阅读说明：本技术 准零刚度隔振器 (Quasi-zero stiffness vibration isolator ) 是由 李�昊 邓泽华 李奇 于 2021-06-22 设计创作，主要内容包括：本发明提供了一种准零刚度隔振器,包括振动输出部件(1)、传动组件、振动输入部件以及多个弹性部件；所述传动组件的一端可滑动的安装在所述振动输入部件的内部并连接所述弹性部件,传动组件的另一端穿过振动输入部件的顶端延伸到振动输入部件的外部并与振动输出部件(1)连接；振动输入部件的底端为振动输入端,用于与外部振动源相连。本发明利用弹性部件的弯曲大变形实现准零刚度特性,内部无复杂的负刚度结构及机构,结构简单,对制造精度要求低,零刚度区间大,不需要外部供给能量,方便小型化和轻量化。(The invention provides a quasi-zero stiffness vibration isolator which comprises a vibration output part (1), a transmission assembly, a vibration input part and a plurality of elastic parts, wherein the vibration output part is connected with the transmission assembly; one end of the transmission assembly is slidably arranged in the vibration input component and connected with the elastic component, and the other end of the transmission assembly penetrates through the top end of the vibration input component to extend to the outside of the vibration input component and is connected with the vibration output component (1); the bottom end of the vibration input component is a vibration input end and is used for being connected with an external vibration source. The invention realizes the quasi-zero stiffness characteristic by utilizing the large bending deformation of the elastic component, has no complex negative stiffness structure and mechanism inside, has simple structure, low requirement on manufacturing precision, large zero stiffness interval and no need of external energy supply, and is convenient for miniaturization and light weight.)

1. The quasi-zero stiffness vibration isolator is characterized by comprising a vibration output component (1), a transmission assembly, a vibration input component and a plurality of elastic components;

one end of the transmission assembly is slidably arranged in the vibration input component and connected with the elastic component, and the other end of the transmission assembly penetrates through the top end of the vibration input component to extend to the outside of the vibration input component and is connected with the vibration output component (1);

the bottom end of the vibration input component is a vibration input end and is used for being connected with an external vibration source.

2. The quasi-zero stiffness vibration isolator according to claim 1, wherein the transmission assembly comprises a connecting rod (2) and an inner slide block (3);

one end of the connecting rod (2) is fixedly connected with the vibration output component (1), and the other end of the connecting rod (2) penetrates through the top end of the vibration input component, extends into the vibration input component and is connected with an inner sliding block (3) capable of sliding in the vibration input component.

3. A quasi-zero stiffness vibration isolator according to claim 2 wherein the elastomeric members include elastomeric sheets (5), major axes (6) and minor axes (7);

the cross section of the elastic thin plate (5) is of a U-shaped structure in an assembly state, one end of the U-shaped opening side of the elastic thin plate (5) is fixedly connected with the long shaft (6), and the other end of the U-shaped opening side of the elastic thin plate (5) is fixedly connected with the short shaft (7);

the long shaft (6) is rotatably connected with the vibration input part, and the short shaft (7) is rotatably arranged on the inner slide block (3).

4. The quasi-zero stiffness vibration isolator according to claim 3, characterized in that the elastic sheet (5) is a U-shaped structure formed by bending a flat plate elastically;

the elastic thin plate (5) is a flat plate in a free state, and the bending curvature is 0;

the elastic thin plate (5) comprises a first flat plate surface, an arc-shaped surface and a second flat plate surface;

the first flat plate surface is connected with the second flat plate surface through an arc-shaped surface, wherein the first flat plate surface is parallel to the second flat plate surface in an assembly state; the end part of the first flat plate surface, which is far away from the arc-shaped surface, is connected with the long shaft (6), and the end part of the second flat plate surface, which is far away from the arc-shaped surface, is connected with the short shaft (7).

5. A quasi-zero stiffness vibration isolator according to claim 3, characterized in that the surface of the inner slide (3) has a recess into which the stub shaft (7) snaps.

6. A quasi-zero stiffness vibration isolator according to claim 3, characterized in that the material of the elastic sheet (5) is carbon fiber reinforced composite.

