阅读说明：本技术 一种气制动驻车回路系统 (Air braking parking loop system ) 是由 吕征 胡圣万 龙雪辉 徐冕 于 2020-06-24 设计创作，主要内容包括：本申请涉及一种气制动驻车回路系统,属于汽车制动技术领域,包括：由气路方向依次通过管路连接的空气压缩机及空气处理单元、驻车储气筒、差动式继动阀和制动弹簧缸,差动式继动阀的常进气口与驻车储气筒连通,差动式继动阀的驻车制动出气口与制动弹簧缸连通；驻车储气筒与差动式继动阀之间设有控制差动式继动阀通断的手动阀,手动阀的进气口与驻车储气筒连通,手动阀的出气口与差动式继动阀的驻车控制口连接；当手动阀打开时,驻车控制口的气压为P<Sub>4</Sub>,常进气口的气压为P<Sub>4</Sub>,驻车制动出气口的气压为P<Sub>2</Sub>,且P<Sub>2</Sub>＝n×P<Sub>4</Sub>,0＜n＜1。本申请可实现气制动驻车回路系统气压的有效调节,确保制动弹簧缸满足工作气压要求。(The application relates to a pneumatic braking parking return circuit system belongs to car braking technical field, includes: the pneumatic brake system comprises an air compressor, an air processing unit, a parking air cylinder, a differential relay valve and a brake spring cylinder which are connected in sequence through pipelines in the air path direction, wherein a normal air inlet of the differential relay valve is communicated with the parking air cylinder, and a parking brake air outlet of the differential relay valve is communicated with the brake spring cylinder; a manual valve for controlling the differential relay valve to be switched on and off is arranged between the parking air cylinder and the differential relay valve, an air inlet of the manual valve is communicated with the parking air cylinder, and an air outlet of the manual valve is connected with a parking control port of the differential relay valve; when the manual valve is opened, the air pressure of the parking control port is P 4 The air pressure of the normal air inlet is P 4 Air pressure at air outlet of parking brake is P 2 And P is 2 ＝n×P 4 N is more than 0 and less than 1. The air pressure of the air braking parking loop system can be effectively adjusted, and the brake spring cylinder is ensured to meet the requirement of working air pressure.)

1. A pneumatic brake park circuit system, comprising:

the parking brake system comprises an air compressor, an air processing unit (7), a parking air cylinder (1), a differential relay valve (6) and a brake spring cylinder (5), wherein the air compressor and the air processing unit (7), the parking air cylinder (1), the differential relay valve (6) and the brake spring cylinder (5) are sequentially connected through pipelines in the air path direction, a normal air inlet (62) of the differential relay valve (6) is communicated with the parking air cylinder (1), and a parking brake air outlet of the differential relay valve (6) is communicated with the brake spring cylinder (5);

a manual valve (3) for controlling the on-off of the differential relay valve (6) is arranged between the parking air cylinder (1) and the differential relay valve (6), an air inlet of the manual valve (3) is communicated with the parking air cylinder (1), and an air outlet of the manual valve (3) is connected with a parking control port (61) of the differential relay valve (6);

when the manual valve (3) is opened, the air pressure of the parking control port (61) is P₄The air pressure of the constant air inlet (62) is P₄The air pressure of the parking brake air outlet is P₂And P is₂＝n×P₄，0＜n＜1。

2. A pneumatic brake park circuit system as set forth in claim 1 wherein:

the differential relay valve (6) comprises a valve housing (63) and a piston located within the valve housing (63), the piston being located between the parking control port (61) and the atmospheric port (62), the piston dividing the valve housing (63) into a sealed upper chamber (66) and a sealed lower chamber (67), respectively;

a valve core is arranged between the normal-air inlet (62) and the lower chamber (67), and the valve core is used for opening and closing a first channel between the normal-air inlet (62) and the lower chamber (67);

an air inlet of the manual valve (3) is communicated with an upper chamber (66) through a parking control port (61), and the force bearing area of one end of the piston close to the upper chamber (66) is S₄The force bearing area of one end of the piston close to the lower chamber (67) is S₂And S is₂＝n×S₄，0＜n＜1，P₄×S₄＝P₂×S₂。

