JP3291205B2 - Magnetic polishing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to magnetic polishing used mainly for deburring and surface polishing of pressed parts such as hoop-shaped metal sheets, such as electric razor blades, relay parts, microswitch parts and connector parts. Regarding the method,
More specifically, the present invention relates to a technique for stabilizing the amount of magnetic powder in a portion where magnetic polishing is performed, thereby improving processing efficiency and processing quality.

[0002]

2. Description of the Related Art Conventionally, as a method of supplying magnetic powder in magnetic polishing, as shown in JP-A-3-202267 shown in FIG. Is to be supplied to

[0003]

However, in such a method, magnetic polishing such as press deburring of a metal hoop material after press working or surface polishing of a razor blade can be effectively used. Thought,
Magnetic polishing of such a metal hoop material has the following problems.

1) Since it is a long object, it is necessary to continuously process it. However, as shown in the conventional example, there is no means capable of continuously supplying magnetic powder such as a magnetic grindstone or iron powder. The processing efficiency is low because the processing is stopped.

[0005] 2) Only by continuously supplying magnetic powder,
The magnetic powder adheres to the workpiece and is taken out, or the magnetic powder flows out due to a machining fluid such as a polishing liquid or lapping oil, and the amount of magnetic powder present in the machining area changes, resulting in machining efficiency and processing quality. Is unstable.

The present invention is intended to solve such a problem, and an object of the present invention is to continuously supply magnetic powder and to stabilize the amount of magnetic powder at a processing location.
An object of the present invention is to provide a magnetic polishing method capable of stabilizing processing efficiency and processing quality.

[0007]

According to the first aspect of the present invention, a drivable iron core 1 and a coil 2 for applying a magnetic force to the iron core 1 are provided. In a magnetic polishing method in which a liquid abrasive is separately supplied and processed, the amount of magnetic powder 3 present in a processed portion during magnetic polishing is detected, and the supply amount of magnetic powder 3 is controlled based on the detection information. to, the amount of magnetic powder 3 of the section so as to kept constant, pressurized
The detecting means for detecting the amount of magnetic powder in
Of yoke 7 in the magnetic circuit constituting the magnetic circuit providing the
Is provided to form a gap G, and the gap G
The magnetic flux density is detected, and based on the detection result,
The feature is to measure the amount of the magnetic powder 3 existing in the gap 8 between the two .

According to the second aspect of the present invention, the magnetic properties of the processed portion
Processing part that performs magnetic polishing on the detection means that detects the amount of powder
Is magnetically polished in the processing part for the processing head 9
Provided on the downstream side of the workpiece W in the feed direction and attached to the workpiece W
It is characterized by measuring the amount of magnetic powder 3 taken out .

According to the third aspect of the present invention, a drivable iron is provided.
A core 1 and a coil for applying a magnetic force to the iron core 1
Magnetic powder 3 is magnetically adsorbed on the
In the magnetic polishing method of feeding and processing,
Detects the amount of magnetic powder 3 present in the processing section,
The supply amount of the magnetic powder 3 is controlled based on the
3 to keep the amount constant, and check the amount of magnetic powder in the processed part.
Knowledge to the sensing means, guide rolls to guide the engineering crop W
Force sensor like load cell 11 at the shaft end of 10,10
12 and the force applied to the workpiece W by the force sensor 12
Detect and measure the amount of magnetic powder 3 present in the machined part.
It is characterized by the following.

According to a fourth aspect of the present invention, a mono-type pon
The magnetic powder 3 to be supplied to the pump 13 is mixed with a liquid surfactant 39.
It is characterized by being mixed and supplied .

In the invention of claim 5, the surfactant 3
9. Propylene glycol dispersant or polycarbohydrate
Use of phosphates and phosphates
It is characterized by the following.

According to a sixth aspect of the present invention, there is provided a mono-type
The magnetic powder 3 to be supplied to the pump 13 is converted into a high-viscosity gel-like substance 40.
And mixed and supplied .

In the invention according to claim 7, the gel-like substance 4
0 is characterized by being water-soluble .

