CN212838126U - Air intake system and car of engine - Google Patents

Abstract

The utility model provides an air intake system and car of engine belongs to engine technical field. Comprises a bleed air pipe, an air filter, an air inlet pipe and at least two Helmholtz silencers with different resonance frequencies. Wherein, the one end of bleed pipe and the access connection of air cleaner, the export of air cleaner is connected with the one end of intake pipe, and two at least helmholtz silencers are connected with two at least in the lateral wall of bleed pipe, air cleaner and the lateral wall of intake pipe respectively. To the produced low frequency impulse noise among the air intake system, the different helmholtz silencers of two at least resonant frequency can carry out effective amortization to the sound wave of two at least different frequencies in the low frequency impulse noise respectively to improve air intake system's noise cancelling effect.

Description

Air intake system and car of engine

Technical Field

The disclosure relates to the technical field of engines, in particular to an air intake system of an engine and an automobile.

Background

The main function of the air intake system is to convey clean, dry, sufficient and stable air for the engine to meet the requirement of the engine, and to avoid the abnormal abrasion of the engine caused by the impurities and large-particle dust in the air entering the combustion chamber of the engine. The intake noise of the intake system is one of the main noise sources of the automobile engine, and along with the increase of the rotating speed of the engine and the increase of the intake air flow rate, the turbulence, the vortex intensity of an air flow channel and the pulsation intensity and frequency of the pressure in a pipeline can be increased, so that the intake noise is increased.

In the related art, a helmholtz silencer is usually disposed in a bleed air pipe or an intake pipe of the air intake system to muffle intake noise of the air intake system. However, this type of silencing has a poor silencing effect.

SUMMERY OF THE UTILITY MODEL

The embodiment of the disclosure provides an air intake system of an engine and an automobile, which can improve the silencing effect of the air intake system. The technical scheme is as follows:

in a first aspect, an embodiment of the present disclosure provides an intake system of an engine, including:

a bleed air pipe, an air filter, an air inlet pipe and at least two Helmholtz silencers with different resonance frequencies,

one end of the bleed air pipe is connected with an inlet of the air filter, an outlet of the air filter is connected with one end of the air inlet pipe, and the at least two Helmholtz silencers are respectively connected with at least two of the side wall of the bleed air pipe, the air filter and the side wall of the air inlet pipe.

Optionally, the air intake system of the engine includes a first helmholtz silencer, a second helmholtz silencer, and a third helmholtz silencer, the first helmholtz silencer includes a first connection pipe and a first resonant cavity, the first resonant cavity is connected to the sidewall of the air intake pipe through the first connection pipe, the second helmholtz silencer includes a second connection pipe and a second resonant cavity, the second resonant cavity is connected to the air cleaner through the second connection pipe, the third helmholtz silencer includes a third connection pipe and a third resonant cavity, and the third resonant cavity is connected to the sidewall of the bleed air pipe through the third connection pipe.

Optionally, a size relationship between the first connecting pipe and the first resonant cavity, a size relationship between the second connecting pipe and the second resonant cavity, and a size relationship between the third connecting pipe and the third resonant cavity all satisfy the following formulas:

f＝(C/2pi)*[S/(L*V)]^1/2；

wherein C is a propagation velocity of sound in air, Pi is a circumferential ratio Pi, L is a length of the first connecting pipe, the second connecting pipe or the third connecting pipe, S is a sectional area of the first connecting pipe, the second connecting pipe or the third connecting pipe, and S ranges from 100 Pi to 225 Pi mm²V is a volume of the first resonant cavity, the second resonant cavity, or the third resonant cavity, f is a resonant frequency, one of the first, second, and third helmholtz silencers has a resonant frequency of 80HZ, and the other of the first, second, and third helmholtz silencers has a resonant frequency of 89 HZ.

Optionally, the air cleaner includes cavity and filter screen, the filter screen will the cavity is separated and is close to the first inner chamber of bleed pipe and is close to the second inner chamber of intake pipe, the second resonant cavity pass through the second connecting pipe with the second inner chamber intercommunication.

Optionally, the filter screen is a non-woven soundproof cotton filter screen.