3. A pneumatic brake park circuit system as set forth in claim 2 wherein:

the piston is provided with a push rod (73) for pushing the valve core to open a first channel between the normal air inlet (62) and the lower chamber (67);

a gland (70) connected with the valve core in a sealing mode is further arranged in the valve shell (63), and the valve core and the gland (70) are used for closing a first channel between the normal air inlet (62) and the lower cavity (67);

the middle part of the gland (70) is provided with a through hole (74) used for penetrating the ejector rod (73), the diameter of the through hole (74) is larger than that of the ejector rod (73), and the normal air inlet (62), the through hole (74) and the lower cavity (67) form the first channel.

4. A pneumatic brake park circuit system as set forth in claim 3 wherein:

the valve core comprises a movable valve sleeve (71) and a fixed valve sleeve (72), the fixed valve sleeve (72) is fixedly arranged in the valve shell (63), and the movable valve sleeve (71) is movably sleeved on the fixed valve sleeve (72);

and a driving piece for driving the movable valve sleeve (71) to move towards the gland (70) is arranged between the movable valve sleeve (71) and the fixed valve sleeve (72).

5. The air brake park circuit system of claim 4, wherein:

the driving piece is a spiral compression spring (76), one end of the spiral compression spring (76) is abutted with the movable valve sleeve (71), and the other end of the spiral compression spring (76) is abutted with the fixed valve sleeve (72).

6. A pneumatic brake park circuit system as set forth in claim 2 wherein:

the P is₄＝1000Kpa，0.6＜n＜0.9；

The parking brake air outlet is communicated with the first channel.

7. A pneumatic brake park circuit system as set forth in claim 2 wherein:

the valve is characterized in that a guide rod (75) connected with the piston in a sliding mode is arranged in the valve shell (63), and the guide rod (75) is used for controlling the piston to do reciprocating linear motion in the direction close to and far away from the valve core.

8. A pneumatic brake park circuit system as set forth in claim 2 wherein:

an annular groove is formed in the side wall, connected with the valve shell (63) in a sliding mode, of the piston, and an annular sealing ring is arranged in the annular groove.

9. A pneumatic brake park circuit system as set forth in claim 2 wherein:

the piston comprises an upper piston (64) and a lower piston (65), the upper piston (64) and the lower piston (65) are coaxially and movably connected in a sealing manner, and an intermediate chamber (68) is formed between the upper piston (64) and the lower piston (65);

a service brake control port (69) is formed in the valve shell (63), and the service brake control port (69) is communicated with the middle chamber (68);

the service brake control port (69) is used for controlling the lower piston (65) to move towards the direction close to the valve core, so that the valve core opens a first channel between the normal air inlet port (62) and the lower chamber (67).

10. A pneumatic brake park circuit system as set forth in claim 9 wherein:

the force bearing area of one end of the upper piston (64) close to the upper chamber (66) is S₄The force bearing area of one end of the lower piston (65) close to the lower chamber (67) is S₂。

Technical Field

The application relates to the technical field of automobile braking, in particular to a pneumatic braking parking loop system.

Background

The pneumatic brake parking system of the commercial vehicle generally adopts a gas-cut type spring brake form, compressed air in a wheel-side spring brake cylinder needs to be exhausted when the vehicle is parked, and the wheel-side spring brake cylinder needs to be inflated to release the wheel-side parking brake in the starting and running processes of the vehicle, so that the wheel-side spring brake cylinder is always in an inflated state in the running process of the vehicle. The spring brake cylinder is limited by the structure, the working air pressure in the inflation state of the spring brake cylinder is not more than 900kPa, and the risk of air leakage exists if the input air pressure is higher.

The structure of the pneumatic brake parking circuit of the conventional commercial vehicle is shown in fig. 1. The brake system provides compressed air with certain air pressure for the parking loop, the pressure limiting valve 2 and the parking air storage cylinder 1 are controlled by the manual control valve 3, and then the compressed air flows through an air outlet at the output end of the parking relay valve 4 and finally reaches the wheel end brake spring cylinder 5.

