JP2764663B2 - Airblast method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air blasting method and apparatus for shot peening a product by spraying an abrasive material together with compressed air from a spray nozzle to impinge on the product.

[0002]

2. Description of the Related Art In recent years, in order to uniformly treat an article to be treated and improve the quality, a shot material to be sprayed always has a momentum within a set range and exerts a uniform shot peening effect on the quality. The demand for air blasting equipment is increasing. For this reason, the applicant of the present application measures the differential pressure between the entrance side and the exit side in the transport pipe and increases or decreases the amount of the abrasive material mixed into the compression air or the pressure of the compression air supplied to the transport pipe based on the measured differential pressure. An air blast method has been proposed (Japanese Patent Laid-Open No. 1-257565) in which the momentum of the abrasive material sprayed from the nozzle is maintained within a set range.

However, in this method, the momentum of the abrasive material, which is a control target, is controlled while measuring the differential pressure in the transport pipe, so that the momentum of the abrasive material is measured only indirectly. It was a reality that there was a slight difference between the actual momentum of the sweep material and the control was not performed with high accuracy. In particular, when processing the workpiece while rotating it, the difference between the measured momentum and the actual momentum is further increased because not all of the blasting material injected collides with the specific part and actually contributes to the sit peening process. There was a growing problem. The present invention has been made in view of the above problems, and is intended to control the pressure or the amount of the abrasive material while controlling the pressure or the amount of the abrasive material while directly measuring the momentum of the abrasive material as a final control target. It is an object of the present invention to provide an air blast method and an apparatus for maintaining a momentum of a sweeping material within a set range.

[0004]

Means for Solving the Problems In order to achieve the above object, the air blasting method of the present invention performs shot peening of a product by spraying an abrasive with a compressed air from a nozzle provided at the tip of a transport pipe. In the air blast method, a blasting material collision propagation member including a blasting material collision portion that is ejected to generate an elastic wave by colliding with the blasting material and a propagation member that propagates the elastic wave; A main body comprising a conversion member that receives the elastic wave from the propagation member and converts the elastic wave into a high-frequency electric signal; and a measurement circuit that detects the number of blasting material collisions and the blasting material collision strength based on the high-frequency electric signal. And, the main body part of the blast strength detector consisting of the abrasive material collision strength, by moving in and out of the position between the spray nozzle and the product, and the amount of collision of the abrasive material, the momentum set in advance and ratio While maintaining the pressure within the set range, the pressure of the compressed air supplied to the transport pipe, the amount of the abrasive material supplied into the transport pipe, or the injection time of the abrasive material is increased or decreased. It is characterized by doing.

[0005]

The present invention measures the actual momentum of the abrasive material injected from the injection nozzle by adopting the above-mentioned solution, and based on the measurement result, the supply amount of the abrasive material and the compression air. The shot peening process can be performed while maintaining the momentum of the abrasive material within a certain range by controlling the pressure or the injection time of the abrasive material, and a highly accurate homogeneous shot peening effect can be obtained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a blast intensity detector will be described with reference to FIGS. In FIG. 1, a plate-shaped blasting material collision propagation member 1 serving as both a blasting material collision portion where an injected blasting material S collides to generate an elastic wave and a propagation portion that propagates the elastic wave is provided. , And is fixed to the outer case 3 via an annular vibration-proof rubber 2. The abrasive material collision propagation section 1 has a diameter 20 made of a wear-resistant material such as carburized steel or cemented carbide ceramic.
mm and a thickness of 10 mm (other dimensions may be used), and both surfaces are polished. In addition, the abrasive material collision propagation member 1 may be a composite material in which the collision member and the propagation member are bonded. The outer case 3 is formed in a box shape having a substantially square upper surface and a lower surface, and an opening 11 for mounting the abrasive material collision propagation member 1 through the vibration isolating rubber 2 is formed on the upper surface, and the side surface is formed on the side surface. A wiring hole 12 is formed. A converter (AE sensor) 4 for receiving an elastic wave to be propagated, converting the signal into a high-frequency electric signal, and outputting the signal is attached to the lower surface of the blast material collision propagation member 1. The converter 4 is connected to a cable 5 passing through a wiring hole 12 of the outer case 3, and the cable 5 is connected to a measuring circuit K.

Now, the measuring circuit K will be described with reference to FIG. 2. An envelope detection circuit 6 for converting a high-frequency electric signal into an envelope detection is connected to the end of the cable 5 via an amplifier circuit 6A. The line detection circuit 6 is connected to a counter circuit for detecting the number of occurrences of the envelope detection and a peak measurement circuit 8 for detecting the peak value of the envelope detection.

