JP2007187272A - Automatic belt tension adjuster for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of components of an auto tensioner while keeping high vibration and impact shock damping function by the cooperation of a hydraulic damper mechanism and a spring, to reduce an installation space of the auto tensioner so that it can be easily installed in a narrow part, and to increase supporting rigidity of the auto tensioner. <P>SOLUTION: In an automatic belt tension adjuster for an engine, the auto tensioner is constituted by integrally constituting a tension pulley supporting housing supporting a tension pulley and a damper case of the hydraulic damper mechanism, providing an engine-side housing with a cylindrical portion concentric to the hydraulic damper mechanism, the damper case is fitted to an inner peripheral side of the cylindrical portion relatively movably in the shaft center direction, a spring hung between the tension pulley supporting housing and the engine-side housing is disposed at an outer peripheral side of the cylindrical portion, and the cylindrical portion of the engine-side housing and the damper case are constantly fitted in the whole stroke of the auto tensioner. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention automatically adjusts the position of a tension pulley by an auto tensioner that includes a dashpot type hydraulic damper mechanism and a spring that cooperates with the hydraulic damper mechanism, so that the tension pulley and the plurality of pulleys can be adjusted. The present invention relates to an automatic belt tension adjusting device for an engine for maintaining the tension of a belt installed on the belt at a required tension.

  An automatic belt tension adjusting device mainly used in a vehicle engine has two oil chambers defined by a damper piston fitted in a damper case so as to be relatively slidable through a small passage formed in the damper piston. It is installed between the tension pulley and a plurality of pulleys by automatically adjusting the position of the tension pulley by an auto tensioner having a dashpot type hydraulic damper mechanism and a spring that cooperates with the hydraulic damper mechanism. In many cases, the belt is configured to keep the tension of the belt at a required tension.

  FIG. 3 is a schematic front view showing the arrangement of an auxiliary machine driving pulley and a belt tension automatic adjusting device at the front end portion of a vehicle engine equipped with such a belt tension automatic adjusting device with an auto tensioner, and FIG. 4 is a schematic side view. FIG. 3 is a view (indicated by an arrow Z in FIG. 3). In FIGS. 3 to 4, 14 is an engine body, 10 is a crank pulley (10z is a crank shaft center) fixed to a shaft end of a crank shaft (not shown), 11 Is a water pump pulley for driving a water pump, 12 is an air conditioner pulley for driving a compressor of an air conditioner, and 13 is an alternator pulley for driving an alternator.

  1 is a tension pulley, and a belt 2 is installed between the tension pulley 1 and the crank pulley 10, the water pump pulley 11, the air conditioner pulley 12, and the alternator pulley 13, and these pulleys are connected to the crank pulley 10. The engine 2 is linked via the belt 2 by the input engine rotational force. An automatic tensioner 24 automatically adjusts the tension of the belt 2 by changing the position of the tension pulley 1, and a spring fixing device 26 for fixing the spring 25 of the automatic tensioner 24 in a contracted state when the belt 2 is replaced. It is.

For such an autotensioner 24, techniques such as Patent Document 1 (Japanese Patent Laid-Open No. 10-299846) and Patent Document 2 (Japanese Patent Laid-Open No. 2000-213607) are provided.
In Patent Document 1, an actuator 6 having an arm 1 that is swingably attached to an engine block 4 and that has a tension pulley 5 rotatably attached to an end of the swing side, and that has a hydraulic damper mechanism 11 on the arm 1. The rod 10 is connected, and the tension pulley 5 is pressed against the belt by pressing the arm 1 in one direction by the elastic force of the tension adjusting spring 12 which gives the rod 10 the outward projecting property. A hydraulic auto tensioner that automatically adjusts is disclosed.

  In Patent Document 2, a damping spring is arranged concentrically on the inner periphery of a cylindrical portion of a tension pulley support housing that rotatably supports the tension pulley, and one end of the spring is supported by the tension pulley support housing. The outer periphery of the spring is fixed to the engine body and is covered with a cylindrical portion on the engine side housing side that is concentric with the cylindrical portion of the tension pulley support housing, and the other end side of the spring is supported on the engine side housing side. An automatic belt tension adjusting device is disclosed.

