JP2002206566A - Driving force transmission controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress repetitive fluctuation of a driving force transmission characteristic caused by duty control of a current flowing to an electromagnetic coil in a driving force transmission controller controlling driving force by controlling duty of an electromagnet. SOLUTION: In this driving force transmission controller controlling the driving force by controlling the duty of the electromagnet, since the driving force τ3 is smoothed by composing the electromagnet by two coils 13a and 13b and respectively shifting phases of voltages applied to the two coils about 180 deg., the fluctuation of the driving force characteristic caused by duty control which has been a problem in prior art can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a driving force transmission control device.

[0002]

2. Description of the Related Art As one type of a driving force transmission control device, as disclosed in Japanese Utility Model Laid-Open No. 6-16731, a magnetic path forming member, a clutch located on one side of the magnetic path forming member, and a clutch are disclosed. And an electromagnetic clutch having an electromagnet located on the other side of the magnetic path forming member.

In this type of electromagnetic clutch, when an electric current is applied to the electromagnetic coil of the electromagnet, a magnetic force for attracting the armature is generated in the electromagnet, and the armature is attracted to the friction clutch and presses the clutch according to the magnetic force. Actuate to engage.

[0004]

By the way, in the electromagnetic clutch of this type, the current supplied to the electromagnetic coil of the electromagnet is controlled to a predetermined current value by duty control. In the duty control, a predetermined voltage is intermittently applied to the electromagnetic coil of the electromagnet.
By changing the F cycle (duty ratio),
Controls the current flow. For this reason, the current value supplied to the electromagnetic coil fluctuates repeatedly between ON and OFF of the applied voltage, and this current fluctuation causes repetitive fluctuation of the magnetic force. As a result, as shown in FIG. 4, the magnetic force generated by energizing the electromagnetic coil fluctuates, and the engaging force of the clutch is repeatedly fluctuated. In the clutch, abnormal noise is generated due to the repetitive fluctuation of the engaging force. There is a risk.

Further, in the electromagnetic clutch, the clutch characteristics are repeatedly changed, which affects the operation of devices using the electromagnetic clutch as an actuator. For example, in a driving force transmission control device using the clutch as a pilot clutch mechanism, the transmission torque of the main clutch repeatedly fluctuates via the cam mechanism as the conversion mechanism due to the repetitive fluctuation of the clutch characteristics of the electromagnetic clutch. In addition, abnormal noise may be generated in the main clutch due to the repetitive fluctuation of the transmission torque.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to suppress a repetitive variation of a driving force transmission characteristic caused by a duty control of a current supplied to an electromagnetic coil in a driving force transmission control device of this type.

[0007]

According to a first aspect of the present invention, there is provided a driving force transmission control device for controlling a driving force by duty-controlling an electromagnet, wherein the electromagnet comprises two or more n coils. A driving force transmission control device characterized in that the phases of voltages applied to the n coils are shifted.

According to a second aspect of the present invention, in the driving force transmission control device according to the first aspect, the phases of the voltages applied to the n coils are shifted by a natural number multiple of substantially 360 / n degrees. This is a driving force transmission control device.

According to a third aspect of the present invention, in the driving force transmission control device according to the first or second aspect, the coils are composed of two coils, and the phases of voltages applied to these coils are shifted by approximately 180 degrees. Is a driving force transmission control device.

According to a fourth aspect of the present invention, in the driving force transmission control device according to any one of the first to third aspects, a magnetic path forming member positioned between the electromagnet via a predetermined gap and the magnetic path forming member are sandwiched. A clutch and an armature located on the opposite side of the electromagnet, and configured by an electromagnetic clutch that attracts the armature to the electromagnet side by a magnetic force generated by energizing the electromagnet and engages the clutch to generate torque. A driving force transmission control device.

According to a fifth aspect of the present invention, in the driving force transmission control device according to any one of the first to fourth aspects, the main rotating member is disposed between the outer rotating member and the inner rotating member which are coaxially and relatively rotatable. A clutch, a pilot mechanism that generates torque by energizing the electromagnet, and a torque converter that is disposed between the main clutch and the pilot mechanism and that converts torque generated by the pilot mechanism into thrust force and transmits the thrust force to the main clutch. A driving force transmission control device including a conversion mechanism for operating the main clutch.

