JP2022012435A - Power transmission device - Google Patents

Abstract

To provide a power transmission device which is reduced in a cost by simplifying a constituent which is assembled to a drive pinion, and suppressed in rotation imbalance.SOLUTION: A power transmission device 8 comprises: a differential device 50; a drive pinion 60 having a shaft part 61 extending in a vehicle body fore-and-aft direction, and a gear part 62 which is formed at one end of the shaft part 61, and engaged with a ring gear 55 of the differential device 50; a companion flange 70 having a power transmission part 72 which is spline-fit to the shaft part 61; a housing 51; and a unit bearing 52 which rotatably supports the drive pinion 60 to the housing 51, and in which first and second bearings 52a, 52b are integrated. The companion flange 70 has an integrated inner race part 73 extending in an axial direction from the power transmission part 72, and constituting an inner race of the second bearing 52b, and a support part 74 for supporting a different inner race 52d of the first bearing 52a.SELECTED DRAWING: Figure 4

Description

The present invention relates to a vehicle power transmission device.

Generally, a differential device as a power transmission device mounted on a vehicle such as an automobile includes a differential device that absorbs the difference in rotation between the left and right drive wheels, a drive pinion that inputs power from a power source to the differential device, and the like. It includes a housing that houses the differential and drive pinion, a companion flange that transmits rotation from the power source to the drive pinion, and a pair of bearings that rotatably support the drive pinion in the housing.

The pair of bearings are usually provided at axially spaced positions in order to increase the supporting rigidity of the drive pinion. Therefore, the axial dimension of the power transmission device increases, but the power transmission device described in Patent Document 1 has a configuration in which the outer races of the pair of bearings are integrated and separate inner races are arranged adjacent to each other. By adopting the unit bearing, this increase in the axial dimension is suppressed.

Japanese Unexamined Patent Publication No. 2011-179619

However, in general, the cost of the unit bearing tends to increase as compared with the conventional bearing in which the inner race and the outer race are formed separately.

Further, in the above-mentioned power transmission device, it is necessary to assemble a pair of inner races of a pair of bearings and a companion flange to the drive pinion, respectively. Therefore, the number of assembled parts to be assembled to the drive pinion is large, and the rotation imbalance tends to increase due to the deviation of each part with respect to the rotation center of the drive pinion.

Therefore, the present invention provides a power transmission device that reduces costs by simplifying the components assembled to the drive pinion and suppresses rotational imbalance.

The present invention includes a differential device that absorbs the difference in rotation between the left and right drive wheels, a shaft portion that extends in the front-rear direction of the vehicle body, and a gear portion formed at one end of the shaft portion, and also includes a ring gear of the differential device. A cylindrical companion flange equipped with a drive pinion that meshes with the drive pinion, a power transmission unit that is spline-fitted to the shaft portion of the drive pinion, and a power transmission unit that transmits rotation from a power source to the drive pinion, and the differential device. A housing that accommodates the drive pinion, a first bearing that rotatably supports the drive pinion in the housing and is arranged on the gear portion side, and the gear in the axial direction of the first bearing. A unit bearing integrated with a second bearing adjacent to the opposite side of the portion is provided, and the companion flange extends axially from the power transmission portion to form an integrated inner race of the second bearing. Provided is a power transmission device having a race portion and a support portion extending axially further from the integrated inner race portion to support a separate inner race of the first bearing.

According to this configuration, the inner race of the second bearing of the unit bearing is composed of the integrated inner race portion integrally formed with the companion flange, and the separate inner race of the first bearing is continuous with the integrated inner race. Since it is supported by the support portion, the drive pinion is assembled with a companion flange to which a unit bearing is mounted in advance. As a result, the number of parts to be assembled to the drive pinion is reduced, and it is possible to reduce the cost and the assembly man-hours.

For example, when the inner race of the first bearing, the inner race of the second bearing, and the companion flange are assembled to the drive pinion, a deviation of the drive pinion with respect to the rotation center may occur in each component. On the other hand, in the present invention, since the companion flange to which the unit bearing is mounted in advance is attached to the drive pinion, it is possible to suppress an increase in the rotational imbalance caused by the displacement with respect to the drive pinion.

