JPS61102326A - Vehicle power transmission device - Google Patents

Abstract

PURPOSE:To eliminate nonconformities in the tight corner braking phenomenon of a part-time four wheel drive vehicle and troublesome manipulation of the latter, by providing a hydraulic control circuit including a hydraulic pressure control means between the discharge port and suction port of a hydraulic port. CONSTITUTION:A four wheel drive coupling device 13 is composed of a vane pump 20 and a hydraulic control circuit 21, and a rotor 20a and a cam ring 20b are integrally rotated through the intermediary of oil under the static pressure of the oil when the discharge port of the pump 20 is blocked. Further, oil passages 26, 27 are communicated with a discharge oil passage 41 through two changeover check valves 31, 32 serving as changeover means, and a relief valve 33 serving as an oil control means is disposed in the discharge oil passage 41. In this device 13 the discharge pressure is controlled to be prevented from exceeding a predetermined value by means of a relief valve 33 and therefore, changeover between the four wheel drive and the two wheel drive is automatically made, and the four wheel drive condition having a drive force in accordance with the differential speed between the front and rear wheels may be obtained.

Description

[Detailed Description of the Invention] [Industrial Field of Application] [Prior Art] In a four-wheel drive vehicle in which the front and rear wheels are driven at the same speed, the effective radius of the front and rear tires is slightly different. If there is a difference in the speed of the vehicle, or in the case of cornering, the tires may slip due to the difference in the rolling path of the tires, and unreasonable force is applied to the drive system, so it is necessary to provide a means to prevent this.

For this reason, conventional full-time four-wheel drive vehicles have a first rotating shaft that transmits driving force to the front wheels and a second rotating shaft that transmits driving force to the rear wheels.
A third differential device called a cenotatef is used to transmit driving force even if there is a difference in rotational speed between the rotating shaft and the rotating shaft.Part-time 4-wheel drive @' It is disadvantageous compared to tc and because differential rotation is possible, it may not be possible to achieve 4-wheel drive when 4-wheel drive is required, and it requires a differential gear mechanism, etc., making the device even more complicated. I will invite you.

In addition, without providing a centatef, the drive connection part was
Japanese Patent No. 20521 proposes a method of absorbing the difference in rotational speed between the front and rear wheels by intervening a wet multi-disc clutch and sliding the flange during cornering, but the transmission torque There was a risk of burnout due to capacitance and slippage.

On the other hand, many Heart Time 4-wheel drive vehicles do not have center/vertical controls installed, so if there is a problem with the 4-wheel drive, such as a tight corner braking phenomenon that occurs when turning, it is possible to It is instructed to use wheel drive, which has the disadvantage that driving operations are complicated.

It is an object of the present invention to eliminate the drawbacks of conventional vehicles in which the front wheels and rear wheels are driven by the same engine, and to provide a compact and lightweight power transmission device for a vehicle.

[Means for solving problems]

The configuration of the present invention that achieves this object includes a first rotating shaft that transmits driving force to the front wheels and a first rotating shaft that transmits driving force to the rear wheels.
The second rotating shaft is connected via a hydraulic pump that is driven by the rotational speed difference between the first rotating shaft and the second rotating shaft and discharges an amount of oil according to the rotational speed difference. The suction port and the discharge port are switched depending on the relative rotation direction of the first rotating shaft and the second rotating shaft, and a hydraulic control means is provided between the oil passage between the discharge port and the suction port of the hydraulic port. It is characterized by being equipped with a hydraulic control circuit.

〔Example〕

Hereinafter, the content of the present invention will be specifically explained based on an example in which the present invention is applied to a four-wheel drive vehicle. .

In the first embodiment shown in FIGS. 1 to 3, a transmission 2 is connected to an engine 1 placed horizontally as shown in FIG. Driving force is taken out from gear 4 and sent to gear 6 at both ends via idle gear 5.
．． The driving force is transmitted to an intermediate transmission shaft 8 having a gear 7, and the driving force is transmitted from one gear 7 of this intermediate transmission shaft 8 to a differential device 10 for the front wheels 9 to drive the front wheels 9, while the driving force is transmitted to the front wheels 9. The generated driving force is directly transmitted to the first rotating shaft 11 via the gear 12, and then to the second rotating shaft 14 via the four-wheel drive drive coupling device 13.

The rear wheel 16 is connected to the rear wheel 16 via a gear mechanism 15 that changes the rotation direction.
The driving force is transmitted to the differential gear 17 for driving the rear wheels 16.

