Assembly process, assembly platform and automated assembly method for pressure sensors

Abstract

This invention discloses an assembly process, assembly platform, and automated assembly method for a pressure sensor, comprising: step a, freezing an elastic antifreeze plug in a low-temperature environment until it shrinks to a size smaller than the diameter of the drainage hole of the pressure sensor, changing its properties from elastic to brittle, and forming a frost layer on its surface; step b, with the drainage hole opening upwards; step c, inserting the antifreeze plug into the drainage hole to allow it to sink into the hole; step d, using a pressure rod to further penetrate the antifreeze plug; step e, checking whether the depth of the antifreeze plug in the drainage hole meets the standard; if not, repeating steps d and e until it does; step f, waiting for the antifreeze plug to thaw and restore its original size and elasticity, allowing the antifreeze plug to be elastically squeezed and fixed to the inner wall of the drainage hole. This invention, by freezing the antifreeze plug, reducing its size, making it brittle, and forming a frost layer on its surface to reduce friction, reduces the difficulty of inserting the antifreeze plug deep into the drainage hole while eliminating the need to apply lubricant to the surface of the antifreeze plug.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel vehicle tail gas treatment, in particular to an assembly process, an assembly platform and an automatic assembly method for a pressure sensor for fuel vehicle tail gas. BACKGROUND

[0002] The existing urea pressure sensor is installed in the urea pump of the fuel vehicle to monitor the automobile tail gas. The position of the urea pressure sensor in contact with the urea pump is equipped with an anti-freezing plug, which blocks the crystallization of urea in the cavity of the sensor, affecting the sensing of urea pressure by the pressure sensor.

[0003] At present, the assembly of the anti-freezing plug is completed by the supplier of the urea pressure sensor. The installation process is as follows: the anti-freezing plug is pre-installed in the sensor hole by manual pressing at room temperature, and then pressed into the hole bottom by a pressing tool. This assembly method has the following problems:

[0004] 1. Low efficiency of manual pressing, inconsistent pressing depth;

[0005] 2. After installation, the anti-freezing plug rebounds, resulting in improper installation of the final product, and even the anti-freezing plug falls off during transportation.

[0006] The prior art discloses a method for assembling a sealing ring, which discloses a scheme of coating a lubricant on the surface of the sealing ring, and then assembling the sealing ring after freezing. However, the lubricant in the above scheme cannot be used on the anti-freezing plug, because the lubricant will affect the detection of the pressure sensor. Therefore, it is a technical problem to be solved to develop a process for quickly assembling the anti-freezing plug into the drainage hole of the pressure sensor through freezing. SUMMARY

[0007] To solve the above problems, the present application provides an assembly process for a pressure sensor, which can freeze the anti-freezing plug and assemble it into the drainage hole of the pressure sensor without lubricant. The specific scheme is as follows:

[0008] The assembly process of the pressure sensor includes the following steps:

[0009] Step a, place the anti-freezing plug made of elastic material in a low-temperature environment to freeze, until the anti-freezing plug is reduced to a size smaller than the hole diameter of the drainage hole of the pressure sensor, the anti-freezing plug changes from elastic to brittle, and an ice layer with a thickness of 3-5 mm is condensed on the surface;

[0010] Step b, fix the pressure sensor with the drainage hole opening upward;

[0011] Step c, take the frozen anti-freezing plug and put it into the drainage hole, reduce the friction between the anti-freezing plug and the drainage hole through the ice layer on the surface of the anti-freezing plug, so that the anti-freezing plug can quickly descend, and the anti-freezing plug is prevented from being stuck in the drainage hole;

[0012] Step d, further insert the anti-freezing plug into the drainage hole by inserting the pressing rod into the drainage hole;

[0013] Step e, detect whether the depth of the anti-freezing plug in the drainage hole meets the standard, and if not, repeat steps d and e until the standard is met;

[0014] Step f, wait for the anti-freezing plug to thaw and recover to the original size and elasticity, so that the anti-freezing plug is elastically pressed and fixed between the anti-freezing plug and the inner wall of the drainage hole.

[0015] Further, the anti-freezing plug expands to the original size after thawing in step f, and the size of the anti-freezing plug is greater than the diameter of the drainage hole.

[0016] Further, in step a, the glass transition temperature of the anti-freezing plug is Tg, the brittle temperature of the anti-freezing plug is Tb, and the freezing temperature t of the anti-freezing plug is Tg≤t<Tb.