Japanese Patent Laid-Open No. 10-299846 JP 2000-213607 A

However, the prior art has the following problems.
In the hydraulic auto tensioner shown in Patent Document 1, since the arm 1 for transmitting the elastic force of the agitator 6 and the tension adjusting spring 12 to the tension pulley 5 is provided, the installation space becomes large, and many It becomes difficult to install in the front part of the engine where the accessory drive pulley is disposed.

  Further, since the outer periphery of the cylinder 8 that accommodates the hydraulic damper mechanism 11 and the outer cylinder that is provided around the cylinder 8 in cooperation with the rod 10 are provided at a distance from each other, it is generated due to belt runout or the like. There is a possibility that the outer peripheral surface of the cylinder 8 and the inner peripheral surface of the outer cylinder collide with the lateral vibration of the tension pulley 5 to cause wear on the outer peripheral surface.

  Further, in the belt tension automatic adjusting device disclosed in Patent Document 2, a damping spring is disposed concentrically on the inner periphery of the cylindrical portion of the tension pulley support housing, and the outer periphery of the spring is fixed to the engine body. Since the belt tension automatic adjustment device is small and compact, the installation space is relatively small, and the support tension of the auto tensioner can be kept high. The reduction mechanism is not equipped with a hydraulic damper mechanism and is only a spring, and the vibration damping effect of the auto tensioner is reduced.

  Furthermore, in the prior art shown in FIGS. 3 to 4, in addition to the above-described problems, a spring 25 of the auto tensioner 24 is used to relax the tension of the belt 2 when the belt 2 is replaced. As shown by a two-dot chain line in the figure, it is necessary to provide a spring fixing device 26 for holding in a contracted state, so that the structure of the belt tension automatic adjusting device is complicated and the number of parts increases.

  Therefore, in view of the problems of the prior art, the present invention reduces the number of parts of the auto tensioner and reduces the installation space of the auto tensioner while maintaining the high vibration and impact damping function by the cooperation of the hydraulic damper mechanism and the spring. An object of the present invention is to provide an automatic belt tension adjusting device that can be easily installed even in a narrow and narrow part and can increase the support rigidity of an auto tensioner.

  The present invention achieves such an object, and includes a hydraulic damper mechanism having two oil chambers defined by a damper piston that is slidably fitted in a damper case, and a spring that cooperates with the hydraulic damper mechanism. In an automatic belt tension adjusting device for an engine that maintains the tension of a belt laid between the tension pulley and a plurality of pulleys at a required tension by automatically adjusting the position of the tension pulley with an auto tensioner having The auto tensioner is configured integrally with a tension pulley support housing that rotatably supports the tension pulley and a damper case of the hydraulic damper mechanism, and is concentric with the hydraulic damper mechanism in an engine side housing fixed to the engine body. Is formed on the inner peripheral side of the cylindrical portion. A case is fitted so as to be relatively movable in the axial direction of the hydraulic damper mechanism, and the spring provided between the tension pulley support housing and the engine side housing is disposed on the outer peripheral side of the cylindrical portion, and the engine The cylindrical portion of the side housing and the damper case are always fitted in the entire stroke of the auto tensioner (Claim 1).

According to this invention, a tension pulley support housing is provided while maintaining a high vibration and shock damping function by cooperating with the dashpot effect of the hydraulic damper mechanism and the spring characteristics of the spring by providing the hydraulic damper mechanism and the spring together. And the damper case of the hydraulic damper mechanism are integrally formed, and the damper case is concentrically fitted to the inner peripheral side of the cylindrical part formed in the engine-side housing so as to be relatively movable, and the outer peripheral side of the cylindrical part By arranging the springs concentrically, means for connecting the engine side member and the tension pulley side member as in the prior art becomes unnecessary, and the spring, the cylindrical portion of the engine side housing, the damper case and the damper piston are concentric. With a small and compact structure and a small number of parts It is possible to obtain an automatic belt tensioning device.
The tension pulley support housing and the damper case of the hydraulic damper mechanism are integrally configured, and the damper case is concentrically fitted to the inner peripheral side of the cylindrical portion formed in the engine side housing so as to be relatively movable. Therefore, it is possible to increase the support rigidity on the side of the tension pulley that moves due to fluctuations in belt tension.

