JPH02180318A - Centrifugal type friction engagement clutch at vehicle starter - Google Patents

Abstract

PURPOSE:To increase a torque capacity without increasing the weight of a weight, by arranging a constituting in which centrifugal force acting on the weight is increased by a lever ratio and acts on a friction shoe. CONSTITUTION:A weight assembly 6 is equipped with a predetermined lengthed arm 6b having a weight 6a at the tip portion, and supports its base end portion X swingably by means of a clutch disk 2, and in addition, presses pushingly and connects to a friction shoe 5 a base end portion vicinity Y on the weight 6a side of the arm 6b. When centrifugal force F acts on the weight 6a in an outer diameter direction as the disk 2 rotates, the arm 6b swings in the outer diameter direction with the base end portion X as a center, and is magnified by a lever ratio b/a between a distance (a) which is from the base end portion X to an acting on point Y, and a distance (b) which is to a force point (a weight gravity center point) F, and acts on the friction shoe 5. As a result, the friction shoe 5 comes into contact with a drum 3 with a large pushing pressure, and has a large torque capacity since at the time of a low speed rotation.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a centrifugal lock-up clutch used with a vehicle starting device, particularly a fluid starting device such as a fluid coupling or a fluid torque converter. This invention relates to the structure of a centrifugal friction engagement clutch that sometimes has a large torque capacity.

(b) Conventional technology - In vehicles such as automobiles, torque from an engine is transmitted to an automatic transmission etc. via a fluid starting device, but a centrifugal lock-up clutch is installed in the fluid starting device. It is also known that it has a lot of meaning.

Conventionally, a centrifugal friction clutch used in the centrifugal lock-up clutch has friction shoes and weights provided at equal intervals on the outer periphery of a clutch disc, as shown in, for example, Japanese Patent Laid-Open No. 60-69332. , the friction shoe is provided with locking portions at both ends, and these locking portions are positioned in a predetermined relationship in the circumferential direction to protrusions provided on the disk, and also lock in a predetermined relationship to the weight, and the weight is further held in a predetermined relationship over the circumferential protrusion. A load spring is provided between the friction shoe and the weight and biased in the inner radial direction by a tractor spring.

As a result, in the low speed range, the friction shoe is separated from the drum together with the weight by the retractor spring, and the clutch is in the released state, and in the medium and low speed range, the centrifugal force acting on the weight is transferred to the load spring. acts on the friction shoe through the drum, presses the friction shoe against the drum, and engages the clutch with a predetermined torque capacity, which torque capacity increases in response to an increase in rotational speed. When a predetermined high-speed state is reached, the weight comes into contact with the protrusion of the clutch disc, and the centrifugal force caused by the weight does not act on the friction shoe. From then on, the clutch is engaged by the centrifugal force acting on the friction shoe. .

The centrifugal lock-up clutch prevents the torque capacity from becoming excessive due to an increase in rotational speed, absorbs the effects of drive vibration caused by knocking, etc., and has the effect of reducing FA dynamics and noise in the vehicle, but in the near future When the slip clutch proposed by the applicant is applied to a lock-up clutch (Japanese Patent Application No. 70158/1983; unpublished) that combines a centrifugal friction engagement clutch, the torque capacity, especially at low speeds, is insufficient. .

In other words, the lock-up clutch proposed by the present applicant absorbs drive vibration etc. by combining a slip clutch, especially a slip clutch with a torque capacity corresponding to the load torque, so the centrifugal friction engagement clutch has a low It is desirable to have something that does not slip as much as possible from the rotation range to the high rotation range.

(c) Problem to be solved by the invention In conventional centrifugal friction engagement clutches, the torque capacity is determined by the outward centrifugal force in the radial direction, which is determined by the weight of weights and friction shoes, etc., and the rotational speed of the clutch drum. .

Therefore, even if the structure is such that the centrifugal force of the weight acts on the friction shoe even in the high speed range, if you try to secure a high torque capacity from the low rotation range, the structure of the conventional centrifugal friction engagement clutch cannot It is also necessary to increase the amount of the friction shoes, which increases the inertia of the starting device itself when the vehicle starts, resulting in a configuration that is disadvantageous in terms of acceleration performance, fuel efficiency, etc. of the vehicle.

