阅读说明：本技术 一种光栅尺 (Grating ruler ) 是由 王洋 李德胜 逄增宝 焦环宇 郎志明 武平 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种光栅尺,包括尺壳和设于其上的读数头,还包括：在尺壳的豁口处设置有用于与读数头的梭形面配合的至少两组密封条；任意一组密封条包括沿尺壳的豁口的两侧相对设置的第一密封条和第二密封条,第一密封条和第二密封条的内侧均分别设有存储槽,存储槽能够和与其相对的第一密封条或第二密封条的头部搭接以实现密封；分别设于尺壳长度方向的两端的密封导流板,密封导流板设于尺壳和端盖之间。该装置通过设置至少两组密封条、存储槽和密封导流板的形式分别对尺壳、读数头和端盖之间的间隙进行密封,提高密封效果,密封保持性高,维护频次低,降低成本,提高生产效率。(The invention discloses a grating ruler, which comprises a ruler shell and a reading head arranged on the ruler shell, and also comprises: at least two groups of sealing strips which are matched with the spindle-shaped surface of the reading head are arranged at the notch of the ruler shell; any group of sealing strips comprises a first sealing strip and a second sealing strip which are oppositely arranged along two sides of the opening of the ruler shell, the inner sides of the first sealing strip and the second sealing strip are respectively provided with a storage groove, and the storage grooves can be lapped with the head parts of the first sealing strip or the second sealing strip which are opposite to the storage grooves to realize sealing; the sealing guide plates are respectively arranged at the two ends of the length direction of the ruler shell and are arranged between the ruler shell and the end cover. The device seals the clearance between chi shell, reading head and the end cover respectively through the form that sets up at least two sets of sealing strip, holding tank and sealed guide plate, improves sealed effect, and sealed retentivity is high, and it is low to maintain the frequency, and reduce cost improves production efficiency.)

1. The utility model provides a grating ruler, includes the chi shell and locates its reading head, its characterized in that still includes:

At least two groups of sealing strips which are matched with the fusiform surface of the reading head are arranged at the notch of the ruler shell;

Any group of sealing strips comprises a first sealing strip and a second sealing strip which are oppositely arranged along two sides of the opening of the ruler shell, the inner sides of the first sealing strip and the second sealing strip are respectively provided with a storage groove, and the storage grooves can be lapped with the head parts of the first sealing strip or the second sealing strip which are opposite to the storage grooves to realize sealing;

And the sealing guide plates are respectively arranged at two ends of the ruler shell in the length direction and are arranged between the ruler shell and the end cover.

2. The grating ruler of claim 1, wherein the inner sides of the first sealing strip and the second sealing strip are respectively provided with a plurality of lubricating grooves for placing lubricating grease; the area of the lubricating grooves is uniformly increased from the head to the tail of the first sealing strip and the head to the tail of the second sealing strip.

3. the grating ruler of claim 2, wherein the sealing guide plate has sealing members respectively laid on both side wall surfaces thereof for sealing with the ruler shell and the end caps, and the sealing members are specifically sealing rubber strips.

4. The grating ruler of claim 3, wherein the sealing guide plate is provided with a yielding groove for yielding the sealing strip protruding from the ruler shell along the length direction.

5. the grating ruler of claim 4, further comprising a mounting groove disposed inside the ruler shell for mounting the sealing baffle, wherein the shape of the mounting groove is adapted to the shape of the sealing baffle.

6. The grating ruler of claim 1, wherein the first sealing strip and the second sealing strip are respectively provided with a mounting protrusion for matching with the sealing strip mounting groove.

7. A grating ruler according to any one of claims 1-6 wherein adjacent sealing strips cooperate with the shuttle-shaped surface to form a vent cavity to which a vent assembly for blowing away dust is connected.

8. The grating ruler of claim 7, wherein the vent assembly comprises:

The vent hole is formed in the outer side of the end cover and communicated with the outside;

the ventilation and flow guide piece is arranged on the inner side of the end cover and is communicated with the vent hole, and the ventilation and flow guide piece comprises a central part communicated with the vent hole and flow guide surfaces which are oppositely arranged along two sides of the central part and guide airflow;

The ventilation guide groove is arranged on one side of the sealing guide plate and used for installing the ventilation guide piece, a guide opening corresponding to the guide surface is formed in the ventilation guide groove, hollow guide columns corresponding to the guide openings one to one are arranged on the other side of the sealing guide plate, and the hollow guide columns are communicated with the ventilation cavity.

