JP2019081211A - Surface treatment device and surface treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treatment apparatus and a surface treatment method for performing surface treatment such as blasting and shot peening more efficiently than in the past. SOLUTION: 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 a surface treatment chamber is formed inside. The nozzle assembly is a nozzle body having an injection material suction port for sucking the injection material and an ejection port for ejecting the sucked injection material together with compressed air, and an air nozzle whose side is inserted into the nozzle body at least once. The other end includes an air nozzle connected to a compressed air generation source that generates compressed air. A heating mechanism for heating the compressed air is provided in the path between the compressed air generation source and the air nozzle. [Selection diagram] Fig. 1

Description

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

  The surface treatment apparatus carries out surface treatment (blasting, shot peening) of the workpiece by jetting a jet material (shot, grid, abrasive, etc.) from the nozzle assembly toward the workpiece along with the compressed air. The nozzle assembly mounted on the surface treatment apparatus is known as a pressure type and a suction type.

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

  The suction type nozzle assembly is of a type in which the spray material is sucked by the suction force generated by the compressed air flow introduced into the air nozzle, and is jetted together with the compressed air as a solid-gas two-phase flow. (See Patent Document 2.) Since there is no need to seal the container for storing the propellant as in the pressurized type, there is an advantage that the propellant can be jetted continuously. However, since the suction type nozzle assembly sucks the propellant under the atmosphere with the air, there is a pressure loss, which causes a problem that the jetting speed of the propellant is slower than that of the pressurized 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, the need for a more powerful compressed air source leads to an increase in equipment cost and an increase in operating energy of the compressed air source.

JP 02-160514 A Japanese Patent Application Laid-Open No. 08-267360

  The present invention has been made to solve the problems of the prior art described above, and is a surface treatment capable of treating the surface of a workpiece by efficiently spraying a jet material toward the workpiece. An object of the present invention is 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 a surface of a workpiece by causing a propellant mixed with compressed air to collide with a workpiece as a solid-gas two-phase flow. The surface treatment apparatus includes a nozzle assembly for injecting a solid-gas two-phase flow, and a housing in which the nozzle assembly is housed and which forms a surface treatment chamber. The nozzle assembly includes a nozzle body and an air nozzle. The nozzle body includes a jet material suction port for suctioning the jet material, and a jet port for jetting the suctioned jetted material together with the compressed air in a mixing chamber provided inside the nozzle assembly. The air nozzle is inserted at least once into the nozzle body, and is connected to a compressed air source that generates compressed air at the other end. And the heating mechanism for heating compressed air is provided in the supply path of the air from a compressed air generation source to an air nozzle.

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

  By heating the compressed air, the flow velocity of the compressed air is increased. In addition, although the abrasive grains may be coagulated depending on their properties and atmosphere, the adhesion between the particles can be weakened by heating to break up the aggregates. By these synergistic effects, the injection material can be injected efficiently, and the surface treatment capacity can be improved.

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

  In an embodiment of the present invention, the distance of the second acceleration portion may be equal to or greater than the distance of the first acceleration portion. By causing the compressed air passing through the second acceleration unit to flow along the wall surface, acceleration can be efficiently performed.

  One embodiment of the present invention may further comprise a mechanism for cooling the workpiece. Since the influence of the increase in temperature of the workpiece due to the heating of the solid-gas two-phase flow can be suppressed, surface treatment can be widely performed.

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

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 base mounted in the surface treatment apparatus of one Embodiment of this invention. It is a front view which shows the nozzle assembly mounted in the surface treatment apparatus of one Embodiment of this invention. It is a flowchart which shows the surface treatment method of one Embodiment of this invention. It is a schematic diagram which shows the aspect made to move to the workpiece | work in the surface treatment apparatus of one Embodiment of this invention. The cross-sectional shape of the workpiece | work after performing surface treatment by the surface treatment method of one Embodiment of this invention is shown. It is a graph which shows the influence of the temperature of the compressed air in the surface treatment apparatus of one Embodiment of this invention.

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

  FIG. 1: is a front view which fractures | ruptures and shows a part of surface treatment apparatus 01 which concerns on one Embodiment. The surface treatment apparatus 01 is an apparatus for forming a hole in the work W by projecting a jet material onto a work W (workpiece) made of fiber reinforced plastic. As shown in FIG. 1, the surface treatment apparatus 01 includes a housing 10, a quantitative 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. A door 11 is provided on the front of the housing 10, and the operator can access the processing chamber R by opening the door 11. In the processing chamber R, a nozzle fixing jig 12, a processing table 13 and a moving mechanism 14 are provided.

