JPH0723298Y2 - Construction vehicle axle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an axle for a four-wheel drive construction vehicle equipped with a disconnect device.

[Prior Art] Generally, a construction vehicle is a four-wheel drive when performing main work such as excavation and loading, but when traveling at a high speed on a flat hard soil road surface, the construction of a power system is different due to a difference in effective radius of tires. In order not to overdo it, power is transmitted to only one of the front wheels or the rear wheels and the vehicle is driven by two-wheel drive. Thus, a disconnect device is provided at one end of the output shaft of the transmission as a switching means from the four-wheel drive to the two-wheel drive.

[Problems to be solved by the invention]

However, in the conventional construction vehicle, even if either the front wheel or the rear wheel cuts off the power transmission by the disconnect device during two-wheel drive, the power system such as the propulsion shaft and the differential gear device is driven by running. Since the wheel spins as the wheel rotates, there is a problem that power loss, vibration, and noise are likely to occur due to inertial weight and frictional resistance.

The present invention solves such a problem in a conventional construction vehicle, and an object of the present invention is to provide an axle device that prevents power loss, vibration, and noise by eliminating idling of a power system during two-wheel drive traveling. .

[Means for solving problems]

In order to solve the above problems, an axle of a construction vehicle of the present invention includes a planetary gear reduction device, a friction plate fitted to a spline provided on the outer periphery of an internal gear of the planetary gear reduction device, an axle housing, and A clutch plate fitted to a spline provided inside the integrally formed clutch housing, a piston that constantly presses the clutch plate and the friction plate in the engaging direction, and a piston that operates in the anti-engaging direction. An oil chamber and an operation pipe line connected to the oil chamber via a switching valve are provided.

[Action]

During low-speed four-wheel drive, in which the construction vehicle performs the main work, the piston presses the clutch plate and the friction plate into engagement, and the internal gear of the planetary gear reducer is fixed integrally with the axle housing. Power is transmitted from the sun gear through the planetary gears to the output shaft to which the wheels are fastened. When a construction vehicle travels at high speed by two-wheel drive, transmission of power to one of the propulsion shafts is cut off by the disconnect device. At this time, the switching valve is switched to communicate the operation pipe line, and the piston is operated in the anti-engagement direction to release the engagement between the internal gear of the planetary gear speed reducer and the axle housing. Then, since the internal gear rotates freely, it is in a neutral state in which power is not transmitted between the sun gear and the planet gears. Therefore, on the non-driving side during two-wheel drive traveling, even if the wheels rotate, the propulsion shaft, the differential gear device, etc. do not idle, and power loss, vibration, and noise are prevented.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view of a power transmission system of a construction vehicle. The power of a prime mover 1 is transmitted to a transmission 3 via a torque converter 2 and is shifted by the transmission 3 to output from an output shaft 4 of the transmission. It is transmitted to the front and rear propulsion shafts 5 and 6, respectively. Rear propulsion shaft 6
Drive power to the rear wheels 10 via the rear first reduction gear 7, the rear differential gear 8, and the second rear reduction gear 9. The power of the front propulsion shaft 5 drives the front wheels 15 via the front second propulsion shaft 11, the front first reduction gear 12, the front differential gear 13, and the front second reduction gear 14.

A disconnect device 16 is provided on the front propulsion shaft 5 side of the output shaft 4 of the transmission, so that by disconnecting and continuing the power transmission to the front propulsion shaft 5, two-wheel drive and four-wheel drive can be achieved. Switch. Reference numeral 17 is a main brake, 18 is a parking brake, and 19 and 20 are front and rear axles.