9. the grating ruler of claim 8, wherein the venting cavities comprise a first venting cavity and a second venting cavity respectively formed between adjacent first sealing strips and between adjacent second sealing strips, and the hollow flow guiding columns are respectively arranged in the first venting cavity and the second venting cavity.

10. the grating ruler of claim 9, wherein the inner walls of the ruler shells corresponding to the first venting cavity and the second venting cavity are provided with arc surfaces for fitting with the wall surfaces of the hollow flow guiding columns.

Technical Field

The invention relates to the field of precision measurement equipment, in particular to a grating ruler.

Background

The closed grating ruler is a representative product as a linear position measuring device in the field of precision measurement and automatic control, is widely applied to high-precision numerical control machines and high-precision automatic measuring equipment, is particularly used for measuring the relative positions of a cutter and a workpiece to be processed in a processing machine tool, and has high protection level, so that the grating ruler can run safely and reliably for a long time. The high-precision closed grating ruler, the driver, the linear motor and the upper mechanism form a full closed loop, and high-precision measurement is realized.

closed grating chi adopts the individual layer sealing strip structure mostly in the existing market, and the primary structure includes the aluminium alloy shell, and the shell is equipped with the opening in the ascending one side of length direction, and during this opening was arranged in to the individual layer sealing strip for stop in pollutants such as outside dust, greasy dirt, coolant liquid got into the chi shell, prevented to cause the pollution to inside grating, influence sensor signal quality, and then influence measurement accuracy, lead to grating chi reading to report the mistake seriously even, the system is paralysed. Because the material and the structural feature of sealing strip, the circulation action that opens and shuts often in the work, the sealed effect of individual layer sealing strip is limited, and general continuous operation is half a year, just needs professional to change the sealing strip or wipe the maintenance to sealing strip and chi shell inside, causes inconvenience to the application producer like this, and the maintenance cost increases, has influenced the production efficiency of equipment.

Disclosure of Invention

In view of the above, the present invention provides a grating ruler, so as to solve the problems of poor sealing effect, frequent maintenance, increased maintenance cost, etc. of the existing grating ruler single-layer sealing strip.

in order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a grating ruler, includes the chi shell and locates the reading head on it, still includes:

At least two groups of sealing strips which are matched with the fusiform surface of the reading head are arranged at the notch of the ruler shell;

Any group of sealing strips comprises a first sealing strip and a second sealing strip which are oppositely arranged along two sides of the opening of the ruler shell, the inner sides of the first sealing strip and the second sealing strip are respectively provided with a storage groove, and the storage grooves can be lapped with the head parts of the first sealing strip or the second sealing strip which are opposite to the storage grooves to realize sealing;

And the sealing guide plates are respectively arranged at two ends of the ruler shell in the length direction and are arranged between the ruler shell and the end cover.

Preferably, the inner sides of the first sealing strip and the second sealing strip are respectively provided with a plurality of lubricating grooves for placing lubricating grease; the area of the lubricating grooves is uniformly increased from the head to the tail of the first sealing strip and the head to the tail of the second sealing strip.

preferably, the sealing elements used for sealing with the ruler shell and the end covers are respectively paved on two side wall surfaces of the sealing guide plate, and the sealing elements are specifically sealing rubber strips.

Preferably, the sealing guide plate is provided with an abdicating groove for abdicating the sealing strip protruding out of the ruler shell along the length direction.

Preferably, the measuring tape further comprises a mounting groove which is arranged on the inner side of the ruler shell and used for mounting the sealing guide plate, and the shape of the mounting groove is adapted to the shape of the sealing guide plate.

Preferably, locate on the chi shell, be used for respectively right the first sealing strip with the sealing strip mounting groove of second sealing strip installation, first sealing strip with the second sealing strip be equipped with respectively be used for with sealing strip mounting groove complex installation arch.

Preferably adjacent said sealing strip cooperates with the shuttle surface to form a vent chamber to which is connected a vent assembly for blowing away dirt.

preferably, the vent assembly comprises:

the vent hole is formed in the outer side of the end cover and communicated with the outside;

The ventilation and flow guide piece is arranged on the inner side of the end cover and is communicated with the vent hole, and the ventilation and flow guide piece comprises a central part communicated with the vent hole and flow guide surfaces which are oppositely arranged along two sides of the central part and guide airflow;

the ventilation guide groove is arranged on one side of the sealing guide plate and used for installing the ventilation guide piece, a guide opening corresponding to the guide surface is formed in the ventilation guide groove, hollow guide columns corresponding to the guide openings one to one are arranged on the other side of the sealing guide plate, and the hollow guide columns are communicated with the ventilation cavity.

