A general electro-hydraulic and electro-pneumatic composite braking test device and method

Abstract

The present invention discloses a general electro-hydraulic and electro-pneumatic composite braking test device. When in use, first, the composite braking control system selects hydraulic or pneumatic braking and starts the loading motor. When the brake disc reaches the rotational speed and torque to be measured, the hydraulic or pneumatic pressure brakes the brake disc. The total required braking torque is calculated based on the braking situation and is synchronously transmitted to the test device control system. Subsequently, the motor braking torque is calculated according to the corresponding composite braking algorithm and is converted into an electric motor braking torque command and sent to the drive motor. At the same time, the corresponding torque command is sent to the loading motor. Then, the composite braking control system calculates the total required braking torque minus the drive motor braking torque to obtain the required hydraulic or pneumatic braking force. The composite braking control system gives the corresponding hydraulic or pneumatic braking pressure to the hydraulic or pneumatic brake disc, thereby realizing the test of electro-hydraulic and electro-pneumatic electric wheels with one test bench and improving the efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive engineering, and particularly to a general electro-hydraulic and electro-pneumatic composite braking test device and method. Background Technique

[0002] With the aggravation of the global energy crisis and environmental crisis, electric vehicles with green environmental protection functions have gradually become products favored by many consumers. Compared with traditional fuel vehicles, the braking energy recovery function generated by the electric motor braking of electric vehicles can recover and utilize a considerable part of the kinetic energy dissipated into the air, so the cruising range of electric vehicles can be effectively improved. Therefore, a composite braking system equipped with a braking energy recovery function has become a standard configuration for many electric vehicles. However, due to the addition of electric motor braking, the braking performance of the vehicle has changed greatly, and the test of the electric vehicle composite braking system has become the focus of current research. However, since the composite braking system involves multi-field energy conversion such as mechanical-electro-hydraulic / pneumatic, special test equipment is required to complete the composite braking test. Currently, dedicated composite braking test devices are designed and built for different vehicle models, lacking generality and interchangeability, which seriously affects the progress of electric vehicle composite braking technology.

[0003] However, the current composite braking test benches are professionally designed for specific structural forms, making it difficult to perform the functions of the general structural parts between test benches of different structural forms, as well as between electro-hydraulic and electric test benches, resulting in disadvantages such as low utilization efficiency and poor interchangeability of the test benches. Summary of the Invention

[0004] The purpose of the present invention is to provide a general electro-hydraulic and electro-pneumatic composite braking test device and method to overcome the disadvantages of low utilization efficiency and poor interchangeability of the existing composite braking test benches.

[0005] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a general-purpose electro-hydraulic and electro-pneumatic composite braking test device. When in use, first, the composite braking control system selects hydraulic or pneumatic braking, and starts the loading motor through the test device control system. When the brake disc reaches the measured rotational speed and torque, the composite braking control system brakes the hydraulic or pneumatic brake disc. The electronic control unit of the composite braking control system calculates the total required braking torque according to the braking situation, and synchronously transmits the calculated total required braking torque to the test device control system through the communication bus. Subsequently, the electronic control unit of the composite braking control system calculates the motor braking torque according to the corresponding composite braking algorithm and converts it into a motor braking torque command to send to the drive motor. At the same time, the test device control system sends the corresponding torque command to the loading motor. After that, the electronic control unit of the composite braking control system calculates the total required braking torque minus the drive motor braking torque to obtain the required hydraulic or pneumatic braking force, and then the composite braking control system gives the corresponding hydraulic braking pressure or pneumatic braking pressure to the hydraulic or pneumatic brake disc, thereby realizing the test of electro-hydraulic and electro-pneumatic electric wheels with one test bench and improving the efficiency.

[0006] Further, the composite braking control system includes a hydraulic brake valve, a pneumatic brake valve, and a hydraulic-pneumatic switching device. The hydraulic brake valve is connected to the hydraulic brake, the pneumatic brake valve is connected to the pneumatic brake, and both the hydraulic brake valve and the pneumatic brake valve are connected to the hydraulic-pneumatic switching device, which can achieve seamless switching between hydraulic and pneumatic tests.