GB7258-2017 requires that for vehicle types matched with air suspensions or disc brakes, the pressure of an air cylinder braking system is not lower than 1000kPa, and the working air pressures of air cylinders and valves of an air braking system in the industry are generally 1000kPa (such as a pressure limiting valve 2, a manual valve 3 and a parking relay valve 4).

In order to ensure that the air pressure of the brake spring cylinder 5 is not higher than 900kPa and simultaneously meet the air supply pressure of a brake system of 1000kPa, the existing technical scheme is that a pressure limiting valve 2 is additionally arranged at the air inlet end of a parking air cylinder 1, the pressure limiting valve 2 can realize the function of reducing the air pressure, namely the air pressure entering the parking air cylinder 1 is reduced to below 850kPa, then the working air pressure of parts (the air cylinder 1, a manual valve 3 and a parking relay valve 4) of a parking loop is reduced, and finally the working air pressure of the brake spring cylinder 5 is ensured not to exceed 850kPa (lower than the upper limit value of 900 kPa).

However, considering that the pressure limiting valve 2 may fail (performance degradation and user misadjustment) in the actual use process, the output air pressure of the pressure limiting valve 2 may be higher and lower, for example, an excessively high air pressure (over 900kPa) may cause air leakage of the brake spring cylinder 5 to cause automatic locking of wheels during the vehicle running process, and an excessively low air pressure may cause insufficient air pressure inside the brake spring cylinder 5 to release the parking brake to start the vehicle (the minimum starting air pressure of the brake spring cylinder 5 is 520kPa), thereby bringing potential safety hazards to driving and parking. Meanwhile, the air brake parking loop is additionally provided with the pressure limiting valve 2, so that the weight and the cost are increased.

Disclosure of Invention

The embodiment of the application provides an air brake parking return circuit system to solve the problem that the air brake parking return circuit additionally increases the pressure limiting valve and probably has failure in the correlation technique, and the pressure limiting valve output air pressure can have on the high side and on the low side, brings the potential safety hazard for driving and parking.

The embodiment of the application provides a pneumatic braking parking return circuit system, includes:

the parking brake system comprises an air compressor, an air processing unit, a parking air cylinder, a differential relay valve and a brake spring cylinder which are connected in sequence through pipelines in the air path direction, wherein a normal air inlet of the differential relay valve is communicated with the parking air cylinder, and a parking brake air outlet of the differential relay valve is communicated with the brake spring cylinder;

a manual valve for controlling the on-off of the differential relay valve is arranged between the parking air cylinder and the differential relay valve, the air inlet of the manual valve is communicated with the parking air cylinder, and the air outlet of the manual valve is connected with a parking control port of the differential relay valve;

when the manual valve is opened, the air pressure of the parking control port is P₄The air pressure of the constant air inlet is P₄The air pressure of the parking brake air outlet is P₂And P is₂＝n×P₄，0＜n＜1。

In some embodiments: the differential relay valve comprises a valve shell and a piston positioned in the valve shell, the piston is positioned between a parking control port and the normal air inlet port, and the piston divides the valve shell into an upper sealed chamber and a lower sealed chamber respectively;

a valve core is arranged between the normal air inlet and the lower cavity and used for opening and closing a first channel between the normal air inlet and the lower cavity;

the air inlet of the manual valve is controlled by parkingThe opening is communicated with the upper chamber, and the stress area of one end of the piston close to the upper chamber is S₄The force bearing area of one end of the piston close to the lower chamber is S₂And S is₂＝n×S₄，0＜n＜1，P₄×S₄＝P₂×S₂。

In some embodiments: the piston is provided with a push rod for pushing the valve core to open a first channel between the normal air inlet and the lower cavity;

the valve shell is internally provided with a valve core, and the valve core and the valve cover are used for closing a first channel between the normal air inlet and the lower cavity;

the middle part of the gland is provided with a through hole for penetrating the ejector rod, the diameter of the through hole is larger than that of the ejector rod, and the atmospheric port, the through hole and the lower cavity form the first channel.

