Test fixture for verifying performance of helicopter wheel brake pressure sensor

Abstract

The invention belongs to the technical field of tool design, and particularly relates to a test fixture for verifying the performance of a helicopter wheel brake pressure sensor. The test clamp comprises a mounting rack, a force application module, a force measurement module, a volume measurement assembly and a stroke detection module.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tooling design, and particularly relates to a test fixture for performance verification of a helicopter wheel brake pressure sensor. BACKGROUND

[0002] The helicopter wheel brake system is an important system for ensuring the safe take-off and landing of a helicopter. In the design and verification process of the related components of the helicopter brake system, a test fixture plays a crucial role. The traditional test fixture can usually only perform single-function tests. For example, the piston rod starting force test of the brake pressure sensor adopts the method of compressing the piston rod bearing by a spring scale, the axial operating force adopts the method of hanging weights, and the oil discharge volume requires multiple people to cooperate to collect and discharge the oil volume by a measuring cup, and the like. The traditional test fixture lacks the comprehensive evaluation capability of the overall performance of the brake system. In addition, the existing fixture has obvious deficiencies in simulating the dynamic response under actual working conditions, and the structure of multiple fixtures is complicated to operate, which increases the working strength of the test personnel. In order to improve this situation, there is an urgent need for an effective method to solve this problem. SUMMARY

[0003] The technical problem to be solved by the application is to provide a test fixture for performance verification of a helicopter wheel brake pressure sensor, and to improve the comprehensive evaluation capability of the overall performance of the brake system.

[0004] The technical scheme of the application is In a first aspect, a test fixture for performance verification of a helicopter wheel brake pressure sensor is provided, comprising: a mounting frame, a force applying module, a force measuring module, a volume measuring assembly, and a stroke detection module. The mounting frame comprises a force applying module support and a product fixing frame fixed on a bottom plate. The force applying module support is installed at the top end of the force applying module, and the force applying end of the force applying module is installed with the force measuring module. The product fixing frame is installed on the bottom plate below the force measuring module, and comprises a test piece limiting plate at the top end and a support arm. The test piece passes through the test piece limiting plate at the top end, and the top end is opposite to the force measuring module. The support arm is fixed with the middle part and the lower part of the test piece at the upper middle part and the lower part. The volume measuring assembly is installed on one side of the support arm, and is in communication with the oil outlet of the pressure sensor of the test piece. The stroke detection module is installed on the other side of the support arm, and receives the pressure transmitted through the force measuring module. The force measuring module is used to test the axial operating force, and the volume measuring assembly is used to record the oil discharge volume. The stroke detection module is used to measure the piston rod starting force in cooperation with the force measuring module.

[0005] Further, the force applying module comprises a gas cylinder, a screw rod, a spring washer, and a bolt. The gas cylinder is fixed on the force applying module support by the bolt, and the output shaft is fixed at the lower end of the screw rod. The part of the screw rod extending out of the force applying module support is sleeved with the spring washer.

[0006] Further, the force measuring module comprises a tension and pressure sensor, a screw, a rubber pad, an adjusting block, a knurled nut, a forked ear, a baffle, a shaft pin, a spring washer, and a thin nut. The tension and pressure sensor is connected with the part of the screw rod extension force measuring module support, the screw is reversely installed at the lower end surface of the tension and pressure sensor, the screw head is sleeved with the rubber pad, the rubber pad is in turn pressed against the adjusting block and the knurled nut, the inner thread of the knurled nut is matched with the thread of the rod end of the forked ear, the rod end penetrates through the test piece limiting plate, the double ear pieces of the forked ear are inserted into the upper end of the test piece, the baffle is arranged outside one ear piece, and the baffle, the ear piece and the upper end of the test piece are fixed by the shaft pin, the spring washer and the thin nut.