7. The quasi-zero stiffness vibration isolator according to claim 3, characterized in that rectangular grooves are formed in the long shaft (6) and the short shaft (7), one end of the elastic thin plate (5) is inserted into the rectangular groove in the long shaft (6) and bonded with the rectangular groove in the long shaft (6), and the other end of the elastic thin plate (5) is inserted into the rectangular groove in the short shaft (7) and bonded with the rectangular groove in the short shaft (7).

8. A quasi-zero stiffness vibration isolator according to claim 3 wherein the vibration input component is an outer frame (4) comprising a top plate (16), a bottom plate (17), a first side plate (18) and a second side plate (19);

a first through hole is formed in the top plate (16);

grooves are formed in the inner surface of the top plate and/or the inner surface of the bottom plate;

the first side plate (18) and the second side plate (19) are provided with chutes and through holes;

the connecting rod (2) penetrates through the first through hole to be connected with the inner sliding block (3);

two ends of the inner sliding block (3) are respectively installed in sliding grooves in the first side plate (18) and the second side plate (19), and the inner sliding block (3) can slide along the sliding grooves;

the long shaft (6) is clamped in the inner surface groove of the top plate and/or the inner surface groove of the bottom plate, and the end part of the long shaft (6) is rotatably arranged on the through hole.

9. The quasi-zero stiffness vibration isolator according to claim 8, characterized in that the upper surface of the inner slide (3) has a first groove and a second groove arranged in parallel, and the lower surface of the inner slide (3) has a third groove and a fourth groove arranged in parallel;

the number of the elastic parts is eight, and the elastic parts are named as a first elastic element (8), a second elastic element (9), a third elastic element (10), a fourth elastic element (11), a fifth elastic element (12), a sixth elastic element (13), a seventh elastic element (14) and an eighth elastic element respectively; the arrangement of eight said elastic members is as follows:

a first elastic element (8), a second elastic element (9), a third elastic element (10) and a fourth elastic element (11) are arranged on the inner sliding block (3);

short shafts of the first elastic element (8) and the second elastic element (9) are clamped into the first groove;

the long shafts of the first elastic element (8) and the second elastic element (9) are clamped into a fifth groove of the top plate (16), and the ends of the long shafts of the first elastic element (8) and the second elastic element (9) are respectively arranged on a second through hole (20) and a third through hole (21) of the first side plate (18) and the second side plate (19);

the third elastic element (10) and the fourth elastic element (11) are respectively arranged along a first plane with the first elastic element (8) and the second elastic element (9) symmetrically; the first plane is a longitudinal section of the inner sliding block (3);

the fifth elastic element (12), the sixth elastic element (13), the seventh elastic element (14) and the eighth elastic element are respectively symmetrical to the first elastic element (8), the second elastic element (9), the third elastic element (10) and the fourth elastic element (11) relative to the inner sliding block (3).

10. The quasi-zero stiffness vibration isolator according to claim 1, characterized in that the static stiffness of the vibration isolator as a whole can be changed by adjusting the length and/or thickness of the thin elastomeric sheet (5).

Technical Field

The invention relates to the technical field of vibration and noise control, in particular to a quasi-zero stiffness vibration isolator.

Background

The precise vibration isolation device is particularly important for high-precision equipment such as photoetching machines, ultrahigh-precision space cameras and spacecraft platforms. The precise vibration isolation device can effectively isolate micro-vibration in high-precision equipment and prevent the vibration from being transmitted outwards from a vibration source. The quasi-zero stiffness vibration isolator is a nonlinear vibration isolator and has the characteristics of high static stiffness and low dynamic stiffness.

