JPH069857Y2 - Driven wheel rotation sensor - Google Patents

Description

[Detailed description of the device]

[Industrial applications]

The present invention is equipped with a wet multi-plate transfer clutch.
The present invention relates to a driven wheel rotation sensor of a wheel drive vehicle (4WD vehicle), and more specifically, to a technique of controlling torque control of a transfer clutch based on output values of a vehicle speed sensor and a rear wheel rotation sensor.

[Prior art]

It has already been proposed that a 4WD vehicle has a transfer clutch composed of a wet multi-plate hydraulic clutch and that the clutch capacity is changed to carry out four-wheel drive for part time or full time. Here, in order to finely control the torque of the transfer clutch and apply it to various situations, it is necessary to detect the rotation difference between the front and rear wheels. Therefore, a rotation sensor is provided in each of the front and rear wheel drive systems, or one There is one that adds a rotation sensor to the driven wheel side using the signal of the speedometer. Conventionally, as for the above-mentioned rotation sensor, for example, JP-A-60-
Japanese Patent Laid-Open No. 201152 and Japanese Patent Laid-Open No. 60-151444 disclose that a gear train is used to attach a pickup thereto, or a rotating body is added to a drive system to attach the pickup thereto.

[Problems to be solved by the device]

By the way, in the case of using the gear of the above-mentioned prior art, it is difficult to make the gap between the gear and the pickup constant due to the difference in the gear outer diameter depending on the gear ratio, and the mounting flexibility of the pickup is also small. In addition, adding a rotating body to each of them causes an increase in cost, and there is a problem in that space is secured for that purpose. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a driven wheel rotation sensor that can be accurately detected by using a transfer clutch with a sufficient margin for mounting.

[Means for solving problems]

In order to achieve the above object, according to the present invention, when the transfer clutch drum is made of plastic-worked sheet metal, spline groove irregularities are formed at equal intervals on the outer circumference of the drum.
We pay attention to the fact that rotation can be detected by this convex portion. Therefore, in a configuration in which a transfer clutch is provided in the middle of the front and rear wheel drive system, and unevenness of the spline groove is formed on the outer periphery of the driven side drum of the transfer clutch, a vehicle speed detection sensor is provided in the power transmission system of the front wheels and A pickup is installed opposite to the driven side drum of the clutch, and a rotation sensor for detecting rotation is provided by the uneven portion of the driven side drum and the pickup, and an output signal of the vehicle speed detection sensor and an output value of the rotation sensor. Slip calculation means for calculating the slip ratio is provided, and the transmission torque of the transfer clutch is controlled by the output value of the calculation means.

[Action]

Based on the above configuration, the pickup detects the uneven portion of the drum that rotates with the driven wheel by the transfer clutch, and outputs a pulse signal according to the rotational speed of the driven wheel. Thus, in the present invention, by using a drum having a large diameter of the transfer clutch and being long in the axial direction, it is possible to improve the mounting flexibility, accuracy, etc. of the pickup.