Optionally, the first helmholtz silencer is connected to a side wall of the inlet pipe by a spring clip.

Optionally, the air intake system further comprises 1/4 wave tube, and the 1/4 wave tube is connected with the side wall of the air intake pipe

Optionally, the intake system further includes an intake control valve connected to the intake pipe.

Optionally, a part of the pipe body of the air inlet pipe is a hose.

In a second aspect, embodiments of the present disclosure further provide an automobile including an intake system as described in the first aspect.

The beneficial effects brought by the technical scheme provided by the embodiment of the disclosure at least comprise:

through setting up two at least different helmholtz silencers 4 of resonant frequency, can carry out effective amortization to the sound wave of the low frequency noise of two at least different frequencies in the low frequency impulse noise to improve air intake system's noise cancelling effect.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an air intake system provided by an embodiment of the present disclosure;

FIG. 2 is a schematic diagram illustrating an operational configuration of an air induction system provided by an embodiment of the present disclosure;

FIG. 3 is a graphical illustration of the noise level of an engine provided by an embodiment of the present disclosure;

FIG. 4 is a schematic structural view of a Helmholtz silencer coupled to an air cleaner according to an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of a Helmholtz silencer coupled to an intake pipe according to an embodiment of the present disclosure;

fig. 6 is a partial schematic structural view of an air cleaner according to an embodiment of the present disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In the related art, what is commonly referred to as intake noise is not noise generated by the intake system, but noise that is propagated from the intake system to the outside of the vehicle to the intake manifold through an intake control valve connected between an intake pipe of the intake system and the intake manifold of the engine. The intake noise control approach is divided into two approaches, sound source isolation and propagation path control. The engine noise is caused by pressure fluctuation generated by the periodic opening and closing of the intake control valve.

When the inlet control valve is opened, the piston in the engine sucks air, and gas molecules adjacent to the piston move at the same speed, so that a pressure pulse is generated in an inlet system and is damped as the piston continues to move; when the air intake control valve is closed, a pressure pulse of a certain duration is also generated, so that periodic impulse noise is generated, and the noise frequency component is mainly concentrated in a low-frequency range below 200 HZ; meanwhile, vortex noise is generated when high-speed gas in the air intake process flows through the flow cross section of the air intake valve, and is mainly concentrated in a high-frequency range between 1000 and 2000HZ because the flow cross section of the air intake valve continuously changes along with the change of the opening and closing degree of the air intake control valve; if the natural frequency of the air column in the air intake system is consistent with the main frequency of the periodic air intake noise, the air column can resonate to generate resonance noise; when the air inlet control valve is closed, air pressure and speed fluctuation in the pipeline can propagate outwards from the air valve in the form of compression waves and rarefaction waves along the pipeline.

Fig. 1 is a schematic structural diagram of an air intake system provided in an embodiment of the present disclosure. Fig. 2 is a schematic view of an operation structure of an air intake system according to an embodiment of the present disclosure. As shown in fig. 1 and 2, the intake system includes a bleed air duct 1, an air cleaner 2, an intake duct 3, and at least two helmholtz silencers 4 having different resonance frequencies. Wherein, the one end of bleed pipe 1 and the access connection of air cleaner 2, the export of air cleaner 2 is connected with the one end of intake pipe 3, and two at least helmholtz silencers 4 are connected with two at least in the lateral wall of bleed pipe 1, air cleaner 2 and the lateral wall of intake pipe 3 respectively.

In the disclosed embodiment, one end of the bleed air duct 1 is adapted to communicate with the outside while the other end communicates with the inlet of the air cleaner 2, the outlet of the air cleaner 2 is connected to one end of the intake duct 3, the other end of the intake duct 3 communicates with the inlet of the intake control valve 6, and the outlet of the intake control valve 6 is adapted to communicate with the inlet of the intake manifold m1 of the engine m. When the engine m is operated, the driver operates the opening degree of the intake control valve 6 with the accelerator pedal to change the intake air amount, thereby controlling the operation of the engine. Air entering the engine m is introduced into the air cleaner 2 through the bleed air duct 1, filtered from impurities such as dust by the air cleaner 2, introduced into the engine system through the intake duct 3 and the intake control valve 6, and distributed to the cylinders of the engine m through the intake manifold m 1.

