CN115366931A - Wheel-rail system and rail transit vehicle traction/braking force distribution method - Google Patents

Abstract

The invention discloses a wheel-rail system and a method for distributing traction force/braking force of a rail transit vehicle, wherein the wheel-rail system comprises a rail and a wheel pair moving on the rail; a roller running on the track is arranged between two wheels on at least one side of each two adjacent wheel pairs; the center of the roller is connected with a first supporting seat arranged on the steering frame through a bearing; and the first supporting seat is provided with a driving device for driving the roller and/or a braking device for adjusting the rotating speed of the roller. The invention avoids the wheel set slipping phenomenon under any condition, avoids the polygonal abrasion of the wheel set and prolongs the service life of the wheel set.

Description

Wheel-rail system and rail transit vehicle traction/braking force distribution method

technical field

The invention relates to the technical field of rail transit, in particular to a wheel-rail system and a traction force/braking force distribution method for rail transit vehicles.

Background technique

At present, rail transit vehicles are not equipped with wheel-rail adhesion coefficient detection devices, and the track conditions cannot be known. The most favorable control strategy for vehicle operation can only be obtained through the traction system and the anti-skid system of the braking system. At present, these anti-skid control methods cannot allow the vehicle to make full use of the wheel-rail adhesion coefficient, give full play to the traction force and braking force, and can only check the calculation of traction force and braking force under the assumed adhesion coefficient.

The existing technology can only detect the skidding or idling after the vehicle actually skids or idling, and then adjusts and slows down the slipping or idling of the wheel set through the control system. There is a risk of wheel scratches, and even vehicle running in extreme cases. out of control problem.

Contents of the invention

The technical problem to be solved by the present invention is to provide a wheel-rail system and a traction force/braking force distribution method for rail transit vehicles to obtain the real adhesion coefficient of the running track in real time.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a wheel-rail system, including a track and a wheel set moving on it; the wheel set is fixedly connected to the bogie frame through a series of springs; Rollers running on the track are arranged between two wheels on at least one side of each wheel pair; the center of the rollers is connected with the first support seat arranged on the bogie frame through a bearing; the first support The seat is provided with a driving device for driving the roller and/or a brake device for adjusting the rotation speed of the roller.

The present invention is provided with rollers that can run on the track, and the air spring can apply vertical pressure to the rollers, allowing the rollers to run with the vehicle, and the braking device can adjust the linear creep speed of the rollers. By adjusting the linear creep speed of the rollers, it can be converted The tangential traction force and tangential braking force at the contact point between the roller and the track are obtained, and then the adhesion coefficient between the roller and the track is obtained, which realizes the real-time detection of the real adhesion coefficient of the running track.

According to actual use requirements, rollers running on corresponding tracks can be arranged between two wheels on both sides of two adjacent wheel pairs.

In the present invention, the bearing is connected to the first supporting seat through a connecting rod and an air spring in sequence.

In the present invention, in order to facilitate the collection of required data, the upper end of the air spring is connected to the first support base, and the lower end is connected to the second support base; the second support base is provided with a pressure sensor.

The upper end of the air spring is connected to the first support base, and the lower end is connected to the second support base; the second support base is provided with a pressure sensor. The pressure sensor can accurately detect the vertical pressure of the roller in real time.

A range finder is arranged on the second support base. The rangefinder accurately measures the radius of the small steel wheel by measuring the height between the second support seat and the rail surface.

The brake device includes a brake caliper, the brake caliper is in contact with the roller, and the brake caliper communicates with the air cylinder provided on the first support base.

The pair of rollers is arranged on the first bogie frame of the head car. Obtain the adhesion coefficient more accurately.

The present invention also provides a method for utilizing the above-mentioned wheel set system to realize traction/braking force distribution of rail transit vehicles. The method includes: calculating the maximum traction force and/or maximum braking force according to the adhesion coefficient, controlling the vehicle traction force and braking force, and making the vehicle The traction force is less than the maximum traction force, and the vehicle braking force is less than the maximum braking force. The invention calculates the maximum traction force and the maximum braking force according to the adhesion coefficient, and can adjust the traction force and braking force of the vehicle through the control system before the wheels slide or idle, which prevents the wheel from scratching, avoids the vehicle running out of control, and greatly guarantees Driving safety.

