WO2024139534A1 - Positive and negative electrode pantograph and electrified vehicle - Google Patents

Abstract

A positive and negative electrode pantograph and an electrified vehicle. The positive and negative electrode pantograph comprises an underframe (5), a positive electrode power receiving assembly (2), and a negative electrode power receiving assembly (3); the positive electrode power receiving assembly (2) and the negative electrode power receiving assembly (3) are both mounted on the underframe (5); the positive electrode power receiving assembly (2) comprises a positive electrode bow (21), a positive electrode upper arm (22), a positive electrode lower arm (23), and a positive electrode rod mechanism (24) used for adjusting the height of the positive electrode bow (21); the lower end of the positive electrode upper arm (22) is hingedly connected to the upper end of the positive electrode lower arm (23), the upper end of the positive electrode upper arm (22) is connected to the positive electrode bow (21), and the lower end of the positive electrode lower arm (23) is mounted on the underframe (5); the negative electrode power receiving assembly (3) comprises a negative electrode bow (31), a negative electrode upper arm (32), a negative electrode lower arm (33), and a negative electrode rod mechanism (34) used for adjusting the height of the negative electrode bow (31); the lower end of the negative electrode upper arm (32) is hingedly connected to the upper end of the negative electrode lower arm (33), the upper end of the negative electrode upper arm (32) is connected to the negative electrode bow (31), and the lower end of the negative electrode lower arm (33) is mounted on the underframe (5); a torsion limiting device (6) is provided between the negative electrode lower arm (33) and the positive electrode lower arm (23); and the width of the positive electrode bow (21) and the negative electrode bow (31) is smaller than the distance between the centers of the positive electrode bow (21) and the negative electrode bow (31).

Description

Positive and negative pole pantograph and electrified vehicle

This application claims the priority of the Chinese patent application filed with the China Patent Office on December 26, 2022, with application number 202211673677.2 and invention name “A positive and negative pole pantograph and electrified vehicle”, all contents of which are incorporated by reference in this application.

Technical Field

The present invention relates to the field of vehicle power receiving equipment, and more specifically, to a positive and negative pantograph and an electrified vehicle.

Background technique

With the continuous advancement of my country's industrialization and urbanization, the total energy consumption has jumped to the first place in the world. The bottleneck of energy on China's economic and social development is becoming increasingly apparent, and the problems of relatively insufficient energy supply, unreasonable energy structure and the resulting environmental pollution are becoming increasingly prominent. According to statistics, although commercial vehicles, mainly trucks, account for only 10.9% of the total number of vehicles in my country, they consume 51% of the total fuel consumption, emit 80% of the air pollutants emitted by vehicles, and emit 56% of the national carbon dioxide emissions from vehicles.

Therefore, promoting the development of new energy and clean energy for trucks is the key to achieving carbon reduction in the transportation sector. One effective measure is to build electrified roads, set up overhead wires on the roads, and use the positive and negative pantographs of the present invention to obtain current from the overhead wires above the roads to drive the motors on the trucks and achieve traction of the entire vehicle.

The positive and negative pantographs for trucks are different from the existing pantographs for rail vehicles. Their main feature is that they need to be suitable for the characteristics of electrified highway contact networks to collect current.

In the prior art, the pantograph is installed on the roof through a four-bar mechanism, and obtains current from the positive grid and the negative grid respectively. However, since the vehicle is prone to bumps during driving, the stability of the current obtained by the pantograph will be affected.

Summary of the invention

In order to solve the above technical problems, the present invention provides a positive and negative pantograph, and the positive pantograph and the negative pantograph receive power independently, which can improve the stability of power reception during vehicle driving.

If necessary, an electrified vehicle equipped with the above-mentioned positive and negative pantographs is also provided.

The technical solution provided by the present invention is as follows:

A positive and negative pantograph,

It includes a chassis, a positive power receiving assembly and a negative power receiving assembly;

The positive electrode power receiving assembly and the negative electrode power receiving assembly are both mounted on the base frame;

The positive electrode power receiving assembly includes a positive electrode bow, a positive electrode upper arm, a positive electrode lower arm and a positive electrode rod mechanism for adjusting the height of the positive electrode bow;

The lower end of the positive upper arm is hinged to the upper end of the positive lower arm, the upper end of the positive upper arm is connected to the positive bow, and the lower end of the positive lower arm is mounted on the base frame;

The negative electrode power receiving assembly includes a negative electrode bow, a negative electrode upper arm, a negative electrode lower arm and a negative electrode rod mechanism for adjusting the height of the negative electrode bow;

The lower end of the negative upper arm is hinged to the upper end of the negative lower arm, the upper end of the negative upper arm is connected to the negative bow, and the lower end of the negative lower arm is mounted on the base frame;

A torsion limiting device is provided between the negative electrode lower arm and the positive electrode lower arm;

The widths of the positive bow and the negative bow are smaller than the distance between the centers of the positive bow and the negative bow.