With respect to the sound waves of the periodic low-frequency impulse noise generated by the intake control valve 6 during opening and closing, the sound waves of the low-frequency impulse noise enter the at least two helmholtz silencers 4 as they propagate to the outside in the intake pipe 3, the air filter 2 and the bleed air pipe 1. The helmholtz silencer 4 generally includes a connecting pipe and a resonant cavity for connecting with an air intake system, wherein the resonant cavity is a closed cavity and has a certain natural resonant frequency, sound waves entering the helmholtz silencer 4 excite air in the cavity of the resonant cavity and generate vibration, and when the frequency of the sound waves is the same as the natural resonant frequency of the cavity of the resonant cavity, the resonant frequency is generated, at this time, the air vibration speed is the maximum, the consumed sound energy is the maximum, most of the sound waves in the helmholtz silencer are attenuated due to resonance, the other part of the sound waves are converted into heat energy due to friction damping of the helmholtz silencer 4 in the reflection process, and only a very small part of the sound waves can be reflected from the connecting pipe back to the air intake pipe 3, the air cleaner 2 or the air intake pipe 1 to continue to propagate, so as to achieve effective silencing.

In the related art, the rotating speeds of the engine are different, the noise frequencies of the generated intake noise are different, and experiments show that the low-frequency noise in the intake noise of the intake system is mainly concentrated on several frequencies.

Alternatively, the intake system of the engine includes a first helmholtz silencer 41, a second helmholtz silencer 42, and a third helmholtz silencer 43, the first helmholtz silencer 41 includes a first connection pipe 411 and a first resonance chamber 412, the first resonance chamber 412 is connected to a sidewall of the intake pipe 3 through the first connection pipe 411, the second helmholtz silencer 42 includes a second connection pipe 421 and a second resonance chamber 422, the second resonance chamber 422 is connected to the air cleaner 2 through the second connection pipe 421, the third helmholtz silencer 43 includes a third connection pipe 431 and a third resonance chamber 432, and the third resonance chamber 432 is connected to a sidewall of the intake pipe 1 through the third connection pipe 431.

In the exemplary embodiment shown in fig. 2, a helmholtz silencer 4 is connected to the side walls of the bleed air line 1, the air filter 2 and the intake air line 3, wherein at least two of the resonant frequencies of the first resonant cavity 412 of the first helmholtz silencer 41, the second resonant cavity 422 of the second helmholtz silencer 42 and the third resonant cavity 432 of the third helmholtz silencer 43 are different. For example, the resonant frequency of the first resonant cavity 412 is 89Hz, and the resonant frequency of the second resonant cavity 422 is 80 Hz. The first helmholtz silencer 41 can silence the sound wave of the low frequency impulse noise flowing through the intake pipe 3 and having a frequency of 89HZ, and the second helmholtz silencer 42 can silence the sound wave of the low frequency impulse noise flowing through the air cleaner 2 and having a frequency of 80 HZ.

In a possible embodiment, since the intake system is generally provided in the front cover of the vehicle together with other components such as the engine m, the volume of the first resonance chamber 412 of the first helmholtz silencer 41 and the volume of the second resonance chamber 422 of the second helmholtz silencer 42 are not large enough to be provided due to the small space inside the front cover of the vehicle, the amount of air contained in the chambers is small, and the acoustic energy consumed when the acoustic waves enter the chambers to resonate is also small. Therefore, the silencing capability of the air intake system is improved. By further connecting a third helmholtz silencer 43 to the bleed air pipe 1, the resonant frequency of the third resonant cavity 432 can be set to be the same as any one of the first resonant cavity 412 and the second resonant cavity 422, so that the sound wave of the low-frequency noise with the same frequency can be further silenced, and the silencing effect of the air intake system is further improved.

In another possible implementation manner, sound waves of other frequencies in the low-frequency impulse noise can also be silenced by providing a third resonant cavity 432 different from the natural resonant frequencies of the first resonant cavity 412 and the second resonant cavity 422.