In some embodiments: the valve core comprises a movable valve sleeve and a fixed valve sleeve, the fixed valve sleeve is fixedly arranged in the valve shell, and the movable valve sleeve is movably sleeved on the fixed valve sleeve;

and a driving piece for driving the movable valve sleeve to move towards the gland is arranged between the movable valve sleeve and the fixed valve sleeve.

In some embodiments: the driving piece is a spiral compression spring, one end of the spiral compression spring is abutted to the movable valve sleeve, and the other end of the spiral compression spring is abutted to the fixed valve sleeve.

In some embodiments: the P is₄＝1000Kpa，0.6＜n＜0.9；

The parking brake air outlet is communicated with the first channel.

In some embodiments: and a guide rod in sliding connection with the piston is arranged in the valve shell and is used for controlling the piston to linearly move back and forth in the direction close to and far away from the valve core.

In some embodiments: an annular groove is formed in the side wall, connected with the valve shell in a sliding mode, of the piston, and an annular sealing ring is arranged in the annular groove.

In some embodiments: the piston comprises an upper piston and a lower piston, the upper piston and the lower piston are coaxially and movably connected in a sealing manner, and a middle chamber is formed between the upper piston and the lower piston;

a service brake control port is arranged on the valve shell and is communicated with the middle cavity;

the service brake control port is used for controlling the lower piston to move towards the direction close to the valve core, so that the valve core is used for opening a first channel between the normal air inlet and the lower cavity chamber.

In some embodiments: the stress area of one end of the upper piston close to the upper chamber is S₄The force bearing area of one end of the lower piston close to the lower chamber is S₂。

The beneficial effect that technical scheme that this application provided brought includes:

the embodiment of the application provides an air brake parking loop system, which is characterized in that an air compressor, an air processing unit, a parking air cylinder, a differential relay valve and a brake spring cylinder are sequentially connected through a pipeline in an air path direction, a constant air inlet of the differential relay valve is communicated with the parking air cylinder, and a parking brake air outlet of the differential relay valve is communicated with the brake spring cylinder; a manual valve for controlling the differential relay valve to be switched on and off is arranged between the parking air cylinder and the differential relay valve, an air inlet of the manual valve is communicated with the parking air cylinder, and an air outlet of the manual valve is connected with a parking control port of the differential relay valve; when the manual valve is opened, the air pressure of the parking control port is P₄The air pressure of the normal air inlet is P₄Air pressure at air outlet of parking brake is P₂And P is₂＝n×P₄，0＜n＜1。

Therefore, the air pressure of the parking control port of the differential relay valve is P₄The air pressure of the normal air inlet of the differential relay valve is P₄The air pressure of the parking brake air outlet of the differential relay valve is P₂. Air pressure P of normal air inlet₄Air pressure P greater than air outlet of parking brake₂The effective air pressure of the air braking parking loop system can be realizedAnd adjusting to ensure that the brake spring cylinder meets the working air pressure requirement. Meanwhile, the air brake parking loop system omits a pressure limiting valve, simplifies the air path form of the air brake parking loop system, and is low in cost and high in reliability.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a pneumatic braking parking circuit of a commercial vehicle in the prior art;

FIG. 2 is a block diagram of an air brake park circuit system according to an embodiment of the present application;

fig. 3 is a sectional view of the differential relay valve according to the embodiment of the present application.

Reference numerals:

1. parking the air cylinder; 2. a pressure limiting valve; 3. a manual valve; 4. a parking relay valve; 5. a brake spring cylinder; 6. a differential relay valve; 7. an air compressor and an air processing unit;

61. a parking control port; 62. a normal air inlet; 63. a valve housing; 64. an upper piston; 65. a lower piston; 66. an upper chamber; 67. a lower chamber; 68. an intermediate chamber; 69. a service brake control port; 70. a gland; 71. a movable valve sleeve; 72. a fixed valve sleeve; 73. pushing the push rod; 74. a through hole; 75. a guide bar; 76. the coil compresses the spring.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides an air brake parking return circuit system, and it can solve among the relevant art air brake parking return circuit and additionally increase the pressure limiting valve and probably have the inefficacy, and pressure limiting valve output pressure can exist on the high side and on the low side, brings the problem of potential safety hazard for driving and parking.