The second four-wheel drive drive coupling device 13 includes a vane pump 20, which is a hydraulic pump, as shown in FIG.
The rotor 20a of the vane pump 2o is connected to the first rotating shaft 11 through which the driving force to the front wheels 9 is directly transmitted, and the cam ring 20b is connected to the rear wheels 16. The second one that transmits the driving force
It is connected to the rotating shaft 14. The hydraulic pump 20 discharges an amount of oil proportional to its rotation speed, and there is relative rotation between the cam ring 20a and the cam ring 20b, that is, the first rotating shaft 11 and the second rotating shaft 14. When a relative rotation occurs between the vane pump 20 and the vane pump 20, it functions as a hydraulic pump and generates hydraulic pressure. The static pressure causes the rotor 20a and the cam ring 20b to rotate together like a rigid body.

For this reason, two pump chambers are formed at diagonal positions in the cam ring 20b, and four suction and discharge ports 22, 23, 24 and 25 are formed at almost diagonal positions, and the suction and discharge ports 22 at diagonal positions each have the same function.
．． 24 and suction/discharge ports 23 and 25 are respectively connected to the cam ring 2.
The first oil passage 26 and the second oil passage 27 communicate with each other via a mechanism that allows oil to flow to the stationary side even in the rotating state of 0b.

Further, an oil reservoir 30 is communicated between the first oil passage 26 and the second oil passage 27 via check valves 28 and 29, respectively.
Both oil passages 26 and 27 are connected to each other through two opposing switching check valves 31 and 32 that allow only flow from the oil reservoir 30 and only allow outflow between the first oil passage 26 and the second oil passage 27. , 27 are communicated with the discharge oil passage 41, and these two switching check valves 31 and 32 form a switching means, and the discharge oil passage 41
An IJ-F valve 5, which is a hydraulic control means, is disposed at the IJ-F valve 5. The relief valve 56 has an oil reservoir 30 and two check valves 28 .
A communication passage 5 is provided at the other end of the spring 34, and a spring 54 connects the IJ IJ
- A piston 36 is provided to control the opening pressure of the valve 33, and a control oil pressure controlled by duty acts on the other end of the piston 36. Then, a constant pressure oil pressure supplied through an orifice 57 is controlled by a solenoid valve 58 for duty control, and this solenoid valve 38 is electrically connected to a computer 39.

The engine rotation speed, the rotation speed of the first rotation shaft 110, and the rotation speed of the second rotation shaft 14 are input into the computer.

The hydraulic pressure acting on the other end of the piston 56 is controlled based on the throttle opening, brake operation detection switch, and steering angle detection signal. In addition, for the constant pressure oil pressure supplied through the orifice 37, if the transmission 2 is an automatic transmission, it is sufficient to use its control oil pressure.1If the transmission is a manual type, an oil pump may be installed, or The oil pressure can be secured using the oil pressure of the power steering, the oil pressure for the brake booster, the oil pressure obtained from the discharge port side of the vane pump 20, or the like. By using such a hydraulic control circuit 21, the discharge pressure is always maintained at IJ regardless of the relative rotational direction between the rotor 20a and the cam ring 20b.
Acts on the valve body of the IJ-F valve 35.

The driving state according to the number of four-wheel drive drive connections [values] such that the oil reservoir 30 communicates with the suction port is first set when the opening pressure of the relief valve 33 is kept constant only by the setting force of the spring 54. I will explain.

In a normal straight-ahead state, the effective radius of the tires of the front wheels 9 and the rear wheels 16 is the same, and the slip rotational speed of the tires is not small. During this time, there is no difference in rotational speed between the two. Therefore, the vane pump 20 does not generate hydraulic pressure (and the driving force is not transmitted to the rear wheels 16, resulting in two-wheel drive by the front wheels 9 only).

However, even when driving straight, the front wheels 9 usually slip within about 1 coefficient, even if there is no large slip like when accelerating.
The rotational speed difference caused by this is the difference between the first rotating shaft 11 and the second rotating shaft 1.
4, the engine knob 20 functions to generate oil pressure corresponding to this rotational speed difference, and the
The and cam ring 20b rotate together, and a driving force corresponding to the oil pressure and the pressure receiving area of the heel is transmitted to the rear wheels 16, resulting in a four-wheel drive state. The flow of oil in the hepump 20 in this case is as shown in FIG. 6 (al).
The oil pump 20a rotates relatively, and the suction/discharge port 23.25 becomes a suction port, and oil is sucked in from the oil reservoir 30 via the check valve 29.

