JPS63246520A - Powder clutch - Google Patents

Abstract

PURPOSE:To prevent magnetic powder from leaking out of a powder gap by forming a friction face which is brought into contact with said magnetic powder with a hard magnetic material and allowing magnetism to remain on said friction face even when electromagnetic force is deenergized. CONSTITUTION:When electrification to an exciting coil 6 is stopped, since cementation is given to the friction faces 5a, 10a on the outer peripheral parts of first and second engaging main bodies 5, 10 and the friction faces 22a, 22b on the outer peripheral parts of a third engaging main body 20, the density of remnant magnetism is increased. Thereby, magnetic power is attracted to the friction faces, effectively preventing the movement of the magnetic powder. Hence, even when the electrification to the exciting coil is stopped, the leakage of magnetic powder can be prevented by the remnant magnetism on the friction faces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a powder clutch used in a driving force transmission means of a vehicle or the like.

[Prior Art] Conventionally, as this type of powder clutch, for example, a third
There is one shown in the figure. That is, 100 is a drive shaft, and a first connecting body 105 is connected to this drive shaft 100 via a flywheel 103 so as to rotate integrally.
A cylindrical second connecting body 109 integrally connected via a ring-shaped connecting member 107 is fitted into the inner periphery of the first connecting body 105 . These connecting bodies 105 and 109 are made of low carbon steel (JIS standard: 510
) is formed from. First and second connecting entities 105.1
09 is a cylindrical third shaft connected to the driven shaft 111.
The outer peripheral part of the connecting body 113 is inserted, and the first and second
Powder gaps 124a and 124b are formed. Labyrinths 150 are provided on both sides of the first and second powder gaps 124a, 124b in order to prevent magnetic particles from leaking from the powder gaps.

In the above configuration, the clutch connection action is performed by applying current to the excitation coil 106 through the slip ring 138 and the wiring 139 to bias it. Then, magnetic flux is generated by excitation of the excitation coil 106, and the first . The magnetic particles placed in the second powder gaps 124a and 124b form a chain-like connector, and due to the frictional force and electromagnetic coupling force between the magnetic particles, the first powder, which is the main link on the drive side, is connected to the second powder gap 124a, 124b. Second consolidated entity 10
5° 109 and the third connecting body 11 which is the driven side connecting body
3 are connected to perform power transmission.

Incidentally, as a conventional technique similar to this type of powder clutch, the one disclosed in Japanese Patent Application Laid-Open No. 58-42839 is known.

[Problems to be Solved by the Invention] By the way, in the conventional clutch, when the first connecting body 105 rotates in the clutch disengaged state, the magnetic particles in the first outer powder gap 124a are moved by the centrifugal force caused by the rotation. Although the magnetic particles in the second powder gap 124b on the inner circumferential side are pressed against and deeply supported by the inner peripheral friction surface of the connecting body 105, the magnetic particles are transferred from the second connecting body 124b to the labyrinth 150.
The amount of magnetic particles in the second powder gap 124b may decrease as the magnetic particles move along the first powder gap 124a. As a result, the clutch power transmission performance becomes unstable and torque controllability deteriorates, and the first powder gap 1
Drag torque increases due to excessive magnetic particles in 24a,
There was a problem in that the clutch disengagement characteristics deteriorated and the synchronizer ring of the manual transmission wore out.

Furthermore, the slippage of the clutch described above may cause the clutch itself to overheat, causing damage to the insulating material such as the coil covering member.

As a solution to this problem, increasing the number of labyrinths 150 or narrowing the gap between the opposing members has been considered, but this method requires a large number of parts and also
Manufacturing requires precise dimensional tolerances, leading to increased costs.

[Means for Solving the Problems] The present invention, which has been made to solve the above problems, has a cylindrical drive-side connection main body integrally rotatably connected to the drive shaft, and a cylindrical drive-side connection main body integrally connected to the driven shaft. and a driven side connecting body which is rotatably connected to each other and is loosely fitted to the inner periphery or outer periphery of the driving side connecting body with a predetermined gap therebetween, and the driving side connecting body and the driven side connecting body are magnetically connected. A cylindrical powder gap containing magnetic powder is formed between the mutually opposing friction surfaces of both connecting bodies, and an electromagnetic force is applied between the driving side and driven side connecting bodies through the magnetic powder. In the powder clutch, the driving force of the driving shaft is transmitted to the driven shaft by connecting the driving side connecting main body and the driven side connecting main body by force, and at least one surface of the plurality of friction surfaces is connected to the driving member. Alternatively, it is characterized by being formed of a hard magnetic material having a larger coercive force than the inside of the driven member.