Referring to fig. 2 and 3, an embodiment of the present application provides a pneumatic brake parking circuit system, including:

the air pressure and air processing unit 7, the parking air cylinder 1, the differential relay valve 6 and the brake spring cylinder 5 are connected in sequence through pipelines in the air path direction, a normal air inlet 62 of the differential relay valve 6 is communicated with the parking air cylinder 1, and a parking brake air outlet (not shown in the figure) of the differential relay valve 6 is communicated with the brake spring cylinder (5).

And a manual valve 3 for controlling the on-off of the normal air inlet 62 and the parking brake air outlet of the differential relay valve 6 is arranged between the parking air cylinder 1 and the differential relay valve 6. The inlet port of the manual valve 3 communicates with the parking cylinder 1, and the outlet port of the manual valve 3 communicates with the parking control port 61 of the differential relay valve 6. The manual valve 3 is used for triggering the normal air inlet 62 and the parking brake air outlet of the differential relay valve 6 to be switched on and off.

When the manual valve 3 is opened, the normal air inlet 62 of the differential relay valve 6 and the parking brake air outlet are triggered to communicate under the drive of compressed air introduced into the manual valve 3. Since the parking control port 61 and the constant air inlet port 62 are both communicated with the parking air cylinder 1, the pressure of the parking control port 61 and the constant air inlet port 62 is the same, i.e. the air pressure of the parking control port 61 is P₄The atmospheric pressure of the atmospheric inlet 62 is P₄The air pressure at the parking brake air outlet of the differential relay valve 6 is P₂And P is₂＝n×P₄，0＜n＜1。

P of the embodiment of the present application₄1000Kpa, 0.6 < n < 0.9, when n is 0.85, P₂850Kpa, when n is taken to be 0.55, P₂The specific value 550Kpa, n may be set by those skilled in the art according to the specific use requirement of the air pressure of the parking cylinder 1 and the air pressure of the brake spring cylinder 5.

The air pressure P of the common air inlet 62₄Air pressure P greater than air outlet of parking brake₂The effective regulation of the air pressure of the air braking parking loop system can be realized, and the brake spring cylinder 5 is ensured to meet the requirement of working air pressure.

In some alternative embodiments: referring to fig. 3, the present embodiment provides an air brake parking circuit system, in which a differential relay valve 6 includes a valve housing 63 and a piston disposed in the valve housing 63, the valve housing 63 is a hollow structure, the valve housing 63 is divided into an upper housing and a lower housing, and the upper housing and the lower housing are detachably and hermetically connected.

The piston is positioned between the parking control port 61 and the normal air inlet 62, the piston respectively forms the valve housing 63 into an upper sealed chamber 66 and a lower sealed chamber 67, and the piston can drive the piston to linearly move in the valve housing 63 under the action of compressed air introduced into the parking control port 61.

A valve spool for opening and closing a first passage between the atmospheric port 62 and the lower chamber 67 is provided between the atmospheric port 62 and the lower chamber 67. The parking brake air outlet is communicated with the first channel, when the valve core is used for opening the first channel between the normal air inlet 62 and the lower chamber 67, compressed air in the first channel is introduced into the parking brake air outlet, and compressed air is introduced into the brake spring cylinder 5 from the parking brake air outlet.

The air inlet of the manual valve 3 is communicated with the upper chamber 66 through the parking control port 61, and the force bearing area of one end of the piston close to the upper chamber 66 is S₄The force area of the piston near the lower chamber 67 is S₂And S is₂＝n×S₄，0＜n＜1，P₄×S₄＝P₂×S₂. The area of the piston vertically pushed by the compressed air in the upper chamber 66 is the force bearing area of the piston approaching the upper chamber 66. The area of the piston which is vertically pushed by the compressed air in the lower chamber 67 to move linearly is the stressed area of the piston which is close to the lower chamber 67.