[0012]

According to the first aspect of the present invention, in the driving force transmission control device for controlling the driving force by controlling the duty of the electromagnet, the magnetic force generated by the electromagnet is smoothed. Vibration caused by the duty control can be reduced.

According to the second or third aspect of the invention, the fluctuation of the magnetic force generated by each coil is canceled out, so that the vibration is remarkably reduced. In the third aspect of the invention, the electromagnet is formed at a relatively low cost. be able to.

According to the fourth aspect of the present invention, since the repetitive fluctuation of the engaging force of the electromagnetic clutch is reduced, it is possible to reduce the generation of abnormal noise due to the repetitive fluctuation of the engaging force of the clutch.

According to the fifth aspect of the present invention, the fluctuation of the torque generated by the pilot mechanism can be reduced, so that the fluctuation of the torque generated by the pilot mechanism repeatedly changes the transmission torque of the main clutch via the conversion mechanism. And the noise generated by the main clutch due to the repetitive fluctuation of the transmission torque can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a driving force transmission device 10 employing an electromagnetic clutch as a pilot clutch mechanism. As shown in FIG. 2, the driving force transmission device 10 is mounted on a driving force transmission path to a rear wheel side of a four-wheel drive vehicle.
In addition, since the main part of the driving force transmission device 10 is substantially symmetrical with respect to the axis, FIG.
Are shown, and substantially the other half are omitted.

In the four-wheel drive vehicle, the transaxle 21 integrally includes a transmission, a transfer, and a front differential. The driving force of the engine 22 is transmitted through the front differential 23 of the transaxle 21 to both axle shafts 24.
a, 24a to drive the left and right front wheels 24b, 24b and to the first propeller shaft 25 side. The first propeller shaft 25 is connected to the driving force transmission device 1.
When the first propeller shaft 25 and the second propeller shaft 26 are connected so as to be able to transmit torque, the driving force is transmitted to the rear differential 27 and the rear differential 27 27 to both axle shafts 28a, 28a
To drive the left and right rear wheels 28b, 28b.

Each wheel is provided with rotation sensors 5 to 8, and wheel speed signals output from the rotation sensors 5 to 8 are data corresponding to or proportional to the rotation speed [rpm] of each drivable wheel. It is. The throttle valve opening sensor 2 outputs a value of the throttle valve opening m. The output data and the output from the drive mode switch 1 are transmitted to a control device (hereinafter referred to as an ECU).
18 is input. The driving force transmission control device 19 includes the driving force transmission device 10 and the ECU 18.

The driving force transmitting device 10 is disposed between the first propeller shaft 25 and the second propeller shaft 26. As shown in FIG. 1, the outer case 10a, the inner shaft 10b, the main clutch 10c, A pilot clutch mechanism 10d and a cam mechanism 10e are provided. The electromagnetic clutch according to one example of the present invention is employed as a pilot clutch mechanism 10d.

An outer case 10a constituting the driving force transmitting device 10 is formed by a bottomed cylindrical housing 11a and a rear cover 11b fitted and screwed into a rear end opening of the housing 11a to cover the opening. Have been.

The inner shaft 10b is connected to the rear cover 11
b is coaxially inserted into the outer case 10a through the central portion of the outer case 10 in a liquid-tight manner, and in a state where the axial direction is regulated,
It is rotatably supported by the housing 11a and the rear cover 11b. The tip of the second propeller shaft 26 is connected to the inner shaft 10b so as to be able to transmit torque.
The housing 11a that forms the outer case 10a
A first propeller shaft 25 is connected to a front end of the first propeller shaft 25 so as to be able to transmit torque.

The main clutch 10c is a wet-type multi-plate type friction clutch, and has a large number of clutch plates (an inner clutch plate 12a and an outer clutch plate 12b).
And is disposed in the housing 11a. Each inner clutch plate 1 constituting the main clutch 10c
The outer clutch plate 2b is spline-fitted to the outer periphery of the inner shaft 10b and axially movable, and each outer clutch plate 12b is spline-fitted to the inner periphery of the housing 11a and axially movable. It is attached.
The respective inner clutch plates 12a and the respective outer clutch plates 12b are alternately positioned, are in contact with each other and frictionally engage with each other, and are separated from each other to be in a free state.

