Injection method of projection material and injection system of projection material

Abstract

To provide an injection method of a projection material which inhibits increase in an amount of supply of a gas used for injection of a projection material, and to provide an injection system of the projection material.SOLUTION: An injection method of a projection material is an injection method in which the projection material is injected to a workpiece with gas. The injection method comprises: a step in which an injection state of the projection material to the workpiece is acquired; and a step in which supply of the gas is controlled on a basis of the injection state of the projection material and the projection material is injected to the workpiece intermittently.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a method for spraying a projection material and a system for spraying a projection material. [Background technology]

[0002] Conventionally, there has been known an apparatus for performing surface treatment of a workpiece (processing target) by spraying a blasting material onto the workpiece. For example, Patent Document 1 describes a sandblasting apparatus that sprays a mixed fluid of high-pressure gas and an abrasive. This apparatus includes an abrasive spray nozzle that is supplied with high-pressure gas and an abrasive and sprays the abrasive continuously. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-154894 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the sandblasting device described in Patent Document 1, the amount of gas supplied increases according to the injection time, which may increase the power consumption of the gas supply source. The present disclosure provides a method for injection of a projection material and a system for injection of a projection material that suppresses the increase in the amount of gas supplied to be used for injection of the projection material. [Means for solving the problem]

[0005] The method for spraying a blast material according to the present disclosure is a method for spraying a blast material together with a gas toward a workpiece, and includes the following steps (1) and (2). (1) A process for acquiring the state of projection material being sprayed onto a workpiece. (2) A process of controlling the gas supply based on the spraying state of the blast material and intermittently spraying the blast material at the workpiece.

[0006] A projection material injection system according to another aspect of the present disclosure includes an injection device, a measurement device, and a control device. The injection device injects the projection material together with gas toward the workpiece. The measurement device measures the state of injection of the projection material toward the workpiece by the injection device. The control device controls the injection device. The control device has an acquisition unit and an injection control unit. The acquisition unit acquires the state of injection of the projection material toward the workpiece from the measurement device. The injection control unit manages the supply of gas based on the state of injection of the projection material toward the workpiece, and controls the injection device to intermittently eject the projection material toward the workpiece. Effect of the Invention

[0007] According to the present disclosure, it is possible to suppress an increase in the supply amount of gas used to spray projection material. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an injection system according to an embodiment; [Diagram 2] FIG. 2 is a block diagram showing the functional configuration of a projection material ejection system according to an embodiment. [Diagram 3] 5 is a flowchart showing a method for spraying a projection material according to an embodiment. [Figure 4] 1 is a graph showing an example of a relationship between residual stress and depth of a workpiece. [Diagram 5] 1 is a graph showing an example of a relationship between an AE parameter and time. [Figure 6] 1 is a graph showing an example of a relationship between gas pressure and time. [Figure 7] 1 is a graph showing an example of a relationship between a gas flow rate and time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Overview of the embodiment of the present disclosure] First, an overview of the embodiment of the present disclosure will be described.

[0010] (Clause 1) A method for spraying a blast material according to one aspect of the present disclosure is a method for spraying a blast material together with a gas toward a workpiece, and includes the following steps (1) and (2). (1) A process for acquiring the state of projection material being sprayed onto a workpiece. (2) A process of controlling the gas supply based on the spraying state of the blast material and intermittently spraying the blast material at the workpiece.

[0011] In this projection material injection method, the supply of gas is managed based on the injection state of the projection material, and the projection material is intermittently injected together with the gas to the workpiece. This projection material injection method appropriately manages the supply of gas based on the injection state of the projection material, thereby appropriately securing the amount of projection material that contributes to the surface treatment of the workpiece, while reducing the amount of projection material that does not contribute to the surface treatment of the workpiece. As a result, this projection material injection method can appropriately perform surface treatment on the workpiece in the same manner as in the case of continuously injecting the projection material, for example. In addition, by managing the injection state of the projection material, it is possible to monitor whether the surface treatment of the workpiece has been appropriately performed, and the accuracy of the processing of the workpiece can be confirmed. Furthermore, in this projection material injection method, by intermittently injecting the projection material, a time during which the projection material is not injected can be provided compared to the case of continuously injecting the projection material. Therefore, this projection material injection method can suppress an increase in the supply amount of gas used to inject the projection material.

[0012] (Clause 2) In the projection material injection method described in Clause 1, the injection step may include adjusting at least one of the flow rate and pressure of the gas supplied based on the injection state of the projection material, and intermittently injecting the projection material onto the workpiece. In this case, the projection material is injected with an appropriate output based on at least one of the adjusted flow rate and pressure. In this projection material injection method, even if the amount of injection of the projection material is reduced by reducing the amount of gas supplied compared to the case where the projection material is continuously injected, the surface of the workpiece is treated by the projection material injected with an appropriate output. As a result, this projection material injection method can appropriately perform surface treatment on the workpiece in the same manner as, for example, the case where the projection material is continuously injected. In addition, this projection material injection method can appropriately perform surface treatment on the workpiece with a small amount of gas supplied while taking the same time as the case where the projection material is continuously injected.

[0013] (Clause 3) In the method for spraying a projection material according to clause 1 or 2, the acquiring step may further acquire a residual stress value required for the workpiece, and the spraying step may adjust the spray time interval for each spray of the projection material based on the spray state of the projection material and the residual stress value, and spray the projection material intermittently at the workpiece. In this case, the method for spraying a projection material can spray the projection material intermittently at appropriate time intervals, efficiently perform surface treatment on the workpiece, and appropriately obtain a workpiece to which a residual stress corresponding to the required residual stress value has been imparted.