[0017] Further, the t is -40℃.

[0018] Further, in step a, the freezing time of the anti-freezing plug is greater than 10 min.

[0019] Further, an assembly platform for a pressure sensor assembly process, comprising a material turntable arranged horizontally, a pressing device, a depth detection device, a first mechanical claw and a second mechanical claw are uniformly distributed in the circumferential direction of the material turntable;

[0020] The pressing device comprises a pressing rod for pressing the anti-freezing plug into the drainage hole, a driving unit for driving the vertical displacement of the pressing rod, and a tool for fixing the pressure sensor;

[0021] The assembly platform is provided with a feeding tray for placing the pressure sensor outside the first mechanical claw;

[0022] The assembly platform is provided with a freezing box outside the second mechanical claw, and the freezing box is connected with the assembly platform through a conveying belt;

[0023] The assembly platform is provided with an output tray for receiving the assembled pressure sensor outside the depth detection device.

[0024] Further, the depth detection device is a CCD detector.

[0025] Further, the depth detection device and the first mechanical claw are symmetrically arranged on the right side of the material turntable, and a material conveying rack is arranged on the right side of the assembly platform, and the feeding tray and the output tray are arranged on the material conveying rack;

[0026] The pressing device and the second mechanical claw are symmetrically arranged on the left side of the material turntable, and the freezing box and the conveying belt are located on the left side of the assembly platform.

[0027] An automatic assembly method of an assembly platform of an assembly process of a pressure sensor, comprising the following steps:

[0028] Step 1, the first mechanical claw grabs the pressure sensor from the feeding tray to the material turntable;

[0029] Step 2, the material turntable rotates counterclockwise to send the pressure sensor to the second mechanical claw position, the conveying belt conveys the frozen anti-freeze plug to the second mechanical claw position, and the second mechanical claw grabs the frozen anti-freeze plug into the drainage hole of the pressure sensor;

[0030] Step 3, the material turntable rotates counterclockwise to send the pressure sensor to the pressing device position, controls the pressure sensor to be fixed, drives the driving unit to drive the pressing rod to press down to make the pipe plug further into the drainage hole;

[0031] Step 4, the material turntable rotates counterclockwise to send the pressure sensor to the CCD detector position, detects whether the depth of the frozen plug in the drainage hole meets the standard, if not, the material sensor rotates clockwise to send the pressure sensor to the pressing device position, and then repeats the steps 3 and 4 until the depth of the frozen plug in the drainage hole meets the standard;

[0032] Step 5, the first mechanical claw grabs the completed assembled pressure sensor into the discharge tray.

[0033] Compared with the prior art, the advantages of the present application are as follows:

[0034] 1. The present application freezes the anti-freeze plug to reduce its size, make it brittle and form an ice layer on the surface to reduce friction, which reduces the difficulty of installing the anti-freeze plug into the deep drainage hole without the need to coat lubricant on the surface of the anti-freeze plug;

[0035] 2. The present application further inserts the anti-freeze plug into the drainage hole through the insertion rod to avoid the anti-freeze plug from being ejected from the drainage hole;

[0036] 3. The present application implements an automatic assembly process through the assembly platform, which has the advantages of ensuring consistent assembly quality and improving assembly efficiency;

[0037] 4. The present application sets the positions of the pressing device, the depth detection device, the first mechanical claw and the second mechanical claw in the assembly platform, so that the material turntable quickly completes the assembly and detection processes through counterclockwise rotation, further improving the assembly efficiency;

[0038] 5、The application utilizes the moisture in the air to naturally condense into ice layer when freezing the anti-freezing plug, contains less moisture, and the moisture naturally evaporates after thawing, without remaining in the drainage hole. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The flow chart of the assembly process of the application;

[0040] Figure 2 The structural diagram of the assembly platform of the application;

[0041] The application is described in detail below. Obviously, the described embodiments are part of the embodiments of the application, not all embodiments. DETAILED DESCRIPTION

[0042] The technical solutions of the application will be described clearly and completely. Obviously, the described embodiments are part of the embodiments of the application, not all embodiments.

