CN219133642U

CN219133642U - Print carriage

Info

Publication number: CN219133642U
Application number: CN202223535351.1U
Authority: CN
Inventors: 张法妞; 王纪忠; 鲁显胜
Original assignee: Henan Yindu Digital Technology Co ltd
Current assignee: Henan Yindu Digital Technology Co ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-06-06
Anticipated expiration: 2032-12-29

Abstract

A print trolley comprises a traversing assembly, a spray head assembly and a lifting assembly connected between the traversing assembly and the spray head assembly; a servo motor fixedly connected with the transverse moving assembly drives a transmission screw rod to drive the lifting block to lift; because the transmission screw rod and the lifting block are screw rod nut transmission, the lifting precision of the spray head assembly can be effectively ensured; the lifting block and the spray head component are inserted through the insertion strip, so that the installation is simple and convenient; in addition, the lifting guide rail fixedly connected with the transverse moving assembly is vertically matched with the lifting slide block in a sliding manner, so that the distance between the nozzle assembly and the transverse moving assembly is kept while the nozzle assembly is guided along with lifting of the lifting block; therefore, the height of the printing trolley can be adjusted electrically through the servo motor to replace manual adjustment, so that the manual uncertainty is reduced, and the adjustment effect is guaranteed.

Description

Print carriage

Technical Field

The utility model relates to the technical field of ink-jet printing, in particular to a printing trolley.

Background

Inkjet printing is the most widely used printing technique; the core component of a printer applying ink jet printing is a print carriage; in the inkjet printing, a printing trolley transversely moves, and a nozzle at the bottom of the printing trolley performs inkjet; the thickness of the printing material is different, and the actual required height of the bottom surface of the printing trolley is also different; the existing height adjustment of the printing trolley is that before printing, the height is manually adjusted to control the distance between the printing spray head and the underlying printing stock, the ink-jet effect is ensured by controlling the distance, and the printing picture quality is ensured; the manual adjustment process in the prior art is complicated, and an experienced master is required to adjust accurately; it is therefore necessary to provide a print carriage capable of electrically adjusting the height of the ejection head, thereby realizing automation and precision of the adjustment process.

Disclosure of Invention

The utility model aims to solve the problems and provides a printing trolley.

The technical scheme of the utility model is as follows: a print trolley comprises a traversing assembly, a spray head assembly and a lifting assembly connected between the traversing assembly and the spray head assembly;

the transverse moving assembly comprises a transverse moving plate which is vertically arranged, and clamping strap mechanisms which are arranged on two sides of the back of the transverse moving plate and are connected with the end parts of the synchronous belt; the synchronous belt refers to a trolley driving synchronous belt on the printer, and two synchronous ends are respectively connected to the entrainment mechanism. Realize the driving of the transverse reciprocating motion of the trolley.

The lifting assembly comprises a lifting driving structure arranged in the middle of the transverse moving plate and parallel guide mechanisms arranged on two sides, the guide mechanisms are in the form of sliding rails and sliding sleeves, and the details will be described later, the lifting driving mechanism comprises a servo motor arranged on the upper part of the transverse moving plate, a transmission screw connected to an output shaft at the lower end of the servo motor, and a lifting block sleeved on the transmission screw through threads, two sides of the lifting block are provided with inserting notches, and a rotary handle is arranged on an upper output shaft of the servo motor;

the spray head assembly comprises a mounting plate vertically arranged and connected with the lifting block, and a spray head seat plate horizontally arranged and vertically connected with the lower edge of the mounting plate, a plurality of spray heads are arranged on the spray head seat plate, and the spray heads are arranged according to the number and layout modes of the printers; the middle part of the mounting plate is provided with a through hole which is transversely penetrated, an insertion strip transversely penetrates through the through hole, and the inner end of the insertion strip is in insertion fit with an insertion notch of the lifting slide block, so that the lifting block can drive the insertion strip to further drive the mounting plate to move up and down under the driving of the screw rod; the guide mechanism is connected between the transverse moving plate and the mounting plate.

