JPH0830505B2 - Rotation sensitive joint - Google Patents

Description

The present invention relates to a driving force distribution device for a multi-wheel drive vehicle such as a four-wheel drive vehicle, a left / right wheel differential device, and a left / right wheel differential limiting device. The present invention relates to a rotation difference sensitive joint used as a motion limiting device or the like.

(Prior Art) As a prior art rotation difference type joint, for example, as described in the specification and drawings of Japanese Utility Model Application No. 62-184484 previously proposed by the present applicant, a rotor and a drive housing are used. There is a convex spherical bearing surface and a concave spherical bearing surface that are in spherical contact with each other, and allows bending motion at the joint part, and does not require a universal joint other than this rotation difference type joint, The sound and vibration performance of the vehicle is kept good by reducing the number of points and the amount of backlash.

(Problems to be Solved by the Invention) However, in such a leading joint, the rotor and the drive housing cannot absorb the axial deviation even if the bending movement at the joint can be allowed. Therefore, there remains a problem that the sound and vibration performance of the vehicle is deteriorated by the stress applied in the axial direction.

(Means for Solving the Problem) The present invention aims to solve the above-described problems, and in order to achieve this object, the present invention relates to a first rotating shaft and a first rotating shaft. A rotatable and coaxially arranged second rotating shaft; a rotor and a drive housing connected to the first and second rotating shafts; and a relative rotation between the first and second rotating shafts provided on the rotor. The plurality of driving pistons that reciprocate in the radial direction when rotating, the cam surface that is formed on the inner surface of the drive housing and that contacts the driving piston, and the flow of oil provided in the flow path that connects the cylinder chamber of the driving piston are restricted. And a rotation difference sensitive joint in which the transmission torque is controlled according to the relative rotation speed between the first and second rotation shafts. A pair of outer cylinders having a concave spherical surface that is supported slidably in the axial direction at the minimum rotation radius portion of the cam surface of the live housing and that spherically supports the convex spherical surface formed on the rotor; and the pair of outer cylinders. The means is characterized in that a cage having a connecting frame portion that is connected between the supporting portions of the driving piston of the rotor and that is connected at a recessed portion is provided.

(Operation) When the rotation difference-sensitive joint of the present invention is applied to a drive system of a vehicle, if a rotation speed difference occurs between the first rotation shaft and the second rotation shaft due to relative rotation, the orifice A hydraulic pressure is generated by the flow resistance due to, and the torque corresponding to the rotational speed difference between both rotary shafts is transmitted from one shaft to the other shaft.

When this rotation difference sensitive joint is used in a drive system of a vehicle, a power unit, a final reduction gear, or the like provided at both ends of the first rotation shaft and the second rotation shaft is mounted on the vehicle body with a rubber mount. Since the first rotation shaft and the second rotation shaft connected to the rotation-difference-sensitive joint change in bending angle, a shift also occurs in the axial direction.

However, between the rotor and the drive housing, a pair of concave spherical surfaces axially slidably supported by the minimum rotation radius portion of the cam surface of the drive housing and having a spherical surface supporting the convex spherical surface formed on the rotor are provided. Since the cage including the outer tubular portion and the connecting frame portion that connects the pair of outer tubular portions at the recessed portion formed between the supporting portions of the driving piston of the rotor is provided, the first rotating shaft and the first rotating shaft The change in the bending angle with respect to the rotation axis of 2 is allowed in the follow-up correspondence by the spherical contact of the cage, and the axial deviation is allowed in the follow-up correspondence by the axial sliding of the cage.

Therefore, even when applied to a drive system of a vehicle used at high rotation in which a change in bending angle between the first rotating shaft and the second rotating shaft and a displacement in the axial direction occur, bending is performed separately from the rotation difference sensitive joint. It is possible to suppress noise and vibration in the passenger compartment to a low level without providing a joint that absorbs the axial deviation.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In describing this embodiment, a rotation difference sensitive joint provided in an engine drive force transmission system of a four-wheel drive vehicle will be taken as an example.

 First, the configuration will be described.

As shown in FIG. 4, the rotation difference sensitive joint A1 of the first embodiment has a center differential and a driving force to the rear wheels in the middle of the rear wheel drive system of a four-wheel drive vehicle based on the front wheel drive. It is provided as a joint that also serves as a distribution control device.

