JPH0129137Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a slip control device for a tandem axle vehicle that is mainly installed on a large vehicle.

[Prior Art] A normal tandem axle is equipped with an intermediate differential device, which releases the rotational difference caused by the difference in trajectory between the rear front wheels and the rear wheels when the vehicle is turning, and prevents so-called axle fights. If the wheels slip on muddy ground, the front and rear wheels lose driving force, making it impossible to drive.

In order to prevent such problems, a deflock mechanism in which the differential function of an intermediate differential gear can be locked at any time is known, for example, in US Pat. No. 3,388,760. However, in the conventional intermediate differential gear equipped with a differential lock mechanism, the vehicle must be stopped each time the differential lock mechanism is activated or released. Furthermore, if the vehicle is driven without disengaging the deflock mechanism, there is a problem in that steering stability is impaired and abnormal tire wear occurs.

[Problems to be solved by the invention] The purpose of the invention is to provide a slip prevention device for tandem axle vehicles in which a deflock mechanism automatically operates when slip occurs between the rear front wheels and the rear wheels. It's about doing.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the present invention includes a carrier that supports an input bevel gear that meshes between a pair of output bevel gears of an intermediate differential, and one output bevel gear. A hydraulic clutch is provided between the gears, and an electromagnetic control valve is connected between the hydraulic pump and the hydraulic clutch, which are interlocked and connected to the carrier. The switching is performed by a control device based on

[Function] Rotation speed sensors 65, 64 that detect the rotation speed of the output bevel gears 28, 30 are provided opposite to the output shafts 32, 47, and when the difference in the rotation speeds between the two exceeds a predetermined value, the hydraulic clutch 70 is activated. The input shaft 29 and the output bevel gear 28 are rotationally coupled. Therefore, the intermediate differential device A is locked, the slip between the rear front wheels and the rear rear wheels is eliminated, and it becomes possible to escape from the muddy area.

[Example of the invention] The invention will be explained based on an example. As shown in FIG. 1, the intermediate portion of the axle case 42 of the final reduction gear B that supports the rear and front shafts 36 has a substantially rectangular cross section, and has openings in the front and rear walls. A known differential device for obtaining a rotational differential between the left and right wheels of the rear and front shaft 36 is housed in the rear and front shafts 36. The rear wall portion of the axle case 42 is closed with a cover. Furthermore, the cases 22, 25, and 60, which are made up of three parts, are coupled to the front wall of the axle housing 42.

The input shaft 2 is connected to the front end of the case 60 by a bearing 12.
9 is supported, and a propulsion shaft (not shown) is connected to the input shaft 29 via a universal joint 11 connected by a spline. The right end of the input shaft 29 is hollow, and a carrier 46 of the intermediate differential A is coupled to this. That is, a shaft 13 perpendicular to the input shaft 29 is supported inside a box-shaped carrier 46 formed by combining the divided bodies, and an input bevel gear 27 is supported on the shaft 13. An input bevel gear 27 and a pair of output bevel gears 2
8 and 30 are engaged. The output bevel gear 30 is coupled to a hollow first output shaft 47 by a spline. The output bevel gear 28 is connected to the second output shaft 32 inserted through the first output shaft 47 by a spline. In this way, the rotational force of the input shaft 29 is transmitted to the first output shaft 47 for driving the rear and front shafts 36 and the second output shaft 32 for driving the rear and rear shafts. There is.

A hollow first output shaft 47 is rotatably supported by a pair of bearings 14 and 40 with respect to the case 25, and a gear 15 is integrally formed in the intermediate portion thereof. Gear 15 is meshed with gear 23. gear 2
3 is rotatably connected to an input shaft 39 of a rear-front final reduction gear B supported by a bearing 38 on the intermediate wall of the case 25. A crown gear 41 is meshed with a drive bevel gear 37 that is integrally formed on the right end of the input shaft 39 . The crown gear 41 transmits rotation to the input side of a known differential, and ultimately drives the left and right rear and front shafts 36. The differential device is well known and is not directly related to the present invention, so a description thereof will be omitted.

A gear 16 is formed at the right end of the first output shaft 47 . On the other hand, the left end of the second output shaft 32 is rotatably fitted and supported by the bevel gear 30, and the second output shaft 32 is rotatably fitted and supported by the bevel gear 30.
A gear 17 is formed in a portion protruding from the gear 7, and its right end portion is supported by the cover of the axle case 42 by a bearing 49, and is connected to a final reduction gear B of the rear axle (not shown) by a universal joint. That is, the relay shafts are connected via the universal joint, and the relay shafts are connected to the input shafts of the final reduction gears of the rear and rear shafts, similarly to the input shafts 39 of the final reduction gears B of the rear and front shafts 36.

An important feature of the present invention is that a hydraulic clutch 70 is provided between the end of the input shaft 29 and the output bevel gear 28 of the intermediate differential A to lock the differential function. A hydraulic pump 50 is provided on the end wall of the case 60 to drive the hydraulic actuator 76 . The hydraulic pump 50 has a gear 54 supported on a shaft 53 and a gear 57 supported on a shaft 56 housed in a housing 55 fixed to a case 60 with bolts 58 in a meshed state, and has a suction port connected to a passage 59. , 61 and a filter 69 into the lubricating oil filled in the bottom of the case 22. Further, a discharge port of the hydraulic pump 50 is connected to an electromagnetic control valve 67 via passages 62 and 63, and further connected to an operating chamber of a hydraulic actuator 76. A shaft 53 of the hydraulic pump 50 is projected into the case 60 and is coupled to a gear 52. A gear 52 is meshed with a gear 51 fixed to the end of the carrier 46.