At present, a conventional design method of a quasi-zero stiffness vibration isolator is to connect a positive stiffness component and a negative stiffness component in parallel so as to realize the characteristics of high static stiffness and low dynamic stiffness. However, three problems are generally existed in the existing design scheme of combining positive and negative stiffness components to realize the quasi-zero stiffness vibration isolator. Firstly, the negative stiffness part is too complex, a plurality of parts are required to be connected in a special way, the negative stiffness characteristic can be realized only by means of external energy and pretightening force, the whole structure is difficult to miniaturize and lighten, and the overall reliability is lower; secondly, the zero stiffness interval of the existing quasi-zero stiffness vibration isolator is generally too small, so that the vibration isolator can only effectively isolate vibration with lower vibration magnitude in a low frequency range and cannot act as a force for low-frequency and large-amplitude vibration; thirdly, the basic principle of the combination of positive and negative stiffness has high requirement on the stiffness matching accuracy of the positive stiffness part and the negative stiffness part in the vibration isolator, and the quasi-zero stiffness part is difficult to actually realize zero dynamic stiffness characteristic under the influence of processing errors and material errors, so that the actual vibration isolation effect is greatly reduced.

Patent document CN 106402262B discloses a stiffness-adjustable magnetic quasi-zero stiffness vibration isolator that uses a rectangular permanent magnet to generate negative stiffness and an elastic bag body to provide positive stiffness; when the load changes, the working position of the elastic bag body is controlled to be unchanged, the positive rigidity of the elastic bag body is changed due to the change of the internal pressure of the elastic bag body, and then the negative rigidity is matched with the positive rigidity by adjusting the distance between the rectangular magnets. However, the principle of combining the positive stiffness component and the negative stiffness component is still adopted, and the problems of complex equipment, external energy requirement and the like exist.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a quasi-zero stiffness vibration isolator.

The invention provides a quasi-zero stiffness vibration isolator which comprises a vibration output part, a transmission assembly, a vibration input part and a plurality of elastic parts, wherein the vibration output part is connected with the transmission assembly;

one end of the transmission assembly is slidably arranged in the vibration input component and connected with the elastic component, and the other end of the transmission assembly penetrates through the top end of the vibration input component to extend to the outside of the vibration input component and is connected with the vibration output component;

the bottom end of the vibration input component is a vibration input end and is used for being connected with an external vibration source.

Preferably, the transmission assembly comprises a connecting rod and an inner sliding block;

one end of the connecting rod is fixedly connected with the vibration output component, and the other end of the connecting rod penetrates through the top end of the vibration input component, extends to the inside of the vibration input component and is connected with an inner sliding block capable of sliding in the vibration input component.

Preferably, the elastic member includes an elastic sheet, a major axis, and a minor axis;

the cross section of the elastic thin plate is of a U-shaped structure in an assembling state, one end of the U-shaped opening side of the elastic thin plate is fixedly connected with the long shaft, and the other end of the U-shaped opening side of the elastic thin plate is fixedly connected with the short shaft;

the long shaft is rotatably connected with the vibration input part, and the short shaft is rotatably arranged on the inner slide block.

Preferably, the elastic thin plate (5) is of a U-shaped structure formed by bending a flat plate elastically;

the elastic thin plate (5) is a flat plate in a free state, and the bending curvature is 0;

the elastic thin plate comprises a first flat plate surface, an arc-shaped surface and a second flat plate surface;

the first flat plate surface is connected with the second flat plate surface through an arc-shaped surface, wherein the first flat plate surface is parallel to the second flat plate surface in an assembly state; the end part of the first flat plate surface, which is far away from the arc-shaped surface, is connected with the long shaft, and the end part of the second flat plate surface, which is far away from the arc-shaped surface, is connected with the short shaft.

Preferably, the bending stiffness of the first and second flat plate surfaces is greater than the bending stiffness of the arc-shaped surface.

Preferably, the surface of the inner slide block is provided with a groove, and the short shaft is clamped in the groove.

Preferably, the elastic sheet material is a carbon fiber reinforced composite material.

Preferably, rectangular grooves are formed in the long shaft and the short shaft, one end of the elastic thin plate is inserted into the rectangular groove in the long shaft and is bonded with the rectangular groove in the long shaft, and the other end of the elastic thin plate is inserted into the rectangular groove in the short shaft and is bonded with the rectangular groove in the short shaft.

