CN220548971U - Electric turnover handrail - Google Patents

Abstract

The utility model discloses an electric turnover armrest, which comprises an armrest framework, a support frame and a support frame, wherein the armrest framework is used for being mounted to the side part of a seat back; the support assembly is rotatably arranged on the armrest framework and is provided with an expansion support plate, and the support assembly rotates relative to the armrest framework, so that the expansion support plate can be retracted at the side part of the armrest framework or horizontally expanded at the top of the armrest framework; the handrail framework is internally provided with a driving mechanism for driving the supporting component to rotate relative to the handrail framework. The beneficial effects of the utility model are as follows: the supporting component is driven to rotate through the driving mechanism, so that the expansion supporting plate can turn back and forth between the side part and the top of the armrest framework, electric intelligent adjustment of the armrest supporting width is realized, the comfort of the armrest of the chair is improved, and the armrest of the chair is high-grade.

Description

Electric turnover handrail

Technical Field

The utility model relates to the technical field of automobile seats, in particular to an electric turnover armrest.

Background

Automobile seats are important components of automobiles, and along with the improvement of life quality of people, people pay more and more attention to the quality, the quality and the use feeling of the automobile seats, and automobile seat armrests are important components for improving the comfort of the automobile seats.

Automotive armrests are a functional accessory, typically provided on the side of the seat, for supporting the hands of the occupant. Currently, in order to meet the needs of passengers when using armrests, the armrests of the seat are usually provided with rotatable expansion support plates, the support area of the armrests can be increased by manually turning over the expansion support plates, and the comfort of hand support of a user is improved.

However, with the increasing demands of users for automobile comfort, most of the functional mechanisms in the automotive interior systems are moving toward motorized intelligent adjustment, especially for high-end business cars, sedans, and the like.

Therefore, development of a seat armrest with an electric automatic overturning and expanding supporting plate is needed to meet the purchasing demands of middle-high-end automobile users.

Disclosure of Invention

In view of the above, the utility model provides an electric turnover armrest, which can electrically adjust the supporting width of the armrest and improve the user experience.

In order to achieve the above purpose, the technical scheme of the utility model is as follows:

an electric folding handrail is characterized by comprising:

an armrest frame for mounting to a seat back side;

the support component is rotatably arranged on the armrest framework and is provided with an expansion support plate; the support component rotates relative to the armrest framework, so that the expansion support plate can be retracted at the side part of the armrest framework or horizontally expanded at the top of the armrest framework; and

and the driving mechanism is used for driving the supporting component to rotate relative to the armrest framework.

By adopting the structure, when the expanding support plate is vertically folded at the side part of the armrest framework, the width of the armrest is narrower, and when the expanding support plate is horizontally unfolded to the top of the armrest framework, the support area of the armrest can be increased, and the comfort of hand support of a user is improved. The driving mechanism drives the supporting component to rotate relative to the armrest framework, so that the expansion supporting board can turn back and forth between the side part and the top of the armrest framework, electric intelligent adjustment of the width of the armrest is realized, and the experience of a user is improved.

As preferable: the support assembly comprises a first rotating shaft rotatably arranged in the armrest framework, and the expansion support plate is fixedly connected with the first rotating shaft through a first supporting lug;

the driving mechanism comprises a guide sleeve which is slidably arranged in the handrail framework and a first driving mechanism which drives the guide sleeve to slide, the guide sleeve is provided with a first central through hole, a guide groove is formed in the wall of the first central through hole, one end of the first rotating shaft is rotatably sleeved in the first central through hole, the surface of the first rotating shaft is provided with a guide part which is positioned in the guide groove, and the guide groove is a spiral groove;

the first driving mechanism drives the guide sleeve to slide, and the first rotating shaft can rotate in the first center through hole under the guiding action of the guiding part and the guiding groove. By adopting the structure, the first driving mechanism drives the guide sleeve to slide along the first rotating shaft, and the guide part can be forced to slide along the track of the spiral groove, so that the first rotating shaft is driven to rotate.

As preferable: the first driving mechanism comprises a first screw rod and a first motor for driving the first screw rod to rotate, one end of the guide sleeve is in threaded connection with the first screw rod, and the other end of the guide sleeve is sleeved on the first rotating shaft; the first motor drives the first screw rod to rotate and can drive the guide sleeve to axially move.

