JP6941299B2 - Surface treatment equipment and surface treatment method - Google Patents

Description

The present invention relates to a surface treatment apparatus and a surface treatment method using the surface treatment apparatus.

The surface treatment device injects an injection material (shot, grid, abrasive grains, etc.) from the nozzle assembly toward the workpiece together with compressed air to perform surface treatment (blast processing, shot peening processing) of the workpiece. The nozzle assembly mounted on the surface treatment device is known to be a pressure type or a suction type.

The pressurized nozzle assembly is a type in which a pressure vessel loaded with an injection material is pressurized with compressed air or the like, the injection material is sent to a compressed air stream, and the injection material is injected together with the compressed air as a solid air two-phase flow. (Refer to Patent Document 1.) Compared with the suction type nozzle assembly, the injection material can be injected at a high speed, so that the processing ability is high in surface treatment and deeper in shot peening. Compressive residual stress can be applied, and in film formation, a film having higher adhesion can be formed. However, the pressurized nozzle assembly has a problem that the injection amount and the injection time of the injection material are limited by the volume of the pressure tank, so that the injection material cannot be continuously injected for a long time.

The suction type nozzle assembly is a type in which the injection material is sucked by the suction force generated by the compressed air flow introduced into the air nozzle and is injected together with the compressed air as a solid air two-phase flow. (Refer to Patent Document 2.) Since it is not necessary to seal the container for storing the injection material unlike the pressurized type, there is an advantage that the injection material can be continuously injected. However, since the suction type nozzle assembly sucks the injection material in the atmosphere together with the air, a pressure loss occurs, and therefore, there is a problem that the injection speed of the injection material is slower than that of the pressure type nozzle assembly. .. In order to increase the injection speed, it is conceivable to increase the injection speed of the injection material by increasing the pressure of the compressed air to compensate for the pressure loss of the compressed air. However, since a stronger compressed air supply source is required, it leads to an increase in equipment cost and an increase in operating energy of the compressed air supply source.

Japanese Unexamined Patent Publication No. 02-160514 Japanese Unexamined Patent Publication No. 08-267360

The present invention has been made to solve the above-mentioned problems of the prior art, and is a surface treatment capable of efficiently injecting an injection material toward an workpiece to treat the surface of the workpiece. It is an object of the present invention to provide an apparatus and a surface treatment method using the surface treatment apparatus.

One aspect of the present invention is a surface treatment apparatus for treating the surface of a work piece by causing an injection material mixed with compressed air to collide with a work piece as a solid air two-phase flow. The surface treatment apparatus includes a nozzle assembly for injecting a solid air two-phase flow, and a housing in which the nozzle assembly is housed and forms a surface treatment chamber inside. The nozzle assembly includes a nozzle body and an air nozzle. The nozzle body includes an injection material suction port for sucking the injection material and an ejection port for ejecting the sucked injection material together with compressed air in a mixing chamber provided inside the nozzle assembly. At least one end of the air nozzle is inserted into the nozzle body, and the other end is connected to a compressed air generation source that generates compressed air. A heating mechanism for heating the compressed air is provided in the air supply path from the compressed air generation source to the air nozzle.

Another aspect of the present invention is a surface treatment method using these surface treatment devices. The surface treatment method includes the following steps.
(1) A step of heating compressed air generated by a pressure air source.
(2) A step of injecting compressed air inside the nozzle body to create a negative pressure in the mixing chamber provided inside the nozzle body.
(3) A step of sucking the injection material into the mixing chamber through a path from the injection material suction port connected to the tank in which the injection material is stored to the mixing chamber and mixing it with compressed air.
(4) A step of injecting the mixed compressed air and the injection material as a solid air two-phase flow through a path from the mixing chamber to the injection port.
Then, in the step (1), the compressed air is heated to 100 to 500 ° C.

By heating the compressed air, the flow velocity of the compressed air becomes faster. In addition, the abrasive grains may agglomerate depending on their properties and atmosphere, but the agglomerates can be crushed by weakening the adhesive force between the particles by heating. Due to these synergistic effects, the injection material can be efficiently injected, so that the surface treatment capacity can be improved.