The pilot clutch mechanism 10d is an electromagnetic clutch, and includes an electromagnet 13, a friction clutch 14, an armature 15, and a yoke 16. The electromagnet 13 has an annular shape, and is formed of two coils 13 a and 13 b wound around a rotation axis and arranged in the axial direction.
1b is fitted into the annular recess 11d via a predetermined gap. The yoke 16 is fixed to the vehicle body while being rotatably supported on the outer periphery of the rear end of the rear cover 11b.

The friction clutch 14 is a wet-type, multi-plate type friction clutch composed of a plurality of outer clutch plates 14a and inner clutch plates 14b. Each outer clutch plate 14a is spline-fitted to the inner periphery of the housing 11a, and The inner clutch plates 14b are mounted so as to be movable to a cam mechanism 10 to be described later.
e, is spline-fitted around the outer periphery of the first cam member 17a constituting the first cam member 17a so as to be movable in the axial direction.

The armature 15 has an annular shape, is spline-fitted to the inner periphery of the housing 11a, and is mounted so as to be movable in the axial direction.

The thus constructed pilot clutch mechanism 10
In d, the electromagnetic coils 13a, 13b of the electromagnet 13
When the power is supplied to the yoke 16 with the electromagnet 13 as a base point,
A loop-shaped circulating magnetic path through which a magnetic flux circulating through the rear cover 11b, the friction clutch 14 and the armature 15 passes is formed. The current supplied to the electromagnet 13 is controlled to a predetermined current value set by duty control in the ECU 18.

The power supply to the electromagnetic coil of the electromagnet 13 is turned on and off by a switching operation of the drive mode changeover switch 1, so that three drive modes described later can be selected. The switch is disposed near the driver's seat in the passenger compartment so that the driver can easily operate the switch.
If the driving force transmission control device 19 is configured to have only a second driving mode (AUTO mode) described later, the switch can be omitted.

The cam mechanism 10e, which is a conversion mechanism, includes a first cam member 17a, a second cam member 17b, and a cam follower 17c. First cam member 17a
Is rotatably fitted to the outer periphery of the inner shaft 10b and rotatably supported by the rear cover 11b, and the inner clutch plate 14b of the friction clutch 14 is spline-fitted to the outer periphery. Second cam member 1
7b is spline-fitted to the outer periphery of the inner shaft 10b and is assembled so as to be integrally rotatable, and is located opposite the rear side of the inner clutch plate 12a of the main clutch mechanism 10c. A ball-shaped cam follower 17c is interposed between the opposing cam grooves of the first cam member 17a and the second cam member 17b.

In the driving force transmission device 10 having such a configuration, the electromagnet 1 constituting the pilot clutch mechanism 10d is used.
When the third electromagnetic coils 13a and 13b are in the non-energized state, no magnetic path is formed, and the friction clutch 14 is in the non-engaged state. Therefore, the pilot clutch mechanism 10d is in a non-operating state, and the first cam member 17a constituting the cam mechanism 10e can rotate integrally with the second cam member 17b via the cam follower 17c.
c is in an inactive state. For this reason, the vehicle constitutes a first drive mode (2WD mode) of two-wheel drive.

On the other hand, the electromagnetic coils 13a, 1
3b, the pilot clutch mechanism 1
At 0d, a loop-shaped circulating magnetic path starting from the electromagnet 13 is formed to generate a magnetic force.
5 is aspirated. For this reason, the armature 15 presses the friction clutch 14 to frictionally engage and generate a torque, and connects the first cam member 17a of the cam mechanism 10e to the outer case 10a side, so that the armature 15 is in contact with the second cam member 17b. Cause relative rotation. As a result, in the cam mechanism 10e, a thrust force is generated in a direction in which the cam follower 17c separates the two cam members 17a and 17b from each other.

For this reason, the second cam member 17b is pushed toward the main clutch 10c, and presses the main clutch 10c against the inner wall of the housing 11a. Combine. As a result, torque is transmitted between the outer case 10a and the inner shaft 10b, and the vehicle is driven by the first propeller shaft 25.
And the second propeller shaft 26 constitutes a second drive mode (AUTO mode) of four-wheel drive between the non-directly connected state and the directly connected state. In this drive mode, the driving force distribution ratio between the front and rear wheels can be controlled in a range from 100: 0 (two-wheel drive state) to the directly connected state according to the running state of the vehicle.