The friction surface can be made of a material with a large holding force, for example, by surface-treating the connecting body made of a soft magnetic material by carburizing, or by pasting a member made of a hard magnetic material on the inner or outer periphery of the connecting body. can be formed.

Types of powder clutches include single-gap powder clutches, which have a single powder gap between the driving-side connecting body and the driven-side connecting body, and multi-gap powder clutches, which have multiple powder gaps. It's okay.

[Function] The Bauder clutch according to the present invention is configured such that the driving side connecting body and the driven side connecting body are connected and disconnected by electromagnetic force applied via magnetic particles between the driving side connecting body and the driven side connecting body. Ru.

Roughly speaking, the friction surface that comes into contact with the magnetic particles is made of a hard magnetic material with a large coercive force. As a result, even if the electromagnetic force is deenergized, magnetism remains on the friction surface and magnetic particles are attracted, thereby preventing leakage from the powder gap. Furthermore, since only the friction surface is made of a hard magnetic material and the connecting body itself is made of a soft magnetic material, a decrease in magnetic permeability does not occur.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a drive shaft, and a flywheel 3 is attached to the drive shaft 1 via bolts 2, and a first connecting body 5 is further attached via bolts (not shown). This first connection main body 5 has annular divided members 5A and 5B.
An excitation coil 6 is housed inside, and a non-magnetic ring 7 made of a non-magnetic material is attached to the inner periphery. The first connecting body 5 is made of 5IO (JIS standard) low carbon steel, and its inner peripheral friction surface 5a (see FIG. 2) is carburized. Carburizing treatment can be carried out, for example, by applying a carburization inhibitor to the area where carburization is not to be performed, heating it to 800°C to 875°C in a carbon oxide or hydrocarbon atmosphere, and increasing the carbon content to 0.2% by weight or more. ing.

A second connecting body 10 having a friction surface 10a is disposed on the inner peripheral side of the first connecting body 5, and is connected to the first connecting body 5 and a connecting member 12 made of a non-magnetic material.4.1
They are connected via 3.

This second connected body 10 is connected to S1 like the first connected living body 5.
0 and a friction surface 10 on its outer periphery. A is also carburized in the same way as the friction surface 5a.

The connecting member 12 is made of SUS material such as a stainless steel chain net or a stainless steel sintered body. $22 Connector 5,
10, and the outer peripheral portion 12a of the first connecting body 5 is formed of a material having a lower thermal conductivity than that of the central portion 12.
b is positioned by the stepped portion 10b of the second connecting main body 10, and one side of the bearing 15 is held by the inner peripheral portion 12c.

The bearing 15 is positioned together with the inner peripheral part 12c by the retainer 17 and the snap ring, and rotates around the outer periphery of the cylindrical part 20a of the third connecting body 20 and the second connecting body 10 via the connecting member 12. I freely support it.

The outer peripheral portion 20b of the third connecting main body 20 is connected to the first connecting body 20. The first connecting body is inserted between the second connecting bodies 5 and 10 and has magnetic powder (not shown) arranged thereon. Second powder gap 24a, 24
b, and constitutes a so-called multi-gap powder clutch. As shown in FIG. 2, the outer circumferential portion 20b of the third connection main body includes an annular first magnetic path forming member 21a and a second magnetic path forming member 21b, and both magnetic path forming members 21a,
A magnetic path blocking member 21c positioned by a cut portion is interposed between 21b and they are welded and joined. The friction surfaces 22a and 22b of the outer peripheral portion 20b of the third connecting body are also carburized in the same manner as the first and second connecting bodies 5.10. In addition,
1st. For example, the second magnetic path forming members 21a and 21b are 9
It may also be made of high carbon steel such as No. 45.

The bottomed portion 20C on the left side in the drawing of the third connecting main body 20 is a bottle 25. Connecting member 26. It is connected to a cylindrical hub portion 30 via a rubber damper mechanism, and a driven shaft 32 is spline-fitted to the inner periphery of the hub portion 30. A dustproof cover member 35 made of a non-magnetic material made of aluminum casting is arranged on the outer periphery of the driven shaft 32.
The first
It is attached to the connecting body 5, and a slip ring 38 is attached to the outer periphery of the cylindrical portion 35b, so that power is supplied to the excitation coil 6 via wiring 39.

Above 1. A labyrinth 50 is provided to prevent the magnetic particles placed in the second powder gaps 24a, 24b from leaking out of the powder gaps.

Attached to the second connection main body 10 or to the retainer 17,
A wing 62 is erected, and a through hole 63 is formed adjacent to 3E62. A through hole 65 is also formed in the connecting member 12 in communication with this through hole 63, and a through hole 65 is also formed in the connecting member 12, and a communicating hole 68 is formed in the inner peripheral portion 10c of the second connecting main body 10 and the communicating hole 68 formed in the cylindrical portion 20a. is formed.