The suction and discharge ports 22 and 24 serve as discharge ports and the check valve 28
．． At the same time as the switching check valve 32 is closed, the oil is guided to the relief valve 33 via the switching check valve 31. In FIG. 1, the solid line arrows indicate the flow of discharge oil, and the broken line arrows indicate the flow of suction oil.

Next, if the rotational speed of the front wheels 9 becomes very large compared to the rotational speed of the rear wheels 16 (1), for example, if the rear wheels tend to lock up when driving on a snowy road, when accelerating suddenly, or when braking,
The difference in rotational speed between the first rotating shaft 11 and the second rotating shaft 14 of the four-wheel drive drive coupling device 13 becomes very large, and oil flows in the vane pump 20 as shown in FIG. 3 (al). However, when a predetermined value is exceeded, the relief valve opens against the suffling 54 and the discharge pressure is controlled to be almost constant, and a constant driving force corresponding to the constant discharge pressure is applied to the rear wheels 16. The transmission is now in four-wheel drive mode.

As a result, the rotational speed of the front wheels 9 decreases and the rear wheels 16
The rotational speed of the front wheels increases, reducing the rotational speed difference (same function as a non-slip differential), thereby avoiding the situation where the drive torque to the rear wheels 16 is increased and the vehicle becomes unable to drive when the front wheels 9 slip. If this is possible and the rear wheels 16 are a little locked up, the brake torque of the front wheels 9 is increased to prevent the rear wheels 16 from flopping.

On the other hand, if the rotational speed of the front wheels 9 (・(2), the rear wheels 160 rotational speed becomes very large, 1. For example, if the front wheels 9 are slightly locked in the brake state, the first rotation of the four-wheel drive drive coupling device 13 A very large rotational speed difference occurs between the shaft 11 and the second rotating shaft 14 in the opposite direction to that described above, and in the vane pump 20, oil flows as shown in FIG. 6(b), and the suction and discharge ports 22゜24 becomes the oil suction port, and oil is sucked in from the oil reservoir 50 via the check valve 28. On the other hand, the suction/discharge port 23.25 becomes the discharge port and passes through the second oil passage 27 to check valve 29.Switching check valve 31 When the switch is closed, a large hydraulic pressure is introduced from the switching check valve 32 to the relief valve 53, and this hydraulic pressure is also kept constant by the IJ-F valve 33, and a constant driving force is transmitted to the rear wheels 16, and the four wheels are It becomes a driving state.

As a result, the brake torque to the rear wheels 16 is increased to prevent the front wheels 9 from locking.

In addition, during normal cornering, the rotational speed of the front wheels 9 is slightly higher than the rotational speed of the rear wheels 16, so that a brake torque acts on the front wheels 9 and a driving torque acts on the rear wheels 16.
Turning is performed in wheel drive mode.

In this way, by controlling the discharge pressure in the four-wheel drive drive coupling device 1 by the relief valve 53 so that it does not exceed a certain value, the conventional...-Tomeimu four-wheel drive vehicle requires a four-wheel drive state. In some cases, the driver's operation is now automatically switched between 4-wheel drive and 2-wheel drive, and 4-wheel drive is automatically switched between 4-wheel drive and 2-wheel drive.
Wheel drive condition is obtained. In addition, it is possible to make the center differential, which is always installed in full-time four-wheel drive vehicles, smaller and smaller, as well as to reduce weight and cost.

Next, when adjusting the opening pressure of the relief valve 33 by duty-controlling the hydraulic pressure acting on the lower end side of the piston 36, the discharge pressure of the vane pump 20 can be adjusted and controlled, and the driving force to the rear wheel 16 is adjusted. can be adjusted.

Therefore, the higher the load on the engine '1 becomes, the more the throttle opening signal is used to detect this and control the vane pump 20 to increase the discharge pressure.
The amount of driving force transmitted to the vehicle can be increased to allow the vehicle to travel.

Furthermore, the front wheels 9 and rear wheels 16 are prevented from locking by controlling the discharge pressure of the vane pump 20 to be increased when the operation state of the foot brake is detected by a brake operation detection switch and becomes QN. By shortening the braking distance, you can achieve stable braking conditions.

Furthermore, the steering angle is detected and the discharge pressure is controlled to be lower as the steering angle becomes larger.