  The nozzle fixing jig 12 is a mechanism for holding the nozzle assembly 60, and can move the nozzle assembly 60 along the height direction. Therefore, the nozzle fixing jig 12 is configured to be able to freely adjust the distance between the nozzle assembly 60 and the work W.

  The moving mechanism 14 is provided on a pedestal 15 provided at the lower part of the housing 10 and disposed below the nozzle assembly 60. In one embodiment, the movement mechanism 14 may be a plate-like body in which a large number of through holes are formed. By forming such a through hole in the moving mechanism 14, the injection material ejected from the nozzle assembly 60 can be allowed to pass toward the bottom of the housing 10.

  A processing table 13 is provided on the moving mechanism 14 and supports the workpiece W placed thereon. The processing table 13 only needs to be capable of mounting the work W, but since the solid-gas two-phase flow is heated as described later, a function for 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, the cooling pipe 13 a is stretched around the inside of the processing table 13, and the work W is cooled by flowing a cooling medium (for example, water) in the cooling pipe.

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

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

  A separating mechanism 30 is provided above the storage hopper 21 of the fixed amount supply mechanism 20. The separation mechanism 30 is connected to the storage hopper 21 of the fixed amount supply mechanism 20. The separating mechanism 30 has a substantially inverted pyramid shape, recovers the used propellant and classifies it into reusable propellant and dust. One end of a first transport pipe P1 is connected to the separation mechanism 30. The other end of the first transport pipe P <b> 1 is connected to the bottom of the housing 10. Therefore, the space in the processing chamber R and the space in the quantitative 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 separating mechanism 30, but any other type of classifier such as a wind type classifier, a screen type classifier, etc. may be used as the separating mechanism 30. Can.

  Further, one end of a 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 applying a negative pressure to the processing chamber R to prevent the injection material from leaking out of the processing chamber R, and for suctioning particles containing the injected injection material. The suction mechanism 40 recovers the light particles (propellant material which is not suitable for reuse, cutting powder of the work W) classified in the separation mechanism 30 (cyclone type classifier) via the second transport pipe P2 Do. In addition, the suction mechanism 40 has a function of making the internal space of the separation mechanism 30 negative pressure 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 portion of the surface treatment apparatus 01. In one embodiment, the control device 50 sends control signals to the moving mechanism 14, the constant amount supplying mechanism 20, the suction mechanism 40, the heating mechanism 70, the solenoid valve VL 1 and the valve VL 2 to operate the moving mechanism 14, the constant amount supplying mechanism 20. , The operation of the suction mechanism 40, the opening and closing of the solenoid valve VL1, and the like. As the control device, various arithmetic devices 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 a jet material onto the workpiece W, and as shown in FIG. 3, includes a nozzle body 61 and an air nozzle 62 for injecting compressed air into the nozzle body 61. ing.

  The nozzle body 61 includes a nozzle holder 61a and a cylindrical injection nozzle 61b which is fitted and fixed from one end side (lower end surface side in FIG. 3) of the nozzle holder 61a. An air nozzle 62 is inserted into and fixed to the other end side (upper end face side in FIG. 3) of the nozzle holder 61 a of the nozzle main body 61. In the vicinity of the lower end of the air nozzle 62 and the upper end of the injection nozzle 61 b inside the nozzle main body 61, a mixing chamber 64 which forms a space inside the nozzle main body 61 is provided.

  A jet material suction port 63 for suctioning the jet material is provided in the upper portion of the nozzle holder 61a, and is connected to the quantitative supply mechanism 20 via a jet 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.

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

  In the nozzle main body 61, the above-described injection material suction port 63, the first path F1, the mixing chamber 64, the second path F2, and the injection port 65 are in communication.

  The air nozzle 62 has a cylindrical shape, in which a third path F3 which is a path of compressed air is formed, and a compressed air injection port 62a is formed at the tip (lower end in FIG. 3) to which compressed air is injected. A compressed air inlet 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 are in communication with each other, and form a second path F2 through which the compressed air flows. The second path F2 in one embodiment includes a compressed air introducing portion 62c having a continuous diameter, a first accelerating portion 62d communicating with the compressed air introducing portion 62c, and gradually reducing the diameter toward the tip, And a second acceleration portion 62e communicating with the first acceleration portion 62d and gradually expanding in diameter toward the compressed air injection port 62a. The compressed air introduction portion 62c, the first acceleration portion 62d, and the second acceleration portion 62e are disposed on the same axial center.