In addition, the power transmission function that transmits the power of the companion flange and the drive pinion support function of the pair of inner races are integrated into the companion flange, so the configuration of the companion flange and the integrated inner race can be simplified, and the unit bearing is used. The increase in cost can be suppressed.

The power transmission portion of the companion flange is formed to have an inner diameter smaller than that of the support portion and the integrated inner race portion, and the drive pinion has a small diameter portion in which the power transmission portion is fitted on the outer peripheral side and the support. The portion and the integrated inner race portion are provided with a large diameter portion to be press-fitted to the outer peripheral side, and the axial dimension from the end portion of the support portion on the gear portion side to the end portion of the power transmission portion on the gear portion side is , The dimension may be shorter than the axial dimension from the end of the large diameter portion on the anti-gear portion side to the end of the small diameter portion on the anti-gear portion side.

According to this configuration, when assembling the companion flange to the drive pinion, the power transmission portion is inserted into the small diameter portion before the support portion of the companion flange is inserted into the large diameter portion. As a result, before the support portion and the integrated inner race portion are press-fitted into the drive pinion, the spline of the power transmission portion can be first applied to the small diameter portion to perform phase matching.

The support portion is continuous with the integrated inner race portion and has an outer diameter set to be smaller than that of the integrated inner race portion. A gap is set between the end face on the gear portion side and the end face.

According to this configuration, the unit bearing can be adjusted to an appropriate preload.

A shim is arranged between the end surface of the separate inner race on the gear portion side and the end surface of the gear portion on the companion flange side.

According to this configuration, the axial position of the drive pinion can be appropriately adjusted by adjusting the thickness of the shim. As a result, the meshing between the gear portion of the drive pinion and the ring gear is properly set.

The power transmission device may be arranged on the power source side of a four-wheel drive vehicle based on a front engine rear drive or a rear engine front drive vehicle.

According to this configuration, the power transmission device of the present invention can be applied more effectively. For example, when applied to a four-wheel drive vehicle based on a vehicle with a front engine and a rear drive engine installed vertically, it is easy to secure a foot space for the passenger seat.

According to the present invention, it is possible to provide a power transmission device in which cost reduction is achieved by simplifying components and rotation imbalance is suppressed.

The schematic block diagram of the vehicle which mounted the power unit device which concerns on embodiment of this invention. A perspective view showing a power transmission device and its surroundings. FIG. 2 is a cross-sectional view of the power transmission device along the line III-III of FIG. Enlarged view of arrow IV in FIG. A cross-sectional view showing a state immediately before assembling a companion flange in which a unit bearing is previously mounted on a drive pinion.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a vehicle equipped with a power transmission device according to an embodiment of the present invention. As shown in FIG. 1, the vehicle 1 equipped with the power transmission device according to the embodiment of the present invention is a front engine / rear drive vehicle-based engine vertical four-wheel drive vehicle. In the vehicle 1, an engine 2 as a power source is arranged in the front portion of the vehicle body, a transmission 3 is arranged behind the vehicle body of the engine 2, and a transfer device 4 is arranged behind the vehicle body of the transmission 3. The engine 2, the transmission 3, and the transfer device 4 are arranged so that their axes extend in the front-rear direction of the vehicle body.

The transfer device 4 transmits the power transmitted from the engine 2 from the transmission 3 to the left and right rear wheels 11L and 11R via the rear wheel propeller shaft 5 extending rearward and the rear wheel differential device 6. It is transmitted to the left and right front wheels 12L and 12R via the front wheel propeller shaft 7 extending forward and the front wheel differential device 8 as a power transmission device.

The differential device 8 is arranged on the left side of the vehicle body of the engine 2. A drive shaft 20 extending to the left side in the vehicle body width direction is connected to the differential device 8, and a drive shaft 30 extending to the right side in the vehicle body width direction is connected to the differential device 8.

The drive shaft 20 includes a differential side shaft 21 connected to the differential device 8, a wheel side shaft 22 connected to the front wheel 12L, and a differential side universal joint 24 and a wheel side universal joint to the differential side shaft 21 and the wheel side shaft 22. It includes an intermediate shaft 23 connected via 25.

The drive shaft 30 includes a differential side shaft 31 connected to the differential device 8, a wheel side shaft 32 connected to the front wheel 12R, and a differential side universal joint 34 and a wheel side universal joint to the differential side shaft 31 and the wheel side shaft 32. It includes an intermediate shaft 33 connected via 35.