Control device 66 for controlling the electromagnetic control valve 67
is operated based on the rotational speed of the first output shaft 47 and the second output shaft 32. For this reason, an electromagnetic pickup type rotation speed sensor 64 is arranged opposite to the gear 16 formed on the first output shaft 47 to detect the rotation speed. Further, a rotation speed sensor 65 is arranged opposite to the gear 17 provided on the second output shaft 32 .

As shown in FIG. 2, in the hydraulic clutch 70, the end of the input shaft 29 is rotatably fitted inside the case 60, and the flange 29a is connected to the bolt 7.
1 to the carrier 46. Input shaft 29
A spline 81 is formed in the inner cavity of the end, and a plurality of friction plates 80 are slidably fitted and supported on the spline 81. On the other hand, a spline 79 is formed on the boss portion of the output bevel gear 28, and a friction plate 78 is slidably fitted and supported on the spline 79, and is disposed between the friction plates 80.

A hydraulic actuator 76 is configured at the end of the carrier 46 to frictionally engage the friction plates 80, 78 with each other. A cylinder 75 is provided on the carrier 46, and a piston 77 is fitted into the cylinder 75.
is brought into contact with the friction plate 80. The cylinder 75 includes a passage 74, an annular cavity 73 between the flange 29a and the carrier 46, a passage 72 for the input shaft 29, and an annular groove 7.
2a, the electromagnetic control valve 6 via the passage 63 of the case 60
Connected to 7.

Next, the operation of the device of the present invention will be explained. Gear 16 detected by rotation speed sensors 64 and 65
When the rotation difference between the gear 17 and the gear 17 exceeds a predetermined value s (FIG. 3), the output signal of the control device 66 is activated by the electromagnetic control valve 6.
7, and pressure oil is supplied from the hydraulic pump 50 to the hydraulic actuator 76. The hydraulic pressure applied to the hydraulic actuator 76 increases in proportion to the rotational difference, as shown in FIG. Therefore, when a rotation difference occurs between the rear front wheels and the rear wheels due to slipping when driving on a rough road, hydraulic pressure proportional to the rotation difference is applied to the hydraulic actuator 76 of the hydraulic clutch 70, and the input shaft 29 Slippage between the second output shaft 32 and the second output shaft 32 is restricted, and driving force is transmitted to the rear front wheels and the rear rear wheels.

As mentioned above, in this invention, a hydraulic clutch is attached to the intermediate differential and is activated in response to the difference in rotation between the rear front wheels and the rear wheels, so that the wheels can be easily moved on muddy or icy roads. If the vehicle slips and a difference in rotation occurs between the front and rear wheels, this condition is detected electrically and the hydraulic clutch is automatically engaged. Therefore, the differential function of the intermediate differential device is locked, the rear front wheels and the rear rear wheels are driven integrally, and a situation where the vehicle cannot run is avoided.

When normal driving conditions return, that is, when the rotational difference between the rear front wheels and the rear wheels disappears, the hydraulic clutch is automatically disconnected, and the differential function of the intermediate differential is restored, ensuring smooth driving. and steering stability is maintained.

Since the intermediate differential is automatically locked and released, abnormal tire wear caused by forgetting to release the lock, which is the case with conventional deflock mechanisms, is eliminated.

[Effects of the invention] As described above, the present invention provides a hydraulic clutch between one of the output bevel gears and the carrier that supports the input bevel gear that meshes between the pair of output bevel gears of the intermediate differential. , because the electromagnetic control valve connected between the hydraulic pump and the hydraulic clutch, which are interlocked and connected to the carrier, is switched by a control device based on a signal from a rotation speed sensor installed opposite to the shaft of a pair of output bevel gears. When the difference in the rotational speed between the first and second output bevel gears in the intermediate differential exceeds a predetermined value, the hydraulic clutch is automatically connected and the intermediate differential is locked. It becomes easier to escape from.

When the rotational speeds of the first and second output bevel gears almost match, the hydraulic clutch is disconnected and the function of the intermediate differential gear is restored, allowing differential rotation between the rear front wheels and the rear wheels. Abnormal tire wear is avoided.

In this invention, it is only necessary to install a hydraulic clutch in the intermediate differential, and the hydraulic pump can be installed on the outer wall of the case without changing the conventional tandem axle, so the mechanical components are reduced. It is simple and can be provided at low cost.

According to the present invention, since the hydraulic pump is interlocked and connected to the carrier of the intermediate differential, if the pressure release part of the electromagnetic control valve is placed adjacent to the hydraulic clutch, the differential can be lubricated. is improved.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a tandem axle equipped with an anti-slip device according to the present invention, Fig. 2 is an enlarged side sectional view showing the main parts of the anti-slip device, and Fig. 3 is a sectional view of the tandem axle equipped with an anti-slip device according to the present invention. FIG. 3 is a diagram showing operating characteristics. 16, 17: Gear, 28, 30: Output bevel gear,
29: Input shaft, 32: Second output shaft, 42: Axle case, 46: Carrier, 47: First output shaft, 50: Hydraulic pump, 51, 52: Gear, 6
4, 65: Rotation speed sensor, 66: Control device, 6
7: Solenoid control valve, 70: Hydraulic clutch.

Claims (1)

[Scope of utility model registration request] A hydraulic clutch is provided between a carrier that supports an input bevel gear that meshes between a pair of output bevel gears of the intermediate differential and one of the output bevel gears, and a hydraulic pump and a hydraulic clutch are interlocked and connected to the carrier. A slip prevention device for a tandem axle vehicle in which an electromagnetic control valve connected between the two is switched by a control device based on a signal from a rotation speed sensor installed opposite to the shaft of a pair of output bevel gears.