In the second drive mode, the electromagnetic coils 13a and 13b are driven in accordance with the running state of the vehicle and the road surface on the basis of signals from various sensors such as the wheel speed sensors 5 to 8 and the throttle valve opening sensor 2. The duty control of the current supplied to the friction clutch 14 controls the frictional engagement force of the friction clutch 14, that is, the torque transmitted to the rear wheels.

The electromagnetic coils 13a, 1 of the electromagnet 13
3b, the attraction force of the electromagnet 13 on the armature 15 increases, and the armature 15
Is strongly sucked, the frictional engagement force of the friction clutch 14 is increased, and the relative rotation between the two cam members 17a, 17b is increased. As a result, the cam follower 17c increases the pressing force on the second cam member 17b, and
0c is set to the coupled state. For this reason, the vehicle constitutes a third drive mode (LOCK mode) in which the first propeller shaft 25 and the second propeller shaft 26 are four-wheel drive in a directly connected state.

Here, the configuration of the ECU 18 and the processing executed by the ECU 18 in the driving force transmission control device 19 according to the present invention will be described based on the block diagram of FIG. 6 and the flowchart of FIG.

As shown in FIG. 6, the ECU 18 calculates the transmission torque command value T from the input from the drive mode changeover switch 1, the throttle valve opening m, and the wheel speeds N1 to N4.
3; a duty ratio calculating means 18b for calculating a duty ratio according to the transmission torque command value T3; and applying a voltage to the two coils 13a and 13b of the electromagnet 13 based on the duty ratio. (Hereinafter referred to as F)
Drive circuit 18 for driving 18e, 18f
c, 18d.

Next, the processing executed by the ECU 18 will be described with reference to FIG.

First, in step S1, it is determined whether or not the vehicle is in a first drive mode (2WD mode). If the drive mode is the first drive mode, the vehicle is driven by two wheels (step S11). If it is not the first drive mode, the process proceeds to step S2, and it is determined whether it is the third drive mode (LOCK mode). If the driving mode is the third driving mode, the vehicle enters the third driving mode in which the first propeller shaft 25 and the second propeller shaft 26 are directly connected to each other (step S1).
2).

If it is not the third drive mode, that is, if it is the second drive mode (AUTO mode), the throttle valve opening m and the wheel speeds N1 to N4 are input in step S3, and the process proceeds to step S4. The process proceeds to calculate the vehicle speed. The vehicle speed is an average value of the wheel speeds of the rear wheels 28b, 28b (N3 + N4) / 2
Is used.

Then, the flow shifts to step S5, where a transmission torque T1 corresponding to the throttle valve opening m and a gain G corresponding to the vehicle speed are obtained from a map stored in a ROM (not shown).
1 is determined. The transmission torque T1 is set to increase as the throttle valve opening m increases, and the gain G1 decreases as the vehicle speed increases.

Next, at step S6, the differential rotational speed ΔN = (N1 + N2-N3-N4) / 2 between the front and rear wheels is calculated. Then, the process proceeds to step S7 to determine a transmission torque T2 corresponding to the differential rotation speed ΔN and a gain G2 corresponding to the vehicle speed from a map stored in a ROM (not shown). The transmission torque T2 is set to increase as the differential rotation speed ΔN increases, and the gain G2 decreases as the vehicle speed increases.

Subsequently, the process proceeds to step S8, where a transmission torque command value T3 is determined from the transmission torques T1 and T2 and the gains G1 and G2 determined in steps S5 and S7 (T3 = G1.T1 + G2.T2).

Then, a duty ratio corresponding to the transmission torque command value T3 is calculated (step S9), and based on this duty ratio, the drive circuits 18c and 18d control the FET 18 so as to apply a voltage to the coils 13a and 13b of the electromagnet 13.
e and 18f are driven (step S10).