Therefore, the present invention provides a centrifugal friction clutch in a starting device which aims to increase the torque capacity without increasing the weight ffl by increasing the centrifugal force acting on the weight by lever ratio and acting on the friction shoe. The purpose is to provide the following.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, referring to FIG. 1, the clutch disc (2) which is an output member and the input member A centrifugal friction engagement clutch (1) for a vehicle starting device, comprising a drum (3), a friction shoe (5) and a weight assembly (6) attached to the clutch disc. , the weight assembly (6) includes an arm (6b) of a predetermined length having a weight (6a) at the tip thereof,
And the base end (X) of the arm is connected to the clutch disc (
2), the arm is swingably supported, and the arm near the base end (Y) on the weight side is pressed and connected to the friction shoe (5).

Further, the weight assembly (6) is pressed and connected to the friction shoe (5) near the tip (z) of the weight assembly (6) while being swung by a predetermined amount due to centrifugal force.

Specifically, the friction shoe (5) has a contact portion (7) in the center that can come into contact with the drum (3), and U-shaped bent portions (5b) and (5c) at both ends. and left and right protrusions (9a) provided on the clutch disc (2).
, (9b) holds a retainer spring (10), and the outer diameter surface of the retainer spring (10) is brought into contact with the back surface of the friction shoe contact portion, and at least one end (10a) of the spring is folded into the friction shoe. Curved section (5b)
two protrusions (10b) and (10C) are formed at a predetermined distance apart on the inner diameter surface of the retainer spring (10), and the protrusions are A retractor spring (11) having four engaging portions (11a) and (llb) is brought into contact with the inner diameter surface of the retainer spring, and both side portions (11d) and (11e) are connected to the friction shoe bent portions (5b) and (11). 5c) abuts against the tip and urges the shoe in the inner radial direction, and supports the weight assembly (6) on the clutch drum (2) via the strut member (12), and the weight near the strut member The assembly (6) is pressed and connected to the friction shoe (5) via one recess (lla) of the retractor spring (11) and one protrusion (10b) of the retainer spring (10), and the weight Near the tip of the assembly (6) is inserted through the other recess (llb) of the retractor spring and the other protrusion (10c) of the retainer spring.
) so that it can be pressed and connected.

(e) Effect Based on the above configuration, when centrifugal force (F) is applied in the outer radial direction to the way (6a) of the weight assembly (6) as the clutch disc (2) rotates, the arm (6b)
swings in the outer radial direction around the fulcrum (X), and the distance ffi (a) from the fulcrum (X) to the point of action (Y) and the distance (b) from the point of force (center of gravity of the weight) (F) are lever ratio (b/
The force is increased in a) and acts on the friction shoe (5). This causes the friction shoe (5) to apply a large pressing force to the drum (
3) and has a large torque capacity even at low speed rotation.

Further, when the clutch disc (2) reaches a predetermined rotational speed and the weight assembly (6) further swings in the outer radial direction, the tip of the weight (6a) comes into contact with the point of action (Z), and from then on, as described above, The boosting force due to the lever ratio is stopped, and the centrifugal force acting on the weight assembly is reduced to two points (Y) and (
2) acts on the friction shoe (5).

Note that the symbols inside the cuff are used to refer to the drawings, but do not limit equivalent configurations, and even if the symbols are the same, they are described based on the scope of the claims, so they are described below. The name may be different from the name of the example shown.

(f) Example Embodiments of the present invention will be described below along with the drawings.

As shown in FIG. 7, the vehicle fluid starting device 30 is suitable for application to an automatic continuously variable transmission incorporating a belt-type continuously variable transmission (for example, Japanese Patent Application No. 70158/1983; It consists of a fluid coupling 31 and a lockup device 32. The fluid coupling 31 has a coupling case 33 connected to the engine crankshaft, and a pump impeller 35 constituting the input side is provided in the case 33, and a rotor of a hydraulic pump is attached to the hub portion 35a of the coupling case 33. are connected. Further, a turbine runner 36 that constitutes the output side is arranged opposite to the pump impeller 35, and the runner 36 is provided with thrust bearings 37 and 37 in the case 33.
The hub portion 36b is connected via a pressure regulating cam 40 to the hub portion 36b, which is positioned and supported via the hub portion 36b, and the hub portion 36b is connected to the hub portion 36c, which is connected to the input shaft (not shown) of the continuously variable transmission. have. The pressure regulating cam mechanism 40 consists of two end cams, a driving side cam part 40a and a driven side cam part 40b, and the end faces of both these cam parts have a recessed part, and a roller is interposed between them. Further, a boss portion 36a is connected to the turbine runner 36, and a bearing 41 is connected between the boss portion 36a and the hub portion 36b.
The driving side cam portion 40a is engaged with the turbine runner 36 so as to be movable only in the axial direction, and the spline formed on the hub portion 36b The driven side cam portion 40b is engaged.Furthermore, a slip clutch 42 is disposed to sandwich the pressure regulating cam mechanism 40.