Preferably, the ventilation cavity comprises a first ventilation cavity and a second ventilation cavity which are respectively formed between the adjacent first sealing strips and between the adjacent second sealing strips, and the hollow diversion columns are respectively arranged in the first ventilation cavity and the second ventilation cavity.

Preferably, an arc-shaped surface used for being attached to the wall surface of the hollow flow guide column is arranged on the inner wall of the ruler shell corresponding to the first ventilation cavity and the second ventilation cavity.

The grating ruler provided by the invention comprises a ruler shell and a reading head arranged on the ruler shell, and further comprises: at least two groups of sealing strips which are matched with the spindle-shaped surface of the reading head are arranged at the notch of the ruler shell; any group of sealing strips comprises a first sealing strip and a second sealing strip which are oppositely arranged along two sides of the opening of the ruler shell, the inner sides of the first sealing strip and the second sealing strip are respectively provided with a storage groove, and the storage grooves can be lapped with the head parts of the first sealing strip or the second sealing strip which are opposite to the storage grooves to realize sealing; the sealing guide plates are respectively arranged at the two ends of the length direction of the ruler shell and are arranged between the ruler shell and the end cover.

By applying the grating ruler provided by the invention, at least two groups of sealing strips are arranged to prevent external pollutants such as dust, oil stain and cooling liquid from entering the ruler shell, so that pollution to the grating inside is prevented, the signal quality of a sensor is influenced, the top sealing of the sealing strips is realized by overlapping the head parts of the storage tank and the sealing strips, so that the pollutants are prevented from entering the ruler shell due to the overlarge opening of the sealing strips in a non-reading head contact area, and meanwhile, the sealing guide plate is arranged between the ruler shell and the end cover so as to separate the pollutants between the ruler shell and the end cover, namely, the device seals gaps among the ruler shell, the reading head and the end cover respectively by arranging at least two groups of sealing strips, the storage tank and the sealing guide plate, so that the sealing effect is improved, the sealing retentivity is high.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

fig. 1 is a schematic diagram of an explosion structure of a grating ruler according to an embodiment of the present invention;

FIG. 2 is a schematic view of the partial cross-sectional structure of FIG. 1;

FIG. 3 is a partially enlarged view of the ruler housing according to the embodiment of the present invention;

FIG. 4 is a schematic structural view of a first sealing tape and a second sealing tape according to an embodiment of the present invention;

FIG. 5 is a schematic side view of a ruler case according to an embodiment of the present invention;

Fig. 6 is a schematic structural view of a sealing baffle according to an embodiment of the present invention;

Fig. 7 is a schematic structural diagram of an end cap according to an embodiment of the present invention.

The drawings are numbered as follows:

The device comprises a reading head 1, a sealing strip 2, a scale grating 3, a scale shell 4, a sealing guide plate 5 and an end cover 6;

The sealing device comprises a first sealing strip 21, a second sealing strip 22, a storage groove 23, a lubricating groove 24, a sealing strip mounting groove 41, a sealing element 51, a yielding groove 52, a vent hole 61, a mounting groove 62, a first vent cavity 71, a second vent cavity 72, a vent guide groove 81, a hollow guide column 82, a guide surface 83 and a guide protrusion 84.

Detailed Description

the embodiment of the invention discloses a grating ruler, which aims to solve the problems that the existing grating ruler is poor in single-layer sealing strip sealing effect, needs frequent maintenance, increases maintenance cost and the like.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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 invention.

Referring to fig. 1-7, fig. 1 is a schematic diagram illustrating an explosion structure of a grating ruler according to an embodiment of the present invention; FIG. 2 is a schematic view of the partial cross-sectional structure of FIG. 1; FIG. 3 is a partially enlarged view of the ruler housing according to the embodiment of the present invention; FIG. 4 is a schematic structural view of a first sealing tape and a second sealing tape according to an embodiment of the present invention; FIG. 5 is a schematic side view of a ruler case according to an embodiment of the present invention; fig. 6 is a schematic structural view of a sealing baffle according to an embodiment of the present invention; fig. 7 is a schematic structural diagram of an end cap according to an embodiment of the present invention.