According to the configuration of the first aspect, the amount of the magnetic powder 3 in the processing section can be constantly monitored and controlled to be constant, and the processing efficiency and the processing quality can be stabilized. Further, a gap G is provided in the magnetic circuit.
The amount of the magnetic powder 3 can be controlled by detecting the magnetic flux density
It can be easily detected.

According to the second aspect of the present invention, the gap between the processing portions is provided.
Even if the portion 8 is wide and the diameter of the iron cores 1 and 1 is large,
Magnets attached to the workpiece W without being affected
By detecting the amount of the conductive powder 3, the magnetic powder 3
Can easily be detected.

According to the third aspect of the present invention, the magnetic loss (additional
Detecting the amount of magnetic powder 3 without lowering the process efficiency)
Can be.

According to the fourth aspect of the present invention, in the supply medium,
Magnetic powder 3 can be evenly dispersed and stable supply
Becomes possible.

[0018] In this case, the interface may be configured as described above.
A propylene glycol-based dispersant or
Uses those selected from recarboxylates and phosphates
Is preferred.

According to the sixth aspect of the present invention, in the supply medium,
The magnetic powder 3 can be uniformly dispersed, and sedimentation can be prevented.
And stable supply becomes possible.

[0020] In this case, as in the structure of claim 7, the gel
Preferably, the particulate matter is water-soluble.

[0021]

FIG. 1 shows an embodiment of a magnetic polishing apparatus used for a magnetic polishing method according to the present invention.
Is sent in a direction perpendicular to the plane of the paper. Iron cores 1 and 1 facing each other are provided on both sides of the workpiece W with a substantially constant gap 8 therebetween. Coils 2 and 2 are provided around the iron cores 1 and 1 by winding copper wires around the cores. A direct current is supplied to both coils 2 and 2 so that the opposing surfaces of the iron cores 1 and 1 have opposite polarities. A substantially U-shaped yoke 7 is provided on the side of the iron core 1 opposite to the surface facing the workpiece W to form a magnetically closed circuit.
The iron core 1 is rotatably supported and can be driven to rotate by a motor 14. The driving method may be oscillating motion or ultrasonic vibration.

The magnetic powder 3 is an atomized iron powder having a particle diameter of 50.
The one having a thickness of about 200 μm is used. Processing fluid is $ 100
A water-soluble polishing liquid containing about 0 to about $ 10,000 WA abrasive grains, a surfactant, an antifoaming agent, and water is used. In addition, a magnetic abrasive material obtained by mixing iron powder and abrasive grains as a magnetic powder 3 and sintering, and a water-soluble grinding liquid or a lapping oil as a working liquid can be suitably used. In this embodiment, the magnetic powder 3 is mixed with a polyacrylic acid-based thickener, a propylene glycol-based dispersant, and a high-viscosity gel-like substance containing water at a weight ratio of about 30 to 80%. I have.

As a supply source of the magnetic powder 3, a well-known mono type having a uniaxial eccentric screw type rotor having a circular cross section and a stator having a rectangular cross section, and transferring a substance filled in both spaces from a suction side to a discharge side. The pump 13 is used, and a stepping motor 35 whose rotation speed can be controlled arbitrarily and with high accuracy is used as a drive source of the mono pump 13.
The rotation shaft of the stepping motor 35 and the rotation shaft of the mono pump 13 are fastened by a coupling joint 18.

The magnetic powder 3 mixed with the gel-like substance 40 is filled in a hopper 19 provided at the suction port of the mono pump 13, and the filled magnetic powder 3 is rotated by the stepping motor 35 through the mono pump 13. Thus, an amount proportional to the rotation speed is discharged from the discharge port 20.

A tube 21 is connected to the discharge port 20 via a joint.
Is connected, and the tube 21 extends to the side or above the gap 8 between the iron core 1 of the processing portion and the workpiece W.

The polishing liquid is also applied to the iron core 1 of the processing part and the workpiece W
A nozzle 22 is provided on the side of or above the gap 8 between the nozzles, and a liquid sent from a polishing liquid pump (not shown) is discharged to the processing section. Note that the supply liquid amount can be arbitrarily adjusted according to the processing state.

