Bridge clamp with adjustable clamping force

Abstract

The utility model relates to a bridge clamp with adjustable clamping force, which comprises two sets of clamp bodies, each set of clamp body comprises a fixed clamp and a movable clamp, the two movable clamps are respectively arranged at the end part of a piston rod of an air cylinder, two air inlets of each air cylinder are respectively connected with two air outlets of an electromagnetic valve through air pipes; air inlets of the two electromagnetic valves are connected to two ports of a three-way pipe respectively, a third port of the three-way pipe is connected with an air outlet of an electric proportional valve, an air inlet of the electric proportional valve is connected with an air source, the electric proportional valve and the electromagnetic valves are both electrically connected with an output interface of a PLC module, a touch screen is electrically connected with an input interface of the PLC module, and the touch screen is electrically connected with an output interface of the PLC module. And a power interface of the PLC module is connected with an external alternating current power supply through a 24V switching power supply. The PLC module is used for controlling the air outlet amount and air pressure of the electric proportional valve, so that the air pressure entering the air cylinder is adjusted, and then the clamping force of the clamp is adjusted.

Description

Technical Field

[0001] This utility model relates to the field of cable testing technology, and in particular to a bridge clamp with adjustable clamping force. Background Technology

[0002] The DC resistance test of conductors at 20℃ is a key project in the quality risk management of wires and cables. Currently, we mostly use hand-cranked bridge clamps to clamp and fix the conductor sample at 20℃. Due to the wide variety of cable conductor types and specifications, and the differences in their softness and hardness, coupled with the differences in clamping force between people, measurement errors are easily introduced. To avoid or reduce this measurement error, there is an urgent need for a bridge clamp that can easily adjust the clamping force, so as to achieve consistent clamping force for conductors of the same model and specification across different batches, and automatic orientation selection of clamping force for conductors of different models and structures. Utility Model Content

[0003] To address the shortcomings of existing technologies, this utility model discloses an adjustable clamping force bridge clamp, which can more conveniently adjust the clamping force to achieve consistent clamping force for conductors of the same model and specification across different batches, as well as automatic orientation selection of clamping force for conductors of different models and structures. This solves the existing technical problems of difficulty in controlling the clamping force of conductors and large measurement errors when using hand-cranked clamps.

[0004] This utility model is achieved through the following technical solution:

[0005] An adjustable clamping force bridge clamp includes two clamping bodies. Each clamping body includes a fixed clamp and a movable clamp. The two movable clamps are respectively located at the piston rod end of a cylinder. The two air inlets of each cylinder are respectively connected to the two air outlets of a solenoid valve through air pipes. The air inlets of the two solenoid valves are respectively connected to the two ports of a three-way pipe. The third port of the three-way pipe is connected to the air outlet of an electro-proportional valve. The air inlet of the electro-proportional valve is connected to an air source. The electro-proportional valve and the solenoid valve are both electrically connected to the output interface of a PLC module. A touch screen is electrically connected to the input interface of the PLC module. The power interface of the PLC module is connected to an external AC power source through a 24V switching power supply.

[0006] In a further optimized manner, the two digital output interfaces of the PLC module are electrically connected to the control terminals of the two solenoid valves via a 24V relay.

[0007] Furthermore, the analog output interface of the PLC module is electrically connected to the control terminal of the electro-proportional valve.

[0008] Further optimized, a pressure sensor is provided on the side of each movable clamp that contacts the conductor to be clamped, and the pressure sensor is electrically connected to the input interface of the PLC module.

[0009] Further optimized, the external AC power supply adopts 220V AC power.

[0010] The beneficial effects of this utility model are as follows: This utility model controls the output air volume and air pressure of the electric proportional valve through the PLC module, thereby adjusting the air pressure entering the cylinder, and thus realizing the adjustment of the clamping force of the fixture. Attached Figure Description

[0011] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or components are generally identified by similar reference numerals. In the drawings, the elements or components are not necessarily drawn to scale.

[0012] Figure 1 This is a schematic diagram of the air circuit of the bridge clamp of this utility model;

[0013] Figure 2 This is a circuit block diagram of the bridge clamp of this utility model;

[0014] In the diagram, 1 is the fixed clamp, 2 is the movable clamp, 3 is the cylinder, 4 is the solenoid valve, 5 is the electro-proportional valve, 6 is the PLC module, 7 is the touch screen, and 8 is the pressure sensor. Detailed Implementation

[0015] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0016] like Figure 1-2 As shown, an adjustable clamping force bridge clamp includes two sets of clamping bodies. Each set of clamping bodies includes a fixed clamp 1 and a movable clamp 2. The two movable clamps 2 are respectively located at the piston rod end of a cylinder 3. The two air inlets of each cylinder 3 are respectively connected to the two air outlets of a solenoid valve 4 through air pipes. The air inlets of the two solenoid valves 4 are respectively connected to the two ports of a three-way pipe. The third port of the three-way pipe is connected to the air outlet of an electro-proportional valve 5. The air inlet of the electro-proportional valve 5 is connected to an air source. The electro-proportional valve 5 and the solenoid valve 4 are both electrically connected to the output interface of a PLC module 6. A touch screen 7 is electrically connected to the input interface of the PLC module 6. The power interface of the PLC module 6 is connected to an external AC power source through a 24V switching power supply.