As preferable: one end of the guide groove is provided with a first straight line section. By adopting the structure, the guide part can be locked, and the expansion supporting plate is prevented from shaking.

As preferable: the support assembly comprises a second rotating shaft rotatably arranged in the armrest framework, the second rotating shaft can slide along the length direction of the armrest framework, and the expansion support plate is fixedly connected with the second rotating shaft through a second support lug;

the driving mechanism comprises a second driving mechanism for driving a second rotating shaft to slide and a supporting block fixedly arranged in the handrail framework, the supporting block is provided with a second central through hole, a guide groove is formed in the wall of the second central through hole, the second rotating shaft is rotatably arranged in the second central through hole in a penetrating manner and can slide relative to the second central through hole, a guide protrusion positioned in the guide groove is arranged on the surface of the second rotating shaft, and the guide groove is provided with a spiral section;

and the second driving mechanism drives the second rotating shaft to slide forwards and turn upwards relative to the supporting block under the guiding action of the guide protrusion and the guide groove in the sliding process of the second rotating shaft in the second central through hole. By adopting the structure, the second driving mechanism drives the second rotating shaft to slide in the second central through hole, and the guide protrusion can be forced to slide along the track of the spiral section, so that the second rotating shaft is driven to rotate while sliding, the width adjustment of the handrail is realized, and the forward movement of the handrail can be realized.

As preferable: the second driving mechanism comprises a second screw rod, a driving block slidingly assembled in the handrail framework and a second motor for driving the second screw rod to rotate, the driving block is sleeved on the second screw rod in a threaded mode, the second rotating shaft is sleeved on the driving block in a rotating mode, and the second rotating shaft and the driving block are kept relatively fixed in the axial direction of the second rotating shaft.

As preferable: the guide slot has a third straight section connected to the end of the spiral section. By adopting the structure, after the expansion supporting plate is overturned to the top of the armrest framework, the armrest framework can continuously move forwards along the length direction of the armrest framework, so that the requirements of each user on hand support are better met.

As preferable: the handrail framework is internally and fixedly provided with a guide rod which is arranged below the second rotating shaft in parallel, and the lower part of the driving block is in sliding sleeve joint with the guide rod. By adopting the structure, the driving block can slide more stably.

As preferable: the front part of the expansion supporting plate is slidably provided with a touch screen through a linkage mechanism, and the handrail framework is provided with a stop block;

in the forward linear sliding process of the guide bulge in the third straight line section, under the stop limit effect of the stop block, the linkage mechanism can force the touch screen to slide forward relative to the expansion support plate. By adopting the structure, through the configuration of the touch screen, each item of the seat can be intelligently operated, meanwhile, the forward movement function of the touch screen is increased, and the user is ensured to control the touch screen in a more stretching gesture.

Compared with the prior art, the utility model has the beneficial effects that:

1. by adopting the electric turnover armrest provided by the utility model, the supporting component is driven to rotate by the driving mechanism, so that the expansion supporting plate can turn back and forth between the side part and the top of the armrest framework, thereby realizing electric intelligent adjustment of the armrest supporting width, being beneficial to improving the comfort of the armrest and having high-grade feeling.

2. The electric turnover handrail provided by the utility model can realize the forward movement of the handrail while realizing the width adjustment of the handrail, and better meets the requirements of users with different body types on hand support.

3. Through configuration touch screen, can intelligent each item of operation seat adjust, simultaneously, increase touch screen antedisplacement function, guarantee that the user can control the touch screen with the gesture of stretching more.

Drawings

Fig. 1 is a schematic structural view of an electric folding armrest expanding support plate 2a in a folded state in a first embodiment;

fig. 2 is another schematic structural view of the electric folding handrail expanding support plate 2a according to the first embodiment;

fig. 3 is an exploded view of the electric folding handrail in the first embodiment (only the guide sleeve 3a and the support 1a are exploded);

fig. 4 is a schematic structural view showing an expanded state of the electric folding handrail expanding support plate 2a in the first embodiment;

fig. 5 is a schematic structural view of the guide sleeve 3 a;

fig. 6 is a schematic structural view of a folded state of an electric folding armrest expansion support plate 2a in the second embodiment;

fig. 7 is an exploded view of the electric folding handrail of the second embodiment (only the supporting block 31 and the driving block 322 are exploded);

fig. 8 is a schematic structural view of the supporting block 31;

fig. 9 is a schematic structural view of an expanded state of an electric folding handrail expanding support plate 2a in the second embodiment;

fig. 10 is a front view showing an expanded state of the electric folding handrail expanding support plate 2a in the second embodiment;

fig. 11 is another schematic structural view (with the touch screen 6 hidden) of the extended state of the electric folding armrest expansion support plate 2a in the second embodiment;

fig. 12 is a view of a use state reference of a car seat with an electric fold-back armrest.

