JPH086761B2 - Input torque proportional type rotation difference sensitive joint and differential limiting device to which this rotation difference sensitive joint is applied - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an input torque proportional rotation difference sensitive joint applied as a differential limiting device, a transfer device of a four-wheel drive vehicle and the like, and this input torque proportional rotation. The present invention relates to a differential limiting device to which a differential sensitive joint is applied.

(Prior Art) Conventionally, a joint described in Japanese Patent Application Laid-Open No. 63-101567 is known as a control type rotation difference sensitive joint for changing and controlling a transmission torque characteristic.

In this conventional source, there are a first rotation shaft and a second rotation shaft that are coaxially rotatably arranged, and the first rotation shaft and the second rotation shaft.
The flow rate discharged according to the relative rotation speed difference of the rotating shaft is converted into fluid pressure by the flow rate regulation by the orifice.
A rotation difference sensitive joint which converts this fluid pressure into a transmission torque between both shafts, and an orifice portion of the rotation difference sensitive joint,
And a spool arranged to change the orifice opening area by an external actuator.

(Problems to be Solved by the Invention) However, in such a conventional control type rotational differential sensing joint, since the orifice opening area is changed by sliding the spool by an external actuator, There was a problem to enumerate.

Since the spool that is placed in a harsh environment that rotates at high speed must be configured to have a sliding stroke, the layout of the actuator and the layout of the transmission mechanism that transmits the actuator operation to the spool are very difficult, and also in terms of configuration. It gets complicated.

In addition to the spool that changes the orifice opening area, an electronic control circuit that outputs a control command to the actuator, an actuator, and a transmission mechanism are required, which increases the cost.

Since the electronic control system is included in the configuration rather than the purely mechanical configuration, the cause of failure is extremely large, and maintenance or replacement of parts or maintenance to confirm normal operation is required.

The present invention has been made by paying attention to the above problems, and is advantageous in configuration, cost, and maintenance in an input torque proportional type rotation difference sensitive joint applied as a differential limiting device or a transfer device. The first issue was to develop a joint that achieves automatic control of torque transmission characteristics according to the input torque. Applying this input torque proportional type rotation difference sensitive joint, a differential configuration that corresponds to the input torque with a compact structure is applied. A second object is to provide a differential limiting device that achieves automatic control of torque characteristics.

(Means for Solving the Problem) In order to solve the above-mentioned first problem, in the input torque proportional-type rotation difference sensing joint according to claim 1, the orifice opening area is changed by utilizing the input torque from the drive gear. It was a mechanical means.

That is, the first rotating shaft and the second rotating shaft which are coaxially rotatably arranged with each other, and the first rotating shaft and the second rotating shaft are engaged with each other in the rotating direction and in the axial direction with respect to each other. A first slide member and a second slide member provided so as to enable a fixed stroke.
Provided between the slide member and the first and second slide members, the flow rate discharged according to the relative rotational speed difference between the first and second rotary shafts is converted into fluid pressure by flow rate regulation by an orifice, and A rotation difference sensitive joint that converts this fluid pressure into a transmission torque between both shafts, a drive gear that meshes with one of the first and second slide members and applies a meshing force in the axial direction according to the input torque, A spring member that maintains the axial relative positional relationship between the first and second slide members and an axial fixed member are provided, and the orifice opening area is changed by relative displacement accompanying the slide stroke of the first and second slide members. And a valve member arranged to do so.

In order to solve the second problem, in the differential limiting device according to the second aspect, a means is provided in which the input torque proportional type rotation difference sensing joint according to the first aspect is incorporated in the differential device.

That is, the first rotary shaft and the second rotary shaft are used as output shafts for the left and right wheels or the front and rear wheels, and the first slide member and the second slide member are connected to each of the output shafts. The drive gear is a pinion that meshes with a side gear formed in the housing member, a differential case into which the engine driving force is input, a pinion shaft supported by the case, and a pinion rotatably supported by the pinion shaft. And a pair of side gears meshing with the pinion, the input torque proportional type rotation difference sensing joint according to claim 1 is incorporated in a built-in state.

(Operation) The operation of the invention described in claim 1 will be described.

The transmission torque characteristics of the input torque proportional type rotation difference sensitive joint will be explained. In the rotation difference sensitive joint, when there is no relative rotation between the first and second rotating shafts, the transmission torque between the first and second rotating shafts is large. When the relative rotation of the first and second rotary shafts does not occur, the flow rate discharged according to the relative rotational speed difference is converted into the fluid pressure by the flow rate regulation by the orifice. The torque is converted into the transmission torque between the shafts, and the transmission torque corresponding to the relative rotational speed difference is generated.