Note that 100 is a clutch housing.

Next, the operation of the above configuration will be explained.

First, the connection action of the clutch is performed by the slip ring 38.
This is done by applying current to the excitation coil 6 through the wiring 39 to energize it. When the excitation coil 6 is energized, a magnetic flux as shown by a broken line S is generated. Due to the generation of this magnetic flux, the first. The magnetic particles arranged in the second powder caps 24a and 24b are connected to each other in a chain shape, and due to the frictional force and N magnetic coupling force between the magnetic particles, the first and second connecting bodies 5, which are the driving side members, , 10 and the third member which is the driven side member.
The connecting body 20 is connected to perform power transmission. Therefore, by controlling the current to the excitation coil 6 intermittently, the clutch is engaged and engaged.

At this time, even if the energization to the excitation coil 6 is stopped, the first .
The friction surfaces 5a, 10a of the second connecting bodies 5, 10 and the third
outer periphery gt of the bundle 20 (friction surfaces 22a, 2 of 20c)
Since 2b is carburized, the residual magnetic density is high. Therefore, the magnetic particles are attracted to the friction surface and are transferred from the second powder gap 24b to the second powder gap 24a, or from the first powder gap 24b to the second powder gap 24a. This effectively prevents the powder from moving toward the inner circumferential side of the clutch from the second powder gaps 24a, 24b. Moreover, the first. Second connected entity 5, 10 and third connected entity 20
The friction surfaces 5a, 10a, 22a are made of a material with high magnetic permeability such as S10.

Since only 22b is carburized, the clutch can be engaged and engaged efficiently without causing a decrease in magnetic permeability.

Hereinafter, due to the magnetic powder leakage prevention effect due to the high residual magnetism of the friction surface as described above, the following effects are achieved.

(1) Since movement of magnetic particles from the second powder gap 24b to the first powder gap 24a is prevented, there is no increase in drag torque. This makes it possible to reduce wear on the synchronizer ring of the transmission connected to the clutch.

(2) Since the slippage that occurs between the driving side and the driven side that occurs due to the decrease in the amount of magnetic particles is eliminated, it is possible to prevent filtration droplets and seizures due to slipping, which reduces the loss of insulating materials such as the outer cover of the wiring +14 It can be prevented.

(3) In addition, compared to chromium plating the friction surface to improve its wear resistance, carburizing can improve wear resistance in a shorter time and at a lower cost. Moreover, unlike chrome plating, it is not a non-magnetic material and does not cause a significant decrease in magnetic permeability, so even a small latch can provide a large transmission force.

(4) Sufficient leakage of magnetic particles can be prevented without having to provide multiple labyrinths 50. Therefore, the clutch can be easily made smaller and lighter by reducing the number of labyrinths 50.

(5) First. Since the magnetic powder leaking from the second powder gaps 24a, 24b does not reach the bearing 15 and damage the bearing 15, maintenance can be simplified.

(6) Since the magnetic particles move only slightly when the excitation coil 6 is switched between energization and de-energization, responsiveness and torque transmission characteristics become faster, and sluggishness at the time of starting is reduced.

[Effects of the Invention] As explained above, according to the present invention, when the excitation coil is de-energized, residual magnetism on the friction surface can prevent leakage of the clutch. Intermittent characteristics can be improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the main parts of a multi-gap powder clutch according to an embodiment of the present invention, Fig. 2 is a sectional view showing a multi-gap powder clutch of the same embodiment, and Fig. 3 is a conventional powder clutch. FIG. 5...First connecting entity 10...Second connecting entity 20...Third connecting entity

Claims (1)

[Scope of Claims] 1. A cylindrical driving-side connecting body that is integrally and rotatably connected to the drive shaft, and a cylindrical driving-side connecting body that is integrally and rotatably connected to the driven shaft, and that includes an inner periphery of the driving-side connecting body or The driving side connecting body and the driven side connecting body are loosely fitted on the outer periphery with a predetermined gap, and the driving side connecting body and the driven side connecting body are formed of a magnetic material, and there is a gap between the mutually opposing friction surfaces of both the connecting bodies. A cylindrical powder gap having magnetic powder is formed, and the driving side connecting body and the driven side connecting body are connected by urging electromagnetic force through the magnetic powder between the driving side connecting body and the driven side connecting body. In the powder clutch that transmits the driving force of the drive shaft to the driven shaft, at least one of the plurality of friction surfaces is formed of a hard magnetic material having a larger coercive force than the inside of the driving member or the driven member. A powder clutch characterized by this.