Self-positioning pin

Abstract

The utility model provides a self-positioning pin, and belongs to the technical field of pin connection. The problems that when a pin enters a pin hole, internal gas cannot be discharged smoothly, accurate positioning of parts cannot be met, and assembly and disassembly are difficult are solved. The pin comprises a pin body and an air hole, the pin body is arranged in a pin hole of a part to be assembled, the pin body is of an integrally-formed structure, one end of the pin body is a cone, the other end of the pin body is a cylinder, inner threaded holes are formed in the upper end face and the lower end face of the pin body, and the air hole is formed in the pin body along the vertical center line. The air holes are communicated with the internal threaded holes formed in the two end faces. The device is mainly used for assembling and positioning, can also be used as a connecting part, and can also be used as an overload shearing element in a mounting device.

Description

Technical Field

[0001] This utility model belongs to the field of pin connection technology, and in particular relates to a self-positioning pin. Background Technology

[0002] Pin connections are a simple and effective mechanical connection method that uses cylindrical pins, tapered pins, slotted pins, etc., to fix or connect two or more components. Pin connections are widely used in various industrial and engineering fields, favored for their simple structure, ease of installation and disassembly, and low cost. With technological advancements, people have higher demands for precision instruments, which indirectly leads to higher requirements for the positioning accuracy and ease of assembly of pin connections.

[0003] Cylindrical pins and tapered pins are commonly used connecting pins. Cylindrical pins are mainly used for positioning, ensuring accurate relative positioning between two parts. Tapered pins are mainly used in parts that require frequent disassembly, offering good self-locking properties. However, in precision parts assembly, the single-sided clearance between the pin and the pin hole is very small, reaching the level of 0.1mm. Due to this extremely small clearance, air inside the pin cannot escape smoothly when it enters the hole, affecting assembly efficiency. Furthermore, large parts are large and heavy. When two cylindrical pins are used for positioning within a plane, it is difficult to flexibly adjust the large parts to their accurate relative positions for assembly. In other words, tapered pins cannot meet the accurate positioning requirements, often requiring a compromise hole enlargement principle to achieve a single-sided clearance of approximately 0.05mm to 0.1mm. The problem with this assembly method is that in subsequent processing or secondary assembly, the positional accuracy cannot be guaranteed to be the same as the previous assembly, and the resulting positional error will affect the overall performance of the machine. Utility Model Content

[0004] In view of this, the present invention aims to propose a self-positioning pin to solve the problems that the internal gas cannot be smoothly discharged when the pin enters the pin hole, and that it cannot meet the requirements for accurate positioning of parts and difficulty in loading and unloading.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a self-positioning pin, comprising a pin body and a vent hole, wherein the pin body is disposed in the pin hole of the part to be assembled, the pin body is an integrally formed structure, one end of the pin body is a cone and the other end is a cylinder, both the upper and lower end faces of the pin body are provided with internal thread holes, and the pin body is provided with a vent hole along the vertical center line, the vent hole communicating with the internal thread holes provided on the two end faces.

[0006] Furthermore, the assembly to be assembled consists of two parts, and pin holes are provided on the connecting surfaces of the two parts. The pin holes are correspondingly arranged, and the pin body is disposed in the pin holes.

[0007] Furthermore, the internal threaded hole includes a first threaded hole and a second threaded hole. The first threaded hole is disposed in the upper end face of the cone, and the second threaded hole is disposed in the lower end face of the cylinder. The first threaded hole and the second threaded hole are coaxial and both communicate with the vent hole.

[0008] Furthermore, the height of the pin body is 1-2 mm less than the total depth of the pin hole.

[0009] Furthermore, the height of the pin body is greater than the depth of one side of the pin hole.

[0010] Furthermore, the taper of the cone is 1:16.

[0011] Furthermore, the pin hole and the pin body adopt a transition fit with a fit tolerance of H7 / h6, the tolerance grade of the pin body diameter is h6, and the tolerance grade of the pin hole inner diameter is H7.