In the present invention, the specific implementation process of calculating the maximum traction force and/or the maximum braking force according to the adhesion coefficient includes:

Control the creep speed of the roller to be greater than the running speed of the vehicle, and calculate the tangential traction force F1 at the contact point between the roller and the track; when the creep speed of the roller reaches the set threshold value, according to the vertical pressure Fn applied to the roller by the air spring , The tangential traction force F1 calculates the first adhesion coefficient μ1 between the roller and the track;

Use the brake caliper to adjust the clamping force on the roller, so that the creep linear speed of the roller is lower than the running speed of the vehicle, and convert the tangential braking force F2 at the contact point between the roller and the track; when the creep linear speed of the roller reaches the set When setting the threshold value, calculate the second adhesion coefficient μ2 between the roller and the track according to the vertical pressure Fn and tangential braking force F2 exerted by the air spring on the roller;

According to the first adhesion coefficient μ1 and the second adhesion coefficient μ2, the maximum traction force and the maximum braking force that the vehicle can exert when running on the current track are respectively calculated.

After real-time detection of the adhesion coefficient, the present invention calculates the maximum traction force and braking force that the vehicle can exert according to the adhesion coefficient, and correspondingly controls the vehicle traction force and braking force within the range of the maximum traction force and maximum braking force, so as to actively prevent wheel idling and skidding, Wheel scratches are avoided, and the service life of the wheel set is improved.

In order to further improve the traction force/braking force distribution accuracy, in the present invention, before controlling the creep speed of the roller to be greater than the running speed of the vehicle, it also includes:

1) When the air spring is inflated to the target value, the driving device/braking device outputs traction/braking force;

2) Judging whether the linear creep speed of the roller reaches the set threshold value, if so, the driving device/braking device locks the traction force/braking force, and returns to step 1) after the set time period; otherwise, returns to step 1) .

Controlling the traction force and braking force of the vehicle so that the traction force of the vehicle is less than the maximum traction force, and after the braking force of the vehicle is less than the maximum braking force, it also includes:

Judging whether to activate the idling protection, if so, adjusting the threshold value, and returning to step 1); judging whether to activate the coasting protection, if so, adjusting the threshold value, returning to step 1).

The invention can avoid the idling or slipping of the wheel set to the greatest extent, avoid the polygonal wear of the wheel set, and greatly improve the service life of the wheel set.

Compared with the prior art, the present invention has the beneficial effects that: the present invention can detect the track adhesion coefficient in real time; make full use of the track adhesion coefficient under any track conditions, improve the control accuracy and level of the vehicle; avoid any situation The slipping phenomenon of the wheel set avoids the polygonal wear of the wheel set and improves the service life of the wheel set.

Description of drawings

Fig. 1 is the device structural diagram of embodiment 1 of the present invention;

Fig. 2 is the structural diagram of the device of Embodiment 2 of the present invention;

Fig. 3 is the traction force/braking force distribution flowchart of embodiment 4 of the present invention

Fig. 4 is a schematic diagram of force exerted on rollers of the track adhesion coefficient detection device according to Embodiment 4 of the present invention.

Detailed ways

As shown in Figure 1, Embodiment 1 of the present invention is used to obtain tangential traction force. In Embodiment 1, a small steel wheel 1 (roller) is added on the first bogie frame of the head car, and the steel wheel 1 can run on the track. The steel wheels are arranged between two wheels on one side of two adjacent wheel pairs. The bearing outer side of the steel wheel is connected with the vertical support seat 2 (the first support seat) arranged on the bogie frame through the connecting rod 11 (vertical arrangement) and the air spring 3 successively.

A small-sized air spring 3 is assembled on the vertical support seat 2 (the first support seat) of the steel wheel, and the cylinder pressure can be adjusted as required, and a vertical pressure Fn is applied to the steel wheel, so that the steel wheel can run with the car. When the vehicle is stationary, when the pressure value of the air spring 3 is 0, due to the tension of the steel spring 4, the steel wheel 1 will not touch the track.

The rotation of the steel wheel 1 is independently driven by a micro motor 7 driving the transmission belt/shaft 8, and the traction output can be adjusted according to the needs, so that the creep speed of the steel wheel is slightly greater than the speed of the vehicle, enters the stable sliding stage, and is converted into the contact point of the steel wheel. The tangential traction force F1.