[0008]

[Embodiment 1] Next, an apparatus for performing air blast using a detector having such a blast strength will be described. In FIG. 3, a mixing valve 22 is attached to an outlet of a pressure vessel type abrasive cleaning material storage tank 21, and one end of the mixing valve 22 has a pipe 23, an on-off valve 24, a pressure reducing valve 25,
And a mixing valve 22 connected to a compression air source (not shown) through a stop valve 26.
The other end is communicated with the abrasive nozzle 28 through a transport pipe 27. Further, an inlet 29 is formed at an upper position in the abrasive material storage tank 21, and the inlet 2
Numeral 9 is adapted to be opened and closed by a valve body 30 arranged so as to be able to move up and down. The valve body 30 is raised by the compressed air discharged from the upward compressed air discharge pipe 31 so as to close the inlet 29, and the discharge pipe 3 is closed.
Numeral 1 is connected to a position downstream of the pressure reducing valve 25 in the pipe 23 via an on-off valve 32 and a pipe 33.

Further, an electric damper 34 for continuously changing the opening degree of the supply port is attached to the polishing material supply port of the mixing 22. In front of the spray nozzle 28, a product W is mounted on a rotating machine 36 whose rotation speed is changed by a rotation speed adjustment degree 35, and the blast strength is provided between the spray nozzle 28 and the product W. The main body 10 of the detector is a piston rod 39 of a downward cylinder 38.
It is attached to the tip and can be moved up and down. Note that the piston rod 39 is formed in a hollow tubular shape, and the cable 5 is wired in a hollow portion of the piston rod 39. The end of the cable is electrically connected to the measurement circuit K, K is electrically connected to a controller 40 composed of a microcomputer. The controller 40 is electrically connected to the electric damper 34 and the on-off valve 24, respectively. In the drawing, reference numeral 41 denotes an exhaust on-off valve.

[0010] With the above-mentioned structure, the following is performed before the shot peening processing operation is performed.
That is, in a state where the main body portion 10 of the blast intensity detector is moved above the injection area of the injection nozzle 28 by the downward cylinder 38, the on-off valve 32 is closed, the exhaust on-off valve 41 is opened, and the compression air is discharged to release the valve. The body 30 is lowered. Next, the blasting material S is charged into the blasting material storage tank 21, and the on-off valve 41 is closed and the on-off valve 32 is opened to raise the valve body 30 to fill the tank 21 with compressed air.
After the inside of the tank 1 reaches a predetermined pressure, the opening / closing valve 24 is opened, the compression air is sent to the mixing valve and ejected from the injection nozzle 28, and then the electric damper 34 is opened to transport the abrasive S in the tank 21 from the mixing valve 22. It is made to flow into the pipe 27 and is jetted from the tip of the jet nozzle 28 together with the compressed air.

Here, the cylinder 38 is operated to allow the main body 10 of the blast intensity detector to pass through the front of the injection nozzle 28 at a predetermined speed. At this time, a large number of the blasting material S injected collides with the blasting material collision propagation member 1, and the blasting material collision propagation member 1 catches the collision to generate an elastic wave, which is transmitted to the converter 4. The received high-frequency electric signal is converted to a high-frequency electric signal and output. The high-frequency electric signal is output to the envelope detection circuit 6 via the cable 5 via the amplifier circuit 6A of the measurement circuit.
A signal is output from the envelope detection circuit 6 to which the high-frequency electric signal has been input to the counter circuit 7 and the peak measurement circuit 8 so that the number of occurrences of the envelope detection (the number of collisions of the polishing material) and the peak value of the envelope detection (the polishing material) Impact strength) are each measured.

Here, the relationship between the momentum at the time of one collision of the abrasive material and the output of the blast intensity detector is proportional as shown in FIG. Therefore, the total momentum per predetermined time can be measured by multiplying the momentum at the time of collision with the polishing agent by the number of collisions of the abrasive per predetermined time. Thereafter, the measured total amount of exercise per predetermined time is input to the controller 40, and the electric damper 34 is controlled based on the value of the amount of exercise. That is, the electric damper 34 can control the momentum by opening the supply port of the mixing valve 22 when the measured momentum is lower than the set momentum, and by narrowing the supply port of the mixing valve 22 when the measured momentum is higher than the set momentum.

As a result, the momentum of the abrasive material injected from the injection nozzle 28 is maintained within a certain range.
In the above embodiment, the main body 10 of the blast strength detector is moved up and down by the downward cylinder 38, but may be moved in the horizontal direction, and a link mechanism may be used as a moving means. Further, in the first embodiment, when the amount of exercise per predetermined time is input to the controller 40, the amount of exercise at the scheduled cleaning end time is predicted and integrated based on the input value, and the integrated value is compared with the amount of exercise set in advance. The momentum of the abrasive S colliding with the product W can be changed by changing the abrasive injection time by the opening time of the on-off valve 24.