  The compressed air introduction port 62b is connected to a compressed air supply source C via an air pipe H1, and 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 62 a is inserted into and fixed to the nozzle holder 61 a so as to be located in the mixing chamber 64. The compressed air introduced from the compressed air introduction part 62c is compressed and accelerated in the first acceleration part 62d, and then further expanded by being gradually expanded in the second acceleration part 62e, and thus compressed air injection It is injected from the mouth 62a. Since compressed air can be injected at a high speed, the injection speed of the solid-gas two-phase flow injected from the injection port 65 also increases. As a result, since the surface treatment capacity is improved, 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 the compressed air that has passed through the first acceleration portion 62d can be accelerated most efficiently by flowing along the wall surface of the second acceleration portion 62e.

  When the compressed air is injected from the compressed air injection port 62a, the injection flow goes straight while taking in surrounding air, so that the mixing chamber 64 has a negative pressure and a suction force is generated. By the suction force, the jetted material stored in the storage hopper 21 is sucked into the mixing chamber 64 through the first path F1 via the conveyance path 22 and the jetted material hose H2. The injection material that has reached the mixing chamber 64 is mixed with the compressed air, and is injected toward the work W from the injection port 65 as a solid-gas two-phase flow through the second path F2. The propellant is sucked from the propellant 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 injected as a solid-gas two-phase flow. Here, since the suction force changes in size depending on the distance between the compressed air jet port 62a and the inner wall surface of the jet nozzle 61b, the air nozzle 62 is vertically moved to adjust the suction force so as not to be illustrated. It fixes to nozzle holder 61a with a bolt etc. However, if the distance is too short, the flow of the mixed injection material to the injection nozzle 61b is hindered. In the air nozzle 62 of one embodiment, since the compressed air is sufficiently accelerated by the first accelerating portion 62 d and the second accelerating portion 62 e and the injection speed is high, the force for taking in surrounding air is improved. As a result, since the suction force generated in the mixing chamber 64 becomes strong, sufficient suction force for suctioning the jet material can be obtained even if the distance between the compressed air jet port 62a and the wall surface of the mixing chamber 64 is increased. it can. That is, by using the air nozzle 62 according to one embodiment, it is possible to realize the improvement of the injection speed of the solid-gas two-phase flow and the increase of the injection amount of the injection material, so the efficiency of surface treatment can be improved.

  The nozzle assembly 60 having the configuration of one embodiment can continuously eject the injection material, so that the workpiece W can be processed continuously for a long time. If the injection speed of the solid-gas 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 acceleration portion 62e, a flow straightening portion may be provided that communicates with the first acceleration portion 62d and has the same diameter toward the compressed air injection port 62a.

  As the injection material to be injected from the nozzle, metal or non-metal shot or grid or cut wire, ceramic particles (alumina type, silicon carbide type, zircon type, etc.), natural stone particles (emery, silica stone, diamond, etc.) And plant-based particles (eg, hulk shell, peach seed, rattan seed, etc.), resin-based particles (nylon, melamine, urea, etc.) and the like.

  The heating mechanism 70 is connected to the air supply path from the compressed air source C to the air nozzle 62. The heating mechanism 70 may have any configuration as long as it can heat the compressed air to a predetermined temperature. In one embodiment, the heating element is fixed around the tube through which the compressed air can pass.

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

<S1: Preparation of surface treatment apparatus>
In the step (S1) of preparing the surface treatment apparatus 01, (a) set of injection material, (b) adjustment of injection speed of solid-gas two-phase flow, (c) set of work W, (d) nozzle assembly 60 Adjustment of the distance between the workpiece W and the workpiece W, (e) setting of the operating condition of the moving mechanism, (f) setting of the operating condition of the fixed amount supplying mechanism 20, and (g) setting of the heating temperature are performed.

(A) Setting of Injection Material First, the suction mechanism 40 is operated to suction the processing chamber R. Next, the door 11 is unlocked to open the door 11 and, for example, the operator inserts a predetermined amount of the injection material into the processing chamber R. Next, the injection material is transferred to the storage hopper 21 of the fixed amount supply mechanism 20 through the first transport pipe P1 and the separation mechanism 30 by the suction force of the suction mechanism 40. Thereafter, the door 11 is closed and locked. In addition, since the inside of the processing chamber R becomes negative pressure by the suction of the suction mechanism 40, the outside air flows into the processing chamber R from a suction hole (not shown) provided to communicate with the outside.