  This reduces the installation space for the belt tension automatic adjustment device compared to the conventional technology while maintaining the high vibration and impact damping functions due to the dashpot effect of the hydraulic damper mechanism and the spring characteristics of the spring as described above. Even if the front part of the engine is narrow with many auxiliary machine drive pulleys installed, the belt tension automatic adjustment device can be easily installed, and the number of parts is reduced, and the belt tension changes. The support rigidity on the tension pulley side can be increased.

  In addition, since the cylindrical portion of the engine-side housing and the damper case are always fitted in the entire stroke of the auto tensioner, lateral vibration of the tension pulley due to belt runout or the like is caused through the damper case and the cylindrical portion. The hydraulic damper mechanism can be supported by the engine body, and the hydraulic damper mechanism can be easily assembled without being detached from the engine-side housing when the hydraulic damper mechanism is assembled.

In this invention, specifically, the following configuration is preferable.
(1) One end of the damper piston is fixed to the engine-side housing (claim 2).
Preferably, the engine-side housing is provided with a detent member that contacts the damper piston and prevents the damper piston from rotating.
With this configuration, the piston rod that constitutes one end of the damper piston is fixed to the engine side housing with a bolt or the like, and the damper piston is prevented from rotating by the non-rotating member. By firmly supporting the housing and fitting with the damper case, the damper piston can be easily assembled into the damper case.

(2) A bush is interposed between the inner peripheral surface of the cylindrical portion of the engine-side housing and the outer peripheral surface of the damper case.
According to this structure, the lateral vibration of the tension pulley accompanying the vibration of the belt due to the belt tension imbalance or the like is received by the bush, and then supported by the engine body through the cylindrical portion of the engine-side housing. Can be reliably suppressed.

(3) An axial position adjusting bolt that adjusts an axial relative position between the engine side housing and the tension pulley support housing is provided between the engine side housing and the tension pulley support housing rather than the spring. It arrange | positions in a front position (Claim 5).
With this configuration, since the axial position adjustment bolt provided between the engine side housing and the tension pulley support housing is disposed at the vehicle front position with respect to the spring, the conventional technique shown in FIGS. In addition, there is no need to provide a separate spring fixing means such as a spring fixing device 26 for fixing the spring 25 of the auto tensioner when the belt 2 is replaced, and the structure of the belt replacing means is simplified and the shaft The assembly work of the auto tensioner performed by pushing and shrinking the spring by the directional position adjusting bolt can be easily performed without being obstructed by the auto tensioner constituting member.

  According to the present invention, the tension pulley support housing and the damper case of the hydraulic damper mechanism are integrally configured while maintaining high vibration and shock damping functions due to the dashpot effect of the hydraulic damper mechanism and the spring characteristics of the spring. In addition, a damper case is concentrically fitted to the inner peripheral side of the cylindrical portion of the engine-side housing, and a spring is concentrically disposed on the outer peripheral side of the cylindrical portion, whereby the spring, the cylindrical portion of the engine-side housing, the damper A belt tension automatic adjustment device with a compact and compact structure in which the case and damper piston are concentrically arranged can be obtained, and the installation space for the belt tension automatic adjustment device can be reduced compared to the prior art, and many auxiliary machines Even if the front part of the engine is narrow with a drive pulley installed, the belt tension itself With an adjusting device can be easily installed, the number of parts can be reduced, further, increases the support rigidity of the tension pulley side moved by fluctuations in belt tension.

  Further, since the cylindrical portion of the engine-side housing and the damper case are always fitted in the entire stroke of the auto tensioner, the lateral vibration of the tension pulley can be supported by the engine body via the damper case and the cylindrical portion, When the hydraulic damper mechanism is assembled, the hydraulic damper mechanism is not detached from the engine-side housing, and the assembly of the hydraulic damper mechanism can be facilitated.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 1 is a front view of an automatic belt tension adjusting device for a vehicle engine according to an embodiment of the present invention as viewed from the front of the engine, and FIG. 2 is a cross-sectional view taken along line AA of FIG.
1 and 2, 100 is an auto tensioner, 1 is a tension pulley, 12 is an air conditioner pulley for driving a compressor of an air conditioner, the tension pulley 1 and the air conditioner pulley 12, the crank pulley 10 and the water pump pulley 11 shown in FIG. , And an alternator pulley 13, a belt 2 is erected, and these supplementary drive pulleys are linked via the belt 2 by the engine rotational force input from the crank pulley 10.