Preferably, the vibration input member is an outer frame including a top plate, a bottom plate, a first side plate, and a second side plate;

the top plate is provided with a first through hole;

grooves are formed in the inner surface of the top plate and the inner surface of the bottom plate;

the first side plate and the second side plate are both provided with a chute and a through hole;

the connecting rod penetrates through the first through hole to be connected with the inner sliding block;

two ends of the inner sliding block are respectively installed in sliding grooves in the first side plate and the second side plate, and the inner sliding block can slide along the sliding grooves;

the long shaft is clamped in the inner surface groove of the top plate and/or the inner surface groove of the bottom plate, and the end part of the long shaft is rotatably arranged on the through hole.

Preferably, the upper surface of the inner sliding block is provided with a first groove and a second groove which are arranged in parallel, and the lower surface of the inner sliding block is provided with a third groove and a fourth groove which are arranged in parallel;

the number of the elastic components is eight, and the eight elastic components are named as a first elastic element, a second elastic element, a third elastic element, a fourth elastic element, a fifth elastic element, a sixth elastic element, a seventh elastic element and an eighth elastic element respectively; the arrangement of the eight elastic members is as follows; the arrangement of the eight elastic members is as follows:

a first elastic element, a second elastic element, a third elastic element and a fourth elastic element are arranged above the inner sliding block;

short shafts of the first elastic element and the second elastic element are clamped in the first groove;

the long shafts of the first elastic element and the second elastic element are clamped into a fifth groove of the top plate, and the ends of the long shafts of the first elastic element and the second elastic element are respectively arranged on a second through hole and a third through hole of the first side plate and the second side plate;

the third elastic element and the fourth elastic element are respectively and symmetrically arranged with the first elastic element and the second elastic element along a first plane; the first plane is a longitudinal section of the inner slide block;

the fifth elastic element, the sixth elastic element, the seventh elastic element and the eighth elastic element are respectively symmetrical with the first elastic element, the second elastic element, the third elastic element and the fourth elastic element relative to the inner slide block (3).

Preferably, the static rigidity of the whole vibration isolator can be changed by adjusting the length and/or the thickness of the elastic thin plate (5).

Compared with the prior art, the invention has the following beneficial effects:

1. the invention realizes the quasi-zero rigidity characteristic by utilizing the bending large deformation of the elastic component, has no complex mechanism because the elastic thin plate is arranged inside, has simple structure, does not need external energy supply, and is convenient for miniaturization and light weight.

2. The invention utilizes the characteristic that the elastic sheet can keep zero rigidity in a larger bending deformation range, and the whole vibration isolator has a larger zero rigidity interval and can be applied to occasions with larger vibration magnitude.

3. The invention realizes the quasi-zero stiffness characteristic by utilizing the bending large deformation of the elastic thin plate, the material error and the processing error of the elastic thin plate only influence the static bearing capacity of the elastic thin plate and have no influence on the zero stiffness characteristic of the elastic thin plate in a large bending state, so the requirements of the invention on processing and manufacturing are reduced.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic overall view of the present invention;

FIG. 2 is an overall exploded view of the present invention;

FIG. 3 is a schematic view of the external appearance of the present invention;

FIG. 4(a) is a schematic cross-sectional view of the present invention;

FIG. 4(b) is a schematic cross-sectional view of the present invention as the vibration input member is moved downward;

FIG. 5 is a schematic view of the elastic sheet of the present invention before and after installation.

The figures show that:

vibration output member-1

Connecting rod-2

Inner slide block-3

Outer frame-4

Elastic sheet-5

Major axis-6

Short axis-7

First elastic element-8

Second elastic element-9

The third elastic element-10

Fourth elastic element-11

The fifth elastic element-12

Sixth elastic element-13

Seventh elastic element-14

Top board-16

Baseboard-17

A first side plate-18

Second side plate-19

Second through hole-20

Third through hole-21

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

The invention provides a quasi-zero stiffness vibration isolator which comprises a vibration output part 1, a transmission assembly, a vibration input part and a plurality of elastic parts. One end of the transmission assembly is slidably arranged in the vibration input component and connected with the elastic component, the other end of the transmission assembly penetrates through the top end of the vibration input component, extends to the outside of the vibration input component and is connected with the vibration output component 1, the transmission assembly is used for transmitting the resultant force of the vibration input component and the elastic component to the vibration output component 1, and the bottom end of the vibration input component is a vibration input end and is used for being connected with an external vibration source. After the vibration is transmitted into the quasi-zero stiffness vibration isolator by an external vibration source, the quasi-zero stiffness vibration isolator has stronger static bearing capacity by using the elastic restoring force of the elastic part, and meanwhile, the whole dynamic stiffness of the vibration isolator is 0 so as to achieve the effect of vibration isolation.