[0007] Further, an environmental chamber with adjustable temperature is provided outside the hydraulic brake and the pneumatic brake, which can adjust the test temperature environment and obtain more accurate test results.

[0008] Further, the present invention also provides a general-purpose electro-hydraulic and electro-pneumatic composite braking test method, which can improve the efficiency of electro-hydraulic and electro-pneumatic braking tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of a general-purpose electro-hydraulic and electro-pneumatic composite braking test device of the present invention;

[0010] Figure 2 is a schematic diagram of a static braking test device of the present invention;

[0011] Figure 3 is a schematic diagram of a dynamic braking test device of the present invention;

[0012] Figure 4 is a schematic diagram of a dynamic braking test device after adding an environmental chamber to the dynamic braking test device of the present invention;

[0013] Figure 5 is a working flowchart of the composite braking test system of the present invention;

[0014] In the figure, 1 is a static braking test device, 2 is a dynamic braking test device, 3 is a composite braking control system, 4 is a test device control system, 5 is a braking load motor, 6 is a first infinitely variable transmission, 7 is a hydraulic brake, 8 is a pneumatic brake, 9 is an electromagnetic clutch, 10 is a rotational speed and torque meter, 11 is a second infinitely variable transmission, 12 is an environmental chamber, 13 is a coupling, and 14 is a driving motor. Specific embodiments

[0015] The present invention will be further described in detail below in conjunction with specific embodiments, which are explanations of the present invention rather than limitations.

[0016] As Figures 1-5 shown, the present invention provides a general-purpose electro-hydraulic and electro-pneumatic composite braking test device and method:

[0017] It includes a static braking test device 1, a composite braking control system 3, a dynamic braking test device 2, and a test device control system 4. The electro-hydraulic composite braking system can respectively perform electro-hydraulic composite braking dynamic tests and hydraulic brake 7 static tests, or perform electro-pneumatic composite braking dynamic tests and pneumatic brake 8 static tests.

[0018] Among them, the electro-hydraulic composite braking dynamic test and the electro-pneumatic composite braking dynamic test are carried out on the dynamic braking test device 2; the static test of the hydraulic brake 7 or the static test of the pneumatic brake 8 is arranged on the static braking test device 1 for the static test of hydraulic or pneumatic braking force when verifying the braking force distribution of the composite braking strategy. The static test system of the hydraulic brake 7 consists of three non-rotating hydraulic brake discs, an electro-hydraulic pump, a hydraulic brake pipeline, a hydraulic brake wheel cylinder, etc. The static test system of the pneumatic brake 8 consists of three non-rotating pneumatic brake discs, front and rear air storage tanks, an air compressor, a relay valve, a pneumatic brake pipeline, a pneumatic brake wheel cylinder, etc.

[0019] The dynamic braking test device 2 is composed of a braking load motor 5, a first continuously variable transmission 6, a transmission shaft, a second continuously variable transmission 11, a coupling 13, a hydraulic brake 7, a pneumatic brake 8, a rotational speed and torque meter 10, a drive motor 14 and its controller, etc. Among them, the braking load motor 5 is connected to the first continuously variable transmission 6, and by changing the transmission ratio, it simulates the changes in the rotational speeds of the brake and the drive motor 14 during the braking process of the vehicle at different braking speeds; although both the hydraulic brake 7 and the pneumatic brake 8 are driven to rotate simultaneously by the braking load motor 5, the working pressures in the brake pipelines between the two cannot be established simultaneously, that is, they cannot work simultaneously, so as to ensure that the system can separately simulate electro-hydraulic composite braking or electro-pneumatic composite braking; the drive motor 14 and its controller work in the electric braking state and are used to provide the braking torque during regenerative braking. The braking torque provided by them is measured by the rotational speed and torque meter 10. The coupling 13 is used to connect parts with different diameters so that each area can operate on the same axis. The rotational speed and torque meter 10 is used to measure data such as the torque, rotational speed, and power of the motor during braking.

