JPH0446769A - Deburring device - Google Patents

Abstract

PURPOSE:To accurately detect a slurry density by providing a control device for opening and closing a switching valve for a predetermined time to control supply and stop of the slurry to a reservoir vessel while operating a polishing and cleaning material supplying mechanism is operated based on the output of sensors to maintain a slurry density constant in a liquid vessel. CONSTITUTION:A slurry circulating mechanism 20 for sucking the slurry in a liquid vessel 10 to supply it near an injection flow of a nozzle device 16, and a reservoir vessel 40 for receiving a part of the slurry from the slurry circulating mechanism 20 through a switching valve 42 are provided. Next, this switching valve 42 is opened and closed for a predetermined time to control supply and stop of the slurry to the reservoir vessel 40, while a polishing and cleaning material supplying mechanism 60 is operated on the basis of the output of sensors 44, 46 for detecting a precipitation quantity of the polishing and cleaning material of the resting slurry in the reservoir vessel 40 to maintain a slurry density constant in the liquid vessel 10.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention cleans a workpiece by spraying a high-pressure jet stream of a cleaning liquid onto the workpiece placed in a mixed fluid (slurry) of a cleaning liquid and an abrasive material. The present invention also relates to a deburring device for deburring a workpiece.

(Background of the Invention) In the process of manufacturing ICs (integrated circuits), when a circuit board connected to a lead frame is molded with resin, it is necessary to remove burrs and clean the resin that is generated during the molding process. It becomes necessary.

For this cleaning and deburring process, the applicant has proposed a method of spraying a mixed fluid (slurry) of a cleaning liquid such as water and an abrasive material such as glass beads (for example, (See Application No. 63-76157).

In this existing proposal, new cleaning liquid is injected from an injection nozzle, while the slurry in the liquid tank is circulated and mixed with the jet stream. Here, the cleaning and deburring effects are greatly affected by changes in slurry concentration and slurry liquid level. Therefore, when the liquid level in the liquid tank exceeds a certain level, a drainage mechanism is activated to keep the excess liquid at a constant level, but as the liquid is drained by this drainage mechanism, some of the abrasive material may also be discharged. become. Therefore, it is necessary to add an abrasive to keep the slurry concentration within a certain range.

Therefore, a control method can be considered that detects the slurry concentration and adds abrasive material when it becomes thin. For example, it is difficult to detect the slurry with high precision.For example, it is possible to constantly circulate the slurry in a glass tube and determine the concentration as it passes through the glass tube from the amount of light transmitted.However, in this case, it is difficult to detect the As the cleaning material becomes finer, the amount of transmitted light decreases, and the measured slurry concentration becomes higher than the actual concentration, making it difficult to obtain stable cleaning and deburring effects.

(Objective of the Invention) The present invention was made in view of the above circumstances, and it is possible to detect the slurry concentration with high precision, and it is possible to detect the slurry concentration without being affected by the miniaturization of the abrasive material. It is an object of the present invention to provide a deburring device that can stably clean and deburr a workpiece.

(Structure of the Invention) According to the present invention, this purpose is to hold a workpiece in a liquid tank containing a slurry of cleaning liquid and abrasive material, and to direct the workpiece through a nozzle device disposed above the liquid tank. A deburring device that deburrs a workpiece by spraying a high-pressure jet of cleaning fluid includes a slurry circulation mechanism that absorbs slurry in a liquid tank and supplies it near the jet of the nozzle device, and a slurry circulation mechanism that absorbs slurry in a liquid tank and supplies it to the vicinity of the jet of the nozzle device. a storage tank that receives a portion of the slurry via a switching valve; a sedimentation amount sensor that detects the amount of sedimentation of the abrasive material in the slurry that is stationary in the storage tank; and an abrasive material supply mechanism that supplies the abrasive material to the liquid tank. and control to control supply/stop of slurry to the storage tank by opening and closing the switching valve for a predetermined period of time, and to operate an abrasive material supply mechanism based on the output of the sensor to maintain a constant slurry concentration in the liquid tank. This is achieved by a deburring device characterized by comprising:

(Embodiment) FIG. 1 is an overall system diagram of an embodiment of the present invention, and FIG. 2 is an operation flowchart thereof.