[0007] Further, the volume measuring assembly comprises a bolt, an upper head, a pipe sleeve, a glass tube, a lower head, a rubber pad, and an oil inlet pipe joint. The glass tube is arranged in the pipe sleeve, the upper end of the pipe sleeve is installed to the one side surface of the support arm through the upper head, and the lower end of the pipe sleeve is installed to the one side surface of the support arm through the lower head; the upper head is internally provided with a vent hole for communicating the glass tube with the outside, the lower head is internally provided with a flow channel, the oil inlet pipe joint is arranged at the inlet of the flow channel, the oil inlet pipe joint is communicated with the oil outlet of the pressure sensor, and the rubber pad is arranged at the communication area between the lower head and the lower end of the pipe sleeve.

[0008] Further, the stroke detection module comprises a disc head screw and a dial indicator fixed clamp. The dial indicator fixed clamp fixes the dial indicator to the other side surface of the support arm through the disc head screw.

[0009] Further, the test device further comprises a hose assembly, and the hose assembly is communicated with the oil outlet of the pressure sensor of the volume measuring assembly and the test piece.

[0010] In a second aspect, a test method for calibrating the performance of a helicopter wheel brake pressure sensor is provided, which comprises the following steps. The test device for calibrating the performance of a helicopter wheel brake pressure sensor is used to perform a piston rod starting force test, an oil displacement test, a minimum axial control force test, and a maximum axial control force test. Through the above tests, it is detected whether the related performance indexes are consistent with the design indexes, so that the calibration and verification of the piston rod starting force, the oil displacement, and the axial control force of the helicopter wheel brake pressure sensor are realized.

[0011] Further, the piston rod starting force test comprises the following steps. The knurled nut is adjusted, the adjusting block is padded, the knurled nut is manually rotated to cause the screw rod to slowly exert force, when the product valve just closes, the size of the force displayed by the tension and pressure sensor is observed, and the stroke of the product piston rod displayed by the dial indicator is observed. Further, the oil displacement test comprises the following steps. Slowly load the cylinder of the force module, pass the stroke through the baffle fixed on the fork ear and read the dial gauge, when the piston rod stroke is the predetermined product index stroke, measure the oil volume in the volume measurement assembly.

[0012] Further, the minimum axial operating force test includes: Close the pressure sensor oil outlet of the test piece, slowly load the cylinder of the force module, adjust the cylinder to the appropriate loading speed and force size, and then start the test, when the dial gauge indicates that the piston rod stroke is 2±1mm, and the pressure sensor oil outlet pressure is 0.9±0.1Mpa, observe the force size displayed by the tension and pressure sensor. Close the pressure sensor oil outlet of the test piece, slowly load the cylinder of the force module, adjust the cylinder to the appropriate loading speed and force size, and then start the test, and press the piston rod stroke to 5Mpa, and observe the force size displayed by the digital display of the tension and pressure sensor.

[0013] The application has the beneficial effects that a new comprehensive performance verification test fixture and test method for a helicopter wheel brake pressure sensor are provided, various test functions are integrated into one test fixture through modular design, integrated testing of piston rod power test, oil discharge test, minimum axial operating force test and maximum axial operating force test is realized, the device is simple in structure, convenient to operate, and can meet the requirements of verifying related indexes of a comprehensive performance verification test fixture for a helicopter wheel brake pressure sensor, and is beneficial to improving work efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a whole schematic view of the test fixture.

[0015] Figure 2 It is a side view of the test fixture.

[0016] Figure 3a It is a schematic view of the mounting frame.

[0017] Figure 3b It is a D-D sectional view of the mounting frame.

[0018] Figure 3c It is an E-E sectional view of the mounting frame.

[0019] Figure 4 It is a schematic view of the force module.

[0020] Figure 5 It is a schematic view of the force module.

[0021] Figure 6 It is a schematic view of the volume measurement assembly.

[0022] Figure 7 is a schematic view of a stroke detection module.

