JPS6253376B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transfer device for a four-wheel drive power transmission device used in vehicles such as automobiles, and particularly relates to a transfer device including a hydraulically actuated clutch. .

BACKGROUND OF THE INVENTION A four-wheel drive power transmission device used in a vehicle such as an automobile generally uses an output shaft of a transmission device and a wheel drive shaft to selectively transmit power from a prime mover to front wheels or rear wheels, which are selectively driven wheels. The transfer device includes a clutch that selectively connects the transfer device.

It has been proposed to switch and drive the clutch of the above-mentioned transfer device using a hydraulic servo device, and to perform four-wheel drive switching under hydraulic control, especially when the transmission is a hydraulically controlled automatic transmission. By using the hydraulic pressure for shift control of the automatic transmission as the hydraulic pressure supplied to the hydraulic servo device, the transfer device can be hydraulically controlled without requiring a dedicated hydraulic pressure supply source.

However, a hydraulic control valve that controls the supply and discharge of hydraulic pressure to and from a hydraulic chamber of a hydraulic servo device is combined with a hydraulic control device for speed change control of an automatic transmission. If provided at the bottom of the transmission case, the hydraulic chamber of the hydraulic servo device of the transfer device provided in the extension housing connected to one end of the transmission case and the hydraulic control valve. In other words, the length of hydraulic pressure transmission between the hydraulic control valve and the hydraulic servo device becomes longer, and the operation of the hydraulic servo device is delayed relative to the operation of the hydraulic control valve, resulting in poor responsiveness. This makes it difficult to obtain good switching performance of the transfer device.

OBJECT OF THE INVENTION The present invention provides a hydraulically controlled four-wheel drive power transmission device that has excellent switching response, has a simple structure, has a high degree of freedom in miniaturization, and is also easy to assemble and maintain. The purpose is to provide transfer equipment.

According to the present invention, it is an object of the present invention to provide a clutch that is incorporated in an extension housing attached to one end of a transmission case and selectively connects an output shaft of a transmission and a wheel drive shaft; a hydraulic servo device for connecting and disconnecting the clutch, the hydraulic servo device having a hydraulic chamber defined in a part of the extension housing in cooperation with the extension housing; is configured such that hydraulic pressure is supplied and discharged from a hydraulic control valve attached to the one end of the transmission case through an oil passage formed in the one end of the transmission case and the extension housing. This is achieved by a transfer device of a four-wheel drive power transmission device such as the one shown in FIG.

Effects of the Invention In the transfer device of the four-wheel drive power transmission device according to the present invention, the hydraulic control valve is provided at the connection end of the transmission case with the extension housing housing the transfer device, and Since the hydraulic control valve and the hydraulic chamber of the hydraulic servo device are directly connected through the oil passage connected to the connection end of the transmission case and the extension housing, the hydraulic control valve and the hydraulic chamber are The length of the connected oil passage is short, so that the hydraulic servo device operates relatively quickly in response to the operation of the hydraulic control valve, and switching of the transfer device is performed with good responsiveness. In addition, since the hydraulic control valve is provided at the end of the transmission case connected to the extension housing, it can be easily assembled and removed with the extension housing removed from the transmission case. , and its maintenance work is easily performed.

DESCRIPTION OF EMBODIMENTS The invention will now be described in detail by way of embodiments with reference to the accompanying drawings.

The attached figure is a longitudinal sectional view showing one embodiment of a transfer device for a four-wheel drive power transmission device according to the present invention. In the figure, reference numeral 1 indicates an extension housing, and the extension housing is connected to the transmission case 4 at one end.
0 by a bolt (not shown). The extension housing 1 includes a connecting shaft 2 that is drivingly connected to one end of an output shaft of a gear transmission incorporated in a transmission case 40, and a rear wheel drive shaft that is drivingly connected to a rear wheel (not shown). 3 on the same axis.

The connecting shaft 2 has an end shaft portion 4 that engages with a bearing hole 5 extending in the axial direction at one end of the rear wheel drive shaft 3, and the end shaft portion is rotated by the rear wheel drive shaft 3. The rear wheel drive shaft 3 is rotatably supported by the extension housing 1 by means of a radial ball bearing 6.

