JP2523749Y2 - Drive coupling device for four-wheel drive - Google Patents

Description

[Detailed description of the invention] [Industrial application field] In the invention, the transmission of the driving force from one of the front and rear wheels to the other is performed by using the hydraulic pressure generated by a hydraulic pump formed between the two wheels. The present invention relates to a four-wheel drive drive coupling device.

[Conventional technology]

A four-wheel drive vehicle that travels by transmitting the driving force of the engine to both the front and rear wheels has been spotlighted as being able to realize stable traveling regardless of the road surface conditions, natural conditions such as weather, and traveling conditions. I'm taking a bath. Recent four-wheel drive vehicles are provided with a drive coupling device having a function of distributing a driving force to both wheels according to a rotational speed difference generated between front and rear wheels, and are configured to obtain a substantially always four-wheel drive state. In addition, a full-time four-wheel drive vehicle is mainly used, and one of such drive coupling devices uses a hydraulic pressure generated by a hydraulic pump.

FIG. 4 is a longitudinal sectional view showing the entire structure of a conventional drive coupling device for four-wheel drive. This is because a rotor 7 interlocked with one of the front and rear wheels is connected to a casing 8 interlocked with the other.
And a hydraulic pump (e.g., a vane pump) is housed therein, and the relative rotation corresponding to the rotational speed difference between the two wheels is controlled by the rotor 7.
Between the hydraulic pump and the casing 8 to generate hydraulic pressure inside the hydraulic pump. The hydraulic pressure generated at this time corresponds to the magnitude of the relative rotation, and acts between the rotor 7 and the casing 8 in order to suppress the relative rotation. A driving force corresponding to the rotational speed difference between the two wheels is transmitted to the other, and a desired four-wheel drive state is realized.

In such a drive coupling device, since not only the rotor 7 but also the casing 8 rotates, it is difficult to supply the hydraulic oil of the hydraulic pump from outside, and the casing 8 and the cylinder fitted to the outside thereof are difficult to supply. An oil storage portion T that rotates integrally with the casing 8 is formed between the body 37 and the oil storage portion T, and the sealed oil in the oil storage portion T is circulated and used as hydraulic oil for the hydraulic pump. In such an oil storage unit T, leakage of hydraulic oil and intrusion of liquid from outside the oil storage unit T are performed by an O-ring 9 fitted into a groove 90 provided around the casing 8 or the inside of the cylindrical body 37. I was preventing it.

[Problems to be solved by the invention]

In the conventional drive coupling device as described above, the oil storage portion T
Is sealed by an O-ring 9. In this case, a groove 90 for fitting the O-ring 9 is incorporated into the casing 8 or the cylindrical body 37 outside the casing 8 or inside the cylindrical body 37. It must be provided at a position where it does not interfere with the various members. However, in the case where the groove 90 is provided around the position thus restricted, the casing 8 and the cylindrical body are not provided.
37 has to be formed into a shape adapted to the position of the groove 90, and there is a problem that if the shape is complicated, the processing cost becomes high.

The present invention has been made in view of such circumstances, and provides a drive connection device for a four-wheel drive in which the arrangement position of a member for sealing hydraulic oil in an oil storage unit is not restricted and processing cost is low. The purpose is to:

[Means for solving the problem]

In the four-wheel drive drive coupling device according to the present invention, a rotor that rotates interlocking with one of the front and rear wheels is housed in a casing that rotates interlocking with the other, and the rotor is rotated according to a difference in rotation speed between the front and rear wheels. And a hydraulic pump for connecting the two wheels by hydraulic pressure generated in the casing, and hydraulic oil of the hydraulic pump is sealed in an oil storage portion formed between an outer periphery of the casing and a cylinder disposed outside the casing. In the four-wheel drive drive connection device, a sealing member having an L-shaped cross section is interposed between the cylindrical body and the casing at both axial ends of the cylindrical body.

[Action]

In the present invention, when a sealing member having an L-shaped cross section is fitted around the outer periphery of the casing at both axial ends of the cylindrical body, the outer surface of the sealing member (the surface opposite to the L-shaped bending direction) comes into close contact with the casing. Then, both shaft ends of the cylindrical body are connected to the inner surface (L
If the cylinder is attached in such a manner as to be clamped between the surfaces in the bending direction of the letter), the sealing member comes into close contact with the cylinder. Hydraulic oil in the oil storage section formed in this manner is sealed by sealing members at both axial ends of the cylinder.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof. FIG. 1 is a longitudinal sectional view showing the entire configuration of a four-wheel drive drive coupling device (hereinafter referred to as the present device) according to the present invention.