[0023] Figure 8 is a schematic view of a hose assembly. DETAILED DESCRIPTION

[0024] For the purpose of making the purposes, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more details below in combination with the drawings in the embodiments of the present application. In the drawings, the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation on the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor under the premise that the embodiments in the present application fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below in combination with the drawings.

[0025] In the description of the present application, it should be understood that the terms "center", "axial", "vertical", "upper", "lower", "upper end", "bottom end", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0026] Referring to Figures 1-3c The structure of the brake pressure sensor test fixture: composed of a mounting frame, a force applying module, a force measuring module, a volume measuring assembly, a stroke detection module, and a hose assembly, connected into one body by assembly welding and bolt connection.

[0027] Referring to Figures 1-8The mounting frame 1 comprises: a base 1-1 designed and manufactured, a force applying module support 1-2 designed and manufactured, a product fixing frame 1-3 designed and manufactured, a bolt 1-4 designed and manufactured, a nut 1-5 designed and manufactured, and a spring washer 1-6 designed and selected. The force applying module 2 comprises: a cylinder 2-1 designed and selected, a screw rod 2-2 designed and manufactured, a spring washer 2-3 designed and selected, and a bolt 2-4 designed and manufactured. The force measuring module 3 comprises: a tension and pressure sensor 3-1 designed and selected, a screw 3-2 designed and manufactured, a rubber pad 3-3 designed and manufactured, an adjusting block 3-4 designed and manufactured, a knurled nut 3-5 designed and manufactured, a fork lug 3-6 designed and manufactured, a baffle 3-7 designed and manufactured, a shaft pin 3-8 designed and manufactured, a spring washer 3-9 designed and manufactured, and a thin nut 3-10 designed and manufactured. The volume measuring assembly 4 comprises: a slotted steel inclined washer 4-1 designed and manufactured, a bolt 4-2 designed and manufactured, an upper table head 4-3 designed and manufactured, a pipe sleeve 4-4 designed and manufactured, a glass tube 4-5 designed and manufactured, a lower table head 4-6 designed and manufactured, a rubber pad 4-7 designed and manufactured, and an oil inlet pipe joint 4-8 designed and manufactured. The stroke detection module 5 comprises: a disc head screw 5-1 designed and selected, a dial indicator 5-2 designed and selected, and a dial indicator fixing clamp 5-3 designed and manufactured. The hose assembly 6 comprises: a hose 6-1 designed and selected, a stainless steel ball valve 6-2 designed and selected, a pressure gauge 6-3 designed and selected, and an oil outlet pipe joint 6-4 designed and manufactured.

[0028] The mounting frame 1, the force applying module 2, the force measuring module 3, the volume measuring assembly 4, the stroke detection module 5, and the hose assembly 6 are assembled by welding and bolting to form a comprehensive performance verification test fixture for a helicopter wheel brake pressure sensor. The product is clamped and fixed by the product fixing frame 1-3 of the mounting frame 1. The force applying module 2 is fixed on the force applying module support 1-2 of the mounting frame 1 by bolting and is connected and fixed with the force measuring module 3 by the screw rod 2-2 and the spring washer 2-3. The fork lug 3-6 of the force measuring module 3 is connected with the product by the shaft pin 3-8, the spring washer 3-9, and the thin nut 3-10. The oil outlet of the product is connected with the volume measuring assembly 4 by the hose assembly 6. After the stroke detection module 5 is installed and fixed on the mounting frame 1, the reading value of the dial indicator 5-2 is adjusted to zero. That is, the product is fixed in the state shown in the figure, and the external oil source or load is connected. Figure 1

[0029] ​Piston rod starting force test: Adjust the knurled nut, insert the adjustment block, and manually rotate the knurled nut to slowly apply force to the screw. When the product valve is just closed, observe the force (approximately 40N-60N) on the digital display of the tension and compression sensor 3-1 and the product piston rod travel (read from the dial indicator 5-2). (The piston rod starting force should also include the weight of the knurled nut 3-5, fork ear 3-6, baffle 3-7, shaft pin 3-8, spring washer 3-9, and thin nut 3-10, which can be determined by weighing).

