JPS6182023A - Electromagnetic clutch of electromagnetic type booster - Google Patents

Abstract

PURPOSE:To reduce noise and permit the smooth transmission of a necessary torque by applying a mechanical multiple-disc clutch onto the electromagnetic clutch of an electromagnetic type booster and reducing the connection noise on clutch connection. CONSTITUTION:When an electromagnetic coil 44 is in excitation state, magnetic fluxes are formed around the vacant space which an elliptical hole 43 forms. Attraction forces act between clutches 37-40 and an annular body 36b, which are joined integrally. Since the clutches 37-40 and the annular body 36b are arranged through a very small gap, a connection noise is hardly generated in attraction operation. Further, in connection state, a wide frictional surface for frictional contact can be provided, and the torque transmission capacity can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electromagnetic clutch with an electromagnetic booster 'Ic,i used in an electric power steering device.

(Prior art) An electric M-type booster used in electric power steering equipment is equipped with an electric motor inside, and when torque is applied to the input shaft, it detects the torque difference between the input shaft and the output shaft. The electric motor is operated based on this torque information, and the output shaft is assisted by the rotational torque.

By the way, MlvJ41! When transmitting rotational torque to the output shaft, torque transmission is generally made possible by operating an electromagnetic crack. 'The electromagnetic clutch allows auxiliary torque to be applied to the output shaft at the appropriate timing and when needed.

(Problems to be Solved by the Present Invention) 1! of the electromagnetic booster as described above! For magnetic clutches, tl
When the tm clutch 7 is operated, the driving clutch plate supported by a spring member and the driven clutch plate are bonded and integrated, which is undesirable because a collision noise is generated.

Also, the torque transmission capacity is high, [Supply for one operation 71! It is desirable that the current is small and that the characteristics of the supplied current and clutch transmission force are approximately proportional.

Thus, the present invention has characteristics such as low clutch operation noise, high torque transmission capacity, low current consumption, and increased clutch transmission force proportional to the supplied current. The purpose of the present invention is to provide an electromagnetic clutch for a compact and lightweight electromagnetic booster.

(Means for solving the problem) □ □ The present invention provides a WJ4 motor consisting of a built-in electric motor.
! ! A Jl clutch plate that rotates integrally with the J part side and is movable in the axial direction, and a second clutch plate that rotates integrally with the driven part side such as the output shaft and is movable in the axial direction. , arranged so as to be superimposed on each other, and an electromagnetic coil arranged near each of the clutch plates, so that when the electromagnetic coil is excited, the clutch plates are coupled and integrated into a connected state. This is what I did.

(Embodiment) A preferred embodiment of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal cross-sectional view of an electromagnetic booster according to the present invention, and the cross section is formed by bending the cut surface at 90 degrees at the center. FIG. 2 is a sectional view taken along line A--A in FIG. 1.

(1) is a human-powered shaft that is rotatably supported by bearings (2) and (3) and has a steering wheel (not shown) at the outer end; , (7) is an output shaft rotatably supported. The human power shaft (1) and the output shaft (4) are arranged coaxially, and each inner end is connected to the zero human power shaft (8) by a torsion bar (8) located at the center shaft.
1) and the output shaft (4), each opposing inner end is connected to the human power shaft (1).
The inner end of the output shaft (4) is fitted into the enlarged diameter opening end of the output shaft (4) via the bearing (3).

In the above torsion bar (8), the input shaft (1) is connected to the output shaft (
4) such that it is at a predetermined intermediate angle with respect to: Ag! and fixed to the input shaft (1) with the screw (8).

In the above, external rotational torque applied to the input shaft (1) is transmitted to the output shaft (0) while being twisted by the torsion bar (8).

Note that (10) is a steering column that accommodates and surrounds the input shaft (1) and forms a part of the case of the electromagnetic booster.

Around the part where the opposite ends of the human power shaft (1) and the output shaft (0) fit together, there is a torque detection part (11 ).The torque detection unit (11) is provided with a steering column (1
0), and a cylindrical movable part (13) disposed around the part in the mating position and movable in the axial direction. Ru. The output terminal of the differential transformer (12) is connected to an electric circuit that electrically detects torque, and this electric circuit determines the amount and direction of armature current according to the magnitude of torque and its direction of action. Has a control function.

The movable part (13) has a pin (+) as shown in FIG.
4) and (+4) engage the input shaft (1), and the pins (+5) and (+5) engage the output shaft (4). Pin (+4), (14) and pin (+5),
The mounting position (15) is provided with a phase difference of 90°. In this case, the long hole (13a) that engages with the pin (eye) (14) is formed parallel to the axis of the torsion bar (8), and the long hole (13a) that engages with the pin (ls) (15) is formed parallel to the axis of the torsion bar (8). +3b) is formed at a twisted position at a predetermined angle with the axis. Further, the movable part (13) is biased toward the left in the drawing 1tS1 by a coil spring (16).

