the opening and closing valve of the abrasive supply tank or the detailed structure thereof.

[0007] Furthermore, it is required not only to stably supply the abrasive from the abrasive supply tank but also to use a large volume of abrasive to continuously supply the abrasive.

[0008] In addition, in order to improve work efficiency, it is necessary to develop a device that can automatically switch on and off the abrasive supply (pressure feeding) process.

[0009] An object of the present invention is to provide an abrasive supply device for use in an abrasive water jet machining device that is capable of continuously supplying abrasives. [Means for solving the problem]

[0010] A first aspect of the present invention is a first tank containing an abrasive; a second tank disposed below the first tank and configured to accommodate the abrasive supplied from the first tank; an abrasive passageway for moving the abrasive from the first tank to the second tank; an opening / closing mechanism for switching the opening and closing of the abrasive passage; The abrasive supply device is used in an abrasive water jet machining device.

[0011] In addition, a second aspect of the present invention is the abrasive supply device; a high-pressure pump for generating high-pressure water; an abrasive nozzle that sprays the abrasive supplied from the abrasive supply device together with high-pressure water supplied from the high-pressure pump; The abrasive water jet machining device has: [Effects of the Invention]

[0012] According to the abrasive supply device used in the abrasive water jet machining device of the present invention, abrasives can be continuously supplied. [Brief explanation of the drawings]

[0013] [Figure 1] Schematic diagram of an abrasive supply device according to an embodiment [Figure 2] FIG. 10 is a cross-sectional view showing details of the opening and closing mechanism of the embodiment. [Figure 3] 1 is a cross-sectional view showing a state in which an abrasive is supplied in an abrasive supplying device according to an embodiment; [Figure 4] FIG. 1 is a cross-sectional view showing a state in which the supply of abrasive is stopped by a first opening / closing unit in the abrasive supplying device according to the embodiment; [Figure 5] FIG. 10 is a cross-sectional view showing a state in which the supply of abrasive is stopped by a second opening / closing unit in the abrasive supplying device according to the embodiment. [Figure 6] FIG. 1 is a cross-sectional view showing a state in which the supply of abrasive is stopped by the first and second opening / closing portions in the abrasive supplying device according to the embodiment; [Figure 7] Cross-sectional view of abrasive supply device according to Modification 1 [Figure 8] Cross-sectional view of an abrasive supply device according to a second modification [Figure 9] Schematic diagram of an abrasive water jet machining device using an embodiment BEST MODE FOR CARRYING OUT THE INVENTION

[0014] Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0015] As shown in FIG. 9, the abrasive supplying device 1 of this embodiment supplies an abrasive A to an abrasive nozzle 101 of an abrasive water jet processing device 100. For example, by spraying the abrasive water jet at a metal member or the like while mixing the abrasive A into the water jet, the metal member or the like can be cut or peeled off. The abrasive A may be made of any material, such as garnet, alumina, or silicon carbide, and may be commercially available. The particle shape and diameter of the abrasive A are not particularly limited.

[0016] As shown in FIG. 1, the abrasive supplying device 1 includes a first tank 2, a second tank 3, a support part 4, a lid 5, and an opening / closing mechanism 6.

[0017] The first tank 2 contains an abrasive A. The abrasive A is placed in the first tank 2 either manually by an operator or automatically using a conveying device (not shown). The lid 5 is placed on top of the first tank 2. For example, the abrasive A is placed inside the first tank 2 with the lid 5 removed, thereby filling the first tank 2 with the abrasive A. If there is a possibility that impurities (contamination or foreign matter) or abrasive particles of a different size than specified are mixed in the abrasive A, a filter may be placed in the first tank 2. This makes it possible to make the particle size of the abrasive A uniform.

[0018] 3 to 6, a first tank abrasive amount reference line (upper limit) C1 and a first tank abrasive amount reference line (lower limit) C2 are defined inside the first tank 2 and can be visually or electromagnetically confirmed. For example, by disposing a first tank upper limit sensor S1 and a first tank lower limit sensor S2 at the positions of the first tank abrasive amount reference line (upper limit) C1 and the first tank abrasive amount reference line (lower limit) C2, respectively, the amount of abrasive A can be electromagnetically confirmed next to the first tank 2 or remotely.

