CN113945205B - Assembly method of inertial measurement unit and assembly tool of inertial measurement unit - Google Patents

Abstract

The invention relates to the technical field of inertial navigation, in particular to an assembly method of an inertial measurement unit, which comprises the following steps: step one, sequentially and horizontally placing a bottom shell and a circuit board into a heating groove on an assembly tool; step two, assembling the bottom shell and the circuit board; step three, heating the part coated with the epoxy resin after assembly; compared with the existing assembly mode, the bottom shell and the circuit board can be directly clamped and heated in the assembly tool without moving to the heating box, so that the assembly steps are simplified, the phenomenon that epoxy resin flows on the bottom shell and the circuit board due to movement is avoided, in the process, the quick clamp in the assembly tool continuously presses down the circuit board, and the situation that the bottom shell and the circuit board are displaced can be avoided; a spring telescopic compression column is designed between the quick clamp and the protection assembly, the downward pressure of the quick clamp is buffered, and the condition that local stress of a circuit board exceeds limit due to overlarge downward pressure of the quick clamp is avoided.

Description

Assembly method of inertial measurement unit and assembly tool of inertial measurement unit

Technical Field

The invention relates to the technical field of inertial navigation, and in particular to an assembly method of an inertial measurement unit and an assembly tool of the inertial measurement unit.

Background Art

In the fields of unmanned driving and motion measurement, there is a rigid demand for the use of inertial measurement units. MEMS gyroscopes and accelerometers are designed using micro-electromechanical (MEMS) technology and have the characteristics of light weight, high precision, and no interference. The market demand for such MEMS inertial measurement units is large, which places high demands on the production efficiency of the equipment.

The inertial measurement unit mainly consists of a base case and a circuit board. Since the circuit board is relatively sensitive to stress, temperature and other conditions during the assembly process, in order to ensure the consistency of temperature changes inside the equipment and avoid damage to the device welding position under high overload conditions, epoxy resin is usually applied between the base case and the circuit board to improve the impact resistance of the equipment.

In the prior art, the bottom shell is first placed on a support table, epoxy resin is applied on the upper surface of the bottom shell, and then the circuit board is covered on the upper surface of the bottom shell. Then, a clamping device (such as a quick clamp, etc.) is used to clamp the bottom shell and the circuit board to bond the bottom shell and the circuit board. Then, the bottom shell and the circuit board are moved from the assembly tool to a heating box, and the portion coated with epoxy resin is heated to solidify the epoxy resin. However, such an assembly method can easily cause uncured epoxy resin to flow on the bottom shell and the circuit board, thereby reducing the impact resistance of the equipment and making it easy to be damaged in actual use. In addition, since there is no downward pressure from the clamping device during the movement and the epoxy resin has not yet solidified, it is very easy for the bottom shell and the circuit board to be misaligned, resulting in a high defective rate of the equipment.

Summary of the invention

In view of this, the problem to be solved by the present invention is to provide an assembly method of an inertial measurement unit and an assembly tool of an inertial measurement unit.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

The assembly method of the inertial measurement unit comprises the following steps:

Step 1: Place the bottom case and circuit board horizontally into the heating tank on the assembly tool.

Step 2: Assemble the bottom case and circuit board

Step three, heating the parts coated with epoxy resin after assembly.

The step 1 is: covering the circuit board with a protective component; and applying epoxy resin between the bottom shell and the circuit board.

The second step is: the quick clamp in the assembly tool presses down the protective component to make the bottom shell, epoxy resin and circuit board in close contact.

The step three is: the heating tank on the assembly tool is heated up, and the quick clamp in the assembly tool continuously presses down the circuit board until the epoxy resin is cured.

Assembly tools for inertial measurement units, including protective components and heating components;

The heating assembly comprises a supporting platform, on which a plurality of heating slots are arranged.

A limiting portion adapted to the contour of the inertial measurement unit is also configured in the heating groove.

The inner bottom surface of the heating tank is paved with an electric heating plate as a heat source, and the electric heating plate is electrically connected to a thermocouple sensor for temperature control.

The protection component includes an L-shaped suspension and a pin protection sleeve, wherein the pin protection sleeve is installed on the inner surface of the suspension and faces the heating tank.

The protection component also includes a limiting column and a pressure block. The pressure block is arranged at the bottom of the suspension and is used to offset the part of the circuit board where no circuit is designed; the limiting columns are equidistantly distributed on both sides of the pin protection sleeve and are used to penetrate the circular sleeve on the bottom shell.