【Example】

An embodiment of the present invention will be specifically described below with reference to the drawings. First, referring to FIG. 1, a transmission system of an example of a four-wheel drive vehicle to which the present invention is applied will be described. Reference numeral 1 is a crankshaft from an engine, and the crankshaft 1 is connected to a turbine shaft 3 via a torque converter 2. Connected, turbine shaft 3
Is configured to be transmitted to the automatic transmission 4. Automatic transmission 4
Are clutches 6, 7 for selectively inputting the power of the planetary gear 5, turbine shaft 3 to the input elements of the gear 5, and a one-way clutch 8, a brake 9, and a brake band 10 for selectively locking each element of the planetary gear 5. The output power from the automatic transmission 4 is taken out forward by the output shaft 11 and transmitted to the shaft 16 by the reduction drive gear 12 and the reduction driven gear 13. Further, a front wheel final reduction gear 14 is arranged below the torque converter 2 and the automatic transmission 4, and a crown gear 15 of the gear 14 has a drive pinion formed at one end of a shaft 16 integral with the gear 13. When 17 meshes, power is directly transmitted to the front wheels. The other side of the shaft 16 is extended rearward by a transfer drive shaft 18 and is mounted on the rear portion of the automatic transmission 4 to a transfer drive of a transfer device 19 and driven gears 20, 21.
Connect to. The gear 21 is connected to a rear drive shaft 23 via a transfer clutch 22 composed of a hydraulic clutch, and is configured to be transmitted from the rear drive shaft 23 to a rear wheel final reduction gear 25 via a propeller shaft 24. In this way, the power is further transmitted to the rear wheels in accordance with the torque capacity of the clutch 22, and the four-wheel drive traveling state is achieved. The transfer clutch 22 will be described in detail with reference to FIG. 2. The drive side driven gear 21 is integrally attached with the hub 30, the driven side rear drive shaft 33 is similarly attached with the drum 31, and the hub 30 and the drum 31 are spline-fitted. Plural plates 32 and 33 are alternately arranged, and the pistons 34 press the plates 32 and 33 to generate a predetermined torque capacity. Here, the drum 31 is made of sheet metal that has been plastically processed as shown in FIG. 3, and the concave portion 36 and the convex portion 37 of the spline groove 35 are formed.
Are formed on the outer periphery at equal intervals. So, pick up in the case 38 outside the drum 31
The drum 39 is sealed by an O-ring 40 and fixed with a bolt 41 so as to face each other.
The pickup 39 and the pickup 39 form a rear wheel rotation sensor 42. Next, the transfer clutch control system will be described. The signals of the front wheel rotation sensor 43 and the rear wheel rotation sensor 42 using the signals of the speedometer mounted on the front wheel side final reduction gear 14, for example, are input to the control circuit 44. To do.
The control circuit 44 outputs a duty signal according to the rotation difference between the front and rear wheels, and the control valve 45 is operated by this duty signal to change the hydraulic pressure of the transfer clutch 22. With the above configuration, the transfer clutch 22 can be used when the vehicle is traveling.
Drum 31 is always rotating with the rear wheels and its recess
36 and the convex portion 37 are detected by the pickup 39 of the rear wheel rotation sensor 42 and a pulse signal is output. Then, the rear wheel rotation speed is detected from the number of pulses per unit time. The signals from the rear wheel rotation sensor 42 and the front wheel rotation sensor 43 are input to the control circuit 44 to determine the rotation difference. For example, when the rotation difference is equal to or greater than full steering, the control valve 45 is operated by a 100% duty signal. Therefore, the hydraulic pressure of the transfer clutch 22 becomes maximum. Therefore, the torque capacity of the transfer clutch 22 is maximized, and the four-wheel drive mode in which the front and rear wheels are directly connected is achieved. Although one embodiment of the present invention has been described above, the present invention can be applied not only to the front engine / front drive base but also to the front engine / rear drive, the rear engine / rear drive base, and the lateral installation.

[Effect of device]

As described above, according to the present invention, since the unevenness of the spline groove in the drum of the transfer clutch is used as the driven side rotation sensor, the degree of freedom in mounting the pickup is increased, and the pickup can be mounted with high accuracy. The large-diameter shape of the drum also improves the rotational speed detection accuracy, which makes it possible to more accurately and appropriately control the torque of the transfer clutch.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing an example of a drive system to which the present invention is applied, and FIGS. 2 and 3 are sectional views showing an embodiment of a rotation sensor of the present invention. 19 …… Transfer clutch, 30 …… Hub, 31 …… Drum, 35 …… Spline groove, 36 …… Concave, 37 …… Convex, 39
...... Pickup, 42 …… Rear wheel rotation sensor

Claims (1)

[Scope of utility model registration request] 1. A structure in which a transfer clutch is provided in the middle of a front and rear wheel drive system, and an unevenness of a spline groove is formed on the outer periphery of a driven side drum of the transfer clutch, and a vehicle speed detection sensor is provided in a power transmission system of the front wheels. A pickup is installed outside the driven drum of the transfer clutch so as to face it, and a rotation sensor for detecting rotation is provided by the uneven portion of the driven drum and the pickup, and an output signal of the vehicle speed detection sensor and a rotation sensor are provided. Slip calculation means for calculating the slip ratio from the output value of
A driven wheel rotation sensor, characterized in that the transfer torque of the transfer clutch is controlled by the output value of the calculation means.