Among them, the positive lower arm is rotatably mounted on the base frame through the positive cross bar, and the negative lower arm is rotatably mounted on the base frame through the negative cross bar. The axes of the positive cross bar and the negative cross bar are located on a straight line, and one end of the positive cross bar and one end of the negative cross bar are provided with a torsion limiting device.

Among them, the torsion limit device includes a positive limit block and a negative limit block, the positive limit block is connected to one end of the positive pole cross bar, and the negative limit block is connected to one end of the negative pole cross bar. The positive limit block and the negative limit block are respectively provided with mutually meshing teeth along the circumference of the positive pole cross bar and the circumference of the negative pole cross bar, and a distance is left between the teeth.

Among them, positive bow angles are provided on both sides of the positive bow, and negative bow angles are provided on both sides of the negative bow. The lowest end of the positive bow angle is at a height h from the highest point of the positive bow in the vertical direction, and the lowest end of the negative bow angle is at a height h from the highest point of the negative bow in the vertical direction.

Among them, the distance between the pairs of teeth can limit the maximum angle of mutual twisting of the positive cross bar and the positive cross bar to D°, and the maximum height difference between the top of the positive upper arm and the top of the negative upper arm is C; C is less than or equal to h.

Wherein, a bow raising device is provided on the base;

The positive pole rod mechanism comprises a positive pole lower pull rod and a positive pole upper pull rod, the positive pole lower pull rod is hinged on the bow lifting device, and the upper end of the positive pole lower pull rod is hinged to the lower end of the positive pole upper arm;

The lower end of the positive electrode upper pull rod is hinged to the positive electrode lower arm, and the upper end of the positive electrode upper pull rod is hinged to the middle part of the positive electrode bow.

Wherein, the negative pole rod mechanism comprises a negative pole lower pull rod and a negative pole upper pull rod, the negative pole lower pull rod is hinged on the bow lifting device, and the upper end of the negative pole lower pull rod is hinged to the lower end of the negative pole upper arm;

The lower end of the negative pole upper pull rod is hinged to the negative pole lower arm, and the upper end of the negative pole upper pull rod is hinged to the middle part of the negative pole bow.

Wherein, the positive pole bow angle and the negative pole bow angle are both made of insulating material.

Wherein, the bow lifting device is made of insulating material.

Among them, the positive and negative pantographs as described above are installed on the roof.

The base frame is installed on the roof, and an insulator is arranged between the bottom of the base frame and the roof.

Compared with the prior art, the positive and negative pantographs of the present invention are installed on the roof through the chassis, and have independent positive power receiving components and negative power receiving components. The positive and negative pantographs can independently adapt to the different height differences between the positive and negative network cables. There is a torsion limiter between the positive and negative pantographs to ensure that the height difference between the positive and negative pantograph slides is ≤C relative to the negative pantograph at any height and under current receiving conditions. When the pantograph of one pole does not contact the network cable, the pantograph will only be lifted to a limited height due to the action of the specially designed limiter. The network cable on the pantograph slide of the other pole slides horizontally, and can be transitioned through the bow angle on the bow head of the pantograph to slide to the other pantograph, allowing the network cable to have a larger offset on the upper surface of the pantograph slide, which better adapts to the current receiving limitation of the highway contact network.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a front view of an electrified vehicle of the present invention;

FIG2 is an overall schematic diagram of an electrified vehicle of the present invention;

FIG3 is an overall schematic diagram of the positive and negative pantographs of the present invention;

FIG4 is a diagram showing the working state of the positive and negative pantographs of the present invention without twisting;

FIG5 is a diagram showing the working state of the positive and negative pantographs of the present invention when maximum torsion occurs;

FIG6 is a schematic diagram of the installation of the torsion limiting device of the present invention;

FIG7 is a schematic diagram of a torsion limiting device of the present invention;

FIG8 is a schematic structural diagram of a bow raising device according to the present invention;

Figure 9 is a schematic diagram of the working principle of the bow lifting device;