[0014] (Clause 4) In the method for spraying a projection material according to clause 1 or 2, the acquiring step may further acquire surface information related to a surface state required for the workpiece, and the spraying step may adjust the spray time interval for each spray of the projection material based on the spray state and surface information of the projection material, and spray the projection material intermittently at the workpiece. In this case, the method for spraying a projection material can spray the projection material intermittently at appropriate time intervals, efficiently perform surface treatment on the workpiece, and appropriately obtain a workpiece corresponding to the required surface state.

[0015] (Clause 5) A projection material injection system according to another aspect of the present disclosure includes an injection device, a measurement device, and a control device. The injection device injects the projection material together with gas toward a workpiece. The measurement device measures the injection state of the projection material toward the workpiece by the injection device. The control device controls the injection device. The control device has an acquisition unit and an injection control unit. The acquisition unit acquires the injection state of the projection material from the measurement device. The injection control unit manages the supply of gas based on the injection state of the projection material, and controls the injection device to intermittently inject the projection material toward the workpiece. This projection material injection system achieves the same effects as the projection material injection method described in clause 1.

[0016] [Examples of the embodiments of the present disclosure] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same or equivalent elements are denoted by the same reference numerals, and redundant description will not be repeated. The dimensional ratios of the drawings do not necessarily correspond to those in the description.

[0017] [Outline of the injection system] FIG. 1 is a diagram showing a schematic diagram of a projection material injection system according to one embodiment. The projection material S injection system 1 shown in FIG. 1 (hereinafter, may be simply referred to as "injection system 1") injects (projects) the projection material together with gas onto a workpiece W (processing target) in order to process the workpiece. In this embodiment, the process of injecting the projection material S in the injection system 1 is referred to as "injection process". The injection process includes shot blasting for the purpose of removing scale, removing burrs, adjusting surface roughness, and the like, and shot peening for the purpose of imparting residual compressive stress to the workpiece. As an example, the injection process in this embodiment refers to shot peening process.

[0018] As shown in FIG. 1, the injection system 1 includes an injection device 10, a measurement device 20 (sensing unit), and a control device 30. The injection device 10 injects a blast material S together with a gas onto the workpiece W. The injection device 10 processes the surface of the workpiece W by injecting the blast material S onto the workpiece W and colliding the blast material S with the workpiece W. For example, the injection device 10 is a shot peening device that imparts compressive residual stress to the surface of the workpiece W. Examples of the workpiece W that is subjected to the injection treatment by the injection device 10 include automobile parts such as cylinder heads and crankshafts, gears, dies, etc., but the workpiece W is not limited to these. The injection treatment imparts compressive residual stress to the surface of the workpiece W, thereby improving the fatigue properties of the workpiece W.

[0019] The injector 10 is a gravity type (suction type) shot peening device. The injector 10 may be a direct pressure type shot peening device. As the shot material S to be blasted onto the workpiece W, for example, steel balls are used. The particle size of the steel balls is appropriately selected according to the compressive residual stress required (to be imparted) to the workpiece W.

[0020] The spray device 10 includes a shot material tank 11, a compressor 12, and a nozzle 15. The shot material tank 11 stores shot material S. The shot material tank 11 is connected to the nozzle 15 via a pipe 60. The shot material tank 11 is provided with an outlet 11A through which the shot material S flows out. The outlet 11A is provided with a cut gate 61 that can be opened and closed. The outlet 11A is connected to a pipe 60 via the cut gate 61. The pipe 60 may be provided with an adjustment valve that adjusts the amount of shot material S sprayed from the nozzle 15.

[0021] The compressor 12 generates compressed gas (compressed air) and supplies the compressed gas to the nozzle 15. The compressor 12 is connected to the nozzle 15 via a pipe 62. An air filter 63 is provided in the pipe 62 at a position between the compressor 12 and the nozzle 15. The air filter 63 removes dust from the compressed gas supplied from the compressor 12 to the nozzle 15. A regulator 64 is provided in the pipe 62 at a position between the air filter 63 and the nozzle 15. The regulator 64 is a valve that reduces the pressure of the compressed gas supplied from the compressor 12 to the nozzle 15 to a predetermined level.

[0022] A first pressure sensor 65 is provided in the piping 62 between the regulator 64 and the nozzle 15. The first pressure sensor 65 measures the pressure of the compressed gas whose pressure has been adjusted by the regulator 64. A solenoid valve 66 is provided in the piping 62 between the first pressure sensor 65 and the nozzle 15. The solenoid valve 66 controls the passage or non-passage of the compressed gas supplied from the compressor 12 to the nozzle 15. A flow rate sensor 67 is provided in the piping 62 between the solenoid valve 66 and the nozzle 15. The flow rate sensor 67 measures the flow rate of the compressed gas supplied from the compressor 12 to the nozzle 15. A second pressure sensor 68 is provided in the piping 62 between the flow rate sensor 67 and the nozzle 15. The second pressure sensor 68 measures the pressure of the compressed gas after passing through the solenoid valve 66 (flow rate sensor 67).

[0023] The injection device 10 has an intermittent injection unit 69 at a position between the second pressure sensor 68 and the nozzle 15 in the piping 62. The intermittent injection unit 69 is provided upstream (on the compressor 12 side) of a mixing section 15A described below. The intermittent injection unit 69 intermittently injects compressed gas supplied from the compressor 12. The intermittent injection unit 69 is electrically or mechanically controlled. The intermittent injection unit 69 of this embodiment has, for example, an electrically controlled valve. The intermittent injection unit 69 adjusts the flow rate of the compressed gas supplied to the nozzle 15 to a predetermined flow rate.

