JPS6344972B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention is an electromagnetic coupling device such as an electromagnetic clutch that can freely transmit torque from an input rotating member to an output rotating member, and uses an armature divided into a plurality of annular pieces with different diameters. This invention relates to a leaf spring for an electromagnetic coupling device.

An electromagnetic coupling device that transmits torque from an input rotating member to an output rotating member by magnetically adsorbing an armature attached to one of the input rotating member and the output rotating member via a leaf spring to the other. A known technique is to divide the two members into annular pieces of different diameters and to provide a time difference in the magnetic adsorption operations of these annular pieces of different diameters, thereby avoiding a sudden rise in torque and connecting the two members in a cushioning manner. (For example, see Utility Model Publication No. 47-22293).

In this case, the leaf springs that support the plurality of annular pieces with different diameters each have one end fixed to one rotating member and the other end fixed to the plurality of concentrically arranged annular pieces of different diameters, so the orientation of the leaf springs is , the direction intersects with the rotational direction of the rotating member, and when each of the different diameter annular pieces is magnetically attracted to the other rotating member, twisting occurs,
Problems were that the torque build-up was not smooth and that the number of parts and installation man-hours were large, making it uneconomical.

An object of the present invention is to provide a leaf spring for an electromagnetic coupling device which solves the above-mentioned problems, and includes branches facing each of the concentric annular pieces of an armature divided into a plurality of concentric annular pieces, preferably an arcuate branch. The distal end of each branch is fixed to a concentric annular piece located at a corresponding position, while the base of each branch is fixed to an armature support member, and The feature is that the spring load is different.

Next, the leaf spring of the present invention will be described by way of examples with reference to the drawings.

Fig. 1 shows a front view of a first embodiment of the leaf spring of the present invention, Fig. 2 shows a front view of a state in which it is attached to an armature, and Fig. 3 shows a double plate spring as an example of an electromagnetic coupling device. The state of attachment to the pulley-type electromagnetic clutch is shown in a longitudinal sectional side view, and FIG. 4 is a partially cutaway view in the direction of the arrow in FIG. As shown in the drawings, the leaf spring 1 of the first embodiment has an armature A divided into three concentric annular pieces 2, 3, and 4, with arcuate curved branches 1A facing each of the concentric annular pieces.
1B and 1C, and these branches are integrated at the base 1D.

The branch portion 1A of the leaf spring 1 is connected to the concentric annular piece 2, and the branch portions 1B and 1C are connected to the concentric annular pieces 3 and 4, respectively.
The tips are fixed to corresponding concentric annular pieces.

The concentric annular pieces 2, 3, and 4 connected to each other by the leaf spring 1 are supported by the input pulley 5 by fixing the base 1D of the leaf spring to the input pulley 5 as an armature support member.

The leaf spring 1 is normally used with three leaf springs spaced at equal angles of 120 degrees and oriented in the same direction.

The input pulley 5 has a bolt 9 and nuts 10, 10 attached to a dish-shaped joint 8 that rotates integrally with the input shaft 7 of the device 6.
, and is supported via a bearing 12 on a boss portion 11 of a device 6 surrounding the input shaft 7 so as to be freely rotatable.

The joint 8 is non-circularly fitted to the input shaft 7 side, and is movable in the axial direction, but rotates integrally with the input shaft 7.

An output pulley 14 is supported on the boss portion 11 via a bearing 13 so as to be freely rotatable.

The input pulley 5 and the output pulley 14 are kept facing each other with a gap between them by a spacer 15 between the bearings 12 and 13, and an annular field core 17 is exposed in the annular groove 16 of the output pulley 14.

The field core 17 has a built-in electromagnetic coil 18, and when a voltage is applied to this electromagnetic coil, the generated magnetic flux snakes from the output pulley 14 to each of the concentric annular pieces 2, 3, and 4 of the armature A. (commonly known as triple flux).

Concentric annular pieces 2, 3 of the energized armature A,
4 are magnetically attracted to the output pulley 14 in the order from the longest branch of the leaf spring 1 to the shortest branch.