Preferably, the nozzle seat plate is provided with a height measurement through hole, and the nozzle seat plate at the upper part of the hole is provided with a height measurement device; the height measuring device comprises a vertically arranged telescopic electromagnet and an external contact travel switch, wherein an electromagnet shell is fixed on a spray head seat plate through a frame, a switch touch block body and a probe body are connected to the lower end of a vertical telescopic armature telescopic rod in the middle of the electromagnet, the lower end of the probe body penetrates through the height measuring through hole, an L-shaped pressing plate is mounted on the side face of the switch touch block body, the pressing plate is mounted on the side face of the switch touch block body through a vertical long round hole, a support of the contact travel switch is mounted on the frame, the contact travel switch is fixed on the support, and the contact travel switch is located under the pressing plate.

Preferably, the guide mechanism comprises vertical guide rails fixedly connected to two sides of the transverse moving plate and vertical sliding sleeves fixedly connected to corresponding positions on two sides of the mounting plate, the sliding sleeves are sleeved on the vertical guide rails to form vertical sliding pairs, and the movement directions of the two sliding pairs are parallel to the movement direction of the lifting block. Of course, the installation positions of the guide rail and the sliding sleeve can be exchanged, and the operation of the sliding pair is not influenced.

Preferably, the two inserting strips are symmetrically distributed on two sides of the lifting block, the front ends of the two inserting strips are connected into a whole through the connecting plate, so that the inserting strips and the connecting plate form a U-shaped transverse fork component, and the connecting plate is connected with the mounting plate through screws.

Preferably, the upper end and the lower end of the transmission screw are respectively sleeved with a bearing box, the bearing boxes are fixed on the transverse moving plate through screws, and the transmission screw is connected with the lower output shaft of the servo motor through a coupling, so that the problem of unstable transmission caused by installation of different axial errors between the servo motor and the transmission screw can be solved.

Preferably, the mounting panel and the symmetrical fixedly connected with end plate in shower nozzle bedplate both ends, the tip can consolidate the right angle overall arrangement of mounting panel and shower nozzle bedplate, the lateral surface of every end plate is hung and is equipped with lower open-ended outer storehouse cover, is equipped with the UV lamp and the static stick that destatics of shining downwards in outer storehouse cover, UV lamp and static stick that destatics all install on the lateral surface of end plate through the bracket.

Preferably, the lateral surface of every outer storehouse cover be equipped with buffer stop, this buffer stop is including the fixed grillage of laminating outer storehouse cover installation and the swing board of articulated on fixed grillage, the both ends of fixed grillage transversely stretch out and have two symmetrical support otic placodes, the both ends of swing board are equipped with the articulated otic placode of transversely stretching out the symmetry, articulated otic placode passes through the articulated shaft and is connected with support otic placode, be equipped with the limit baffle that transversely stretches out in the upper middle part of fixed grillage, the upper end of swing board transversely stretches out and has the apron on the whole length of cover, the apron is located limit baffle upper portion, hang between apron and the fixed splint lower part and be equipped with reset spring, transversely stretch out the touch switch in the fixed splint lower part is installed, touch switch is located the lower part inboard of swing board.

Preferably, the clamping mechanism comprises clamping bottom plates symmetrically arranged at two side edges of the back of the transverse plate and toothed pressing plates fixed on the clamping bottom plates through screws, and positioning grooves are formed in the middle of the clamping bottom plates.

The beneficial effects of the utility model are as follows: the print trolley has the following beneficial effects:

(1) The utility model connects the spray head component and the transverse moving component through the lifting block; a servo motor fixedly connected with the transverse moving assembly drives a transmission screw rod to drive the lifting block to lift; because the transmission screw rod and the lifting block are screw rod nut transmission, the lifting precision of the spray head assembly can be effectively ensured; the lifting block and the spray head component are inserted through the insertion strip, so that the installation is simple and convenient; in addition, the lifting guide rail fixedly connected with the transverse moving assembly is vertically matched with the lifting slide block in a sliding manner, so that the distance between the nozzle assembly and the transverse moving assembly is kept while the nozzle assembly is guided along with lifting of the lifting block; therefore, the height of the printing trolley can be adjusted electrically through the servo motor to replace manual adjustment, so that the manual uncertainty is reduced, and the adjustment effect is guaranteed.

(2) The utility model is also provided with the height measuring device which is linked with the servo motor, the distance between the spray head and the surface of the printing material is judged by the height measuring device, and a basis is provided for the servo motor to adjust the height of the spray head, so that the height adjustment of the spray head of the printing trolley can also realize further automatic adjustment.