The drive system of a four-wheel drive vehicle to which the joint A1 of the first embodiment is applied is, as a front-wheel drive system, an engine 1, a transmission (including a clutch) 2, a front differential 3, front drive shafts 4, 5, front drive shaft joints. 6, including front wheels 7 and 8, as a rear wheel drive system, a transfer gear train 9, a front propeller shaft 10, a rear propeller shaft (first rotation shaft) 11, a rotation difference sensitive joint A1, a differential input shaft ( Second rotary shaft) 12, propeller shaft joint 13,
It has a center bearing 14, a rear differential 15, rear drive shafts 16 and 17, a rear drive shaft joint 18, and rear wheels 19 and 20.

The front differential 3 is a differential device of front wheels 7 and 8 interposed between the final stage gear 21 of the transmission 2 and the front drive shafts 4 and 5.

The transfer gear train 9 is a drive force dividing device that takes out the engine drive force from the differential case 22 of the front differential 3 to the rear wheels 19 and 20, and is installed in the transaxle case 23 together with the transfer gear train 9 and the front differential 3. Has been.

The rear differential 15 is a differential device for the rear wheels 19 and 20 interposed between the differential input shaft 12 and the rear drive shafts 16 and 17.

 The structure of the rotation difference sensitive joint A1 will be described.

As shown in FIGS. 1 and 2, the first embodiment joint A1 includes a drive housing 30, a rotor 40, a driving piston 50, a cylinder chamber 60, a balance oil passage 70, a regulator oil passage 80, a relief oil passage 90, Accumulator room 10
0, spool valve 110, and cage 120 are the main components.

The drive housing 30 is a member that is integrally provided inside the differential input shaft 12 that is the second rotating shaft by bolting or the like, and has a cam surface that has an equal cross-sectional shape in the rotating shaft direction on its inner peripheral portion. 31 is formed.

In addition, on the side of the rear propeller shaft 11 and the differential input shaft 12 of the drive housing 30, the packing 3
Retainer plates 34, 35 are fixed via 2, 33. Further, between the retainer plate 34 and the rotor 40, a rubber boot 36 that allows bending displacement and sliding displacement and a lip seal 37 that maintains a sealing property are interposed.

The rotor 40 is disposed in the cam surface 31 of the drive housing 30 in an inserted state, and has a rotor spline portion.
A rear propeller shaft 11 which is a first rotating shaft is integrally provided with 41.

Cylinder holes 42 are formed in the rotor 40 at six positions at a position facing the cam surface 31 at equal intervals in the radial direction.

Further, convex spherical surfaces 40a and 40b are formed at left and right positions in the drawing with the cylinder hole 42 of the rotor 40 interposed therebetween.

The driving piston 50 has the cylinder hole 42.
On the other hand, the cam member provided in an oil-tight state by the seal ring 51 makes circumferential contact with the cam surface 31 at regular intervals of 60 degrees,
The cam surface 31 and the circumferential contact surface are formed on a spherical surface 50a to ensure smooth contact movement, and reciprocate when the drive housing 30 and the rotor 40 rotate relative to each other.

Although the radius of curvature of the spherical surface 50a is smaller than that of the cam surface 31, it is set larger than that of the driving ball that matches the diameter of the cylinder hole 42, the contact stress of Hertz is high, and high capacity (high torque) can be endured. I am trying.

The cylinder chamber 60 is a chamber formed between the cylinder hole 42 and the driving piston 50, and its volume changes as the driving piston 50 reciprocates.

The balance oil passage 70 is formed in the rotor 40,
In the reciprocating stroke of the driving piston 50, the cylinder chambers 60, 60 having the same phase are connected to each other, and the inclined oil passage 7
Accumulator chamber 10 via spool valve 110 by 1
This is an oil passage that can communicate with 0.

The regulator oil passage 80 connects each cylinder chamber 60 and the accumulator chamber 100 via a one-way valve 81 having a ball valve structure that allows only differential oil flow from the accumulator chamber 100 to the cylinder chamber 60. Is.

The relief oil passage 90 is provided in the accumulator chamber 100.
And the outside of the cylinder chamber 60 when the hydraulic pressure in the accumulator chamber 100 is high.
It is an oil passage that communicates with stroke 1.

The accumulator chamber 100 is a chamber for temporarily increasing and decreasing the amount of hydraulic oil by temporarily storing and discharging the hydraulic oil.
Accumulator piston 101 reciprocally provided in an oil-tight state, and the piston 101 and spring retainer 102
And a coil spring 103 which is interposed between and.