A minute gap G is provided in the yoke 7,
The thin magnetic sensor 23 is inserted into the gap G, and the magnetic flux density in the gap G is measured.

The value of the measured magnetic flux density is represented by a Gauss meter 24.
Is output as an analog voltage value from the output terminal of the data processing device 25 and enters the input terminal of the data processing device 25.

The data processing device 25 A / D converts the data of the analog voltage value at a desired sampling frequency,
Record the value of the magnetic flux density over time.

When the exciting current to the coil 2 is constant, and when the amount of the magnetic powder 3 in the processed portion increases, the apparent magnetic permeability in the gap 8 between the workpiece W and the end face of the iron core 1 becomes smaller. Since this corresponds to an increase, the magnetic flux density between the opposed iron cores 1 and 1 increases, and the magnetic flux density flowing through the yoke 7 also increases.

Conversely, when the amount of the magnetic powder 3 in the processed portion decreases, the magnetic flux density flowing through the yoke 7 decreases. Therefore, it is possible to detect a change in the amount of the magnetic powder 3 in the processed portion as a change in the value of the magnetic flux density. If the relationship between the amount of the magnetic powder 3 and the magnetic flux density is grasped in advance, the magnetic flux density at that time can be detected. It can be easily understood how many grams the amount of the magnetic powder 3 corresponds to (see FIG. 2).

If the detected value exceeds the predetermined range of the amount of the magnetic powder 3, a command to change the rotation speed of the stepping motor 35 is issued to the controller 36 for controlling the stepping motor 35, and The frequency signal of the motor driver 37 is increased or decreased so as to change the supply amount by an error from a predetermined amount of the magnetic powder 3 such that the rotation speed decreases if the amount is large and the rotation speed increases if the amount is small (see FIG. 3). .
A personal computer or the like can be suitably used for the data processing device 35 and the controller 36.

Thus, in the first aspect of the present invention,
Since the amount of the magnetic powder 3 is constantly monitored and controlled to be constant, stable processing efficiency and processing quality can be obtained.

Further, according to the first aspect of the present invention, the gap G is provided by dividing the yoke 7 in the magnetic circuit , and the magnetic flux density in the gap G is detected. The amount of the magnetic powder 3 existing in the gap 8 is measured, and the amount of the magnetic powder 3 is easily detected by providing a gap G in the magnetic circuit and detecting the magnetic flux density at this location. You can do it.

More specifically, as shown in FIG. 4, a brass plate 7c is interposed between the yoke members 7a and 7b and the brass bolt 3
8 to form a gap G,
The head of the magnetic sensor 23 is inserted into the sensor to detect the magnetic flux density at this point.

FIG. 5 shows an embodiment of the second aspect of the present invention . When the gap between the magnetic poles (iron core 1) of the processing head 9 is large and the head diameter is large, the space volume between the magnetic poles is large. Magnetic sensor 2
The change in the magnetic flux density of the head insertion portion of No. 3 is at a level that cannot be detected. The present invention is used for detecting the amount of the magnetic powder 3 in the case described above, and since the gap 8 at the magnetic pole portion for detection is small, the change in the amount of the magnetic powder 3 is slight. Even if there is, it can be detected.

That is, the same coil 2d and yoke 7 as in FIG.
d is provided separately from the machining head 9 on the downstream side in the feed direction of the workpiece W, a gap Gd of about 1 mm is provided at the center of a substantially U-shaped yoke 7d, and the workpiece W is caused to flow through the center.

A gap Ge similar to that shown in FIG. 1 is provided at the corner of the substantially U-shaped yoke 7d, and the head of the magnetic sensor 23 is inserted.

When the workpiece W is made of a magnetic material such as iron, the magnetic powder 3 adheres to the workpiece W and is taken out of the workpiece W.
The amount of the magnetic powder 3 that is magnetically attracted to the magnetic pole of the detection portion downstream and adheres to the magnetic pole end surface and thus adheres to the magnetic pole with the elapse of the processing time of the workpiece W increases, and accordingly, the detection portion Magnetic flux density also increases. Thus, the magnetic flux density after a certain period of time is set to be measured every time, it is determined whether the value of the magnetic flux density is a predetermined value, and the amount of the magnetic powder 3 existing in the machining head 9 is determined. Guess.

