JPS6222669Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an electromagnetic spring clutch. An electromagnetic spring clutch is a device that transmits the rotational torque of an input rotor to an output rotor by the winding force of a coil spring, and is widely used in automobiles, etc., to drive the compressor of a car air conditioner with the output of the engine.

By the way, a conventional electromagnetic spring clutch generally has an input rotor 1, a bearing 2 attached to the input rotor 1, and a compressor rotatably attached to the input rotor 1 via the bearing 2, as shown in FIG. output rotor 3,
A coil spring 4 is installed across the output rotor 3 and the input rotor 1, and contracts in diameter when a winding force is applied to integrally connect the output rotor 3 and the input rotor 1.
, an armature 5 attached to one end of the coil spring 4, and an electromagnetic coil 6 that attracts the armature 5. When a voltage is applied to the electromagnetic coil 6, the armature 5 attracts the armature attraction surface provided on the input rotor 1. 1a, the armature 5 rotates together with the input rotor 1. This applies a winding force to the coil spring 4, and the output rotor 3 and input rotor 1 are integrally connected. Rotational torque is output from rotor 3
It is now being transmitted to However, an electromagnetic spring clutch with such a configuration has an electromagnetic coil 6.
When a voltage is applied to the armature 5, the armature 5 moves rapidly together with the input rotor 1 and rapidly tightens the coil spring 4, causing the coil spring 4 to hit the input rotor 1 and the output rotor 3, producing a high-pitched sound, or When an electromagnetic spring clutch with a similar configuration is used to transmit torque to a car cooler compressor (not shown), the compressor experiences large torque fluctuations due to load fluctuations in the refrigeration cycle, and this causes torque fluctuations to the output rotor 3. If the coil spring 4 becomes loose,
Alternatively, there was a problem that the windings were tightened more strongly and a so-called creaking sound was produced.

Therefore, as shown in Fig. 2, a sub-armature 5' is attached to the output rotor 3 so as to be movable in the axial direction.
The armature 5 is assembled to the sub-armature 5' so as to be relatively displaceable in the circumferential direction, and both the armature 5 and the sub-armature 5' are energized by applying voltage to the electromagnetic coil 6, and the input rotor of the sub-armature 5' is By moving the armature 5 at low speed in the rotational direction of the input rotor 1 due to contact resistance with the coil spring 4 and gradually tightening the coil spring 4, the coil spring 4 hits the input rotor 1 and the output rotor 3. The coil spring 4 can be prevented from becoming loose by absorbing the torque fluctuation of the output rotor 3 caused by the compressor torque fluctuation by the suction force on the suction surface 1a of the sub-armature 5'. Electromagnetic spring clutches were also developed to prevent the squeaking noise caused by stronger tightening.

However, in the conventional electromagnetic spring clutch of this type, the gap _g1 between the armature 5 and the armature suction surface 1a and the gap g1 between the sub-armature 5' and the armature suction surface _1a are uniformly formed, as shown in FIG. Because the electromagnetic coil 7
When a voltage is applied to the armature 5, the armature 5 and the sub-armature 5' are simultaneously attracted to the armature suction surface 1a, and the sub-armature 5' is attracted to the armature 5.
Until the coil spring 4 is wound tightly by the coil spring 4 and the input rotor 1 and output rotor 3 rotate together, the armature is in a so-called sliding state on the suction surface 1a, resulting in severe wear and loss of durability. It was hot.

In this invention, the armature and the sub-armature are provided with overlapping parts that overlap each other, and the joining surfaces of these overlapping parts are inclined in the circumferential direction, so that the armature is moved to the armature adsorption surface by the cam action of the overlapping parts having the inclined joining surfaces. The above-mentioned drawbacks of the conventional art are solved by adopting a structure in which the sub-armature is attracted to the armature suction surface after the coil spring is wound and tightened.