Thus, in the driving force transmitting device 10, the coils constituting the electromagnet 13 are the coils 13a, 1a.
3b, and when the current supplied to the electromagnetic coil of the electromagnet 13 is controlled by duty control, the phases of the duty-controlled voltages of the two coils 13a and 13b are shifted from each other by approximately 180 degrees. ing. As a result, the phases of the conduction currents become approximately 18
Because of the 0 degree shift, the magnetic force generated in proportion to the energizing current is smoothed as a whole, and the repetitive fluctuation of the torque generated by the clutch engaged by the magnetic force is reduced.

The graph of FIG. 3 shows the time-dependent changes in the voltage, current and magnetic force in the duty control.
The current is controlled to a predetermined value by changing the N-OFF cycle (duty ratio). In the graph,
A wide pulse V1 indicated by a solid line and a narrow pulse V1 'indicated by a dashed line indicate a voltage. The width of each pulse V1 and V1' is ON (t1, t1 '), and the interval width is OFF. Time (t2, t2 '). The duty ratio in the duty control is t1 / (t1 + t2), t1 '
/ (T1 '+ t2').

In the duty control, the applied voltage is controlled ON / OFF as indicated by a pulse V1 to control, for example, the current value of the energized current as indicated by a curve I1 (solid line), and the magnetic force (attraction force of the armature) is set as follows. Formula ~
Therefore, the magnetic force can be similarly controlled as shown by a curve H1 (solid line). Further, by controlling the applied voltage to be ON-OFF like the pulse V1 ', for example, the current value of the energizing current is changed to a curve I1' (dashed line).
, And the magnetic force (attraction force of the armature) can be similarly controlled as shown by a curve H1 ′.

B = μH H = kIl where Φ: magnetic flux, B: magnetic flux density, S: area through which magnetic flux passes, μ: magnetic permeability, H: magnetic field strength, k: constant (1 / (2
π)), I: current, l: number of turns of the coil.

The graph of FIG. 4 shows the change over time of the friction torque in the pilot clutch mechanism by the duty control according to the prior art. Since the pilot clutch mechanism is constituted by an electromagnetic clutch, the response is high and the applied voltage is high. Is turned on and off like a pulse V2, a pilot torque such as a curve τ2 proportional to the magnetic force H2 (attraction force of the armature) is generated when the clutch is engaged. Since this pilot torque amplifies the transmission torque of the main clutch several times to ten and several times by the cam mechanism,
The amplified torque is repeatedly changed while the applied voltage is ON-OFF controlled, so that the driving force transmission characteristic is repeatedly changed.

However, in the driving force transmission control device 19 according to the present embodiment, the coils constituting the electromagnet 13 are the same as the conventional coils, the number of turns is halved, and the directions of the magnetic forces are the same. (For example, the direction of the winding and the direction of the current are respectively matched). When the current supplied to the electromagnetic coil of the electromagnet 13 is controlled by duty control, the voltages applied to the two coils 13a and 13b are shifted by approximately 180 degrees at the same duty ratio as in the related art as shown in FIG. , The phases of the currents are shifted by approximately 180 degrees.

When the voltages V3a and V3b are applied to the two coils 13a and 13b at the same duty ratio, the values of the currents I3a and I3b are the same as in the conventional case, but the number of turns of each coil is half that in the conventional case. The current values I3a, I3
The values H3a and H3b of the magnetic force generated in proportion to b are half those of the related art. The total magnetic force H3 is equal to the conventional one because the respective magnetic forces generated in the two coils 13a and 13b are combined (H3 = H3a + H3b). Moreover, the voltage V applied to the two coils 13a and 13b
Since the phases of 3a and V3b are each shifted by approximately 180 degrees, the phases of the magnetic forces H3a and H3b are each shifted by approximately 180 degrees, and the magnetic force H3 as a whole is smoothed. Accordingly, since the magnetic force H3 is smoothed, the magnetic force H3 is reduced.
The variation of the pilot torque τ3 generated by the friction clutch 14 engaged by the third clutch 3 is reduced, and the repeated variation of the driving force transmission characteristic transmitted by the main clutch 10c is reduced.

Thus, the pilot clutch mechanism 10
The frictional engagement force of d is maintained in a stable state with a small fluctuation range, and the generation of abnormal noise from the friction clutch 14 due to the repeated variation of the frictional engagement force is reduced. Accordingly, in the driving force transmission device 10, the acting force transmitted to the main clutch 10c via the cam mechanism 10e is stable with little fluctuation, and the fluctuation of the transmission torque in the main clutch 10c is reduced. At the same time, occurrence of abnormal noise in the main clutch 10c is reduced.