In the above configuration, a gap (!l) is created between the pin (15) and the elongated hole (13b). This amount of offset is eliminated by the coil spring (1B), and the pin (15) is in contact with the surface (13b-1), while one surface (13b-2) is idle.

According to the above configuration, rotational torque is transmitted to the output shaft (0) via the torsion bar (8) on which the input shaft (1) rotates, but at this time, the rotational torque is transmitted between the input shaft (1) and the output shaft (4). A relative angular difference occurs between the movable parts (13
) moves in the left-right direction in FIG. The amount of movement of the movable vJ part (13) is proportional to the torque difference generated between the input shaft (1) and the output shaft (0), and the amount of movement is proportional to the torque difference generated between the input shaft (1) and the output shaft (0).
The above torque can be detected by electrically detecting it in step 2).

A structure of an electric motor (18) housed in a cylindrical case (17) is arranged around the output shaft (4). Case(
For example, a pair of magnets (17) forming magnetic poles are mounted on the inner peripheral surface of the
9) is fixed. Further, around the output shaft (4), a cylindrical shaft (21) rotatably provided with bearings (6), (7), and (20) is equipped with an iron core (22) and a winding (23). A rotor (24) is provided. The -8 wire (23) above is connected to the magnet (
+9) and (+9) rotate at right angles.

Also, (25) is a commutator, and the commutator (25) has a winding (2
The terminal (23a) of 3) is in the desired direction 'i!' with respect to the a line (23). The wires are connected so that the machine electronic current flows. Commutator (
A brush (27) urged by a coil spring (28) is pressed into contact with the brush (25).
) supplies armature current from the power supply.

Torque is applied to the input shaft (1) from the outside, and the torque detection section (1) is applied between the human power shaft (1) and the output shaft (4).
When torque is detected in step 1), armature current is supplied to the winding (23) based on the action of the control circuit. Then, the electric motor (+8) operates, and the rotor (20) is connected to the input shaft (1).
) rotates in the same direction as the direction of rotation.

The bearing (20) that rotatably supports the left side of the sleeve (21) of the rotor (20) in the figure is a two-stage planetary gear mechanism (28A3, (28B)) that constitutes the reduction gear t (28).
is fixed to the right end opening (29a) of the cylindrical internal gear (29). There you are again.

Next, the speed reduction device (2nd) consists of the two-stage planetary gear mechanism (28A) and (28B) as described above. The front planetary gear mechanism (28A) includes a large FMiM wheel (3G) formed at the left end of the cylindrical shaft (21'), the internal gear (29), and, for example, three planets meshed between them. Gear (31)・
It consists of... Also, the planetary gear mechanism (28
B) shows the sun gear (33) and the internal gear (29) formed around the cylindrical shaft (32a) of the carrier member (32) to which the Okuki planetary pulley (3[)... It is composed of a planetary gear (31') meshed between the two.

Even more! The i-star gears (31') are pivotally connected to a second carrier member (35) rotatably provided around the output shaft (4) with a bearing (34). This carrier member [35
) has three projecting pieces (
35a)... is formed.

On the other hand, the output shaft (4) is formed with an annular part (38a) having a constant width that faces the protruding piece (35a) of the carrier member (35) on the inside, and is substantially connected to the case (38a). 17
) has a U-shaped cross section and extends in the radial direction so as to touch the inner surface of the ring body (3
8b) is fixedly installed. Cylindrical body (3B
) and the output shaft (0) are connected by a C-fixed spline fitting in the circumferential direction of the output shaft.

Also the above El! Three protrusions (38a-1) are formed at regular intervals on the outer peripheral surface of g (38a).

This ring portion (Ha) and the protruding piece (
35a) =-+7) IIJI has four clutch plates (37) and (38).

(39) and (40) are provided. The four clutch plates are stacked and arranged in layers. Two of these clutches (37) and (39) are engaged with the carrier member (35).

Clutch plate (38), (4G) is the cylindrical body (36)]0
0 part 38a).

The shapes of the clutch plates (37), (38), and (39) are shown in Figure 3.The clutch plates (3?) and (38) have three notches (41) on the outer periphery. This notch (4
1)... engages with the protruding piece (35a)... Also, the clutch plate (38) has three notches (42) on the inner periphery.
..., and this notch (42) ... is the ring part (38a
) is engaged with the protrusion (38a-1).

The inner periphery of the clutch plate (40) is also similar to the clutch plate (38). In this way, clutch plates (37), (3B)
, (39).

(40) is restricted in movement in the circumferential direction by the respective engaging portions. However, it is movable in the axial direction.

Furthermore, arc-shaped elongated holes (43) are formed in the clutch and chi plates (37), (38), and (39). Such a long hole (43) is also formed in the ring body (38b).

The above clutch plates (37), (38), (39),
(4G) and the ring body (38b) are formed of magnetic material.