Illustratively, fig. 3 is a graph of noise level of an engine provided by an embodiment of the present disclosure. As shown in FIG. 3, in the embodiment of the present disclosure, when a tester conducts noise tests on the engine and the air intake system of the automobile under various working conditions, the tester finds that the noise generated when the rotating speed of the engine m is 2153r/min and 2747r/min is most obvious. After acquiring the sound wave of the noise, the worker finds that the noise frequency is mainly concentrated in the range of 80HZ to 89HZ, so that the resonance frequencies of the first resonance cavity 412 of the first helmholtz silencer 41 and the second resonance cavity 422 of the second helmholtz silencer 42 are set to be 80HZ and 89HZ, respectively, so that the low-frequency noise of the corresponding frequency of the intake system can be effectively silenced and reduced. The low frequency noise in the intake system was 61.3dB (A) and 66.5dB (A) at 2153r/min and 2747r/min of the engine m before the first and second Helmholtz mufflers 41 and 42, respectively, and was 57.4dB (A) and 64dB (A) after the first and second Helmholtz mufflers 4 and 5, respectively, reduced by 3.9dB (A) and 2.5 (dB (A), respectively.

It should be noted that, in the embodiment of the present disclosure, the setting manner that the frequency of the first resonant cavity 412 is 89HZ, and the resonant frequency of the second resonant cavity 422 is 80HZ is merely an example, and in other possible implementation manners, the resonant frequency of the first resonant cavity 412 may be set to 80HZ, and the frequency of the second resonant cavity 422 may be set to 89HZ, as long as the sound waves corresponding to different frequencies can be muffled, which is not limited in the embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of a helmholtz silencer connected to an air cleaner according to an embodiment of the present disclosure. The dimensional relationship between the first connection pipe 411 and the first resonant cavity 412, the dimensional relationship between the second connection pipe 421 and the second resonant cavity 422, and the dimensional relationship between the third connection pipe 431 and the third resonant cavity 432 all satisfy the following formula (1):

f＝(C/2pi)*[S/(L*V)]^1/2； (1)

wherein C is the propagation velocity of sound in air, Pi is the circumferential ratio Pi, L is the length of the first connecting pipe, the second connecting pipe or the third connecting pipe, S is the sectional area of the first connecting pipe, the second connecting pipe or the third connecting pipe, and the range of S is 100 Pi-225 Pi mm²V is a volume of the first resonant cavity, the second resonant cavity, or the third resonant cavity, f is a resonance frequency, a resonance score of one of the first helmholtz silencer, the second helmholtz silencer, and the third helmholtz silencer is 80HZ, and a resonance frequency of the other of the first helmholtz silencer, the second helmholtz silencer, and the third helmholtz silencer is 89 HZ.

Taking the second connection pipe 421 and the second resonant cavity 422 of the second helmholtz silencer 42 as an example, when designing the second helmholtz silencer 42, L, S and V are only needed to be correspondingly arranged according to the above proportional relationship. The second helmholtz silencer 42 can adopt the existing design structure and shape, and the present embodiment only optimizes and improves the volume V of the second resonant cavity 422 and the length L of the second connecting pipe 421, because the space in the front cover of the vehicle body is limited, the larger the volume of the second resonant cavity 422 is, the more air is in the cavity of the second resonant cavity 422 when the space allows, the larger the sound energy consumed when the sound wave enters the cavity of the second resonant cavity 422 to generate resonance is, and the better the silencing effect is. The length L of the second connection pipe 421 is finally determined while ensuring that the volume V of the second resonant cavity 422 is as large as possible.

Exemplarily, in the embodiment of the present disclosure, the volume of the first resonant cavity 412 is 1.6L, and the length of the first connecting tube 411 is 35 mm; the volume of the second resonant cavity 422 is 5.3L, and the length of the second connection pipe 421 is 23.5 mm.

Illustratively, in the embodiment of the present disclosure, specific volumes of the first resonant cavity 412 of the first helmholtz silencer 41, the second resonant cavity 422 of the second helmholtz silencer 42, and the third resonant cavity 432 of the third helmholtz silencer 43 are not limited as long as they can perform noise reduction and sound attenuation on sound waves having the same resonance frequency f thereof by the principle of resonance.