One embodiment of the present invention is a path for compressed air in an air nozzle. The air nozzle is provided with a compressed air injection port at the tip, and the path from the side connected to the compressed air supply source to the compressed air injection port is toward the reduced diameter end located on the compressed air injection port side. A first accelerating portion that continuously reduces the diameter and a second accelerating portion that continuously expands the diameter from the reduced diameter end toward the enlarged diameter end on the compressed air injection port side may be included. Compressed air is accelerated by diameter reduction and then further by diameter expansion. That is, since the flow velocity of the compressed air is increased by this configuration, the flow velocity of the solid air two-phase flow can be increased, and the surface treatment capacity can be improved.

In one embodiment of the present invention, the distance of the second accelerating portion may be equal to or greater than the distance of the first accelerating portion. By allowing the compressed air passing through the second accelerating portion to flow along the wall surface, it is possible to accelerate efficiently.

One embodiment of the present invention may further include a mechanism for cooling the workpiece. Since the influence of the high temperature of the work piece due to the heating of the solid air two-phase flow can be suppressed, a wide range of surface treatments can be performed.

According to one aspect or one embodiment of the present invention, the flow velocity of the solid air two-phase flow can be increased and the agglomeration of the propellant can be prevented, so that the surface treatment can be efficiently performed.

It is a front view which shows the surface treatment apparatus of one Embodiment of this invention. It is a top view which shows the mounting table mounted on the surface treatment apparatus of one Embodiment of this invention. It is a front view which shows the nozzle assembly mounted on the surface treatment apparatus of one Embodiment of this invention. It is a flow figure which shows the surface treatment method of one Embodiment of this invention. It is a schematic diagram which shows the mode of moving to the work in the surface treatment apparatus of one Embodiment of this invention. The cross-sectional shape of the work after the surface treatment by the surface treatment method of one embodiment of the present invention is shown. It is a graph which shows the influence of the temperature of compressed air in the surface treatment apparatus of one Embodiment of this invention.

Hereinafter, the surface treatment apparatus according to the embodiment of the present invention will be described with reference to the accompanying drawings. In the text, "up / down / left / right direction" refers to the direction in the figure unless otherwise specified.

FIG. 1 is a front view showing a part of the surface treatment apparatus 01 according to the embodiment cut off. The surface treatment device 01 is a device that projects a jetting material onto a work W (workpiece) made of fiber reinforced plastic to form holes in the work W. As shown in FIG. 1, the surface treatment device 01 includes a housing 10, a fixed quantity supply mechanism 20, a separation mechanism 30, a suction mechanism 40, a control device 50, a nozzle assembly 60, and a heating mechanism 70.

The housing 10 defines a processing chamber R inside the housing 10. A door 11 is provided on the front surface of the housing 10, and an operator can access the processing chamber R by opening the door 11. The processing chamber R is provided with a nozzle fixing jig 12, a processing table 13, and a moving mechanism 14.

The nozzle fixing jig 12 is a mechanism for holding the nozzle assembly 60, and the nozzle assembly 60 can be moved along the height direction. Therefore, the nozzle fixing jig 12 is configured so that the distance between the nozzle assembly 60 and the work W can be freely adjusted.

The moving mechanism 14 is provided on a pedestal 15 provided at the bottom of the housing 10, and is arranged below the nozzle assembly 60. In one embodiment, the moving mechanism 14 may be a plate-like body having a large number of through holes formed therein. By forming such a through hole in the moving mechanism 14, the injection material injected from the nozzle assembly 60 can be passed toward the bottom of the housing 10.

A processing table 13 is provided on the moving mechanism 14, and supports the work W placed on the processing table 13. It is sufficient that the work W can be placed on the processing table 13, but since the solid air two-phase flow is in a heated state as described later, a function of cooling the work W may be provided. FIG. 2 is a plan sectional view of the processing table used in one embodiment. In FIG. 2, a cooling pipe 13a is stretched inside the processing table 13 and a cooling medium (for example, water) is allowed to flow through the cooling pipe to cool the work W.

The moving mechanism 14 can horizontally convey the processing table 13 and the work W supported on the processing table 13 by, for example, the driving force of the motor. For example, the moving mechanism 14 is an XY stage that extends the work W in the horizontal direction and moves the work W along the X and Y directions (see FIG. 5) that are orthogonal to each other.