And, in this input torque proportional type rotation difference sensitive joint,
The first slide member and the second slide member, which are engaged in the rotational direction and are capable of moving a predetermined amount in the axial direction, mesh with one of the first and second slide members, and the axial direction depends on the input torque. Since a drive gear that gives a meshing force to the shaft, a spring member that maintains the relative axial positional relationship between the first and second slide members, and a valve member that is provided on the axial fixed member, When an axial meshing force is applied to one of the second slide members according to the input torque, the first and second slide members both make a slide stroke, and the relative displacement accompanying this stroke causes the valve member to move. Changes the orifice opening area.

That is, since the transfer torque characteristic is determined by the orifice opening area in the rotation difference sensitive joint, the transfer torque characteristic with respect to the relative rotation speed difference is automatically changed according to the input torque.

 The operation of the second aspect will be described.

In the differential limiting device according to claim 2, the differential limiting torque is generated according to the differential rotational speed difference between both output shafts, and the differential limiting torque characteristic with respect to the differential rotational speed difference is the input torque from the pinion. Automatically changed accordingly.

For example, if the device is such that the orifice opening area is large when the input torque is small and the orifice opening area is changed to a smaller area as the input torque increases, the input torque becomes small when the vehicle is stopped or at an extremely low speed such as garage parking. Since the increase gain of the differential limiting torque with respect to the differential rotational speed difference is low, the vehicle does not behave strangely and the malfunction of the anti-skid braking system (ABS) is prevented.

Further, when the vehicle is traveling at a high speed with the accelerator pedal depressed, the input torque is large and the gain of the differential limiting torque is high with respect to the differential rotation speed difference, so the tail swing is prevented and the high-speed traveling stability of the vehicle is ensured. It

(Example) Hereinafter, the present invention will be described based on an example shown in the drawings.

 First, the configuration of the embodiment will be described.

FIG. 1 is a sectional view showing a differential limiting device of an embodiment,
An input torque proportional rotation difference sensitive joint 2 as a differential limiting means for exerting a differential limiting function is assembled in a differential device 1 for exerting a differential function in a built-in state.

As the differential device 1, a differential case 10 to which a driving force is input via a drive pionion 3 and a ring gear 4, and a pinion 12 (driving gear) rotatably supported via a pinion shaft 11, The pinion
A pair of side gears 13, 14 meshing with 12 and the side gear 1
Two output shafts for left and right drive wheels 15,16 connected to 3,14
(First rotating shaft, second rotating shaft).

The driving force is transmitted to the output shafts 15 and 16 evenly when no differential rotation occurs, and when the differential rotation occurs, only the differential limiting torque by the input torque proportional type rotation difference sensing joint 2 is generated. The driving force is transmitted from the high rotation side to the low rotation side.

As shown in FIGS. 1 and 2, the input torque proportional rotation difference sensitive joint 2 is a cam housing in which a side gear 14 is formed while being splined to one of the output shafts 15 and 16. The rotor 30 (second slide member, housing member), the cam surface 21 formed on the inner surface of the cam housing 20, and the rotor 30 (second slide) spline-coupled to the other output shaft 16 to which the side gear 13 is spline-coupled. Members, rotor members), and provided on the rotor 30,
A driving piston 40 in a radial arrangement that reciprocates in the radial direction while slidingly contacting the cam surface 21 by relative rotation, a cylinder chamber 50 that changes in volume as the driving piston 40 reciprocates, and communicates with each cylinder chamber 50. A radial arrangement of the balance oil passage 60, a regulator oil passage 80 that communicates the accumulator chamber 70 with each cylinder chamber 50, and an orifice 90 provided in a portion from the balance oil passage 60 toward the accumulator chamber 70 are basically provided. It is equipped as a configuration.

Next, a characteristic configuration of the input torque proportional type rotation difference sensitive joint 2 will be described.

The cam housing 20 is provided so as to engage with the output shaft 15 through a cam housing cover 22 by spline coupling in the rotational direction and to be able to stroke a predetermined amount in the axial direction.

Further, the rotor 30 is provided so as to engage with the output shaft 16 in the rotational direction by a spline connection and to be able to stroke a predetermined amount in the axial direction.

A side gear 14 is formed integrally with the cam housing 20, and a meshing component force is applied to the side gear 14 in the axial direction from the pinion 12 according to the input torque.

The disc spring 91 (spring member) for maintaining the axial relative positional relationship between the cam housing 20 and the rotor 30 is a cam housing cover.
It is provided between 22 and the rotor 30.