Optionally, the air cleaner 2 comprises a cavity 21 and a screen 22, the screen 22 divides the cavity 21 into a first inner cavity 211 near the bleed air pipe 1 and a second inner cavity 212 near the intake pipe 3, and the second resonant cavity 422 communicates with the second inner cavity 212 through a second connecting pipe 421. For example, in the embodiment of the present disclosure, air entering the engine m is first introduced into the first inner cavity 211 of the air cleaner 2 through the bleed air pipe 1, and enters the second inner cavity 212 after being filtered by the filter 22 to remove impurities such as dust, and the second resonant cavity 422 is communicated with the second inner cavity 212 through the second connecting pipe 421, so that the second connecting pipe 421 can be prevented from being blocked by impurities in the air, and the second helmholtz silencer 42 cannot muffle low-frequency noise. The silencing effect and the service life of the air inlet system are improved.

Optionally, the screen 22 is a nonwoven soundproof cotton screen. Exemplarily, in the embodiment of the present disclosure, the non-woven fabric soundproof cotton filter screen is adopted for filtering, so that when the air is filtered, noise in the air intake system can be subjected to auxiliary noise reduction, and the noise reduction effect of the air intake system is further improved.

Optionally, the air intake system further comprises 1/4 wave tube 5, 1/4 wave tube 5 connected with the side wall of the air intake pipe 3. The 1/4 wave tube is a tube with one end closed, and is usually connected to the air inlet tube, for the sound wave with certain frequency, especially the sound wave of high frequency eddy noise with frequency concentrated between 1000 to 2000HZ, after entering the 1/4 wave tube, it is reflected back to the air inlet tube by the closed end of the 1/4 wave tube, and the sound wave reflected back to the air inlet tube 3 and the sound wave with the same frequency in the air inlet tube 3 cancel each other due to opposite phase, so as to realize sound attenuation and noise reduction. Exemplarily, in the embodiment of the present disclosure, by connecting 1/4 wave tubes to the side wall of the intake pipe 3, the high-frequency vortex noise that may be present can be silenced by 1/4 wave tubes, and the silencing effect of the intake system is further improved.

Optionally, referring again to fig. 1 and 2, part of the tube body of the air inlet tube 3 is a hose. Exemplarily, in the embodiment of the present disclosure, by setting a portion of the air inlet pipe 3 as a hose, the specific structure of the air inlet pipe 3 corresponding to the space in the front cover of the vehicle may be bent, so as to reduce the space of the front cover of the vehicle occupied by the air inlet pipe 3, and thus, the volume of the first resonant cavity 412, the second resonant cavity 422, or the third resonant cavity 432 is set to be larger, so as to further improve the silencing effect of the air inlet system. Fig. 5 is a schematic structural view of a connection between a helmholtz silencer and an intake pipe according to the disclosed embodiment. As shown in fig. 5, the first helmholtz silencer 41 is connected to the side wall of the intake pipe 3 by means of a resilient clip 31. Because the partial body of intake pipe 3 is the hose, can produce the damage because of reasons such as vibrations and high temperature after long-time the use easily, need often maintain or change. In the embodiment of the present disclosure, the connecting branch pipe 32 has on the side wall of the intake pipe 3, the first connecting pipe 411 of the first helmholtz silencer 41 is fixed with the connecting branch pipe 32 on the side wall of the intake pipe 3 through the locking of the elastic clamp 31, set up as detachable fixed connection through the first helmholtz silencer 41 and the intake pipe 3, when the intake pipe 3 needs to be maintained and replaced, only need to loosen the elastic clamp 31 and can separate the fourth helmholtz silencer 4 from the intake pipe 3, the replacement is maintained to the intake pipe 3 conveniently, meanwhile, the first helmholtz silencer 41 can continue to be used, the operating cost of the intake system is reduced, and the service life is prolonged.