A fixed quantity supply mechanism 20 is provided above the processing chamber R. The fixed quantity supply mechanism 20 includes a storage hopper 21 and a transport path 22, and supplies the injection material in the storage hopper 21 to the nozzle assembly 60 in a fixed quantity via the transport path 22. The structure of the fixed quantity supply mechanism 20 is not limited as long as a constant amount of injection material can be supplied to the nozzle assembly 60. For example, as the fixed quantity supply mechanism 20, a screw feeder, a vibration feeder, or a table feeder can be used. In the embodiment shown in FIG. 1, a screw feeder is used as the fixed quantity supply mechanism 20.

A separation mechanism 30 is provided above the storage hopper 21 of the fixed quantity supply mechanism 20. The separation mechanism 30 is connected to the storage hopper 21 of the fixed quantity supply mechanism 20. The separation mechanism 30 has a substantially inverted pyramid shape, collects used injection material, and classifies it into reusable injection material and dust. One end of the first transport pipe P1 is connected to the separation mechanism 30. The other end of the first transport pipe P1 is connected to the bottom of the housing 10. Therefore, the space in the processing chamber R and the space in the fixed quantity supply mechanism 20 are continuous via the first transport pipe P1. In the embodiment shown in FIG. 1, a cyclone type classifier is used as the separation mechanism 30, but any other classifier such as a wind power type classifier or a screen type classifier may be used as the separation mechanism 30. Can be done.

Further, one end of the second transport pipe P2 is connected to the separation mechanism 30. The other end of the second transport pipe P2 is connected to the suction mechanism 40. The suction mechanism 40 is a mechanism for making the processing chamber R a negative pressure so that the injection material does not leak to the outside of the processing chamber R and sucking the particles including the injected injection material. The suction mechanism 40 collects light particles (injection material having a size unsuitable for reuse, cutting powder of work W) classified by the separation mechanism 30 (cyclone type classifier) via the second transport pipe P2. do. Further, the suction mechanism 40 has a function of creating a negative pressure in the internal space of the separation mechanism 30 and transferring the used injection material collected at the bottom of the housing 10 to the separation mechanism 30.

The control device 50 is a computer including a processor, a storage unit, an input device, a display device, and the like, and controls each unit of the surface treatment device 01. In one embodiment, the control device 50 sends a control signal to the moving mechanism 14, the fixed quantity supply mechanism 20, the suction mechanism 40, the heating mechanism 70, the solenoid valve VL1 and the valve VL2, and operates the moving mechanism 14, the fixed quantity supply mechanism 20. , The operation of the suction mechanism 40, the opening and closing of the solenoid valve VL1, and the like are controlled. As the control device, various arithmetic units such as a personal computer, motion controllers such as a programmable logic controller (PLC) and a digital signal processor (DSP), a high-performance mobile terminal, a high-performance mobile phone, and the like can be used.

The nozzle assembly 60 is a mechanism for injecting an injection material onto the work W, and as shown in FIG. 3, includes a nozzle body 61 and an air nozzle 62 that injects compressed air into the nozzle body 61. ing.

The nozzle body 61 includes a nozzle holder 61a and a cylindrical injection nozzle 61b that is inserted and fixed from one end side (lower end surface side in FIG. 3) of the nozzle holder 61a. The air nozzle 62 is inserted and fixed to the other end side (upper end surface side in FIG. 3) of the nozzle holder 61a of the nozzle body 61. A mixing chamber 64 that forms an internal space of the nozzle body 61 is provided in the vicinity of the lower end of the air nozzle 62 inside the nozzle body 61 and the upper end of the injection nozzle 61b.

An injection material suction port 63 for sucking the injection material is provided on the upper portion of the nozzle holder 61a, and is connected to the fixed quantity supply mechanism 20 via the injection material hose H2. Further, a first path F1 which is a path from the injection material suction port 63 to the mixing chamber 64 is formed.

The injection nozzle 61b is formed with a circular injection port 65 for injecting a solid two-phase flow at the lower end thereof, and further, a second path F2 which is a path from the mixing chamber 64 to the injection port 65 is formed. ing.

In the nozzle body 61, the injection material suction port 63, the first path F1, the mixing chamber 64, the second path F2, and the injection port 65 are communicated with each other.