The slip clutch 42 engages with a clutch hub 43 which is connected to a centrifugal frictional engagement device to be described later and becomes an input side, two clutch plates 45 connected to the hub, and a spline of the hub portion 36b. A clutch disc 46 is attached to the plate 45 and the disc 46 with a snap ring, and a disc spring 49 is provided to apply a predetermined load to the plate 45 and the disc 46 via a spacer 47. The cam mechanism 40 is interposed between the two regulated clutch plates 45,45.

Further, a disk 2 extending in the radial direction is fixed to the clutch hub 47, and the base end portion 2c of the disk extending in the inner radial direction is connected to the stepped portion 33b of the front case 33a constituting the coupling case 33. The centrifugal friction engagement clutch according to the present invention is supported in the radial direction via the bush 44a and in the thrust direction via the bush 44b, and furthermore, the distal end portion extending in the outer radial direction is connected via the damper spring 49. It is connected to 1.

As shown in FIGS. 1 and 2, the centrifugal friction engagement clutch 1 is interposed between the drum 3 made up of the front coupling case 33a and the clutch disc 2, and the disc It has a plurality of friction shoes 5 and weights 6 attached to notches 2a formed at equal intervals on the outer periphery of 2. The friction shoe 5 has a circular arc portion 5a in the center.
It has bent parts 5b and 5c formed in a U-shape at both ends thereof, and a friction material 7 constituting a contact part with the drum 3 is attached to the outer peripheral surface of the arc part 5a. has been done. Furthermore, protrusions 9a and 9b made of pins are fixed to both ends in the circumferential direction of the notch 2a of the clutch disc 2, and a retainer spring 10 made of a plate spring material is held across both protrusions 9a. There is. The outer peripheral surface of the retainer spring 10 is in contact with the inner peripheral surface of the circular arc portion of the friction shoe 5, and two protrusions 10b and 10c are formed on the inner peripheral surface of the retainer spring 10 at a predetermined distance apart in the circumferential direction. Furthermore, the upstream end 10a in the rotational direction R abuts against the bent portion 5b of the friction shoe, and rotates integrally in the circumferential direction. Furthermore, as shown in detail in FIG. 3, both ends of the retainer spring 10 are cut off at their image sides to form a rising part 10e and a receiving part 10f, and the rising part 10e or the projection 9b ( 9a), the retainer spring 10 and the friction shoe 5 are attached to the disk 2.
The receiver is held against the portion 10f or the protrusion 9b (9a
) and bears the reaction force in the direction of the outer diameter. Further, a retractor spring 11 is disposed on the inner peripheral side of the retainer spring 10, and the retractor spring 11 is connected to the protrusions 10b, 10 of the retainer spring.
It has recesses 11a and 11b that engage with the friction shoes 5, and both ends lid and lie of the friction shoes 5 have bent portions 5b and 5.
c, and together with the retainer spring 10 urges the friction shoe 5 in the inner radial direction.