The transmission assembly comprises a connecting rod 2 and an inner sliding block 3. One end of the connecting rod 2 is fixedly connected with the vibration output component 1, and the other end of the connecting rod 2 passes through the top end of the vibration input component, extends to the inside of the vibration input component and is connected with an inner slide block 3 capable of sliding in the inside of the vibration input component. In a preferred embodiment, the vibration output part 1 is connected with the upper end of the connecting rod 2 through a thread, and the lower end of the connecting rod 2 is also connected with the inner slide block 3 through a thread.

The elastic member includes an elastic sheet 5, a major axis 6, and a minor axis 7. In a preferred embodiment, the elastic sheet 5 is made of carbon fiber reinforced composite material, and has a thickness of 0.5mm, a length of 100mm and a width of 30 mm.

The cross section of the elastic thin plate 5 is in a U-shaped structure in an assembling state, one end of the U-shaped opening side of the elastic thin plate 5 is fixedly connected with the long shaft 6, and the other end of the U-shaped opening side of the elastic thin plate 5 is fixedly connected with the short shaft 7; the long shaft 6 is rotatably connected to the vibration input member. The short shaft 7 is rotatably mounted on the inner slide 3. When the quasi-zero stiffness vibration isolator works, the elastic thin plate 5 deforms, and the long shaft 6 and the short shaft 7 are driven to rotate relative to the vibration input component. As shown in fig. 5, in a preferred embodiment, the elastic sheet 5 is made of a flat plate with an initial bending curvature of 0 in a free state and in a flat state, rectangular grooves are formed on the long axis 6 and the short axis 7, one end of the elastic sheet 5 is inserted into the rectangular groove on the long axis 6 and bonded with the rectangular groove on the long axis 6, the other end of the elastic sheet 5 is inserted into the rectangular groove on the short axis 7 and bonded with the rectangular groove on the short axis 7, and the elastic sheet is bent into a U shape by external force, and at this time, the elastic sheet 5 is in a U-shaped structure formed by elastically bending the flat plate.

The elastic sheet 5 comprises a first flat plate surface, an arc-shaped surface and a second flat plate surface; the first plate surface is connected with the second plate surface through the arc-shaped surface. In an assembly state, the first flat plate surface is parallel to the second flat plate surface, but in an operating state of the quasi-zero stiffness vibration isolator, external force acts on the quasi-zero stiffness vibration isolator, so that the first flat plate surface is not necessarily parallel to the second flat plate surface. The end part of the first flat plate surface far away from the arc-shaped surface is connected with the long shaft 6, and the end part of the second flat plate surface far away from the arc-shaped surface is connected with the short shaft 7. The elastic thin plate 5 is in a bending large deformation state under the restraint of the outer frame 4 and the inner slide block 3 through the long shaft 6 and the short shaft 7, the elastic force of the elastic thin plate 5 is transmitted to the outer frame and the inner slide block through the long shaft 6 and the short shaft 7 at the end part of the elastic thin plate 5, and the resultant force of all the elastic thin plates in the quasi-zero stiffness vibration isolator is kept in the vertical direction. The quasi-zero stiffness vibration isolator realizes the quasi-zero stiffness characteristic of the quasi-zero stiffness vibration isolator by utilizing the large bending deformation of the elastic thin plate.