The connecting shaft 2 integrally includes a clutch member 8 having external teeth 7 at an end adjacent to the one end of the rear wheel drive shaft 3. The rear wheel drive shaft 3 has external teeth 9 at the one end.
It integrally has a clutch member 10 having a.
The outer teeth 7 and 9 are concentric with each other and have pitch circles of the same diameter, and the outer teeth 9 have a clutch sleeve 11.
The inner teeth 12 of the two are in mesh with each other. clutch sleeve 1
1 is movable in the axial direction of the rear wheel drive shaft 3 between a cutting position where the internal teeth 12 mesh only with the external teeth 9 and a connecting position where the internal teeth 12 mesh with both of the external teeth 9 and 7. The connecting shaft 2 and the rear wheel drive shaft 3 are connected in a rotational power transmission relationship when the connecting shaft is moved to the left in the figure from the position shown in the figure and is in the connecting position. .

Chamfer portions 12a and 7a are provided at the ends of the meshing engagement between the internal teeth 12 of the clutch sleeve 11 and the external teeth 7 of the clutch member 8, respectively.

The inner race 22a of the radial ball bearing 22 is attached to the collar 29 on the outer periphery of the clutch sleeve 11.
and is fixed by a snap spring 30.
A connecting sleeve 18 is fixed to the outer periphery of the outer race 22b of the radial ball bearing 22 by a snap spring 31. That is, the connecting sleeve 18 is attached to the clutch sleeve 11 by means of a radial ball bearing 22 so as to be rotatable but fixed in the axial direction.

The extension housing 1 defines an annular cylinder bore 13 concentric with the connection shaft 2 and the rear wheel drive shaft 3 on the inside thereof by an outer cylinder part 1a and an inner cylinder part 1b which are concentric with each other. An annular piston 14 for a hydraulic servo is engaged to be movable in the axial direction. The piston 14 has oil seals 15 and 1 on one side, that is, on the side of the clutch member 10 (the right side in the figure) compared to the clutch member 8.
6 defines a cylinder chamber (hydraulic chamber) 17 which is kept in a liquid-tight state. The piston 14 has a protruding portion 14a on the other side that protrudes in the axial direction from the inner cylinder portion 1b, and the protruding portion is in sliding contact with the outer circumferential portion of the connecting sleeve 18 at the inner circumferential portion so as to be movable in the axial direction. Further, an annular stopper plate 20 is fixed to the tip of the protrusion by a bolt 19. Although not shown in the figure, the piston 14 has a protrusion that engages with an axial groove provided in the extension housing, and the piston is prevented from rotating by the engagement between the protrusion and the groove. ing.

The stopper plate 20 partially has a portion in the circumferential direction that faces the end of the piston 14 at a predetermined interval in the axial direction and defines a gap, and the stopper plate 20 has a portion that faces the end of the piston 14 at a predetermined interval in the circumferential direction. A flange piece 18a that partially extends from the connecting sleeve 18 in the circumferential direction is located in the gap between the connecting sleeves 18 and 18 so as to be movable in the axial direction. A buffer compression coil spring 21 is disposed with a predetermined preload between the flange piece 18a and the bottom of the bottomed hole 14b provided in the piston 14. and the connecting sleeve 18 are urged away from each other in the axial direction. That is, the piston 14 and the connecting sleeve 18 are configured to be able to move relative to each other by a predetermined distance in the axial direction against the spring force of the buffer compression coil spring 21. The permissible relative movement in the axial direction between the piston 14 and the connecting sleeve 18 is smaller than the full stroke of the piston 14, and the buffer compression coil spring 21
When the piston 14 is compressed by a predetermined amount, the piston 14 directly contacts the flange portion 18a of the connecting sleeve 18 at its tip, and can directly drive the flange portion 18a to the left in the figure.

In order to absorb misalignment between the piston 14 and the output shaft 3, a radial gap 25 is provided at the fitting portion between the inner race 22b of the radial ball bearing 22 and the clutch sleeve 11.