FIG. 2 is an explanatory view of the configuration of the axle 19 of this invention. Here, the output shaft of the axle 19 to which the front wheel 15 is fastened
21 is supported by an axle housing 23 via a bearing 22. The front second speed reducer 14 is a planetary gear speed reducer including a sun gear 24, a planetary gear 25, and an internal gear 26,
The output shaft 21 is directly connected to the planet frame 27, and the power transmitted from the front differential gear 13 to the sun gear 24 is transmitted to the output shaft 21. Spline 28 provided on the outer periphery of internal gear 26
A friction plate 29 is fitted to the clutch plate 32, and a clutch plate 32 is fitted to a spline 31 provided inside a clutch housing 30 formed integrally with the accelerator housing 23. Inside the clutch housing 30, there is provided a piston 34 that presses the friction plate 29 and the clutch plate 32 in the engaging direction (left in the figure) by a spring 33 that is always mounted on the rear surface. Reference numeral 35 is an oil chamber for operating the piston 34 in the opposite engagement direction (right in the figure), and an operation pipe line 38 is connected to the oil chamber 35 from a hydraulic pump 36 via a switching valve 37.

The switching valve 37 is a 2-position solenoid switching valve, and is normally operated by
When the switching signal is sent to the solenoid 40, the operation pipe 38 is connected from the hydraulic pump 36 to the oil chamber 35. Further, in this embodiment, a sensor 41 for detecting the rotation speed of the output shaft 21, and a controller 42 for sending a switching signal to the switching valve 37 when the construction vehicle reaches a predetermined traveling speed in response to the rotation speed detection signal of the sensor 41. It has and. Reference numeral 43 is a prime mover that drives a hydraulic pump, and 44 is a relief valve of the working pipe line 38.

During low-speed four-wheel drive in which the construction vehicle performs the main work, the piston 34 presses and engages the clutch plate 32 and the friction plate 29, and the internal gear 26 is fixed to the clutch housing 30 integrated with the accelerator housing 23. Therefore, the power transmitted from the front differential 13 to the second front speed reducer 14 is transmitted from the sun gear 24 to the front wheels 15 via the planetary gear 25, the planetary frame 27, and the output shaft 21.

When the construction vehicle travels at high speed with two-wheel drive, the power transmission to the front propulsion shaft 5 side is cut off by the disconnect device 16. At this time, the controller based on the rotation speed detection signal of the sensor 41
42 outputs a switching signal to switch the switching valve 37, and the operating line 38
And the piston 34 is operated in the anti-engagement direction. Therefore, the engagement between the internal gear 26 and the clutch housing 30 is released, the internal gear 26 rotates freely, the sun gear 24 and the planetary gear 25 are in a neutral state, and even if the front wheel 15 rotates due to traveling, The power system from the propulsion shaft 5 to the second front speed reducer 14 does not idle.

In this embodiment, the sensor 41 detects the traveling speed,
Although the switching valve 37 is configured to be switched by the controller 42, it may be configured to be switched based on the switching signal to the two-wheel drive of the disconnect device 16 or may be manually operated by the operator. Good.

[Effect of device]

According to this invention, it is possible to prevent wasteful idling of the propulsion shaft and the differential gear unit during two-wheel drive, so that power loss is small,
Fuel consumption can be reduced, vibration and noise at high speeds can be prevented, driveline wear can be reduced, and durability can be improved.

[Brief description of drawings]

FIG. 1 is a power transmission system diagram of a construction vehicle, and FIG. 2 is a configuration explanatory view of an axle of an embodiment of the present invention. In the figure, 15 is a front wheel, 19 is an axle, 21 is an output shaft, 23 is an axle housing, 24 is a sun gear, 25 is a planet gear, 26 is an internal gear, 27 is a planet frame, 28 and 31 are splines, 29 is a Friction plate, 30 is a clutch housing, 32 is a clutch plate,
33 is a spring, 34 is a piston, 35 is an oil chamber, 36 is a hydraulic pump,
Reference numeral 37 is a switching valve, and 38 is an operation pipe line.

Claims (1)

[Scope of utility model registration request] 1. A planetary gear reducer, a friction plate fitted to a spline provided on the outer periphery of an internal gear of the planetary gear reducer, and a clutch housing formed integrally with an axle housing. A clutch plate fitted to the spline, a piston that constantly presses the clutch plate and the friction plate in an engaging direction, an oil chamber that operates the piston in an anti-engaging direction, and a switching valve in the oil chamber. An axle for a construction vehicle, comprising: an actuation line connected to the axle.