Note that reference numerals 19A, 19B, and 19C in the figure indicate arc-shaped holes for detouring magnetic flux in an intermittent arrangement, which are formed in the output pulley 14 in correspondence with the respective concentric annular pieces 2, 3, and 4 of the armature A. Reference numerals 20 and 21 denote rubber stoppers, which buffer the concentric annular pieces 2, 3, and 4 of the armature A, which are strongly returned toward the input pulley 5 by the action of the leaf spring 1 during demagnetization. 2
2, 22' are rivet holes provided in the leaf spring 1, 23,
23' indicates a rivet.

The leaf spring 1 of the present invention configured as described above enables the time difference magnetic attraction of the concentric annular pieces 2, 3, and 4,
Avoids sudden torque rises and enables buffered torque transmission.

When the leaf spring 1 of the present invention is used in the electromagnetic clutch shown in FIGS. 3 and 4, the armature A rotates together with the input pulley 5 to which torque is transmitted from an external power source via a belt (not shown). Concentric annular pieces 2, 3, and 4 are supported on an input pulley 5 so as to be movable in the axial direction.

Concentric annular pieces 2, 3, 4 are connected to branches 1A, 1B, 1C
The leaf springs 1 attached to the concentric annular pieces 2,
3 and 4 become one of the torque transmission members between the input pulley 5 and the output pulley 14 by being magnetically attracted to the output pulley 14, but the branch parts 1A, 1B, 1
Since C is curved in an arc facing the direction of rotation,
There is no risk of twisting.

The leaf spring 1' of the second embodiment shown in FIG. 5 is an example in which the lengths of the branch parts 1'A, 1'B, and 1'C branched from the base 1'D become larger as they reach the inside. And,
In this case, in the armature A, the concentric annular piece 4 with the smallest diameter is first magnetically attracted to the output pulley 14, then the concentric annular piece 3 is magnetically attracted, and finally the concentric annular piece 2 is magnetically attracted.

In both of the above two embodiments, the spring load is different depending on the length of the branch, but it is possible to keep the length the same and vary the plate thickness (for example, by stacking the required number of plates one after another). The spring load may be varied by changing the width of the portion.

As is clear from the above description, the leaf spring of the present invention is capable of magnetically attracting each of the concentric annular pieces of the armature divided into concentric annular pieces in a predetermined order, so that sudden torque in an electromagnetic coupling device can be avoided. Not only can it prevent the rise of the temperature, but it also has excellent industrial effects, such as reducing the number of assembly steps because only a small number of them need to be used.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a first embodiment of the leaf spring of this invention, Fig. 2 is a front view showing how it is attached to an armature, and Fig. 3 is an example of an electromagnetic coupling device using the leaf spring of this invention. FIG. 4 is a view taken in the direction of the arrow in FIG. 3, and FIG. 5 is a front view showing the second embodiment. In the drawings, 1, 1'...the leaf spring of this invention,
1A, 1'A, 1B, 1'B, 1C, 1'C... Branch, 1D, 1'D... Base, 2, 3, 4... Concentric annular piece, 5... Input pulley, 6... ...Equipment, 7...
Input shaft, 8...Joint, 12, 13...Bearing, 14...Output pulley, 15...Spacer, 1
7... Field core, 18... Electromagnetic coil, A
... Armature.

Claims (1)

[Claims] 1. An electromagnetic device in which an armature divided into a plurality of concentric annular pieces can be magnetically attracted to a rotating member or a stationary member arranged on the same axis, and the armature is movably supported in the axial direction by an armature support member arranged on the same axis. In leaf springs for coupling devices,
A concentric annular piece consisting of a base fixed to the armature support member, and arcuate curved branches branching from the base and facing each of the concentric annular pieces, with the tip of each branch at a position facing each other. 1. A leaf spring for an electromagnetic coupling device, characterized in that the leaf spring is fixed to each branch part, and the spring loads of each branch part are different.