[0019] The second tank 3 is disposed below the first tank 2. The second tank 3 stores the abrasive A supplied from the first tank 2. The second tank 3 is a tank for supplying the abrasive A to the abrasive nozzle 101. If there is a possibility that impurities (contamination or foreign matter) or abrasive particles of a different size than specified are mixed in the abrasive A, a filter may be placed in the second tank 3. This makes it possible to make the particle size of the abrasive A uniform.

[0020] 3 to 6, the amount of abrasive A can be visually or electromagnetically confirmed by defining a second tank abrasive amount reference line (upper limit) C3 and a second tank abrasive amount reference line (lower limit) C4 inside the second tank 3. For example, by arranging a second tank upper limit sensor S3 and a second tank lower limit sensor S4 at the positions of the second tank abrasive amount reference line (upper limit) C3 and the second tank abrasive amount reference line (lower limit) C4, respectively, the amount of abrasive A can be electromagnetically confirmed next to the second tank 3 or remotely.

[0021] The support unit 4 supports the first tank 2 and the second tank 3. As shown in Fig. 1, the support unit 4 is composed of four support posts. Note that the number of support posts for the support unit 4 can be selected appropriately, such as three or five, depending on the weight and arrangement of the first tank 2, the second tank 3, and peripheral devices.

[0022] The lid 5 covers the top of the first tank 2 to prevent the abrasive A contained in the first tank 2 from scattering around. The example shown in FIG. 1 shows a lid 5 with a handle. For a large-capacity first tank 2 that holds a large amount of abrasive A, the lid 5 may be automated. For example, the lid 5 may be connected to a part of the first tank 2, and the lid 5 may be opened and closed manually or electromagnetically.

[0023] The opening / closing mechanism 6 switches between opening and closing the abrasive passage 6b between the first tank 2 and the second tank 3. As shown in FIGS. 1 to 6, the opening / closing mechanism 6 has an opening / closing mechanism main body 6a, the abrasive passage 6b, an air passage 6c, an inlet 6d, a discharge port 6e, a first opening / closing unit 7, and a second opening / closing unit 8. The first opening / closing unit 7 and the second opening / closing unit 8 may be operated separately, or the first opening / closing unit 7 and the second opening / closing unit 8 may be operated simultaneously.

[0024] The opening / closing mechanism body 6a is disposed below the first tank 2. The opening / closing mechanism body 6a is fixed between the first tank 2 and the second tank 3. Inside the opening / closing mechanism body 6a, the abrasive A moves efficiently from the first tank 2 to the second tank 3.

[0025] The abrasive passage 6b is formed inside the opening / closing mechanism main body 6a. To allow the abrasive A to fall from the first tank 2 to the second tank 3 in the direction of gravity, the abrasive passage 6b penetrates from the bottom of the first tank 2 to the top of the second tank 3. The abrasive passage 6b may be, for example, cylindrical or polygonal in shape, but is not limited thereto. Because the abrasive A is a hard material, a cover or coating may be placed on the surface of the abrasive passage 6b to prevent damage to the interior of the abrasive passage 6b. For example, the abrasive passage 6b communicates with the air passage 6c. Therefore, the interface between the abrasive passage 6b and the air passage 6c may be reinforced by placing a hard cover or coating thereon.

[0026] The air passage 6c is formed within the opening / closing mechanism main body 6a. Air supplied from the drive source M (fourth drive source M4) passes through the air passage 6c. This prevents the abrasive A from scattering around or clogging the opening / closing mechanism main body 6a when switching the supply or stop of the abrasive A. Furthermore, because the abrasive A is a hard material, a cover or coating may be placed on the surface of the air passage 6c to prevent damage to the inside of the air passage 6c. For example, the air passage 6c communicates with the inlet hole 6d and the outlet hole 6e. Therefore, the contact points of the air passage 6c with the inlet hole 6d and the outlet hole 6e may be reinforced by placing a hard cover or coating.

[0027] When the partition plate 7a of the first opening / closing part 7 moves forward, the partition plate 7a is inserted into the air passage 6c and blocks the abrasive passage 6b. This stops the supply of abrasive A from the first tank 2 to the second tank 3. The partition plate 7a is preferably plate-shaped. The air passage 6c desirably has a shape corresponding to the partition plate 7a.