This makes it possible to avoid tight corner braking and make smooth turns.

Further, the discharge pressure of the vane pump 20 can be adjusted and controlled according to the engine rotational speed and vehicle speed using each detection signal inputted to the computer to maintain a stable running condition.

Next, regarding a second embodiment in which the hydraulic control circuit 21 is different,
This will be explained based on FIG.

In the four-wheel drive drive coupling device 15 of the present embodiment, the configuration of the hydraulic pump 20 is +=- as described above, and between the first oil passage 26 and the second oil passage 27 of the hydraulic control circuit 21. Two cut-off check valves 31 and 52 (Fig. 3-(a)
In place of (see (b)), a C7-type switching valve 40 is provided.The oil passages at both ends of this switching valve 400 are connected to the first oil passage 26 or the second oil passage 27, respectively. It communicates with the oil filter O through the check valves 28 and 29, while the discharge oil passage 4 is connected to the intermediate part which is switched by the spool.
In addition, a hydraulic control valve 42 is provided in place of the relief valve 33, and a discharge oil passage 41 communicates between lands of a spool 42a provided with two runts, and a pressure regulating oil passage. The 4th filter is connected to the oil sump 0, and the spool 42a
The biasing force of the spring 42b acts on the left end of the valve, and the hydraulic pressure controlled by the duty of the orifice 37 and the solenoid valve 38 acts thereon. Therefore, the pressure regulating oil is adjusted to the pressure regulating oil path 4 due to the balance of the oil pressure in the discharge oil passage 41 due to the area difference between the two lands of the spool 42a with respect to the oil pressure controlled by the spring 42b and duty.
5 and returned to the suction side.

According to such a hydraulic control circuit 21, the first rotating shaft 110
When the rotational speed is relatively high, the pointer 20a is in the third position.
If it rotates clockwise as explained in Figure (a), the first oil passage 26 becomes the discharge side.

The second oil passage 27 is on the suction side. As a result, in the hydraulic control circuit 21 of FIG.
communicates with the discharge oil passage 41, the discharge oil is guided to the hydraulic control valve 42, and the pressure-regulated oil is sent to the suction side via the check valve 29 and circulated.

Further, when the rotational speed of the second rotating shaft 140 is relatively high, the cam ring 20b rotates clockwise as explained in FIG. 3 (bl), and the second oil passage 27 becomes the discharge side. 21\1 oil passage 26 is on the suction side.

As a result, in the hydraulic control circuit shown in Fig. 4,
Since the discharge pressure acts on the right end face of 0, the spool switches to the left end, the second oil passage 27 communicates with the discharge oil passage 41, the discharge oil is guided to the hydraulic control valve 42, and the pressure regulating oil is transferred to the check valve. 28 to the suction side for circulation.

In this way, even if the relative rotational direction between the first rotating shaft 11 and the second rotating shaft 14 deviates by degrees Celsius, the discharge pressure is always maintained at the discharge oil passage 41.
The discharge pressure of the hydraulic pump 20 can be controlled by adjusting the control pressure applied to the spool 42a by the duty control solenoid valve 5B, as described above.
It should be possible to obtain a driving state that corresponds to the 7-turn state.

Next, a fifth embodiment in which the hydraulic control circuit 21 is different will be described based on FIG. 5.

In this embodiment, a spool valve 45 controlled by ON-OFF of a solenoid valve 44 is used in place of the switching valve 40 described in the second embodiment, and between each land of a spool 45a having three lands. 1st oil passage 26.
The second oil passage 27 communicates with the check valve 28.
．． It communicates with the oil reservoir 30 and the pressure regulating oil passage 43 of the oil pressure control valve 42 via 29 . Further, a discharge oil passage 41 that is opened and closed by an intermediate land communicates with a hydraulic side diameter 1 valve 42 . For this spool valve 45.

A spring 45b is interposed on the left end side, while a solenoid valve 44 that is 0N-OFF controlled is provided on the upstream side of the orifice 46 on the right end side, and a computer 39 is connected to the solenoid valve 44. .

In such a hydraulic control circuit 21, when the relative rotational speed of the first rotating shaft 11 is high, if the rotor 20a rotates clockwise, the first The oil passage 26 is on the discharge side, and the second oil passage 27 is on the suction side.