Next, an embodiment of the present invention will be described based on the drawings from FIG. 3 onwards. 1 is an input rotor. The input rotor 1 is provided with an armature suction surface 1a and a cylindrical boss portion 1b, and a pulley 1c is provided on the outer peripheral surface of the input rotor 1. (omitted). 2
is a bearing attached to the input rotor 1. 3 is an output rotor which is rotatably attached to the input rotor and the compressor. The output rotor 3 has a hub portion 3a having an outer peripheral surface having approximately the same diameter as the outer peripheral surface of the boss portion 1b of the input rotor 1, and a spring cover 3c fixed to the side surface of the hub portion 3a with screws 3b or the like. are doing. 4 is output rotor 3
This coil spring is installed between the output rotor 3 and the input rotor 1, and contracts in diameter when a winding force is applied to integrally connect the output rotor 3 and the input rotor 1. The coil spring 4 is attached to the outer circumferential surface of the boss portion 1b of the input rotor 1 and the outer circumferential surface of the hub portion 3a of the output rotor 3.
It is loosely fitted so as to straddle both, and its one end side 4a is inserted and fixed into a spring end receiving recess 3d provided in the hub portion 3a of the output rotor 3, and the other end side is a so-called free end. 4b, and when a winding force is applied to the free end 4b, the diameter is reduced and the input rotor 1
The input rotor 1 and the output rotor 3 are integrally connected by tightening the boss portion 1b of the input rotor 1 and the hub portion 3a of the output rotor 3.

5 is an armature that is locked to the free end 4b of the coil spring 4. The armature 5
has a diameter slightly larger than the diameter of the boss portion 1b of the input rotor 1, and is formed in a ring shape at a predetermined location on the inner circumferential surface in a recess 5a for receiving the spring end;
It is rotatably inserted between the armature suction surface 1a of the input rotor 1 and the spring cover 3c of the output rotor 3. By inserting the free end 4b into the recess 5a, the armature 5 is locked to one end side of the coil spring 4, and the axial contraction force of the coil spring 4 causes the armature 5 and the armature suction surface 1a to The gap _g1 between the two is maintained at a predetermined value. 5' is a sub-armature which is attached to the output rotor 3 so as to be movable in the axial direction, similarly to the conventional sub-armature shown in FIG. 2, and which is movable relative to the armature 5 in the circumferential direction. The sub armature 5' is armature 5.
It is formed into a ring shape whose inner diameter is slightly larger than the outer diameter of the armature 5, and is arranged on the outer circumference of the armature 5. Reference numeral 6 denotes an electromagnetic coil that attracts the armature 5 and sub-armature 5' to the armature attraction surface 1a. The electromagnetic coil 6 is disposed on the side opposite to the armature attracting surface 1a, and when a voltage is applied, it generates magnetic flux, and the armature 5 and sub-armature 5' are excited by the magnetic flux. Reference numerals 7 and 8 are overlapping parts provided in the armature 5 and the sub-armature 5' in order to attract the sub-armature 5' to the armature suction surface 1a when the coil spring 4 is completely wound by the armature 5. These polymerized parts 7
and 8 are formed protrudingly on the inner circumferential surface of the armature 5 and the outer circumferential surface of the sub-armature 5', respectively, as shown in FIGS. 5 and 6, so that they overlap each other and their joint surfaces 9 is an inclined surface inclined at a predetermined angle in the circumferential direction. When the coil spring 4 is loosened, as shown in FIG. 7B, one of the overlapping parts 7 is located on the inclined surface side of the other overlapping part 8 closest to the armature suction surface 1a, and the armature is 5 and the sub-armature 5', and when tightening the coil spring 4, one overlapping part 7 is attracted to the armature attraction surface 1a as shown in FIG. 8B. This eliminates the gap _g1 and eliminates the step g between the armature 5 and the sub-armature 5' by being located on the inclined surface of the other overlapping portion 8 on the side farthest from the armature suction surface 1a. Note that 1e and 1e are magnetic flux blocking holes provided in the armature attraction surface 1a, and these magnetic flux blocking holes 1e and 1e direct the magnetic flux of the electromagnetic coil 6 toward the armature 5 and the sub armature 5'. ing.

Since the electromagnetic spring clutch of the embodiment has the above-described configuration, when voltage is applied to the electromagnetic coil 6 in order to transmit the rotational torque of the input rotor 1 to the output rotor 3, the armature 5 and sub-armature 5' move toward the armature suction surface 1a. At first, only the armature 5 is attracted to the armature suction surface 1a, and the gap _g1 becomes zero (in this state,
Since the coil spring 4 has not yet been tightened, a gap g exists between the armature 5 and the sub-armature 5', and the sub-armature 5' is not attracted to the armature suction surface 1a). Therefore, only the armature 5 is attached to the input rotor 1. It moves in the direction of rotation and tightens the coil spring 4.