[0020] The composite braking control system 3 of the present invention includes two sets of systems, namely a hydraulic braking system and a pneumatic braking system (including hydraulic and pneumatic connectors), and an electronic control unit; the hydraulic / pneumatic switching system is a switching system composed of a set of two-way switching valves. When an electro-hydraulic composite braking test is required, the switching switch is turned to the hydraulic position to achieve the cooperation between hydraulic braking and motor regenerative braking; similarly, when an electro-pneumatic composite braking test is required, the switching switch is turned to the pneumatic position to achieve the cooperation between pneumatic braking and motor regenerative braking.

[0021] The hardware of the test device control system 4 is composed of an industrial computer, an upper computer display, a communication interface circuit, a data acquisition and recording device, etc. The software of the test device control system 4 is composed of an implementation monitoring and control system 4 developed by Labview software, and can perform corresponding braking tests and operations by setting different braking rates, different road conditions, different working conditions, and different vehicle loads. The software system can also call and switch the corresponding electro-hydraulic composite braking and electro-pneumatic composite braking programs to meet the requirements of various braking tests.

[0022] As Figure 5As shown, an environmental chamber 12 is provided outside the hydraulic brake 7 and the pneumatic brake 8. The composite brake control system 3 transmits instructions to the hydraulic / pneumatic switching device, which selects and controls hydraulic braking or pneumatic braking according to the tested brake type, and transmits the corresponding hydraulic braking pressure or pneumatic braking pressure to the corresponding hydraulic brake 7 or pneumatic brake 8 through pipelines respectively, so as to realize the switching between hydraulic braking and pneumatic braking. Inside the environmental chamber 12, to measure the temperature change of the brake under different working conditions by the split braking test bench, the sensors to be arranged include the brake caliper temperature sensor and the non-contact brake disc temperature sensor. An electromagnetic clutch 9 is also provided between the pneumatic brake 8 and the second infinitely variable transmission 11. The electromagnetic clutch 9 is controlled by the test device control system 4 to prevent the harm caused by torque imbalance to the equipment by adjusting the coupling torque. In addition, when selecting static braking test, the composite brake control system 3 calculates the corresponding hydraulic or pneumatic braking instructions according to the static braking test control algorithm and sends the instructions to the corresponding hydraulic brake or pneumatic brake on the static braking test device.

[0023] The working principle and process of this test device are as follows: Taking electro-hydraulic composite braking as an example, when the brake pedal is depressed, the composite brake control system 3 calculates the total required braking torque according to the opening of the electronic brake pedal, and synchronously transmits the total required braking torque to the test device control system 4 through the communication bus. Subsequently, the composite brake control system 3 calculates the motor braking torque according to the corresponding composite braking algorithm and converts it into a motor braking torque command and sends it to the drive motor 14. At the same time, the composite brake control system 3 calculates the remaining part of the total required braking torque minus the braking torque of the drive motor 14. The obtained remaining braking torque is the required hydraulic braking torque, which is transmitted to the hydraulic master cylinder through the switching valve of the hydraulic / pneumatic conversion device, and then pushes the piston of the master cylinder forward. The pressure of the brake fluid in the master cylinder increases and enters the wheel cylinders of each wheel through the oil pipeline, pushing the pistons of the wheel cylinders to expand outward, realizing the transmission of the force of stepping on the brake to the wheel brakes and pushing the wheel brakes to implement braking; when the brake pedal is released, the master cylinder piston returns under the action of oil pressure and the return spring, and the wheel cylinder pistons and the wheel brakes return to release the braking of the wheels.

[0024] In summary, the present invention can simulate the braking characteristics of electro-hydraulic and electro-pneumatic composite braking systems, conduct electro-hydraulic composite braking system or electro-pneumatic composite braking tests, simulate the control instructions of the torque and speed required for composite braking under different loads and working conditions, meet the real-time requirements, and realize the braking performance test control under the working condition mode of the composite braking system.