At this time, the first rotating shaft 11 is input to the computer 39.
The rotational direction (relative rotational direction) of the hydraulic nozzle 200 is determined from the rotational speed of the second rotating shaft 14, and the solenoid valve 44 is turned ON to open the upstream side of the orifice 46, and the stool 45a is connected to the spring 45b and the second rotating shaft 14. 1 oil road 26
The first oil passage 26 and the discharge oil passage 41 are communicated with each other by setting the spool 45a at the right end position by the urging force due to the area difference between the lands of the oil discharged from the spool 45a. The oil in this discharge oil passage 41 is circulated in the same manner as in the case of FIG.

Further, in the case of FIG. 3(b) where the relative rotational speed of the second rotating shaft 14 becomes high and the cam ring 20b rotates clockwise, the second oil passage 27 becomes the discharge side.

The first oil passage 26 is on the suction side. In this case as well, an OFF signal is sent from the computer 9 to the solenoid valve 44, and hydraulic pressure acts on the right end surface of the spool 45a, and a spring is generated by the biasing force due to the area difference between the lands of the oil discharged from the second oil passage 27. 45b, the spool 45a is switched to the left end position, and the second oil passage 27 and the discharge oil passage 41 are communicated with each other. The oil led to this discharge oil passage 41 is circulated in the same manner as in the case of FIG. 4.

By using the spool valve 45 whose switching is controlled by the slide/id valve 44 in this manner, it is possible to always switch between the suction port and the discharge port regardless of the relative rotational direction of the hydraulic pump 20, and the spool valve can be operated reliably.

Next: A fourth embodiment in which the hydraulic control circuit 21 is different will be explained based on FIG.

In this embodiment, the opening pressure of the IJ valve 33 explained in the first embodiment is not controlled by the computer 69, but is set to a constant control pressure by the spring 34, so that the discharge port of the vane pump 20 is kept at a constant pressure. The suction and discharge ports 22, 25 and 23 of the trap vane pump 20 are closed with controlled pressure.
．． An auxiliary oil passage 52.53 having an orifice 50.51 serving as a throttling device is provided between the IJIJ valve 55 and the hydraulic control function of the IJIJ valve 55. The relief valve 3 and the orifice 50 and 51 form a hydraulic control means.

That is, the sub-oil passages 52 and 53 normally have orifices 50.51 that adjust the oil flow within the sub-oil passages 52 and 53;
When the rotation speed difference between the first rotation shaft and the second rotation shaft is small, the flow of oil into the auxiliary oil passages 52 and 55 is small, but the rotation speed difference increases and the discharge pressure of the vane pump 20 increases. When r becomes higher than the oil flow resistance of the orifice, oil flows to the auxiliary oil passages 52 and 53 even if it does not reach the set control pressure of the relief valve 5, and the torque corresponding to the difference between the two rotational speeds is applied to the second
The hydraulic pressure is transmitted to the rotating shaft and works to adjust the hydraulic control function of the relief valve 33.

When the hydraulic control circuit 21 is configured in this way, the rotor 2
Regardless of the relative rotation direction between cam ring 0a and cam ring 2Qb, the difference in rotational speed between the front and rear wheels is small.

Due to the discharge pressure of the vane pump, the oil flows through the auxiliary oil passages 52 and 53 against the flow resistance of the orifice and escapes to the suction port.

Torque corresponding to the rotational speed difference is transmitted to the rear wheels 16. On the other hand, when the rotational speed difference between the two is large, the oil reservoir 30 communicates with the suction port only when the discharge pressure exceeds the set value of the spherical valve body 36 of the relief valve 33. .This state is the same as when the orifice is not used (in other words, when the auxiliary oil passages 52 and 53 are not used).
The relationship between the rotational speed difference of the rear wheels and the discharge pressure is shown in the characteristic curves a and b in Figure 7, which show that the discharge pressure is lower when an orifice is used (however, the second curve a shows the characteristic curves a and b shown in Figure 7). (B shows the characteristic curve when the orifice is not used.) In such a four-wheel drive drive coupling device 13, the discharge pressure is maintained at a constant value by the relief valve 36, and the orifice is An auxiliary oil passage is provided.

Even if the rotation difference is small, if the rotation difference exceeds a certain value, the torque corresponding to the one rotation difference is transmitted to the rear wheels. As the accumulation increases, the 1-rotation speed difference is not that large (/), except for the disadvantage that a large amount of transmission is transmitted to the rear wheels regardless of the difference in speed between 2-revolutions.

Next, a fifth embodiment will be explained based on FIG.