in a specific implementation mode, the grating ruler provided by the present invention includes a ruler shell 4 and a reading head 1 disposed thereon, the reading head 1 is disposed above the ruler shell 4, the reading head 1 is disposed at a gap of the ruler shell 4, and two ends of the ruler shell 4 are detachably and fixedly connected with an end cover 6, wherein the connection and fixing modes of the reading head 1 and the ruler shell 4, and the end cover 6 and the ruler shell 4 can refer to the prior art, and further includes:

At least two groups of sealing strips 2 which are matched with the fusiform surface of the reading head 1 are arranged at the notch of the ruler shell 4; at least two groups comprise two or more groups, the two groups of sealing strips 2 are arranged in parallel, the preferred distances are equal, the at least two groups of sealing strips 2 are arranged at the notch of the ruler shell 4 to realize multilayer protection of the ruler shell 4, the pollution of the ruler grating 3 and other sensing devices in the ruler shell 4 is reduced, the protection effect is obvious, meanwhile, the ruler shell 4 and the sealing strips 2 can be fixed in a bonding or clamping mode, and the sealing strips can be arranged according to actual requirements and are all in the protection range of the invention.

Any group of sealing strips 2 comprises a first sealing strip 21 and a second sealing strip 22 which are oppositely arranged along two sides of the opening of the ruler shell 4, the inner sides of the first sealing strip 21 and the second sealing strip 22 are respectively provided with a storage groove 23, and the storage groove 23 can be lapped with the head part of the first sealing strip 21 or the second sealing strip 22 opposite to the storage groove 23 to realize sealing; it will be appreciated that the contact area of the shuttle face with the tape case 4 comprises a reading head 1 contact area and a non-reading head 1 contact area, and is arranged to ensure sealing between the first sealing strip 21 and the second sealing strip 22 in the non-reading head 1 contact area, wherein the storage groove 23 provided in one of the first sealing strip 21 and the second sealing strip 22 overlaps with the head of the other to achieve sealing, and the head is placed in the storage groove 23 to seal the two, such as the storage groove 23 of the first sealing strip 21 overlaps with the head of the second sealing strip 22, which is only a preferred embodiment. Wherein, the preferred arc wall of holding tank 23 to guarantee the butt joint effect of contact, simultaneously, the head generally is arc portion, guarantees the overlap joint effect through arc wall and arc portion cooperation, when reading head 1 slided to contact with sealing strip 2, can realize the separation fast, guarantees with reading head 1's cooperation. In other embodiments, the specific form of the storage tank 23 may be set as needed, as long as the same technical effect can be achieved, and the specific implementation manner is not limited.

The first sealing strips 21 and the second sealing strips 22 are oppositely arranged along two sides of the opening respectively, preset distances are arranged among the groups of first sealing strips 21, and similarly, preset distances are also arranged among the groups of second sealing strips 22.

And the sealing guide plates 5 are respectively arranged at two ends of the ruler shell 4 in the length direction, and the sealing guide plates 5 are arranged between the ruler shell 4 and the end cover 6. From this setting to guarantee the sealed effect between chi shell 4 and the end cover 6, in an embodiment, can set up the embedded groove of the sealed guide plate 5 of embedding on end cover 6, realize the installation and seal through sealed glue, and accessible bolt spare end cover 6 is fixed with chi shell 4, and then realizes three's fixed.

By applying the grating ruler provided by the invention, at least two groups of sealing strips 2 are arranged to prevent external pollutants such as dust, oil stain and cooling liquid from entering the ruler shell 4, prevent the pollution to the internal grating and influence the signal quality of the sensor, and the top sealing of the sealing strip 2 is realized by overlapping the storage tank 23 and the head part of the sealing strip 2, so that the phenomenon that the opening of the sealing strip 2 at the contact area of the non-reading head 1 is too large to cause the entry of pollutants is prevented, meanwhile, a sealing guide plate 5 is arranged between the ruler shell 4 and the end cover 6 to realize the separation of pollutants between the ruler shell and the end cover, namely, the device seals the clearance between chi shell 4, reading head 1 and the end cover 6 respectively through the form that sets up at least two sets of sealing strip 2, holding tank 23 and sealed guide plate 5, improves sealed effect, and sealed retentivity is high, and the maintenance frequency is low, and reduce cost improves production efficiency.

specifically, the inner sides of the first sealing strip 21 and the second sealing strip 22 are respectively provided with a plurality of lubricating grooves 24 for placing lubricating grease, and the number of the lubricating grooves 24 is multiple. The lubricating groove 24 and the storage groove 23 are arranged in the same direction, and preferably have the same shape and structure, so that the production and the processing are convenient, the lubricating groove 24 is used for storing lubricating grease, the friction force between the sealing strip 2 and the reading head 1 in relative motion is reduced, the service life of the sealing strip 2 is prolonged, and the dragging force during the work is reduced. The plurality of lubricating grooves includes two or more, in one embodiment, the number of the lubricating grooves 24 is preferably two, and in other embodiments, the number of the lubricating grooves 24 can be set according to actual needs, which is within the protection scope of the present invention.

further, the areas of the plurality of lubrication grooves 24 each increase in order from the head to the tail of the first seal strip 21 and the second seal strip 22, respectively. From this setting to guarantee the open-ended size in the upper portion of sealing strip 2, in order to guarantee the leakproofness of sealing strip 2 head from this, keeping away from first sealing strip 21 and second sealing strip 22 gap one end, can set up the lubrication groove 24 of great area in order to bear more lubricating grease at the afterbody, guarantee lubricated effect under the prerequisite of the leakproofness of guaranteeing first sealing strip 21 and second sealing strip 22.

in one embodiment, the sealing deflector 5 is laid with sealing elements 51 on two side wall surfaces for sealing with the ruler shell 4 and the end cover 6, respectively, and the sealing elements 51 are sealing rubber strips. Be equipped with sealing member 51 on sealed guide plate 5's the two walls, paste tight sealedly with end cover 6 through the soft round of sealing rubber strip of matter of moulding plastics on sealed guide plate 5, the another side is pasted tightly through the sealed rubber strip of moulding plastics and the cooperation of chi shell 4 side, furtherly, with end cover 6 through sealing bolt, sealed guide plate 5 and the fastening of chi shell 4, the accessible sets up the counter bore on end cover 6 during the sealing bolt fastening, seal through setting up the sealing washer in counter bore department, also can paint special sealed glue or complex counter bore and sealed cap through the conical surface laminating in screw thread department, play the sealed effect of screw location.

specifically, the sealing guide plate 5 is provided with an abdicating groove 52 for abdicating the sealing strip 2 protruding from the ruler shell 4 along the length direction. The shape of the abdicating groove 52 is the same as the cross section shape of the sealing strip 2, the sealing strip 2 protrudes from the end surface part of the ruler shell 4 and is arranged in the abdicating groove 52 to prevent the contaminant from entering into the sealing strip 2 from the gap between the end cover 6 and the ruler shell 4, in a preferred embodiment, the sealing strips 2 are two groups, and correspondingly, the ruler shell 4 is provided with abdicating grooves 52 corresponding to the two groups of sealing strips 2.

Further, the air-tight ruler also comprises an installation groove 62 which is arranged on the inner side of the ruler shell 4 and used for installing the air-tight guide plate 5, and the shape of the installation groove 62 is adapted to the shape of the air-tight guide plate 5. The sealing guide plate 5 is embedded into the ruler shell 4 through the mounting groove 62, sealing with the ruler shell 4 is achieved through the sealing rubber strips arranged in the circumferential direction of the sealing guide plate 5, and a counter bore used for bolt sealing and fixing is formed in the end cover 6.

In one embodiment, the sealing strip mounting grooves 41 are formed in the tape housing 4 and used for mounting the first sealing strip 21 and the second sealing strip 22 respectively, and the first sealing strip 21 and the second sealing strip 22 are provided with mounting protrusions matched with the sealing strip mounting grooves 41 respectively. The both ends of the opening department of chi shell 4 are equipped with sealing strip mounting groove 41, and the installation location of first sealing strip 21 and second sealing strip 22 is realized with the protruding cooperation of installation to sealing strip mounting groove 41, realizes fixedly through the mode of joint, and sealing strip mounting groove 41 and the protruding preferred rectangle of installation also can set up corresponding structure as required in other embodiments, as long as can reach the same technological effect can.

On the basis of the above embodiments, the adjacent sealing strip 2 cooperates with the shuttle surface to form a ventilation chamber, to which a ventilation assembly for blowing away dust is connected. It can be understood that the ventilation assembly is connected with an air source, the adjacent sealing strip 2 and the shuttle-shaped surface form a closed ventilation cavity, the ventilation cavity is connected with the ventilation assembly, the ventilation assembly can be specifically a ventilation pipeline communicated with the end cover 6, air flow contacts with the shuttle-shaped surface along the adjacent sealing strip 2 in the ventilation cavity, wherein a first ventilation cavity 71 is formed between the adjacent first sealing strip 21 and the shuttle-shaped surface, a second ventilation cavity 72 is formed between the adjacent second sealing strip 22 and the shuttle-shaped surface, the air flow is respectively led into the first ventilation cavity 71 and the second ventilation cavity 72 to form negative pressure in the two cavities, and one side presses the inner sealing strip 2 in the ruler shell 4, so that the attaching force of the inner sealing strip 2 is increased, and the protection is enhanced. And on the other hand, the outer sealing strip 2 is outwards propped against the outer sealing strip, compressed air is outwards and continuously blown out through the gap of the outer sealing strip 2, the pollutants are prevented from entering from outside to inside, and the pollutants are prevented from entering through the multilayer sealing strips 2 and a method of communicating the compressed air between the layers.

Further, a vent hole 61 which is arranged outside the end cover 6 and communicated with the outside;

The ventilation and flow guide piece is arranged on the inner side of the end cover 6 and communicated with the vent hole 61, and comprises a central part communicated with the vent hole 61 and flow guide surfaces 83 which are oppositely arranged along two sides of the central part and guide airflow;

the ventilation guide groove 81 is arranged on one side of the sealing guide plate 5 and used for installing a ventilation guide piece, a guide opening corresponding to the guide surface 83 is formed in the ventilation guide groove 81, hollow guide columns 82 corresponding to the guide openings one to one are arranged on the other side of the sealing guide plate 5, and the hollow guide columns 82 are communicated with the ventilation cavity.

The number of the vent holes 61 is preferably one, the vent holes 61 penetrate through the end cover 6 to realize air circulation, the central portion of the ventilation and flow guide member is communicated with the vent holes 61, flow guide surfaces 83 are arranged on two sides of the central portion to divide air into two flows, a flow guide protrusion 8484 convenient for air convergence is arranged between the central portion and the flow guide surfaces 83, the flow guide surfaces 83 are symmetrically arranged along two sides of the central portion, the flow guide surfaces 83 incline inwards from the central portion to the edges to leave a channel for guiding air flow, and the air flow is divided into two flows along the flow guide surfaces 83 after passing through the central portion.

one side of sealed guide plate 5 is equipped with the guiding gutter 81 of ventilating, its position and degree of depth suit with the water conservancy diversion spare of ventilating, be equipped with the water conservancy diversion mouth in the guiding gutter 81 of ventilating, the water conservancy diversion mouth is leading-in to the chamber of ventilating with the air current, the air current enters into cavity water conservancy diversion post 82 through the water conservancy diversion mouth, realize that the air current is by outside to ventilating switching on in the chamber, first chamber 71 and second chamber 72 of ventilating correspond respectively has cavity water conservancy diversion post 82, wherein, cavity water conservancy diversion post 82 and sealed guide plate 5 fixed connection, preferably integral type setting, the front end of water conservancy diversion post is equipped with the fillet.

specifically, the vent cavity comprises a first vent cavity 71 and a second vent cavity 72 which are respectively formed between adjacent first sealing strips 21 and adjacent second sealing strips 22, and hollow flow guide columns 82 are respectively arranged in the first vent cavity 71 and the second vent cavity 72.

The first ventilation cavity 71 and the second ventilation cavity 72 are separated by a fusiform surface, the hollow flow guide column 82 is respectively communicated with the first ventilation cavity 71 and the second ventilation cavity 72 to realize air flow introduction, and the hollow flow guide column 82 is provided with a preset length which can be set according to requirements.

Further, an arc-shaped surface for being attached to the wall surface of the hollow diversion column 82 is arranged on the inner wall of the ruler shell 4 corresponding to the first ventilation cavity 71 and the second ventilation cavity 72. The hollow flow guiding column 82 is preferably a cylinder, the arc-shaped surface indirectly supports the hollow flow guiding column 82 to prevent the hollow flow guiding column 82 from being bent when the length is too long, and the hollow flow guiding column 82 is in contact with the ventilation cavity to interfere with the movement of the reading head 1, meanwhile, the hollow flow guiding column 82 is attached to the arc-shaped surface to optimize the installation space and ensure the air flow circulation, and preferably, an adhesive can be arranged between the arc-shaped surface and the hollow flow guiding column 82 to fix the hollow flow guiding column, or when the arc-shaped surface can effectively support the hollow flow guiding column 82, the arrangement is not performed, and the arrangement is within the protection scope of the invention. In other embodiments, when the hollow guide pillar 82 is not a cylinder, a groove may be correspondingly disposed on the inner wall of the ruler shell 4 to mount and position the hollow guide pillar 82.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be 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 embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. 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 invention. Thus, the present invention 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.