[0025] Although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Under the inspiration of the specification, those of ordinary skill in the art can also make many forms without departing from the scope protected by the claims of the present invention, and all of these are within the scope of protection of the present invention.

Claims

1. A general-purpose electro-hydraulic and electro-pneumatic composite braking test device, characterized in that It includes a dynamic braking test device (2), a compound braking control system (3) and a test device control system (4). The dynamic braking test device (2) includes a braking load motor (5), a first stepless speed changer (6), a hydraulic brake (7), a coupling (13), a pneumatic brake (8), a second stepless speed changer (11), a rotational speed and torque meter (10) and a drive motor (14) which are connected in sequence. The dynamic test compound braking control system (3) is connected to the hydraulic brake (7), the pneumatic brake (8) and the drive motor (14). The test device control system (4) is connected to the compound braking control system (3) and the braking load motor (5). The compound braking control system (3) includes a compound braking controller, a hydraulic brake valve, a pneumatic brake valve and a hydraulic-pneumatic switching device. The hydraulic brake valve is connected to the hydraulic brake (7). The pneumatic brake valve is connected to the pneumatic brake (8). Both the hydraulic brake valve and the pneumatic brake valve are connected to the hydraulic-pneumatic switching device. The compound braking control system (3) further includes an electronic brake pedal which is connected to the hydraulic-pneumatic switching device.

2. The general electro-hydraulic and electro-pneumatic composite braking test device according to claim 1, characterized in that, An electromagnetic clutch (9) is further arranged between the pneumatic brake (8) and the second stepless speed changer (11). The electromagnetic clutch (9) is controlled by the test device control system (4).

3. A general electro-hydraulic and electro-pneumatic composite braking test device according to claim 1, characterized in that An environmental chamber (12) with temperature regulation is arranged outside the hydraulic brake (7) and the pneumatic brake (8).

4. A general electro-hydraulic and electro-pneumatic composite braking test device according to claim 3, characterized in that A brake caliper temperature sensor and a brake disc non-contact temperature sensor are arranged inside the environmental chamber (12).

5. A general electro-hydraulic and electro-pneumatic composite braking test device according to claim 1, characterized in that, A static braking test device (1) is arranged above the dynamic braking test device (2).

6. A general electro-hydraulic and electro-pneumatic composite braking test device according to claim 5, characterized in that, The static braking test device (1) includes a pneumatic static braking test device and a hydraulic static braking test device. The hydraulic static braking test device includes three non-rotating hydraulic brake discs and an external hydraulic braking device. The pneumatic static braking test device includes three non-rotating pneumatic brake discs and an external pneumatic braking device.

7. A general electro-hydraulic and electro-pneumatic composite braking test device according to claim 1, characterized in that, The software of the test device control system (4) is monitored through Labview software.

8. A general electro-hydraulic and electro-pneumatic composite braking test method, based on the device according to any one of claims 1-7, characterized in that, First, the composite braking control system (3) selects hydraulic or pneumatic braking. The test device control system (4) is used to start the braking load motor (5). When the hydraulic brake (7) or pneumatic brake (8) reaches the rotational speed and torque to be measured, the composite braking control system (3) brakes the hydraulic brake (7) or pneumatic brake (8). The composite braking control system (3) calculates the total required braking torque according to the braking situation and transmits the calculated total required braking torque to the test device control system (4) via the communication bus. Subsequently, the composite braking control system (3) calculates the motor braking torque and converts it into a motor braking torque command to be sent to the drive motor (14). At the same time, the test device control system (4) sends the corresponding torque command to the braking load motor (5). After that, the composite braking control system (3) calculates the total required braking torque minus the braking torque of the drive motor (14) to obtain the required hydraulic or pneumatic braking torque. Furthermore, the composite braking control system (3) applies the corresponding hydraulic braking pressure or pneumatic braking pressure to the hydraulic or pneumatic brake disc.

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