The air nozzle 62 has a cylindrical shape, a third path F3 which is a path for compressed air is formed inside the air nozzle 62, and a compressed air injection port 62a is provided at the tip (lower end in FIG. 3) where the compressed air is injected. A compressed air introduction port 62b is provided at the other end (upper end in FIG. 3). The compressed air introduction port 62b and the compressed air injection port 62a communicate with each other to form a second path F2 through which the compressed air flows. The second path F2 in one embodiment includes a compressed air introduction section 62c having a continuous diameter, a first acceleration section 62d that communicates with the compressed air introduction section 62c and gradually reduces the diameter toward the tip, and the compressed air introduction section 62d. A second accelerating portion 62e that communicates with the first accelerating portion 62d and gradually expands in diameter toward the compressed air injection port 62a is provided. The compressed air introduction unit 62c, the first acceleration unit 62d, and the second acceleration unit 62e are arranged on the same axis.

The compressed air introduction port 62b is connected to the compressed air supply source C via the air pipe H1, and the compressed air is injected from the compressed air injection port 62a by the operation of the compressed air supply source. The compressed air injection port 62a is inserted and fixed in the nozzle holder 61a so as to be located in the mixing chamber 64. The compressed air introduced from the compressed air introduction unit 62c is compressed and accelerated by the first acceleration unit 62d, and then gradually expanded by the second acceleration unit 62e to be further accelerated, and the compressed air is injected. It is injected from the mouth 62a. Since the compressed air can be injected at high speed, the injection speed of the solid air two-phase flow injected from the injection port 65 is also increased. As a result, the surface treatment capacity is improved, so that the surface treatment can be performed efficiently. A compressor C is connected to the air nozzle 62 via an air pipe H1. In one embodiment, a solenoid valve VL1 and a valve VL2 may be provided between the air nozzle 52 and the compressor C.

The flow of compressed air that has passed through the first acceleration unit 62d can be most efficiently accelerated by flowing along the wall surface of the second acceleration unit 62e.

When the compressed air is injected from the compressed air injection port 62a, the injection flow travels straight while entraining the surrounding air, so that the mixing chamber 64 becomes a negative pressure and a suction force is generated. By this suction force, the injection material stored in the storage hopper 21 is sucked into the mixing chamber 64 through the first path F1 via the transport path 22 and the injection material hose H2. The injection material that has reached the mixing chamber 64 is mixed with compressed air, passes through the second path F2, and is injected from the injection port 65 toward the work W as a solid air two-phase flow. The injection material is sucked from the injection material suction port 63 toward the mixing chamber 64. The propellant that has reached the mixing chamber 64 is mixed with compressed air, and the mixed compressed air and propellant are jetted as a more solid two-phase flow. Here, the suction force varies in magnitude depending on the distance between the compressed air injection port 62a and the inner wall surface of the injection nozzle 61b. Therefore, the air nozzle 62 is adjusted by moving it in the vertical direction so as to obtain the optimum suction force, which is not shown. Fix it to the nozzle holder 61a with a bolt or the like. However, if the distance is too short, the flow of the mixed injection material moving to the injection nozzle 61b is hindered. In the air nozzle 62 of one embodiment, the compressed air is sufficiently accelerated by the first acceleration unit 62d and the second acceleration unit 62e, and the injection speed is high, so that the force for entraining the surrounding air is improved. As a result, the suction force generated in the mixing chamber 64 becomes stronger, so that a sufficient suction force for sucking the injection material can be obtained even if the distance between the compressed air injection port 62a and the wall surface of the mixing chamber 64 is increased. can. That is, by using the air nozzle 62 of one embodiment, it is possible to improve the injection speed of the solid air two-phase flow and increase the injection amount of the injection material, so that the efficiency of the surface treatment can be improved.

Since the nozzle assembly 60 having the configuration of one embodiment can continuously inject the injection material, the work W can be continuously processed for a long time. If the injection speed of the solid air two-phase flow and the suction force of the injection material are satisfied, another embodiment of the third path F3 may be used. In another embodiment, instead of the second accelerating unit 62e, a rectifying unit that communicates with the first accelerating unit 62d and has the same diameter toward the compressed air injection port 62a may be provided.

The injection material injected from the nozzle includes metal or non-metal shots, grids, cut wires, ceramic particles (alumina, silicon carbide, zircon, etc.), natural stone particles (emery, silica stone, diamond, etc.). ), Plant-based particles (walnut shell, peach seed, apricot seed, etc.), resin-based particles (nylon, melamine, urea, etc.) and the like are exemplified.