Embodiment 2 of the present invention is used to obtain tangential braking force. In Embodiment 2, a small-sized brake caliper 10 is assembled on the vertical support base 2 of the steel wheel 1, and the clamp 10 is driven by the air supply air cylinder 9, and the air cylinder 9 is assembled on the vertical support base 2, and can be adjusted as required. The clamping force of the steel wheel makes the creep linear velocity of the steel wheel slightly lower than the vehicle speed, enters the stable sliding stage, and converts the tangential braking force F2 at the contact point of the steel wheel.

The air spring (air spring) 3 lower support seat (second support seat) of the steel wheel 1 is equipped with a pressure sensor 5, which can accurately detect the vertical pressure Fn of the steel wheel in real time. The upper end of the air spring is connected to the first support seat, and the lower end is connected to the second support seat.

A range finder 6 is assembled on the lower support seat of the empty spring 3 of the steel wheel 1, which can accurately detect the distance between the top of the steel wheel and the center point of the steel wheel bearing in real time, that is, the radius r of the steel wheel.

In Embodiment 3 of the present invention, two small steel wheels 1 (rollers) can also be added on the bogie frame, and the two rollers are respectively arranged between two wheels on both sides of two adjacent wheel pairs. The corresponding structures of the remaining parts are the same as those in Embodiment 1/Embodiment 2, and will not be repeated here.

As shown in Figure 3, in Embodiment 4 of the present invention, the traction/braking force distribution process includes the following steps:

1) After the vehicle is activated and powered on, the devices in Embodiment 1 and Embodiment 2 perform self-inspection;

2) Determine whether the device is faulty, if so, restart the device of embodiment 1 and embodiment 2, and re-judge whether there is a fault, if it is judged that there is a fault in the self-inspection three times, then report the fault information; otherwise, wait for the vehicle to enter the main line operation ;

3) Determine whether the vehicle is running, if not, continue to wait for the vehicle to issue a permission command; otherwise, the air spring starts to inflate to the target pressure value;

4) Determine whether the motor/air cylinder is working normally, if not, report the fault of the motor/air cylinder; if so, the motor/air cylinder will give stepping traction/braking force;

5) Determine whether the creep line speed of the steel wheel reaches the threshold value, if not, return to step 4); if yes, convert the current wheel-rail adhesion coefficient, and enter step 6; at the same time, the motor/air cylinder locks the traction/braking force, and After a certain period of time, return to step 4);

6) Send the adhesion coefficient to the traction system and braking system through the vehicle network;

7) After the traction system receives the adhesion coefficient, it adjusts the current maximum traction force and electric braking force envelope, and judges whether to start idling protection; after the braking system receives the adhesion coefficient, it adjusts the current maximum Adjust the braking force envelope and judge whether to activate the coasting protection;

8) When the idling protection or coasting protection is started, the traction system sends the idling protection signal to the motor, and the braking system sends the coasting protection signal to the air cylinder, and the devices in Embodiment 1 and Embodiment 2 fine-tune the threshold value, and return to step 4);

Dispensing ends when dry run protection or coast protection is not activated;

9) Judging whether the vehicle exits the main line operation, if so, the air spring exhausts, the devices of embodiment 1 and embodiment 2 are on standby, and judges whether the vehicle is activated; otherwise, directly determines whether the vehicle is activated;

10) If the vehicle is not activated, then turn off the devices of Embodiment 1 and Embodiment 2; otherwise, return to step 9).

It should be noted that in the above process, the traction system and the control system are independently controlled.

As shown in Figure 4, in Embodiment 4 of the present invention, when the train is running, the motor 7 pulls the steel wheel 1, so that the creep linear velocity V of the steel wheel 1 is slightly greater than the vehicle speed v. When the creep linear velocity of the steel wheel reaches the threshold value, the adhesion coefficient μ between the wheel and rail is calculated according to the detected vertical pressure Fn and the tangential traction force F1 at the contact point of the steel wheel (μ=F1/Fn).

When the train is running, the brake caliper 10 brakes the steel wheel 1 so that the creep linear velocity V of the steel wheel 1 is slightly smaller than the vehicle speed v. When the creep linear velocity of the steel wheel reaches the threshold value, the adhesion coefficient μ between the wheel and rail is calculated according to the detected vertical pressure Fn and the tangential braking force F2 at the contact point of the steel wheel (μ=F2/Fn).