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

(C) Setting of Workpiece After adjusting the injection speed, the controller 50 is operated to set the solenoid valve VL1 to "close" and the quantitative supply mechanism 20 to "OFF". Such setting stops the injection of the injection material from the nozzle assembly 60. Thereafter, the door 11 is opened, and the work W is placed on the processing table 13 and fixed.

(D) Adjustment of the distance between the nozzle assembly and the work Next to the surface treatment apparatus 01, the nozzle fixing jig 12 is operated to adjust the distance and the angle between the nozzle assembly 60 and the work W . Thereafter, the door 11 is closed and locked.

(E) Setting of Operating Condition of Moving Mechanism The operating condition of the moving mechanism 14 includes the movement locus of the moving mechanism 14 (distance in the X and Y directions in FIG. 5), the moving speed, and the number of scans. The controller 50 is operated to input these conditions.

(F) Setting of Operating Conditions of Fixed-Quantity Supplying Mechanism A fixed amount of injection material is supplied to the nozzle assembly 60 by the fixed-quantity supplying mechanism 20. When the supply amount is large, the surface treatment capacity is improved, but when the supply amount is too large, the injection material stays in the injection material hose H2 or the mixing chamber 64, and the injection material can not be injected gradually. The control device 50 is operated to input the operating conditions of the constant amount supply mechanism so as to obtain an appropriate injection material supply amount.

(G) Setting of heating temperature A thermometer T is disposed 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 controller 50 is operated to input the operating conditions of the quantitative supply mechanism so that the temperature of the compressed air becomes a predetermined temperature. When the temperature of the compressed air is too low, the improvement of the efficiency by heating is small, and when it is too high, the propellant may be denatured (such as softening or surface oxidation). It sets suitably in consideration of these. For example, when using a ceramic-type injection material, it may be selected from the range of 100 to 500 ° C.

<S2: Surface treatment process>
In the surface treatment step (S3) for surface treatment, when the controller 50 is operated, a signal to open the solenoid valve VL1 is first issued, and compressed air is supplied to the nozzle assembly 60. A signal is then issued to activate the heating means "ON". When the temperature of the compressed air rises to a predetermined temperature, a signal to turn on the quantitative supply mechanism 20 is issued, and the spray material is ejected from the nozzle assembly 60. Next, a signal to turn on the moving mechanism 14 is issued, and the moving mechanism 14 operates so as to move the workpiece W in the horizontal direction (the XY direction in FIG. 5). For example, 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 Then, as shown in FIG. 5, the injection area A moves so as to draw a comb-like locus T with respect to the work W. As a result, the injection material collides with the entire surface of the workpiece W substantially uniformly. In one embodiment, this operation may be performed multiple times. The injection port of the nozzle assembly 60 may have a rectangular planar shape. Since the injection area A can be enlarged, the efficiency of the surface treatment of the workpiece 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-gas two-phase flow can be increased as compared to 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 to the conventional surface treatment method. In another aspect, when it is desired to obtain the same solid-gas two-phase injection speed, the surface treatment method according to one embodiment can reduce the flow rate from the compressed air source, so the compressed air source C can be used. It can be miniaturized or the energy for operating the compressed air source C can be low.

  Moreover, in the conventional surface treatment method, it may be sprayed in the state which the injection material aggregated, under the influence of the moisture contained in ambient humidity or compressed air. The surface treatment with the agglomerated injection material leads to the dispersion of the degree of the surface treatment with each workpiece W when the plurality of workpieces W are surface-treated. In the surface treatment method of one embodiment, since the compressed air is heated, moisture in the compressed air is removed. In addition, even if the injection material is supplied to the mixing chamber 64 in a state of aggregation due to the influence of the ambient humidity, the cohesion is weakened by heat, so during mixing with compressed air or in solid-gas two-phase flow This aggregation is broken up. Therefore, according to the surface treatment method of the embodiment, since the collision of the ejection material in the aggregated state can be prevented, the reliability of the surface treatment for the workpiece W is improved.

  By heating the compressed air, the solid-gas two-phase flow is also heated. When there is a concern that the workpiece W may be damaged by the heated solid-gas two-phase flow, a cooling medium may be allowed to flow through the cooling pipe 13 a to perform surface treatment while cooling the workpiece W.