[0024] In this manner, the first pressure sensor 65, the flow rate sensor 67, and the second pressure sensor 68 are provided on the upstream side (compressor 12 side) of the nozzle 15 (mixing section 15A described below) in the piping 62. The flow rate sensor 67 is provided in a portion of the piping 62 close to the original pressure of the gas whose pressure has been adjusted, and is provided in the vicinity of the regulator 64. The intermittent injection unit 69 is provided, for example, on the upstream side (compressor 12 side) of the piping 62 just before the nozzle 15 (mixing section 15A described below). The order of the components in the piping 62 is not limited to this.

[0025] The cut gate 61, regulator 64, first pressure sensor 65, solenoid valve 66, flow rate sensor 67, second pressure sensor 68 and intermittent injection unit 69 in the injection system 1 are communicatively connected to the control device 30. The flow rate sensor 67 converts the measured flow rate into digital data and outputs it to the control device 30. The first pressure sensor 65 and the second pressure sensor 68 convert the measured pressure into digital data and output it to the control device 30.

[0026] The nozzle 15 is provided at the tip of the pipes 60 and 62, and sprays the shot material S supplied from the shot material tank 11 together with the compressed gas as a two-phase solid-gas flow. The inside of the nozzle 15 is configured as a mixing section 15A in which the shot material S supplied from the shot material tank 11 and the compressed gas supplied from the compressor 12 are mixed by connecting the pipes 60 and 62 to the nozzle 15.

[0027] The nozzle 15 is disposed inside the cabinet 70. The cabinet 70 defines a processing chamber 70s, which is a space for processing the workpiece W. The workpiece W is disposed on a mounting table 71 in the processing chamber 70s. When performing a blast process on the workpiece W, the workpiece W is disposed in the processing chamber 70s, and the projection material S is projected from the nozzle 15 toward the workpiece in the processing chamber 70s, so that the projection material S collides with the workpiece W.

[0028] Although not shown in Fig. 1, the spraying device 10 may further include a dust collector, a classifier, and a circulation device to reuse the used blast material S. The dust collector is connected to the processing chamber 70s via the classifier, and transports the blast material S and cutting chips of the workpiece W that have fallen to the bottom of the processing chamber 70s to the classifier by sucking them in. The classifier is, for example, a cyclone-type classifier, and receives the blast material S and cutting chips of the workpiece, and classifies them into granules that can be reused as blast material S and granules that cannot be used as blast material S. The circulation device returns the reusable blast material S to the blast material tank 11 via a packet elevator, a screw conveyor, a separator, etc.

[0029] The measuring device 20 detects the ejection state of the projection material S in the ejection device 10. FIG. 2 is a block diagram showing the functional configuration of a projection material ejection system according to an embodiment. As shown in FIGS. 1 and 2, the measuring device 20 includes a sensor 21, an AD conversion unit 22, and a communication unit 23. The sensor 21 acquires a feature quantity indicating the ejection state of the projection material S. The sensor 21 in this embodiment is, for example, an AE sensor. The sensor 21 is fixed to the nozzle 15, measures acoustic emission (AE) generated when the projection material S is ejected from the nozzle 15 of the ejection device 10, and outputs a signal waveform related to the measured AE (hereinafter referred to as the "AE signal waveform"). The AE signal waveform is a signal waveform related to elastic waves such as vibrations or sound waves generated when the projection material S passes (ejects) through the nozzle 15. The AE signal waveform includes, for example, amplitude, duration, AE count, rise time, AE count rate, and average frequency as characteristic parameters related to the intensity of the ejection process.

[0030] The AD conversion unit 22 converts the AE signal waveform output from the sensor 21 into digital data and outputs the digital data. The communication unit 23 is a communication module capable of wireless communication such as LAN, Bluetooth (registered trademark), and Wifi. The communication unit 23 acquires digital data (hereinafter referred to as signal data) of the AE signal waveform measured by the sensor 21 from the AD conversion unit 22, and transmits the signal data to the control device 30 by wireless communication. The first pressure sensor 65, the flow rate sensor 67, and the second pressure sensor 68 may each include an AD conversion unit and a communication unit similar to the AD conversion unit 22 and the communication unit 23 included in the measurement device 20.

[0031] The control device 30 controls the entire injection system 1 for the projection material S. As an example, the control device 30 is configured as a PLC (Programmable Logic Controller). The control device 30 may be configured as a normal computer system including a CPU (Central Processing Unit), a main storage device such as a RAM (Random Access Memory) and a ROM (Read Only Memory), an input device such as a touch panel or a keyboard, an output device such as a display, an auxiliary storage device such as a hard disk, and the like.

[0032] The control device 30 is provided with, for example, an operation panel that can be operated by an operator. The control device 30 is connected to the injector 10 and the measuring device 20 so as to be able to communicate with them. The control device 30 outputs control signals to the injector 10 and the measuring device 20 and controls the operation of each component. The control device 30 reads a program prepared in advance and operates the injector 10 and the measuring device 20. The control device 30 may operate the injector 10 and the measuring device 20 in response to a command operation of an operator received by an operation panel (not shown). In the control device 30, an operator can use an input device to input commands to manage the injector 10. The control device 30 visualizes and displays the operating status of the injector 10 by an output device.

[0033] In the injection system 1, for example, in order to manage the injection device 10 so that the injection material S can be appropriately intermittently injected onto the workpiece W (so that the workpiece W can be appropriately given a residual stress corresponding to a required stress value described later), an injection process is performed before processing the workpiece W, and at least one of the AE parameters, flow rate, and pressure is measured. The control device 30 of this embodiment periodically manages (adjusts) the injection conditions based on the AE parameters. The injection conditions are output conditions set in the injection device 10 to inject the injection material S, and include, for example, gas supply conditions. The injection conditions include, for example, the flow rate and pressure of the gas supplied to the nozzle 15, as well as the injection time and injection time interval of the injection material S. The management is performed once or multiple times, for example, before the injection process is performed onto the workpiece W. The control device 30 controls the injection device 10 so that the injection material S is injected under the managed (adjusted) injection conditions. The control device 30 is communicably connected to the intermittent injection unit 69 in the injection device 10, and outputs a control signal so that gas is intermittently supplied to the nozzle 15 in response to a program or command operation. The details will be explained below.