Incidentally, the accumulator piston 101 has a seal plug 10 for air and oil removal at its central portion (on the central axis).
4 is provided, and this seal plug 104 prevents rotational unbalance and enables effective air and oil removal work in a short time.

The spool valve 110 includes a cylinder chamber 60 and an accumulator chamber 100 between the inclined oil passage 71 and the accumulator chamber 100 via a predetermined orifice opening when the oil temperature is low.
A spool 111 in which an orifice land 111a and a vertical hole 111b are formed, and a bias spring 112 provided in the inner diameter portion of the spool 111. , And a shape memory alloy spring 113 provided on the outer diameter portion of the spool 111.

The upper half of FIG. 1 shows a low oil temperature which is communicated through the orifice land 111a, and the lower half of FIG. 1 is an extension of the shape memory alloy spring 113 to cut off the communication between the two chambers 60 and 100. The drive housing 30
And the rotor 40 are locked to ensure high torque transmission at high oil temperatures.

The cage 120 includes a rotor 40 and a drive housing 3
It is a member provided to allow bending and axial deviation of the propeller shafts 10 and 11 between 0 and 0.

The cage 120 includes a cam surface 31 of the drive housing 30.
A pair of outer cylinder parts 121, 122 having a concave spherical surface 120a, 120b that is slidably supported in the axial direction at the minimum turning radius portion of 31min and that also spherically supports the convex spherical surface 40a, 40b formed on the rotor 40.
And a connecting frame part 123 for connecting the pair of outer cylinder parts 121, 122 at the position of the recess 43 formed between the supporting parts of the driving piston 50 of the rotor 40. In the first embodiment, as shown in FIG. In addition, the one outer cylinder part 122 and the connecting frame part 123 are integrally formed, and the outer cylinder part 121 and the connecting frame part 123 are fixed by screws 124 to be assembled.

 Next, the operation of the embodiment will be described.

(A) When the rotational speed difference ΔN does not occur When driving straight on a dry asphalt road at low to medium speeds, and when the rotational speed difference ΔN does not occur between the front and rear wheels, the drive housing 30 Since there is no relative rotation with the rotor 40 and the driving piston 50 does not reciprocate in the radial direction, there is no transmission torque ΔT generated by the rotation difference sensitive joint A1 to the rear wheels 19 and 20, and the engine driving force is the front wheels. Front wheel drive is transmitted to only 7 and 8.

However, even when the rotational speed difference ΔN does not occur between the front and rear wheels, when traveling straight on a highway at a high speed,
A centrifugal force Fc acts on the driving piston 50 provided on the rotor 40 that rotates at a high speed as the rear wheels 19, 20 rotate, and the centrifugal force Fc causes the driving piston 50 to move.
Will be pressed against the cam surface 31, and this centrifugal force Fc
As a result, the transmission torque ΔTco is generated as shown in FIG. The centrifugal force Fc is m: mass (driving piston) r: distance from the center of rotation to the center of gravity of the mass v: rotor rotation speed, which is generated in proportion to the rotation speed v, that is, the square of the vehicle speed V.

Therefore, when traveling straight at high speed on highways, the rear wheels 1
Transmission torque ΔTco to the 9th and 20th side is generated, and it becomes a four-wheel drive state, and high-speed straight traveling stability can be improved.

(B) When the rotational speed difference ΔN occurs When the accelerator pedal is suddenly pressed to start or accelerate, or when driving on a rainy road, a snowy road, a muddy ground, or the like, the front wheels 7 that are driving wheels are used. , 8 slipped, the difference in rotational speed between the front and rear wheels △
If N occurs, drive housing 30 and rotor
Relative rotation occurs between 40 and the cam surface 31 due to this relative rotation.
The driving piston 50 circumferentially contacting with reciprocates in the radial direction, and when it is attempted to reduce the volume of the cylinder chamber 60 by moving toward the center of the rotation axis in this reciprocating motion, the flow resistance due to the orifice land 111a causes the inside of the cylinder chamber 60 to flow. Is increased, and the hydraulic pressure obtained by multiplying the generated hydraulic pressure with the pressure receiving area of the piston 50 becomes the force for pressing the driving piston 50 against the cam surface 31, and this pressing force causes the rear wheels 19,2
A transmission torque ΔT to the 0 side is generated.

As the rotational speed difference ΔN increases, the transmission torque ΔT to the rear wheels 19, 20 also increases the pressure difference across the orifice 62. Therefore, as shown by the solid line in FIG.
The transmission torque characteristic represented by a linear function curve is shown. The higher the vehicle speed V, the more the transmission torque ΔTc due to the centrifugal force is added.