Through the vehicle network, the value of the adhesion coefficient μ is transmitted to the traction system in real time, and the maximum traction force F (F=vehicle weight*μ) that can be exerted during the current track operation is calculated, and the value of the traction force is used as the maximum envelope of the traction system response , to prevent the bogie wheelset from idling during traction.

Through the vehicle network, the value of the adhesion coefficient μ is transmitted to the braking system in real time, and the maximum braking force that can be exerted during the current track operation is calculated, and the braking force value is used as the maximum envelope of the braking system's usual braking response to prevent Bogie wheelset slipping during frequent braking.

Claims (11)

1. A wheel-rail system comprises a rail and a wheel pair moving on the rail; the wheel pair is fixedly connected with the bogie frame through a series of springs; the wheel set is characterized in that a roller running on the track is arranged between two wheels on at least one side of two adjacent wheel sets; the bearing at the center of the roller is connected with a first supporting seat arranged on the bogie frame; and the first supporting seat is provided with a driving device for driving the roller and/or a braking device for adjusting the rotating speed of the roller.

2. The wheel-track system of claim 1, wherein a roller running on a corresponding track is provided between two wheels on both sides of two adjacent wheel pairs.

3. The wheel track system of claim 1, wherein the bearing is connected to the first support base sequentially via a connecting rod and an air spring.

4. The wheel track system of claim 3, wherein the air spring is connected at an upper end to the first support base and at a lower end to the second support base; and a pressure sensor is arranged on the second supporting seat.

5. The wheel-track system of claim 4, wherein a distance meter is provided on the second support base.

6. The wheel and rail system of claim 1, wherein the brake device includes a brake caliper in contact with a roller, the brake caliper communicating with a reservoir disposed on the first support base.

7. The wheel track system of claim 1, wherein the roller is disposed on a first truck frame of the head car.

8. A method for realizing traction/braking force distribution of rail transit vehicles by using the wheel pair system as claimed in any one of claims 1 to 7, the method comprising: and calculating the maximum traction force and/or the maximum braking force according to the adhesion coefficient, and controlling the traction force and the braking force of the vehicle to enable the traction force of the vehicle to be smaller than the maximum traction force and the braking force of the vehicle to be smaller than the maximum braking force.

9. The method of claim 8, wherein calculating the maximum tractive effort and/or the maximum braking effort based on the adhesion coefficient comprises:

controlling the creep linear speed of the roller to be greater than the running speed of the vehicle, and converting the tangential traction force F1 at the contact point of the roller and the track; when the creep linear velocity of the roller reaches a set threshold value, calculating a first adhesion coefficient mu 1 between the roller and the track according to the vertical pressure Fn and the tangential traction force F1 applied by the air spring to the roller; and/or the presence of a gas in the gas,

adjusting the clamping force on the roller by using a brake clamp, so that the creeping linear speed of the roller is smaller than the running speed of the vehicle, and converting a tangential braking force F2 at the contact point of the roller and the rail; when the creep linear velocity of the roller reaches a set threshold value, calculating a second adhesion coefficient mu 2 between the roller and the track according to the vertical pressure Fn and the tangential braking force F2 exerted on the roller by the air spring;

and respectively calculating the maximum traction force and the maximum braking force which can be exerted by the vehicle when the vehicle runs on the current track according to the first adhesion coefficient mu 1 and the second adhesion coefficient mu 2.

10. The method of claim 9, wherein prior to controlling the roller creep linear velocity to be greater than the vehicle operating speed, further comprising:

1) When the air spring is inflated to a target value, the driving device/the braking device outputs traction force/braking force;

2) Judging whether the creep linear speed of the roller reaches a set threshold value, if so, locking the traction/braking force by a driving device/a braking device, and returning to the step 1 after a set time period); otherwise, returning to the step 1).

11. The method of claim 10, wherein controlling vehicle traction and braking forces such that vehicle traction is less than the maximum traction and vehicle braking force is less than the maximum braking force further comprises:

judging whether to start idle protection, if so, adjusting the threshold value, and returning to the step 1); and (4) judging whether to start sliding protection, if so, adjusting the threshold value, and returning to the step 1).

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