This embodiment is based on the auxiliary oil passage 52° 53 of the fourth embodiment shown in FIG.
In place of the orifices 50 and 51 inside, a throttle device 55 having the structure shown in FIG. 8 is arranged, and the construction of the hydraulic pump 20 is the same as that shown in FIG. 6. This throttle device 55 is connected to the auxiliary oil passage 52 between the discharge port and the suction port of the hydraulic pump.
Located in 53.

A tire flam 59 to which a needle valve 60 is attached is provided via a spring 58 in the case 7 and the puffer 5 disposed between the oil passage on the discharge port side and the oil passage on the suction port side. A manifold negative pressure transmission port 62 that communicates with the intake manifold portion and transmits manifold pressure is opened. Squeezing device 55 with this structure
This is because as the engine torque increases, the manifold negative pressure decreases and the orifice diameter becomes smaller.

Leave the device closed and open to some extent. On the other hand, when the load on the second engine becomes smaller, the oil passage is opened further and the amount of slip knobs on the front and rear wheels is increased. When the load on the engine increases, the driving force also increases.

Make the orifice of the oil passage small and drive it with four wheels.

Furthermore, a sixth embodiment with a different hydraulic control circuit 21 will be described based on FIG.

Orifices 50°5 in the auxiliary oil passages 52, 53 shown in FIG.
The construction of the hydraulic pump 20 is the same as that shown in FIG. 6, except that a throttle device 65 having the structure shown in FIG. 9 is arranged in place of the pump 1. This throttle device 65 is arranged in the auxiliary oil passages 52 and 53 between the discharge port and the suction port of the hydraulic F valve. , a transmission port 67 for transmitting the oil pump discharge pressure of the power steering of the steering wheel, a transmission port 68 for transmitting the manifold negative pressure, and the suction side passage 56 are open, and the manifold negative pressure transmission port 68 of the Goo Song 6B and the oil , −↑2
A piston 70 is disposed between the pump discharge pressure transmission rod 67 via a spring ring 69, and is housed so as to be movable up and down by the discharge pressure of the oil pump and the negative pressure of the manifold.
A needle valve 71 is provided at the lower end of the oil passage 56 and is arranged to freely open and close the discharge port of the oil passage 56.

When the throttle device 65 with this structure is used, the higher the steering angle, the higher the oil pressure in the puff steering, so the needle valve 71 moves back, the oil passage opens wide, and the difference in rotation between the front and rear wheels is reduced. Acceptable dog-shape, 1 when front and rear wheels are running straight
When the rotation difference is large, torque is transmitted without allowing the rotation difference.

Furthermore, by introducing manifold negative pressure into the transmission port 68 and linking it with the engine torque, it is possible to appropriately switch the front and rear wheels to four-wheel drive depending on the engine torque and the steering angle.

However, since there is a significant pressure difference between the manifold negative pressure and the oil pressure of the /Quastea 1 nong, it is necessary to use a fairly strong spring 69.

In addition, means for variably restricting the flow depending on driving conditions may be used, such as closing or opening the orifice diameter depending on the magnitude of brake oil pressure, or narrowing the orifice diameter when the accelerator is off, depending on the accelerator off operation. A similar purpose can be achieved by

Next, in FIG. 10, the discharge pressure of the bomb 20 is used as a biasing mechanism for the vane 81 of the vane pump 20.
A seventh embodiment will be described.

Components equivalent to those described in the first embodiment are designated by the same reference numerals, and description thereof will be omitted.

The vane pump 20 as a hydraulic pump has a large number (eight in this case) of holes 80 formed at equal intervals in the circumferential direction on the outer peripheral surface 20c of the rotor 20a. Each has an inner circumferential surface 2. of the cam ring portion 20b. oeKffl can be contacted...-n 81 is inserted (
・Ru.

The vane 81 of the vane pump 20 is constantly biased toward the inner peripheral surface 20e of the slotted portion 20b by a hydraulic pressure supply mechanism M as a biasing mechanism. A ring-shaped recess 83 is formed which communicates with the bottom (inner diameter side part) 80a of the piston 80. connected to the pressure accumulator 85
The oil passage 84 is connected to the oil passage 40, and the oil passage 84 is connected to the oil passage 40 (and p- Even if the rotational difference between the cam ring 20a and the cam ring 20b decreases and the oil pressure decreases, even if the check puff 86 is closed, high pressure hydraulic oil is stored in the pressure accumulator 36. ~--] 81 slides in close contact with the inner circumferential surface 20e of the cam ring portion 20b.