In the figure, the roof 1, the positive power receiving component 2, the negative power receiving component 3, the power grid 4, the chassis 5, the torsion limiting device 6, the bow lifting device 7, the insulator 8, the positive bow 21, the positive upper arm 22, the positive lower arm 23, the positive rod mechanism 24, the positive upper pull rod 241, the positive lower pull rod 242, the positive cross bar 25, the positive bow angle 26, the negative bow 31, the negative upper arm 32, the negative lower arm 33, the negative rod mechanism 34, the negative upper pull rod 341, the negative lower pull rod 342, the negative cross bar 35, the negative bow angle 36, the positive limit block 61, the negative limit block 62, and the counter tooth 63.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The feature of "two" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meanings of "multiple" and "several" are two or more, unless otherwise clearly and specifically defined.

It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportional relationship, or adjustment of size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

The embodiments of the present invention are written in a progressive manner.

In conjunction with Figures 1 to 7, a positive and negative pantograph,

The positive electrode power receiving assembly 2 and are both mounted on the base frame 5;

The positive electrode power receiving assembly 2 includes a positive electrode bow 21, a positive electrode upper arm 22, a positive electrode lower arm 23 and a positive electrode rod mechanism 24 for adjusting the height of the positive electrode bow 21;

The lower end of the positive electrode upper arm 22 is hinged to the upper end of the positive electrode lower arm 23, the upper end of the positive electrode upper arm 22 is connected to the positive electrode bow 21, and the lower end of the positive electrode lower arm 23 is installed on the bottom frame 5;

The negative electrode power receiving assembly 3 includes a negative electrode bow 31, a negative electrode upper arm 32, a negative electrode lower arm 33 and a negative electrode rod mechanism 34 for adjusting the height of the negative electrode bow 31;

The lower end of the negative upper arm 32 is hinged to the upper end of the negative lower arm 33, the upper end of the negative upper arm 32 is connected to the negative bow 31, and the lower end of the negative lower arm 33 is installed on the bottom frame 5;

A torsion limiting device 6 is provided between the negative electrode lower arm 33 and the positive electrode lower arm 23;

The width of the positive electrode bow 21 and the negative electrode bow 31 is smaller than the distance between the centers of the positive electrode bow 21 and the negative electrode bow 31 .

As shown in Figure 1, the positive and negative pantographs are installed on the roof 1 and in contact with the power grid 4 to obtain positive and negative currents respectively. According to the road conditions and the bumps caused by the vehicle's driving process, or the scene where there is a height difference between the positive and negative contact networks of the power grid 4, the positive rod mechanism 24 adjusts the height of the positive bow 21, and the negative rod mechanism 34 adjusts the height of the negative bow 31. The heights of the positive bow 21 and the negative bow 31 are adjusted respectively, which can maximize the guarantee that the positive bow 21 and the negative bow 31 maintain good contact with the power grid 4, thereby improving the pantograph network followability and current collection performance.

Since the pantograph of the present invention uses the positive bow 21 and the negative bow 31 to receive current independently, the height difference between the negative bow 31 and the positive bow 21 may greatly exceed the height of the bow angle. When the slide plate of the bow 21 slides toward the negative pole bow 31 and slides to the bow angle of the positive pole bow 21, it is very easy to scrape the bow angle of the negative pole bow 31, resulting in scraping. To prevent this phenomenon from occurring, a torsion limiter 6 is provided between the negative pole lower arm 33 and the positive pole lower arm 23, so that the torsion angle between the negative pole lower arm 33 and the positive pole lower arm 23 is not too large to cause the pantograph to be unable to receive electricity. At the same time, the width of the positive pole bow 21 and the negative pole bow 31 is smaller than the distance between the centers of the positive pole bow 21 and the negative pole bow 31, so that the network line of the power grid 4 can slide left and right on the positive pole bow 21 and the negative pole bow 31, so that the network line has a larger lateral movement distance on the upper surface of the slide plates of the positive pole bow 21 and the negative pole bow 31, allowing the vehicle to have a larger offset when driving on the road, and a single contact network line can slide from the positive pole bow 21 slide plate through the bow angle to the negative pole bow 31 slide plate, and then slide to the positive pole bow 21 slide plate, which better adapts to the limitation of the current collection of the highway contact network.

At the same time, the width of the positive bow 21 and the negative bow 31 is smaller than the distance between the centers of the positive bow 21 and the negative bow 31, which can avoid the positive bow 21 or the negative bow 31 contacting the positive contact network and the negative contact network at the same time to cause a short circuit, thereby ensuring safety.

The positive lower arm 23 of the present invention is rotatably mounted on the base frame 5 through the positive cross bar 25, and the negative lower arm 33 is rotatably mounted on the base frame 5 through the negative cross bar 35. The axes of the positive cross bar 25 and the negative cross bar 35 are located on a straight line, and a torsion limiting device 6 is provided at one end of the positive cross bar 25 and one end of the negative cross bar 35. The axes of the positive cross bar 25 and the negative cross bar 35 are located on a straight line, the positive lower arm 23 and the positive cross bar 25 are perpendicular, and the negative lower arm 33 and the negative cross bar 35 are perpendicular. When the positive lower arm 23 and the negative lower arm 33 are twisted with each other, the positive cross bar 25 and the negative cross bar 35 rotate clockwise or counterclockwise along the axis, and the torsion limiting device 6 limits the relative torsion angle of the positive cross bar 25 and the negative cross bar 35, thereby limiting the mutual torsion angle of the positive lower arm 23 and the negative lower arm 33, thereby limiting the height difference between the top of the positive lower arm 23 and the top of the negative lower arm 33.

As shown in Figures 6 and 7, the torsion limit device 6 of the present invention includes a positive limit block 61 and a negative limit block 62. The positive limit block 61 is connected to one end of the positive pole cross bar 25, and the negative limit block 62 is connected to one end of the negative pole cross bar 35. The positive limit block 61 and the negative limit block 62 are respectively provided with mutually meshing teeth 63 along the circumference of the positive pole cross bar 25 and the circumference of the negative pole cross bar 35, and a distance is left between the teeth 63.

When the positive cross bar 25 and the negative cross bar 35 are twisted relative to each other, the positive limit block 61 and the negative limit block 62 are also twisted relative to each other. At this time, the teeth 63 approach each other until the contact is limited, limiting the further twisting of the positive limit block 61 and the negative limit block 62, thereby limiting the twisting of the positive cross bar 25 and the negative cross bar 35. At this time, the limit twisting angle of the positive cross bar 25 and the negative cross bar 35 is also reached.

The distance left between the teeth 63 allows the positive pole cross bar 25 and the negative pole cross bar 35 to twist freely when the torsion angle is within the maximum torsion angle range. This is beneficial for the pantograph to adjust its height to suit the road conditions at the time and to ensure the power receiving stability to the maximum extent.

As shown in Figures 4 and 5, positive bow angles 26 are provided on both sides of the positive bow 21 of the present invention, and negative bow angles 36 are provided on both sides of the negative bow 31. The lowest end of the positive bow angle 26 is at a height h from the highest point of the positive bow 21 in the vertical direction, and the lowest end of the negative bow angle 36 is at a height h from the highest point of the negative bow 31 in the vertical direction.

The distance between the teeth 63 can limit the maximum angle of rotation between the positive crossbar 25 and the positive crossbar 25 to D°, and the maximum height difference between the top of the positive upper arm 22 and the top of the negative upper arm 32 is C; C is less than or equal to h.

When a grid line 4 slides from the upper surface of the positive bow 21 slide plate to the negative bow 31 slide plate, the positive bow 21 is restricted by the network cable, and the height of the slide plate of the positive bow 21 from the roof 1 is F. The negative bow 31 is not restricted by the contact network cable. Due to the existence of the torsion limiting device 6 between the positive and negative bows 31, the negative bow 31 will only rise to a limited height C relative to the positive bow 21 under the drive of the negative rod mechanism 34. The total height of the negative bow 31 is F+C. Due to the existence of the torsion limiting mechanism, the negative bow 31 will not rise any further. The negative pole bow 31 bow head slide board will only be higher than the positive pole bow 21 bow head slide board by a distance C, and the distance C is less than the height h of the bow angle, so that the positive pole network line can slide from the positive bow slide board to the bow angle, and under the transition effect of the positive pole bow angle 26 and the negative pole bow angle 36, slide onto the negative pole bow 31 slide board, so that the displacement distance of the vehicle under the contact network line can be greatly increased, and a single contact network line can slide from the positive pole bow 21 slide board through the bow angle to the negative pole bow 31 slide board, and then slide to the positive pole bow 21 slide board.

A bow raising device 7 is provided on the base; the bow raising device 7 may be a spring box;

The positive pole rod mechanism 24 includes a positive pole lower pull rod 242 and a positive pole upper pull rod 241. The positive pole lower pull rod 242 is hinged on the bow lifting device 7. The upper end of the positive pole lower pull rod 242 is hinged to the lower end of the positive pole upper arm 22.

The lower end of the positive electrode upper pull rod 241 is hinged to the positive electrode lower arm 23 , and the upper end of the positive electrode upper pull rod 241 is hinged to the middle part of the positive electrode bow 21 .

The negative pole rod mechanism 34 includes a negative pole lower pull rod 342 and a negative pole upper pull rod 341. The negative pole lower pull rod 342 is hinged on the bow lifting device 7. The upper end of the negative pole lower pull rod 342 is hinged to the lower end of the negative pole upper arm 32.

The lower end of the negative pole upper pull rod 341 is hinged to the negative pole lower arm 33 , and the upper end of the negative pole upper pull rod 341 is hinged to the middle part of the negative pole bow 31 .

The positive pole bow angle 26 and the negative pole bow angle 36 of the present invention are both made of insulating materials. Such a design can ensure that when the vehicle deviates to any position, the slide plate of the positive pole bow 21 or the negative pole bow 31 will not contact the positive and negative pole contact network at the same time, avoiding short circuit accidents and ensuring the safety of contact network power supply. When the network line slides on the positive and negative pole pantograph slide plates, the positive and negative pole pantographs will not short-circuit the positive and negative pole contact network lines.

The pantograph lifting device 7 of the present invention is made of insulating material, which further ensures the insulation between the positive and negative pantographs and the vehicle, ensuring safety. The chassis of the bipolar pantograph is installed on the roof of the truck through an insulator. The chassis itself is not charged, and is connected to the roof of the truck through an insulator, adding an extra layer of insulation protection, which improves the safety of the entire pantograph relative to the truck.

As an optional implementation, take the positive electrode power receiving assembly 2 as an example: as shown in FIG8 , the bow lifting device 7 is composed of a driving plate 71, an air bag 72 and a steel wire 73. One end of the driving plate 71 is hinged to the base frame 5, and the other end of the driving plate 71 is hinged to the positive lower arm 23; one end of the air bag 72 is hinged to the base frame 5, and the other end of the air bag 72 is hinged to the driving plate 71; one end of the steel wire 73 is hinged to the driving plate 71, and the other end of the steel wire 73 is hinged to the positive lower arm 23. As shown in FIG9 , when the airbag 72 is filled with compressed air, it expands upward and applies an upward force to the driving plate 71. The driving plate 71 rotates counterclockwise around point A, and the driving plate 71 drives the steel wire 73 upward. The steel wire 73 drives the positive lower arm 23 to rotate clockwise around point C. The chassis 5 is fixed. When the positive lower arm 23 rotates clockwise around point C, it drives the positive upper arm 22, the positive rod mechanism 24 rotates, and the positive bow 21 rises. The negative power receiving assembly 3 has the same mechanism and is connected to the bow lifting device 7 in the same way. The positive and negative poles are independent of each other and can independently achieve bow lifting. The positive and negative poles are limited by the torsion limiter 6 to limit the relative position between the positive and negative poles.

The present invention also provides an electrified vehicle, wherein the positive and negative pantographs as above are mounted on the roof 1, the chassis 5 is mounted on the roof 1, and an insulator 8 is provided between the bottom of the chassis 5 and the roof 1. The chassis 5 of the positive and negative pantographs is mounted on the roof 1 of the truck through the insulator 8, the chassis 5 itself is not charged, and is connected to the roof of the truck through the insulator 8, adding an extra layer of insulation protection, thereby improving the safety of the entire pantograph relative to the vehicle.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be modified without departing from the spirit or scope of the present invention. Thus, the present invention will not be limited to the embodiments shown herein but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A positive and negative pole pantograph, characterized in that:

   It comprises a base frame (5), a positive electrode power receiving component (2) and a negative electrode power receiving component (3);

   The positive electrode power receiving component (2) and the negative electrode power receiving component (3) are both mounted on the base frame (5);

   The positive electrode power receiving assembly (2) comprises a positive electrode bow (21), a positive electrode upper arm (22), a positive electrode lower arm (23) and a positive electrode rod mechanism (24) for adjusting the height of the positive electrode bow (21);

   The lower end of the positive electrode upper arm (22) is hinged to the upper end of the positive electrode lower arm (23), the upper end of the positive electrode upper arm (22) is connected to the positive electrode bow (21), and the lower end of the positive electrode lower arm (23) is mounted on the base frame (5);

   The negative electrode power receiving assembly (3) comprises a negative electrode bow (31), a negative electrode upper arm (32), a negative electrode lower arm (33) and a negative electrode rod mechanism (34) for adjusting the height of the negative electrode bow (31);

   The lower end of the negative pole upper arm (32) is hinged to the upper end of the negative pole lower arm (33), the upper end of the negative pole upper arm (32) is connected to the negative pole bow (31), and the lower end of the negative pole lower arm (33) is mounted on the base frame (5);

   A torsion limiting device (6) is provided between the negative electrode lower arm (33) and the positive electrode lower arm (23);

   The width of the positive pole bow (21) and the negative pole bow (31) is smaller than the distance between the centers of the positive pole bow (21) and the negative pole bow (31).
2. The positive and negative pantograph according to claim 1 is characterized in that:

   The positive lower arm (23) is rotatably mounted on the base frame (5) via a positive cross bar (25), and the negative lower arm (33) is rotatably mounted on the base frame (5) via a negative cross bar (35). The axes of the positive cross bar (25) and the negative cross bar (35) are located on a straight line, and a torsion limiting device (6) is provided at one end of the positive cross bar (25) and one end of the negative cross bar (35).
3. The positive and negative pantograph according to claim 2 is characterized in that:

   The torsion limiting device (6) comprises a positive limit block (61) and a negative limit block (62), wherein the positive limit block (61) is connected to one end of the positive pole cross bar (25), and the negative limit block (62) is connected to one end of the negative pole cross bar (35), and the positive limit block (61) and the negative limit block (62) are respectively provided with mutually meshing teeth (63) along the circumference of the positive pole cross bar (25) and the circumference of the negative pole cross bar (35), and a distance is left between the teeth (63). Leave.
4. The positive and negative pantograph according to claim 3 is characterized in that:

   Positive pole bow angles (26) are provided on both sides of the positive pole bow (21), and negative pole bow angles (36) are provided on both sides of the negative pole bow (31), the lowest end of the positive pole bow angle (26) is at a height h from the highest point of the positive pole bow (21) in the vertical direction, and the lowest end of the negative pole bow angle (36) is at a height h from the highest point of the negative pole bow (31) in the vertical direction.
5. The positive and negative pantograph according to claim 4 is characterized in that:

   The distance between the pair of teeth (63) can limit the maximum angle of mutual twisting of the positive pole cross bar (25) and the positive pole cross bar (25) to D°, and the maximum height difference between the top of the positive pole upper arm (22) and the top of the negative pole upper arm (32) is C; C is less than or equal to h.
6. The positive and negative pantograph according to claim 5 is characterized in that:

   The base is provided with a bow raising device (7);

   The positive pole rod mechanism (24) comprises a positive pole lower pull rod (242) and a positive pole upper pull rod (241), the positive pole lower pull rod (242) is hinged on the bow lifting device (7), and the upper end of the positive pole lower pull rod (242) is hinged to the lower end of the positive pole upper arm (22);

   The lower end of the positive electrode upper pull rod (241) is hinged to the positive electrode lower arm (23), and the upper end of the positive electrode upper pull rod (241) is hinged to the middle part of the positive electrode bow (21).
7. The positive and negative pantograph according to claim 6 is characterized in that:

   The negative pole rod mechanism (34) comprises a negative pole lower pull rod (342) and a negative pole upper pull rod (341), wherein the negative pole lower pull rod (342) is hinged on the bow lifting device (7), and the upper end of the negative pole lower pull rod (342) is hinged to the lower end of the negative pole upper arm (32);

   The lower end of the negative pole upper pull rod (341) is hinged to the negative pole lower arm (33), and the upper end of the negative pole upper pull rod (341) is hinged to the middle part of the negative pole bow (31).
8. The positive and negative pantograph according to claim 7 is characterized in that:

   The positive pole bow angle (26) and the negative pole bow angle (36) are both made of insulating material.
9. The positive and negative pantograph according to claim 8 is characterized in that:

   The bow lifting device (7) is made of insulating material.
10. An electric vehicle, characterized in that:

    The positive and negative pantographs as claimed in any one of claims 1 to 9 are installed on the roof (1).

    The base frame (5) is installed on the vehicle roof (1), and an insulator (8) is provided between the bottom of the base frame (5) and the vehicle roof (1).