[0028] The inlet hole 6d introduces air into the opening / closing mechanism main body 6a. Air supplied from the drive source M (fourth drive source M4) is introduced into the opening / closing mechanism main body 6a from the inlet hole 6d via an air hose or the like. The outlet hole 6e discharges air from the opening / closing mechanism main body 6a to the outside. The advancement of the partition plate 7a stops the supply of abrasive A. The retreat of the partition plate 7a supplies abrasive A. At this time, abrasive A that adheres to or scatters above the partition plate 7a or in the air passage 6c is discharged to the outside by air. This prevents abrasive A from clogging the opening / closing mechanism 6. The discharge hole 6e is connected to the first tank 2 via an air hose or the like, so that excess abrasive A can be circulated again.

[0029] The first opening / closing unit 7 temporarily switches between on and off the supply of abrasive A from the first tank 2 to the second tank 3. The first opening / closing unit 7 switches between opening and closing the abrasive passage 6b by moving the partition plate 7a forward or backward using the drive cylinder 7b. The partition plate 7a can reduce the height of the abrasive supplying device 1. Specifically, it is desirable that the abrasive supplying device 1 have a height that can be reached by an operator (for example, approximately 100 to 180 cm). Since the weight of the abrasive supplying device 1 increases as abrasive A accumulates, the partition plate 7a contributes to reducing the weight of the abrasive supplying device 1.

[0030] The drive cylinder 7b advances or retreats the partition plate 7a using air supplied from the drive source M (second drive source M2). The drive cylinder 7b has a piston 7c, a front chamber 7d, and a rear chamber 7e. The piston 7c advances or retreats when air is supplied from the drive source M (second drive source M2) to at least one of the front chamber 7d and the rear chamber 7e. For example, when air from the drive source M (second drive source M2) is supplied to the rear chamber 7e to advance the piston 7c, the partition plate 7a fixed to the front of the piston 7c advances. When air from the drive source M (second drive source M2) is supplied to the front chamber 7d to retreat the piston 7c, the partition plate 7a retreats. The first opening / closing unit 7 in this embodiment is of a cylinder type, but is not limited to this. The first opening / closing unit 7 may have any mechanism that allows it to move forward and backward.

[0031] The partition plate 7a is fixed to the tip of the piston of the drive cylinder 7b. When the drive cylinder 7b moves forward, the partition plate 7a is inserted into the air passage 6c, closing the abrasive passage 6b. This stops the supply of abrasive A.

[0032] The partition plate 7a may be configured to be in constant contact with the air passage 6c to prevent air from leaking from the air passage 6c when the partition plate 7a moves forward or backward within the air passage 6c. In this case, a sealing member or coating member may be formed on part or all of the tip of the partition plate 7a. This ensures that the inner surface of the air passage 6c and the outer surface of the partition plate 7a are in constant contact, maintaining airtightness within the air passage 6c.

[0033] The second opening / closing unit 8 secondarily switches on and off the supply of abrasive A from the first tank 2 to the second tank 3. The second opening / closing unit 8 has an outer member 8a and an inner member 8b on the outer periphery of the abrasive passage 6b. A gap is formed between the outer member 8a and the inner member 8b. When air is introduced into the air holes 8c formed in the outer member 8a, the inner member 8b converges inward, switching between opening and closing the abrasive passage 6b.

[0034] The outer member 8a and the inner member 8b form an abrasive passage 6b therein. The outer member 8a forms the abrasive passage 6b. The outer member 8a may have a cylindrical or polygonal shape, for example, but is preferably cylindrical. The inner member 8b is disposed on the inner periphery of the outer member 8a. The inner member 8b has expandability. The inner member 8b is preferably made of a material such as rubber. The inner member 8b expands toward the inside of the abrasive passage 6b by air supplied from the driving source M (third driving source M3). This closes the abrasive passage 6b and stops the supply of abrasive A from the first tank 2 to the second tank 3. Note that the entire inner member 8b does not need to be expandable. The inner member 8b may be composed of two types of material, one of which may be made of a hard material such as stainless steel or metal like the outer member 8a, and the other of which may be made of an expandable material such as rubber.

