JPS5830533A - Magnetic particle type electromagnetic coupling device - Google Patents

Abstract

PURPOSE:To improve the durabiity of an electromagnetic coupling device and transmit a torque efficiently by a method wherein the coupling surface of a magnetic particle type electromagnetic coupling device is formed with recesses and protrusions. CONSTITUTION:The coupling surface of a driving member 11 made of a magnetic material is formed with a multitude of relatively small recesses and protrusions. A driven member 17, provided so as to oppose the coupling surface of the driving member 11 with a small gap, is also made of the magnetic material and the coupling surface thereof is formed with a multitude of recesses and protrusions. The magnetic particles between the coupling surfaces of the driving member 11 and the driven member 17 are magnetized by the excitation of an exciting coil 12 and effect the transmission of the power.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic particle type electromagnetic coupling device, and more particularly to a magnetic particle type electromagnetic coupling device that transmits rotational force (t or torque) in an electromagnetic coupling device using magnetic particles.

As is well known, magnetic particle type electromagnetic coupling devices are used in automobile clutches and the like. This magnetic particle type electromagnetic coupling device transmits rotational force by utilizing sliding friction due to magnetic coupling between the coupling surface and magnetic particles, or between magnetic particles. For this reason, each connecting surface of the magnetic particle type electromagnetic connecting device is coated with surface hardening such as chrome plating to withstand this friction. Furthermore, since the magnetic particles used in the magnetic particle type electromagnetic coupling device require heat resistance and wear resistance, each coupling surface of the magnetic particle type electromagnetic coupling device is coated with a surface tin salt that is close to a mirror finish.

FIG. 1 provides the background of this invention and shows a sectional view of a magnetic particle type electromagnetic coupling device applied to this invention.

FIG. 2 shows an enlarged cross-sectional view of each connecting surface of the 1m.

FIG. 3 shows an enlarged view of the bonding state of the eleventh magnetic particles.

In the configuration, the magnetic particle type electromagnetic coupling device 10 includes a drive member 11, an excitation coil 12, and a bracket (13a, 1).
3b, bearing 14al114b % output shaft 15,
Sealing material 16a116b % Driven member 17,
It is composed of magnetic particles 18 and labyrinses 19a and 19b. The drive member l'l has an annular shape 13b to which power is supplied by a slip ring pusher (not shown) or the like.
It is supported with bolts, etc. bracket l-
The tortoise 13 and 13b are connected to a drive side (not shown) and are rotatably supported by a bearing 14ae141) and an output shaft 15. Bracket 13a1.13
Bearings 14 & 14b on the contact surface between b and output shaft 15
Magnetic particles 18 are located near the bearings 14m and 14b.
A sealing material 16, 16b is provided to prevent the material from entering. Inside the sealing material 16, there are brackets 13m, 1
A driven member 17 fixed to the output shaft 15- is provided with a small gap from the output shaft 3b. In the gap between the driven member 17 and the brackets 13a, 13b, the magnetic particles 18 are held as close as possible to the connection surface between the drive member 11 and the driven member 17, and the magnetic particles 18 are held in the gap between the sealing members 16m, 16b. A labyrinth 191.19b is provided on the side wall of the driven member 17 to reduce intrusion.゛The connecting surfaces of the drive member 17 and the driven member 17, that is, the inner surface 111 of the drive member 11 and the outer surface 171 of the driven member 17, as shown in #2A, have a surface hardening process such as Ichrome plating, which is close to a mirror finish. will be performed.

Further, the outer surface 17'1 of the driven member 17 is provided with V-shaped grooves 172 at intervals in the radial direction, as shown in the second row.

Note that the drive member 11 is provided on the drive side, and the driven member 17 is provided on the side to be driven.

In operation, when the bracket 131.13b coupled to the drive fIA (not shown) rotates, the drive member 11 rotates. Furthermore, when power is supplied to the excitation coil 12 built in the drive member 11, the excitation coil 12
As shown by the dotted line in FIG.
occurs. Therefore, the magnetic particles 18 are magnetized and bonded in a chain between the drive member 11 and the driven member 17. - As a result, the magnetic particles 18 connect the driven member 17 fixed to the output shaft 15 and the drive member 11, and transfer the rotational force of the drive member 11 to the driven member 1.
7 and the output shaft 15 for driving. At this time, since the v-shaped groove 172 is formed on the outer surface 171 of the driven member 17, the inner surface 11 of the drive member 11
1 and the effective connecting surface area of the outer surface 171 of the driven member 17.
The magnetic flux density on the inner surface 111 of the drive member 11
It becomes higher than the magnetic flux density above. For this reason, magnetic particles 1
8 are connected in a chain as shown in FIG. Additionally, the magnetic particles 18 are arranged on the outer surface 171 of the driven member 17.
Since the magnetic resistance of the v-shaped groove portion 172 provided in the groove 11172 is large, the particles do not accumulate in the groove 11172 and remain as a gap. As a result, the magnetic attraction force of the outer surface 171 of the driven member 17 becomes larger than the magnetic attraction force of the inner surface 11-1 of the drive member 11, and the portion where the slip occurs is mainly connected to the inner surface 111 of the drive member 11. Become. Therefore, by providing the groove portion 172, the heat generated by sliding friction is not absorbed into the magnetic particles 18 or into the driven member 17, but is conducted to the outer periphery through the drive member 11. Further, even in the connected state, the V-shaped groove 172 does not collect the magnetic particles 18 and remains a gap, so when the connected state is released, the fate of the magnetic particles 18 is quickly eliminated, and the drive member 11 is removed from the driven member. 17 and the output shaft 15.