[0034] 2, the control device 30 includes, as functional components, an acquisition unit 31, an ejection control unit 32, and a memory unit 35. The acquisition unit 31 acquires the ejection state of the projection material S by the ejection device 10 from the measurement device 20. The acquisition unit 31 acquires signal data transmitted from the communication unit 23 of the measurement device 20 as an example of the ejection state of the projection material S by the ejection device 10. Furthermore, the acquisition unit 31 acquires the flow rate of the gas measured by the flow sensor 67, and acquires the pressure of the gas measured by at least one of the first pressure sensor 65 and the second pressure sensor 68.

[0035] The acquisition unit 31 acquires the processing conditions for the workpiece W to be sprayed with the blast material S in the spray device 10. The acquisition unit 31 may acquire, for example, processing conditions input by an operator of the spray device 10, or may acquire processing conditions previously stored in the storage unit 35. As described above, the blast material S sprayed from the nozzle 15 of the spray device 10 collides with the workpiece W. When the blast material S collides with the surface of the workpiece W, a force that strikes and stretches the workpiece W acts on the surface, and a reaction force that opposes the force is generated in the workpiece W, and as a result, a residual stress (compressive residual stress) is imparted to the workpiece W. Here, the residual stress to be imparted to the workpiece W is determined according to the application of the workpiece W. In order to impart the required residual stress to the workpiece W, it is required to perform a spray process with an appropriate strength on the workpiece W at an appropriate time interval. The acquisition unit 31 acquires, as a processing condition, a required stress value (an example of a residual stress value) that is a residual stress required for the workpiece W to be sprayed with the blast material S in the spray device 10. The required stress value is, for example, an integral value in the residual stress distribution indicated by the residual stress and depth, a surface residual stress, and a peak value and / or a peak depth of the compressive residual stress. The acquisition unit 31 may acquire the injection time of the projection material S described below, the injection time interval of the projection material S described below, and information on the projection material S (particle size, hardness, etc.) as processing conditions. Hereinafter, the case where the projection material S is intermittently injected onto the workpiece W at a predetermined gas flow rate and pressure in order to obtain the required stress value in the workpiece W is expressed as "intermittent injection". Also, below, the case where the projection material S is continuously injected onto the workpiece W at a predetermined gas flow rate and pressure in order to obtain the required stress value in the workpiece W is expressed as "continuous injection".

[0036] The injection control unit 32 manages the supply of gas based on the injection state of the projection material S, and controls the injection device 10 to intermittently inject the projection material S onto the workpiece W. The injection control unit 32 has a management unit 33 and an intermittent injection control unit 34. The management unit 33 manages the supply of gas based on the injection state of the projection material S onto the workpiece W. The management of the gas supply includes setting and adjusting at least one of the flow rate and pressure of the gas supplied by the injection control unit 32 after the measurement device 20 detects a characteristic amount related to the gas supply including at least one of the AE parameter, flow rate, and pressure. The management of the gas supply also includes controlling the injection control unit 32 to supply the gas at the flow rate and pressure before detection after the measurement device 20 detects the above-mentioned characteristic amount. The management of the gas supply may include predicting and determining whether or not appropriate injection is being performed in the injection device 10 after the measurement device 20 detects the above-mentioned characteristic amount. The management unit 33 of this embodiment manages the flow rate and pressure of the gas to obtain a required stress value in the workpiece W based on the AE parameters indicated as the spray state of the projection material S and the processing conditions of the workpiece W.

[0037] The management unit 33 calculates the AE parameters from the AE signal waveform included in the signal data acquired by the acquisition unit 31. For example, the amplitude, duration, AE count, or rise time of the AE signal waveform is used as the AE parameter. The peak value, average value, or effective value of the AE signal waveform may be used as the AE parameter. There is a correlation between the AE parameter and the value of the residual stress of the workpiece W. For this reason, for example, a model formula representing the correlation between the AE parameter and the value of the residual stress is stored in advance in the storage unit 35 of the control device 30. The management unit 33 calculates the required AE parameter, which is the AE parameter corresponding to the required stress value acquired by the acquisition unit 31, using, for example, the model formula. The required AE parameter may be calculated by various other methods without being limited to the above-mentioned model formula. For example, the required AE parameter may be calculated based on a data table or the like showing the relationship between the AE parameter and the value of the residual stress of the workpiece W.

[0038] The management unit 33 calculates the flow rate and pressure of the gas to be supplied to the nozzle 15 based on the AE parameters calculated from the signal data acquired by the acquisition unit 31 and the required AE parameters. The management unit 33 acquires a data table indicating the relationship between the AE parameters and the flow rate of the gas to be supplied, and a data table indicating the relationship between the AE parameters and the pressure of the gas to be supplied, both of which are stored in advance in the storage unit 35. The management unit 33 uses these data tables to extract the flow rate and pressure of the gas corresponding to the required AE parameters.

[0039] The management unit 33 calculates the difference between the gas flow rate at the time of acquiring the signal data and the gas flow rate corresponding to the required AE parameter, and determines the flow rate value to be adjusted (increased or decreased) from the flow rate at the time of calculating the measured AE parameter. As an example of the gas flow rate corresponding to the required AE parameter, the management unit 33 assigns the maximum value of the gas flow rate during intermittent injection, which can obtain the required AE parameter (required stress value), to the maximum value of the flow rate during intermittent injection.