The heating mechanism 70 is connected to the air supply path from the compressed air supply source C to the air nozzle 62. The structure of the heating mechanism 70 is not particularly limited as long as the compressed air can be heated to a predetermined temperature. In one embodiment, the heating element is fixed around the tube through which compressed air can pass.

Next, a method of performing surface treatment using the surface treatment device 01 of one embodiment will be described.

<S1: Preparation of surface treatment device>
In the step (S1) of preparing the surface treatment apparatus 01, (a) setting of the injection material, (b) adjustment of the injection speed of the solid air two-phase flow, (c) setting of the work W, and (d) the nozzle assembly 60. The distance between the work W and the work W is adjusted, (e) the operating conditions of the moving mechanism are set, (f) the operating conditions of the fixed quantity supply mechanism 20 are set, and (g) the heating temperature is set.

(A) Setting of injection material First, the suction mechanism 40 is operated to suck the processing chamber R. Next, the door 11 is unlocked to open the door 11, and for example, an operator throws a predetermined amount of the injection material into the processing chamber R. Next, the suction force of the suction mechanism 40 transfers the injection material to the storage hopper 21 of the fixed quantity supply mechanism 20 via the first transport pipe P1 and the separation mechanism 30. After that, the door 11 is closed and locked. Since the inside of the processing chamber R becomes a negative pressure due to the suction of the suction mechanism 40, outside air flows into the processing chamber R from a suction hole (not shown) provided so as to communicate with the outside.

(B) Adjustment of injection speed of solid air two-phase flow For example, the control device 50 of the surface treatment device 01 is operated, and the solenoid valve VL1 provided in the path for supplying compressed air to the nozzle assembly 60 is opened. It is set and the fixed quantity supply mechanism 20 is set to "ON". With such a setting, the injection material is supplied to the nozzle assembly 60 and injected from the nozzle assembly 60. When the injection material is injected from the nozzle assembly 60, the opening degree of the valve VL2 that adjusts the supply pressure of the compressed air is adjusted, and the injection speed of the injection material is adjusted.

(C) Work setting After adjusting the injection speed, the control device 50 is operated to set the solenoid valve VL1 to “closed” and the fixed quantity supply mechanism 20 to “OFF”. With such a setting, the injection of the injection material from the nozzle assembly 60 is stopped. After that, the door 11 is opened, and the work W is placed and fixed on the processing table 13.

(D) Adjustment of the distance between the nozzle assembly and the work The distance and angle between the nozzle assembly 60 and the work W are adjusted by operating the nozzle fixing jig 12 next to the surface treatment device 01. .. After that, the door 11 is closed and locked.

(E) Setting of operating conditions of the moving mechanism The operating conditions of the moving mechanism 14 are the locus of movement of the moving mechanism 14 (distances in the X and Y directions in FIG. 5), the moving speed, the number of scans, and the like. The control device 50 is operated and these conditions are input.

(F) Setting of operating conditions of the fixed quantity supply mechanism A predetermined amount of injection material is supplied to the nozzle assembly 60 by the fixed quantity supply mechanism 20. If the supply amount is large, the surface treatment capacity is improved, but if it is too large, the injection material stays in the injection material hose H2 or the mixing chamber 64, and the injection material cannot be injected gradually. The control device 50 is operated, and the operating conditions of the fixed quantity supply mechanism are input so as to obtain an appropriate injection material supply amount.

(G) Setting of heating temperature A thermometer T is arranged in the path between the heating mechanism 70 and the compressed air supply source C, and the temperature of the compressed air can be monitored. The control device 50 is operated, and the operating conditions of the fixed quantity supply mechanism are input so that the temperature of the compressed air becomes a predetermined temperature. If the temperature of the compressed air is too low, the efficiency will not be improved by heating, and if it is too high, the propellant may be denatured (softening, surface oxidation, etc.). Set appropriately in consideration of these. For example, when a ceramic injection material is used, it may be selected from the range of 100 to 500 ° C.