In this embodiment, since the electromagnet 13 can be formed at a relatively low cost, two coils 13a and 13b are used. However, three or more coils may be used.

For example, when three coils are used, the phases of the voltages applied to the respective coils are shifted by approximately 120 degrees. When four coils are used, the phases of the voltages applied to the coils are shifted by approximately 90 degrees.
Alternatively, when there are four coils, the same phase voltage may be applied to two coils, and the phases may be shifted by 180 degrees.

In short, when the electromagnet is composed of two or more n coils, the same operation and effect as in the present embodiment can be obtained by shifting the phases of the voltages for duty control by a natural number of approximately 360 / n degrees. can get.

If the phases of the voltages applied to the n coils are shifted little by little, the magnetic force is smoothed as compared with the conventional one, and the torque fluctuation can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a driving force transmission device according to an example of the present invention.

FIG. 2 is a schematic configuration diagram of a four-wheel drive vehicle equipped with the driving force transmission device.

FIG. 3 is a graph showing temporal changes in voltage, current, and magnetic force in duty control.

FIG. 4 is a graph showing time-dependent changes in voltage, current, magnetic force, and torque in duty control in the related art.

FIG. 5 is a graph showing temporal changes in voltage, current, magnetic force, and torque in duty control according to the present invention.

FIG. 6 is a configuration diagram of an ECU in the driving force transmission device according to the present invention.

FIG. 7 is a flowchart of a process executed by an ECU in the driving force transmission device according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 drive mode changeover switch 2 throttle valve opening sensor 5 wheel speed sensor 6 wheel speed sensor 7 wheel speed sensor 8 wheel speed sensor 10 driving force transmission device 10a outer case 10b inner shaft 10c main clutch 10d pilot clutch mechanism 10e cam mechanism 11a housing 11b Rear cover 11c Cylindrical body 11d Recess 12a Inner clutch plate 12b Outer clutch plate 13 Electromagnet 14 Friction clutch 14a Outer clutch plate 14b Inner clutch plate 15 Armature 16 Yoke 17a First cam member 17b Second cam member 17c Cam follower 18 Control device ( ECU) 18a Command value determination means 18b Duty ratio calculation means 18c Drive circuit 18d Drive circuit 18e Transistor (FET) 1 f transistor (FET) 21 transaxle 22 Engine 23 Front differential 24a axle shaft 24b front wheel 25 propeller shaft 26 propeller shaft 27 rear wheel rear differential 28a axle shaft 28b

Claims (5)

[Claims] 1. A driving force transmission control device for controlling a driving force by duty-controlling an electromagnet, wherein said electromagnet includes two or more n coils and a phase of a voltage applied to said n coils. Driving force transmission control device, characterized in that: 2. The driving force transmission control device according to claim 1, wherein the phases of the voltages applied to the n coils are shifted by a natural number multiple of approximately 360 / n degrees. Control device. 3. The driving force transmission control device according to claim 1, wherein said coil is composed of two coils, and the phases of voltages applied to these coils are shifted by approximately 180 degrees, respectively. Power transmission control device. 4. The driving force transmission control device according to claim 1, wherein the electromagnet includes a magnetic path forming member positioned at a predetermined distance from the electromagnet, and the electromagnet sandwiching the magnetic path forming member. A clutch and an armature located on the opposite side of the electromagnetic clutch, and an electromagnetic clutch that attracts the armature to the electromagnet side by a magnetic force generated by energizing the electromagnet and engages the clutch to generate torque. A driving force transmission control device. 5. The driving force transmission control device according to claim 1, wherein a main clutch disposed between an outer rotating member and an inner rotating member that are coaxially and relatively rotatable with each other; A pilot mechanism that generates torque by energizing the electromagnet; and a torque converter, which is disposed between the main clutch and the pilot mechanism, converts torque generated by the pilot mechanism into a thrust force, and transmits the thrust force to the main clutch to transmit the main clutch. A driving force transmission control device comprising a conversion mechanism for operating the driving force.