[0017] In some embodiments, the two digital output interfaces of the PLC module 6 are electrically connected to the control terminals of the two solenoid valves 4 via a 24V relay.

[0018] In some embodiments, the analog output interface of the PLC module 6 is electrically connected to the control terminal of the electro-proportional valve 5.

[0019] In some embodiments, a pressure sensor 8 is provided on the side of each movable clamp 2 that contacts the conductor to be clamped. The pressure sensor 8 is electrically connected to the input interface of the PLC module 6. The pressure sensor 8 can return the actual clamping force of the clamp to the PLC module 6, so that the PLC module 6 can dynamically fine-tune the air output and air pressure of the electro-proportional valve 5 according to the expected clamping force and the actual clamping force.

[0020] In some embodiments, the external AC power source is 220V AC.

[0021] After powering on, the conductor to be tested is placed between the movable clamp 2 and the fixed clamp 1 of the two clamps. According to the model and specifications of the conductor, the operator clicks the corresponding button or data on the touch screen 7, or inputs the corresponding data, and sends the air pressure adjustment command to the PLC module 6. According to the input air pressure adjustment command, the PLC module 6 outputs the corresponding voltage signal to the electro-proportional valve 5 through the analog output interface to adjust the air volume and air pressure of the outlet of the electro-proportional valve 5. The electro-proportional valve 5 outputs a certain air pressure and enters the air inlet of the two solenoid valves 4 respectively.

[0022] Then, by clicking the front clamping button and the rear clamping button on the touch screen 7, the PLC module 6 outputs DC24V voltage to the 24V relay, thereby controlling the solenoid valve 4 to perform action one, allowing gas to enter the cylinder 3 from one air inlet, causing the piston rod of the cylinder 3 to extend, completing the clamping of the conductor by the fixture, and outputting the expected clamping force. After the test is completed, by clicking the front release button and the rear release button on the touch screen 7, the PLC module 6 controls the solenoid valve 4 to perform action two, allowing gas to enter the cylinder 3 from the other air inlet, causing the piston rod to retract, removing the conductor under test, recording the data, and completing the test.

[0023] Through the above-mentioned air path design and circuit design, this utility model enables the PLC module 6 to control the output air volume and air pressure of the electric proportional valve 4, thereby adjusting the air pressure entering the cylinder 3 and thus realizing the adjustment of the clamping force of the fixture.

[0024] For conductors of different specifications and models, how much analog voltage output to the electro-proportional valve 4 is needed to obtain the required clamping force? One possible implementation is to pre-record this in a database. When the operator inputs or selects the conductor model and specifications via a touchscreen, the PLC module can obtain the required clamping force and convert it into the required analog voltage output, which is then sent to the electro-proportional valve. This controls the valve's airflow and pressure, adjusting the clamping force to achieve the desired clamping strength. The above software logic is a relatively conventional existing design and is not an innovation of this invention.

[0025] The above embodiments are merely illustrative of the technical solutions of this utility model and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model. For those skilled in the art, any alternative improvements or modifications made to the embodiments of this utility model fall within the protection scope of this utility model. Any aspects of this utility model not described in detail are well-known technologies to those skilled in the art.

Claims

1. A bridge clamp with adjustable clamping force, characterized in that: The device includes two clamping bodies, each consisting of a fixed clamp and a movable clamp. The two movable clamps are respectively located at the piston rod end of a cylinder. The two air inlets of each cylinder are connected to the two air outlets of a solenoid valve via air pipes. The air inlets of the two solenoid valves are respectively connected to the two ends of a three-way pipe. The third end of the three-way pipe is connected to the air outlet of an electro-proportional valve. The air inlet of the electro-proportional valve is connected to an air source. Both the electro-proportional valve and the solenoid valve are electrically connected to the output interface of a PLC module. A touch screen is electrically connected to the input interface of the PLC module. The power interface of the PLC module is connected to an external AC power source via a 24V switching power supply.

2. The adjustable clamping force bridge clamp according to claim 1, characterized in that: The two digital output interfaces of the PLC module are electrically connected to the control terminals of the two solenoid valves via a 24V relay.

3. The adjustable clamping force bridge clamp according to claim 1, characterized in that: The analog output interface of the PLC module is electrically connected to the control terminal of the electro-proportional valve.

4. The adjustable clamping force bridge clamp according to claim 1, characterized in that: A pressure sensor is provided on the side of each movable clamp that contacts the conductor to be clamped, and the pressure sensor is electrically connected to the input interface of the PLC module.

5. The adjustable clamping force bridge clamp according to claim 1, characterized in that: The external AC power supply is 220V AC.

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