In this figure, reference numeral 10 denotes a liquid tank, and this liquid tank 10 contains slurry, which is a mixed fluid of a cleaning liquid such as water and an abrasive material such as glass beads or grindstone powder. Work 12 is a lead frame with an IC circuit molded in resin.
This liquid tank 1 is transported by a work conveying means 14 such as a conveyor.
0 through the slurry.

Reference numeral 16 denotes a nozzle device that sprays cleaning liquid at high pressure from above the liquid tank 10 toward the work 12 in the slurry. For example, the nozzle device J6 has a nozzle diameter of 0.3 mm at the tip,
A cleaning liquid pressurized to approximately 700 kg/cm" is injected from this nozzle. At this time, the jet stream injected from the nozzle reaches a flow velocity of 380 m/sec, exceeding the speed of sound. This jet stream flows inside the liquid tank 10. The abrasive material collides with the workpiece 12, cleaning the workpiece 12 and removing burrs generated during resin molding.

20 is a slurry circulation mechanism, which sucks out slurry from near the bottom of the liquid tank 10 and sends it to an outlet 20b using a pump 20a.
It is sent to Since the abrasive material in the slurry is precipitated at the bottom of the liquid tank 1o, the slurry containing a large amount of abrasive material (that is, the slurry concentration is high) is sucked into the pump 20a. The outlet 2°b discharges this slurry toward the vicinity of the position where the jet stream from the nozzle device 16 hits the liquid surface. Therefore, the discharged thick slurry mixes with the jet flow and hits the workpiece 12, facilitating cleaning and deburring operations.

A filter 22 is provided in the middle of this slurry circulation path to separate burrs from the slurry. That is, a portion of the slurry is guided to the filter 22, and the permeate after burrs are captured by the filter 22 is collected by the funnel 24 and returned to the liquid tank 10.

30 is a liquid drainage mechanism, and a pump 30b sucks out the cleaning liquid from the slurry liquid in the liquid tank 10 through the filter 30a.
, a liquid level sensor 30c that detects the liquid level in the liquid tank 10, and a controller 30 that compares the output of the liquid level sensor 30c with a set value and controls the pump 30b to maintain the liquid level at a predetermined level.
d. Therefore, the liquid level in the liquid tank 10 is determined by the liquid level sensor 3.
When the temperature reaches 0c, the pump 30b starts and the filter 30a
The cleaning solution is sucked out and discharged through. filter 3 here
0a is provided to separate the abrasive material in the slurry and suck out only the cleaning liquid, but in reality, the abrasive material that collides with the workpiece 12 along with the jet stream is crushed or worn into fine particles. and a portion is discharged through the filter 30a.

40 is a slurry storage tank. This storage tank 40 is made of a transparent material such as glass and has a cylindrical shape. A part of the slurry is supplied from the pump 20a from the lower end of the tank 40 via an electromagnetic valve 42 as a switching valve, and from the upper end of the tank 40, the slurry is supplied into liquid form. Tank 1
The pipe is connected so that it returns to 0. This storage tank 40 has two pairs of transmission type optical sensors 44.4 at different heights.
6 is installed. That is, each sensor 44, 46 has light emitting elements 44a, 46a facing each other with the storage tank 40 in between.
and light receiving elements 44b and 46b, and the slurry concentration, that is, the amount of sedimentation of the abrasive material is detected from the amount of light transmitted between the multiple light receiving elements. This change in the amount of transmitted light is determined by the sensor amplifier 48.50.

60 is an abrasive supply mechanism. This mechanism 60 includes the liquid tank 1
a hopper 60a disposed above the hopper 60a for storing abrasive material;
Gear pump 6 installed at the abrasive material outlet of this hopper 60a
0b and a motor 60c that drives this gear pump 60b.
(bead supply motor) and a controller 60d that controls the motor 60c.