In the vehicle 1, the drive shaft 30 extending from the differential device 8 arranged on the left side of the vehicle body of the engine 2 to the right side of the vehicle body is inserted into a through hole provided in the oil pan of the engine 2 to lower the vehicle height. It extends to the right and is connected to the front wheel 12R.

Next, the differential device 8 mounted on the vehicle according to the present embodiment will be described with reference to FIGS. 2 to 4.

The differential device 8 transmits the rotation of the engine 2 to the differential device 50 for absorbing the difference in rotation between the left and right front wheels, the drive pinion 60 that meshes with the ring gear 55 described later in the differential device 50, and the drive pinion 60. A companion flange 70, a housing 51 that houses the differential device 50 and the drive pinion 60, and a unit bearing 52 that integrates a pair of bearings 52a and 52b that rotatably support the drive pinion 60 in the housing 51. .. The housing 51 is fitted to the left side of the vehicle body of the oil pan 40 and attached to the oil pan 40.

The differential device 50 includes a differential case 54 rotatably supported by a housing 51 via a bearing 53, a ring gear 55 fixed to the differential case 54, and a pinion fixed to the differential case 54 and extending in a direction orthogonal to the vehicle body width direction. It has a shaft 57, a pair of pinion gears 58 rotatably fitted to the pinion shaft 57 facing each other, and a pair of left and right side gears 59 that mesh with the pair of pinion gears 58.

Drive shafts 20 and 30 inserted into the shaft insertion portions 51a and 54a provided in the housing 51 and the differential case 54 are spline-fitted to the pair of side gears 59, respectively. The drive shafts 20 and 30 can rotate relative to the housing 51 and the differential case 54 together with the side gear 59.

As described above, the drive shaft 20 on the left side of the vehicle body includes a differential side shaft 21 connected via a differential side universal joint 24 and a wheel side universal joint 25, a wheel side shaft 22, and an intermediate shaft 23. 21 is connected to the differential device 50.

The drive pinion 60 is inserted into the drive pinion insertion portion 51b provided on the rear side of the vehicle body of the housing 51, and is arranged on the right side of the ring gear 55 in the vehicle body width direction. More specifically, the drive pinion 60 has a shaft portion 61 extending in the front-rear direction of the vehicle body and a gear portion 62 formed at the front end of the shaft portion 61, and the ring gear 55 meshes with the gear portion 62 of the drive pinion 60. ing. Lubricating oil is sealed in the housing 51 of the differential device 8, and a sealing member 41 for preventing leakage of the lubricating oil is arranged in each of the insertion portions 51a and 51b of the housing 51. ing.

As described above, the drive pinion 60 is rotatably supported by the housing 51 via a unit bearing 52 in which a pair of bearings 52a and 52b are integrated. A companion flange 70 is spline-fitted to the drive pinion 60. The companion flange 70 is connected to the front wheel propeller shaft 7 via a universal joint 13 so that power from the engine 2 is input. Power from the engine 2 is transmitted to the drive pinion 60 via the companion flange 70.

Next, the configuration of the drive pinion 60, the unit bearing 52, and the companion flange 70 of the differential device 8 will be described with reference to FIGS. 4 and 5.

As described above, the drive pinion 60 includes a shaft portion 61 extending in the front-rear direction of the vehicle body and a gear portion 62 formed at the front end of the shaft portion 61. The shaft portion 61 of the drive pinion 60 is provided on the large diameter portion 61a continuous with the gear portion 62, the small diameter portion 61b extending from the anti-gear portion 62 side of the large diameter portion 61a, and the anti-gear portion 62 side of the small diameter portion 61b. It has a screw portion 61c.

The large-diameter portion 61a is formed with a press-fit fitting portion 61d into which the integrated inner race portion 73 and the support portion 74 of the companion flange 70, which will be described later, are press-fitted, and a spline portion 61e is formed on the outer periphery of the small-diameter portion 61b, which will be described later. The power transmission portion 72 of the companion flange 70 is spline-fitted.