[0035] Air holes 8c are formed around the outer member 8a. Air supplied from the drive source M (third drive source M3) is introduced through the air holes 8c into the gap between the outer member 8a and the inner member 8b. Air in the gap between the outer member 8a and the inner member 8b is discharged to the outside through the air holes 8c.

[0036] The drive source M may operate independently for each function or may operate the abrasive supply device 1 as a whole. The drive source M shown in FIGS. 1 to 6 includes a first drive source M1, a second drive source M2, a third drive source M3, and a fourth drive source M4, which are individually operated. The first drive source M1 supplies air into the second tank 3 to supply the abrasive A to the abrasive nozzle 101. The second drive source M2 controls the first opening / closing unit 7 to start or stop the supply of the abrasive A from the first tank 2 to the second tank 3. The third drive source M3 controls the second opening / closing unit 8 to start or stop the supply of the abrasive A from the first tank 2 to the second tank 3. The fourth drive source M4 supplies air into the opening / closing mechanism main body 6a to prevent clogging and scattering of the abrasive A in the opening / closing mechanism 6.

[0037] Here, an abrasive supplying apparatus 1 of Modification 1 will be described with reference to Fig. 7. The driving source M of this modification centrally operates the first to fourth driving sources M1 to M4 of the embodiment. The abrasive supplying apparatus 1 of this modification has a first switching valve 9a, a second switching valve 9b, a third switching valve 9c, a fourth switching valve 9d, and a control device 10. The first switching valve 9a switches between supplying and stopping air into the second tank. The second switching valve 9b switches between advancing and retreating the partition plate 7a. The third switching valve 9c switches between supplying and stopping the abrasive A from the first tank 2 to the second tank 3 by the second opening / closing unit 8. The fourth switching valve 9d switches between supplying and stopping air into the opening / closing mechanism main body 6a. The control device 10 switches the various switching valves 9 according to the work process.

[0038] The control device 10 of this embodiment controls the amount and timing of supplying the abrasive A to the abrasive nozzle 101, and operates various elements. The control device 10 controls the drive sources M (first to fourth drive sources M1 to M4) and the switching valves 9 (first to fourth switching valves 9a to 9d). The control device 10 also controls the drive sources M and the switching valves 9 based on signals from various sensors (first tank upper limit sensor S1, first tank lower limit sensor S2, second tank upper limit sensor S3, and second tank lower limit sensor S4).

[0039] The second tank 3 supplies the abrasive A to the abrasive nozzle 101. Therefore, the space between the abrasive nozzle 101 and the second tank 3 (the inside of the high-pressure hose, etc.) is pressurized. Therefore, the second tank 3 is filled with air supplied from the drive source M (first drive source M1).

[0040] In Modification 1 shown in FIG. 7, a compressed air holding tank 12 is disposed between the driving source M (first driving source M1) and the second tank 3. The compressed air holding tank 12 holds spare compressed air. This allows the amount of air to be replenished when the air pressure in the second tank 3 does not increase.

[0041] Furthermore, a third opening / closing unit 11 may be disposed between the second tank 3 and the abrasive nozzle 101. This prevents the air pressure in the high-pressure hose from the second tank 3 to the abrasive nozzle 101 from becoming unable to increase, and makes it possible to maintain an appropriate pressure in the second tank 3. The third opening / closing unit 11 has a mechanism similar to that of the first opening / closing unit 7 and the second opening / closing unit 8, for example.

[0042] In Modification 2 shown in Fig. 8, the central axis L1 of the first tank 2 is misaligned with the central axis L2 of the second tank 3. To make the abrasive supply device 1 more compact, it is desirable that the opening and closing mechanism 6 be housed inside the device. When the supply and stop of the abrasive A are switched by advancing and retracting the partition plate 7a, as in the first opening and closing unit 7, a compact configuration can be achieved by locating the partition plate 7a on the inside. Furthermore, the first tank 2 can accommodate a larger volume of abrasive A than the second tank 3. For example, when the first tank 2 is filled to its upper limit with abrasive A, pressure equivalent to the weight of the abrasive A is applied to the bottom of the first tank 2, causing the surrounding area to become nearly solidified. By offsetting the central axis L1 of the first tank 2 from the central axis L2 of the second tank 3, the abrasive A can be dropped into the second tank 3 from a position offset from directly below the first tank 2, thereby slowing the drop speed of the abrasive A, rather than dropping it into the second tank 3 from directly below the first tank 2.