On the other hand, when the power supply to the excitation coil 12 is cut off, the magnetic particles 18 release their magnetic attraction force and release the bond between the magnetic particles 18 . Therefore, transmission of rotational force from the drive member 11 to the driven member 17 and output shaft 15 is interrupted. At this time, the drive member 11 and the bracket 13
Since 1L and 13b are rotationally driven, the magnetic particles 18 are pressed onto the inner surface 111 of the drive member 11 by centrifugal force.

As a result, the transmission of rotational force is quickly interrupted along with the aforementioned effect of the V-shaped groove fib 172.

However, in the magnetic particle type electromagnetic coupling device having such a structure, the magnetic absorption force of the outer surface 171 of the driven member 17 is larger than the magnetic attraction force of the inner surface 111 of the drive member 11. surface 111
Sliding friction is generated between the drive member 11 and the magnetic particles 18, and the transmission of rotational force to the driven member 17 and the output shaft 15 is lower than that of other types of coupling devices.

Next, the sliding friction between the magnetic particles and each connecting surface will be explained with reference to 113E.

First, the magnetic particles 18 are j! Assuming that the driven member 17 is spherical and connected in a chain as shown in Figure 3, a radial force Y based on rotational force acts on the outer surface 171 of the driven member 17. 1
The magnetic attraction force between the outer surface 171 of the driven member 17 and the magnetic particles 181 is PQ, the frictional force due to the magnetic attraction PO is PQ, and the friction coefficient between the outer surface 171 of the driven member 17 and the magnetic particles 1881 is PQ. , magnetic particles 18m and magnetic particles 18b
The magnetic attraction force between Pl and the contact point A between the outer surface 171 of the driven member 17 and the magnetic particle 18& and the magnetic particle 1811
The angle that the contact point B of the magnetic particle 18b makes with respect to the axial direction is θl.

100 inside magnetic particle 18m and center 0' of magnetic particle 18b
is an angle θ2 with respect to the axial direction, and r is the radius of the magnetic particle 18. At this time, the force acting on the magnetic particle 1811 in contact with the outer surface 171 of the driven member 17 is as follows. , j The radial frictional force shown in Figure 13 is expressed by equation (1).

RmPlsinθl R,, /A PO p Pg = Plsinθ1−・------(11) Also, the axial magnetic attraction force PO shown in FIG. 3 is expressed by formula (2)
It is expressed as

POtomi P1 cos 01 - One song... (2) Therefore, the force acting on the magnetic particles 18a (the balance of forces is expressed by equation (1) and equation (
2), formula (3) is obtained.

p Nl 凰! lθl −·−(31) Next, the moment at the contact point B between the magnetic particles 18a and the magnetic particles 18b is expressed by equation (4).

P□ rlinθ2 W Rr Cl+c Osθ2)
m p P Q r (1+C0802) Also, the formula (3
) and equation (4), the relationship between angle θl and angle θ2 is expressed as equation (5
).

Note that the relationships among equations (3), (4), and (5) are the same for the inner surface ill of the drive member 110. Furthermore, considering the magnetic particle 18c, in this case, the magnetic attraction force P along the angle θl with respect to the axial direction
It will be balanced by the power of I. This means that magnetic particles 18
The same applies to the magnetic particles after b, and magnetic particle 18
are connected in a chain with an inclination of angle θl, and Pls
A frictional force of inθ1mpPQ acts between the magnetic particles 18 (here, the inner surface 111 of the drive member 11
:&t and outside NJili171 of driven member 17
The radial force F based on the rotational force is expressed by equation (6),
It is determined by the magnetic attraction force PO and the friction coefficient P.