Reference numeral 100 denotes an auto tensioner that automatically adjusts the tension of the belt 2 by changing the position of the tension pulley 1, and is configured as follows.
Reference numeral 3 denotes a tension pulley side housing, and the tension pulley 1 is rotatably supported by the tension pulley side housing 3 via two bearings 34a and 34b.
Reference numeral 40 denotes a damper case in which a hydraulic damper mechanism 101 to be described later is housed. The tension pulley side housing 3 and the damper case 40 are constituted by an integrally cast product (which may be a welded structure product or a resin molded product).
The damper case 40 is erected in a cylindrical shape at the upper part of the tension pulley side housing 3, and a hydraulic damper mechanism 101 to be described later is accommodated therein.

An engine side housing 4 is fixed to the engine body 14 by a plurality of bolts 37. A cylindrical portion 4a concentric with the damper case 40 projects from the lower portion of the engine-side housing 4, and the cylindrical portion 4a and the damper case 40 are arranged in the axial direction of the hydraulic damper mechanism 101 via a bush 6 described later. Are fitted to be movable relative to each other.
The cylindrical portion 4a of the engine-side housing 4 and the damper case 40 are set to have both lengths so that they are always fitted over the entire stroke of the auto tensioner 100.
In this way, the cylindrical portion 4a of the engine side housing 4 and the damper case 40 are always fitted over the entire stroke of the auto tensioner 100, so that the lateral vibration of the tension pulley 1 due to the vibration of the belt 2 or the like is prevented. The hydraulic damper mechanism 101 can be supported by the engine body 14 via the cylinder 40 and the cylindrical portion 4a, and the hydraulic damper mechanism 101 is not detached from the engine-side housing 4 when the hydraulic damper mechanism 101 is assembled, so that the assembly of the hydraulic damper mechanism 101 can be facilitated.
Further, as described above, the engine side housing 4 is fixed to the engine body 14 by a plurality of (three in the present embodiment) bolts 37, so that the force and inclination acting in the lateral direction of the auto tensioner 100 are not affected. Even if the lateral vibration or inclination of the tension pulley 1 due to the vibration of the belt 2 is transmitted from the damper case 40, the engine-side housing 4 will not be displaced or inclined.

A spring 5 is installed between a lower portion of the engine side housing 4 and a base portion of the damper case 40, and is concentric with the cylindrical portion 4 a and the damper case 40 on the outer peripheral side of the cylindrical portion 4 a of the engine side housing 4. (5z is provided on these axes).
A dustproof bellows 39 is installed between the lower portion of the cylindrical portion 4a of the engine-side housing 4 and the base portion of the damper case 40.

A bush 6 is interposed between the inner peripheral surface of the cylindrical portion 4 a of the engine side housing 4 and the outer peripheral surface of the damper case 40. Even if the bush 6 has an outer peripheral surface fixed to the inner peripheral surface of the cylindrical portion 4 a and the inner peripheral surface is slidably fitted to the outer peripheral surface of the damper case 40, the inner peripheral surface is the outer periphery of the damper case 40. The outer peripheral surface may be fitted to the inner peripheral surface of the cylindrical portion 4a so as to be relatively slidable.
As described above, since the bush 6 is interposed between the inner peripheral surface of the cylindrical portion 4a of the engine-side housing 4 and the outer peripheral surface of the damper case 40, the belt 2 is shaken due to belt tension imbalance or the like. The lateral vibration of the tension pulley 1 is received by the bush 6 and then supported by the engine body 14 through the cylindrical portion 4a of the engine side housing 4, whereby the lateral vibration can be reliably suppressed.