Therefore, the vehicle stops and the rotor 20a and cam ring 20
Even if b and b do not rotate, the vane 81 is always urged in the projecting direction, so that the connection function of the b-720 is maintained at a sufficiently high level.

The drive coupling device for four-wheel drive connects the four wheels shown in Figure 1.
It is not limited to the position of the configuration diagram of the drive device, but
The configuration diagram of the 8th embodiment of the four-wheel drive system shown in FIG. The second rotating shaft 108 that transmits driving force from the dry gear 104 to the rear wheels 106 is directly driven, and the rear wheels 106 are driven via a differential device 109 for the rear wheels 106. On the other hand, the driving force transmitted from the drive gear 104 is transmitted to the first rotating shaft 114 (C) which transmits the driving force to the front wheels 112 via the four-wheel drive drive coupling device 110.
The front wheels 112 are driven via a differential gear 116 for the second vehicle. From the above schematic configuration of the vehicle's drive system, in the case of sudden acceleration, the rear wheel load increases, so the grip limit torque of the rear wheels increases, most of the engine torque is received by the rear wheels, and the rear wheels 4 with the front wheel by the amount that exceeds the Grimb limit of
The engine torque can be received through the wheel drive drive coupling device 110, +l';/'71)l-
'Capacity can be reduced. In addition, engine torque can be applied directly to the rear wheel side where the grip limit torque is large, which has the effect of improving acceleration performance.

Next, a ninth embodiment in which the hydraulic pump is a gear pump will be described with reference to FIGS. 12 to 14.

As shown in FIG. 12, a gear pop 120 which is a hydraulic pump and a hydraulic control circuit 12 attached thereto.
The gear pump 120 consists of cylindrical holes 121a, 121b formed in the housing 122,
Buon + Ngya 123 and Sun Gear 12 in 12Ic
4 and c/% together to form two pumps,
External teeth 125 are formed on the outer periphery of the gear 122 to transmit driving force from an engine (not shown).

One side of the housing 122 has a suction and discharge port 126°12.
7.128, 129, and a casing 153 in which an oil passage 130 is formed, and a first cover 165 on the other side of the housing 122, and a second cut -136° on the outside of the first cover 135 and a holt 140. are collinear with each other. A spline 141 is formed on the inner circumferential surface of the end of the second cover 136, and the second cover 136 is spline-coupled to a first rotating shaft 146 that transmits driving force to the front wheels. Driving force is transmitted from the first rotating shaft 143 to a front wheel side differential device 147 through a first rotating shaft thousand wheel portion 145 .

Also, the rotation is the same as the rotation center line of the sun gear 124.

The first cover 135 .is coupled to the sun gear 124 with a center line. A second rotating shaft 149 is provided that freely passes through the first rotating shaft 143 and transmits driving force to the rear wheels.

151, 152. 153. 154 are each -
gear number 1 in the transmission ring.
It supports 20 mag.

In this hydraulic pump, when relative rotation occurs between the first rotating shaft 143 and the second rotating shaft 149, as in the case of the Hen Pump, the difference between Sanki 1-124 and Hi=-1>-=1-' By functioning as a gear pump and blocking the discharge port, the sun gear 124 and pinion gear 123 become integrated, and the housing 122 and the sun gear 124 rotate together.

The hydraulic control circuit 121 is shown in FIG.

The first oil passage 15 which communicates the suction and discharge ports 126 and 128 of each gear pump and communicates with the oil reservoir 152 via the check valve 150 communicates the suction and discharge ports 127 and 129 to form a check valve. A second oil passage 156 communicating with the oil reservoir 152 via the oil reservoir 155 is formed, and a first relief valve 157 that only allows flow from the first oil passage 155 to the second oil passage 156-; Road 156 1st oil road 1
A second relief valve 158 is provided that allows only the flow of 53-. First relief valve 157. Second relief valve 1
Each of the valve bodies 162Vi is biased by a spring 161, and the opening pressure of each relief valve is controlled by the snow link 161.

The first relief valve 157 and the second relief valve 158 together form a switching means and an oil flow rate control means.

The four-wheel drive drive coupling device using the gear pump described above has the same functions and effects as those of the vane pump described above.