That is, the magnetic particles 18 connected in a chain form are cut at the contact points between the magnetic particles, the contact points between each connecting surface and the magnetic particles, or at a portion where the magnetic attraction force is small. As a result, the cutting or sliding of the magnetic particles 18 bonded in a chain is prevented from occurring on the inner surface 111 of the drive member 11 and the outer surface 1 of the driven member 17, which are mirror-finished.
Since the coefficient of friction between the magnetic particles 71 is approximately 0.15 to 0.2, which is smaller than the coefficient of friction between the magnetic particles 18, it is likely to occur on the inner surface 111 of the drive member 11, where the magnetic attraction force is small (
Become.

Therefore, as mentioned above, the magnetic particle type electromagnetic coupling device has each coupling having heat resistance and wear resistance that can withstand the sliding friction between each coupling surface and the magnetic particles or between the magnetic particles. The disadvantage is that surfaces and magnetic particles are required, which increases the cost, and - because of this friction, the transmission of rotational forces is low compared to other types of coupling devices.

Therefore, an object of the present invention is to provide a magnetic particle type electromagnetic coupling device that is inexpensive, durable, can efficiently transmit rotational force, and has a large rotational force.

In summary, the present invention is such that an etching process is used to form irregularities of such a degree that magnetic particles fit into each connecting surface.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 shows an enlarged view of the bonding state of magnetic particles on each coupling surface of a magnetic particle type electromagnetic coupling device according to an embodiment of the present invention. The corresponding parts are shown. In the configuration, the embodiment of ξ differs from FIGS. 111 to 3 in that the first coupling portion is
The outer surface 171 of the driven member 17, which is an example of the connecting portion between the magnetic particles 11 and j12, is etched to form an 11 degree concavity and convexity 41 into which the magnetic particles 18 fit. That is, the inner surface 111 of the drive member 110 and the outer surface 171 of the driven member 17 are first cleaned and degreased, and then a corrosion-resistant resist film is applied in a predetermined pattern by printing or other methods and dried.

Thereafter, the inner surface m1ld of the drive member 11 and the outer surface 171 of the driven member 17 are immersed in an etching solution such as ferric chloride or etching solution such as ferric chloride.
Etching treatment is performed by spraying. At this time, the back of the floor of the unevenness 41 formed on the inner surface 1ull of the drive member 11 and the outer surface 1711 of the driven member 17 is 1 m of etching #l & field time!
A predetermined depth is selected by i. Then, the inner surface 111J5 of the drive member 11 and the driven member 1
The resist film is removed from the outer surface 171 of 7 by a resist film removing liquid, and the process such as washing with water and drying is performed to form irregularities 41 regularly or irregularly.

Next, the sliding friction between the magnetic particles and each connecting surface of this embodiment will be explained with reference to FIG. Note that the operation of the magnetic particle type electromagnetic coupling device of this embodiment is the same as that of the conventional magnetic particle type electromagnetic coupling device except for the shape of each coupling surface and the bonding state of the magnetic particles, so a description thereof will be omitted.

As shown in FIG. 4, the magnetic particles 18 are sandwiched between the concavities and convexities 41 corresponding to the dimensions of the magnetic particles 18 on each connecting surface, and are fixed to each connecting surface, so that they are aligned in a straight line passing through the center of the magnetic particles 18. Combine in a chain. At this time, the force acting on the magnetic particles 181 in contact with the outer surface 171 of the driven member 17 is expressed by No. (7) and Equation (87).

F −PI sin el ”== (7) PO difficult P
4 cos θ1 ----------8) Here, the area perpendicular to the axial direction corresponding to the magnetic particle 181I is 5. Permeability is P. , when the gravitational acceleration is g, the axial magnetic attractive force Px generated by the perpendicular magnetic flux Φ passing through this area S is expressed by equation (9). Since the surface on which the magnetic attraction force Pl acts is inclined by an angle wlh with respect to the axial direction, that is, the area 8, the magnetic attraction force Pl is expressed as follows.

As a result, the relationship between equation (9) and equation αG is as follows.

p l m Px cosθ1 -------- dl
l Also, the radial force F based on the rotational force on the outer surface 171 of the driven member 17 is expressed as Equation (7), Equation (8: I%) and Equation (2), and is maximum when the angle θl is 45[ becomes.

J' wm Px Cogθ1 sinθl At this time,
The magnetic attraction force P6 is expressed by equation 0.

The relationships expressed by equations (7) to (2) also apply to the inner surface Ill of the drive member 11. Therefore, the following can be understood from the equation a3$ and the equation (to).

That is, from the drive member 11 to the driven member 17
When power is supplied to the excitation coil 12 in a state where the rotational force is not exclusively transmitted to the output shaft 15, the magnetic particles 18 become uneven 41.
The magnetic particles 18 are arranged in a line along the axial direction while being sandwiched between them.