When the magnetic flux density is smaller than the predetermined magnetic flux density, the amount of the magnetic powder 3 attached to the workpiece W is small and the amount of the magnetic powder 3 existing in the machining head 9 is small. Of the motor controller 36 to increase the rotation speed. On the other hand, if it is larger, a command to lower the rotation speed is issued. After the measurement of the magnetic flux density, the exciting current of the coil 2d is once turned off, and the magnetic powder 3 existing between the magnetic poles is dropped and removed. At this time, depending on the case, it may be blown off with compressed air or may be made to flow with running water. Thereafter, the exciting current of the coil 2d is turned on again, and measurement of the magnetic flux density is started.

FIG. 6 shows an embodiment of the third aspect of the present invention .

The workpiece W is sent from right to left in the drawing. The workpiece W is sent while being wound around and guided by a pair of circular guide rolls 10 and 10a. Iron core 1 is workpiece W
And a substantially U-shaped yoke 7 is provided on the side opposite to the surface facing the workpiece W, and the other end surface of the yoke 7 faces the end surface of the iron core 1 with a certain gap. , Magnetically closed circuit.

The iron core 1 is rotatably supported, and is rotatably driven by a motor (not shown). The shaft ends of guide rolls 10a and 10a near both sides of the processing head 9 are fitted to bearings 26, and the bearings 26 are fitted and supported by bearing cases 27. The bearing case 27 is fixed to a box-shaped load cell 11, which is an example of the force sensor 12, and the load cell 11 can detect a vertical compression force. Load cell 11
The force detected by the amplifier is amplified by the amplifier, and is taken in from the output terminal of the amplifier into the same data processing device 25 as in FIG. The magnetic powder 3 is supplied in the same manner as in FIG. 1 and then the magnetic polishing is started, and at the same time, the detection of the force by the load cell 11 is also started. When the amount of the magnetic powder 3 is stable, a constant polishing pressure is applied to the workpiece W, so that a constant force is also detected in the load cell 11. However, when the amount of the magnetic powder 3 increases, Since the polishing pressure on the object W increases and the force applied to the load cell 11 also increases, if the relationship between the amount of the magnetic powder 3 and the load detected by the load cell 11 is grasped in advance, the monitoring of the load detected by the load cell 11 allows the magnetic powder 3 to be monitored. This makes it possible to detect the amount of

According to the third aspect of the present invention , the amount of the magnetic powder 3 can be detected without lowering the processing efficiency because there is no magnetic loss as compared with the method in which the gap G is provided in the middle of the yoke 7. . Further, the breakage of the workpiece W can also be detected .

FIG. 7 shows a main part of an embodiment of the fourth aspect of the present invention .

In general, the Mohno pump 13 has a disadvantage that the rotor and the stator are quickly worn out when the magnetic powder 3 is supplied as it is because the spiral rotor and the stator are fitted to each other. In order to prevent this, a method in which the magnetic powder 3 is mixed with water and supplied is conceivable. However, with water alone, there is a disadvantage that the magnetic powder 3 (iron powder) immediately sinks and hardens.

As a countermeasure against this, the invention of claim 4 utilizes the fact that the surfactant 39 has a role of uniformly dispersing the abrasive and enhancing the lubricating ability. By mixing the viscous surfactant 39 such as an ester and the magnetic powder 3 and supplying the mixture to the mono pump 13, wear of the rotor and the stator of the mono pump 13 is prevented, and sedimentation of the magnetic powder 3 is prevented. The supply is stabilized by dispersion.

FIG. 8 shows a main part of an embodiment of the invention of claim 6 .

According to a sixth aspect of the present invention, as in the fourth embodiment , a high viscosity gel-like substance 40 is used in place of the surfactant 39, and the rotor and the rotor of the mono pump 13 are used. The wear of the stator is prevented. The components of the gel-like substance 40 have been described in detail in the first claim and will not be described.