The device according to the present invention comprises an input shaft 1 that rotates in conjunction with one of the front and rear wheels, and an output shaft 2 that rotates in conjunction with the other of the front and rear wheels.
, Ie, a hydraulic pump that generates a hydraulic pressure corresponding to the rotational speed difference between the front and rear wheels. Normally, the driving force is transmitted from the input shaft 1 to the output shaft 2 via the generated hydraulic pressure. For example, a vane pump 3 as shown in the figure is used as the hydraulic pump.

In the vane pump 3, a rotor connected to an output shaft 2 as described later is coaxially rotatably housed in a casing connected to an input shaft 1 as described later. The casing of the vane pump 3 is formed with a thick hollow disc shape on both sides of a short cylindrical cam ring 31 having a circular outer circumference and an inner circumference formed by equally arranging a plurality of recesses around the circular shape. The pressure plate 32 and the side plate 33 forming a hollow disk are coaxially positioned, respectively, and the pressure plate 32 and the cam ring 31 are penetrated in the respective thickness directions to form the side plate.
A plurality of (only one is shown) fixing bolts 34,3 screwed to 33
These are integrally connected by 4. The input shaft 1 is hollow as shown by a two-dot chain line in the drawing. For connection with the input shaft 1, a large number of engaging teeth 36 are provided on the outer surface of the side plate 33 on its outer periphery. , 3
A short cylindrical connecting portion 35 having 6... Protrudes coaxially. The connection is achieved by externally fitting one end of the input shaft 1 to the connection portion 35 and engaging teeth 10, 10 formed on the inner periphery of the end.
And the engaging teeth 36 are engaged with each other, whereby the casing of the vane pump 3 rotates around the axis thereof in conjunction with the rotation of the input shaft 1.

On the other hand, the rotor of the vane pump 3 includes a rotor main body 30 having a short cylindrical shape having substantially the same length as the cam ring 31, and a hollow rotor shaft 4 as a rotation shaft of the main body. Rotor body 30
As is well-known, the coil spring 30b is provided with a rectangular flat plate-shaped vane 30a, which is provided with a plurality of grooves equally spaced in the circumferential direction with a predetermined depth in the radial direction, and is respectively housed so as to be able to advance and retreat. The cam ring 31 is housed inside the cam ring 31. The rotor shaft 4 is fitted in a hollow portion of the pressure plate 32 and the side plate 33 and is supported coaxially with the pressure plate 32 and the side plate 33.
30 is splined between the bearing positions. As a result, the rotor body 30 was positioned coaxially with the inside of the cam ring 31, and was surrounded on both sides by the pressure plate 32 and the side plate 33 at a position corresponding to the recess on the inner periphery of the cam ring 31. A plurality of pump chambers are formed. The output shaft 2 shown by a two-dot chain line in the figure is fitted in the hollow portion of the rotor shaft 4, and both are coaxially spline-coupled. Therefore, the rotor body 30 rotates in conjunction with the rotation of the output shaft 2, and the input shaft 1 and the output shaft are provided between the cam ring 31 and the rotor body 30, that is, between the casing of the vane pump 3 and the rotor. 2, that is, relative rotation corresponding to the difference in rotational speed between the front and rear wheels occurs, and hydraulic pressure is generated in the pump chamber as described later.

A thin-walled cylindrical body 37 is fitted on the outside of the casing so as to surround substantially the whole of the casing.
Is enclosed in an oil storage portion T formed in an annular shape between the inner periphery of the cylindrical body 37 and the outer periphery of the casing. The hydraulic oil in the oil storage portion T is sealed by a sealing member 6 made of a fluorine-based rubber seal ring having an L-shaped cross section, which will be described later, interposed between the outer circumference of the pressure plate 32 and the pressure plate 33 and the cylinder 37. , 6.