[0040] The management unit 33 calculates the difference between the gas pressure at the time of acquiring signal data from at least one of the first pressure sensor 65 and the second pressure sensor 68 and the gas pressure corresponding to the required AE parameter, and determines the value of the pressure to be adjusted (increased or decreased). As an example of the gas pressure corresponding to the required AE parameter, the management unit 33 assigns, for example, the maximum value of the gas pressure during continuous injection at which the required AE parameter (required stress value) can be obtained to the minimum value of the pressure during surface treatment of the workpiece W by intermittent injection. The minimum value of the pressure is the minimum value from the start of the process of imparting residual stress to the workpiece W and the start of intermittent gas supply to the end of the intermittent gas supply.

[0041] The management unit 33 does not have to calculate the flow rate and pressure values ​​to be adjusted. The management unit 33 may, for example, determine the value of the flow rate to be adjusted, thereby determining the corresponding pressure value. The management unit 33 may, for example, determine the value of the pressure to be adjusted, thereby determining the corresponding flow rate value. The management unit 33 may also determine the flow rate and pressure values ​​to be adjusted directly from the difference between the AE parameter and the required AE parameter. The management unit 33 stores the calculated gas flow rate and pressure in the memory unit 35.

[0042] The management unit 33 also sets the injection time of the projection material S until a predetermined residual stress is imparted to the workpiece W, and the injection time interval of the projection material S. The injection time of the projection material S may be the gas supply time. The management unit 33 sets, for example, the time required for continuous injection as the injection time for intermittent injection. The injection time interval of the projection material S may be the gas supply time interval. When the injection device 10 intermittently injects the projection material S, the injection device 10 repeats the operation of starting and stopping the gas supply to the nozzle 15 multiple times within the injection time of the projection material S. The injection time interval of the projection material S refers to the injection time for each injection of the projection material S, and specifically refers to the time from the start of the gas supply to the stop of the gas supply for each injection. The injection time interval is, for example, 0.5 seconds. Within the injection time of the projection material S, the injection time interval of the projection material S may be constant, or may be different for each injection of the projection material S. When the injection device 10 intermittently injects the projection material S, the injection time interval of the projection material S required to impart the same residual stress to the workpiece W as that during continuous injection is determined in advance in correspondence with at least one of the AE parameters, flow rate, and pressure. The injection time interval may be determined in advance in correspondence with each required stress value required for the workpiece W. The management unit 33 acquires, for example, a data table that indicates the relationship between the flow rate or pressure of the supplied gas and the injection time interval of the projection material S, which is stored in advance in the storage unit 35. The management unit 33 uses, for example, the data table to set an injection time interval that corresponds to the calculated flow rate or pressure of the gas.

[0043] The intermittent injection control unit 34 controls the injection device 10 to intermittently inject the projection material S onto the workpiece W based on the injection conditions managed by the management unit 33. The intermittent injection control unit 34, for example, controls the valve in the intermittent injection unit 69 so that gas at a flow rate calculated in the management unit 33 is supplied to the nozzle 15. The intermittent injection control unit 34 controls the regulator 64 so that gas at a pressure calculated in the management unit 33 is supplied to the nozzle 15. The intermittent injection control unit 34, for example, acquires the pressure of compressed gas generated from the compressor 12, and reduces the pressure of the gas to the pressure calculated in the management unit 33. The intermittent injection control unit 34 adjusts the degree of opening of the valve in the intermittent injection unit 69 during the injection time, and opens and closes the valve, so that the injection time interval is set in the management unit 33. The intermittent injection control unit 34 adjusts the degree of opening of the valve in the intermittent injection unit 69 set in the management unit 33, and opens and closes the valve.

[0044] [Projection material injection method] Next, a method for spraying the projection material S onto the workpiece W using the above-mentioned spray system 1 will be described. Fig. 3 is a flowchart showing a method for spraying the projection material according to one embodiment. The method for spraying the projection material S is executed, for example, when the spraying device 10 sprays the projection material S onto the workpiece W for a predetermined spraying time on a trial basis. In this flowchart, the execution time (spraying time) of the method for spraying the projection material S by the spraying device 10 is determined in advance.

[0045] In this method, first, the acquisition unit 31 of the control device 30 acquires the spraying state of the projection material S from the measurement device 20 (Step S1: an example of an acquisition step). The acquisition unit 31 acquires AE parameters from the measurement device 20. Furthermore, the acquisition unit 31 acquires the gas flow rate measured by the flow sensor 67, and acquires the gas pressure measured by at least one of the first pressure sensor 65 and the second pressure sensor 68.

[0046] Next, the injection control unit 32 manages the supply of gas based on the injection state of the projection material S, and controls the injection device to intermittently inject the projection material S at the workpiece W (Step S3: an example of a injection process). The management unit 33 calculates the flow rate and pressure of the gas supplied to the nozzle 15, and the injection time interval of the projection material S, based on the AE parameters indicating the injection state of the projection material S and the required AE parameters. The intermittent injection control unit 34 adjusts the regulator 64 and the intermittent injection unit 69 to achieve the flow rate and pressure, and the injection time interval of the projection material S.

[0047] Next, the intermittent injection control unit 34 determines whether or not a predetermined injection time has elapsed (step S5). If the intermittent injection control unit 34 determines that the predetermined injection time has not elapsed, the process returns to step S1, and adjusts the injection conditions of the projection material S. If the intermittent injection control unit 34 determines that the predetermined injection time has elapsed, the process ends the series of processes of this injection method.