After that, when the rotational force is transmitted, the arrangement between the magnetic particles 18 becomes similar due to the radial force F based on the rotational force, and formula (2)
The angle represented by 017) is connected in a chain with an inclination. At this time, the change in the arrangement of the magnetic particles 18 is
It is caused by sliding or rolling between 8 and is expressed by the formula (2
), it can be understood that the friction coefficient is not the cause. Also,
The change in the arrangement of the magnetic particles 18 due to the contact between the magnetic particles 18 and the convex magnetic particles 18 on each connecting surface is determined by the magnetic attraction force having an angle θ1 from equations (7) to 0. Caused by Pl. When the angle θl becomes 45 degrees, the force applied in the radial direction (i.e., rotational force) - PPO
'v(0,15~0.2)PX Yorika utJ large fk<
fjru. As a result, the transmission of the rotational force from the drive member 11 to the driven member 17 and the output shaft 15 is achieved by the relative rotation of the conventional connecting blades and the magnetic particles 18, or by the sliding between the magnetic particles 18. , the angle θl
Magnetic particles 18 bound together by magnetic attraction P1 with
The arrangement of the magnetic particles changes and rotates as the space increases and separates. This jar, magnetic particles 18 being separated
There is no frictional resistance against the magnetic attraction force between them.

Therefore, the magnetic particle type electromagnetic coupling device of this embodiment can transmit rotation and power more efficiently than the conventional magnetic particle type electromagnetic coupling device.

Note that in the above-described embodiment, a case has been described in which the rotational force of the drive member 11 is transmitted to the driven member 17 and the output shaft 15 to act as a clutch, but the present invention is not limited to this, and either one of the drive member 11 or the driven member 17 You can also fix it and use it as a play cow. Also,
In the embodiment described above, the inner surface 111 of the drive member 11
# and irregularities 41 on the outer surface 171 of the driven member 17
Although the case where the unevenness is formed by etching has been described, the present invention is not limited to this, and other methods may be used to form the unevenness.

As described above, according to the present invention, each connecting surface of the magnetic particle type electromagnetic connecting device is formed with unevenness, thereby eliminating the need for surface hardening such as chrome plating, mirror finishing, etc., and it can be formed at low cost and has high durability. The rotational force can be transmitted efficiently and a large rotational force can be obtained. Also, by forming the unevenness by etching II and dovetailing, unique effects such as regular unevenness are produced. In addition, according to the invention of ξ, if it is necessary to form irregularities regularly by etching tin salt, it can be easily formed.

[Brief explanation of the drawing]

No. 15A serves as the background of this invention and shows a sectional view of a magnetic particle type electromagnetic coupling device applied to this invention. No. 2- shows an enlarged sectional view of the connecting surface of the first decoy. FIG. 3 shows an enlarged view of the bonding state of the magnetic particles shown in FIG. Figure Ws4 shows an enlarged view of the bonding state of magnetic particles on each coupling surface of the magnetic particle type electromagnetic coupling device according to an embodiment of the invention of B. In the figure, lO is a magnetic particle type electromagnetic coupling device, 11 is a drive member, 12 is an excitation coil, 131 and 13b
14 is a bracket, 14 is a turtle, 14b is a ball bearing, 15 is an output shaft, 17 is a driven member, and 18 is a magnetic particle. Substitute person Kuzuno Value - (1 other person) Base 1 concave /71 /7? ／；／昂：三謬

Claims (4)

[Claims] (1) A rotatable first connecting part made of a magnetic material and having a large number of relatively small uneven parts formed on the connecting surface. A rotatable first connecting part. A rotatable first connecting part. A rotatable first connecting part. A rotatable first connecting part. The j! a second connecting part to which the rotational force of the first connecting part is transmitted and rotated; a second connecting part is enclosed between the first connecting part and the second connecting part and is magnetized to magnetically rotate the second connecting part; A magnetic particle type electromagnetic coupling device comprising magnetic particles that transmit the rotational force of one coupling part to the second coupling part, and an excitation coil that magnetizes the magnetic particles by being selectively excited. (2) The uneven portion is formed in a relatively small shape that is suitable for the magnetic particles to fit into.
The magnetic particle type electromagnetic coupling device described in item 13. (3) The magnetic particle type electromagnetic coupling device according to claim (1) or (2), wherein the uneven portion is formed by a non-etching process. (4) The etching plate is prepared by cleaning and degreasing the connecting surfaces of the first and second connecting portions, applying a corrosion-resistant resist film in a predetermined pattern by a printing method, and drying it.
! A magnetic particle type electromagnetic coupling device according to claim 3, which is processed by immersion in a diiron etching solution.