[0043] Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0044] In the description of the application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "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 convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to has a particular orientation, is constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0045] In the description of the application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances. Embodiment 1

[0046] As shown in Figure 1 The assembly process of the pressure sensor includes the following steps:

[0047] Step a: Place the elastic antifreeze plug in a low-temperature environment to freeze until the antifreeze plug shrinks to a size smaller than the orifice of the pressure sensor, the antifreeze plug changes from elastic to brittle, and an ice layer with a thickness of 3-5 mm condenses on its surface, preferably 3 mm thick; the glass transition temperature of the antifreeze plug is Tg, the brittleness temperature of the antifreeze plug is Tb, and the freezing temperature t of the antifreeze plug is Tg≤t<Tb; preferably, t is -40℃. Specifically, the freezing time of the antifreeze plug is greater than 10 minutes.

[0048] Step b: Fix the pressure sensor with its drainage hole opening facing upwards;

[0049] Step c: Remove the frozen antifreeze plug and place it into the drainage hole. The frost layer on the surface of the antifreeze plug reduces the friction between it and the drainage hole, allowing the antifreeze plug to descend quickly and preventing it from getting stuck in the drainage hole.

[0050] Step d: Insert the pressure rod into the drainage hole to push the antifreeze plug further in;

[0051] Step e: Check if the depth of the antifreeze plug in the drainage hole meets the standard. If it does not meet the standard, repeat steps d and e until it does.

[0052] Step f: Wait for the antifreeze plug to thaw and return to its original size and elasticity, so that the antifreeze plug is elastically squeezed and fixed between itself and the inner wall of the drainage hole. After the antifreeze plug thaws, it expands and returns to its original size. The size of the antifreeze plug is larger than the diameter of the drainage hole. Example 2

[0053] like Figure 1 As shown, an assembly platform for a pressure sensor assembly process includes a horizontally arranged material turntable 2. Pressing devices 3, depth detection devices 4, a first mechanical claw 5, and a second mechanical claw 6 are evenly distributed around the circumference of the material turntable 2. The depth detection device 4 is a CCD detector.

[0054] The pressing device 3 includes a pressing rod for pressing the antifreeze plug into the drainage hole, a driving unit for driving the vertical displacement of the pressing rod, and a fixture for fixing the pressure sensor.

[0055] The assembly platform 1 is located on the outside of the first mechanical claw 5 and is equipped with a feeding tray 9 for placing pressure sensors;

[0056] A freezing box 7 is provided on the outside of the second mechanical claw 6 on the assembly platform 1, and a conveyor belt 8 is connected between the freezing box 7 and the assembly platform 1.

[0057] The assembly platform 1 is located outside the depth detection device 4 and is equipped with a discharge tray 10 for receiving the pressure sensor after assembly.

[0058] Furthermore, the depth detection device 4 and the first mechanical claw 5 are symmetrically arranged on the right side of the material turntable 2, and a material conveying frame 11 is provided on the right side of the assembly platform 1. The material conveying frame 11 is respectively arranged with the feeding tray 9 and the discharge tray 10.

[0059] The pressing device 3 and the second mechanical claw 6 are symmetrically arranged on the left side of the material turntable 2, and the freezing box 7 and the conveyor belt 8 are located on the left side of the assembly platform 1.

[0060] An automated assembly method for an assembly platform in the assembly process of a pressure sensor includes the following steps:

[0061] Step 1: The first mechanical gripper 5 picks up the gripping pressure sensor from the feeding tray 9 and transfers it to the material turntable 2;

[0062] Step 2: The material turntable 2 rotates counterclockwise to send the pressure sensor to the position of the second mechanical claw 6. The conveyor belt 8 transports the frozen antifreeze plug to the position of the second mechanical claw 6. The second mechanical claw 6 grabs the frozen antifreeze plug and puts it into the drain hole of the pressure sensor.

[0063] Step 3: The material turntable 2 rotates counterclockwise to send the pressure sensor to the pressing device 3. The control fixture fixes the pressure sensor, and the drive unit drives the pressure rod to press down so that the tube blockage is deep into the drainage hole.

[0064] Step 4: Rotate the material turntable 2 counterclockwise to send the pressure sensor to the CCD detector position to check whether the depth of the frozen plug in the drainage hole meets the standard. If it does not meet the standard, rotate the material sensor clockwise to send the pressure sensor to the pressing device 3 position and repeat steps 3 and 4 until the depth of the frozen plug in the drainage hole meets the standard.

[0065] Step 5: The first mechanical gripper 5 picks up the assembled pressure sensor and places it into the discharge tray 10.

