JP2572076B2 - Input gear mount case for power transmission device for four-wheel drive vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to a power for a four-wheel drive vehicle based on a front-mounted front engine / front-wheel drive (hereinafter referred to as FF). More specifically, the present invention relates to an input gear mount case in a transmission device, more specifically, a front differential device supported inside a support case and having an input gear fixed externally, and a wet differential multi-plate clutch arranged coaxially with the device. And a split-structure input gear mount case that houses the hydraulic actuator and the hydraulic actuator.

(B) Conventional technology Recently, there have been proposed various systems for a four-wheel drive vehicle by adding a transfer unit to a power transmission device of an F / F vehicle. In addition to storing the differential device, the differential control device of the center differential device including a wet friction multi-plate clutch and its hydraulic actuator is housed so as to cover the device and coaxially with the device, and by operating the differential control device. In some cases, the driving force of the engine transmitted from the input gear is appropriately distributed to the front wheels and the rear wheels according to the situation. In this case, the input gear mount case fixes the input gear. And one of the split case pieces having a flange portion, and a flange portion at one end that is coupled to the flange portion of the one split case piece. In addition, the outer friction plate of the wet friction multi-plate clutch and a large-diameter portion having a housing portion for a hydraulic actuator and a second divided case piece having a small-diameter sleeve portion toward the other end side. ing.

(C) Problems to be Solved by the Invention However, in the input gear mount case having the above-mentioned two-part structure, the other divided case piece has a structure that is long in the axial direction, and a wet friction multi-plate clutch is provided therein. The outer friction plate and the hydraulic actuator are both housed, so it is difficult to maintain the concentricity between the large diameter portion and the sleeve portion during the processing, and the outer friction plate of the clutch is attached at the large diameter portion. Processing of splines is difficult. Further, when performing spline processing, it is necessary to form a cutter relief groove on the back side of the spline. Therefore, the number of friction plates of the wet multi-plate clutch is reduced by the relief groove, and the torque capacity of the clutch is reduced.

Therefore, an object of the present invention is to provide an input gear mount case in a power transmission device for a four-wheel drive vehicle in which the input gear mount case is divided into three parts and the above-mentioned problem is solved. It is.

(D) Means for Solving the Problems The present invention has been made in view of the above circumstances, and, for example, as shown in FIG. 1, an input gear (1) is fixed externally and an internal , A differential friction device (3), a wet friction multi-plate clutch (26) coaxially disposed with the differential device (3), and a hydraulic actuator (27) thereof
In the input gear mount case (2) in the power transmission device (U) for a four-wheel drive vehicle, the input gear mount case (2) includes a substantially disc-shaped end case portion (2a), A substantially cylindrical torso case portion provided with a connection portion (2b ₂ ) of the wet friction multi-plate clutch (26) with the outer friction plate (26a) at the inner periphery so as to penetrate the inner periphery in the axial direction ( Two
b) and a sleeve part (2c) having an annular cylinder part (2c ₁ ) for one end of a hydraulic actuator (27). The end case part (2a) Flange (2a
₁ , 2b ₁ ), and the input gear (1) and the end case portion (2) are provided through these flange portions (2a ₁ , 2b ₁ ).
a) is fixed to one end of the trunk case part (2b), and the outer peripheral side of the annular cylinder part (2c ₁ ) is inserted into the inner peripheral side of the other end of the trunk case part (2b). Is what you do.

(E) Function Based on the above configuration, the input gear mount case is divided into three parts: an end case part, a body case part, and a sleeve part, so that each part can be made smaller, lighter, and simpler in shape. Therefore, the processing of these members can be facilitated, and the processing accuracy can be improved by eliminating the deviation of the processing machine. Further, in the body case portion, a connection portion (spline) provided on the inner peripheral side of the substantially cylindrical body case portion with the outer friction plate is formed so as to penetrate the inner peripheral portion in the axial direction. Therefore, when the connecting portion is processed, it is possible to easily perform a cutting process that penetrates the inside of the body case portion in the axial direction, for example, a broaching process or the like. Furthermore, similarly, since the connecting portion is penetrated, there is no need to form a cutter escape groove, and
Although the size is the same as the conventional one, the length of the connecting portion to which the friction plate is connected can be lengthened. In addition, in the sleeve portion, the annular cylinder portion for the hydraulic actuator can be integrally formed with one end portion of the sleeve portion, so that workability and processing accuracy can be improved.

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

As shown in FIG. 1, a full-time type power transmission device U for a four-wheel drive vehicle with a front-mounted engine before a vehicle has an input gear 1 that is transmitted from an engine (not shown) via a torque converter and an automatic transmission. The input gear 1 is fixed to a gear mount case 2. The input gear 1 is fixed to the outer periphery of the mount case 2 and is supported by a support case 9 by tapered roller bearings 9a and 9b. Inside the mount case 2, a front differential device 3 and a differential control device 10 are provided. It is stored.
Further, the front differential device 3 has a front differential case 3c rotatably supported by two needle bearings 11a and 11b in the mount case 2, and the differential case 3c includes a plurality of pinions for supporting a pinion 3p. The shaft 3d is vertically supported to form a carrier, and left and right side gears 3a, 3b extend in the left and right direction and are rotatably supported, and each of the side gears 3a, 3b has a left and right front axle 8l, 8r are connected so as to be able to transmit power.

Also, on the right side of the input gear mount case 2, that is,
A transfer case 13 that can be divided into two parts, left and right, is attached to the rear of the engine.
Inside, a transfer unit 15 is mounted coaxially with the input gear mount case 2 and the front differential device 3. The transfer unit 15 has a ring gear mount case 16 and the ring gear mount case 16
Can be divided into two parts, left and right, and integrally supports a transfer drive gear 17 for driving the rear wheel composed of a hypoid gear, and is rotatably supported by a transfer case 13 via a pair of tapered roller bearings 19, 19. Have been. The gear 17 has a pinion shaft 20
A transfer driven gear 21 composed of a hypoid gear formed at all times is always meshed with the pinion shaft.
Numeral 20 is rotatably supported by an extension case 24 extending rearward via tapered roller bearings 24a and 24b, transmitted to a universal joint 25 via a spline portion 20a, and is provided with a propeller shaft and a rear differential (not shown). Power is transmitted to the left and right rear axle shafts via a device. On the other hand, a center differential device 18 is disposed in the ring gear mount case 16, and the center differential device 18 includes a differential carrier 18c having an open end. Further, the differential carrier 18c is connected to a sleeve portion 2c extending from the input gear mount case 2, and the opposite side of the connection boss portion 18c 'is open to an open end. The connecting boss 18c 'is rotatably supported by the ring gear mount case 16 with needle bearings 23, 23 interposed therebetween. A pinion shaft 18d supporting a pinion 18p is attached to the differential carrier 18c, a right side gear 18b is directly spline-coupled to the ring gear mount case 16, and a left side gear 18a is connected to the differential carrier 18a. linked to the differential case 3c of the front differential 3 through a boss portion 18c 'fitted within and sleeve portion 3c which is fitted on the right front axle shafts 8r _1'.

Further, a spline joint 22 is fitted only slidably on a spline formed at the end of the sleeve portion 2c of the input gear mount case 2, and the spline joint 22 is operated in the axial direction by an operation lever (not shown). The mechanism is switched between a lock position (see the upper half of the figure) that engages with a spline formed on the sleeve portion of the ring gear mount case 16 and a release position (see the lower half of the figure) that disengages the mechanical differential lock mechanism. doing. The mechanical differential lock mechanism is normally in a release position, but is switched to a lock position when a tire is placed on a roller at a service factory or the like to perform various inspections.

Further, the differential control device 10 is disposed in the input gear mount case 2 provided so as to cover the front differential device 3 and coaxially with the device 3, and includes a wet friction multi-plate clutch 26 and a hydraulic actuator thereof. Consists of 27. The clutch 26 has an outer friction plate 26a connected to the mount case 2 and an inner friction plate 26b connected to the differential case 3.
c, and these friction plates are pressure-controlled by a hydraulic actuator 27. The hydraulic actuator 27 includes a first piston 28 and a second piston 2 which are stored in a cylinder formed in the mount case 2 in an oil-tight manner.
9, and a reaction plate 30 located between the two pistons and arranged in an oil-tight manner. These pistons are such that the first piston 28 abuts the outer peripheral flange of the second piston 29, and The reaction force plate 30 is in contact with the cylinder end surface to form a double piston. The transfer case 13 is provided with a valve unit 31 for the differential control device 10. The control oil pressure from the unit 31 is supplied to the first piston 28 of the hydraulic actuator 27 through a pipe 32 and oil passages 33 and 35. And the second piston 29.

Further, a lubricating oil supply hole 39 is formed in the support case 9, and the lubricating oil supplied from the supply hole 39 is supplied to a sleeve portion.
Needle bearings 11a, 2 through holes 40 formed in 2c
Lubricate 3,23 etc. and discharge holes 41 formed in case 13
And the lubricating oil guided to the front differential device 3 through the needle bearing 11a is introduced into the gear mount case 2 through the gap a and accumulated in the case 2, and the multi-plate clutch 26 A throttle hole 42 formed in the inner surface of the case 2 by lubrication in an oil bath state.
It is to be discharged from. At this time, the needle bearing 11a forms an orifice for appropriately regulating the lubricating oil flow rate according to the number of needles and the like.
The amount of lubricating oil introduced into the inside is controlled to a predetermined amount. Furthermore,
Lubricating oil introduced between b and 'axle shaft 8r and the sleeve portion 3c ₁ from the hole 43 formed in the' sleeve portion 3c ₁ is supplied into the front differential case 3c through the thrust washer, in the case 3c After the lubricating oil overflows in the chamber C formed in the chamber C, the lubricating oil lubricates the thrust washer between the differential case 3c and the mount case 2,
Some lubricate the needle bearing 11b. On the other hand, the lubricating oil from the lubricating oil supply hole 44 formed in the support case (axle housing) 9 on the left axle shaft 8l side
The lubrication hole 45 provided in the axle shaft 8l and the sliding contact surface of the differential case 2 are lubricated.

Oil seals 50, 51 are provided at both end portions of the gear mount case 16, that is, outside the tapered roller bearings 19, 19, so that these oil seals 5 are provided.
0,51, gear mount case 16, transfer case 1
3. A closed chamber D defined by the extension case 24 and an oil seal 54 at the tip of the case is formed, and each component in the chamber D contains an extreme pressure additive sealed in the chamber D. The lubricating oil is lubricated in a system different from the above lubrication system.

The input gear mount case 2 described above is
As shown in detail in the figure, the end case 2a, the trunk case portion 2b and the sleeve portion 2c are divided into three parts,
The end case portion 2a has a substantially disk shape, and a flange portion 2a1 for fixing the input gear ₁ is formed on an outer peripheral portion thereof, and a left front axle shaft 8l is formed inside the center portion thereof. supported by cylindrical projection 2a ₂ which is rotatably supported by the support case 9 via a bearing 9a outside is formed. Further, the body case portion 2b has a substantially cylindrical shape, and a flange portion of the end case portion 2a is provided at one end thereof.
Flanged portion 2b ₁ being joined formed 2a _1, spline 2b ₂ successive so as to move the outer friction plate 26a of the wet friction multi-plate clutch 26 in the axial direction of the body casing portion 2b in its inner peripheral portion Are formed. The spline 2b ₂ is formed to penetrate the inner peripheral portion in the axial direction. That is,
When processing the body case part 2b as a single unit, the spline 2b
_Since both ends of ₂ are openings, cutting work that penetrates the inside of the trunk case 2b, for example, broaching, becomes easy, and the workability and processing accuracy are remarkably improved compared to the conventional processing from one side. Can be improved. Furthermore, the sleeve portion 2c is not configure a two-stage cylindrical shape, one end side constitutes an annular cylinder portion 2c ₁ which accommodates the result and the piston 28, 29 from the inner diameter wall and an outer diameter wall, and during the outer diameter wall of the cylinder portion 2c ₁ is between the cylinder case portion 2b and the other end is inserted and bonded is formed for example on the annular stepped portion 2b ₃ to a, also the other end sleeve portion 3c ₁ and transfer case 13 constitute a sleeve portion 2c ₂ extending. And
The end case portion 2a and the trunk case portion 2b are brought into contact with the flange portion 2a ₁ and the flange portion 2b ₁ and the flange portion 2a.
_The input gear 1 is fitted / arranged on _one side, and they are joined together by tightening them with bolts 12. The body case portion 2b and the sleeve portion 2c are connected to the step portion 2b ₃ of the body case portion 2b. after inserting the outer diameter wall of the annular cylinder portion 2c ₁ of the sleeve portion 2c within, is coupled by welding, the input gear mount casing 2 is adapted to be assembled. Further, a ring gear 56 for a speed sensor is mounted on the outer peripheral surface of the annular cylinder portion 2c ₁ in the sleeve portion 2c by using a step portion with the trunk case portion 2b, and the gear 56 is a snap ring.
It is stopped at 57.

 Next, the operation based on the above structure will be described.

The rotation of the engine is appropriately shifted by the automatic transmission and transmitted to the input gear mount case 2 via the input gear 1. During normal driving, the valve unit
31 is connected and the hydraulic pressure based on the line pressure is
Acting on both pistons 28 and 29 of the hydraulic actuator 27 via the oil passages 32 and the oil passages 33 and 35, the wet multi-plate clutch 26 is connected at a predetermined pressure. Therefore, in the center differential device 18, the differential carrier 18c and the left side gear 18a are coupled with a predetermined coupling force, and the differential is limited by the predetermined regulating force. Accordingly, when the frictional force between the road surface and the tire is smaller than the above-described regulation force, for example, on a road surface having a small friction coefficient such as a snowy road or a dirt road, the center differential device is determined based on the pressing force of the clutch 26.
18 is in a state close to direct connection, is transmitted to the differential case 3c of the front differential device 3 via the friction clutch 26 and the center differential device 18 that rotates integrally, and is further distributed to the left and right side gears 3a, 3b via the pinion 3p. Ring gear fixed to the center differential device 18 while driving the front left and right wheels
17 and transmitted to the pinion shaft 20 via the gear 21,
Further, torque is distributed by the rear differential device to drive the left and right rear wheels. Further, when the frictional force between the road surface and the tire is substantially balanced with the regulating force by the clutch 26, for example, when traveling on a paved road at a relatively high speed, the tire slip is reduced in relation to the road surface friction coefficient. The clutch 26 is pressed while sliding so as not to occur. That is, the center differential device 18 distributes the torque to the front and rear wheels while absorbing the rotation difference between the front and rear wheels in a state where the torque distribution to the front and rear wheels is biased to approach 50:50.

When the steering angle is greatly reduced at low speeds such as when the vehicle is put in a garage, a difference in rotation occurs between the front and rear wheels. In this case, however, the throttle opening is small and the hydraulic pressure based on the line pressure is also low. The pressure is also weak, and the engaging force of the friction clutch 26 of the differential control device 10 is also weak. Therefore, in order to allow the relative rotation of the left and right side gears 18a, 18b of the center differential device 18 based on the rotation difference between the front wheels and the rear wheels, the friction clutch 26 controls the differential of the center differential device 2 while sliding, and It transmits torque to the front and rear wheels while preventing the occurrence of the braking phenomenon.

In addition, when the vehicle travels at a relatively high speed on a road where a steep curve such as a mountain road continues continuously, the driver can operate the valve unit 31 to the off position as desired. In this state,
The supply of the line pressure to the hydraulic actuator 27 of the differential control device 10 is cut off, and the friction clutch 26 is released. Then, the rotation of the mount case 2 is transmitted to the differential carrier 18c of the center differential device 18 via the sleeve portion 2b, and is further transmitted from the differential pinion 18p to the left and right side gears 1c.
It is branched and transmitted to 8a and 18b. And the left side gear 18a
The rotary is transmitted to the differential case 3c of the front differential 3 through a sleeve portion 3c ₁ ', is transmitted further side gears 3a of the left and right from the differential pinion 3p, the left and right front axle shafts are branched-transmitted to 3b 8l, the 8r . On the other hand, the rotation of the right side gear 18b is transmitted to the gear mount case 16 which is spline-coupled to the gear, further transmitted to the pinion shaft 20 via the rear wheel driving ring gear 17 and the gear 21, and the propeller shaft (not shown) It is transmitted to the left and right rear wheels via the rear differential device.

In the above operation, the input gear mount case 2 is divided into three parts, namely, an end case part 2a, a body case part 2b, and a sleeve part 2c. Since it is manufactured and the number of multi-plate clutches 26 is large, a differential control device comprising a wet friction multi-plate clutch 26 and a hydraulic actuator 27
In 10, the operation of the clutch 26 in the body case portion 2b becomes smooth, and the operation of the actuator 27 in the sleeve portion 2c becomes smooth.
2b and the sleeve portion 2c are advantageously welded on the outer peripheral surface in terms of strength, so that the operation of the differential control device 10 itself is stable and accurate, and in operation, the front of the four-wheel drive vehicle In addition, appropriate torque distribution corresponding to the driving condition to the rear wheels is always preferably performed in a stable state. In addition, since the input gear mount case 2 is constructed with good concentricity by assembling the parts manufactured with high precision, the case 2 is concentric with the adjacent support case 9, front differential device 3, center differential device 18, and the like. It is well assembled and transmits torque very smoothly during operation.

In the above-described embodiment, the differential control device 10 is used in a constantly operating state. However, it is needless to say that the differential control device 10 may be used as a so-called differential lock mechanism which is always in a non-operating state and operates only when necessary. is there. The first piston 28 and the second piston 28 of the hydraulic actuator 27 comprising a double piston
The hydraulic pressure consisting of one system is supplied to the piston 29, and it is used as a mere booster.However, it is configured so that the hydraulic pressure individually controlled by a separate oil path is supplied to enable fine slip control. Is also good. Further, the full-time four-wheel drive having the center differential device has been described. However, the present invention can also be applied to a part-time four-wheel drive in which a clutch is interposed in a power transmission system on the rear wheel. The clutch 26 is a clutch that transmits power to the rear differential device only when necessary.

(G) Effect of the Invention As described above, according to the present invention, the input gear mount case is divided into three parts: an end case part, a body case part, and a sleeve part. Since the weight can be reduced and the shape can be simplified, the processing of these members can be facilitated, and the processing accuracy can be improved by eliminating blurring of the processing machine. Therefore, concentricity between the body case portion and the sleeve portion after assembly can be ensured. Further, in the body case portion, a connection portion (spline) provided on the inner peripheral side of the substantially cylindrical body case portion with the outer friction plate is formed so as to penetrate the inner peripheral portion in the axial direction. Therefore, it is possible to easily perform a cutting process that penetrates the inside of the body case portion in the axial direction, for example, a broaching process, when processing the connecting portion, compared to a cutting process in which one is closed. As a result, workability and processing accuracy can be remarkably improved. Furthermore, since the connecting portion is also penetrated, there is no need to form a cutter escape groove, and the length of the connecting portion in the axial direction is increased by that much, so that the friction plate has the same size as the conventional one. The transmission torque capacity can be increased by increasing the number of sheets. In addition, in the sleeve portion, the annular cylinder portion for the hydraulic actuator can be integrally formed at one end of the sleeve portion,
Workability and processing accuracy can be improved. In particular, the operation after the power transmission device is assembled can be stabilized by improving the concentricity and the inner surface accuracy of the annular cylinder portion.

The configuration of the present application is not only capable of improving the workability, the processing accuracy, and the productivity of each member as described above, but also the smooth torque transmission by improving the processing accuracy of the constituent members of the input mount case. It is possible to relatively easily improve the performance of the entire power transmission device.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an input gear mount case according to the present invention, and FIG. 2 is a sectional view showing a power transmission device for a four-wheel drive vehicle to which the present invention is applied. 1 Input gear 2 Input gear mount case 2a
… End case part, 2a ₁ … Flange part, 2b …… Body case part, 2b ₁ …… Flange part, 2b ₂ …… Connection part (spline), 2c …… Sleeve part, 2c ₁ …… Circular cylinder part ,
3 front differential device, 9 support case, 10 differential control device, 18 center differential device, 26 wet friction multiple disc clutch, 26a
Outer friction plate, 27 ... Hydraulic actuator, 56 ... Ring gear for speed sensor.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Fumitomo Yokoyama 10 Takane, Fujiimachi, Anjo, Aichi Prefecture Inside Ishin Warner Co., Ltd. (72) Inventor Masaharu Tanaka 1st Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Vehicle Stock In-company (72) Inventor Kojiro Kuramochi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (56) References JP-A-62-80354 (JP, A)

Claims (2)

(57) [Claims] An input gear is fixed externally, and a differential device, a wet friction multi-plate clutch coaxially disposed in the device, and a hydraulic actuator thereof are housed therein. In the input gear mount case in the transmission device, the input gear mount case includes a substantially disc-shaped end case portion, and a connection portion between an outer friction plate of the wet friction multi-plate clutch and an inner periphery portion. A substantially cylindrical body case portion provided so as to penetrate in the axial direction, and a sleeve portion provided with an annular cylinder portion for a hydraulic actuator at one end; A flange portion is provided at one end of the case portion, and the input gear and the end case portion are fixed to one end of the body case portion via these flange portions. Is, the barrel to the other inner side of the case portion, said annular cylinder portion is inserted an outer peripheral side of the input gear mount casing in the power transmission device for a four-wheel drive vehicle, characterized in that. 2. The input gear mount in a power transmission for a four-wheel drive vehicle according to claim 1, wherein said wet friction multi-plate clutch and said hydraulic actuator constitute a differential control device of a center differential device. Case.