[0030] Oil discharge test: Figure 1 As shown, the cylinder of the force module is slowly loaded, the stroke is transmitted through the baffle fixed on the fork ear and the dial indicator is read. When the piston rod stroke is 17 mm, the volume of oil in the volume measuring assembly is measured, which should be greater than or equal to 2.6 cubic centimeters.

[0031] Minimum axial operating force test: Close the stainless steel ball valve of the hose assembly, slowly load it with the cylinder of the force module, adjust the cylinder to the appropriate loading speed and force, and then start the test. When the piston rod stroke is 2±1mm (read from dial indicator 5-2), and the pressure at the product outlet is 0.9±0.1Mpa (read from pressure gauge 6-3), observe the force on the digital display of the tension and compression sensor 3-1 (approximately 220N-270N).

[0032] Maximum axial operating force test: Close the stainless steel ball valve of the hose assembly, slowly load with the cylinder of the force module, adjust the cylinder to the appropriate loading speed and force, and then start the test. When the piston rod is pressed down to the pressure at the product output port of 5Mpa, observe the force on the digital display of the tension and compression sensor (approximately 750N-950N). Through the above steps, it is tested whether the relevant performance indicators are consistent with the design indicators, and the core performance parameters of the helicopter wheel brake pressure sensor, such as the piston rod starting force, oil displacement, and axial control force, are calibrated and verified.

[0033] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0034] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A test fixture for performance verification of helicopter wheel brake pressure sensors, characterized in that: include: Mounting frame (1), force application module (2), force measurement module (3), volume measurement assembly (4), stroke detection module (5); The mounting frame (1) includes a force module bracket fixed on the base plate and a product fixing frame; the force module (2) is installed on the top of the force module bracket, the force-applying end of the force module (2) is installed with a force-measuring module (3), and the product fixing frame is installed on the base plate below the force-measuring module (3), the product fixing frame includes a test piece limit plate and a support arm at the top, the upper end of the test piece passes through the test piece limit, the top is facing the force-measuring module (3), and the middle and lower parts of the support arm fix the middle and lower parts of the test piece; a volume measurement component (4) is installed on one side of the support arm, and the volume measurement component (4) is connected to the oil outlet of the pressure sensor of the test piece; a stroke detection module (5) is installed on the other side of the support arm to receive the pressure transmitted by the force-measuring module (3); the force-measuring module (3) is used to test the axial operating force, and the volume measurement component (4) is used to record the oil discharge volume; the stroke detection module (5) is used to cooperate with the force-measuring module to measure the piston rod starting force.

2. The clamp according to claim 1, characterized in that The force application module (2) includes a cylinder (2-1), a screw (2-2), a spring washer (2-3), and a bolt (2-4); The cylinder (2-1) is fixed to the force module bracket by means of bolts (2-4); the lower end of the output shaft is fixedly connected to a screw rod; the portion of the screw rod extending out of the force module bracket is covered with a spring washer (2-3).

3. The clamp according to claim 2, characterized in that The force measuring module (3) includes a tension and compression sensor (3-1), a screw (3-2), a rubber pad (3-3), an adjustment block (3-4), a knurled nut (3-5), a fork ear (3-6), a baffle (3-7), a shaft pin (3-8), a spring washer (3-9), and a thin nut (3-10); The tension and compression sensor (3-1) is connected to the part of the screw rod extending out of the force module bracket, the screw (3-2) is reversely installed on the lower end surface of the tension and compression sensor (3-1), the rubber pad (3-3) is covered on the screw head, and the rubber pad (3-3) presses the adjustment block (3-4) and the knurled nut (3-5) in sequence; the internal thread of the knurled nut (3-5) is matched with the rod end thread of the fork ear (3-6), the rod end passes through the test piece limit plate, the double ear pieces of the fork ear (3-6) are inserted into the upper end of the test piece, and a baffle (3-7) is arranged outside one ear piece, and the baffle (3-7), the ear piece and the upper end of the test piece are fastened by a shaft pin (3-8), a spring washer (3-9) and a thin nut (3-10).