The orifice 90 is formed in an orifice piece 92 having a valve hole 92a, and in this valve hole 92a,
A spool valve 93 (valve member) is provided in a state where one end face is pressed against the cam housing cover 22 (axially fixed member), and the orifice piece 92 and the spool valve 93 associated with the sliding stroke of the cam housing 20 and the rotor 30 are provided. The other end surface of the spool valve 93 is arranged so as to change the orifice opening area by the relative displacement of.

In FIGS. 1 and 2, 31 is a cylinder hole, 32 is a cylinder portion, 41 is a seal ring, 71 is an accumulator piston, 72 is a spring retainer, 73 is a spring, 74 is a piston seal 74, 75 is a relief hole. 75 and 81 are one-way valves.

 Next, the operation of the embodiment will be described.

When driving straight on low and medium speeds on dry asphalt roads, etc., and when there is no differential rotation speed difference between the left and right wheels connected to the output shafts 15 and 16, the cam housing 20 and rotor
Since there is no relative rotation with 30 and the driving piston 40 does not reciprocate in the radial direction, in principle there is no differential limiting torque generated, and the engine driving force input from the differential case 10 is equal to the output shafts 15 and 16. Will be distributed.

However, even when relative rotation does not occur between the left and right wheels,
When traveling straight on a highway at high speed, the output shafts 15 and 16
The centrifugal force acts on the driving piston 40 provided on the rotor 30 that rotates at a high speed with the rotation of the driving piston 40, and the driving piston 40 is pressed against the cam surface 21 by this centrifugal force. Occurs.

In addition, when driving on rough roads or when one wheel is stuck, the output shaft 15,16
When a differential rotation speed difference occurs between the left and right wheels connected to
Relative rotation is also generated in the cam housing 20 and the rotor 30, and due to this relative rotation, the driving piston 40 slidingly contacting the cam surface 21 reciprocates in the radial direction. When attempting to reduce the volume of the cylinder, the pressure in the cylinder chamber 50 increases due to the flow resistance generated by the outflow regulation by the orifice 90, and the hydraulic pressure obtained by multiplying the generated hydraulic pressure and the pressure receiving area of the piston 40 cams the driving piston 40. The force acts on the surface 21, and this force acts as a differential limiting torque, and the differential is limited so that the distribution of the driving force is reduced on the high-speed rotation side and increased on the low-speed rotation side.

That is, the differential limiting torque characteristic with respect to the differential rotational speed difference shows a characteristic that the differential limiting torque increases with a quadratic function curve as the differential rotational speed difference increases, as shown in FIG.

The input torque proportional type rotation difference sensing joint 2 is provided with a cam housing 20 and a rotor 30 which are engaged in the rotation direction and are capable of a predetermined stroke in the axial direction, and a side gear 14 of the cam housing 20. Pinion 12 that gives a meshing component force in the axial direction according to meshing and input torque
A disc spring 91 for maintaining the relative axial positional relationship between the cam housing 20 and the rotor 30, and a spool valve 93 provided on the housing cover 22.

Therefore, when the meshing component force in the axial direction corresponding to the input torque is applied from the pinion 12 to the cam housing 20, both the cam housing 20 and the rotor 30 move to the left in the arrow in FIG. When the input torque is reduced, the cam housing 20 and the rotor 30 both slide in the right direction of the arrow in FIG. 3, so that the cam housing 20 and the rotor 30 are arranged at positions corresponding to the input torque. The orifice opening area is changed by the relative positional relationship between the piece 92 and the spool valve 93.

That is, in the rotation difference sensitive joint, the differential limiting torque characteristic is determined by the orifice opening area. Therefore, as shown in FIG. 4, when the input torque is small, the differential limiting torque characteristic with respect to the differential rotational speed difference is the differential limiting torque characteristic. It shows a characteristic that the increase gain of the differential limiting torque with respect to the rotation speed difference is low, and shows a characteristic that the increase gain of the differential limiting torque with respect to the differential rotation speed is high when the input torque is large. Will be changed.

For example, if the device is such that the orifice opening area is large when the input torque is small and the orifice opening area is changed to a smaller area as the input torque increases, the input torque becomes small when the vehicle is stopped or at an extremely low speed such as garage parking. The characteristic that the increase gain of the differential limiting torque with respect to the differential rotational speed difference is low, the vehicle does not behave strangely and the error movement of the anti-skid braking system (ABS) is prevented.

Further, when the vehicle is traveling at a high speed by stepping on the accelerator, the input torque is large and the increase gain of the differential limiting torque with respect to the difference in rotational speed is high, so swinging of the tail is prevented and high-speed traveling stability of the vehicle is ensured. .

As described above, the differential limiting device according to the embodiment has the features listed below.