Detailed Description

The utility model is further described below with reference to examples and figures.

As shown in fig. 12, an automobile seat comprises a seat backrest framework a, wherein an electric folding handrail B is arranged on the side part of the seat backrest framework a, and as can be seen from fig. 1, a connecting shaft B1 is arranged at the end part of the electric folding handrail B, and the electric folding handrail B is arranged on the side part of the seat backrest framework a through the connecting shaft B1. In practical application, the electric turnover armrest B can be fixedly and horizontally arranged at the side part of the seat back framework A, and can also be rotatably arranged at the side part of the seat back framework A. When the electric folding armrest B is rotatably mounted to the side of the seat back skeleton A, the armrest can be folded on the side of the backrest by a manual or electric regulator. The armrest body is rotated and folded at the side part of the backrest by conventional technical means, and will not be described herein.

As shown in fig. 1 and 4, the electric folding handrail B comprises a handrail framework 1, and a supporting component 2 is rotatably installed on the handrail framework 1, and the supporting component 2 is provided with an expanding supporting plate 2a. The support component 2 rotates relative to the armrest framework 1, so that the expanding support plate 2a can be folded at the side part of the armrest framework 1, or the expanding support plate 2a can be horizontally unfolded at the top of the armrest framework 1. A driving mechanism 3 is also arranged in the armrest framework 1 and is used for driving the supporting component 2 to rotate relative to the armrest framework 1.

Based on the structural design, when the expansion support plate 2a is vertically folded at the side part of the armrest framework 1, the support surface at the upper end of the armrest is narrower, and the movable space in the vehicle is not influenced. When the supporting surface of the upper end of the handrail needs to be enlarged, the supporting component 2 can be driven by the driving mechanism 3 to rotate 90 degrees relative to the handrail framework 1, namely, the expansion supporting plate 2a is turned upwards by 90 degrees from the side part of the handrail framework 1 and is supported at the top of the handrail framework 1 in a horizontal state, at the moment, the width of the upper end of the handrail is enlarged, namely, the supporting surface is enlarged, and the comfort of supporting the hands of a passenger can be improved. Through setting up actuating mechanism 3, can realize the electronic intelligent regulation of handrail width, satisfy the intelligent demand of car, promote the holistic quality of car.

Referring to fig. 12 again, the outside of the armrest skeleton 1 is covered with a flexible cover 7, and the surface of the expansion support plate 2a is wrapped with a flexible support layer 8, so that the comfort of hand support can be further improved.

The following provides two embodiments for describing the turning drive mechanism 3 of the electric turning handrail B in detail.

Example 1

Referring to fig. 1 and 2, the support assembly 2 includes a first rotation shaft 2b rotatably installed in the armrest frame 1, the first rotation shaft 2b being disposed along a length direction of the armrest frame 1. Two groups of first brackets 1b are fixedly arranged in the armrest framework 1, and a first rotating shaft 2b is rotatably arranged on the first brackets 1 b. The expansion support plate 2a has first lugs 2c which are bent, in this embodiment, the number of the first lugs 2c is two, and the expansion support plate 2a is fixedly connected with the first rotation shaft 2b through the two first lugs 2 c. The driving mechanism 3 includes a guide sleeve 3a slidably mounted in the armrest frame 1, and a first driving mechanism 3b driving the guide sleeve 3a to slide. Referring again to fig. 3, 4 and 5, the guide sleeve 3a has a first central through hole 3a1, and the rear end of the first rotation shaft 2b is rotatably fitted in the first central through hole 3a 1. The hole wall of the first central through hole 3a1 is provided with a guide groove 3a2, the guide groove 3a2 is a spiral groove, the surface of the first rotating shaft 2b is fixedly provided with a guide part 2b1, and the guide part 2b1 is positioned in the guide groove 3a 2.

In the folded state of the expansion support plate 2a, the guide part 2b1 is located at the front end of the guide groove 3a2, the guide sleeve 3a is driven by the first driving mechanism 3b to move forwards axially, the guide part 2b1 can be forced to slide to the rear end along the front end of the spiral groove, the guide part 2b1 rotates to drive the first rotating shaft 2b to rotate, and therefore the expansion support plate 2a is driven to overturn to the top of the handrail framework 1. On the contrary, the first driving mechanism 3b drives the guide sleeve 3a to move axially backwards, so that the expanding support plate 2a can be folded at the side part from the top of the armrest framework 1.

In order to make the expansion support plate 2a more stably supported on the top of the armrest frame 1, please refer to fig. 5 and 6, in the present embodiment, the rear end of the guide slot 3a2 has a first straight line segment a. By the design, the guide part 2b1 positioned at the rear end can be locked, the guide part 2b1 is prevented from being inclined, and the stability of the handrail in use is ensured.

As shown in fig. 2 to 4, the first driving mechanism 3b includes a first screw 3b1 and a first motor 3b2 for driving the first screw 3b1 to rotate, wherein the axis of the first screw 3b1 coincides with the axis of the first rotary shaft 2 b. The rear part of the guide sleeve 3a is in threaded connection with the first screw rod 3b1, and the front part of the guide sleeve is sleeved on the first rotating shaft 2 b. The first motor 3b2 drives the first screw rod 3b1 to rotate, and can drive the guide sleeve 3a to axially move along the first rotating shaft 2 b.

Further, as shown in fig. 3 and 4, a support 1a is fixedly installed in the armrest frame 1, and is used for supporting the guide sleeve 3a to axially move. The support 1a is provided with a third central through hole 1a1 matched with the guide sleeve 3a, and the guide sleeve 3a is arranged in the third central through hole 1a1 in a sliding manner.

Referring to fig. 3 and 5 again, the guide sleeve 3a has a guide bar 3a3 disposed along the length direction thereof, and a limit groove 1a2 corresponding to the guide bar 3a3 is disposed on the sidewall of the third central through hole 1a 1. By the design, the guide sleeve 3a can be prevented from deflecting during axial movement, and the accuracy of the rotation angle of the first rotating shaft 2b can be ensured. In this embodiment, the guide strips 3a3 are provided with two strips, which are respectively located at the bottom and the side of the guide sleeve 3 a.

In practical applications, the first motor 3b2 is not limited to be disposed at the rear end of the handrail, but may be disposed at the front end of the handrail.

Example two

As shown in fig. 6, the support assembly 2 includes a second rotation shaft 21 rotatably installed in the armrest frame 1, the second rotation shaft 21 being disposed along a length direction of the armrest frame 1 and being capable of sliding back and forth with respect to the armrest frame 1. The expansion support plate 2a is provided with two groups of second lugs 22 which are bent, and the expansion support plate 2a is fixedly connected with the second rotating shaft 21 through the second lugs 22. As can be seen in connection with fig. 7-9, the drive mechanism 3 comprises a second drive mechanism 32 for driving the second rotation shaft 21 to slide, and a support block 31 fixedly mounted in the handrail frame 1. The support block 31 has a second center through hole 311 at an upper portion thereof, and the second rotation shaft 21 is rotatably fitted in the second center through hole 311 and is slidable with respect to the second center through hole 311. The wall of the second central through hole 311 is provided with a guide groove b having a spiral section b1, and the surface of the second rotation shaft 21 is provided with a guide protrusion 211 protruding outward, the guide protrusion 211 being located in the guide groove b.

In the folded state of the expansion support plate 2a, the guide protrusion 211 is located at the start end of the spiral section b1, and the second driving mechanism 32 drives the second rotation shaft 21 to axially slide forward in the second central through hole 311, so that the guide protrusion 211 can be forced to slide to the tail end (i.e., the top of the support block 31) along the start end of the spiral section b1, and the second rotation shaft 21 is driven to move forward and simultaneously can rotate upwards by 90 degrees, so that the expansion support plate 2a is driven to be folded to the top of the armrest framework 1 from the side of the armrest framework 1.

Referring to fig. 8, in the present embodiment, the start end of the spiral section b1 has a second straight-line section b11, which can play a role in locking the guiding protrusion 211, so as to ensure that the expanding support plate 2a can be folded on the side of the armrest frame 1 more stably.

As further shown in fig. 7 to 9, the guide groove b has a third straight line section b2 arranged along the length of the support block 31, and the third straight line section b2 is connected to the end of the spiral section b 1. When the second rotation shaft 21 slides forward, under the guiding constraint of the spiral section b1 and the third straight line section b2, the expansion support plate 2a can be folded up by 90 ° from the side of the armrest skeleton 1 and then moves forward. By the design, the requirements of each rider on hand support can be met in an omnibearing manner, so that riders with different bodies and different sitting postures can support the hands on the armrests comfortably.

Referring to fig. 7 and 9, the second driving mechanism 32 includes a second screw rod 321, a driving block 322, and a second motor 323 for driving the second screw rod 321 to rotate, wherein an axis of the second screw rod 321 coincides with an axis of the second rotary shaft 21. The upper portion of the driving block 322 has a first connection through hole d, the rear end of which is screw-fitted over the second screw rod 321, and the front end is rotatably coupled with the second rotation shaft 21 through the stepped pin 4. The second rotation shaft 21 is provided with an arc notch c arranged along the circumferential direction, the central angle corresponding to the arc notch c is 90 degrees, and the lower end of the step pin 4 is embedded into the arc notch c. So designed, when the second driving mechanism 32 drives the second screw rod 321 to rotate, the second rotating shaft 21 can be ensured to synchronously and axially move along with the driving block 322, and meanwhile, the second rotating shaft 21 can rotate by 90 degrees relative to the driving block 322.

Further, referring again to fig. 6 and 7, a guide rod 11 is fixedly installed in the armrest frame 1, and is disposed in parallel below the second rotation shaft 21. The lower portion of the driving block 322 has a second coupling through hole e slidably fitted over the guide rod 11. In this regard, the drive block 322 can be made to slide axially more smoothly.

Still further, as shown in fig. 6 and 10, a second bracket 13 is fixedly installed in the armrest frame 1 near the front end, a motor bracket 14 is fixedly installed in the armrest frame 1 near the rear end, and a second motor 323 is fixedly connected with the motor bracket 14. The front end of the second rotation shaft 21 is slidably connected to the second bracket 13, and the second rotation shaft 21 is rotatable relative to the second bracket 13. So designed, the supporting strength of the second rotation shaft 21 can be improved.

Referring again to fig. 10, in order to facilitate the fixed installation of the guide bar 11, one end of the guide bar 11 is fixedly connected with the lower portion of the supporting block 31, and the other end is fixedly connected with the motor bracket 14.

As shown in fig. 9, the touch screen 6 is installed on the upper side of the expansion support plate 2a, the touch screen 6 is integrated with the adjusting function of each intelligent accessory in the automobile, and an occupant can adjust each function of the accessories and the seat in the automobile by operating the touch screen 6, so that the user experience is further improved.

Referring to fig. 9, 10 and 11 again, the touch screen 6 is slidably mounted in front of the expansion support plate 2a through the linkage mechanism 5, and the handrail framework 1 is provided with a stop block 12. In the forward linear sliding process of the guide protrusion 211 in the third straight line section b2, under the stop limit effect of the stop block 12, the linkage mechanism 5 can force the touch screen 6 to slide forward relative to the expansion support plate 2a, so that a user can control the touch screen 6 in a more stretched posture.

In practical applications, the second motor 323 is not limited to be disposed at the rear end of the handrail, but may be disposed at the front end of the handrail.

Finally, it should be noted that the above description is only a preferred embodiment of the present utility model, and that many similar changes can be made by those skilled in the art without departing from the spirit and scope of the utility model as defined in the appended claims.

Claims (9)

1. An electric fold-over armrest, comprising:

an armrest frame (1) for mounting to a seat back side;

the support component (2) is rotatably arranged on the handrail framework (1), and the support component (2) is provided with an expansion support plate (2 a); the support component (2) rotates relative to the armrest framework (1) and can enable the expansion support plate (2 a) to be received at the side part of the armrest framework (1) or enable the expansion support plate (2 a) to be horizontally unfolded at the top of the armrest framework (1); and

and the driving mechanism (3) is used for driving the supporting component (2) to rotate relative to the armrest framework (1).

2. An electrically powered flip handrail as claimed in claim 1, wherein: the support assembly (2) comprises a first rotating shaft (2 b) rotatably installed in the armrest framework (1), and the expansion support plate (2 a) is fixedly connected with the first rotating shaft (2 b) through a first supporting lug (2 c);

the driving mechanism (3) comprises a guide sleeve (3 a) which is slidably arranged in the handrail framework (1) and a first driving mechanism (3 b) which drives the guide sleeve (3 a) to slide, the guide sleeve (3 a) is provided with a first central through hole (3 a 1), a guide groove (3 a 2) is formed in the hole wall of the first central through hole (3 a 1), one end of a first rotating shaft (2 b) is rotatably sleeved in the first central through hole (3 a 1), a guide part (2 b 1) which is positioned in the guide groove (3 a 2) is arranged on the surface of the first rotating shaft (2 b), and the guide groove (3 a 2) is a spiral groove;

the first driving mechanism (3 b) drives the guide sleeve (3 a) to slide, and the first rotating shaft (2 b) can rotate in the first center through hole (3 a 1) under the guiding action of the guiding part (2 b 1) and the guiding groove (3 a 2).

3. An electrically powered flip handrail as claimed in claim 2, wherein: the first driving mechanism (3 b) comprises a first screw rod (3 b 1) and a first motor (3 b 2) for driving the first screw rod (3 b 1) to rotate, one end of the guide sleeve (3 a) is in threaded connection with the first screw rod (3 b 1), and the other end of the guide sleeve is sleeved on the first rotating shaft (2 b); the first motor (3 b 2) drives the first screw rod (3 b 1) to rotate, and the guide sleeve (3 a) can be driven to axially move.

4. An electrically powered flip handrail as claimed in claim 2, wherein: one end of the guide groove (3 a 2) is provided with a first straight line section (a).

5. An electrically powered flip handrail as claimed in claim 1, wherein: the support assembly (2) comprises a second rotating shaft (21) rotatably arranged in the armrest framework (1), the second rotating shaft (21) can slide along the length direction of the armrest framework (1), and the expansion support plate (2 a) is fixedly connected with the second rotating shaft (21) through a second support lug (22);

the driving mechanism (3) comprises a second driving mechanism (32) for driving the second rotating shaft (21) to slide and a supporting block (31) fixedly installed in the handrail framework (1), the supporting block (31) is provided with a second central through hole (311), a guide groove (b) is formed in the hole wall of the second central through hole (311), the second rotating shaft (21) is rotatably arranged in the second central through hole (311) in a penetrating manner and can slide relative to the second central through hole (311), a guide protrusion (211) positioned in the guide groove (b) is arranged on the surface of the second rotating shaft (21), and the guide groove (b) is provided with a spiral section (b 1);

the second driving mechanism (32) drives the second rotating shaft (21) to slide in the second central through hole (311), and the second rotating shaft (21) can slide forwards and turn upwards relative to the supporting block (31) under the guiding action of the guide protrusion (211) and the guide groove (b).

6. An electrically powered flip handrail as claimed in claim 5, wherein: the second driving mechanism (32) comprises a second screw rod (321), a driving block (322) slidably assembled in the handrail framework (1) and a second motor (323) for driving the second screw rod (321) to rotate, the driving block (322) is sleeved on the second screw rod (321) in a threaded mode, the second rotating shaft (21) is sleeved on the driving block (322) in a rotating mode, and the second rotating shaft (21) and the driving block (322) are kept relatively fixed in the axial direction of the second rotating shaft (21).

7. An electrically powered flip handrail as claimed in claim 5, wherein: the guide groove (b) has a third straight section (b 2) which is connected to the end of the spiral section (b 1).

8. An electrically powered flip handrail as claimed in claim 6, wherein: the handrail framework (1) is internally and fixedly provided with a guide rod (11), the guide rod is arranged below the second rotating shaft (21) in parallel, and the lower part of the driving block (322) is in sliding sleeve joint with the guide rod (11).

9. An electrically powered flip handrail as claimed in claim 7, wherein: the front part of the expansion supporting plate (2 a) is slidably provided with a touch screen (6) through a linkage mechanism (5), and a stop block (12) is arranged on the handrail framework (1);

in the forward linear sliding process of the guide protrusion (211) in the third straight line section (b 2), under the stop limit effect of the stop block (12), the linkage mechanism (5) can force the touch screen (6) to slide forward relative to the expansion support plate (2 a).