<S2: Surface treatment process>
In the surface treatment step (S3) for performing the surface treatment, when the control device 50 is operated, a signal for opening the solenoid valve VL1 is first emitted, and compressed air is supplied to the nozzle assembly 60. Then, an operating signal is emitted to turn the heating means "ON". When the temperature of the compressed air rises to a predetermined temperature, a signal for turning on the fixed quantity supply mechanism 20 is issued, and the injection material is injected from the nozzle assembly 60. Next, a signal for turning the moving mechanism 14 "ON" is issued, and the moving mechanism 14 operates so that the work W moves in the horizontal direction (XY direction in FIG. 5). For example, the operation of scanning the work W by a predetermined distance in the + Y direction → scanning by a predetermined distance (pitch) in the + X direction → scanning by a predetermined distance in the −Y direction → scanning by a predetermined distance (pitch) in the + X direction is repeated. Then, as shown in FIG. 5, the injection region A moves so as to draw a comb-shaped locus T with respect to the work W. As a result, the propellant is collided with the entire surface of the work W substantially uniformly. In one embodiment, this operation may be performed a plurality of times. The injection port of the nozzle assembly 60 may have a rectangular flat shape. Since the injection region A can be increased, the efficiency of the surface treatment of the work W can be improved.

Here, since the compressed air is heated in the surface treatment method of one embodiment, the injection speed of the solid air two-phase flow can be increased as compared with the conventional surface treatment method. Since the improvement of the injection speed leads to the improvement of the surface treatment efficiency, the surface treatment method of one embodiment is superior in surface treatment ability as compared with the conventional surface treatment method. On the other side, when it is desired to obtain the same solid air two-phase flow injection speed, the flow rate from the compressed air supply source can be reduced by the surface treatment method of one embodiment, so that the compressed air supply source C is used. It can be miniaturized, or the energy required to operate the compressed air supply source C can be reduced.

Further, in the conventional surface treatment method, the injection material may be injected in an agglomerated state due to the influence of the ambient humidity or the moisture contained in the compressed air. The surface treatment with the agglomerated injection material leads to a variation in the degree of surface treatment in each work W when a plurality of work Ws are surface-treated. Since the compressed air is heated in the surface treatment method of one embodiment, the moisture in the compressed air is removed. Further, even if the propellant is supplied to the mixing chamber 64 in a state of being aggregated due to the influence of ambient humidity, the cohesive force is weakened by heat, so that it is being mixed with compressed air or in a solid air two-phase flow. This agglomeration is crushed. Therefore, in the surface treatment method of one embodiment, it is possible to prevent the injection material from colliding with the work in an agglomerated state, so that the reliability of the surface treatment for the work W is improved.

By heating the compressed air, the solid air two-phase flow is also heated. If there is concern about damage to the work W due to the heated solid air two-phase flow, the surface treatment may be performed while cooling the work W by flowing a cooling medium through the cooling pipe 13a.

<S3: Recovery process>
In the step (S3) of collecting the work W after the surface treatment, when the operation of the set moving mechanism 14 is completed, the control device 50 receives a signal to turn the heating mechanism 70 “OFF” and the fixed quantity supply mechanism 20 “OFF”, respectively. More output, heating is stopped, and injection of the propellant is stopped. At this time, since the compressed air is still supplied to the nozzle assembly 60, the nozzle assembly 60 is cooled. This cooling step is an appropriately provided step and may be omitted. When the nozzle assembly 60 is cooled, a signal for closing the solenoid valve VL1 is output from the control device 50, and the supply of compressed air to the nozzle assembly 60 is stopped. After that, the door 11 is unlocked, the door 11 is opened, and the work W is removed from the processing table 13. Then, after removing the propellant and dust adhering to the work W by air blow or the like, the work W is taken out of the processing chamber R, and a series of surface treatments is completed.

Next, the result of surface treatment by the surface treatment method of one embodiment will be described. In the following description, the result of selecting blasting as the surface treatment and blasting with the float glass plate as the work W will be described.

The blasting conditions are as follows.
Injection material: Alumina (average particle size d50 = 25 μm)
Injection pressure: 0.6MPa
Injection material supply amount: 200g / min
Distance between nozzle and workpiece: 2.5 mm
Work speed: 200 mm / sec
Compressed air temperature: room temperature, 200 ° C

The processed cross section of the work W after blasting was observed with a surface roughness / contour shape composite measuring machine, and the processing depth was measured.

The results are shown in FIG. FIG. 6 (A) shows a cross-sectional shape when blasting is performed without heating the compressed gas (room temperature), and FIG. 6 (B) shows a cross-sectional shape when compressed air is heated to 200 ° C. and blasted. Is. When blasting with compressed air at room temperature, it was processed to a depth of about 10 μm, whereas when blasting with compressed air heated to 200 ° C, it was processed to a depth of about 30 μm. .. That is, it was shown that the blasting ability was improved by heating the compressed air.