[0014]

Second Embodiment FIG. 5 is different from FIG. 3 in that the pressure reducing valve 25 in FIG. 3 is a proportional pressure control valve 45, and other components are the same as those in FIG. 45 is electrically connected to the controller 40, and the connection between the electric damper 34 and the controller 40 is eliminated. Therefore, before performing the shot peening process, the momentum per predetermined time by the blast intensity detector is input to the controller 40 in the same manner as in the first embodiment of FIG. 3, and the proportional pressure control valve 45 is driven based on this. Thus, the pressure of the compression air is increased or decreased so as to have a predetermined momentum. As a result, the momentum of the abrasive material injected from the injection nozzle 28 is maintained within a certain range. Further, similarly to the first embodiment, the momentum can be changed by changing the injection time of the abrasive. Further, the electric damper 34 and the proportional pressure control valve 45 may be controlled simultaneously by combining the first and second embodiments.

[0015]

As is apparent from the above description, according to the present invention, while measuring the momentum of the abrasive material to be sprayed, the amount of the abrasive material mixed into the compression air based on the measured momentum and the compression supplied to the transport pipe. Shot peening is performed by increasing or decreasing the air pressure or the abrasive material projection time to maintain the momentum of the abrasive material sprayed from the spray nozzle within the set range, so that products with uniform quality are suitable. Excellent effects such as being able to be surely obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main body of a blast intensity detector.

FIG. 2 is a block diagram showing a measurement circuit of the blast intensity detector.

FIG. 3 is a schematic diagram showing an embodiment of the present invention.

FIG. 4 is a graph showing the relationship between the momentum of the abrasive and the output of the detector.

FIG. 5 is a schematic view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polishing material collision propagation member 4 Transducer 7 Counter circuit 8 Peak measuring circuit 10 Body part of blast strength detector 21 Polishing material storage tank 22 Mixing valve 24 On-off valve 28 Injection nozzle 34 Electric damper 40 Controller 45 Proportional pressure Control valve K Blast strength detector measurement circuit S Polishing material W Product

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B24C 7/00

Claims (3)

(57) [Claims] 1. An air blasting method for shot peening a product by injecting an abrasive material together with a compressed air from an injection nozzle provided at the tip of a transport pipe, and causing the injected abrasive material to collide with an elastic wave. blast comprising a propagation member which propagate generated abrasive cleaning agent collision portion and said acoustic wave
A timber collision propagating member, the Institute cleaning agent and a body portion which consists of a conversion member for converting the high frequency electric signal said receive acoustic waves from the collision propagating member, the high frequency electric signal to the basis Labs cleaning agent number of collisions and A blast strength detector comprising a measuring circuit for detecting the blasting material collision strength, and moving the main body part into and out of a position between the spray nozzle and the product, thereby causing the blasting material collision strength and the blasting material collision. The amount is measured and compared with a preset momentum, the pressure of the compression air supplied to the transport pipe, the amount of the abrasive material supplied into the transport pipe, or the injection time of the abrasive material is increased or decreased, and the injection is performed. An air blast method comprising maintaining the momentum of the abrasive material within a set range. 2. One end of a mixing valve mounted at the discharge port of the abrasive material storage tank is connected to a compression air source via an on-off valve and a decompression valve, and the other end of the mixing valve is injected via a transport pipe. An air blast device in which nozzles are connected and connected, and an electric damper that continuously changes an opening degree of the supply port is attached to an abrasive supply port of the mixing valve, wherein the injected abrasive material collides. A blasting material collision portion that generates an elastic wave by the blasting material and a blasting material collision propagation member including a propagation member that propagates the elastic wave; and a high-frequency electric signal that receives the elastic wave from the blasting material collision propagation member. And a measuring circuit for detecting the number of blasting material collisions and the blasting material collision strength based on the high-frequency electric signal, and the blasting strength detector comprising the main body portion. , The injection An air blast device, wherein the air blast device is provided so as to be able to enter and exit between a nozzle and a product, and a measuring circuit of the detector is electrically connected to the electric damper via a controller including a microcomputer. 3. One end of a mixing valve attached to the discharge port of the polishing material storage tank is connected to a compression air source via an on-off valve and a proportional pressure control valve, and the other end of the mixing valve is connected to a transport pipe via a transport pipe. An air blasting device in which an injection nozzle is connected in communication with an abrasive material, wherein the abrasive material includes an abrasive material collision portion that generates an elastic wave by collision of the injected abrasive material, and an abrasive material collision device that includes a propagation member that propagates the elastic wave. A main body portion including a propagation member, a conversion member that receives the elastic wave from the cleaning material collision propagation member, and converts the elastic wave into a high-frequency electric signal; A measuring circuit for detecting a material collision strength, the main body of the blast strength detector comprising: To my An air blasting device electrically connected via a controller comprising a microcomputer.