(3) The UV lamp and the static eliminating rod are arranged on the two sides of the printing trolley, and are respectively used for solidifying ink and eliminating static electricity, so that printing quality is ensured.

(4) And anti-collision devices are further arranged at two ends of the printing trolley, so that anti-collision protection of the spray heads, the UV lamps and the static removing rods of the printing trolley is realized.

Drawings

Fig. 1 is a schematic diagram of a front view of a carriage in the first embodiment;

FIG. 2 is a schematic view of the sectional structure B-B in FIG. 1;

fig. 3 is one of schematic perspective views of a print carriage in the first embodiment;

FIG. 4 is a second perspective view of the carriage according to the first embodiment;

FIG. 5 is a schematic perspective view of a portion of the components of the traversing plate and lifting assembly of FIG. 1;

FIG. 6 is a schematic diagram of a front view of a portion of the components of the showerhead assembly and the lift assembly;

FIG. 7 is a schematic view of the cross-sectional structure A-A of FIG. 6 and a partial enlarged view thereof;

FIG. 8 is a schematic perspective view of parts of the showerhead assembly and the lift assembly;

FIG. 9 is a schematic perspective view of the height measurement device;

FIG. 10 is a schematic view of a front view of a bump guard;

FIG. 11 is a schematic view of the sectional B-B structure of FIG. 10

FIG. 12 is a schematic perspective view of a bump guard;

FIG. 13 is a schematic perspective view of FIG. 12 with the wobble plate removed;

FIG. 14 is a schematic perspective view of the swing plate of FIG. 12;

FIG. 15 is a schematic perspective view of an insert strip and a connecting plate;

in the figure: 111. traversing plate, 112, entrainment mechanism, 1121, toothed pressure plate, 1122, entrainment base, 1123, positioning slot, 121, servo motor, 1211, rotary handle, 122, drive screw, 1221, bearing cartridge, 1222, coupling, 123, lifting block, 1231, cartridge notch, 124, vertical guide rail, 125, sliding sleeve, 126, insert bar, 1261, connecting plate, 131, mounting plate, 132, shower head seat plate, 133, shower head, 134, height measuring device, 1321, height measuring through hole, 135, end plate, 136, outer housing, 137, anti-collision device, 138, UV lamp, 1381, bracket, 139, static eliminating stick.

1341. Electromagnet 1342, contact travel switch 1343, armature telescopic rod 1345, switch bump block 1346, probe body 1347, pressing plate 1348, adjusting oblong hole 1349, rack 1340 and support;

1371. the hinge assembly comprises fixing plate frames, 1372, swinging plates, 1373, supporting lug plates, 1374, hinge lug plates, 1375, hinge shafts, 1376, limit baffles, 1377, cover plates, 1378, return springs and 1379 and a touch switch.

Detailed Description

Embodiment one: referring to FIGS. 1-15, a print carriage is shown comprising a traversing assembly, a spray head assembly, and a lift assembly coupled between the traversing assembly and the spray head assembly;

the transverse moving assembly comprises a transverse moving plate which is vertically arranged, and clamping strap mechanisms which are arranged on two sides of the back of the transverse moving plate and are connected with the end parts of the synchronous belt; the entraining mechanism is used for being connected with the end part of the synchronous belt for driving the trolley to transversely move, so that the trolley can transversely reciprocate on the guide rail, and the coverage of a printing breadth with a certain width can be realized.

The lifting assembly comprises a lifting driving structure arranged in the middle of the transverse moving plate and parallel guide mechanisms positioned at two sides, the lifting driving mechanism comprises a servo motor positioned at the upper part of the transverse moving plate, a transmission screw rod connected to an output shaft at the lower end of the servo motor, and a lifting block sleeved on the transmission screw rod through threads, two sides of the lifting block are provided with inserting gaps, and a rotary handle is arranged on an upper output shaft of the servo motor; the rotary handle is used for emergency adjustment in the case of failure of the servo motor.

The spray head assembly comprises a mounting plate vertically arranged and connected with the lifting block, and a spray head seat plate horizontally arranged and vertically connected with the lower edge of the mounting plate, and a plurality of spray heads are arranged on the spray head seat plate; the middle part of the mounting plate is provided with a through hole which is transversely penetrated, an insertion strip transversely penetrates through the through hole, the inner end of the insertion strip is in insertion fit with an insertion notch of the lifting slide block, and the guide mechanism is connected between the transverse moving plate and the mounting plate. The lifting assembly drives the screw rod to drive the lifting block to adjust up and down through the servo motor, and the lifting block drives the lifting of the spray head assembly, so that lifting adjustment of the spray head is realized, the servo motor runs and has closed-loop control, the height adjustment of the spray head from the surface of the printing material is more accurate, and the dependence of most manual adjustment is reduced. Compared with the original manual adjustment, the automatic adjustment device can realize electric control adjustment, improves the automation degree, and can also combine other sensors to realize automatic adjustment control.

The spray head seat plate is provided with a height measurement through hole, and a height measurement device is arranged on the spray head seat plate at the upper part of the hole; the height measuring device comprises a vertically arranged telescopic electromagnet and an external contact travel switch, wherein an electromagnet shell is fixed on a spray head seat plate through a frame, the lower end of a vertical telescopic armature telescopic rod in the middle of the electromagnet is connected with a switch bump block and a probe body, the lower end of the probe body penetrates through the height measuring through hole, an L-shaped pressing plate is arranged on the side surface of the switch bump block, the pressing plate is arranged on the side surface of the switch bump block through a vertical long round hole for adjusting the installation height of the pressing plate, the distance between the pressing plate and a lower die contact travel switch is adjusted, and accordingly the length of the probe body extending out of the height measuring through hole is further adjusted, and finally the distance control between the spray head and the surface of a printing material can be determined. A support of a contact travel switch is arranged on the frame, the contact travel switch is fixed on the support, and the contact travel switch is positioned right below the pressing plate. The probe body and the pressing plate of the height measuring device synchronously move downwards under the driving of the armature after the electromagnet is electrified, the probe body extends out of the height measuring through hole on the spray head seat plate, the electromagnet is powered by the pressing plate after being contacted with the contact travel switch, the armature is in a downward extending state with the probe body, then the height measuring device descends along with the spray head seat plate under the driving of the lifting assembly, after the lower end of the probe body is contacted with the surface of a printing material, the probe body and the armature are pushed to generate retraction action, the pressing plate is separated from the contact travel switch, the contact travel switch gives a power-off signal, a control system of the printer stops the operation of a servo motor in the lifting assembly according to the power-off signal, and the operation of the lifting assembly can be controlled according to the signal of the height measuring device, so that the lifting assembly can quantitatively and automatically adjust the distance between the spray head and the surface of the printing material.

The guide mechanism comprises vertical guide rails fixedly connected to two sides of the transverse moving plate and vertical sliding sleeves fixedly connected to corresponding positions on two sides of the mounting plate, the sliding sleeves are sleeved on the vertical guide rails to form vertical sliding pairs, and the movement directions of the two sliding pairs are parallel to the movement direction of the lifting block.

The two inserting strips are symmetrically distributed on two sides of the lifting block, the front ends of the two inserting strips are connected into a whole through the connecting plate, and the connecting plate is connected with the mounting plate through screws. The lifting block moves the mounting plate to rise through the two insertion strips, so that the operation is more stable, and the bearing of the lifting block is more balanced.

The upper end and the lower end of the transmission screw rod are sleeved with bearing boxes, and the bearing boxes are fixed on the transverse moving plate through screws.

The utility model discloses a shower nozzle, including mounting panel, shower nozzle bedplate, mounting panel and shower nozzle bedplate both ends symmetry fixedly connected with end plate, the lateral surface of every end plate is hung and is equipped with lower open-ended outer storehouse cover, is equipped with the UV lamp and the static-removing stick that shines downwards in outer storehouse cover, UV lamp and static-removing stick all install on the lateral surface of end plate through the bracket. UV lamps are used to cure the ink on the surface of the printing material as soon as possible. The problem that the quality of printed patterns is affected by infiltration due to long-term non-drying of the ink is avoided. The static eliminating rod is used for carrying away static electricity on the surface of the printing material, so that the printing quality problem caused by static electricity is avoided.

The lateral surface of every outer storehouse cover be equipped with buffer stop, this buffer stop is including the fixed grillage of laminating outer storehouse cover installation and the swing board of articulated on the fixed grillage, the both ends of fixed grillage transversely stretch out and have two symmetrical support otic placodes, the both ends of swing board are equipped with the articulated otic placode that transversely stretches out the symmetry, articulated otic placode passes through the articulated shaft and is connected with support otic placode, be equipped with the limit baffle that transversely stretches out in the upper middle part of fixed grillage, the upper end of swing board transversely stretches out and has the apron on the whole length of coverage, the apron is located limit baffle upper portion, hang between apron and the fixed splint lower part and have reset spring, the touch switch that transversely stretches out is installed at the fixed splint lower part, touch switch is located the lower part inboard of swing board. When the dolly is moving transversely, once there is the barrier on the printing material surface or print platform's surface, this buffer stop's swing board will contact this barrier, and swing board lower part is at this moment around the inside swing of articulated shaft under the drive of external force, oppression inside after the swing touch the switch and send signal suggestion, the control system of printer stops the synchronous motion of drive of dolly according to this signal, stops the sideslip action of dolly, avoids the barrier to cause destruction to shower nozzle, UV lamp and the static stick etc. of dolly lower part.

The clamping mechanism comprises clamping bottom plates symmetrically arranged at two side edges of the back surface of the transverse plate and toothed pressing plates fixed on the clamping bottom plates through screws, and positioning grooves are formed in the middle of the clamping bottom plates. The toothed pressing plate can clamp the end part of the synchronous belt more tightly, so that the end part of the synchronous belt is prevented from falling off in the operation process, the width of the positioning belt groove is the same as that of the end part of the synchronous belt, the end heads of the synchronous belt on two sides of the trolley are positioned on the same straight line after the trolley is installed, the tensile forces on the two sides are also positioned on the same straight line, and the trolley inclination caused by installation deviation is avoided.

The working process of the print trolley comprises the following steps:

after the printing trolley is mounted on a transverse guide rail of a printer, two ends of a synchronous belt driving the printing trolley to transversely move are fixedly connected through an entrainment mechanism; when a certain printing material is placed on a printing platform of the printer, the synchronous belt drives the printing trolley to transversely move to the upper side of the printing material, an electromagnet in the height measuring device is electrified, an armature of the electromagnet drives the pressing plate and the probe body to move downwards, the probe body protrudes out of the height measuring through hole and then protrudes out of the lower surface of the spray head seat plate, the pressing plate presses on the contact travel switch, and the switch is kept electrified; the control system of the printer starts a servo motor in the lifting assembly to rotate according to the power-on signal, drives a screw rod to rotate, and drives the lifting block and the spray head assembly to move downwards together, at the moment, the spray head moves downwards along with the spray head seat plate, after the probe body contacts the surface of the underlying printing material in the descending process, the probe body is pushed to retract against the electromagnetic force of the armature, the pressing plate is driven to move upwards, the pressing plate is separated from the contact travel switch, the printing control system stops the servo motor according to the power-off signal, so that the servo motor is not rotated any more, the spray head assembly does not move downwards any more, at the moment, the distance between the spray head and the surface of the pressure-bearing material is a proper distance, and the quantifiable and automatic adjustment of the spray head is completed.

After the lifting adjustment of the spray heads is finished, the transverse moving plate of the trolley moves transversely and reciprocally on the transverse guide rail of the printer along with the driving of the synchronous belt, so that the coverage of a printing area is realized, the spray heads on the trolley spray out ink to the surface of a printing material according to program control in the transverse moving process, and printing is realized, at the moment, the UV lamps on two sides of the end part irradiate the ink on the surface of the printing material, so that the ink is quickly solidified, the pattern quality is prevented from being affected by infiltration, static electricity generated on the surface is treated by the static electricity removing rod, and other problems caused by the accumulation of the static electricity are avoided.

Once foreign matters appear on the upper surface of a printing material or on a printing platform, anti-collision devices at two side ends of the printing trolley are contacted with the printing trolley firstly, and the internal touch switch is extruded to give out a touch power-on signal, and a control system of the printer stops the operation of the synchronous belt according to the signal to stop the transverse movement of the printing trolley, so that the parts such as a spray head, a UV lamp, a static removing rod and the like on the trolley are prevented from being damaged by the foreign matters, and the trolley is subjected to anti-collision protection.

Claims

1. A print trolley comprises a traversing assembly, a spray head assembly and a lifting assembly connected between the traversing assembly and the spray head assembly; it is characterized in that the method comprises the steps of,

the transverse moving assembly comprises a transverse moving plate which is vertically arranged, and clamping strap mechanisms which are arranged on two sides of the back of the transverse moving plate and are connected with the end parts of the synchronous belt;

the lifting assembly comprises a lifting driving structure arranged in the middle of the transverse moving plate and parallel guide mechanisms positioned at two sides, the lifting driving mechanism comprises a servo motor positioned at the upper part of the transverse moving plate, a transmission screw rod connected to an output shaft at the lower end of the servo motor, and a lifting block sleeved on the transmission screw rod through threads, two sides of the lifting block are provided with inserting gaps, and a rotary handle is arranged on an upper output shaft of the servo motor;

the spray head assembly comprises a mounting plate vertically arranged and connected with the lifting block, and a spray head seat plate horizontally arranged and vertically connected with the lower edge of the mounting plate, and a plurality of spray heads are arranged on the spray head seat plate; the middle part of the mounting plate is provided with a through hole which is transversely penetrated, an insertion strip transversely penetrates through the through hole, the inner end of the insertion strip is in insertion fit with an insertion notch of the lifting slide block, and the guide mechanism is connected between the transverse moving plate and the mounting plate.

2. The print carriage of claim 1, wherein: the spray head seat plate is provided with a height measurement through hole, and a height measurement device is arranged on the spray head seat plate at the upper part of the hole; the height measuring device comprises a vertically arranged telescopic electromagnet and an external contact travel switch, wherein an electromagnet shell is fixed on a spray head seat plate through a frame, a switch touch block body and a probe body are connected to the lower end of a vertical telescopic armature telescopic rod in the middle of the electromagnet, the lower end of the probe body penetrates through the height measuring through hole, an L-shaped pressing plate is mounted on the side face of the switch touch block body, the pressing plate is mounted on the side face of the switch touch block body through a vertical long round hole, a support of the contact travel switch is mounted on the frame, the contact travel switch is fixed on the support, and the contact travel switch is located under the pressing plate.

3. The print carriage of claim 1, wherein: the guide mechanism comprises vertical guide rails fixedly connected to two sides of the transverse moving plate and vertical sliding sleeves fixedly connected to corresponding positions on two sides of the mounting plate, the sliding sleeves are sleeved on the vertical guide rails to form vertical sliding pairs, and the movement directions of the two sliding pairs are parallel to the movement direction of the lifting block.

4. The print carriage of claim 1, wherein: the two inserting strips are symmetrically distributed on two sides of the lifting block, the front ends of the two inserting strips are connected into a whole through the connecting plate, and the connecting plate is connected with the mounting plate through screws.

5. The print carriage of claim 1, wherein: the upper end and the lower end of the transmission screw rod are sleeved with bearing boxes, and the bearing boxes are fixed on the transverse moving plate through screws.

6. The print carriage of claim 1, wherein: the utility model discloses a shower nozzle, including mounting panel, shower nozzle bedplate, mounting panel and shower nozzle bedplate both ends symmetry fixedly connected with end plate, the lateral surface of every end plate is hung and is equipped with lower open-ended outer storehouse cover, is equipped with the UV lamp and the static-removing stick that shines downwards in outer storehouse cover, UV lamp and static-removing stick all install on the lateral surface of end plate through the bracket.

7. The print carriage of claim 6, wherein: the lateral surface of every outer storehouse cover be equipped with buffer stop, this buffer stop is including the fixed grillage of laminating outer storehouse cover installation and the swing board of articulated on the fixed grillage, the both ends of fixed grillage transversely stretch out and have two symmetrical support otic placodes, the both ends of swing board are equipped with the articulated otic placode that transversely stretches out the symmetry, articulated otic placode passes through the articulated shaft and is connected with support otic placode, be equipped with the limit baffle that transversely stretches out in the upper middle part of fixed grillage, the upper end of swing board transversely stretches out and has the apron on the whole length of coverage, the apron is located limit baffle upper portion, hang between apron and the fixed splint lower part and have reset spring, the touch switch that transversely stretches out is installed at the fixed splint lower part, touch switch is located the lower part inboard of swing board.

8. The print carriage of claim 1, wherein: the clamping mechanism comprises clamping bottom plates symmetrically arranged at two side edges of the back surface of the transverse plate and toothed pressing plates fixed on the clamping bottom plates through screws, and positioning grooves are formed in the middle of the clamping bottom plates.