<S3: Recovery process>
In the step (S3) of collecting the workpiece W after the surface treatment, when the operation of the set moving mechanism 14 is finished, the signal for turning off the heating mechanism 70 and turning off the constant amount feeding mechanism 20 is the control device 50 respectively. Power is output, heating is stopped, and injection of the injection material 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 a step provided as appropriate, and may be omitted. When the nozzle assembly 60 is cooled, a signal to close the solenoid valve VL1 is output from the controller 50, and the supply of compressed air to the nozzle assembly 60 is stopped. Thereafter, the door 11 is unlocked to open the door 11 and the work W is removed from the processing table 13. Then, after the jetted material and dust adhering to the workpiece W are removed by air blow or the like, the material is taken out of the processing chamber R, and a series of surface treatments are completed.

  Next, the result of having performed surface treatment by the surface treatment method of one embodiment is explained. In the following description, blasting is selected as the surface treatment, and the result of blasting using a float glass plate as a workpiece W will be described.

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

  The processing cross section of the workpiece W after the blast processing was observed by the surface roughness / contour shape composite measuring machine to measure the processing depth.

  The results are shown in FIG. 6A shows a cross-sectional shape when blasting is performed without heating compressed gas (at room temperature), and FIG. 6B shows a cross-sectional shape when blasting is performed by heating compressed air to 200 ° C. It is. When blasting was performed with compressed air at room temperature, processing was performed to a depth of about 10 μm, whereas when blasting was performed using compressed air heated to 200 ° C., processing was performed 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 influence 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 by a pitot tube. 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 influence of the temperature of the compressed air on the injection speed of the compressed air, the horizontal axis represents the pressure of the compressed air at the time of injection (hereinafter referred to as the injection pressure), and the vertical axis represents 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. 7 (B) shows the rate of increase of the injection speed at each temperature with respect to the case where the temperature of the compressed air is room temperature. As in FIG. 6A, the horizontal axis is the injection pressure, and the vertical axis is the injection speed. At 50 ° C., the rate of increase was lower than 110% for any injection pressure compared to room temperature, and the effect of improving the injection speed by heating was small. Also, it can be seen that the effect of increasing the injection speed is less at 500 ° C. than at 400 ° C.

  Although the blasting was selected and demonstrated as surface treatment in the Example, the surface treatment apparatus and surface treatment method of one embodiment are applicable also to shot peening treatment.

DESCRIPTION OF SYMBOLS 01 surface treatment apparatus 10 housing | casing 20 fixed_quantity_supply mechanism 30 isolation | separation mechanism 40 suction mechanism 50 control apparatus 60 nozzle assembly 70 heating mechanism A injection area | region C compressed air supply source F1-F3 1st-3rd course H1 air piping H2 injection Material hose P1, P2 1st, 2nd transport pipe R Process chamber T Trajectory VL1 Solenoid valve VL2 valve W Work

Claims (5)

A surface treatment apparatus for treating a surface of a workpiece by causing a jet material mixed with compressed air to collide with a workpiece as a solid-gas two-phase flow,
A nozzle assembly for injecting the solid-gas two-phase flow;
A housing in which the nozzle assembly is housed and which forms a surface treatment chamber therein;
Including
The nozzle assembly includes a nozzle main body having a jet material suction port for suctioning a jet material and a jet port for jetting the suctioned jet material together with compressed air in a mixing chamber provided therein, and at least once on the side. An air nozzle inserted into the nozzle body, the air nozzle connected to a compressed air generation source generating compressed air at the other end,
A surface treatment apparatus characterized in that a heating mechanism for heating compressed air is provided in a supply path of air from the compressed air generation source to the air nozzle.   The air nozzle is provided at its tip with a compressed air jet, and a path from the side connected to the compressed air supply source to the compressed air jet is directed to a reduced diameter end located on the compressed air jet side And a second accelerating portion that continuously diameter-expands from the diameter reducing end toward the diameter-expanding end on the compressed air injection port side. The surface treatment apparatus according to claim 1, wherein   The surface treatment apparatus according to claim 2, wherein a distance of the second acceleration unit is equal to or more than a distance of the first acceleration unit.   The surface treatment apparatus according to any one of claims 1 to 3, further comprising a mechanism for cooling the workpiece. A surface treatment method by the surface treatment apparatus according to any one of claims 1 to 4, wherein
Heating the compressed air generated by the pressure air source;
Injecting the compressed air inside the nozzle body to make the mixing chamber provided inside the nozzle body negative pressure;
Sucking the propellant into the mixing chamber through a path from the propellant suction port connected to the tank where the propellant is stored to the mixing chamber and mixing it with compressed air;
Injecting the mixed compressed air and the injection material as a solid-gas two-phase flow through a path from the mixing chamber to the injection port,
The said compressed air heats to 100-500 degreeC, The surface treatment method characterized by the above-mentioned.