An annular spring retainer 2 is installed inside the extension housing 1 by a snap spring 31.
3 is fixed. A return compression coil spring 24 is attached with a predetermined preload between the spring retainer 23 and the bottom of the bottomed hole 14c provided in the piston 14. The return compression coil spring 24 urges the piston 14 to the right in the figure, that is, in a direction from the connection position toward the disconnection position. The return compression coil spring 24 is made of a spring weaker than the buffer compression coil spring 21, and its preload is smaller than the preload of the buffer compression coil spring 21.

the one end of the transmission case 40;
That is, a hydraulic control valve 34 for hydraulic servo control is attached to the end connected to the extension housing 1. The hydraulic control valve 34 is supplied with hydraulic pressure from a hydraulic supply source (not shown) provided in the transmission case 40 through an oil passage (not shown) formed in the transmission case 40, and can be switched manually or electromagnetically. Port 3
5 is selectively connected to an oil pressure supply source and an oil drain port. An oil passage 42 is formed at one end of the connection end of the transmission case 40 and is directly connected to the port 35 . It communicates via passages 43 and 44 with a connection port 45 opened at the end surface connected to the extension housing 1. The extension housing 1 has a connection port 36 that is aligned with the connection port 45 on the end surface connected to the transmission case 40, and the connection port is provided in the extension housing 1 and connected to the cylinder chamber through oil passages 37 and 38. It is connected to 17. As shown, when one end of the extension housing 1 is connected to one end of the transmission case 40, the connection ports 36 and 45 are aligned and communicate with each other, thereby causing the port of the hydraulic control valve 34 35 is oil passage 42, 43, 4
4. It is communicated and connected to the cylinder chamber 17 via connection ports 45, 36 and oil passages 37, 38. In the figure, numerals 39 and 46 are blind plugs that close the machined holes of the oil passages 38 and 43, respectively.

Next, the operation of the transfer device configured as described above will be explained.

FIG. 1 shows a state in which the hydraulic control valve 34 is in the oil draining position, no hydraulic pressure is supplied to the cylinder chamber 17, and the clutch sleeve 11, together with the piston 14 and the connecting sleeve 18, is in the disconnected position on the right side of the figure. It shows. In this state, when the hydraulic control valve 34 is switched from the oil drain position to the oil supply position to perform four-wheel drive, the hydraulic pressure that was being supplied to the hydraulic control valve 34 is transferred from the port 35 to the oil passages 42, 43, 44. , connection ports 45, 36, and oil passages 37, 38 to the cylinder chamber 17. When hydraulic pressure is supplied to the cylinder chamber 17, the piston 14 moves to the left in the figure against the spring force of the return compression coil spring 24, and as a result, the buffer compression coil spring 21,
The clutch sleeve 11 together with the connecting sleeve 18 and the radial ball bearing 22 is moved axially to the left in the figure, ie towards the clutch member 8 . By moving the clutch sleeve 11 in the axial direction, the inner teeth 12
The chamfer portion 12a is connected to the internal teeth 7 of the clutch member 8.
When the clutch sleeve 11 collides with the chamfer portion 7a, the clutch sleeve 11 cannot move any further to the left in the figure, but the piston 14 continues to move to the left in the figure by the hydraulic pressure supplied to the cylinder chamber 17. , the piston 14 moves to the other side in the figure with respect to the connecting sleeve 18 while compressing the buffer compression coil spring 21. When the clutch sleeve 11 rebounds due to the collision of the chamfer part 12a of the internal teeth 12 of the clutch sleeve 11 with the chamfer part 7a of the external teeth 7 of the clutch member 8, the axial direction The connecting sleeve 18, which is immovably connected to the piston 14, moves to the right in the figure with respect to the piston 14 while compressing the buffer compression coil spring 21. When the chamfer part 12a of the internal tooth 12 of the clutch sleeve 11 and the chamfer part 7a of the external tooth 7 of the clutch member 8 engage with each other due to the relative rotation between the connecting shaft 2 and the output shaft 3, the compressed buffer is compressed. Due to the spring force of the coil spring 21, the clutch sleeve 11 moves to the left at high speed together with the connection sleeve 18 and the radial ball bearing 22, and the outer teeth 12 and the inner teeth 7
A meshing engagement is performed. When the external teeth 12 and the internal teeth 7 engage with each other, the rotational power of the connecting shaft 2 is transmitted to the clutch sleeve 11 through the meshing portion between the external teeth 7 and the internal teeth 12, and then between the internal teeth 12 and the external teeth. 9, the clutch sleeve 11 transmits the signal to the output shaft 3. That is, four-wheel drive is started.