The companion flange 70 includes a flange portion 71 located on the rear side of the vehicle body and connected to the front wheel propeller shaft 7 via a universal joint 13, a cylindrical power transmission portion 72 extending axially from the flange portion 71, and power. A cylindrical integrated inner race portion 73 extending in the axial direction from a portion outside the radial direction of the transmission portion 72, and a support portion 74 continuous with the integrated inner race portion 73 are provided.

On the inner peripheral side of the flange portion, a seat surface 71a on which a locknut B1 for connecting the companion flange 70 and the drive pinion is seated is formed by screwing into the threaded portion 61c of the drive pinion 60.

The power transmission unit 72 has an inner diameter corresponding to the small diameter portion 61b of the drive pinion 60, and a spline portion 72a is formed on the inner peripheral side of the power transmission unit 72. In the power transmission unit 72, the power input to the companion flange 70 is transmitted to the drive pinion 60 by spline fitting the spline portion 72a and the spline portion 61e of the small diameter portion 61b of the drive pinion 60.

The integrated inner race portion 73 and the support portion 74 have an inner diameter larger than that of the power transmission portion 72 and have an inner diameter corresponding to the large diameter portion 61a of the drive pinion 60. A vertical wall portion 72b forming an end surface of the power transmission portion 72 on the gear portion 62 side is formed between the power transmission portion 72 and the integrated inner race portion 73. The integrated inner race portion 73 and the support portion 74 are press-fitted into the large diameter portion 61a of the drive pinion 60.

The support portion 74 is formed to have a smaller outer diameter than the integrated inner race portion 73. A vertical wall portion 73a forming an end surface of the integrated inner race portion 73 on the gear portion 62 side is formed between the outer peripheral surface of the integrated inner race portion 73 and the outer peripheral surface of the support portion 74.

The unit bearing 52 has a first bearing 52a arranged on the front side of the vehicle body (gear portion 62 side) and a second bearing 52b adjacent to the anti-gear portion 62 side of the first bearing 52a. The first and second bearings 52a and 52b are installed between the pair of inner races 52d and 52e provided respectively, the common outer race 52c, and the outer race 52c and the pair of inner races 52d and 52e. It includes ball members 52f and 52g as a pair of rolling elements.

The outer race 52c includes a main body portion 52h extending in the axial direction and a flange portion 52i extending radially outward from the end portion (anti-gear portion 62 side) on the rear side of the vehicle body of the main body portion 52h. The main body portion 52h is arranged inside the insertion portion 51b of the housing 51, and the flange portion 52i is fastened to the flange portion 51c extending radially outward from the end portion on the rear side of the vehicle body of the housing 51 by bolts B2. The outer race 52c is positioned in the axial direction of the housing 51 by the flange portion 52i.

The inner race 52e of the second bearing 52b is composed of an integrated inner race portion 73 of the companion flange 70. The inner race (separate inner race) 52d of the first bearing 52a is press-fitted to the outer periphery of the support portion 74 of the companion flange 70.

A gap G for adjusting the preload of the separate inner race 52d is provided between the end surface of the separate inner race 52d on the anti-gear portion 62 side and the vertical wall portion 73a of the integrated inner race portion 73. The separate inner race 52d is arranged so as to project toward the front side of the vehicle body with respect to the support portion 74.

A ring shape for appropriately adjusting the axial position of the gear portion 62 with respect to the ring gear 55 between the end surface 52j on the gear portion 62 side of the separate inner race 52d and the end surface on the companion flange 70 side of the gear portion 62. Sim 81 is arranged.

The axial dimension L1 from the end of the support portion 74 on the gear portion 62 side to the vertical wall portion 72b of the power transmission portion 72 is from the end of the large diameter portion 61a on the anti-gear portion 62 side to the anti-gear portion of the small diameter portion 61b. It is set shorter than the axial dimension L2 to the end on the 62 side.

Here, with reference to FIG. 5, the assembly of the drive pinion 60 of the differential device 8 of the present embodiment will be described.

A shim 81 is inserted into the gear portion 62 of the drive pinion 60, and then a companion flange 70 to which the unit bearing 52 and the seal member 41 are previously mounted is assembled to the drive pinion. More specifically, the support portion 74 is press-fitted into the large diameter portion 61a of the drive pinion 60, and the power transmission portion 72 is spline-fitted into the small diameter portion 61b.