[0066] The embodiments described above are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention 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 of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An assembly process for a pressure sensor, wherein the assembly platform includes a horizontally arranged material turntable (2), and pressing devices (3), depth detection devices (4), a first mechanical claw (5), and a second mechanical claw (6) are evenly distributed around the material turntable (2). The pressing device (3) includes a pressing rod for pressing the antifreeze plug into the drainage hole, a driving unit for driving the vertical displacement of the pressing rod, and a fixture for fixing the pressure sensor. The assembly platform (1) is located on the outside of the first mechanical claw (5) and is equipped with a feeding tray (9) for placing pressure sensors; The assembly platform (1) is located outside the second mechanical claw (6) and is equipped with a freezer (7). A conveyor belt (8) is connected between the freezer (7) and the assembly platform (1). The assembly platform (1) is located outside the depth detection device (4) and is equipped with a discharge tray (10) for receiving the pressure sensor after assembly. The depth detection device (4) and the first mechanical claw (5) are symmetrically arranged on the right side of the material turntable (2). A material conveying frame (11) is provided on the right side of the assembly platform (1). The feeding tray (9) and the discharge tray (10) are respectively arranged on the material conveying frame (11). The pressing device (3) and the second mechanical claw (6) are symmetrically arranged on the left side of the material turntable (2), and the freezing box (7) and the conveyor belt (8) are located on the left side of the assembly platform (1); Its features are, Includes the following steps: Step a: Place the elastic antifreeze plug in a low-temperature environment to freeze until the antifreeze plug shrinks to a size smaller than the diameter of the drainage hole of the pressure sensor, the antifreeze plug changes from elastic to brittle, and an ice layer with a thickness of 3 to 5 mm condenses on the surface. Step b: Fix the pressure sensor with its drainage hole opening facing upwards; Step c: Remove the frozen antifreeze plug and place it into the drainage hole. The frost layer on the surface of the antifreeze plug reduces the friction between it and the drainage hole, allowing the antifreeze plug to descend quickly and preventing it from getting stuck in the drainage hole. Step d: Insert the pressure rod into the drainage hole to push the antifreeze plug further in; Step e: Check if the depth of the antifreeze plug in the drainage hole meets the standard. If it does not meet the standard, repeat steps d and e until it does. Step f: Wait for the antifreeze plug to thaw and return to its original size and elasticity, so that the antifreeze plug is elastically squeezed and fixed between itself and the inner wall of the drainage hole.

2. The assembly process of the pressure sensor according to claim 1, characterized in that, In step f, the antifreeze plug expands back to its original size after thawing, and the size of the antifreeze plug is larger than the diameter of the drainage hole.

3. The assembly process of the pressure sensor according to claim 2, characterized in that, In step a, the glass transition temperature of the antifreeze plug is Tg, the brittleness temperature of the antifreeze plug is Tb, and the freezing temperature t of the antifreeze plug is Tg≤t<Tb.

4. The assembly process of the pressure sensor according to claim 3, characterized in that, The value of t is -40℃.

5. The assembly process of the pressure sensor according to claim 4, characterized in that, In step a, the freezing time of the antifreeze plug is greater than 10 minutes.

6. The assembly process of the pressure sensor according to claim 1, characterized in that, The depth detection device (4) is a CCD detector.

7. An automated assembly method for an assembly platform in the assembly process of a pressure sensor according to claim 1, characterized in that, Includes the following steps: Step 1: The first mechanical gripper (5) picks up the gripping pressure sensor from the feeding tray (9) and places it onto the material turntable (2); Step 2, the material turntable (2) rotates counterclockwise to send the pressure sensor to the position of the second mechanical claw (6), the conveyor belt (8) transports the frozen antifreeze plug to the position of the second mechanical claw (6), and the second mechanical claw (6) grabs the frozen antifreeze plug and puts it into the drain hole of the pressure sensor; Step 3: The material turntable (2) rotates counterclockwise to send the pressure sensor to the pressing device (3) position. The control fixture fixes the pressure sensor, and the drive unit drives the pressure rod to press down so that the tube blockage goes deep into the drainage hole. Step 4: Rotate the material turntable (2) counterclockwise to send the pressure sensor to the CCD detector position and check whether the depth of the frozen plug in the drainage hole meets the standard. If it does not meet the standard, rotate the material sensor clockwise to send the pressure sensor to the pressing device (3) position and repeat steps 3 and 4 until the depth of the frozen plug in the drainage hole meets the standard. Step 5: The first mechanical gripper (5) grabs the assembled pressure sensor and places it into the discharge tray (10).

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