In the hydraulic damper mechanism 101, reference numeral 7 denotes a damper piston that is slidably fitted in the damper case 40, and the damper case 40 is partitioned into two oil chambers 9 a and 9 b by the damper piston 7. . The two oil chambers 9a and 9b are communicated with each other by a small-diameter oil passage 8 formed in the damper piston 7. A piston rod 35 is connected to the upper side of the damper piston 7, and the upper end of the piston rod 35 is fastened and fixed to the engine-side housing 4 by a nut 35b. Reference numeral 41 denotes a sleeve which is fixed to a lower portion of the damper piston 7 on the inner periphery of the damper case 40 and restricts the downward movement of the damper piston 7. 4b is an intake / exhaust hole, and the damper case 40
The air in and out of the cylindrical portion 4a is slid.
30 is an oil seal for fluidly supporting the outer periphery of the piston rod 35, 31 is a retainer with a check valve fixed to the lower part of the damper piston 7, and 32 is between the retainer 31 and the bottom of the sleeve 41. This is a return spring installed.

Reference numeral 36 denotes a detent member screwed into the engine-side housing 4, and a tip end surface thereof abuts against a flat portion 35 a formed on the piston rod 35 fastened and fixed to the engine-side housing 4, so that the damper piston 7 It is designed to stop the rotation.
As described above, the piston rod 35 of the damper piston 7 is fixed to the engine-side housing 4 and the anti-rotation member 36 for stopping the rotation of the damper piston 7 is provided, so that the damper piston 7 is firmly attached to the engine-side housing 4. By supporting and fitting with the damper case 40, the damper piston 7 can be easily assembled into the damper case 40.

Reference numeral 33 denotes an axial position adjusting bolt for use in replacing the belt 2 disposed between the engine side housing 4 and the upper surface of the tension pulley side housing 3. The axial position adjusting bolt 33 is disposed at a position in front of the vehicle with respect to the spring 5, and a lower end portion is screwed into a screw portion 33 a formed on the upper surface of the tension pulley side housing 3. By increasing, the spring load of the spring 5 is increased. That is, the tension applied to the belt 2 is relaxed.
If comprised in this way, since the axial position adjustment volt | bolt 33 provided between the engine side housing 4 and the said tension pulley side housing 3 was arrange | positioned in the vehicle forward position rather than the spring 5, it shows to FIGS. Unlike the prior art, there is no need to separately provide a spring fixing means such as a spring fixing device for fixing the spring of the auto tensioner 100 when the belt 2 is replaced, and the structure of the belt 2 replacement means is simplified. At the same time, since the axial position adjusting bolt 33 is arranged at the front position of the vehicle, the replacement work of the belt 2 performed by pressing and contracting the spring 5 can be easily performed without being obstructed by the components of the auto tensioner 100. The axial position adjusting bolt 33 is removed except when the belt 2 is exchanged.

In the belt tension automatic adjusting apparatus configured as described above, the tension of the belt 2 is automatically adjusted by the cooperation of the spring force of the spring 5 and the displacement of the damper piston 7 of the hydraulic damper mechanism 101.
When the tension pulley 1 is vibrated, the oil in the two oil chambers 9a and 9b is perforated in the damper piston 7 by the relative movement of the damper piston 7 and the damper case 40 of the hydraulic damper mechanism 101. The vibration is damped by the so-called dashpot action by entering and exiting through the spring, and the vibration is damped by the elasticity of the spring 5.
14a is a stopper that can contact the lower surface 40a of the damper case 40. The stopper 14a is provided on the engine body 14 to prevent the tension pulley side housing 3 from falling out of the engine side housing 4 due to some cause. ing.

According to this embodiment, by providing the hydraulic damper mechanism 101 and the spring 5 together, high vibration and impact damping functions are maintained by the cooperation of the dashpot effect of the hydraulic damper mechanism 101 and the spring characteristics of the spring 5. The tension pulley side housing 3 and the damper case 40 of the hydraulic damper mechanism 101 are integrally configured, and the damper case 40 is concentrically and relatively movable on the inner peripheral side of the cylindrical portion 4a formed in the engine side housing 4. Further, by disposing the spring 5 concentrically on the outer peripheral side of the cylindrical portion 4a, the means for connecting the engine side member and the tension pulley side member as in the prior art becomes unnecessary, and the spring 5, The cylindrical portion 4a of the engine side housing 4, the damper case 40 and the damper piston 7 are concentric. Equipped with location miniature compact structure can be obtained with less belt tension automatic adjuster of parts.
Further, the tension pulley side housing 3 and the damper case 40 of the hydraulic damper mechanism 101 are integrally formed, and the damper case 40 is concentrically and relatively moved on the inner peripheral side of the cylindrical portion 4a formed in the engine side housing 14. Since the fitting structure is possible, the support rigidity on the side of the tension pulley 1 that moves due to fluctuations in belt tension can be increased.