A recess 2b is formed in the rotational direction downstream of the notch 2a of the clutch disc 2, and a strut member 12 is swingably supported in the recess at a predetermined rising angle. As shown in FIG. 5, the strut member 12 is made of a polygonal block, and has an engagement groove 12a with the four parts 2b formed at its base end, and a shoulder for supporting the weight assembly at its distal end. Parts 12b, 12b
and a protrusion 12c for abutting the retractor spring. Then, the protrusion 12c of the strut member 12
is the rotational downstream concave portion 11 of the retractor spring 11
The protrusion 11 of the retainer spring abuts against the downstream side surface of a.
The friction shoe 5 is supported via a. Therefore, based on the slight decrease in the rising angle θ of the strut member 12, the friction shoe 5 generates a large pressing force in the outer diameter direction in the pattern and presses against the tram 3. On the other hand, the weight assembly 6, as shown in detail in FIG.
The base end 6c is bifurcated and bent, and is supported by the shoulders 12b, 12b of the strut member 12 so as to be able to swing freely in the approximate radial direction and to be prevented from coming off. The disc 2 is guided so as to sandwich the disc 2 between the notches 6d. The weight assembly 6 has an arm 6a in the vicinity of its base end Y.
is in contact with the concave portion 11a of the retractor spring, and therefore, the centrifugal force F acting on the weight 6a is caused by the lever action between the point of action Y, which is the contact point, and the point of force F, which is the center of gravity of the weight, from the fulcrum X by the strut member 12. Ratio (b/a
) and acts on the friction shoe 5 via the retractor spring 11 and retainer spring 10. Further, when the weight assembly 6 swings a predetermined amount and its tip comes into contact with the other four parts 11b, the above-mentioned boosting force is stopped and the centrifugal force is applied to the two points of action Y.

2 acts on the friction shoe 5.

Next, the operation of this embodiment will be explained.

The rotation of the engine crankshaft is transmitted to the coupling case 33 in the starting device 30, further transmitted from the pump impeller 35 of the fluid coupling 31 to the turbine runner 36 via an oil flow, and then to the pressure regulating cam mechanism 40. The signal is transmitted to the knob portion 36b and then to the input shaft of the continuously variable transmission.

At this time, at the start of running, the rotational speed of the turbine runner 36 is low, and therefore acts on the weight assembly 6 and shoe 5 of the centrifugal friction engagement clutch 1 connected to the turbine launch via the slip clutch 42. The centrifugal force is small, the clutch 1 is in a disengaged state, and is transmitted exclusively through the fluid coupling 31, so that the vehicle starts moving smoothly.

That is, as shown in FIG. 2, a centrifugal friction engagement clutch 1
is in a clutch released state in which the friction shoe 5 is biased in the inner radial direction by the retractor spring 11, and the friction material 7 and the inner circumferential surface of the drum 3 are separated. From this state, when the rotation of the clutch disc 2 connected to the output side of the fluid coupling 31 increases, the weight assembly 6 moves in the outer radial direction due to centrifugal force.

At this time, as shown in FIG.
The centrifugal force F acting on the center of gravity of the weight 6a is
The lever ratio (b
/a), the force is greatly increased and the retractor spring 11
It acts on one recess 11a of the retainer spring 10, and acts on the friction shoe 5 via the protrusion 10b of the retainer spring 10.

Then, the friction material 7 attached to the friction shoe 5 comes into contact with the inner peripheral surface of the drum 3, and the rotation R of the drum 3, that is, the coupling case 33, is transmitted to the friction shoe L-5, and the shoe 5 Move in the swing rotation direction R. Then, one protrusion 10b of the retainer spring 10 and one recess 1 of the retractor spring 11 move together with the friction shoe 5.
The distal end O of the strut member 12 is moved in the same direction via 1a, and the strut member 12 swings about the base end B in a direction in which the rising angle θ decreases. As a result, the strut member 12 moves the friction shoe 5 in the outer radial direction via the spring 10.11, and presses the friction shoe 5 by the self-biasing action of the pattern.

The circumferential force transmitted from the drum 3 to the R1 friction shoe 5 is transmitted to the rear end bent portion 5b as shown by the arrow in FIG.
The force is transmitted from the spring 10 to the end 10a of the retainer spring 10, and further from the protrusion 10a of the spring 10 to the strut member 1 via the recess 11b of the tractor spring 11.
2, and is transmitted from the strut member 12 to the clutch disc 2 via the groove 2b.

Furthermore, when the rotation of the clutch disc 2 increases and the weight assembly 6 swings in the outer radial direction, and its tip comes into contact with the recess 11b which is the other point of action 2, the centrifugal force acting on the weight assembly 6 is , two points of action Y, Z
acts on the friction shoe 5 at the above-mentioned lever ratio (b/a
) will be stopped.

Therefore, as shown in FIG. 8, this centrifugal friction engagement clutch 1 has a specific axial The torque capacity increases rapidly due to the characteristic P that rises at a steep angle from a low rotation speed, and when the boosting by the lever ratio described above is stopped at a predetermined rotation speed, the slope becomes relatively gentle from the characteristic P2. The torque capacity is as follows. This makes it possible to cover the best fuel consumption characteristics and maximum power characteristics, and the centrifugal friction engagement clutch 1 can transmit power without slipping in all operating conditions except at the beginning of startup.