The pressure plate 32 is provided with a pair of check valves (not shown) which are formed in the oil storage portion T so that one end thereof is opened in a radially inward direction, and allow only the flow in the same direction. A plurality of oil passages (not shown) are formed. These oil passages communicate with the pump chamber between the pair of check valves, respectively, and communicate with the bottoms of the storage grooves of the vanes 30a, 30a,. It functions as a suction oil passage or a discharge oil passage depending on the direction of relative rotation of.

The hollow portion of the pressure plate 32 penetrates through the pressure plate 32 in the radial direction, and communicates with the oil storage portion T through a return hole 40 provided with the opening / closing means 5 in the middle thereof. The return hole 40 is formed by coaxially connecting a small diameter hole 40a on the annular groove 24 side and a large diameter hole 40b on the oil storage portion T side. The opening / closing means 5 mounted on the return hole 40 includes a spool 51 which moves by receiving a hydraulic pressure on the discharge side of the pump chamber,
And a stopper 52 for limiting the moving range of
It is urged in a direction away from each other by a coil spring 53 interposed between them.

The spool 51 has a shape in which a cylindrical body having a smaller diameter than this is coaxially connected to one side of a thin-walled disk, and at the axial center position,
An oil passage hole 510 penetrating in the axial direction is formed. The cylindrical portion of the spool 51 is inserted into the small-diameter hole 40a with its end face facing the annular groove 24 side.
1 is slid in the axial direction by being guided by this fitting portion. At this time, the disk portion of the spool 50 is in a state of being loosely inserted into the large-diameter hole 40b. On the other hand, like the spool 51, the stopper 52 has a shape in which a small-diameter cylinder is continuously provided on one side of the disk, and a snap ring in which the other side of the disk portion is engaged with the inner periphery of the large-diameter hole 40b. It is fixed to the oil storage section T in such a manner that it is restrained by the cylinder 54 and the end face of the cylindrical section faces the disk section of the spool 51. The coil spring 53 is loosely fitted outside the cylindrical portion of the stopper 51. Both ends of the coil spring 53 are pressed against the disk portion of the spool 51 and the disk portion of the stopper 52, respectively. A predetermined urging force in a direction away from each other is applied between them.

Further, in the opening / closing means 5 configured as described above, the sliding position of the spool 51 is determined by the oil pressure in the annular groove 24 acting on one side, that is, the oil pressure on the discharge side of the pump chamber 40, and the oil pressure acting on the other side. Determined by the balance with the biasing force of the coil spring 53,
When the hydraulic pressure is low and the force acting on the spool 51 is lower than the urging force of the coil spring 53, the spool 51 is at the position shown in FIG. The gap is secured, and the opening end of the oil passage hole 50a into the oil storage portion T is opened. On the other hand, the hydraulic pressure exceeds the urging force of the coil spring 53, and at the same time, the stopper 52 starts sliding toward the stopper 52.
This is caused by the increase in the hydraulic pressure until it is suppressed by the contact between the disc portion and the end surface of the column portion of the stopper 52. When the contact occurs, the opening end of the oil passage hole 50a into the oil storage portion T is closed at the end face of the stopper 51, and the communication between the annular groove 24 and the oil storage portion T is cut off. That is, the opening / closing means 5 performs an operation of opening the return hole 40 when the oil pressure in the annular groove 24 is low, and closing the return hole 40 when the oil pressure is high. In addition,
Since the passage area of the return hole 40 is governed by the area of the throttle portion at the end of the oil passage hole 50a, the sliding of the spool 50 is continued until the spool 50 and the stopper 51 are sufficiently close by the sliding. Regardless of the position, the passage area is maintained substantially constant, and then decreases sharply to close.

Thus, a rotational speed difference occurs between the front and rear wheels, and the relative rotation between the rotor of the vane pump 3 and the casing, that is, between the rotor body 30 and the cam ring 31, at a speed corresponding to the rotational speed difference. Occurs, hydraulic oil flows into the pump chambers formed therebetween from the oil storage unit T via the oil passages communicating with each other on the upstream side in the relative rotation direction. Sealed between adjacent vanes 30a, 30a,
The pressure is increased by being rotated by the rotation of the rotor body 30, and is discharged into the oil passages communicating with the respective pump chambers on the downstream side in the relative rotation direction, flows in the oil passages radially inward, and the vanes 30a , 30a... Are returned to the oil storage portion T via the return hole 40. The oil introduced into the bottom of the storage groove presses each of the vanes 30a, 30a... In the radially outward direction by the urging force of the coil spring 30b, and presses the respective tips against the inner peripheral surface of the cam ring 31 so as to be adjacent to each other. Vane 30
It functions to ensure the sealing of the hydraulic oil between the a and 30a. Due to such circulation of hydraulic oil, the inside of each pump chamber is
A hydraulic pressure corresponding to the magnitude of the relative rotation is generated against the flow path resistance in the circulation path, mainly the flow path resistance in the opening / closing means 5 for the return hole 40, and the hydraulic pressure is generated between the rotor body 30 and the cam ring 31. The driving force corresponding to the rotational speed difference between the front and rear wheels is transmitted from the input shaft 1 connected to the latter to the output shaft 2 connected to the former through the hydraulic pressure acting to suppress the relative rotation between the two. Is transmitted.