[0048] [Summary of the embodiment] In the injection system 1 and the injection method of the projection material S of this embodiment, the supply of gas is managed based on the injection state of the projection material S, and the projection material S is intermittently injected together with the gas to the workpiece W. This injection method of the projection material S can appropriately manage the supply of gas based on the injection state of the projection material S, thereby appropriately securing the amount of the projection material S that contributes to the surface treatment of the workpiece W, while reducing the amount of the projection material S that does not contribute to the surface treatment of the workpiece W. As a result, this injection method of the projection material S can appropriately perform the surface treatment of the workpiece W in the same manner as in the case of continuous injection. In addition, by managing the injection state of the projection material S, it is possible to monitor whether the surface treatment of the workpiece W has been appropriately performed, and the accuracy of the processing of the workpiece W can be confirmed. Furthermore, this injection method of the projection material S can provide a time during which the projection material S is not injected by intermittent injection, compared to the case of continuous injection. Therefore, this injection method of the projection material S can suppress an increase in the supply amount of gas used to inject the projection material S. This makes it possible to suppress an increase in the amount of power used to supply compressed gas in the compressor 12, and also makes it possible to realize a reduction in the size of the compressor 12.

[0049] In the spraying step (step S3), at least one of the flow rate and pressure of the gas supplied is adjusted based on the spraying state of the projection material S, and the projection material is intermittently sprayed onto the workpiece W. In this case, the method of spraying the projection material S sprays the projection material S with an appropriate output based on at least one of the adjusted flow rate and pressure. In this method of spraying the projection material S, even if the amount of gas supplied is reduced to reduce the amount of projection material S sprayed compared to the case of continuously spraying the projection material S, the surface of the workpiece W is treated by the projection material S sprayed with an appropriate output. As a result, this method of spraying the projection material S can appropriately perform surface treatment on the workpiece W in the same manner as in the case of continuous spraying. For example, the method of spraying the projection material S can appropriately perform surface treatment on the workpiece W with a small amount of gas supplied while requiring the same amount of time as in the case of continuous spraying. Specifically, by intermittently injecting the projection material S within the same time as the time for continuously injecting the projection material S, the flow rate (total amount) of the gas supplied to the nozzle 15 can be suppressed to 20% or more and less than 100% of the flow rate (total amount) of the gas supplied continuously. In the injection method of the projection material S using the injection system 1 of this embodiment, the injection conditions (flow rate and pressure of the gas supplied, etc.) in the intermittent injection can be made to correspond to, for example, the difference between the total amount of the gas during continuous injection and the total amount of the gas during intermittent injection. In addition, the injection conditions in the intermittent injection can be made to correspond to, for example, the ratio of the integral value of the residual stress distribution of the workpiece W during intermittent injection to the integral value of the residual stress distribution of the workpiece W during continuous injection. Therefore, in the injection method of the projection material S using the injection system 1 of this embodiment, by selecting a predetermined injection condition, it is possible to obtain a workpiece W having the same residual stress as that during continuous injection, even during intermittent injection, and the total amount of the gas supplied to the nozzle 15 can also be reduced.

[0050] The acquiring step (step S1) further acquires the residual stress value required for the workpiece, and the spraying step (step S3) adjusts the spraying time interval for each spray of the projection material S based on the spraying state and the residual stress value of the projection material S, and intermittently sprays the projection material S onto the workpiece W. In this case, the spraying method of the projection material S can intermittently spray the projection material S at appropriate time intervals, efficiently perform surface treatment on the workpiece W, and appropriately obtain the workpiece W to which residual stress corresponding to the required residual stress value has been imparted.

[0051] [Variations] The above describes the projection material ejection system and projection material ejection method according to various embodiments, but the present invention is not limited to the above-described embodiments and various modifications can be made without departing from the spirit of the invention.

[0052] In the above embodiment, an AE sensor is used as the sensor 21 of the measuring device 20 to measure elastic waves when the projection material S passes through the nozzle 15, but the measuring device 20 may measure wave motion other than elastic waves and output a signal waveform related to the wave motion. Examples of sensors that measure wave motion other than elastic waves include vibration sensors, acceleration sensors, and impact sensors that measure vibrations, ultrasonic sensors that measure ultrasonic waves, electromagnetic sensors that measure electromagnetism, eddy current sensors, laser displacement meters, and ultrasonic sensors that measure displacement, and color sensors that measure color.

[0053] When an AE sensor is used as the sensor 21, the measuring device 20 does not have to be provided in the nozzle 15. The measuring device 20 may be provided in the vicinity of the workpiece W, for example, on the mounting table 71 for the workpiece W. The measuring device 20 outputs a signal related to a wave motion generated by the collision of the projection material S projected from the spraying device 10 onto the workpiece W. The wave motion is a general term for waves generated when the projection material S collides with the workpiece W, and is a concept that includes elastic waves, vibrations, ultrasonic waves, and electromagnetic waves.

[0054] The sensor 21 of the measuring device 20 does not have to be provided in the configuration around the nozzle 15 and the workpiece W. The sensor 21 of the measuring device 20 may be replaced by a flow sensor 67. At this time, the management unit 33 manages the supply of gas based on the flow rate of the gas as the injection state of the projection material S to the workpiece W. A model formula expressing the correlation between the flow rate of the gas supplied to the nozzle 15 and the value of the residual stress is stored in advance in the memory unit 35 of the control device 30. The management unit 33 calculates the required flow rate, which is the flow rate corresponding to the required stress value acquired by the acquisition unit 31, using the model formula. The management unit 33 calculates the flow rate and pressure of the gas to be adjusted based on the flow rate measured by the flow sensor 67 acquired by the acquisition unit 31 and the required flow rate. The management unit 33 acquires a data table indicating the relationship between the flow rate and the pressure of the gas stored in advance in the memory unit 35. The management unit 33 uses the data table to extract the pressure of the gas corresponding to the required flow rate. The management unit 33 calculates the flow rate and pressure of the gas to be adjusted in the same manner as in the above-mentioned embodiment.