As described above, the axial dimension L1 from the end of the support portion 74 of the companion flange on the gear portion 62 side to the vertical wall portion 72b of the power transmission portion 72 is the end portion of the large diameter portion 61a on the anti-gear portion 62 side. Since it is set shorter than the axial dimension L2 from the small diameter portion 61b to the end on the anti-gear portion 62 side, the power transmission portion is before the support portion 74 of the companion flange 70 is press-fitted into the large diameter portion 61a. 72 is inserted into the small diameter portion 61b. Therefore, before the support portion 74 and the integrated inner race portion 73 are press-fitted into the drive pinion 60, the spline of the power transmission portion 72 is first applied to the small diameter portion 61b to be phase-aligned.

The companion flange 70 is inserted until the flange portion 52i of the outer race 52c abuts on the flange portion 51c of the housing 51, and the outer race 52c and the housing 51 are coupled by the bolt B2.

The drive pinion 60 and the companion flange 70 are assembled by screwing the locknut B1 into the threaded portion 61c of the drive pinion 60 inserted into the flange portion 71 of the companion flange 70. At this time, the separate inner race 73 abuts on the shim 81, the gap between the integrated inner race 73 and the vertical wall portion 73a is adjusted, and the preload of the separate inner race 52d is appropriately set.

The axial position of the drive pinion 60 can be adjusted by the thickness (axial dimension) of the shim 81. Specifically, the shim 81 can select a plurality of widths (axial dimensions), and appropriately sets the axial dimensions of the drive pinion 60 with respect to the ring gear 55 caused by variations in units and parts. You can do it.

According to the vehicle 1 provided with the differential device 8 according to the present embodiment, the following effects can be obtained.

As described above, the inner race 52e of the second bearing 52b of the unit bearing 52 is composed of the integrated inner race 73 integrally formed with the companion flange 70, and the inner race 52d of the first bearing 52a is integrally inner. Since it is press-fitted into the support portion 74 continuous with the race 73, the drive pinion 60 is assembled with the companion flange 70 to which the unit bearing 52 is mounted in advance. As a result, the number of parts to be assembled to the drive pinion 60 is reduced, and the cost and the assembly man-hours can be reduced.

For example, when the inner race 52d of the first bearing 52a, the inner race 52e of the second bearing 52b, and the companion flange 70 are assembled to the drive pinion 60, each component is displaced with respect to the rotation center R of the drive pinion 60. There is a risk. On the other hand, in the present invention, since the companion flange 70 to which the unit bearing 52 is mounted in advance is attached to the drive pinion 60, the deviation of the drive pinion 60 with respect to the rotation center can be reduced. As a result, it is possible to suppress an increase in the rotational imbalance caused by the deviation of each component with respect to the drive pinion 60.

Further, since the power transmission function for transmitting the power from the engine 2 of the companion flange 70 and the drive pinion support function of the pair of inner races 52d and 52e are integrated into the companion flange 70, the companion flange 70 and the integrated inner The configuration of the race 73 can be simplified, and the cost increase due to the unit bearing 52 can be suppressed.

Further, as described above, the axial dimension L1 from the end portion of the support portion 74 on the gear portion 62 side to the vertical wall portion 72b of the power transmission portion 72 is from the end portion of the large diameter portion 61a on the anti-gear portion 62 side. It is set shorter than the axial dimension L2 to the end of the small diameter portion 61b on the anti-gear portion 62 side.

In other words, when assembling the companion flange 70 to the drive pinion 60, as shown in FIG. 5, the power transmission portion 72 has a small diameter portion before the support portion 74 of the companion flange 70 is press-fitted into the large diameter portion 61a. It is inserted in 61b. Therefore, before the support portion 74 and the integrated inner race portion 73 are press-fitted into the drive pinion 60, the spline of the power transmission portion 72 can be first applied to the small diameter portion 61b to perform phase matching.

According to this, the companion flange 70 to which the integrated inner race portion 73 and the support portion 74 are integrally provided and the unit bearing 52 is mounted in advance can be assembled to the drive pinion 60.

Further, as described above, since a gap G is set between the end surface of the separate inner race 52d on the anti-gear portion 62 side and the vertical wall portion 73a of the integrated inner race portion 73, the second bearing 52b Can be adjusted to the appropriate preload.