It should be noted that the rotation difference sensitive joint A1 and the rear wheel 1 through the joint A1
Since the relief oil passage 90 that relieves the discharge oil at a pressure smaller than the breaking strength of the drive transmission system that transmits the driving force to 9,20 is provided, the torque up to the maximum driving torque ΔTcmax can be applied to the rear wheels 19,20.
Is input to.

Therefore, when the front wheels 7 and 8 slip, the driving force distribution is automatically controlled from the front wheel driving state to the four-wheel driving state in accordance with the slip degree of the front wheels 7 and 8, and the startability is improved. It is possible to improve acceleration and acceleration, improve running performance on rainy roads and snowy roads, and improve escape performance on muddy ground.

(C) Locking action Since the spool valve 110 that senses and opens and closes the oil temperature is used instead of the fixed orifice, when the oil temperature is low, the transmission torque ΔT is affected by the rotation difference as described above.
Is variably controlled, but when the rotation speed difference continues to occur and the oil temperature becomes high, such as when running on sand for a long time,
By the closing operation of the spool valve 110, the inflow and outflow of oil in the cylinder chamber 60 is blocked, the drive housing 30 and the rotor 40 are locked, and the heat generation effect of oil by adiabatic compression is stopped, and the oil temperature rises. In addition to being restrained, driving force distribution will be in the rigid 4WD state of four-wheel distribution, which can improve running performance.

(D) Sliding joint action As described above, when the rotation difference sensitive joint A is used as joint means and as torque transmitting means, the power unit and the rear differential 15 at both ends of the propeller shafts 10 and 11 are mounted on the vehicle body. On the other hand, since it is supported by the rubber mount, the bending angle of the rear propeller shaft 11 and the differential input shaft 12 connected to the rotation difference sensitive joint A1 changes, and a slight deviation occurs in the axial direction.

However, since the cage 120 is interposed between the drive housing 30 and the rotor 40, the change in the bending angle of the rear propeller shaft 11 and the differential input shaft 12 can be followed up within the allowable bending angle α. The axial deviation between the shafts 11 and 12 is allowed by the follow-up correspondence within the range of the slide allowable length β from the intermediate position in the lateral direction of the drawing.

Therefore, compared to the case where a joint that absorbs bending and sliding is provided separately from the rotation difference-sensitive joint A1, there is less backlash, and there is less noise and noise in the passenger compartment even when the propeller shafts 10 and 11 rotate at high speed. Vibration can be kept low.

The default bending angle of the rotation difference sensitive joint A1 is generally 2 to 3 so as not to adversely affect the sound and vibration of the vehicle.
Since the power unit and the rear differential 15 are relatively firmly supported to the vehicle body, the tolerance within the allowable bending angle α and the allowable slide length β is sufficient for practical use. .

Further, since the convex spherical surfaces 40a, 40b of the rotor 40 are not the outer diameter portion of the rotor 40 but the small diameter portion of the concave portion 43,
Since the spherical support radius is reduced, the play between the drive housing 30 and the rotor 40 can be reduced, and noise and vibration in the vehicle interior can be further suppressed from this aspect. That is, when relative rotation is suddenly generated, a high torque is transmitted, and the temperature of the hydraulic oil rises, when the spherical support radius is large, the radial expansion margin of the rotor 40 is large, and the rotor 40 burns with the drive housing 30. In order to prevent sticking, it is necessary to increase the backlash accordingly.

As described above, in the joint A1 of the first embodiment,
Cage 120 between rotor 40 and drive housing 30
Since it has a function to absorb bending change and axial deviation, it is possible to reduce the weight and cost with a decrease in the number of parts, and at the time of high rotation due to bending change and axial deviation. Also in the case of the above, a peculiar effect that noise and vibration in the passenger compartment can be suppressed to a low level is obtained.

Generally, four-wheel drive vehicles have many power transmission parts,
It is necessary to suppress sound vibration severely. In other words, there is a strong need to reduce the sliding resistance of the propeller shaft while transmitting torque.

For this reason, in the past, many used special low-sliding joints, but by using joint A1 of the embodiment, the problems of tight corner brakes and sound vibration, which are problems as a four-wheel drive vehicle, were all solved. Can be solved.

Next, the rotation difference sensitive joint A2 of the second embodiment shown in FIGS. 6 to 8 will be described.