An electromagnetic coil (44) is placed in the space (Sl) formed by the ring body (3flb). This electromagnetic coil (44) is
The ring body (45) is fixed to the inner peripheral surface of the case (17) and is made of a magnetic material and has a U-shaped cross section. This ittm coil (40) has a torque detection unit (
(2) The excitation Fi1 current is supplied at an appropriate timing based on the action of the control circuit.

In the above, when torque is applied from the outside to the input shaft (1), the torque detection section (11) detects the force between the human power shaft (1) and the output shaft (4).
) is detected. Signal processing is performed based on the upper direction detected by the torque detection unit (11), and the first rotor (2
An armature current is supplied to 4), the first motor (18) is operated, and an excitation current is supplied to the '+'lt magnetic coil (44), thereby bringing the electromagnetic clutch (46) into a connected state. Then, the rotational torque of the rotor (24) becomes the first
, second planetary gear mechanism (28A), (28B), carrier member (35), clutch plate (37), (3B)
, (38).

(40), and is transmitted to the output shaft (4) in this order.

Clutch plates (37), (38) of electromagnetic clutch (46)
.

(39) and (40) are alternately arranged with clutch plates (3?) and (39) that engage on the motor side and clutch plates (H) and (40) that engage on the output shaft side. . When the electromagnetic coil (44) is in a de-energized state, the clutch plate (37)
.

(38), (39), (4G) and ring (3[1b)
The opposing end faces are in sliding contact with a slight gap between them. On the other hand, when the electromagnetic coil (44) is in an excited state, around the void formed by the elongated hole (43)...
Annular clutch plates (37), (38), (39), (4
A magnetic flux is formed through each clutch plate (37),
An attractive force acts between (38), (39), (40) and the ring body (38b), so that they are combined and integrated. This brings the electromagnetic clutch (46) into the connected state.

Facing each clutch plate (37), (3B), (39),
(40), the ring body (38b) is disposed with a very small gap, so when it is sucked, it hardly occurs before connection, and in the connected state, each clutch plate,
In order to bring the end faces of the ring into contact with each other using electromagnetic attractive force, ff
One surface can be made wider and the torque transmission capacity can be increased.

Also, the ring body (38b) and clutch plates (37), (38)
, (313).

In the detached state of (40), since a spring or the like is not used to make the detached state, the relationship between the excitation current of the electromagnetic coil and (44) and the torque transmitted by the electromagnetic clutch is ff1
As shown in Figure 4, there is a proportional relationship. Therefore, there is a proportional relationship applied to the input shaft. Therefore, the connecting operation of the electromagnetic clutch (4B) can be controlled with a current proportional to the torque applied to the input shaft. Therefore, a small amount of current is not consumed, and problems such as heat generation of the electromagnetic coil (44), reduction in suction force due to heat generation, and burnout are solved.

Furthermore, according to the above configuration, the electromagnetic clutch can be made smaller. That is, even if the radial dimension of the clutch plates etc. is reduced, the torque transmission capacity can be increased by increasing the number of clutch plates, so that the electromagnetic clutch can be made smaller as a whole.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, a so-called mechanical multi-plate clutch is applied to the electromagnetic clutch of the electric Fii type booster, so that the time before the clutch is connected is reduced. In addition, since no spring material is used to support the clutch plate, torque transmission acid can be generated in proportion to the excitation current of the electromagnetic coil. For this reason, if applied to an electromagnetic booster, it is possible to reduce noise and smoothly transmit the necessary torque according to the load with a minimum amount of current.

i again! Since the contact area of the clutch plate in the magnetic clutch can be increased, 1! Even if the excitation current of the magnetic coil is small, a large torque can be transmitted.

In addition, by increasing the number of clutch plates, the radial dimension of the clutch plates can be reduced without changing the transmission capacity, and thereby the electromagnetic clutch can be made smaller.

[Brief explanation of drawings]

Figure 1 shows an electromagnetic booster according to the present invention, with a center line of 90
° Longitudinal cross-sectional view of the cut surface formed by bending, Figure 2 is the 1st
A diagram showing a cross section along line A-A in the figure and a side view of the movable part, 3rd
The figure is a perspective view showing the shape of the clutch plate, and FIG. 4 is a diagram showing the operating characteristics of the electromagnetic clutch. In the drawing, (1) is the input shaft, (4) is the output shaft, (11)
is the torque detection unit, (18) is the electric motor, (2aj is the deceleration? e position, (28^), (28B) are the planetary gear mechanism, (
35) are carrier members, ('37), (38), (38
), (40) is the clutch plate, (40 is the electromagnetic coil, (40) is the clutch plate, (40 is the electromagnetic coil,
B) is an electromagnetic clutch.

Claims (1)

[Claims] A first clutch plate that rotates integrally with the driving part and is movable in the axial direction, and a second clutch plate that rotates integrally with the driven part and is movable in the axial direction are mutually connected. An electromagnetic type double, characterized in that an electromagnetic coil is disposed close to each of the clutch plates, and when the electromagnetic coil is excited, the clutch plates are coupled and integrated. Electromagnetic clutch of power device.