70 is a control device. This controller M70 is a solenoid valve 42
is opened or closed for a predetermined time, and the motor 60c is operated for a predetermined time to supply the abrasive material so that the slurry concentration is kept constant based on the output of the amplifier 48,50. That is, when the automatic operation mode in which the slurry concentration is automatically controlled to be constant is selected (FIG. 2, step 1oo), the control device 70 first opens the solenoid valve 42 to drain a portion of the slurry in the liquid tank 10 from the pump 20a. Storage tank 40
The slurry is circulated through the storage tank 40 for a predetermined period of time to stabilize the slurry concentration in the storage tank 40 (step 102). Thereafter, the 11M1 valve 42 is closed (step 104), and the apparatus is kept stationary for a predetermined period of time (for example, 2 minutes) to wait for the abrasive material such as glass beads to settle.

If the sensor 44 at the lower position detects precipitation (7), then
Step 106, NO), it is determined that the amount of sedimentation is small and the slurry is thin, and the off time of the motor (bead supply motor) 60c of the abrasive material supply mechanism 60 is shortened, for example, off time T.

is changed to a shorter T (step 108). In this embodiment, the on-time t of the motor 60c is always kept constant, and the supply amount of abrasive material is changed depending on the length of the off-time. is under control.

If the sensor 44 detects precipitation (step 106, YES)
If the sensor 46 located at a higher position does not detect precipitation (step 110, NO), the off time of the motor 60c is maintained (step 112).

When both sensors 44 and 46 detect sedimentation, the slurry is too thick (step 110, YES), so controller 70 extends the off time of motor 60C from T1 to T2 and reduces the amount of abrasive supplied.

And if you want to continue this automatic operation (step 1
16, No), return to step 102, replace the slurry in the storage tank 40, and repeat the above operation at predetermined time intervals. If you want to stop automatic operation (Step 1)
16, YES), return to step 100 and wait for automatic operation input.

In this embodiment, the amount of precipitation is detected using light transmission type sensors 44 and 46, but the present invention is not limited thereto. For example, detection may be performed using changes in capacitance or reflection of ultrasonic waves from the precipitation surface. Furthermore, since the fine abrasive material enters into the gaps between normal abrasive materials during sedimentation, the amount of sediment detected by the sensor is hardly affected by the fine abrasive material, and therefore deburring contributes. The normal amount of abrasive material can be detected with high precision.

Further, in the present invention, the supply of abrasive material is controlled by controlling the supply stop time (off time of the motor 60c) as in the embodiment.
It may be possible to change the supply time (on time of the motor 60c) or to continuously supply and change the supply flow rate.

(Effects of the Invention) As described above, the present invention allows the abrasive to settle by storing the slurry in the storage tank and making it stand still, and detects the amount of sedimentation to determine the slurry concentration, so the slurry concentration can be determined with high precision. can be detected.

Since the supply amount of the abrasive material is controlled by 4 degrees based on the output of this sensor, the slurry concentration can always be kept stable and constant. Therefore, by properly controlling the slurry concentration, stable cleaning and deburring effects can always be obtained.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram of an embodiment of the present invention, and FIG. 2 is an operational flowchart thereof. 10...Liquid tank, 12...Work, 16...
Nozzle device, 20... Slurry circulation mechanism, 22... Filter, 40... Storage tank, 42... Solenoid valve as a switching valve, 44. 46... Sedimentation amount sensor 60... Grinding Material supply mechanism, 70...control device. Patent applicant: Shibaura Seisakusho Co., Ltd.

Claims (1)

[Claims] A workpiece is held in a liquid tank containing a slurry of cleaning liquid and abrasive material, and a high-pressure jet of cleaning liquid is sprayed toward the workpiece from a nozzle device disposed above the liquid tank. A deburring device that deburrs a workpiece includes a slurry circulation mechanism that absorbs slurry in a liquid tank and supplies it to the vicinity of the jet of the nozzle device, and a part of the slurry from the slurry circulation mechanism via a switching valve. a storage tank for receiving the slurry, a sedimentation amount sensor that detects the amount of sedimentation of the abrasive material in the slurry that is stationary in the storage tank, an abrasive material supply mechanism that supplies the abrasive material to the liquid tank, and an abrasive material supply mechanism that operates the switching valve for a predetermined period of time. It is characterized by comprising a control device that opens and closes to control supply and stop of slurry to the storage tank, and operates an abrasive supply mechanism based on the output of the sensor to maintain a constant concentration of slurry in the liquid tank. Deburring equipment.