Further, as described above, since the shim 81 is arranged between the end surface of the separate inner race 52d on the gear portion 62 side and the end surface of the gear portion 62 on the flange portion 71 side, the thickness of the shim 81 is increased. By preparing, the axial position of the drive pinion can be adjusted appropriately. As a result, the meshing between the gear portion 62 of the drive pinion 60 and the ring gear 55 is properly set.

As described above, since the differential device 8 has a configuration in which the drive pinion 60 is supported by the housing 51 by the unit bearing 52, when the first bearing 52a and the second bearing 52b are separately configured. In comparison, the axial dimensions are shortened. As a result, when the differential device 8 according to the present invention is mounted, it is arranged on the engine 2 side in a four-wheel drive vehicle based on a vehicle with a front engine and a rear drive, so that it is easy to secure a foot space for the passenger seat.

The present invention is not limited to the embodiments exemplified, and various improvements and design changes can be made without departing from the gist of the present invention.

The power transmission device according to the embodiment of the present invention has been described as being applied to a four-wheel drive vehicle having a vertical engine based on a front engine / rear drive vehicle, but the present invention is not limited to this, and the front engine is not limited to this. -It may be applied to a front-drive vehicle-based engine horizontal four-wheel drive vehicle or the like, or it may be applied to a rear differential of a front-engine / rear-drive two-wheel drive vehicle.

As described above, according to the present invention, it is possible to provide a power transmission device in which the cost is reduced by simplifying the components assembled to the drive pinion and the rotational imbalance is suppressed. It may be suitably used in the field of manufacturing technology of a vehicle or a vehicle on which it is mounted.

1 Vehicle 2 Engine (power source)
8 Differential device (power transmission device)
50 Differential device 51 Housing 52 Unit bearing 52a 1st bearing 52b 2nd bearing 52d Separate inner race 55 Ring gear 60 Drive pinion 61 Shaft 61a Large diameter 61b Small diameter 62 Gear 70 Companion flange 72 Power transmission 73 Integrated inner Race part 74 Support part 81 Sim G Gap L1 Axial dimension L2 Axial dimension

Claims (5)

A differential device that absorbs the difference in rotation between the left and right drive wheels,
A drive pinion that includes a shaft portion that extends in the front-rear direction of the vehicle body and a gear portion formed at one end of the shaft portion, and that meshes with the ring gear of the differential device.
A cylindrical companion flange spline-fitted to the shaft portion of the drive pinion and provided with a power transmission portion that transmits rotation from a power source to the drive pinion.
A housing that houses the differential and the drive pinion,
The drive pinion is rotatably supported by the housing, and a first bearing arranged on the gear portion side and a second bearing adjacent to the side opposite to the gear portion in the axial direction of the first bearing are provided. With integrated unit bearings
Equipped with
The companion flange is
An integral inner race portion extending in the axial direction from the power transmission portion to form an inner race of the second bearing, and an integrated inner race portion.
A support portion extending in the axial direction from the integrated inner race portion to support the separate inner race of the first bearing, and a support portion.
Power transmission device with. The power transmission portion of the companion flange is formed to have an inner diameter smaller than that of the support portion and the integrated inner race portion.
The drive pinion includes a small diameter portion in which the power transmission portion is fitted to the outer peripheral side, and a large diameter portion in which the support portion and the integrated inner race portion are press-fitted to the outer peripheral side.
The axial dimension from the end of the support portion on the gear portion side to the end of the power transmission portion on the gear portion side is from the end portion of the large diameter portion on the anti-gear portion side to the anti-gear portion side of the small diameter portion. The power transmission device according to claim 1, which is set shorter than the axial dimension to the end of the. The support portion is continuous with the integrated inner race portion and has an outer diameter smaller than that of the integrated inner race portion.
The power transmission device according to claim 1 or 2, wherein a gap is set between the end surface on the anti-gear portion side of the separate inner race portion and the end surface on the gear portion side of the integrated inner race portion. The power transmission according to any one of claims 1 to 3, wherein a shim is arranged between the end surface of the separate inner race on the gear portion side and the end surface of the gear portion on the companion flange side. Device. The power transmission device according to any one of claims 1 to 4, wherein the power transmission device is arranged on the power source side in a four-wheel drive vehicle based on a front engine rear drive or a rear engine front drive vehicle. Power transmission device.

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