After the elastic thin plate 5 is bent into a U shape, when the bending curvature of the elastic thin plate is changed in a certain range, the force applied by the elastic thin plate to the outer frame and the inner slide block is unchanged, the quasi-zero stiffness vibration isolator integrally shows a larger static bearing capacity, and the dynamic stiffness is 0. When the vibration input member moves downward (as shown in fig. 4 (b)), the bending curvature of the 4 elastic thin plates 5 on the upper side of the inner slider 3 becomes smaller, and the bending curvature of the 4 elastic thin plates 5 on the lower side of the inner slider becomes larger; when the vibration input member moves upward, the bending curvature of the 4 elastic thin plates 5 on the upper side of the inner slider 3 becomes large, and the bending curvature of the 4 elastic thin plates 5 on the lower side of the inner slider becomes small; however, the whole static bearing capacity of the quasi-zero stiffness vibration isolator is kept unchanged, the whole dynamic stiffness of the quasi-zero stiffness vibration isolator is 0, and then the quasi-zero stiffness vibration isolator can effectively isolate vibration from low frequency to high frequency.

As shown in fig. 1 and 2, the vibration input member is an outer frame 4 including a top plate 16, a bottom plate 17, a first side plate 18, and a second side plate 19. The top plate 16 is provided with a first through hole, and the inner surface of the top plate and/or the inner surface of the bottom plate are provided with grooves. The first side plate 18 and the second side plate 19 are each provided with a chute and a through hole. The connecting rod 2 passes through the first through hole and is connected with the inner slide block 3. The two ends of the inner sliding block 3 are respectively installed in the sliding grooves of the first side plate 18 and the second side plate 19, and the inner sliding block 3 can slide along the sliding grooves. The long shaft 6 is clamped in the inner surface groove of the top plate and/or the inner surface groove of the bottom plate, and the end part of the long shaft 6 is rotatably arranged on the through hole. As shown in fig. 4(a) and 4(b), the surface of the inner slide 3 has a groove, and the stub shaft 7 is fitted into the groove of the inner slide 3.

In a preferred embodiment, the upper surface of the inner slide block 3 is provided with a first groove and a second groove which are arranged in parallel, and the lower surface of the inner slide block 3 is provided with a third groove and a fourth groove which are arranged in parallel; the number of the elastic components is eight, and the elastic components are respectively named as a first elastic element 8, a second elastic element 9, a third elastic element 10, a fourth elastic element 11, a fifth elastic element 12, a sixth elastic element 13, a seventh elastic element 14 and an eighth elastic element; the arrangement of the eight elastic members is as follows:

a first elastic element 8, a second elastic element 9, a third elastic element 10 and a fourth elastic element 11 are arranged on the inner slide block 3; the short shafts of the first elastic element 8 and the second elastic element 9 are clamped in the first groove; the long axes of the first elastic element 8 and the second elastic element 9 are both clamped into the fifth groove of the top plate 16, and the ends of the long axes of the first elastic element 8 and the second elastic element 9 are respectively mounted on the second through hole 20 and the third through hole 21 of the first side plate 18 and the second side plate 19; the third elastic element 10 and the fourth elastic element 11 are respectively arranged along the first plane with the first elastic element 8 and the second elastic element 9 symmetrically; the first plane is a longitudinal section of the inner slide block 3, and the longitudinal section is a longitudinal section located at the center of the inner slide block 3; the fifth elastic element 12, the sixth elastic element 13, the seventh elastic element 14 and the eighth elastic element are respectively symmetrical with the first elastic element 8, the second elastic element 9, the third elastic element 10 and the fourth elastic element 11 relative to the inner slide 3.

When the quasi-zero stiffness vibration isolator is provided with a plurality of elastic components, the thickness and/or the length of the elastic thin plate (5) can be adjusted in the actual use process so as to adjust the overall static bearing capacity of the quasi-zero stiffness vibration isolator.

The free state is a state in which the elastic sheet 5 is not yet mounted on the quasi-zero stiffness vibration isolator, and no external force is applied to the elastic sheet 5. The assembled state is a state in which the elastic sheet 5 is mounted on the quasi-zero stiffness vibration isolator and no external force is applied to the quasi-zero stiffness vibration isolator. The working state is a state in which the elastic sheet 5 is mounted on the quasi-zero stiffness vibration isolator and external force is applied to the quasi-zero stiffness vibration isolator.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.