FIG. 2 is an enlarged sectional view showing a mounting state of the sealing members 6, 6 which is a feature of the device of the present invention, and FIG. 3 is a front view of the sealing members 6, 6. Pressure plate 32 and side plate 33
Are sealed with sealing members 6, 6
Is cut out by a predetermined depth in the axial length direction by a width equal to the height of the L-shape. The sealing members 6, 6 are fitted around the outer periphery of the notch in such a manner that the L-shaped corners are located at the corners of the respective notches of the pressure plate 32 and the side plate 33. Then, as described above, the fixing bolts 34, 3
When the pressure plate 32, the cam ring 31, and the side plate 33 are integrally connected by 4..., As described above, the respective inner surfaces (L-shaped) of the sealing members 6, 6 that are externally fitted to the pressure plate 32 and the side plate 33 are used. The pressure plate is positioned by positioning the cylinder 37 so that both ends in the width direction of the cylinder 37 are sandwiched between the corners of the surface in the bending direction).
32, the cam ring 31, and the side plate 33 are combined. Thus, the cylinder 37 is provided outside the casing, and the cylinder 37 and the outer periphery of the casing constitute an oil storage portion T. In the oil storage unit T thus configured, the sealing member
The inner surfaces of 6, 6 are in close contact with the cylindrical body 37, and the outer surface (the surface opposite to the L-shaped bending direction) is a pressure plate.
The oil storage portion T is sealed because it is in close contact with the side plate 32 and the side plate 33.

As described above, the sealing members 6, 6 are adapted to be fitted around the outer circumferences of the pressure plate 32 and the side plate 33, and it is not necessary to provide a groove for the mounting around the casing. There is no interference with members such as the opening / closing means 5 disposed inside.

In this embodiment, the sealing members 6, 6 are separate members from the cylinder 37. However, the present invention is not limited to this, and the sealing members 6, 6 are integrated with the cylinder 37 in advance by baking. May be.

〔effect〕

As described in detail above, in the device of the present invention, the sealing member for the hydraulic oil in the oil storage section has an L-shaped cross section, and when this is interposed between the cylindrical body and the casing, a groove for mounting the sealing member is formed in the casing. The present invention has excellent effects, such as no need to form, so that the arrangement position of the sealing member is not restricted, the shape of the cylinder or the casing is simplified, and the processing cost is reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entire configuration of the device of the present invention, FIG. 2 is an enlarged sectional view showing a mounting state of a sealing member which is a feature of the device of the present invention, FIG. 3 is a front view of the sealing member, and FIG. Conventional 4
It is a longitudinal section showing the whole wheel drive drive connection device composition. 1 input shaft 2 output shaft 3 vane pump 6
…… Sealing member, 30 …… Rotor body, 32 …… Pressure plate, 33 …… Side plate, 37 …… Cylinder

Claims (1)

(57) [Scope of request for utility model registration] A rotor which rotates in conjunction with one of the front and rear wheels is housed in a casing which rotates in conjunction with the other, and the two wheels are connected by a hydraulic pressure generated inside the casing in accordance with a rotational speed difference between the front and rear wheels. A four-wheel drive drive coupling device, comprising: a hydraulic pump having a hydraulic pump, wherein hydraulic oil of the hydraulic pump is sealed in an oil reservoir formed between an outer periphery of the casing and a cylinder disposed outside the casing. A drive coupling device for four-wheel drive, wherein a sealing member having an L-shaped cross section is interposed between the cylindrical body and the casing at both axial ends of the cylindrical body.