[0055] The sensor 21 of the measuring device 20 may be the first pressure sensor 65 or the second pressure sensor 68. At this time, the management unit 33 manages the supply of gas based on the pressure of the gas as the injection state of the projection material S to the workpiece W. A model formula expressing the correlation between the pressure of the gas supplied to the nozzle 15 and the value of the residual stress is stored in advance in the memory unit 35 of the control device 30. The management unit 33 uses the model formula to calculate the required pressure, which is the pressure corresponding to the required stress value acquired by the acquisition unit 31. The management unit 33 calculates the flow rate and pressure of the gas to be adjusted based on the pressure measured by the first pressure sensor 65 or the second pressure sensor 68 acquired by the acquisition unit 31 and the required pressure. The management unit 33 acquires a data table indicating the relationship between the flow rate and pressure of the gas stored in advance in the memory unit 35. The management unit 33 uses the data table to extract the flow rate of the gas corresponding to the required pressure. The management unit 33 calculates the flow rate and pressure of the gas to be adjusted in the same manner as in the above-mentioned embodiment.

[0056] As described above, the management unit 33 manages the supply of gas based on sensing data such as AE parameters indicating the spray state of the projection material S on the workpiece W, the gas flow rate, and the gas pressure. The management unit 33 regards at least one type of data among the above-mentioned sensing data and the processing conditions as data indicating the spray state of the projection material S on the workpiece W, and manages the supply of gas based on the data. The processing conditions may include initial settings related to the supply of gas and projection material S in the spray device 10, in addition to the spray time of the projection material S, the spray time interval of the projection material S described below, and information related to the projection material S (particle size, hardness, etc.).

[0057] The injection system may perform shot blasting as the injection process. In this case, the injection device is, for example, a blasting device. The acquisition unit of the injection system acquires the injection state of the projection material against the workpiece in the acquisition process, similar to the injection device 10. The acquisition unit of the injection system further acquires surface information related to the surface state required for the workpiece as a processing condition in the acquisition process. The surface information is information related to the processing state of the workpiece to be processed. The surface information includes, for example, information related to surface roughness, surface processing, shape, etc. The information related to surface roughness includes, for example, Ra (arithmetic mean roughness), Pz (maximum height), RzJIS (ten-point mean roughness), etc., as specified in JIS B0601:2013. The information related to surface processing includes the rust degree indicating the degree of adhesion of mill scale or the degree of rust generation, and the rust removal degree indicating the degree of removal of dirt or deposits such as mill scale (black skin), rust, salts, oil, etc. The shape-related information includes, for example, the R value and tolerance indicating the roundness of the corners of the workpiece W when rounding, and the height and base thickness of the burr when removing the burr.

[0058] In the injection process in the injection device, which is a blast processing device, the supply of gas is managed based on the injection state of the projection material, and the projection material is intermittently injected at the workpiece, similar to the injection process (step S3) of the injection device 10. In this injection process, at least one of the flow rate and pressure of the gas supplied is adjusted based on the injection state of the projection material, and the projection material is intermittently injected at the workpiece, similar to the injection process (step S3) of the injection device 10. In this injection process, the injection time interval for each injection of the projection material is adjusted based on the injection state and surface information of the projection material, and the projection material is intermittently injected at the workpiece, similar to the injection process (step S3) of the injection device 10.

[0059] There is a correlation between the sensing data, such as the AE parameters indicating the injection state of the projection material, the flow rate of the gas, and the pressure of the gas, and the surface information of the workpiece. For this reason, for example, a model formula expressing the correlation between the sensing data and the surface information is stored in advance in the storage unit of the control device. The management unit, for example, uses the model formula to calculate a required value, which is the value of the sensing data corresponding to the surface information acquired by the acquisition unit. Note that the required value may be calculated by various other methods without being limited to the above-mentioned model formula. For example, the required value may be calculated based on a data table or the like indicating the relationship between the sensing data and the surface information. The management unit calculates the flow rate and pressure of the gas supplied to the nozzle 15 based on the sensing data and the required value. The management unit calculates the flow rate and pressure of the gas using a method similar to that of the management unit 33 described above. In this case, this injection method of the projection material can intermittently inject the projection material at appropriate time intervals, efficiently perform surface treatment on the workpiece, and appropriately obtain a workpiece corresponding to the required surface state. EXAMPLES

[0060] In the following, in order to explain the above-mentioned effects, the present disclosure will be described in more detail with reference to examples. The present disclosure is not limited to these examples. In the following examples, the spraying method shown in FIG. 3 is carried out under predetermined processing conditions, and the relationship between the residual stress value and the spraying state of the projection material S is compared between the case where the projection material S is sprayed continuously and the case where the projection material S is sprayed intermittently.

[0061] A gravity-type air blasting facility was used as the injection system of the embodiment. Two types of shot materials, 0.3 mm and 0.6 mm in particle size, were used, both of which were made of conditioned cut wire and had a Vickers hardness of 500 HV. A spring steel material SUP9 was used as the workpiece, which was adjusted to have a Vickers hardness of 450 HV. In the continuous injection test, gas was supplied to the nozzle of the injection device at a flow rate of about 600 L / min and a pressure of about 0.34 MPa. The pressure was the pressure of the gas in the vicinity of the nozzle. In the intermittent injection test, the gas flow rate was changed over time to inject the shot material intermittently so that the amount of gas injected was 20% to 60% of the total amount of gas injected when the shot material was continuously injected, and the maximum value of the gas flow rate during one injection was about 600 L / min. The injection time interval of the gas during intermittent injection was about 0.5 seconds.