4. The clamp according to claim 2, characterized in that The volume measurement assembly (4) includes: a bolt (4-2), an upper gauge head (4-3), a pipe sleeve (4-4), a glass tube (4-5), a lower gauge head (4-6), a rubber pad (4-7), and an oil inlet pipe joint (4-8); The glass tube (4-5) is installed in the tube sleeve (4-4); the upper end of the tube sleeve (4-4) is installed on the side of the support arm through the upper head (4-3), and the lower end is installed on the side of the support arm through the lower head (4-6); a vent hole connecting the glass tube (4-5) and the outside is provided in the upper head (4-3), a flow channel is provided in the lower head (4-6), an oil inlet pipe joint (4-8) is provided at the inlet of the flow channel, and the oil inlet pipe joint (4-8) is connected to the oil outlet of the pressure sensor; a rubber pad (4-7) is placed in the connecting area between the lower head (4-6) and the lower end of the tube sleeve (4-4).

5. The clamp according to claim 2, characterized in that The stroke detection module (5) includes: a pan head screw (5-1), a dial indicator (5-2), and a dial indicator fixing clamp (5-3); The dial indicator fixing clamp (5-3) fixes the dial indicator (5-2) to the other side of the support arm through the pan head screw (5-1).

6. The clamp according to claim 1, wherein: It also includes a hose assembly (6); the hose assembly (6) connects the volume measurement assembly (4) and the oil outlet of the pressure sensor of the test piece.

7. A test method for verifying the performance of a helicopter wheel brake pressure sensor, characterized in that: include: The test device for performance calibration of a helicopter wheel brake pressure sensor according to claim 1 is used to perform a piston rod starting force test, an oil displacement test, a minimum axial control force test, and a maximum axial control force test; Through the above tests, it is detected whether the relevant performance indicators are consistent with the design indicators, and the core performance parameters of the helicopter wheel brake pressure sensor, such as the piston rod starting force, oil displacement, and axial control force, are calibrated and verified.

8. The method according to claim 7, characterized in that Piston rod initial force test, including: Adjust the knurled nut (3-5), insert the adjustment block (3-4), and manually rotate the knurled nut (3-5) to cause the screw (3-6) to slowly apply force. When the product valve is just closed, observe the force displayed by the tension and compression sensor (3-1) and the product piston rod stroke displayed by the dial indicator (5-2).

9. The method according to claim 7, characterized in that Oil discharge test, including: The cylinder (2-1) of the force module (2) is slowly loaded, and the stroke is transmitted through the baffle (3-7) fixed on the fork ear (3-6) and read by the dial indicator (5-2). When the piston rod stroke reaches the predetermined product index stroke, the oil volume in the volume measurement component (4) is measured.

10. The method according to claim 7, characterized in that Minimum axial operating force test, including: Close the oil outlet of the pressure sensor of the test piece, slowly load the cylinder (2-1) of the force module (2), adjust the cylinder (2-1) to the appropriate loading speed and force, and then start the test. When the reading of the dial indicator (5-2) indicates that the piston rod stroke is 2±1mm, and the pressure at the oil outlet of the pressure sensor is 0.9±0.1Mpa, observe the force displayed by the tension and compression sensor (3-1); Close the oil outlet of the pressure sensor of the test piece, slowly load it with the cylinder (2-1) of the force module (2), adjust the cylinder (2-1) to the appropriate loading speed and force, and start the test. Press the piston rod until the pressure at the oil outlet of the pressure sensor reaches 5 MPa, and observe the force on the digital display of the tension and compression sensor (3-1).

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