By the way, the magnetic powder 3 to be supplied depends on the driving source.
The rotational speed such as a servo motor or stepping motor and
Rotary, vibration, and
Compressed air is applied to the discharge port 16 of
Connect to a flowing pipe and press the magnetic powder 3 with air pressure.
In one embodiment, the magnetic head supply device is provided with a processing head 9 having a coil 2 similar to that shown in FIG. 1 and a yoke 7 similar to that shown in FIG. ), A vibration type, an auger type, etc., and a servomotor or a stepping motor capable of arbitrarily controlling the rotation speed with high precision as a driving source.

FIG. 9 shows an example in which a rotary feeder is used for the powder supply device.

The rotary feeder 30 cuts out the powder filled in the hopper 31 from the gap between the hopper 31 and the rotary table to the outside of the hopper 31 by rotating the impeller, and discharges the magnetic powder 3 cut out on the outer peripheral portion from the discharge port 32. Discharge. A substantially inverted conical hopper 3 is provided at the discharge port 32 of the rotary feeder 30.
1, a pipe 33 through which compressed air flows is connected to a lower end of the hopper 31 via a joint 34, and the pipe 33 through which compressed air flows has an end face disposed on the side or above the gap 8 of the processing head 9. Has been established.

After the magnetic powder 3 exits from the discharge port 32, it falls into the hopper 31, stays at the lower part of the hopper 31, and is sucked into the pipe 33 by the back pressure of the compressed air, and the gap 8 of the processing head 9 is formed. Is sent to the vicinity of and discharged. The discharged magnetic powder 3 is magnetically attracted and enters the gap 8 having the highest magnetic flux density. At this time, the pressure and the flow rate of the supply air are appropriately adjusted so that the magnetic powder 3 and the polishing liquid in the gap 8 are not scattered.

Thus, even if the supply amount is very small, the supply can be controlled with high precision, and there is no pulsation, so that stable fixed amount supply is possible and no binder is required.

[0055]

According to the first aspect of the present invention, there is provided a drivable iron core and a coil for applying a magnetic force to the iron core. The magnetic powder is magnetically attracted to the iron core, and a separate liquid abrasive is supplied. In the magnetic polishing method of processing, the amount of magnetic powder present in the processed part during magnetic polishing is detected, and the supply amount of the magnetic powder is controlled based on the detection information, and the amount of magnetic powder in the processed part is controlled. Since it is made constant, the amount of magnetic powder in the processing section can be constantly monitored and controlled to be constant, and there is an advantage that the processing efficiency and the processing quality can be stabilized. Furthermore, detect the amount of magnetic powder in the processed part
The detecting means is a magnetic circuit forming a magnetic circuit for applying a magnetic force to the iron core.
The yoke part in the air circuit is divided to provide a gap,
The magnetic flux density in the gap is detected, and based on this detection result,
The amount of magnetic powder present in the gap between the iron cores
From this, a gap is provided in the magnetic circuit to
Easy detection of the amount of magnetic powder by detecting the degree
There is an advantage that can be.

According to the second aspect of the present invention, the magnetic properties of the processed portion
Processing part that performs magnetic polishing on the detection means that detects the amount of powder
That the head is magnetically polished at the processing part
Installed on the downstream side of the crop feed direction, attached to the workpiece and taken out
Since the amount of magnetic powder to be measured is measured, the gap
It is not affected by these, even if the diameter of the iron core is large.
To detect the amount of magnetic powder attached to the workpiece and taken out.
This makes it easy to detect the amount of magnetic powder in the processed part.
It has the advantage of being able to handle it.

According to the third aspect of the present invention, the drivable iron
It consists of a core and a coil that applies magnetic force to the iron core, and the iron core is magnetic
The powder is magnetically adsorbed, and a separate liquid abrasive is supplied
The magnetic polishing method to be used
The amount of magnetic powder present is detected, and based on the detected information,
Controls the supply of conductive powder to keep the amount of magnetic powder in the processing section constant
Detecting means for detecting the amount of magnetic powder in the processed part
Is set on the shaft end of the guide roll that guides the workpiece.
A force sensor like the
Detects applied force and measures the amount of magnetic powder present in the machined part
Magnetic loss (reducing processing efficiency)
There is an advantage that the amount of the conductive powder can be detected.