[0062] FIG. 4 is a graph showing an example of the relationship between the residual stress and depth of a workpiece. The vertical axis of FIG. 4 indicates the residual stress (L / min), and the horizontal axis indicates the depth (μm). The result of continuous injection shown by the dashed line and the result of indirect injection shown by the solid line show almost the same residual stress distribution, regardless of the particle size of the projection material. In this way, the projection material can be injected so that the residual stress distribution of the workpiece after intermittent injection is the same as the residual stress distribution of the workpiece after continuous injection. In the following examples, the results of using a projection material with a particle size of 0.6 mm and spraying so that the residual stress distribution of the workpiece after intermittent injection is the same as the residual stress distribution of the workpiece after continuous injection are shown.

[0063] FIG. 5 is a graph showing an example of the relationship between the AE parameter and time. The vertical axis of FIG. 5 indicates the AE parameter, and the horizontal axis indicates the time (seconds). FIG. 6 is a graph showing an example of the relationship between the pressure of the gas and time. The vertical axis of FIG. 6 indicates the pressure (MPa), and the horizontal axis indicates the time (seconds). FIG. 7 is a graph showing an example of the relationship between the flow rate of the gas and time. The vertical axis of FIG. 7 indicates the flow rate (L / min), and the horizontal axis indicates the time (seconds). The broken lines shown in FIG. 5 to FIG. 7 are the results of continuous injection, and the flow of the gas started about 3.5 seconds after the start of the test. The solid lines shown in FIG. 5 to FIG. 7 are the results of intermittent injection, and the flow of the gas started about 3 seconds after the start of the test. The numerical value of the AE parameter in FIG. 5 changes significantly about 6 seconds after the start of the test, but the numerical value of the pressure in FIG. 6 and the flow rate in FIG. 7 change significantly immediately after the start of the test. These differences occur because there is a lag between the time when the gas flows in the piping and the time when the projection material S is injected from the nozzle 15. Below, we will focus on the results for time periods when the numerical values ​​changed significantly.

[0064] As shown in Fig. 5, the AE parameter of the continuous injection remains almost constant at about 400, whereas the AE parameter of the intermittent injection fluctuates between about 100 and about 600. At this time, the pressure of the continuous injection shown in Fig. 6 remains almost constant at about 0.34 MPa, whereas the pressure of the intermittent injection fluctuates between about 0.34 MPa and about 0.53 MPa. Also, the flow rate of the continuous injection shown in Fig. 7 remains almost constant at about 600 L / min, whereas the flow rate of the intermittent injection fluctuates between about 0 L / min and about 600 L / min. The total amount of gas in the intermittent injection shown in Fig. 7 indicates a state in which it is 60% of the total amount of gas in the continuous injection.

[0065] In this way, it was revealed that when injection is performed so that the residual stress distribution of the workpiece after intermittent injection is the same as the residual stress distribution of the workpiece after continuous injection, the total amount of gas supplied to the nozzle in intermittent injection can be reduced to 60% of the total amount of gas supplied to the nozzle in continuous injection.

[0066] In addition, the total amount of gas supplied was changed between 20% and less than 100%, and tests were conducted under the same conditions as the above-mentioned tests, and the residual stress imparted to the workpiece was measured. The residual stress here is the integrated value of the residual stress distribution in the workpiece. As a result, it was revealed that if the total amount of gas in intermittent injection is between 20% and less than 100% of the total amount of gas in continuous injection, intermittent injection can efficiently impart residual stress to the workpiece W with a smaller total amount than continuous injection. [Explanation of symbols]

[0067] Reference Signs List 1...injection system, 10...injection device, 12...compressor, 15...nozzle, 15A...mixing section, 20...measuring device, 21...sensor, 22...AD conversion section, 23...communication section, 30...control device, 31...acquisition section, 32...injection control section, 33...management section, 34...intermittent injection control section, 35...memory section, 64...regulator, 65...first pressure sensor, 67...flow rate sensor, 68...second pressure sensor, 69...intermittent injection unit, S...projection material, W...work.

Claims

1. A method for spraying a blast material together with a gas onto a workpiece, comprising the steps of: acquiring a blast state of the blast material toward the workpiece; managing the supply of the gas based on the injection state of the projection material and intermittently ejecting the projection material toward the workpiece; A method for spraying a projection material, comprising:

2. 2. The method for spraying a projection material according to claim 1, wherein the spraying step adjusts at least one of a flow rate and a pressure of the gas to be supplied based on a spray state of the projection material, and sprays the projection material intermittently against the workpiece.

3. The obtaining step further includes obtaining a residual stress value required for the workpiece, 3. The method for spraying a projection material according to claim 1, wherein the step of spraying includes adjusting a spray time interval for each spray of the projection material based on a spray state of the projection material and the residual stress value, and spraying the projection material intermittently against the workpiece.

4. The acquiring step further includes acquiring surface information related to a surface state required for the workpiece, 3. The method for spraying a projection material according to claim 1 or 2, wherein the spraying step adjusts a spray time interval for each spray of the projection material based on the spray state of the projection material and the surface information, and sprays the projection material intermittently against the workpiece.

5. An injection device that injects a projection material together with gas toward a workpiece; A measuring device for measuring a state in which the projection material is sprayed onto the workpiece by the spraying device; A control device for controlling the injection device; Equipped with The control device includes: An acquisition unit that acquires the blast state of the projection material from the measurement device; an injection control unit that manages the supply of the gas based on the injection state of the projection material and controls the injection device so as to intermittently inject the projection material at the workpiece; having Projectile injection system.

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