[0043] As shown in Fig. 9, the abrasive supply device 1 is used as part of an abrasive water jet machining device 100. The abrasive water jet machining device 100 ejects high-pressure water generated by a high-pressure pump P from an abrasive nozzle 101 together with an abrasive A supplied from the abrasive supply device 1. This allows cutting, milling, peeling, chipping, etc. of the workpiece W to be machined. The liquid ejected from the abrasive nozzle 101 is stored in a tank 102. The abrasive nozzle 101 can also process the workpiece W while moving in the X, Y, and Z directions using a mechanism (not shown) that can move along the X, Y, and Z axes.

[0044] The abrasive water jet machining apparatus 100 has a first flow path H1 and a second flow path H2. The first flow path H1 connects the second tank 3 and the abrasive nozzle 101. The second flow path H2 connects the high-pressure pump P and the abrasive nozzle 101.

[0045] The abrasive water jet machining apparatus 100 may have an abrasive supply on-off valve 90a and a high-pressure water supply on-off valve 90b. The abrasive supply on-off valve 90a is disposed on the first flow path H1. The abrasive supply on-off valve 90a starts or stops the intake of abrasive A supplied from the abrasive supply apparatus 1 into the abrasive nozzle 101. The high-pressure water supply on-off valve 90b is disposed on the second flow path H2. The high-pressure water supply on-off valve 90b starts or stops the intake of high-pressure water supplied from the high-pressure pump P into the abrasive nozzle 101.

[0046] A method of using the abrasive supplying device of this embodiment will be described below. First, in the preparation process, the worker checks the amount of abrasive A contained inside the first tank 2 and the second tank 3. If it is the first time the worker is using the machine, he or she checks to see if there is any abrasive A in either tank. By turning on the driving source M, the opening and closing mechanism 6 is made operable. At this time, the opening and closing mechanism 6 (the first opening and closing unit 7 and the second opening and closing unit 8) is in a closed state, and the supply of abrasive A is stopped.

[0047] An operator places abrasive A into first tank 2. Alternatively, when continuously automating the process, a conveying device may be automated from the storage location of purchased abrasive A and connected to first tank 2. Alternatively, a crane may be placed above abrasive supplying device 1, and bags containing abrasive A may be sequentially transferred to the top by the conveying device, thereby supplying abrasive A in stages.

[0048] When the drive source M (second drive source M2, third drive source M3) is driven, the opening / closing mechanism 6 supplies the abrasive A from the first tank 2 to the second tank 3. When the abrasive amount reaches the second tank abrasive amount reference line (upper limit) C3 in the second tank 3, the opening / closing mechanism 6 closes, and the supply of the abrasive A from the first tank 2 to the second tank 3 is stopped.

[0049] Next, in the working process, the amount of abrasive A to be sprayed from the abrasive nozzle 101 is determined, and the operating conditions of the abrasive supplying device 1 are set. Specifically, the supply amount of abrasive A from the first tank 2 to the second tank 3 is set so as not to be excessive or insufficient relative to the discharge amount of abrasive A pumped from the second tank 3. When the amount of abrasive A in the second tank 3 reaches the second tank abrasive amount reference line (lower limit) C4, the opening / closing mechanism 6 is opened and abrasive A is supplied up to the second tank abrasive amount reference line (upper limit) C3. The opening / closing span of the opening / closing mechanism 6 is set according to the discharge amount of abrasive A, and abrasive A is supplied continuously. In addition, by using the second tank abrasive quantity reference line (upper limit) C3 and the second tank abrasive quantity reference line (lower limit) C4 as reference lines, the air pressure required to pressurize the abrasive A can be stabilized without storing too much abrasive A in the second tank 3 at one time, and abrasive A can be supplied continuously.

[0050] The amount and timing of supply of the abrasive A may be changed in advance directly in the setting section of the drive source M or the control device 10, or may be remotely operated by displaying a setting screen on a tablet.