As a result, the installation space for the automatic belt tension adjusting device is maintained as compared with the prior art while maintaining the high vibration and impact damping function due to the dashpot effect of the hydraulic damper mechanism 101 and the spring characteristics of the spring 5 as described above. Even if the front part of the engine is narrow with many accessory drive pulleys installed, the belt tension automatic adjustment device can be easily installed, and the number of parts is reduced and the belt tension varies. Therefore, the support rigidity on the side of the tension pulley that moves can be increased.
In this embodiment, the tension pulley side housing 3 and the damper case 40 are integrally formed, and the engine side housing 4 is provided outside the damper case 40. However, the engine side housing 4 and the damper case 40 The tension pulley side housing 3 may be provided outside the damper case 40.

  According to the present invention, the number of parts of the auto tensioner is small and the installation space of the auto tensioner can be reduced while maintaining a high vibration and impact damping function due to the cooperation of the hydraulic damper mechanism and the spring. However, it is possible to provide an automatic belt tension adjusting device that can be easily installed and can increase the support rigidity of the auto tensioner.

It is the front view seen from the engine front which shows the belt tension automatic adjustment device of the engine for vehicles concerning the example of the present invention. It is the sectional view on the AA line of FIG. 1 in the said Example. It is the schematic front view seen from the engine front which shows arrangement | positioning of the auxiliary machine drive pulley and belt tension automatic adjustment apparatus in the front-end part of the engine for vehicles provided with the conventional belt tension automatic adjustment apparatus with an auto tensioner. It is a Z arrow line view in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tension pulley 2 Belt 3 Tension pulley side housing 4 Engine side housing 4a Cylindrical part 5 Spring 6 Bush 7 Damper piston 8 Oil passage 9a, 9b Oil chamber 14 Engine main body 33 Axial position adjustment bolt 35 Piston rod 36 Non-rotating member 40 Damper Case 100 Auto tensioner 101 Hydraulic damper mechanism

Claims (5)

  The position of the tension pulley by an auto tensioner comprising a hydraulic damper mechanism having two oil chambers defined by a damper piston fitted in a damper case so as to be slidable relative to each other and a spring cooperating with the hydraulic damper mechanism. The automatic tensioner rotates the tension pulley in an automatic belt tension adjusting device for an engine that maintains the tension of the belt installed between the tension pulley and the plurality of pulleys at a required tension by automatically adjusting the tension pulley. A tension pulley support housing that supports freely and a damper case of the hydraulic damper mechanism are integrally formed, and a cylindrical portion concentric with the hydraulic damper mechanism is formed in an engine-side housing fixed to the engine body. The damper case is placed on the inner circumference side of the hydraulic damper mechanism. And the spring arranged between the tension pulley support housing and the engine side housing is disposed on the outer peripheral side of the cylindrical part, and the cylindrical part of the engine side housing and the damper case Is an automatic belt tension adjusting device for an engine which is always fitted in the entire stroke of the auto tensioner.   The automatic belt tension adjusting device for an engine according to claim 1, wherein one end of the damper piston is fixed to the engine-side housing.   The automatic belt tension adjusting device for an engine according to claim 2, wherein a non-rotating member for stopping rotation of the damper piston is attached to the engine side housing so as to abut against the damper piston.   2. The engine belt tension automatic adjusting device according to claim 1, wherein a bush is interposed between an inner peripheral surface of the cylindrical portion of the engine-side housing and an outer peripheral surface of the damper case.   An axial position adjusting bolt for adjusting an axial relative position between the engine side housing and the tension pulley support housing is disposed between the engine side housing and the tension pulley support housing at a position ahead of the vehicle with respect to the spring. 2. An automatic belt tension adjusting device for an engine according to claim 1, wherein the automatic belt tension adjusting device is arranged.

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