Fig. 6 is a partial schematic structural view of an air cleaner according to an embodiment of the present disclosure. As shown in fig. 1 and 6, the housing of the cavity 21 of the air cleaner 2 is exemplarily provided with a first mounting hole 2a and a plurality of second mounting holes 2b, and when the second helmholtz silencer 42 and the air cleaner 2 are mounted, the second connection pipe 421 may be inserted into the first mounting hole 2a to communicate with the inside of the cavity 21, and the housing of the cavity 21 of the air cleaner 2 and the housing of the second resonator 422 may be fixedly connected by rivets through the plurality of second mounting holes 2 b.

The embodiment of the disclosure also provides an automobile comprising the air intake system shown in fig. 1 to 3 and 5 to 6. Through setting up two at least different helmholtz silencers 4 of resonant frequency, can carry out effective amortization to the sound wave of the low frequency noise of two at least different frequencies in the low frequency impulse noise to improve air intake system's noise cancelling effect.

The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.

Claims (10)

1. An intake system of an engine, comprising: a bleed air pipe (1), an air filter (2), an air inlet pipe (3) and at least two Helmholtz silencers (4) with different resonance frequencies,

the one end of bleed pipe (1) with the access connection of air cleaner (2), the export of air cleaner (2) with the one end of intake pipe (3) is connected, at least two helmholtz silencers (4) respectively with the lateral wall of bleed pipe (1) air cleaner (2) with at least two in the lateral wall of intake pipe (3) are connected.

2. An air inlet system according to claim 1, characterized in that the air inlet system of the engine comprises a first Helmholtz muffler (41), a second Helmholtz muffler (42) and a third Helmholtz muffler (43), the first Helmholtz silencer (41) comprises a first connecting pipe (411) and a first resonant cavity (412), the first resonant cavity (412) is connected with the side wall of the gas inlet pipe (3) through the first connecting pipe (411), the second Helmholtz silencer (42) comprises a second connecting pipe (421) and a second resonant cavity (422), the second resonant cavity (422) is connected with the air filter (2) through a second connecting pipe (421), the third Helmholtz silencer (43) comprises a third connection pipe (431) and a third resonance chamber (432), the third resonant cavity (432) is connected with the side wall of the bleed air pipe (1) through the third connecting pipe (431).

3. The air intake system according to claim 2, wherein a dimensional relationship between the first connecting pipe (411) and the first resonant cavity (412), a dimensional relationship between the second connecting pipe (421) and the second resonant cavity (422), and a dimensional relationship between the third connecting pipe (431) and the third resonant cavity (432) each satisfy the following formula:

f＝(C/2pi)*[S/(L*V)]^1/2；

wherein C is a propagation velocity of sound in air, Pi is a circumferential ratio Pi, L is a length of the first connecting pipe, the second connecting pipe or the third connecting pipe, S is a sectional area of the first connecting pipe, the second connecting pipe or the third connecting pipe, and S ranges from 100 Pi to 225 Pi mm²V is a volume of the first resonant cavity, the second resonant cavity, or the third resonant cavity, f is a resonant frequency, one of the first, second, and third helmholtz silencers has a resonant frequency of 80HZ, and the other of the first, second, and third helmholtz silencers has a resonant frequency of 89 HZ.

4. An air inlet system according to claim 3, characterized in that the air filter (2) comprises a cavity (21) and a screen (22), the screen (22) dividing the cavity (21) into a first inner cavity (211) near the bleed air duct (1) and a second inner cavity (212) near the inlet air duct (3), the second resonance chamber (422) communicating with the second inner cavity (212) through the second connection pipe (421).

5. The air intake system of claim 4, wherein the screen (22) is a nonwoven soundproof cotton screen.

6. An air inlet system according to claim 3, characterized in that the first helmholtz silencer (41) is connected to the side wall of the air inlet pipe (3) by means of a resilient clip (31).

7. An air inlet system according to any of claims 1-6, characterized in that the air inlet system further comprises 1/4 wave tube (5), the 1/4 wave tube (5) being connected with the side wall of the air inlet pipe (3).

8. The intake system according to any one of claims 1 to 6, further comprising an intake control valve (6), the intake control valve (6) being connected to the intake pipe (3).

9. An air inlet system according to any one of claims 1-6, characterized in that part of the tube body of the air inlet tube (3) is a hose.

10. An automobile, characterized by comprising an air intake system according to any one of claims 1 to 9.

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