[0051] Next, in the processing step, the abrasive water jet processing device 100 is operated. A water jet mixed with abrasive A is sprayed from the abrasive nozzle 101 to perform processing such as cutting and peeling on various raw materials. In order to steadily supply abrasive A, the abrasive supply device 1 is operated. Abrasive A is pressure-fed from the second tank 3, and abrasive A is sequentially supplied from the first tank 2 to the second tank 3. This allows the amount of abrasive A supplied to the abrasive nozzle 101 to be adjusted so that it is neither too much nor too little.

[0052] Finally, after the processing step is completed, the operation of the abrasive supplying device 1 is stopped by performing the steps in reverse to those of the preparation step.

[0053] It goes without saying that the present invention is not limited to the above-described embodiment, and that the present invention can be modified as appropriate within the scope of the gist of the invention. [Explanation of symbols]

[0054] 1 Abrasive material supply device 2. First Tank 3 Second Tank 4 Support part 5 Lid 6 Opening and closing mechanism 6a Opening and closing mechanism body 6b Abrasive material passage 6c Air passage 6d Introduction hole 6e Exhaust hole 7 First opening and closing section 7a Partition 7b Drive cylinder 7c Piston 7d Antechamber 7e rear chamber 8 Second opening and closing section 8a Outer member 8b Inner member 8c Air vent 9a First switching valve 9b Second switching valve 9c Third switching valve 9d Fourth switching valve 10 Control device 11 Third opening and closing section 12 Compressed Air Holding Tank 100 Abrasive water jet processing equipment 101 Abrasive nozzle 102 Tank M Drive source M1 First driving source M2 Second driving source M3 Third driving source M4 Fourth driving source S1 First tank upper limit sensor S2 First tank lower limit sensor S3 Second tank upper limit sensor S4 Second tank lower limit sensor C1 First tank abrasive amount reference line (upper limit) C2 First tank abrasive amount reference line (lower limit) C3 Second tank abrasive amount reference line (upper limit) C4 Second tank abrasive amount reference line (lower limit) L1 Central axis of the first tank L2 Central axis of the second tank H1 First flow path H2 Second flow path

Claims

1. a first tank containing an abrasive; a second tank disposed below the first tank and configured to accommodate the abrasive supplied from the first tank; an abrasive passageway for moving the abrasive from the first tank to the second tank; an opening / closing mechanism for switching the opening and closing of the abrasive passage; and The opening and closing mechanism is A drive cylinder; a partition plate that can be advanced or retreated by the drive cylinder; a first opening / closing unit having an outer member disposed on the outer periphery of the abrasive passage and having an air passage hole through which air can be introduced; an inner member disposed on the inner periphery of the outer member at the outer periphery of the abrasive passage, the inner member converging inward when air is introduced into the air passage hole, and switching between opening and closing of the abrasive passage; and a second opening / closing unit having Abrasive supply device used in abrasive water jet processing equipment.

2. The opening and closing mechanism is An opening / closing mechanism main body; an introduction hole for introducing air into the opening / closing mechanism body; a discharge hole for discharging air to the outside of the opening / closing mechanism body; 2. An abrasive supply device for use in an abrasive water jet machining device according to claim 1, comprising:

3. The device further includes a switching valve that switches between supplying and stopping air for switching between opening and closing of the first opening / closing unit and the second opening / closing unit.

3. An abrasive supply device for use in the abrasive water jet machining device according to claim 1 or 2.

4. The central axis of the first tank is offset from the central axis of the second tank.

3. An abrasive supply device for use in the abrasive water jet machining device according to claim 1 or 2.

5. a third opening / closing portion for controlling the discharge of the abrasive from the second tank; 3. An abrasive supply device for use in the abrasive water jet machining device according to claim 1 or 2.

6. further comprising a compressed air holding tank for maintaining a constant pressure in the second tank; 3. An abrasive supply device for use in the abrasive water jet machining device according to claim 1 or 2.

7. The abrasive supply device according to claim 1 or 2; a high-pressure pump for generating high-pressure water; an abrasive nozzle that sprays the abrasive supplied from the abrasive supply device together with high-pressure water supplied from the high-pressure pump; An abrasive water jet machining device having:

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