The torque transmitted via the centrifugal friction engagement clutch 1 is transmitted from the disk 2 via the damper spring 49 to the clutch hub 43, and further via the slip clutch 42 to the hub portion 36b. and,
Even if the centrifugal friction engagement clutch 1 is in the connected state, a large load is applied to the output side 36b due to kickdown, sudden braking, upshifting, etc., or vibration is generated on the input side due to engine knocking, etc. Due to the occurrence of
When a sudden load change occurs, the slip clutch 42 slips, and the load or vibration described above is smoothly absorbed.

Immediately thereafter, the pressure regulating cam mechanism 40 generates an axial force corresponding to the load torque, and this axial force acts on the slip clutch 40, so that the slip clutch increases its torque capacity in response to the increase in the load torque. Therefore, for example, during kickdown, the load torque once becomes zero and then rises rapidly, but at this rise, the slip clutch 40 slips and the power is first transmitted via the fluid coupling 31, and as a result, the load torque increases. The torque capacity of spring clutch 40 is correspondingly increased to transmit power with reduced or no slip clutch slippage. In other words, when a slip occurs, it automatically responds,
- After absorbing sudden load fluctuations by the fluid coupling 31,
The torque capacity of the slip clutch 40 is increased to transmit rotation from the direct connection path to the automatic transmission body via the centrifugal lockup device 32.

The base end 2c of the clutch disc 2 is supported in the radial direction by the step 33b of the cup link case 33 via a bushing 44a, and also in the thrust direction by the bushing 44a.
Therefore, when the centrifugal friction engagement clutch 1 is released, that is, when the disk 2 and the case 33 rotate relative to each other, no large force is applied to the bushes 44a and 44b, and the centrifugal When the friction engagement clutch 1 is engaged and a large radial force is applied, the case 33 and the disk 2 rotate together, and thrust rotation does not occur in the bushes 44a, 44b.

Note that in the above embodiment, the centrifugal friction engagement clutch 1 is incorporated into the fluid starting device 30 consisting of the fluid coupling 31.
The invention is not limited to this, but it may be incorporated into a fluid starting device consisting of a fluid torque converter, and is suitable for use in an automatic transmission incorporating a belt type continuously variable transmission, but is not limited to this. Of course, the present invention may also be applied to the stepped automatic transmission.

Furthermore, although the above-mentioned device is referred to as a starting device, as explained above, it is not a device that functions only when starting, but functions throughout the entire running of the vehicle. Since it is easy to understand, the name is retained and does not limit equivalent rights.

(G) As described in detail, according to the present invention, the centrifugal force acting on the weight assembly (6) is multiplied by the lever ratio (b/a) and is applied to the friction shoe (5). , without increasing the weight of the weight assembly (6), friction shoe (5), etc., it is possible to secure a high torque capacity from a relatively low rotation speed, thereby improving the acceleration performance and fuel efficiency of the wheel. Something will happen.

Furthermore, when the weight assembly (6) is oscillated by a predetermined amount and stopped using the lever ratio described above, it is possible to rapidly increase the torque capacity at low rotation speeds, but when the rotation speed exceeds the predetermined rotation speed, the torque capacity can be rapidly increased. In this case, it is possible to increase the torque capacity by setting a relatively gentle angle, which may cause excessive centrifugal force to act on the drum (3), damaging the drum (3) or damaging the coupling case (33). It is possible to increase the strength of such members and prevent them from increasing in weight.

Furthermore, the friction shoe (5) and the spring spring (10)
When the weight assembly (6) is held by the retractor splinter (11), and the weight assembly (6) is supported by the strut member (12), it is necessary to fix each component member to each other by welding or the like. This eliminates problems related to adhesion such as heat effects caused by welding, cracking and coming off, and improves reliability, as well as ease of assembly and maintenance.

Furthermore, when this centrifugal friction engagement clutch (1) is applied to a lockup device (32) combined with a slip clutch (42), the centrifugal friction engagement clutch (1) is fully engaged at a relatively low rotation speed. Although it is possible to improve fuel efficiency, etc., the slip clutch (42) absorbs vibrations on the input side due to sudden load fluctuations due to kick town, etc. and knocking, etc., and achieves smooth power transmission. Can be done.