Even after the transmission of rotational power has started through the clutch sleeve 11 as described above, the clutch sleeve 11 is driven to the left in the figure in order to complete the engagement between the internal teeth 12 and the external teeth 7. The rotational power transmitted from the connection shaft 2 to the output shaft 3 via the clutch sleeve 11 presses the internal teeth 12 and the external teeth 7 against each other, thereby creating the drive necessary to move the clutch sleeve 11 to the left in the figure. Power increases. Therefore, at this time, the piston 14 moves to the left in the figure with respect to the connection sleeve 18 while compressing the buffer compression coil spring 21.
4 and _{the connecting sleeve 18 is smaller than the total stroke S 2 of} the piston 14, so that the piston can move toward the connecting sleeve 18 at its tip end.
comes into direct contact with the flange piece 18a of the connecting sleeve 18 and directly drives the connecting sleeve 18 to the left in the figure.
As a result, the clutch sleeve 11 is driven to the left in the figure together with the radial ball bearing 22, and the clutch sleeve 11 is positioned at the connection position, and the engagement between the internal teeth 12 and the external teeth 7 is completed.

When the hydraulic control valve 34 is switched from the oil supply position to the oil drain position to cancel four-wheel drive, the cylinder chamber 17
is connected to the hydraulic control valve 3 via oil passages 38, 37, connection ports 36, 45, oil passages 44, 43, and port 42.
It is connected to a not-illustrated oil drain port 4, and the hydraulic pressure in the cylinder chamber 17 is drained. When the hydraulic pressure in the cylinder chamber 17 is discharged and the piston 14 moves to the right in the figure by the spring force of the return compression coil spring 24, the connecting sleeve 18 is moved to the right in the figure by the stopper plate 20. As a result, the clutch sleeve 11 moves to the right in the figure together with the radial ball bearing 22.
The inner teeth 12 are spaced apart from the engagement with the outer teeth 7 of the clutch member 8. As a result, the connecting shaft 2 and the rear wheel drive shaft 3 are disconnected, and four-wheel drive is released.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited thereto, and various other embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of the drawing]

The attached figure is a longitudinal sectional view showing one embodiment of a transfer device for a four-wheel drive power transmission device according to the present invention. 1... Extension housing, 2... Connection shaft, 3... Rear wheel drive shaft, 4... Short shaft portion, 5...
Bearing hole, 6... Radial ball bearing, 7... External tooth, 8... Clutch member, 9... External tooth, 10...
Clutch member, 11...Clutch sleeve, 12
...Inner teeth, 13...Cylinder bore, 14...Piston, 15, 16...Oil seal, 17...Cylinder chamber, 18...Clutch sleeve, 19...
Bolt, 20...Stopper plate, 21...Buffer compression coil spring, 22...Radial ball bearing, 23...Spring retainer, 24...Return compression coil spring, 25...Gap, 29...Collar, 30~ 32...Snat spring, 34...Hydraulic control valve, 35...Port, 36...Connection port, 37, 38...Oil passage, 39...Blind plug, 40
...Transmission case, 41...Output shaft, 42-44...Oil passage, 45...Connection port, 46...Blind plug.

Claims (1)

[Claims] 1 A clutch that is incorporated in an extension housing attached to one end of a transmission case and selectively connects the output shaft of a transmission and a wheel drive shaft, and a hydraulic servo device that connects and disconnects the clutch. The hydraulic servo device has a hydraulic chamber defined in a part of the extension housing in cooperation with the extension housing, and the hydraulic servo device includes a hydraulic chamber attached to the one end of the transmission case. A transfer system for a four-wheel drive power transmission device configured such that hydraulic pressure is supplied and discharged from a hydraulic pressure control valve through an oil passage formed in the one end of the transmission case and the extension housing. Device.