When the driver performs parking and parking release operations on the manual control valve, the driver moves the upper part of the interior of the parking relay valveThe lower piston satisfies the mechanical balance according to the mechanical formula P₄×S₄＝P₂×S₂To thereby yield P₂:P₄＝S₄:S₂The design is such that the force-bearing area S of the piston near the end of the upper chamber 66₄The force-receiving area is small relative to the end of the piston near the lower chamber 67. For example: the ratio of the two S₄:S₂0.85: 1, obtaining P₂:P₄0.85: 1, i.e. the air pressure characteristic of the parking brake air outlet of the differential relay valve 6 satisfies P₂＝0.85xP₄。

In some alternative embodiments: referring to fig. 3, the present embodiment provides a pneumatic brake parking circuit system, in which a push rod 73 for pushing a spool to open a first passage between a normal air inlet 62 and a lower chamber 67 is provided on a piston of a differential relay valve 6;

a gland 70 connected with the valve core in a sealing way is further arranged in the valve shell 63, and when the valve core is combined with the gland 70, the first channel between the normal air inlet 62 and the lower chamber 67 is closed; the valve spool is disengaged from the gland 70 to open the first passage between the inlet port 62 and the lower chamber 67.

The middle part of the gland 70 is provided with a through hole 74 for penetrating the ejector pin 75, the diameter of the through hole 74 is larger than that of the ejector pin 75, and the atmospheric inlet 62, the through hole 74 and the lower chamber 67 together form the first channel.

In some alternative embodiments: referring to fig. 3, the embodiment of the present application provides an air brake parking circuit system, in which a valve core of a differential relay valve 6 of the air brake parking circuit system includes a movable valve sleeve 71 and a fixed valve sleeve 72, the fixed valve sleeve 72 is fixedly disposed in a valve housing 63, and the movable valve sleeve 71 is movably sleeved on the fixed valve sleeve 73.

A driving member for driving the movable valve sleeve to move in the direction of the gland is provided between the movable valve sleeve 71 and the fixed valve sleeve 72. The driving member is a coil compression spring 76, one end of the coil compression spring 76 abuts against the movable valve sleeve 71, and the other end of the coil compression spring 76 abuts against the fixed valve sleeve 72.

When the push rod 73 of the piston does not push the valve sleeve 71 to move toward the fixed valve sleeve 72, the helical compression spring 76 between the valve sleeve 71 and the fixed valve sleeve 72 drives the valve sleeve 71 to be coupled with the gland 70, so that the valve core closes the first passage between the normal-air inlet port 62 and the lower chamber 67.

When the push rod 73 of the piston pushes the valve sleeve 71 to move towards the fixed valve sleeve 72, the helical compression spring 76 between the valve sleeve 71 and the fixed valve sleeve 72 retracts, and the push rod 73 of the piston drives the valve sleeve 71 to disengage from the gland 70, so that the valve core opens a first channel between the normal air inlet 62 and the lower chamber 67.

A guide rod 75 is slidably connected to the piston within the valve housing 63, the guide rod 75 being configured to control the reciprocating linear movement of the piston in a direction toward and away from the valve cartridge, the guide rod 75 providing a guide for the movement of the piston.

In some alternative embodiments: referring to fig. 3, the present embodiment provides a pneumatic brake parking circuit system, in which a piston of a differential relay valve 6 includes an upper piston 64 and a lower piston 65, the upper piston 64 and the lower piston 65 are coaxially and movably connected in a sealing manner, and the upper piston 64 and the lower piston 65 can move synchronously and relatively in a valve housing 63. Annular grooves are formed in the side walls of the upper piston 64, the lower piston 65 and the valve shell 63 in sliding connection, annular sealing rings are arranged in the annular grooves, and the upper piston 64, the lower piston 65 and the valve shell 63 are sealed through the annular sealing rings.

An intermediate chamber 68 is formed between the upper piston 64 and the lower piston 65, and a service brake control port 69 is provided in the valve housing 63, the service brake control port 69 communicating with the intermediate chamber 68. The service brake control port 69 is used to control the lower piston 65 to move toward the valve spool, so that the valve spool opens the first passage between the normal air inlet port 2 and the lower chamber 67.

The upper piston 64 has a force-bearing area S at one end thereof adjacent to the upper chamber 66₄The force-bearing area of the end of the lower piston 65 close to the lower chamber 67 is S₂。

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.