Furthermore, when an axial force is applied to the slip clutch (42) by the cam mechanism (40), the torque capacity of the slip clutch (42) increases in response to the load torque, so that it can automatically respond to any driving situation. Therefore, it is possible to improve not only fuel efficiency but also drivability.

In addition, the clutch disc (2) is connected to the fluid starting device (30).
When the disk (2a) is supported in the radial direction by the stepped portion (33b) of the case (33), a large radial force acts on the disk (2a) in the inner radial direction as the centrifugal friction clutch (1) engages. In the case of clutch engagement, since the case (33) and the disk (2) that make up the drum (3) are rotating, a large load is generated on the rotating support members such as the bush (44a). Moreover, the large radial force caused by the centrifugal friction clutch (1) is absorbed within the case (33a) and does not act on other members.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a centrifugal friction engagement clutch according to the present invention in an engaged state, and FIG. 2 is a front view showing its disengaged state. FIG. 3 is a perspective view showing the end portion of the
FIG. 4 is a perspective view showing the weight assembly, and FIG. 5 is a perspective view showing the strut member. Moreover, FIG. 6 is a diagram showing the force transmission path of the present centrifugal friction engagement clutch. Furthermore, FIG. 7 is a diagram showing a vehicle starting device according to the present invention, and FIG. 8 is a diagram showing the best fuel consumption characteristics and maximum power characteristics in a continuously variable transmission, and the torque capacity characteristics of a centrifugal friction engagement clutch. It is a diagram.

Claims (1)

[Claims] 1. Centrifugal friction in a vehicle starting device comprising a clutch disc as an output member, a drum as an input member, and a friction shoe and weight assembly attached to the clutch disc. An engagement clutch, wherein the weight assembly includes an arm of a predetermined length having a weight at a distal end, and a proximal end of the arm is swingably supported on the clutch disc,
A centrifugal friction engagement clutch for a vehicle starting device, further comprising: a portion of the arm near the base end on the weight side pressed against and connected to the friction shoe. 2. Centrifugal friction in the vehicle starting device according to claim 1, wherein the weight assembly is pressed and connected to the friction shoe near the tip of the weight assembly while being oscillated by a predetermined amount due to centrifugal force. Engagement clutch. 3. The friction shoe has a contact portion in the center that can come into contact with the drum and has U-shaped bent portions at both ends, and retainer springs are held on left and right protrusions provided on the clutch disc. , and the outer diameter surface of the retainer spring is in contact with the back surface of the friction shoe contact portion, and at least one end of the spring is in contact with the friction shoe bent portion to connect the retainer spring so as to be able to transmit force in the circumferential direction; Two protrusions are formed at a predetermined distance apart on the inner diameter surface of the spring, and a retractor spring having a recess that engages with the protrusions is brought into contact with the inner diameter surface of the retainer spring, and both sides of the retractor spring are bent into the friction shoes. The weight assembly is supported by the clutch drum via the strut member, and the weight assembly near the strut member is pushed into the retractor spring's one recess and The retainer spring is pressed and connected to the friction shoe through one protrusion, and the vicinity of the tip of the weight assembly is pressed against the friction shoe through the other recess of the retractor spring and the other protrusion of the retainer spring. - The centrifugal friction engagement clutch in the vehicle starting device according to claim 2, which is configured to be able to connect. 4. The vehicle starting device includes a fluid starting device such as a fluid coupling or a fluid torque converter, and a slip clutch is interposed between the hub portion connected to the turbine runner of the fluid starting device and the clutch disc. The centrifugal friction engagement clutch in a vehicle starting device according to claim 1, comprising: 5. A cam mechanism that generates an axial force corresponding to the load torque is installed in the torque transmission path from the turbine runner to the hub portion, and the axial force from the cam mechanism acts on the slip clutch. A centrifugal friction engagement clutch in the vehicle starting device described above. 6. The vehicle starting device includes a fluid starting device such as a fluid coupling or a fluid torque converter, and a case of the fluid starting device constitutes the drum and a stepped portion that supports the clutch disc in the radial direction. The centrifugal friction engagement clutch in a vehicle starting device according to claim 1, comprising: