CN111660819A

CN111660819A - Pantograph for track traffic

Info

Publication number: CN111660819A
Application number: CN202010611708.6A
Authority: CN
Inventors: 巴永林; 山田浩二; 纪刚; 孔祥斌
Original assignee: Chengdu Yonggui Dongyang Rail Transit Equipment Co ltd
Current assignee: Chengdu Yonggui Dongyang Rail Transit Equipment Co ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2020-09-15
Anticipated expiration: 2040-06-30
Also published as: CN111660819B

Abstract

The invention discloses a pantograph for track traffic, and relates to the technical field of pantograph of electric vehicles. The invention comprises a base, a lifting arm and a bow, wherein the upper end of the lifting arm is connected with a micro-motion bow, a central rotating shaft at the lower end of the lifting arm is rotatably arranged on the base, and a spring bow lifting device and a bow lowering device which drive the central rotating shaft to rotate are arranged between the central rotating shaft and the base; the micro-motion bow comprises a bow support, an air bag spring and a carbon sliding plate assembly, wherein the carbon sliding plate assembly is arranged on the bow support through the air bag spring, and a guide device for guiding the lifting direction of the carbon sliding plate assembly is arranged between the bow support and the carbon sliding plate assembly. The air bag spring is matched with the guide device in the bow head structure, the spring bow lifting device is adopted to provide a bow lifting force, an air source is not needed in the operation process, and the buffering performance, the current collection stability and the following performance of the bow head and the lifting arm are improved.

Description

Pantograph for track traffic

Technical Field

The invention relates to the technical field of electric vehicle pantographs, in particular to a pantograph for rail transit.

Background

Urban rail vehicles for cities mainly comprise subways, light rails or trams and the like, and the vehicles are powered by contacting a pantograph lifting the top of the vehicles with a contact net when running. The pantograph head is an important component of the pantograph, is a component of the pantograph, is in contact with a contact network, has poor working conditions, and directly determines the current collection quality and reliability of the pantograph according to the performance of the pantograph head.

The chinese patent application No. 201120097224.0 discloses a pantograph for a main locomotive, which is controlled to ascend and descend by a double-airbag pantograph lifting device. The double-air-bag pantograph lifting device comprises a connecting plate, a steel wire rope assembly, a pantograph lifting air bag, an adjusting plate and a butterfly seat; the two bow-lifting air bags are arranged on the underframe; one end of the connecting plate is hinged with the bottom frame, and the other end of the connecting plate is fixed on the butterfly seat; one end of the steel wire rope assembly is fixed on the butterfly seat, and the other end of the steel wire rope assembly is fixed on the lower arm rod; the lower end of the butterfly seat is connected with the bow-lifting air bag, the left end of the butterfly seat is connected with the connecting plate, and the lower end of the bow-lifting air bag is connected with the underframe; the adjusting plate is fixed on the lower arm rod. The air bag type pantograph is provided with pantograph lifting power by a double-air bag pantograph lifting device, wherein lifting power provided by air supply expansion of a pantograph lifting air bag is transmitted to a lower arm rod through a steel wire rope assembly and an adjusting plate to complete pantograph lifting; the pantograph lifting air bag exhausts and contracts, the lifting force disappears, and the pantograph is lowered under the action of self weight.

The existing pantograph has the following problems: 1) the pantograph has poor follow-up performance and stability, the buffering capacity of a pantograph head structure is limited, the pantograph lifting device and the pantograph falling device cannot form a pantograph structure with mutual damping, the pantograph generates larger inertia force when being impacted by a contact network, the contact network is easy to rebound and impact, a pantograph head sliding plate cannot be quickly attached to the contact network, the current collection stability and follow-up performance are reduced, and the sliding plate is easy to wear; 2) the pantograph is lifted by the pantograph lifting air bag, and when the air source works abnormally and the air pressure is insufficient or no air pressure exists, the pantograph is off the net or is in a non-lifting and non-lowering state, so that the troubleshooting difficulty is improved; 3) the pantograph is mainly dependent on the dead weight of the pantograph, the pantograph lifting device and the pantograph lowering device cannot form a pantograph structure with mutual damping, the control precision of the pantograph lifting device is limited, and phenomena of net flushing by the pantograph lifting device and roof smashing by the pantograph lifting device are easy to occur.

Disclosure of Invention

The invention aims to: to current pantograph followup nature and the relatively poor problem of current collection flow stability, provide a pantograph for track traffic, use gasbag spring and guider to cooperate in the bow structure, improve the collection flow stability and the followup nature of bow after being strikeed, adopt spring to rise the bow device and provide and rise bow force, the operation in-process need not the air supply, and keep the shock-absorbing capacity of lifing arm, further improve the collection flow stability and the followup nature of pantograph.

The technical scheme adopted by the invention is as follows:

the pantograph for track traffic disclosed by the invention comprises a base, a lifting arm and a micro-motion bow, wherein the upper end of the lifting arm is connected with the micro-motion bow, a central rotating shaft at the lower end of the lifting arm is rotatably arranged on the base, and a spring pantograph lifting device and a spring pantograph lowering device which drive the central rotating shaft to rotate are arranged between the central rotating shaft and the base; the micro-motion bow comprises a bow support, an air bag spring and a carbon sliding plate assembly, wherein the carbon sliding plate assembly is installed on the bow support through the air bag spring, and a guide device for guiding the lifting direction of the carbon sliding plate assembly is arranged between the bow support and the carbon sliding plate assembly. Due to the arrangement, the air bag spring and the guide device are matched to effectively control the carbon sliding plate assembly to slowly and slightly descend when the carbon sliding plate assembly is pressed, the impact force of a contact net is absorbed, the carbon sliding plate assembly slowly and slightly ascends when the carbon sliding plate assembly leaves the net, the impact force generated when the carbon sliding plate assembly contacts the net again is reduced, and the following performance and the current collection stability of the carbon sliding plate are obviously improved. And the carbon sliding plate assembly is limited by the guide device to move along the axis direction of the air bag spring, the posture of the carbon sliding plate assembly relative to the horizontal plane is kept unchanged in the lifting process, the change of the windward area and the wind resistance is avoided, and the current collection stability can be further improved.

Further, the pantograph device is a pantograph cylinder which has damping buffer force formed by exhaust throttling in the extension stroke and the return stroke of the piston. Due to the arrangement, when the bow is lifted, the spring bow lifting device provides the bow lifting power, and the bow lowering cylinder becomes the bow lifting damping; when the bow is lowered, the bow lowering cylinder provides bow lowering power, and the spring bow raising device becomes bow lowering damping. Meanwhile, the intake and exhaust throttling can form damping buffer force when the intake and exhaust of the bow-reducing cylinder occur, so that the bow-reducing process is obviously stopped. Therefore, the lifting bow driving structure of the buffering lifting type pantograph is simple in design, easy to assemble and maintain and capable of effectively controlling manufacturing and assembling cost.

Furthermore, the pantograph-descending cylinder is a pre-shrinking single-action cylinder, and a piston rod of the pantograph-descending cylinder is restored and retracted through the acting force of the spring pantograph-ascending device. The bow lowering cylinder is a pre-shrinking single-action cylinder, pressure gas is introduced during bow lowering to push out the piston rod so as to drive the bow lowering, and gas is exhausted during bow raising and is reset under the acting force of the spring bow raising device, so that gas supply is not needed during the operation of the railway vehicle.

Furthermore, the inner chamber of the pantograph-reducing cylinder is divided into a rod chamber and a rodless chamber through a piston, the rod chamber is communicated with the atmosphere through a flow limiting hole B, the rodless chamber is communicated with a throttling gas circuit through a flow limiting hole A, and the flow limiting hole A, the flow limiting hole B and the throttling gas circuit are matched to form exhaust throttling. Due to the arrangement, in the moving process of the piston, the rodless cavity and the rod cavity alternately perform air inlet and exhaust through the flow limiting hole A and the flow limiting hole B respectively, the flow limiting hole A and the flow limiting hole B perform speed limiting to form air inlet and exhaust throttling, so that air pressure difference which hinders the movement of the piston is formed between the two cavities of the pantograph-reducing cylinder, and damping buffer force is formed at the exhaust side of the pantograph-reducing cylinder; the damping buffer force is gradually reduced along with the exhaust of the exhaust side and the intake of the intake side until the gas pressure of the rodless cavity and the rod cavity enters a balanced state, the piston starts to move under the action of resultant force, the damping buffer force tends to be close to a stable value, and the piston moves from acceleration to constant speed. Especially, the obvious pause phenomenon exists in the process of lowering the bow.

Furthermore, a pantograph-lowering transmission plate is installed on the central rotating shaft, the roller is rotatably installed on the pantograph-lowering transmission plate, and a piston rod of the pantograph-lowering cylinder is in push-press fit with the roller. Due to the arrangement, the piston rod of the bow-reducing cylinder is in contact-type push-press fit with the transmission plate assembly, sliding friction between the piston rod and the transmission plate assembly is converted into rolling friction by the aid of the rollers, and abrasion can be effectively reduced.

Further, a bow locking device used for locking and unlocking the bow in cooperation with the bow at the bow falling stop point is installed on the base.

Furthermore, the bow locking device comprises a bow fastener movably arranged on the base, a bow lifting unlocking device for driving the bow fastener to move and unlock, and a latch hook spring for driving the bow fastener to reset and cooperatively lock the bow. Due to the arrangement, the pantograph head locking device is matched with the pantograph lifting device to enable the pantograph to have the characteristic of non-lifting and lifting, and no matter whether the pantograph lifting device and the pantograph lifting unlocking device work normally or not, the pantograph only has two working states of keeping a pantograph lifting state and a pantograph lifting state, so that the fault of the pantograph lifting is conveniently eliminated and solved, and the emergency response speed is improved for operators.

Further, the guide device guides the carbon sliding plate assembly to lift along the axial direction of the air bag spring; the guide device comprises a guide table and a sliding piece, the guide table is installed on the bow head support, a guide groove for clamping the sliding piece is formed in the guide table, the upper end of the sliding piece is fixedly connected with the carbon sliding plate assembly, a limiting pin is detachably installed at the lower end of the sliding piece, and the limiting pin is matched with the guide table to limit the expansion range of the air bag spring. Due to the arrangement, the independent guide device guides and limits, so that the carbon sliding plate assembly has more stable micromotion and the service life of the air bag spring is prolonged.

Furthermore, a transmission cam is installed on the central rotating shaft, a chain for transmission connection is arranged between the movable end of the spring pantograph device and the transmission cam, and the fixed end of the spring pantograph device is installed on the base. Due to the structural arrangement, the spring pantograph device is connected with a chain type transmission mechanism consisting of a chain, a transmission part and the like, so that the mechanical property is good, and the stability is strong; the working surface of the chain is attached to the cambered surface of the transmission part when the spring pantograph device is stretched, so that sliding friction hardly occurs, the service lives of the chain and the transmission part are effectively prolonged, and the failure rate is reduced; in addition, the posture is kept by using the tension of the spring pantograph lifting device when the pantograph is lifted, the pantograph lowering device provides pantograph lowering power, the energy consumption is reduced, and the control precision of pantograph lowering is improved.

Furthermore, the lifting arm comprises an upper arm part, a balance rod, a lower arm part and a connecting shaft rod, the micro-motion bow, the upper arm part, the lower arm part and the base are sequentially and rotatably connected, two ends of the balance rod are respectively rotatably connected with the micro-motion bow and the lower arm part, and two ends of the connecting shaft rod are respectively rotatably connected with the base and the upper arm part.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that: compared with the prior art, the carbon sliding plate assembly is limited to perform small-amplitude buffering lifting in the plumb direction after being impacted by a contact net by adopting a micro-motion adjusting scheme of combining an air bag spring with a guide device, has a good absorption effect on the impact force of the contact net, can quickly recover the following state, fixes the lifting posture of the carbon sliding plate assembly to reduce the influence of wind resistance change, improves the stability of the current receiving, and ensures that the carbon sliding plate assembly has lower off-line rate in two aspects of lifting force and following performance; the spring pantograph lifting device provides pantograph lifting power, the pantograph lowering cylinder provides pantograph lowering power, meanwhile, the damping buffer force on the exhaust side of the pantograph lowering cylinder becomes damping in the pantograph lifting process, and the acting force of the spring pantograph lifting device becomes damping in the pantograph lowering process, so that the spring pantograph lifting device and the pantograph lowering cylinder alternately exchange as power and damping, the structural design is simplified, and the design and assembly cost is reduced; the bow lowering cylinder is communicated with the atmosphere to exhaust in the running process of the vehicle, so that the bow raising can be realized by leading the acting force of the spring bow raising device, and gas circuit gas supply is not needed in the running process of the vehicle; the bow lifting action of firstly quickly, then buffering and then uniformly ascending can be realized through the matching of the spring bow lifting device and the throttling gas circuit; the bow lowering action of firstly quickly, then pausing and then uniformly descending can be realized through the matching of the bow lowering cylinder device and the throttling gas circuit; the control air return valve can adjust the bow raising speed, the control pressure gas exhaust speed can adjust the bow lowering speed, and the stability and controllability are high; set up the cooperation bow on the base and carry out the bow locking means who rises the bow unblock and fall the bow locking, no matter fall the bow cylinder and rise the air supply of bow unblock cylinder and whether normally work, the pantograph all only exists and keeps rising the bow state and keep falling two operating condition of bow state, has the characteristics that the non-lift is fallen promptly, and this characteristics make the lift bow detecting system of pantograph can further simplify to be convenient for get rid of and solve the lift bow trouble, help operating personnel improve emergent response speed.

Drawings

Fig. 1 and 2 are schematic perspective views of a pantograph for rail transit according to an embodiment of the present invention;

FIG. 3 is a top view of a track-bound pantograph according to an embodiment of the present invention;

FIG. 4 is a front view of a rail transit pantograph in an embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along line C-C of FIG. 4 in accordance with the present invention;

FIG. 6 is a cross-sectional view taken along line D-D of FIG. 4 in accordance with the present invention;

FIG. 7 is a schematic view of the carbon slide assembly of the micro motion pantograph assembled with the pantograph carriage according to an embodiment of the present invention;

FIG. 8 is a front view of a micro-motion bow according to an embodiment of the present invention;

FIG. 9 is a schematic perspective view of a balance base according to an embodiment of the present invention;

FIG. 10 is a schematic perspective view of an embodiment of a bow locking mechanism according to an embodiment of the present invention;

FIG. 11 is a cross-sectional view of one embodiment of a bow locking mechanism in an embodiment of the present invention;

the labels in the figure are: 10-a base; 20-a lifting arm; 30-micro-motion bow; 40-a pantograph lowering device; 50-spring pantograph means; 60-bow locking means; 70-a bump stop; 80-a sensing device; 210-an upper arm portion; 220-lower arm portion; 230-a balance bar; 240-coupling rod; 211-upper arm lever; 212-a cross-bar; 221-a central rotating shaft; 222-lower arm lever; 223-a roller; 224-a pantograph lowering drive plate; 310-carbon slide plate group; 320-a carbon sled mount; 330-balance assembly; 340-day well tubing; 350-sheep horn; 360-balanced mounting plate; 370-upper arm mounting plate; 331-balance seat; 332-balloon spring; 333-guide table; 334-elastic buffer pads; 335-a guide groove; 336-a slide; 337-a limit pin; 338-spring carrier; 401-cylinder body; 402-front end cap; 403-rear end cap; 404-a piston; 405-a piston rod; 406-ram; 407-rodless cavity; 408-a rod cavity; 409-restriction orifice A; 410-restricted orifice B; 411-high pressure gas escape path; 412-air intake and return path; 413-pneumatic valve; 414-air return valve; 415-main path; 511-a spring body; 512-support rods; 513-hooks; 514, 515-connecting piece; 520-a drive cam; 530-a chain; 610-a bow fastener; 620-raise bow unlocking device; 630-shackle springs; 640-a fixed plate; 611-a hook portion; 612-a handle; 613-a first limiting part; 614-second limiting part; 615-a third limiting part; m-spring pantograph device fixed end; n-spring pantograph device movable end.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The pantograph for rail transit disclosed in the present embodiment is described with reference to fig. 1 to 11, and includes a base 10, a lifting arm 20 and a micro-motion bow 30, wherein the micro-motion bow 30 is connected to an upper end of the lifting arm 20, a central rotating shaft 221 at a lower end of the lifting arm 20 is rotatably installed on the base 10, and a spring pantograph device 50 and a pantograph device 40 for driving the central rotating shaft 221 to rotate are disposed between the central rotating shaft 221 and the base 10.

The micro-motion bow 30 comprises a bow support, an air bag spring 332 and a carbon slide assembly, the carbon slide assembly is mounted on the bow support through the air bag spring 332, and a guide device for guiding the lifting direction of the carbon slide assembly is arranged between the bow support and the carbon slide assembly. Specifically, as shown in fig. 7 and 8, the cavels 350 are symmetrically installed at two ends of the bow support, the sprung structure is simplified into a carbon sliding plate assembly, the weight of the sprung structure is reduced, the current collection stability is improved, and meanwhile, the airbag spring 332 cooperates with the guide device to form micro-motion buffering lifting in the fixed direction, so that the current collection stability and the following performance are further improved.

Optionally, the bow head support comprises a detachable raise pipe 340 and two raise seats 331, and the two raise seats 331 are symmetrically installed at two ends of the raise pipe 340 in the axial direction. In a top view, two sheepskins 350 are respectively arranged on the balance bases 331 at two ends of the raise pipe 340 along the axial extension direction of the raise pipe 340. As shown in fig. 9, the balance seat 331 includes a base body connected to the raise pipe 340 and wing portions symmetrically disposed at both sides of the base body, the two wing portions symmetrically extend to both sides of the raise pipe 340 along a direction parallel to a radial direction of the raise pipe 340, the wing portions of the balance seat 331 at the same side of the raise pipe 340 form a supporting surface for supporting the carbon slide assemblies, and at least one carbon slide assembly is respectively mounted at both sides of the raise pipe 340. The supporting surface is parallel to the axis of the patio pipe 340, the axis of the air bag spring 332 is perpendicular to the supporting surface, under the condition that the patio pipe 340 is kept horizontal, the upper surface of the carbon sliding plate assembly, which is in contact with a contact net, is parallel to the horizontal plane, the supporting surface drives the carbon sliding plate to lift along the plumb direction, and the carbon sliding plate assembly keeps a posture in the micro-motion adjusting process; the carbon slide plate assembly is arranged along the direction parallel to the axis of the patio pipe 340, and eccentric wear is avoided.

The guiding device is installed between the carbon sliding plate assembly and the balance base 331, and plays a role in limiting the lifting direction and the lifting amplitude in the process that the air bag spring 332 drives the carbon sliding plate assembly to lift. Optionally, the guiding device includes a guiding table 333 and a sliding member 336, wherein the guiding table 333 and the balance 331 are preferably configured as an integral structure, the guiding table 333 is provided with a guiding groove 335, the sliding member 336 is snapped into the guiding groove 335, the upper end of the sliding member 336 is fixedly connected to the carbon slider assembly, and the sliding member 336 slides along the guiding groove 335 to limit the carbon slider assembly to reciprocate along the axial direction of the airbag spring 332. The sliding member 336 cooperates with the guide table 333 to guide the carbon slide assembly up and down in the plumb direction while the carbon slide assembly remains horizontal. Optionally, a limit pin 337 is disposed at an end of the sliding member 336 far from the carbon sliding plate assembly, that is, the lower end of the sliding member 336 is provided with the limit pin 337, when the carbon sliding plate assembly is pressed down, the air bag spring 332 enters a contraction stroke, the upper end of the guide table 333 abuts against the bottom of the carbon sliding plate assembly, when the carbon sliding plate assembly is off-grid, the air bag spring 332 enters an extension stroke, and the lower end of the guide table 333 abuts against the limit pin 337, so that the limit pin 337 and the guide table 333 are matched to limit the expansion and contraction amplitude of the air bag spring 332.

In order to further improve the following performance and the power receiving stability, an elastic cushion 334 is optionally installed at the upper end and the lower end of the guide table 333, and the elastic cushion 334 performs deceleration buffering at the end of the contraction stroke and the end of the extension stroke of the airbag spring 332, respectively. Specifically, at the end of the contraction stroke of the airbag spring 332, the carbon sliding plate assembly is pressed to descend to be separated from the net, and the elastic cushion 334 at the lower end of the guide table 333 is in butt joint with the limit pin 337 at the end of the contraction stroke of the airbag spring 332; at the end of the extension stroke of the bladder spring 332, the carbon slide assembly is lifted off-line, and the resilient cushion 334 at the upper end of the guide table 333 is brought into abutting engagement with the carbon slide assembly at the end of the extension stroke of the bladder spring 332.

To facilitate removal and replacement of the carbon skid, the carbon skid assembly optionally includes a carbon skid mounting table 320 and a carbon skid set 310, wherein the carbon skid set 310 is removably mounted to the carbon skid mounting table 320. Spring brackets 338 are symmetrically provided on both sides of the carbon sled mount 320 in the width direction for connecting the air bag springs 332.

Optionally, the airbag spring 332 specifically includes a rigid spring and an airbag, the airbag is wrapped around the rigid spring, and a flow limiting hole formed in the airbag limits the air exhaust speed and the air intake speed of the air in the airbag, and has the characteristic of expansion and contraction in a buffering manner. When the bow head is impacted, the rigid spring is compressed, and the air displacement of the air in the air bag is limited, so that the air bag can act to absorb most impact force when the rigid spring does not reach a balance point; when the bow head is separated from the net wire, the rigid spring is stretched, the air inflow into the air bag is limited, and when the rigid spring does not reach a balance point, the air bag can generate an effect of reducing the impact force of the bow head on the net wire as much as possible.

Optionally, the pantograph device 40 is a pantograph cylinder having a damping force formed by exhaust throttling on both the extension stroke and the return stroke of the piston 404. Specifically, the spring pantograph 50 overcomes the damping buffer force generated by the intake and exhaust throttling of the pantograph cylinder to drive the pantograph, and the pressure gas introduced into the pantograph cylinder overcomes the damping buffer force and the acting force of the spring pantograph 50 to push out the piston rod 405 to drive the pantograph. The pantograph-lowering cylinder is provided with an air inlet and outlet throttle, so that the pantograph-lowering cylinder has damping buffering force (exhaust side pressure) on the exhaust side in both the pantograph-raising process and the pantograph-lowering process, the spring pantograph-raising device 50 overcomes the damping buffering force on the exhaust side of the pantograph-lowering cylinder to drive the pantograph-raising, and the pressure gas introduced into the pantograph-lowering cylinder overcomes the damping buffering force and the acting force of the spring pantograph-raising device 50 to push out the piston rod 405 to drive the pantograph-lowering. As shown in fig. 5, the pressure gas is introduced into the pantograph-lowering cylinder to extend the piston rod 405, and the piston rod 405 drives the central rotating shaft 221 to rotate counterclockwise to lower the lifting arm 20 and the micro-motion pantograph head 30, that is, the pantograph-lowering cylinder provides pantograph-lowering power; the spring pantograph 50 drives the central rotating shaft 221 to rotate clockwise to lift the lifting arm 20 and the micro-motion pantograph 30, that is, the spring pantograph 50 provides pantograph lifting power. Further, in the pantograph descending process, the spring pantograph 50 continuously provides acting force for enabling the spring pantograph 221 to rotate clockwise to the central rotating shaft 221, the acting force of the spring pantograph 50 is pantograph descending resistance, the pressure gas introduced into the pantograph descending cylinder pushes the piston rod 405 to drive the central rotating shaft 221 to rotate anticlockwise, and the pressure gas needs to overcome the damping buffer force on the exhaust side of the pantograph descending cylinder and the acting force of the spring pantograph 50 to drive pantograph descending in the process; in the pantograph lifting process, the pantograph lowering cylinder is linked when the spring pantograph lifting device 50 drives the central rotating shaft 221 to rotate clockwise, and the exhaust side of the pantograph lowering cylinder generates damping buffering force, so that the spring pantograph lifting device 50 needs to overcome the damping buffering force at the exhaust side of the pantograph lowering cylinder to drive the pantograph lifting.

Optionally, the pantograph cylinder is a pre-shrinking single-acting cylinder, and a piston rod 405 of the pantograph cylinder is restored and retracted by the acting force of the spring pantograph device 50. Specifically, the air inlet side of the bow-reducing cylinder is communicated with an air source during bow reduction, and pressure air introduced into the air inlet side pushes the piston rod 405 to extend out and drive the bow reduction; the air inlet side of the pantograph-descending cylinder is communicated with the atmosphere when the pantograph is lifted, and the piston rod 405 is linked to reset and return when the spring pantograph lifting device 50 drives the pantograph to lift. In this embodiment, the external force reset type single-acting cylinder is used as the pantograph lowering cylinder, so that gas supply is not required in the pantograph raising process, and the spring pantograph raising device 50 automatically takes the lead in the pantograph raising process.

Optionally, the inner chamber of the pantograph cylinder is divided into a rod chamber 408 and a rodless chamber 407 by a piston 404, the rod chamber 408 is communicated with the atmosphere through a flow limiting hole B410, the rodless chamber 407 is communicated with a throttling gas circuit through a flow limiting hole a409, and the flow limiting hole a409 and the flow limiting hole B410 are matched with the throttling gas circuit to form exhaust throttling. Specifically, the cylinder block 401 includes at least a cylinder barrel, a front end cap 402 and a rear end cap 403, so that a restriction orifice a409 is preferably provided in the rear end cap 403 and a restriction orifice B410 is preferably provided in the front end cap 402. The piston rod 405 connected to the piston 404 extends out of the cylinder 401 from the mounting hole of the front end cover 402, and the piston 404 and the piston rod 405 are in sealing fit with the cylinder 401. The flow limiting hole A409 and the flow limiting hole B410 are matched with a throttling air path for limiting speed, so that a damping buffering force generated by air inlet and outlet throttling is formed at the exhaust side of the pantograph-descending cylinder, the damping buffering force is greater than the power at the air inlet side of the pantograph-descending cylinder at the initial end of the stroke of the movement of the piston 404, and the damping buffering force gradually decreases along with the exhaust of the exhaust side and tends to a stable value. In the process of raising the pantograph, the air inlet side of the pantograph-lowering cylinder corresponds to the rod cavity 408, the air outlet side of the pantograph-lowering cylinder corresponds to the rodless cavity 407, the pantograph-lowering cylinder is directly or indirectly matched with the flow-limiting hole A409 and the flow-limiting hole B410 for speed limiting, at the beginning of the stroke of the movement of the piston 404, the acting force of the spring pantograph-raising device 50 enables the piston 404 to move towards the exhaust side rodless cavity 407, the exhaust speed of the rodless cavity 407 is limited to enable the rodless cavity 407 to form high pressure, the air inlet speed of the rod cavity 408 is limited to enable the rod cavity 408 to form low pressure, therefore, the air outlet side forms a damping buffer force for blocking the movement of the piston 404, at the moment, the damping buffer force is greater than the power of the air inlet side of the pantograph-lowering cylinder, the power of the air inlet side of the pantograph-lowering; with the exhaust of the rodless cavity 407 and the intake of the rod cavity 408, the gas pressure in the rodless cavity 407 decreases, and the gas pressure in the rod cavity 408 increases, so the damping buffer force gradually decreases until the pressures in the rodless cavity 407 and the rod cavity 408 enter a dynamic balance state, the spring pantograph lifting device 50 overcomes the damping buffer force to lift the pantograph, the damping buffer force tends to a stable value in the pantograph lifting process, and the pantograph lifting speed tends to a constant speed. In the process of lowering the bow, the air inlet side of the bow lowering cylinder corresponds to the rodless cavity 407, the air outlet side of the bow lowering cylinder corresponds to the rod cavity 408, at the beginning of the stroke of the movement of the piston 404, pressure gas introduced into the air inlet side enables the piston 404 to move towards the air outlet side, the air outlet speed of the rod cavity 408 is limited to enable the rod cavity 408 to form high pressure, the air inlet speed of the rodless cavity 407 is limited to enable the rodless cavity 407 to form low pressure, therefore, the air outlet side forms damping buffer force for hindering the movement of the piston 404, at the moment, the damping buffer force is larger than the power of the air inlet side, and the bow lowering process is accelerated and then decelerated or even stopped at the; with the exhaust of the rod chamber 408 and the intake of the rodless chamber 407, the gas pressure in the rod chamber 408 is reduced, and the gas pressure in the rodless chamber 407 is increased, so that the damping buffer force is gradually reduced until the pressures in the rod chamber 408 and the rodless chamber 407 enter a dynamic balance state, the pressure gas overcomes the damping buffer force and the acting force of the spring pantograph-lifting device 50 to lower the pantograph, the damping buffer force tends to a stable value in the pantograph-lowering process, and the pantograph-lowering speed rapidly approaches to a constant speed. It should be noted that the trend of the damping buffering force to the stable value does not mean that the damping buffering force stays at the stable value, but means that the damping buffering force regularly fluctuates in a small amplitude within a predetermined interval range including the stable value.

Optionally, the throttling air path of the pantograph lowering cylinder includes a high-pressure air release path 411 and an air intake and return path 412 which are respectively communicated with the throttling hole a409, the high-pressure air release path 411 and the air intake and return path 412 are connected to the main path 415 through an air pressure valve 413, the high-pressure air release path 411 is communicated with the main path 415 in a one-way manner, and the main path 415 is communicated with the air intake and return path 412 in a one-way manner; the high-pressure air leakage path 411 is provided with an air return valve 414 for adjusting the air exhaust speed of the rodless cavity 407. Specifically, the flow-limiting hole A409 and the flow-limiting hole B410 are matched with the pressure gas inlet speed of the gas inlet and return path 412 to adjust the bow reduction speed, further, the gas inlet speed of the rodless cavity 407 is controlled by the pressure gas inlet speed of the flow-limiting hole A409 and the gas inlet and return path 412, the gas outlet speed of the rod cavity 408 is controlled by the flow-limiting hole B410, and the gas inlet speed of the rodless cavity 407 and the gas outlet speed of the rod cavity 408 comprehensively adjust the extension speed of the piston rod 405; the flow limiting A and the flow limiting hole B410 are matched with an air return valve 414 of a high-pressure air release passage 411 to adjust the pantograph lifting speed, further, the air inlet speed of the rod cavity 408 is controlled by the flow limiting hole B410, the air outlet speed of the rodless cavity 407 is controlled by the flow limiting A and the air return valve 414 of the high-pressure air release passage 411, and the air outlet speed of the rodless cavity 407 and the air inlet speed of the rod cavity 408 comprehensively adjust the return speed of the piston rod 405.

Optionally, the main path 415 is respectively communicated with an air source and the atmosphere through an electromagnetic directional valve; the main path 415 is communicated with the air source when the electromagnetic directional valve is powered on, and the main path 415 is communicated with the atmosphere when the electromagnetic directional valve is powered off. Preferably, the electromagnetic directional valve is a two-position three-way valve. Specifically, the pantograph cylinder in this embodiment switches the communication state of the rodless cavity 407 with the air source and the atmosphere through the electromagnetic directional valve, and except for the pantograph process, the rod cavity 408 and the rodless cavity 407 of the pantograph cylinder are both communicated with the atmosphere.

Optionally, a pantograph drive plate 224 is mounted on the central rotating shaft 221, the roller 223 is rotatably mounted on the pantograph drive plate 224, and the piston rod 405 of the pantograph cylinder is in press fit with the roller 223. Specifically, in the pantograph lifting process, the spring pantograph device 50 drives a driving plate assembly consisting of the pantograph driving plate 224 and the roller 223 to push the piston rod 405 of the pantograph cylinder through the central rotating shaft 221, and the piston rod 405 and the roller 223 move relatively; in the process of lowering the bow, the pressure gas introduced into the bow lowering cylinder enables the piston rod 405 to push and press the roller 223 of the transmission plate assembly, the transmission plate assembly drives the central rotating shaft 221 to rotate, and the piston rod 405 and the roller 223 move relatively. The roller 223 can convert sliding friction into rolling friction, and the matching relationship can effectively prolong the service life of the pantograph-lowering cylinder and the transmission plate component and reduce the failure rate.

Optionally, the fixed end M of the spring pantograph device is detachably fixed on the base 10 by a bolt and a spring bracket, the movable end N of the spring pantograph device is movably connected with a transmission cam 520 arranged on the central rotating shaft 221 by a chain 530, and the transmission cam 520 and the central rotating shaft 221 rotate synchronously. During the process of lifting the bow, the pulling force generated by the contraction of the spring bow lifting device 50 is transmitted to the transmission cam 520 through the chain 530, and the transmission cam 520 is stressed and drives the central rotating shaft 221 to rotate synchronously.

Alternatively, the spring bow 50 may be a tension spring, which may be linearly moved in a telescopic manner along its own axis or may be bent. The spring pantograph 50 comprises a support rod 512 and a spring body 511, wherein one end of the support rod 512 is detachably mounted on the base 10, the other end of the support rod 512 is connected with the spring body 511 through a connecting piece 514 at the fixed end of the spring body 511 and extends into the spring body 511, and the axis of the support rod is coincident with or parallel to the axis of the spring body 511; the link 515 at the free end of the spring body 511 is connected to the chain 530 by a hook 513. Preferably, the distance between the free end of the support rod 512 extending into the spring body 511 and the movable end of the spring body 511 decreases as the spring body 511 contracts, and the free end of the support rod 512 defines the end of the contraction stroke of the spring body 511. Optionally, at least two sets of spring slingers 50 are provided on the base 10, preferably two sets.

Optionally, the chain 530 is flat and is the main transmission element of the pantograph. The chain 530 comprises a plurality of mutually adjacent chain links, which in turn are mutually rotatably connected about mutually parallel axes of rotation. The axis of rotation is parallel to the axis of the central shaft 221 and perpendicular to the axis of the spring bow 50. Preferably, the chain 530 is a plate chain or a roller chain. In order to increase the force bearing area between the chain 530 and the transmission cam 520 and prevent the local pressure from being too large to cause the parts to be worn too fast, the ratio of the width of the chain 530 to the width of the transmission cam 520 is 0.5-2.

Alternatively, the driving cam 520 is the main driving part of the raising bow, and the chain 530 can be guided to be curled/released along the arc of the driving cam 520 during the raising bow and the lowering bow. In the first preferred embodiment of the driving cam 520, the driving cam 520 is a detachable structure, which is convenient for maintenance and replacement; the driving cam 520 includes a cam body and a fixing plate 640, the cam body is connected with the fixing plate 640 by a bolt, so that the driving cam 520 is integrally fixed on the central rotating shaft 221; the cam body has a non-circular arc face. In a second preferred embodiment of the driving cam 520, the driving cam 520 is an integral structure, the cross section of the driving cam 520 is circular, the driving cam is concentrically sleeved on the central rotating shaft 221, and flanges for limiting the chain 530 are disposed at two side edges of the arc surface of the driving cam 520.

In the preferred embodiment, the spring pantograph 50 is disposed at an angle, and the movable end N of the spring pantograph is lower than the fixed end M of the spring pantograph, and the movable end N can be prevented from sagging with gravity by the traction of the chain 530. The arcuate surface of the drive cam 520 preferably engages the chain 530 such that the chain 530 guides the spring bow 50 along the axis of the spring bow 50 without the spring bow free end N bending or lifting up and down. During the extension and retraction of the spring pantograph 50, the extension line of the axis of the spring pantograph 50 is stationary with respect to the base 10, i.e. the fixed end M of the spring pantograph does not rotate and displace, so that the extension line of the axis of the spring pantograph 50 moves with respect to the base 10.

The base 10 is provided with a bow locking device 60 which is used for locking and unlocking at the bow descending dead point by matching with the micro-motion bow 30. Specifically, when the air source of the pantograph cylinder and the power source of the pantograph head locking device 60 are working normally: 1) starting a pantograph lifting process in a pantograph lowering state, starting the pantograph locking device 60 to unlock and release the micro-motion pantograph 30, so that the spring pantograph lifting device 50 can drive the central rotating shaft 221 to rotate so as to drive the pantograph to lift until the pantograph enters a pantograph lifting state, namely a pantograph lifting stop point is reached; 2) when the pantograph descending process is started in the pantograph ascending state, the pantograph descending cylinder overcomes the acting force of the spring pantograph ascending device 50 to drive the central rotating shaft 221 to rotate reversely so as to drive the pantograph descending until the pantograph enters the pantograph descending state, namely, the pantograph descending stop point is reached, and the micro-motion pantograph head 30 is locked at the pantograph descending stop point by matching with the pantograph head locking device 60. When the air source of the pantograph cylinder and/or the power source of the pantograph head locking device 60 work abnormally: 1) starting the pantograph lifting process in the pantograph lowering state, wherein the pantograph head locking device 60 cannot be unlocked due to the abnormal influence of the power source work, and the pantograph keeps the pantograph lowering state; 2) starting a pantograph descending process in a pantograph ascending state, wherein a pantograph descending cylinder cannot drive a pantograph descending cylinder to descend due to abnormal work of an air source, and a pantograph is kept in a pantograph ascending state; 3) in the pantograph lifting process, the pantograph locking device 60 releases the micro-motion pantograph 30, and the pantograph-lowering cylinder has no self-locking function, so that the pantograph continues to lift and keeps a pantograph-lifting state after the power source of the pantograph locking device 60 and/or the air source of the pantograph-lowering cylinder work abnormally; 4) in the pantograph lowering process, the air source of the pantograph lowering cylinder works abnormally, and the pantograph lowering cylinder cannot overcome the acting force of the spring pantograph lifting device 50 to enable the pantograph to return to the pantograph lifting state. Therefore, no matter in normal operation or in abnormal operation of the air source of the pantograph cylinder and/or the power source of the pantograph locking device 60, the pantograph exhibits a non-lifting or non-lifting characteristic, and the rail vehicle cannot be in failure due to non-lifting or non-lifting of the pantograph. On the other hand, a complicated lifting bow detection system and a complicated fault removal system are not required to be designed for the pantograph, the current working state of the pantograph can be reflected only by detecting whether the pantograph is positioned at a pantograph lifting stop point or whether the pantograph is positioned at a pantograph lowering stop point, and an operator can make a quick response to determine whether the emergency device is started to lift or lower the pantograph in an emergency.

Optionally, the bow locking device 60 includes a bow fastener 610 movably mounted on the base 10, a bow-lifting unlocking device 620 for driving the bow fastener 610 to unlock in a moving manner, and a latch hook spring 630 for driving the bow fastener 610 to reset and cooperate to lock the bow. Further, in a specific embodiment, the bow fastener 610 is a locking hook, the locking hook is rotatably installed on the base 10, and a tension spring for resetting is provided between the locking hook and the base 10, and the tension spring enables the locking hook to lock the micro-motion bow 30; as shown in fig. 11, the tension spring can drive the locking hook to rotate counterclockwise and lock the micro-motion bow 30, when the micro-motion bow 30 pushes and presses the locking hook downward, the locking hook rotates clockwise to open and lock the locking hook and the bow, and then the micro-motion bow 30 is reset and locked counterclockwise under the action of the tension spring; the pantograph lifting unlocking device 620 for driving the locking hook to rotate and unlock is fixed on the base 10, and a piston rod 405 or a push rod of the pantograph lifting unlocking device 620 pushes and presses the locking hook to rotate clockwise and unlock the micro-motion pantograph head 30. In another embodiment, the bow fastener 610 is a latch hook movably mounted on the base 10 through a guide rail and a limiting slider, the latch hook is preferably configured to be horizontally translatable, and a tension spring for resetting is disposed between the latch hook and the base 10; the tension spring can drive the lock hook to translate along a first direction and lock the micro-motion bow 30, when the micro-motion bow 30 pushes and presses the lock hook downwards, the lock hook translates along a second direction opposite to the first direction to be opened so that the lock hook is buckled with the micro-motion bow 30, then the lock hook translates along the first direction under the action of the tension spring to reset and lock the micro-motion bow 30, and the first direction is opposite to the second direction; the pantograph lifting unlocking device 620 for driving the locking hook to rotate and unlock is fixed on the base 10, and a piston rod 405 or a push rod of the pantograph lifting unlocking device 620 contracts to pull the locking hook to translate along the second direction and unlock the micro-motion pantograph head 30. The pantograph lifting unlocking device 620 may be a pantograph lifting unlocking cylinder or an electromagnetic release device.

Optionally, the bow clasp 610 locks the bow through the combined force of the spring pantograph 50 and the shackle spring 630. Specifically, spring pantograph 50 cooperates with shackle spring 630 to provide a latching force. When the bow falls to the right position, the bow buckling piece 610 moves and is scratched under the pushing of the micro-motion bow 30, then the bow 30 is buckled by moving in the reverse direction under the driving of the locking hook spring 630, the air source stops supplying air to the bow-falling cylinder, the bow-falling power is cancelled, the micro-motion bow 30 rapidly presses the locking hook upwards under the action of the spring bow lifting device 50 to further lock the micro-motion bow 30, and the bow buckling piece 610 and the micro-motion bow 30 can be effectively prevented from being separated from each other due to reasons such as emergency braking inertia of a railway vehicle.

Optionally, the rotatable locking hook comprises a handle portion 612 and a hook portion 611, one end of the handle portion 612 is movably connected with the elastic resetting device, the other end of the handle portion 612 is in push fit with the unlocking driving device, and the middle section of the handle portion 612 is connected with the base 10 through a pin shaft.

Optionally, a working surface for sliding fit with the bow is arranged at the top of the hook portion 611 of the locking hook, and the working surface is an arc surface or an inclined surface, so that the locking hook rotates along with the bow pushing the working surface. Specifically, the working surface is an inclined surface or an arc surface, and the bow pushes the working surface of the locking hook downwards and generates a normal force perpendicular to the working surface, and the component of the normal force in the horizontal direction enables the locking hook to rotate.

Optionally, a first limiting portion 613 is disposed between the handle portion 612 of the lock hook and the base 10, and the first limiting portion 613 limits a retraction dead point of the tension spring and aligns the hook portion 611 of the lock hook with the micro-motion bow 30. Specifically, the base 10 is provided with a first limiting portion 613, and the first limiting portion 613 is a pin or a bolt capable of adjusting the extension length. The handle 612 or the base 10 of the lock hook is provided with a second limiting part 614, and the second limiting part 614 limits the tension stop point of the tension spring. Specifically, the second position-limiting portion 614 is disposed on the handle portion 612 of the locking hook, and the second position-limiting portion 614 is a cylindrical protrusion or an arc-shaped protrusion, preferably an arc-shaped protrusion.

Optionally, the shank 612 of the shackle is provided with an arcuate projection for push-fitting with the unlocking drive. The arcuate projections are preferably integrally formed with the shackle stem 612. Specifically speaking, along with the rotation of the lock hook, the arc-shaped bulge part enables the unlocking driving device and the arc-shaped bulge part to form rolling fit in the rotation process of the lock hook, and abrasion can be effectively reduced.

Optionally, as shown in fig. 1, the base 10 is provided with a buffer stop 70 for preventing the inching bow 30 from hitting the base 10 along with the descending bow; the bump stop 70 is preferably made of an elastic material. Specifically, there is a time difference between the locking of the pantograph locking device 60 by the micro-motion pantograph 30 and the stopping of the pantograph cylinder to drive the pantograph, and in order to prevent the pantograph from being excessively pressed down and impacting the base 10 during pantograph lowering, the buffering stop 70 is arranged on the base 10 to absorb the impact force of the lowering of the pantograph and limit the lowering. The bump stop 70 may preferably be made of an elastic material.

Optionally, a sensing device 80 for detecting the state of the lifting bow is disposed on the base 10. The sensing device 80 may be one of a passive proximity switch, a vortex proximity switch, a capacitive proximity switch, a hall proximity switch, and an electro-optical proximity switch. Preferably, the sensing device 80 is a capacitive proximity switch, and the sensing device 80 is used for detecting whether the micro-motion head 30 is located at the pantograph dead center. When the pantograph enters a pantograph descending state, the micro-motion pantograph head 30 is positioned at a pantograph descending stop point, and the proximity switch is electrified; when the pantograph enters a pantograph lifting state, the micro-motion pantograph head 30 is positioned at a pantograph lifting dead point, and the proximity switch is powered off.

Optionally, the lifting arm 20 includes an upper arm portion 210, a balance bar 230, a lower arm portion 220, and a connecting shaft 240, the micro-motion bow 30, the upper arm portion 210, the lower arm portion 220, and the base 10 are sequentially and rotatably connected, two ends of the balance bar 230 are respectively rotatably connected to the micro-motion bow 30 and the lower arm portion 220, and two ends of the connecting shaft 240 are respectively rotatably connected to the base 10 and the upper arm portion 210. Specifically, the lifting arm 20 includes an upper arm portion 210, a balance bar 230, a lower arm portion 220 and a connecting shaft rod 240, the connecting shaft rod 240 and the lower arm portion 220 having a central rotating shaft 221 at the lower end thereof are respectively rotatably connected between the base 10 and the upper arm rod 211, and the upper arm portion 210, the lower arm portion 220, the connecting shaft rod 240 and the base 10 form a first planar four-bar linkage; the upper arm 210 and the balance bar 230 are rotatably connected between the lower arm 220 and the bow, respectively, and the upper arm 210, the lower arm 220, the balance bar 230 and the bow form a second planar four-bar linkage. The spring pantograph 50 and pantograph 40 drives the central rotating shaft 221 of the lower arm 220 to rotate, so as to drive the linked first plane four-bar linkage mechanism and the linked second plane four-bar linkage mechanism to move, and realize the lifting of the micro-motion pantograph head 30.

Optionally, the lower arm part 220 includes a central rotating shaft 221, a lower arm bar 222, an arch raising transmission assembly and an arch lowering transmission assembly, the lower end of the lower arm bar 222 is fixedly connected with the central rotating shaft 221, the lower arm bar 222 and the central rotating shaft 221 are arranged in a substantially T shape, and the arch raising transmission assembly and the arch lowering transmission assembly are mounted on the central rotating shaft 221; the upper end of the lower arm bar 222 is hinged with the lower end of the upper arm 210, and the two ends of the connecting shaft bar 240 are hinged with the lower ends of the base 10 and the upper arm 210 respectively.

Optionally, the upper arm 210 is T-shaped, the upper arm 210 includes an upper arm 211 and a cross bar 212 mounted at the upper end of the upper arm 211, and the upper arm 211 and the cross bar 212 are arranged substantially in T-shape; two ends of the cross rod 212 are rotatably connected with an upper arm mounting plate 370 of the patio tube 340, the lower end of the upper arm rod 211 is hinged with the upper end of the lower arm part 220, the lower end of the balance rod 230 is rotatably connected with the upper end of the lower arm part 220, and the upper end of the balance rod 230 is rotatably connected with a balance mounting plate 360 of the patio tube 340. Wherein, the balance bar 230 has an adjusting screw rod with adjustable length, and the balance bar 230 ensures the horizontal state of the bow by adjusting the extending length of the adjusting screw rod.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. The pantograph for rail transit comprises a base (10), a lifting arm (20) and a micro-motion bow (30), wherein the upper end of the lifting arm (20) is connected with the micro-motion bow (30), and a central rotating shaft (221) at the lower end of the lifting arm (20) is rotatably arranged on the base (10), and is characterized in that a spring pantograph lifting device (50) and a pantograph lowering device (40) which drive the central rotating shaft (221) to rotate are arranged between the central rotating shaft (221) and the base (10); the micro-motion bow head (30) comprises a bow head support, an air bag spring (332) and a carbon sliding plate assembly, wherein the carbon sliding plate assembly is installed on the bow head support through the air bag spring (332), and a guide device for guiding the lifting direction of the carbon sliding plate assembly is arranged between the bow head support and the carbon sliding plate assembly.

2. Pantograph for rail transit according to claim 1, characterised in that said pantograph device (40) is a pantograph cylinder having a damping force by exhaust throttling both on the extension stroke and on the return stroke of the piston (404).

3. Pantograph for rail transit according to claim 2, characterised in that the pantograph cylinder is a pre-retraction type single-acting cylinder, the piston (404) rod of which is reset to retract by the action of the spring pantograph (50).

4. The pantograph for rail transit according to claim 2, wherein the inner chamber of the pantograph cylinder is divided into a rod chamber (408) and a rodless chamber (407) by a piston (404), the rod chamber (408) is communicated with the atmosphere through a flow limiting hole B (410), the rodless chamber (407) is communicated with a throttling gas passage through a flow limiting hole A (409), and the flow limiting hole A (409) and the flow limiting hole B (410) are matched with the throttling gas passage to form exhaust throttling.

5. Pantograph for rail transit according to claim 2, characterised in that on said central rotating shaft (221) there is mounted a pantograph-lowering transmission plate (224), on which roller (223) is rotatably mounted the pantograph-lowering transmission plate (224), the piston (404) rod of the pantograph-lowering cylinder being in push-fit with the roller (223).

6. Pantograph for rail transit according to claim 1, characterised in that on said base (10) there are mounted bow locking means (60) for locking and unlocking with a micro-motion bow at the pantograph dead centre.

7. The pantograph for rail transit according to claim 1, wherein the bow locking device (60) comprises a bow fastener (610) movably mounted on the base (10), a pantograph lifting unlocking device (620) for driving the bow fastener (610) to unlock in a moving manner, and a latch hook spring (630) for driving the bow fastener (610) to return and cooperate with the locking bow.

8. The pantograph for rail transit of claim 1, wherein the guide means guides the carbon slide plate assembly to ascend and descend in the axial direction of the air bag spring (332); the guiding device comprises a guiding table (333) and a sliding piece (336), the guiding table (333) is installed on the bow head support, a guiding groove (335) for clamping the sliding piece (336) is formed in the guiding table (333), the upper end of the sliding piece (336) is fixedly connected with the carbon sliding plate assembly, a limiting pin (337) is detachably installed at the lower end of the sliding piece (336), and the limiting pin (337) is matched with the guiding table (333) to limit the expansion amplitude of the airbag spring (332).

9. Pantograph for rail transit according to claim 1, characterised in that on said central rotating shaft (221) there is mounted a transmission cam (520), between the free end (N) of the spring pantograph and the transmission cam (520) there is arranged a chain (530) for transmission connection, and the fixed end (M) of the spring pantograph is mounted on the base (10).

10. Pantograph for rail transit according to claim 1, characterized in that said lifting arm (20) comprises an upper arm (210), a balancing lever (230), a lower arm (220) and a connecting rod (240), said micro-motion head (30), upper arm (210), lower arm (220) and base (10) being rotatably connected in sequence, said balancing lever (230) being rotatably connected at its two ends to said micro-motion head (30) and lower arm (220), respectively, and said connecting rod (240) being rotatably connected at its two ends to said base (10) and upper arm (210), respectively.