The joint A2 of the second embodiment is the eighth gauge as the gauge 120.
As shown in the figure, both outer cylinder parts 121, 122 and the connecting frame part 123 are formed separately, respectively, and screw parts 123a, 123a are formed at both ends of the connecting frame part 123 made of a round bar, and connected to the outer cylinder parts 121, 122. Frame 123
And nuts 125 and 126 are used for fixing.

Since the other configurations and operational effects are similar to those of the first embodiment, the description thereof will be omitted here.

The embodiment of the present invention has been described in detail above with reference to the drawings.
The specific configuration is not limited to this embodiment, and even if there are design changes and the like within the scope of the present invention, they are included in the present invention.

For example, the rotation difference-sensitive joint of the present invention is not limited to the application example shown in the embodiment, but may be provided in the middle of the front wheel side propeller shaft of a rear wheel drive-based four-wheel drive vehicle.

Further, the present invention is not limited to a joint for a four-wheel drive vehicle, but can be applied to a differential limiting device between left and right drive wheels in a four-wheel drive vehicle or a two-wheel drive vehicle.

Further, in the embodiment, as the member exhibiting the orifice function, the spool valve in which the switching between the orifice opening state and the shut-off state is automatically performed is shown, but the fixed valve as described in the prior application is used. Of course, it can be applied to a joint provided with an orifice or a joint using an orifice and an on-off valve.

(Effect of the Invention) As described above, in the rotation difference sensitive joint of the present invention, between the rotor and the drive housing,
A pair of outer cylinder parts having a concave spherical surface that is supported slidably in the axial direction at the minimum rotation radius part of the cam surface of the drive housing and that spherically supports the convex spherical surface formed on the rotor; and the pair of outer cylinder parts. Since the cage is provided with the connecting frame part that connects at the concave position formed between the supporting parts of the driving piston of the rotor, it has the function of absorbing the bending change and the axial deviation, which reduces the number of parts. It is possible to reduce the weight and the cost, and it is possible to obtain the effect that the noise and vibration in the passenger compartment can be suppressed to be low even at the time of high rotation accompanied by bending change and axial displacement.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional side view taken along the line I-I of FIG. 2 showing a rotation difference-sensitive joint of the first embodiment of the present invention, and FIG. 2 is a line II-II of FIG.
FIG. 3 is an exploded perspective view showing the cage of the first embodiment, FIG. 4 is a schematic view showing an engine drive system to which the joint of the first embodiment is applied, and FIG. 5 is a joint of the embodiment. FIG. 6 is a vertical sectional side view taken along the line III-III of FIG. 7 showing a rotation-sensing type joint of the second embodiment of the present invention, and FIG. 7 is a vertical sectional front view taken along the line IV-IV of FIG. 8 and 9 are exploded perspective views showing the cage of the second embodiment. A1 …… Rotation differential joint 11 …… Rear propeller shaft (first rotary shaft) 12 …… Differential input shaft (second rotary shaft) 30 …… Drive housing 31 …… Cam surface 40 …… Rotor 40a, 40b …… Convex sphere 43 …… Concave 50 …… Driving piston 60 …… Cylinder chamber 70 …… Balance oil passage 100 …… Accumulator chamber 110 …… Spool valve 120 …… Cage 120a, 120b …… Concave spherical surface 121,122 …… Outside Cylindrical part 123 ... Connection frame part

Claims (1)

[Claims] 1. A first rotating shaft, a second rotating shaft which is relatively rotatable with respect to the first rotating shaft, and is coaxially arranged, and the first rotating shaft.
A rotor and a tribe housing connected to the second rotation shaft, a plurality of driving pistons that reciprocate in the radial direction when the first and second rotation shafts provided on the rotor rotate relative to each other, and the drive housing A cam surface that is formed on the inner surface and that contacts the driving piston, and an orifice that is provided in a flow path that connects the cylinder chamber of the driving piston and that restricts the flow of oil, and a relative rotation speed between the first and second rotation shafts. In a rotation difference sensitive joint in which transmission torque is controlled in accordance with the above, a rotor is supported between the rotor and the drive housing so as to be slidable in the axial direction at a minimum rotation radius portion of a cam surface of the drive housing and formed on the rotor. A pair of outer cylinders having a concave spherical surface for spherically supporting the formed convex spherical surface, and the pair of outer cylinders supporting the driving piston of the rotor. A rotation-difference-sensitive joint, characterized in that a cage provided with a connecting frame portion which is connected between concave portions formed between the holding portions is provided.