Therefore, the armature 5 rotates relative to the sub-armature 5', and the overlapping part 7 provided on the armature 5 is located at the most armature suction surface 1a of the overlapping part 8 of the sub-armature 5'.
The sub-armature 5' gradually approaches the armature suction surface 1a side, and when the coil spring 4 is completely wound, the sub-armature 5' moves to the side of the inclined surface away from the armature as shown in FIG. 5' is also attracted to the armature attraction surface 1a, and the input rotor 1 and output rotor 3 begin to rotate at the same speed. At this time, the step g between the armature 5 and the sub-armature 5' becomes zero, and the sub-armature 5' is attracted to the armature suction surface 1a, which causes the sub-armature 5' to slide on the armature suction surface 1a. This prevents the sub-armature 5' from wearing out and causing abnormal noise.

As explained above, the present invention includes the input rotor 1,
Bearing 2 attached to input rotor 1
, an input rotor 1, an output rotor 3 rotatably attached to the compressor, and an output rotor 3.
and the input rotor 1, and the coil spring 4 contracts in diameter when a winding force is applied to integrally connect the output rotor 3 and the input rotor 1, and the coil spring 4 is fixed to one end of the coil spring 4. and a sub-armature 5' that is movably attached to the output rotor 3 in the axial direction and movable relative to the armature 5 in the circumferential direction.
and an electromagnetic spring clutch equipped with an electromagnetic coil 6 that attracts the sub-armature 5' and the armature 5 to the armature suction surface 1a and tightens the coil spring 4 by the armature 5.
are provided with overlapping parts 7 and 8 that overlap each other, and the joint surface 9 of these overlapping parts 7 and 8 is connected to the armature suction surface 1 when the coil spring 4 is loosened.
A step g is created between the surfaces of the armature 5 and the sub-armature 5' facing a, and the step g is formed on an inclined surface in the circumferential direction so as to eliminate the step g when the coil spring 4 is tightened. In order to transmit the rotational torque of the rotor 1 to the output rotor 3, when voltage is applied to the electromagnetic coil 6, the armature 5 is first attracted to the armature attraction surface 1a, and then rotates integrally with the input rotor 1, and the coil Since the sub-armature 5' is attracted to the armature suction surface 1a after the spring 4 is tightened, the sub-armature 5' does not slip on the armature suction surface 1a, thereby preventing wear of the sub-armature 5' and generation of abnormal noise. This has the effect of preventing damage and increasing the durability of the sub-armature 5'.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional electromagnetic spring clutch, Fig. 2 is a longitudinal sectional view of another conventional example, Fig. 3 is a longitudinal sectional view of the electromagnetic spring clutch of the present invention, and Fig. 4 is an enlarged view of the main parts. Figure 5 is a plan view of the armature, Figure 6 is a plan view of the sub-armature, and Figure 7 is a plan view of the armature.
Figure A is an enlarged cross-sectional view of the main part when the coil spring is loosened, Figure 7B is a cross-sectional view taken along line A-A in Figure 7A, and Figure 8A is an enlarged view of the main part when the coil spring is tightened. The sectional view, FIG. 8B, is a sectional view taken along the line B--B of FIG. 8A. 1... Input rotor, 1a... Armature suction surface, 2... Bearing, 3... Output rotor, 4...
...Coil spring, 5...Armature, 5'
...Sub armature, 6...Electromagnetic coil, 7,
8...Overlapping part, 9...Joining surface.

Claims (1)

[Scope of utility model registration request] An input rotor 1, a bearing 2 attached to the input rotor 1, and an output rotor 3 attached to the compressor so as to be rotatable with the input rotor 1.
, a coil spring 4 which is installed astride the output rotor 3 and the input rotor 1 and which contracts in diameter when a winding force is applied to integrally connect the output rotor 3 and the input rotor 1; and one end side of the coil spring 4. an armature 5 that is fixed to the output rotor 3; a sub-armature 5' that is movably attached to the output rotor 3 in the axial direction and that is movable relative to the armature 5 in the circumferential direction; is attracted to the armature suction surface 1a, and the coil spring 4 is attached by the armature 5.
In the electromagnetic spring clutch equipped with an electromagnetic coil 6 for tightening the armature 5 and the sub-armature 5', the armature 5 and the sub-armature 5' have overlapped parts 7,
At the same time, the joint surface 9 of these overlapping parts 7 and 8 is made to form a step g between the surfaces of the armature 5 and the sub-armature 5' facing the armature suction surface 1a when the coil spring 4 is loosened, and the coil An electromagnetic spring clutch characterized in that an inclined surface in the circumferential direction is formed so as to eliminate the step g when the spring 4 is tightened.