The advantages and positive effects of the present invention are:

(1) The present invention is provided with a heating tank on the support table. After the bottom shell and the circuit board are pressed in the heating tank, the epoxy resin between the bottom shell and the circuit board can be directly heated. Compared with the existing assembly method, the bottom shell and the circuit board do not need to be moved to the heating box, and can be directly clamped and heated in the assembly tool, which simplifies the assembly steps and avoids the epoxy resin flowing on the bottom shell and the circuit board due to movement. In addition, during this process, the quick clamp in the assembly tool continuously presses down the circuit board to avoid displacement of the bottom shell and the circuit board.

(2) The present invention is designed with a protective component. When the quick clamp is pressed down, the pressure block on the protective component abuts against the portion of the circuit board that is not designed with a circuit, so that the bottom shell and the circuit board are pressed tightly. The pin protection cover on the protective component is put on the pins of the circuit board to prevent the pins of the circuit board from bending. It can not only achieve the compression of the bottom shell and the circuit board, but also prevent the pins of the circuit board from being pressed and bent.

(3) The present invention is designed with a spring-loaded retractable pressure column between the quick clamp and the protective component to buffer the downward pressure of the quick clamp, thereby avoiding the situation where the downward pressure of the quick clamp is too large, resulting in excessive local stress on the circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

In the attached picture:

FIG1 is a schematic diagram of a bottom shell;

FIG2 is a schematic diagram of a circuit board;

FIG3 is a block diagram of an assembly tool for an inertial measurement unit;

FIG4 is a schematic diagram of a protection assembly;

FIG5 is a schematic diagram of a protection component and a heating component;

In the figure: bottom shell 1, round sleeve 11, support platform 2, heating tank 21, electric heating plate 22, thermocouple sensor 23, limit part 24, circuit board 3, pin 31, quick clamp 4, pressure rod 41, suspension 51, pin protection sleeve 52, pressure block 53, limit column 54, mounting frame 6, lifting plate 61, spring telescopic pressure column 62.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and/or" used herein includes any and all combinations of one or more of the related listed items.

The assembly method of the inertial measurement unit comprises the following steps:

Step 1: Place the bottom shell 1 and the circuit board 3 horizontally into the heating tank 21 on the assembly tool in sequence;

Specifically, the bottom shell 1 is first placed in the heating tank 21, and then epoxy resin is applied to the upper surface of the bottom shell 1, and the circuit board 3 is covered on the upper surface of the bottom shell 1, and then the protective component is covered on the circuit board 3;

The protection component includes a pressing block 53 and a pin protection sleeve 52. The pin protection sleeve 52 is provided with a plurality of protection cavities corresponding to the pins 31 of the circuit board 3. The pin protection sleeve 52 is sleeved on the pins 31 to prevent the pins 31 from bending during the pressing process. The pressing block 53 is used to abut against the part of the circuit board 3 where no circuit is designed, so as to realize the pressing of the bottom shell 1 and the circuit board 3.

The horizontal placement design can avoid the epoxy resin flowing caused by the tilt of the bottom shell 1 and the circuit board 2 to the greatest extent, and can also directly apply pressure in the vertical direction of the circuit board 3 to press the bottom shell 1 and the circuit board 3 tightly, and facilitate the pin protection cover 52 to dock with the pin 31 on the circuit board 3.

Step 2: assemble the bottom shell 1 and the circuit board 3;

Specifically, the quick clamp 4 on the assembly tool is started, and the quick clamp 4 presses down the protective component, which presses the bottom shell 1 and the circuit board 3 in the heating tank 21 to make the bottom shell 1, epoxy resin and the circuit board 3 in close contact, avoiding gaps between the bottom shell 1, epoxy resin and the circuit board 3, resulting in loose bonding between the bottom shell 1 and the circuit board 3.

Step 3, heating the portion coated with epoxy resin after assembly;

Specifically, the heating source in the heating tank 21 is started to heat the epoxy resin between the bottom shell 1 and the circuit board 3, and the quick clamp 4 in the assembly tool continues to press down the circuit board 3 to prevent the epoxy resin from expanding after being heated, thereby preventing bubbles from existing between the bottom shell 1, the epoxy resin, and the circuit board 3, and making the bottom shell 1 and the circuit board 3 not firmly bonded; the quick clamp 4 stops pressing down the circuit board 3 until the epoxy resin is cured, and then the assembled bottom shell 1 and circuit board 3 are taken out of the heating tank 21, and the above steps are repeated.