In the above embodiment, examples of a vane pump and a gear pump are shown as hydraulic pumps, and the vane pump is also explained as a balanced type with four suction and discharge ports, but depending on the amount of driving force transmitted, it may be possible to have two suction and discharge ports. 9 Other types of hydraulic pumps such as trochoid pumps, high volume pumps, axial and axial and axial pumps can also be used with 2 rotational speeds. The amount of oil discharged changes according to the difference./'J type model.

That's fine. In addition, the transmission is automatic, 7/7,
The control is not limited to hydraulic or duty control, but may be mechanically controlled (・).

Furthermore, it is suitable not only for 4-wheel drive vehicles, but also for power transmission between the front wheels and rear wheels of 6-wheel drive vehicles, and for vehicles with front two-axle drive. It can also be used for power transmission between the front and rear wheels of a vehicle with two rear axles, and for power transmission between the front and rear wheels of a rear two-axle drive vehicle. As specifically explained with examples, according to the present invention, the first rotating shaft that transmits driving force to the front wheels and the second rotating shaft that transmits driving force to the rear wheels are driven according to the rotational speed difference between them. The static hydraulic pressure is used to transmit the driving force to obtain a four-wheel drive state, and the first rotation shaft and the second rotation shaft Since the discharge port and suction port are automatically switched according to the relative rotation direction with the shaft, 4-wheel drive can be achieved without any operation, making it suitable for tight corner braking of part-time 4-wheel drive vehicles. It is possible to eliminate problems such as phenomena and the complexity of driving operations, and it can also be made smaller and lighter than the center differential conventionally equipped on full-time four-wheel drive vehicles.
Furthermore, the structure is simple and inexpensive.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the four-wheel drive drive coupling device of the present invention, and FIG. 1 is a schematic configuration diagram. Figure 2 is a detailed sectional view, Figure 5 (b) is an explanatory diagram of oil flow, Figure 4 is a cross-sectional explanatory diagram showing the second embodiment, and Figure 5 is a cross-sectional diagram showing the fifth embodiment. Explanatory diagram. FIG. 6 is a cross-sectional explanatory diagram showing the fourth embodiment, and FIG. 7 is a difference in front and rear wheel rotational speeds versus discharge pressure between the fourth embodiment shown in FIG. 6 and the case without sub-oil passages 52 and 55. 8 is a cross-sectional explanatory diagram of the fifth embodiment showing another aperture device, FIG. 9 is a cross-sectional explanatory diagram of the sixth embodiment showing another aperture device, and the tenth
The figure is a cross-sectional explanatory diagram showing the seventh embodiment, FIG. 11 is an explanatory diagram of the eighth embodiment showing a modification of the overall configuration, and FIG. 12 is a cross-sectional diagram of the ninth embodiment showing another soil/build configuration. 13 is an explanatory cross-sectional view taken along the line AA in FIG. 12, and FIG. 14 is an explanatory diagram showing the hydraulic control circuit of the ninth embodiment. 1.101...Horizontal ennon, 2,102...Transmission, 9,142...Front wheel, 10. +47...Differential gear for front wheels, 11,144,146...First rotating shaft. 13...4-wheel drive drive coupling device, 14,108°1
49...Second rotating shaft, 16,406, rear wheel, 17°1
09-・Differential device for rear wheels, 20...-1-no pump. 20a... p-ta, 20b... cam ring, 21.
... Hydraulic control circuit, 22, 23, 24.25 ... Suction discharge port, 26.27 ... First and second oil passage, 30.
...Oil reservoir, 33..Relief valve, 66..Piston. 57...Orifice, 38.44...Nonoid valve. 69... Computer, 40... Switching L 50,
51... Orifice, 52.55... Secondary oil passage, 55.6
5... Squeezing device, 120... Gear pop, 122.
・Housing, 123...Pinion gear, 124...
Sangiya agent [7,' −:, f, −mar,,,:
, , , −= , r′. Figure 1 Figure 2 Figure 3 Feather fir Figure 6 Figure 9 Shi1 40
Figure 2 Figure 1 I Figure f Figure A Figure 13 Figure 14

Claims (1)

[Claims] The first rotary shaft transmits driving force to the front wheels and the second rotary shaft transmits driving force to the rear wheels. A hydraulic pump having a suction and discharge port and in which the flow of oil is switched from one side of the suction and discharge port to the other depending on the relative rotational direction of the first rotation shaft and the second rotation shaft; A power transmission device for a vehicle, comprising: a hydraulic control circuit having a hydraulic control means disposed in an oil passage communicating one and the other and controlling hydraulic pressure discharged from the hydraulic pump.