Next, the effect of the temperature of the compressed air on the injection speed was investigated. Compressed air was supplied to the air nozzle 62, and the flow velocity in the vicinity of the compressed air injection port 62a (referred to as the injection speed from the compressed air injection port 62a) was measured with a Pitot tube. The compressed air was adjusted to 20 ° C. (room temperature) to 500 ° C.

The results are shown in FIGS. 7 (A) and 7 (B). FIG. 7A shows the effect of the temperature of the compressed air on the injection speed of the compressed air. The horizontal axis is the pressure of the compressed air at the time of injection (hereinafter referred to as the injection pressure), and the vertical axis is the compressed air injection port. The injection speed from 62a. It can be seen that the injection speed is increased by heating the compressed air regardless of the injection pressure.

FIG. 7B shows the rate of increase in the injection speed at each temperature with respect to the case where the temperature of the compressed air is room temperature. Similar to FIG. 6A, the horizontal axis represents the injection pressure and the vertical axis represents the injection speed. At 50 ° C., the rate of increase was higher than that of room temperature, but the rate of increase was less than 110% with respect to any injection pressure, and the effect of improving the injection speed by heating was small. Further, it can be seen that the effect of increasing the injection speed is smaller at 500 ° C. than at 400 ° C.

In the examples, blasting is selected and described as the surface treatment, but the surface treatment apparatus and surface treatment method of one embodiment can also be applied to the shot peening treatment.

01 Surface treatment device 10 Housing 20 Quantitative supply mechanism 30 Separation mechanism 40 Suction mechanism 50 Control device 60 Nozzle assembly 70 Heating mechanism A Injection area C Compressed air supply source F1 to F3 First to third paths H1 Air piping H2 Injection Material hose P1, P2 First and second transport pipes R Processing chamber T locus VL1 Solenoid valve VL2 Valve W work

Claims (5)

A surface treatment device for treating the surface of a work piece by colliding the propellant mixed with compressed air as a solid air two-phase flow with the work piece.
The nozzle assembly for injecting the solid air two-phase flow and
A housing in which the nozzle assembly is housed and a surface treatment chamber is formed inside,
Including
The nozzle assembly includes a nozzle body having an injection material suction port for sucking injection material and a nozzle body for ejecting the sucked injection material together with compressed air in a mixing chamber provided inside the nozzle assembly, and at least one end side thereof. An air nozzle inserted into the nozzle body, including an air nozzle connected to a compressed air generation source that generates compressed air at the other end.
A heating mechanism for heating the compressed air is provided in the air supply path from the compressed air generation source to the air nozzle .
A surface treatment apparatus comprising a mechanism for cooling the work piece in order to perform surface treatment while cooling the work piece. The air nozzle is provided with a compressed air injection port at the tip, and the path from the side connected to the compressed air supply source to the compressed air injection port is toward the reduced diameter end located on the compressed air injection port side. It is characterized by including a first accelerating portion that continuously reduces the diameter, and a second accelerating portion that continuously expands the diameter from the reduced diameter end toward the enlarged diameter end on the compressed air injection port side. The surface treatment apparatus according to claim 1. The surface treatment apparatus according to claim 2, wherein the distance of the second accelerating portion is equal to or greater than the distance of the first accelerating portion. The claim is characterized in that the mechanism for cooling the work piece is a mechanism in which a cooling pipe is stretched inside a processing table on which the work piece is placed and a cooling medium is allowed to flow through the cooling pipe. The surface treatment apparatus according to any one of 1 to 3. The surface treatment method using the surface treatment apparatus according to any one of claims 1 to 4.
The process of heating the compressed air generated by the pressure air source and
A step of injecting the compressed air inside the nozzle body to create a negative pressure in the mixing chamber provided inside the nozzle body.
A step of sucking the injection material into the mixing chamber and mixing it with compressed air through a path from the injection material suction port connected to the tank in which the injection material is stored to the mixing chamber.
Including a step of injecting the mixed compressed air and the injection material as a solid air two-phase flow through a path from the mixing chamber to the injection port.
The compressed air is heated to 100 to 500 ° C.
A surface treatment method characterized by subjecting the surface treatment while cooling the work piece.

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