Compared with the existing assembly method, the bottom shell 1 and the circuit board 3 do not need to be moved to the heating box, but can be directly clamped and heated in the heating slot 21 of the assembly tool, which simplifies the assembly steps and avoids the epoxy resin flowing on the bottom shell 1 and the circuit board 3 or the displacement of the bottom shell 1 and the circuit board 3 due to movement.

Assembly tools for inertial measurement units, including protective components and heating components;

Specifically, the heating assembly includes a support platform 2, on which a plurality of heating grooves 21 are arranged, and the inner bottom surface of the heating grooves 21 is provided with an electric heating plate 22 as a heat source, and the electric heating plate 22 is electrically connected to a thermocouple sensor 23 for temperature control, so as to ensure the temperature stability of the electric heating plate 22 during heating;

Specifically, a limiting portion 24 adapted to the contour of the inertial measurement unit is also configured in the heating groove 21 , so as to limit the bottom shell 1 and the circuit board 3 .

Specifically, the protection component includes an L-shaped suspension 51 and a pin protection sleeve 52. The pin protection sleeve 52 is installed on the inner surface of the suspension 51 and faces the heating slot 21. The pin protection sleeve 52 is provided with a plurality of protection cavities corresponding to the pins 31 of the circuit board 3. The pin protection sleeve 52 is used to be sleeved on the pins 31 to prevent the pins 31 from bending during the pressing process.

Specifically, the protective component also includes a pressing block 53, which is arranged at the bottom of the suspension 51 and is used to abut against the portion of the circuit board 3 where no circuit is designed, so as to press the bottom shell 1 and the circuit board 3; in this embodiment, the pressing block 53 is provided with three small pressing blocks and one large pressing block, and the pressing blocks 53 are evenly arranged on the bottom surface of the suspension 51, so that the force on the circuit board 3 is more balanced.

Furthermore, in the prior art, a circular sleeve 11 is provided on the bottom shell 1, and the circular sleeve 11 is used to connect with the upper shell and other components. In the technical requirements, the pins 31 on the circuit board 3 should be arranged at the center position between the two circular sleeves 11. However, in the process of placing the circuit board 3 on the bottom shell 1, the position of the circuit board 3 is limited only by the limiting portion 24, and the circuit board 3 will still have some small deviation.

Therefore, in the present device, the protection component further includes a limiting column 54, which is evenly distributed on both sides of the pin protection sleeve 52 and is used to penetrate the circular sleeve 11 on the bottom shell 1;

When installing the protection component, if the limiting column 54 passes through the circular sleeve 11, but the pin protection sleeve 52 cannot be buckled on the pin 31, it means that the circuit board 3 is offset. In this way, the circuit board 3 can be moved to insert the pin 31 into the pin protection sleeve 52, so as to adjust the position of the bottom shell 1 and the circuit board 3;

If the limiting column 54 passes through the circular sleeve 11 and the pin protection sleeve 52 is also buckled on the pin 31, it means that the circuit board 3 has not moved and the pin 31 is at the center position between the two circular sleeves 11, which meets the existing assembly technology requirements.

Specifically, the assembly tool includes a quick clamp 4 and a mounting frame 6 that can provide pressure to the suspension 51 in the vertical direction. The quick clamp 4 is an existing tooling technology. The quick clamp is also called a quick clamp and can be purchased.

Specifically, the quick clamp 4 is vertically installed on the inner wall of the mounting frame 6, and the support platform 2 is horizontally installed on the inner bottom surface of the mounting frame 6. The angle between the plane where the quick clamp 4 is located and the plane where the support platform 2 is located is ninety degrees. The pressure rod 41 of the quick clamp 4 is fixedly connected to the lifting plate 61, and a plurality of spring telescopic pressure columns 62 are vertically fixed on the lifting plate 61. One end of the spring telescopic pressure column 62 faces the upper surface of the suspension 51, and is used to flexibly contact the suspension 51 in the vertical direction to gradually apply pressure to the suspension 51 to prevent the suspension 51 from being subjected to excessive pressure in an instant, causing damage to the suspension 51 or the circuit board 3.

The working principle and working process of the present invention are as follows:

First, put the bottom shell 1 into the heating tank 21, then apply epoxy resin on the upper surface of the bottom shell 1, cover the circuit board 3 on the upper surface of the bottom shell 1, and then cover the protective component on the circuit board 3;

When installing the protection component, if the limiting column 54 passes through the circular sleeve 11, but the pin protection sleeve 52 cannot be buckled on the pin 31, it means that the circuit board 3 is offset. In this way, the circuit board 3 can be moved to insert the pin 31 into the pin protection sleeve 52, so as to adjust the position of the bottom shell 1 and the circuit board 3;

If the limiting column 54 penetrates the circular sleeve 11 and the pin protection sleeve 52 is also buckled on the pin 31, it means that the circuit board 3 has not been displaced and the pin 31 is at the center between the two circular sleeves 11, which meets the existing assembly technology requirements;

The quick clamp 4 is started, and the pressure rod 41 of the quick clamp 4 drives the lifting plate 61 and the spring telescopic pressure column 62 on the lifting plate 61 to press down the suspension 51, and gradually apply pressure to the suspension 51 to prevent the suspension 51 from being subjected to excessive pressure in an instant, causing damage to the suspension 51 or the circuit board 3;

Then the electric heating plate 22 in the heating tank 21 is started, the temperature in the heating tank 21 rises, and the epoxy resin is heated. The electric heating plate 22 is electrically connected to a thermocouple sensor 23 for temperature control, so as to ensure the temperature stability during the heating process of the electric heating plate 22. Before the epoxy resin is cured, the spring telescopic pressure column 62 of the lifting plate 61 has been pressing the suspension 51 to prevent the epoxy resin from expanding after being heated, causing bubbles to exist between the bottom shell 1, the epoxy resin, and the circuit board 3, making the bottom shell 1 and the circuit board 3 not firmly bonded, and also preventing the bottom shell 1 and the circuit board 3 from displacement.

The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent.

Claims (1)

1. An assembly method of an inertial measurement unit, characterized in that it comprises the following steps: Step 1, put the bottom shell into the heating tank, then apply epoxy resin on the upper surface of the bottom shell, cover the circuit board on the upper surface of the bottom shell, and then cover the circuit board with a protective component, the protective component includes a pressing block, a pin protection sleeve and a suspension, the suspension is an L-shaped structure, the pin protection sleeve is installed on the inner surface of the suspension and faces the heating tank; the pin protection sleeve is provided with a plurality of protective cavities corresponding to the pins of the circuit board, the pin protection sleeve is sleeved on the pins to prevent the pins from bending during the pressing process, the pressing block is used to abut against the part of the circuit board where the circuit is not designed, so as to realize the pressing of the bottom shell and the circuit board; the protective component also includes limiting columns, the limiting columns are equidistantly distributed on both sides of the pin protection sleeve, and are used to penetrate the circular sleeve on the bottom shell; When installing the protective component, if the limit post passes through the round sleeve, but the pin protective sleeve cannot be buckled on the pin, it means that the circuit board has shifted. In this way, the pin can be inserted into the pin protective sleeve by moving the circuit board to adjust the position of the bottom shell and the circuit board. If the limit post passes through the round sleeve and the pin protective sleeve is also buckled on the pin, it means that the circuit board has not shifted and the pin is in the center between the two round sleeves. Step 2: Assemble the bottom shell and the circuit board; use the quick clamp in the assembly tool to press down the protective component to make the bottom shell, epoxy resin and circuit board in close contact; The quick clamp is vertically mounted on the inner wall of the mounting frame, the assembly tool includes a protective component and a heating component, and a plurality of heating slots are arranged on the support table; The heating assembly includes a support platform, which is horizontally mounted on the inner bottom surface of the mounting frame, the angle between the plane where the quick clamp is located and the plane where the support platform is located is ninety degrees, the pressure rod of the quick clamp is fixedly connected to the lifting plate, and a plurality of spring telescopic pressure columns are vertically fixed on the lifting plate, one end of the spring telescopic pressure column faces the upper surface of the suspension, and is used to flexibly contact the suspension in the vertical direction, gradually apply pressure to the suspension, and prevent the suspension from being subjected to excessive pressure in an instant, causing damage to the suspension or the circuit board; Step 3: heating the part coated with epoxy resin after assembly; the heating tank on the assembly tool is heated up, and the quick clamp in the assembly tool continuously presses down the circuit board until the epoxy resin is cured; A stopper adapted to the contour of the inertial measurement unit is also configured in the heating tank; The inner bottom surface of the heating tank is paved with an electric heating plate as a heat source, and the electric heating plate is electrically connected to a thermocouple sensor for temperature control; The protection component also includes a limiting column and a pressing block. The pressing block is arranged at the bottom of the suspension and is used to abut against a portion of the circuit board where no circuit is designed.