The input torque proportional type rotation difference sensing joint 2 has a pure mechanical structure that changes the orifice opening area by using the input torque from the pinion 12, so it is structurally and cost-effective compared to the case where the orifice opening area is changed by an external actuator. While being advantageous in terms of physical and maintenance,
It is possible to achieve automatic control of the differential limiting torque characteristic according to the input torque.

Since the input device is a device in which the input torque proportional type rotational difference sensitive joint 2 is incorporated in the differential device 1, it has a compact structure, but when the input torque is small, the gain of the differential limiting torque with respect to the differential rotational speed difference is increased. To obtain a differential limiting torque characteristic according to the input torque, such that a low gain characteristic is obtained and a high gain of the differential limiting torque with respect to the differential rotation speed difference is obtained when the input torque is large. You can

As a result, when the vehicle is stopped or at an extremely low speed such as entering a garage, the input torque is small and the gain of the differential limiting torque with respect to the differential rotation speed difference is low, so the vehicle does not behave strangely. The malfunction of the anti-skid braking system (ABS) is prevented.

In addition, when driving at high speed with the accelerator depressed, the input torque is large and the gain of the differential limiting torque against the differential rotation speed difference is high, so backlash is prevented and high-speed running stability of the vehicle is ensured. To be done.

The embodiment of the present invention has been described in detail above with reference to the drawings.
The specific configuration is not limited to this embodiment, and even if there are design changes and the like within the scope of the present invention, they are included in the present invention.

(Effects of the Invention) As described above, according to the present invention as set forth in claim 1, in the input torque proportional type rotation difference sensing joint applied as the differential limiting device or the transfer device, the input torque by the drive gear is used. Since it is a purely mechanical means to change the orifice opening area by utilizing the structure, it is advantageous in terms of configuration, cost and maintenance, and it is possible to provide a joint that achieves automatic control of torque transmission characteristics according to input torque. Is obtained.

Further, in the differential limiting device according to the second aspect, the input torque proportional type rotation difference sensitive joint according to the first aspect is incorporated into the differential device as a means, so that the input torque is compact. It is possible to provide an effect that it is possible to provide a differential limiting device that achieves automatic control of differential limiting torque characteristics according to the above.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional plan view showing a differential limiting device to which an input torque proportional type rotational difference sensitive joint of an embodiment of the present invention is applied, and FIG. 2 is a vertical sectional view showing a rotational difference sensitive joint portion taken along line I-I in FIG. FIG. 4 is a front view, FIG. 3 is an operation explanatory view for explaining an orifice opening area changing operation which is proportional to the input torque, and FIG. 1 …… Differential device 2 …… Input torque proportional type rotation difference sensitive joint 10 …… Differential case 11 …… Pinion shaft 12 …… Pinion (driving gear) 13,14 …… Side gear 15 …… Output shaft (1st rotation) 16) Output shaft (second rotary shaft) 20 ... Cam housing (first slide member, housing member) 22 ... Housing cover (axial fixing member) 30 ... Rotor (second slide member, rotor member) ) 40 Driving piston 50 Cylinder chamber 60 Balance oil passage 70 Accumulator chamber 80 Regulator oil passage 90 Orifice 91 …… Disc spring (spring member) 92 …… Orifice piece 93 …… Spool Valve (valve member)

Claims (2)

[Claims] 1. A first rotating shaft and a second rotating shaft coaxially rotatable relative to each other, and axially engaging with the first rotating shaft and the second rotating shaft in the rotating direction. The first slide member and the second slide member are provided so as to be able to stroke a predetermined amount, and are provided between the first and second slide members, and discharge is performed according to the relative rotational speed difference between the first and second rotary shafts. The rotational difference sensitive joint which converts the generated flow rate into a fluid pressure by regulating the flow rate by an orifice, and further converts this fluid pressure into a transmission torque between both shafts. A drive gear that applies a meshing force in the axial direction in accordance with the torque, a spring member that maintains the axial relative positional relationship between the first and second slide members, and a first gear provided on the axial fixed member. For slide stroke of slide member Nau relative displacement by the input torque proportional rotation difference sensitive coupling, characterized in that it comprises a and a valve member disposed so as to change the orifice opening area. 2. A housing member in which the first rotary shaft and the second rotary shaft are output shafts for the left and right wheels or the front and rear wheels, and the first slide member and the second slide member are connected to the both output shafts, respectively. And a rotor member, the drive gear is a pinion meshing with a side gear formed in the housing member, a differential case into which the engine driving force is input, a pinion shaft supported by the case, and a rotatably supported by the pinion shaft 5. A differential limiting device comprising the differential gear having a pinion and a pair of side gears meshing with the pinion, wherein the input torque proportional type rotation difference sensing joint according to claim 1 is incorporated in a built-in state.