According to a fourth aspect of the present invention, a mono-type
Magnetic powder to be supplied to the
Supply, the magnetic powder should be evenly dispersed in the supply medium.
The advantage is that stable supply is possible.
You.

According to the sixth aspect of the present invention, the mono-type
Mix the magnetic powder to be supplied to the
Disperse magnetic powder evenly in the supply medium because it supplies
Can prevent sedimentation and provide a stable supply.
The advantage is that

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the amount of magnetic powder and the magnetic flux density in a gap.

FIG. 3 is a flowchart illustrating a supply process of a magnetic powder.

FIG. 4 shows a gap, (a) is a horizontal sectional view, (b)
Is a side sectional view.

FIG. 5 is a diagram for explaining the invention of claim 2;

FIG. 6 is a diagram for explaining the invention of claim 3 ;

FIG. 7 is a schematic diagram of a case where a surfactant and a magnetic powder according to the invention of claim 4 are mixed.

FIG. 8 is a schematic view showing a case where a high-viscosity gel-like substance and a magnetic powder according to the invention of claim 6 are mixed.

FIG. 9 is a diagram illustrating another embodiment .

FIG. 10 is a sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Iron core 2 Coil 3 Magnetic powder 5 Polishing member 7 Yoke 8 Gaps 9 Processing head

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-42476 (JP, A) JP-A-5-8169 (JP, A) JP-A-6-226633 (JP, A) 13518 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24B 31/112 B24B 37/00 B24B 57/00

Claims (7)

(57) [Claims] 1. A magnetic polishing method comprising a drivable iron core and a coil for applying a magnetic force to the iron core, magnetically adsorbing magnetic powder on the iron core, and separately supplying a liquid abrasive to process the magnetic polishing method. Detecting the amount of magnetic powder present in the processing part during magnetic polishing, controlling the supply amount of the magnetic powder based on the detection information, and stabilizing the amount of magnetic powder in the processing part,
Detection means to detect the amount of magnetic powder
The yoke portion in the magnetic circuit that composes the magnetic circuit
Gap, and detect the magnetic flux density in this gap.
And based on this detection result,
A magnetic polishing method comprising measuring the amount of magnetic powder . 2. A detecting means for detecting an amount of magnetic powder in a processing portion.
To the processing head of the processing part that performs magnetic polishing
Downstream of the workpiece to be magnetically polished
Measure the amount of magnetic powder attached to the workpiece
2. The magnetic polishing method according to claim 1, wherein: 3. A drivable iron core and applying a magnetic force to the iron core.
It consists of a coil, magnetically adsorbs magnetic powder on the iron core,
In the meantime, a magnetic polishing method that supplies and processes a liquid abrasive
To detect the amount of magnetic powder present in the processed part during magnetic polishing
Control the supply amount of magnetic powder based on the detection information.
To keep the amount of magnetic powder in the processing section constant.
Detection means for detecting the amount of magnetic powder
Force sensor like a load cell at the end of the guide roll shaft
The force sensor detects the force applied to the workpiece and
Measuring the amount of magnetic powder present in the machined part
Magnetic polishing method that. 4. The method of claim 1 , wherein the magnetic powder to be supplied to the mono pump is a liquid.
Characterized in that it is supplied in the form of a mixture with a surfactant in the form of a powder.
The magnetic polishing method according to claim 1 or claim 3 . 5. A propylene glycol-based surfactant.
Choose from dispersants or polycarboxylates, phosphate esters
The magnetic polishing method according to claim 4, wherein the magnetic polishing method is performed. 6. The magnetic powder to be supplied to the Mohno pump is
It is characterized in that it is supplied by mixing with a viscous gel substance
The magnetic polishing method according to claim 1 or 3 . 7. The gel-like substance is water-soluble.
7. The magnetic polishing method according to claim 6, wherein: