JPH0535444U - 4-wheel drive vehicle with center differential - Google Patents

Abstract

(57) [Summary] [Purpose] A compact vehicle speed sensor is installed near a multi-function center differential device or a hydraulic multi-disc clutch device. In a hydraulic multi-plate clutch 62 attached to a center differential device 50, a hydraulic multi-plate clutch 62 that differentially restricts and variably controls torque distribution of front and rear wheels, and a drum member 65 integrated with the rear drive shaft 20. A pulse gear 71 is formed by using a pressing member 68 that is pressably attached to the vehicle speed sensor 7 with a case-side electromagnetic pickup 72 facing the pulse gear 71.
Configure 0.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a four-wheel drive vehicle equipped with a center differential device, and more particularly, to a structure of a vehicle speed sensor mounted near a center differential device or a hydraulic multiple disc clutch device.

[0002]

[Prior Art]

 In recent years, in four-wheel drive vehicles equipped with a center differential device, in addition to providing the center differential device with a differential function and a torque splitting function to the front and rear wheels, the torque distribution of the front and rear wheels can be variably controlled, reduced or reduced. It has been proposed to use it as a speed increasing device to further improve running performance, maneuverability, stability, braking performance, and the like. When various functions are added to the center differential device in this way, multiple hydraulic multi-disc clutches and multi-disc brakes are attached, which complicates the structure and serves as a basic signal for torque distribution control to the front and rear wheels. It is desirable that the vehicle speed sensor be mounted in a compact structure using these parts.

Conventionally, as a four-wheel drive vehicle with a center differential device having the above-described multi-function, there is, for example, one disclosed in Japanese Patent Laid-Open No. 3-135838. Here, the hydraulic multi-plate clutch device attached to the compound planetary gear type center differential device is configured by arranging a plurality of hydraulic multi-plate clutches and brakes in order in the axial direction. In addition to the hydraulic multi-plate clutch device, the vehicle speed sensor is shown to have a pulse gear fixed to the rear drive shaft and an electromagnetic pickup facing the pulse gear.

[0004]

[Problems to be solved by the device]

 By the way, in the above-mentioned prior art, the vehicle speed sensor, which is one of the basic signals for controlling the torque distribution to the front and rear wheels, has a large number of parts because a dedicated pulse gear is fixedly attached to the rear drive shaft. Then, there is a problem that the structure becomes complicated and extra space is required.

The present invention has been made in view of this point, and an object of the present invention is to compactly configure a vehicle speed sensor mounted near a multi-function center differential device or a hydraulic multi-disc clutch device.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a center differential device having a torque distribution function to the front and rear wheels in the middle of the drive system for the front and rear wheels, and various output elements from this center differential device are provided. In a configuration in which a plurality of friction engagement elements having the function of are mounted, one friction engagement element arranges the hydraulic chamber and the piston on the fixed side and constantly connects the piston to one of the bearing and the front and rear wheels. A drive gear and drive plate are press-fitted into the ram member so that the drive gear and drive plate can be pressed.A pulse gear is formed on the outer periphery of the press member, and the electromagnetic pickup on the case side is placed facing this pulse gear. It is what is done.

[0007]

[Action]

 Based on the above configuration, in one friction engagement element attached to the center differential device, centrifugal hydraulic pressure is prevented from being generated in the fixed-side hydraulic chamber and the piston, and, for example, the torque distribution of the front and rear wheels is accurately and variably controlled. It Further, by detecting the pulse gear of the pressing member that is always connected to one of the front and rear wheels with this friction engagement element by the electromagnetic pickup, the vehicle speed can be detected well.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, as a four-wheel drive vehicle with a center differential device to which the present invention is applied, a drive system of a first embodiment in which an engine and an automatic transmission are vertically arranged in the vehicle longitudinal direction will be described. First, the transmission case 3 is joined to the rear part of the torque converter case 1 and the differential case 2, the transfer case 4 and the extension case 6 are joined to the rear part of the transmission case 3, and the oil pan 5 is attached to the lower part of the transmission case 3. Mounted.

Reference numeral 10 is an engine. A crankshaft 11 of the engine 10 is connected to a torque converter 13 having a lockup clutch 12 inside the torque converter case 1, and an input shaft 14 from the torque converter 13 is connected to a transmission case 3. Input to the internal automatic transmission 30. A transmission output shaft 15 from the automatic transmission 30 outputs coaxially with the input shaft 14, and the transmission output shaft 15 is coaxially connected to a center differential device 50 inside the transfer case 4.

Inside the transmission case 3, a front drive shaft 16 is arranged in parallel to the input and output shafts 14 and 15. The rear end of the front drive shaft 16 is attached to the center differential device 50 by a pair of reduction gears 17, The front end of the front drive shaft 16 is connected to the front wheels via a front differential device 19 inside the differential case 2. On the other hand, a hydraulic multi-disc clutch device 60 is provided at the rear of the center differential device 50, and the rear drive shaft 20 that outputs from the hydraulic multi-disc clutch device 60 passes through a propeller shaft 21, a rear differential device 22, and the like. It is configured to be transmitted to the rear wheels.

The automatic transmission 30 is configured to obtain four forward gears and one reverse gear by two sets of front planetary gears 31 and rear planetary gears 32. That is, the input shaft 14 is connected to the sun gear 32a of the rear planetary gear 32, the ring gear 31b of the front planetary gear 31 and the carrier 32c of the rear planetary gear 32 are connected to the transmission output shaft 15. A first one-way clutch 34 and a forward clutch 35 are provided in series between the ring gear 32b and a connecting element 33 that is integral with the carrier 31c of the front planetary gear 31, and is a case that is a connecting member 33 and a fixing member. A second one-way clutch 36 and a low reverse brake 37 are provided in parallel with the side. An overrunning clutch 38 is provided as a bypass between the connecting element 33 and the ring gear 32b.

A band brake 40 is provided on the connecting element 39 integrated with the sun gear 31 a, and is provided between the connecting element 41 integrated with the input shaft 14 and the connecting element 42 integral with the carrier 31 c. Is provided with a high clutch 43. Further, a reverse clutch 44 is provided between the connecting elements 39 and 41.

Due to the structure of the automatic transmission 30, the forward clutch 35 is engaged in the first speed of the D range or the third range and the second range, and in the case of acceleration, the one-way clutches 34 and 36 work together with the coupling element 33 and the ring gear. By locking 32b, power is transmitted from the input shaft 14 to the transmission output shaft 15 via the sun gear 32a and the carrier 32c. At this time, the first one-way clutch 34 becomes free during coasting, and even if the free running of the first one-way clutch 34 is restricted by engaging the over-running clutch 38, the second one-way clutch 36 remains. It becomes free and the engine brake does not work. At the 1st speed in the 1st range, the engine brake operates because the low reverse clutch 37 is always engaged to lock the ring gear 32b via the overrunning clutch 38.

At the second speed of the D range or the third range and the second range, the forward clutch 35 and the band brake 40 are engaged, and the band gear 40 locks the sun gear 31 a. Then, the carrier 31c and the ring gear 32b rotate via the coupling element 33, the forward clutch 35, and the first one-way clutch 34, and the power increased by the amount of rotation of the ring gear 32b is output as compared with the case of the first speed. At this time, at the time of deceleration, the reverse driving force is transmitted to the engine side and the engine brake acts by keeping the connecting element 33 and the ring gear 32b connected by the engagement of the overrunning clutch 38.

In the third speed of the D range or the third range, the forward clutch 35 and the high clutch 43 are engaged, and the high clutch 43 causes the input shaft 14 to engage the connecting elements 41 and 42, the carrier 31c, the connecting element 33, and the forward clutch. 35, and is connected to the ring gear 32b via the first one-way clutch 34. Therefore, the rear planetary gear 32 is integrated and the input shaft 14 and the transmission output shaft 15 are directly connected. At this time, when decelerating, the overrunning clutch 38 is coupled to restrict the idling of the first one-way clutch 34, so that the engine brake acts similarly to the second speed.

In the 4th speed of the D range, the sun gear 31a is locked by the engagement of the band brake 40 in addition to the above. Therefore, the power input to the carrier 31c by the high clutch 43 in the front planetary gear 31 accelerates the ring gear 31b, which is transmitted to the transmission output shaft 15. In this case, the engine brake always acts because the first and second one-way clutches 34 and 36 are not used.

In the R range, the power of the input shaft 14 is input to the sun gear 31a by coupling the reverse clutch 44. Further, since the carrier 31c is locked together with the coupling element 33 by the engagement of the low reverse clutch 37, the front planetary gear 31 reversely rotates to the ring gear 31b to output power with a large gear ratio, and this reverse power is transmitted to the transmission output shaft 15. To the reverse speed. In this way, the automatic transmission 30 can obtain a shift speed of four forward gears and one reverse gear.

On the other hand, an oil pump 45 is installed in front of the automatic transmission 30 and is constantly driven by a drive shaft 46 on the pump impeller side of the torque converter 13. A control valve body 47 is housed in the oil pan 5 so that oil can be supplied to and discharged from each of the above-mentioned clutches and brakes and selectively engaged.

In FIG. 2, parts of the center differential device 50 and the hydraulic multi-plate clutch device 60 will be described. First, the rear drive shaft 20 is coaxially arranged behind the transmission output shaft 15 via the first and second intermediate shafts 23 and 24. Further, the reduction gear 17 on the front wheel side is rotatably fitted to the transmission output shaft 15, and between the transmission output shaft 15, the reduction gear 17 and the first and second intermediate shafts 23, 24, The center differential device 50 is arranged coaxially.

The center differential device 50 is configured as a compound planetary gear, and includes a first sun gear 51 formed on the transmission output shaft 15 and a second sun gear 53 formed on the second intermediate shaft 24. Have. Further, the carrier 55 is formed by integrally combining the left and right flanges 55a and 55b with an arm 55c, and the pinion shaft 56 mounted between the flanges 55a and 55b is integrally formed in the first and second axial directions. The pinions 52 and 54 are rotatably mounted via the needle bearing 27. The first sun gear 51 is meshed with the first pinion 52, and the second sun gear 53 is meshed with the second pinion 54. The torque-distributed power is output to the second intermediate shaft 24.

On the other hand, the first intermediate shaft 23 is further loosely fitted inside the second intermediate shaft 24, and a connecting member is provided at the front end of the first intermediate shaft 23 at a gap between the two sun gears 51 and 53. 57 is coupled, and the connecting member 57 is integrally spline-coupled to the arm 55c of the carrier 55 to perform a function such as differential limiting. Further, the reduction gear 17 is coupled to one flange 55a of the carrier 55 so as to output the power of the carrier 55. Here, in front of the carrier 55, the reduction gear 17 integrated with the carrier 55 is supported by the ball bearing 26a with respect to the transmission case 3, and at the rear, the outer periphery of the boss portion 55d of the flange 55b is supported by the ball bearing 26b with respect to the transfer case 4. It is supported, and its inner circumference is supported by the ball bearing 26c against the second intermediate shaft 24, and is rotatably installed with both ends supported.

With the configuration of the center differential device 50, the power input to the first sun gear 51 is supplied to the gear specifications of the first and second sun gears 51 and 53 and the first and second pinions 52 and 54. Has a function of transmitting the torque to the carrier 55 and the second sun gear 53 at a torque distribution ratio of 1 to distribute the unequal torque to the front and rear wheels. Further, the planetary rotation of the first and second pinions 52 and 54 has a differential function of absorbing a rotational speed difference between the carrier 55 and the second sun gear 53 caused by a difference in turning radius at the time of turning.

The unequal torque distribution function of the center differential device 50 will be described in detail with reference to the schematic diagram of FIG. The input torque of the first sun gear 51 is Ti, the meshing pitch radius thereof is rs1, the front side torque of the carrier 55 is TF, the meshing pitch radii of the first and second pinions 52 and 54 are rp1 and rp2, and the second Let TR be the rear torque of the sun gear 53 and rs2 be its meshing pitch radius, then Ti = TF + TR (1) rs1 + rp1 = rs2 + rp2 (2) holds.

Further, the tangential load P acting on the meshing point between the first sun gear 51 and the first pinion 52 is the tangential load P1 acting on the carrier 55, the second sun gear 53 and the second sun gear 53. Since it is equal to the sum of the tangential load P2 acting on the meshing point with the pinion 54, the following equation holds. P = Ti / rs1 P1 = TF / (rs1 + rp1) P2 = TR / rs2 Ti / rs1 = {(TF / (rs1 + rp1)} + TR / rs2 (3) Then, the equations (1) and (2) are changed to (3). Substituting into the formula and rearranging it is as follows: TF = (1−rp1 · rs2 / rs1 · rp2) × Ti TR = (rp1 · rs2 / rs1 · rp2) × Ti

From this, the reference pitches of the front torque TF and the rear torque TR are determined by the meshing pitch radii of the first and second sun gears 51 and 53 and the first and second pinions 52 and 54. It can be seen that the torque distribution ratio can be set freely. Here, rs1, rp1, rp2, and rs2 can be replaced with the numbers of teeth Zs1, Zp1, Zp2, and Zs2, respectively. If Zp1 = Zp2 = 21, Zs1 = 33, and Zs2 = 21, then TF: TR = 36.4. : 63.6. Therefore, it is possible to sufficiently set the reference torque distribution ratio of the rear wheel deviation.

Next, a case where the center differential device 50 is used as a speed increasing device will be described. In this composite planetary gear type center differential device 50, a predetermined speed increasing gear ratio can be obtained by fixing the second intermediate shaft 24. This speed increasing gear ratio is independent or a predetermined speed change step of the automatic transmission 30. The gear shifts to the 5th speed by the action of the. Therefore, for example, the case of using the second speed gear stage will be described. The gear ratio i5 of the fifth speed is as follows due to the gear ratio i2 of the second speed and the speed increasing gear ratio ip of the center differential device 50. .. i5 = i2 · ip Here, if the above-mentioned gear specifications are used for the center differential device 50, then ip = (33-21) /33=0.363, and, for example, i2 = 1.545, i5 = 0.561, which means that the fifth speed, which has a smaller gear ratio than the fourth speed, can be obtained at an appropriate gear ratio interval. On the other hand, in the fifth speed, a transmission torque is generated by controlling the hydraulic pressure of the hydraulic multi-plate clutch 62 according to the traveling state and the road surface condition, and the four-wheel drive becomes possible in which the torque distribution of the front and rear wheels can be controlled.

Referring to FIG. 3, the hydraulic multi-plate clutch device 60 will be described. First, a hydraulic multi-plate clutch 61 as a friction engagement element for transmitting torque, which is interposed between the second intermediate shaft 24 and the rear drive shaft 20, the first intermediate shaft 23, and the rear drive shaft. 20 and a hydraulic multi-plate clutch 62 as a frictional engagement element for differential limiting and torque movement, and a second intermediate shaft 24, which blocks the differential function of the center differential device 50. And a fifth speed brake 63 as a friction engagement element for increasing the speed of rotation of the carrier 55. Immediately after the center differential device 50, the hydraulic multi-plate clutches 61 and 62 and the fifth speed brake 63 are overlapped with each other in the radial direction around the first intermediate shaft 23, etc., and are arranged coaxially. To be done. That is, the hydraulic multi-plate clutches 61 and 62 are both connected to the rear drive shaft 20, and the hydraulic multi-plate clutch 61 and the fifth speed brake 63 are both connected to the second intermediate shaft 24. The plate clutch 61 is arranged in the middle, the fifth speed brake 63 is arranged outside the hydraulic multi-plate clutch 61, and the hydraulic multi-plate clutch 62 is arranged inside.

Therefore, the drum member 64 is spline-coupled to the second intermediate shaft 24, and the drum member 65 integrally formed at the front end of the rear drive shaft 20 is arranged inside the drum member 64. A hydraulic multi-plate clutch 61 is provided between 64 and 65. In the hydraulic multi-plate clutch 61, drive plates 61a and driven plates 61b are alternately provided between drum members 64 and 65, and a hydraulic chamber 61c, a piston 61d, and a return spring 61e are provided inside the drum member 64. It is configured to connect or disconnect the middle shaft 24 to the rear drive shaft 20.

The fifth speed brake 63 is provided with a drive plate 63 a and a driven plate 63 b alternately between the drum member 64 and the transfer case 4, and a hydraulic chamber 63 c, a hydraulic chamber 63 c, inside the wall portion 4 a of the transfer case 4. A piston 63d and a return spring 63e are provided and are configured to fix or free the second intermediate shaft 24.

In the hydraulic multi-plate clutch 62, a drive plate 62 a and a driven plate 62 b are alternately provided between the hub member 66 and the drum member 65 that are splined to the first intermediate shaft 23. A hydraulic chamber 62c, a piston 62d, and a return spring 62e are provided inside the boss portion 6a of the extension case 6 on the fixed side to generate a large pressing force and accurately control the hydraulic pressure without being affected by the centrifugal hydraulic pressure. Can be provided. The piston 62d is connected to the plate side via a ball bearing 62f and a pressing member 62g, and is configured to generate a differentially limited torque and a transmission torque that are variably controlled. A bush 28 is provided in the shaft fitting portion, and a thrust bearing 25 is provided in the abutting portion between the shafts and the shaft and other members.

Further, in the hydraulic multi-plate clutch 62, a pressing member 62g for inserting the rod portion 62h is provided inside the drum portion member 65 integrated with the rear drive shaft 20. The pressing member 62g is always rotating in correspondence with the wheel speed of the rear wheels. Therefore, a pulse gear 71 of the vehicle speed sensor 70 is formed on the outer periphery of the pressing member 62g, and an electromagnetic pickup 72 is attached to the extension case 6 so as to closely face the pulse gear 71. As a result, by detecting the pulse gear 71 of the pressing member 62g with the electromagnetic pickup 72, the vehicle speed while the vehicle is stopped and running can always be detected well.

The hydraulic multi-plate clutches 61 and 62 and the fifth speed brake 63 are hydraulically controlled by the control valve body 47 together with the shift control of the automatic transmission 30 and the like. Immediately, when the automatic transmission 30 shifts to four forward speeds and one reverse speed, the fifth speed brake 63 is released and the hydraulic multi-plate clutch 61 is engaged. A differential limiting torque is generated in the hydraulic multi-plate clutch 62. When the vehicle speed increases above the set value at the 4th speed, on the contrary, the fifth speed brake 63 is engaged to release the hydraulic multi-plate clutch 61, and at this time, the hydraulic multi-plate clutch 62 is disengaged in response to front wheel slip or the like. Produces transmission torque.

As shown above, Table 1 shows a summary of the clutch and brake operations of the automatic transmission 30 and the center differential device 50 at each shift stage of the D range and the R range.

[Table 1] In Table 1, the circle marks indicate the engagement operation of the clutches and brakes, the black circles indicate the generation of differential limiting torque by the hydraulic multi-plate clutch 62, and the double circles indicate the distribution of the driving force to the front and rear wheels by the hydraulic multi-plate clutch 62. The transmission torque states for control are shown respectively.

Further, Table 2 shows a gear ratio, an example of the gear ratio, and a torque distribution ratio in each shift stage.

[Fig. 2] In Table 2, α1 is the ratio of the number of teeth Zs1 of the sun gear 31a of the front planetary gear 31 and the number of teeth Zr1 of the ring gear 31b, α1 = Zs1 / Zr1, and α2 is the number of teeth Zs2 of the sun gear 32a of the rear planetary gear 32 and the ring gear 32b. The ratio of the number of teeth Zr2 indicates α2 = Zs2 / Zr2.

The relationship between the rotational speeds of the respective elements of the front planetary gear 31 is shown by the following equation. Nr1 + α1 · Ns1 = (1 + α1) · Nc1 However, α1 = Zs1 / Zr1 The relationship between the rotational speeds of the respective elements of the rear planetary gear 32 is as follows. Nr2 + α2 · Ns2 = (1 + α2) · Nc2 where α2 = Zs2 / Zr2 where the rotational speed Nr1 of the ring gear 31b of the front planetary gear 31, the rotational speed Ns1 of the sun gear 31a, the rotational speed Nc1 of the carrier 31c, and the rear planetary gears are used. The rotation speed Nr2 of the ring gear 32b of 32, the rotation speed Ns2 of the sun gear 32a, and the rotation speed Nc2 of the carrier 32c.

Next, the operation of this embodiment will be described. First, the power of the engine 10 is input to the automatic transmission 30 via the torque converter 13 and the input shaft 14, the operation of the two front planetary gears 31 and the rear planetary gears 32, and the clutches 44, 43, 35, 38, 36. , 34 and the brakes 40, 37 are selectively engaged to shift to the D range, the forward speed is automatically changed to the first to fourth speeds, and when shifting to the R range, the reverse speed is set. Then, this shift power is input from the transmission output shaft 15 to the first sun gear 51 of the center differential device 50, and torque is distributed. Further, in this case, the hydraulic multi-plate clutch 61 of the hydraulic multi-plate clutch device 60 is engaged, and the second sun gear 53 of the center differential device 50 is connected to the rear drive shaft 20.

Here, since, for example, T F: TR = 36.4: 63.6 is set by each gear specification of the center differential device 50, 36.4% of the shift power is 63 in the carrier 55 and 63 in the carrier 55. 0.6% is distributed to the second sun gear 53 and output. Then, the power of the carrier 55 is transmitted to the front wheels through the reduction drive gear 17, the reduction driven gear 18, the front drive shaft 16, and the front differential device 19. Further, the power of the second sun gear 53 is transmitted to the second intermediate shaft 24, the hydraulic multi-plate clutch 61, and the rear wheels after the rear drive shaft 20, and the four-wheel drive running with the rear wheel being deviated, resulting in this torque. In distribution, oversteering tends to occur, and turning and maneuverability are improved. During this four-wheel drive traveling, the planetary rotation of the first and second pinions 52 and 54 of the center differential device 50 absorbs the difference in the rotational speeds of the front and rear wheels generated during the rotation, and the vehicle can freely turn. ..

Next, when the vehicle travels on slippery roads, the reference torque distribution is a torque distribution with a rear wheel bias, so the rear wheels usually slip first, and in this case, the differential limiting torque Tc of the hydraulic multi-plate clutch 62 is in a slip state. Controlled according to. Then, between the carrier 55 of the center differential device 50 and the second sun gear 53, the carrier 55, the connecting member 57, the first intermediate shaft 23, and the other transmission system path by the hydraulic multi-plate clutch 62 are bypassed. The second sun gear 53 having a high rotation speed is bypassed from the rear wheel side to the front wheel side of the low rotation carrier 55 according to the differential limiting torque Tc. There, torque distribution is controlled toward the front wheels to prevent rear wheel slip and improve running performance.

At this time, when the differential limiting torque Tc becomes the maximum, the center differential device 50 is locked by the direct connection between the second sun gear 53 and the carrier 55 to become the direct-connection type four-wheel drive, and the load distribution of the front and rear wheels is distributed. The torque distribution is equivalent. By controlling the differential limiting torque Tc in this way, the torque distribution is variably controlled between the rear wheel bias and the direct coupling type.

On the other hand, when the speed becomes higher than the traveling condition of the fourth speed, the automatic transmission 30 becomes the second speed state and, at the same time, the second differential of the center differential device 50 is engaged by the engagement of the fifth speed brake 63. The sun gear 53 is fixed and the carrier 55 is rotated at an increased speed. Therefore, the power of the second speed of the automatic transmission 30 is significantly increased by the center differential device 50 and is transmitted to the front wheels of the carrier 55 and thereafter, and the power of the overdrive having a smaller gear ratio than that of the fourth speed is used. It becomes possible to travel at high speed by shifting to the 5th speed. In this case, understeer tends to occur and high-speed stability is improved. At this time, when the transmission torque T D of the hydraulic multi-plate clutch 62 is variably controlled according to the running state, the situation of front wheel slip, etc., the rear torque is transferred from the carrier 55 via the first intermediate shaft 23 and the hydraulic multi-plate clutch 62. Torque is also transmitted to the wheels. Therefore, the front wheel slip is prevented, and at the same time, the four-wheel drive traveling in which the torque distribution of the front and rear wheels is similarly controllable.

Although the embodiment of the present invention has been described above, the vehicle speed sensor can be similarly applied to a friction engagement element having a function other than the torque distribution control.

[0042]

[Effect of the device]

 As described above, according to the present invention, in a four-wheel drive vehicle with a center differential device, when the center differential device is configured to have multiple functions and includes a plurality of hydraulic multi-plate clutches, brakes, etc., Since the vehicle speed sensor is configured by using one hydraulic multi-plate clutch component to form the pulse gear, the number of parts is reduced, the structure is simplified, and the cost is reduced. In the hydraulic multi-plate clutch, since the pulse gear is formed on the pressing member mounted on the drum member, the degree of freedom in setting the number of gear teeth and height is increased, and the vehicle speed detection condition can be optimally formed. , It is not affected by the arrangement structure on the drum side.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing an overall embodiment of a vertically arranged four-wheel drive vehicle with a center differential device according to the present invention.

FIG. 2 is an enlarged cross-sectional view of portions of a center differential device and a hydraulic multiple disc clutch device.

FIG. 3 is an enlarged sectional view of a hydraulic multi-plate clutch device and a vehicle speed sensor.

FIG. 4 is a schematic diagram for explaining a torque distribution state, a differential limitation, and a flow of transmission torque for direct coupling.

[Explanation of symbols]

 15 Transmission output shaft 16 Front drive shaft 17,18 Reduction gear 20 Rear drive shaft 30 Automatic transmission 50 Center differential device 60 Hydraulic multi-plate clutch device 61,62 Hydraulic multi-plate clutch (friction engagement element) 63 For fifth speed Brake (friction engagement element) 62a Drive plate 62b Driven plate 62c Hydraulic chamber 62d Piston 62f Ball bearing 68 Pressing member 65 Drum member 70 Vehicle speed sensor 71 Pulse gear 72 Electromagnetic pickup

Claims (1)

[Scope of utility model registration request] 1. A center differential device having a torque distribution function to the front and rear wheels is arranged in the middle of a drive system for the front and rear wheels, and a plurality of friction elements having various functions are provided to an output element from the center differential device. In the configuration in which the engagement elements are mounted, one friction engagement element is
The hydraulic chamber and piston are arranged on the fixed side, and this piston is configured to be pressably connected to the drive and driven plate via a pressing member that is inserted into a drum member that is always connected to one of the bearing and front and rear wheels. A four-wheel drive vehicle with a center differential device, characterized in that a pulse gear is formed on the outer periphery of the member, and a case-side electromagnetic pickup is disposed so as to face the pulse gear.