[0012] Furthermore, the pin is made of 45 steel and has a smooth outer surface.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. This utility model is specifically designed for large equipment with high positional accuracy requirements, and can assemble parts on pins and pin holes with smaller tolerance range;

[0015] 2. This utility model not only meets the requirements for providing high positional accuracy positioning, but also has the characteristics of automatic centering, simple structure, and convenient loading and unloading;

[0016] 3. This utility model sets the pin body into two parts, a column and a cone, so that the pin body can automatically align with the center when inserted into the pin hole, and provides stable positioning after assembly.

[0017] 4. This utility model makes disassembly more convenient by providing internal threaded holes on the upper and lower end faces of the pin body;

[0018] 5. The ventilation hole on the center line of the pin body of this utility model helps to expel air during the assembly process, reduce friction and resistance, and allow the gas inside the pin hole to be discharged smoothly. This can avoid the gas sealing caused by the tight fit between the pin and the pin hole, which affects the assembly efficiency. Attached Figure Description

[0019] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0020] Figure 1 This is a schematic diagram of the axial structure of a self-positioning pin according to the present invention.

[0021] Figure 2 This is a cross-sectional structural diagram of a self-positioning pin according to the present invention.

[0022] Figure 3 This is a schematic diagram of the connection structure between a self-positioning pin and a component to be assembled according to the present invention.

[0023] Figure 4 This is a flowchart illustrating the use of a self-positioning pin as described in this utility model.

[0024] In the picture:

[0025] 1. Pin body; 2. First threaded hole; 3. Vent hole; 4. Second threaded hole; 5. Part to be assembled. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present utility model can be combined with each other, and the described embodiments are only some embodiments of the present utility model, not all embodiments.

[0027] See Figure 1-3 This embodiment describes a self-positioning pin, which includes a pin body 1 and a vent hole 3. The pin body 1 is disposed in the pin hole of the component 5 to be assembled. The pin body 1 is an integrally formed structure, with one end being a cone and the other end being a cylinder. By setting one end of the pin body 1 as a cone and the other end as a cylinder, the pin body 1 can automatically align with the center when inserted into the pin hole and provide stable positioning after assembly, reducing the alignment difficulty and assembly time during the assembly process. The upper and lower end faces of the pin body 1 are provided with internal threaded holes, which make disassembly more convenient. The pin body 1 is provided with a vent hole 3 along the vertical center line, and the vent hole 3 communicates with the internal threaded holes on the two end faces. The vent hole helps to expel air during the assembly process, making it easier for the pin body 1 to be inserted into the pin hole.

[0028] The pin is mainly used for assembly positioning, and can also be used as a connecting part. It can also be used as an overload shearing element in the installation device. The pin body 1 in this utility model is mainly used for large equipment with high positional positioning requirements. The cylindrical part of the pin body 1 provides positioning function for the part, and the conical part provides assembly guidance for the part. The vent hole 3 is used to discharge the air in the pin hole, thereby improving assembly efficiency. Because this utility model is suitable for the assembly of high-precision parts, the size of the pin body 1 is small and it is not convenient to remove it when disassembling. Therefore, internal threaded holes are provided at the upper and lower ends of the pin body 1. When disassembling, the bolt is screwed into the exposed internal threaded hole, and the pin body 1 is removed from the pin hole by the bolt.

[0029] The component 5 to be assembled consists of two parts, and pin holes are opened on the connecting surfaces of the two parts of the component 5 to be assembled. The pin holes are set accordingly, and the pin body 1 is set in the pin hole.

[0030] The internal threaded hole includes a first threaded hole 2 and a second threaded hole 4. The first threaded hole 2 is located inside the upper end face of the cone body, and the second threaded hole 4 is located inside the lower end face of the column body. The first threaded hole 2 and the second threaded hole 3 are coaxial and both communicate with the vent hole 3.

[0031] The height of the pin 1 is 1-2 mm less than the total depth of the pin hole, ensuring that the pin 1 will not be completely inserted into the pin hole, thus preventing disassembly difficulties or damage caused by the pin 1 being too tightly fitted to the pin hole.

[0032] The height of the pin 1 is greater than the depth of one side of the pin hole, and the positioning of the connecting surface of the component 5 to be assembled is provided by the column part in the pin 1.

[0033] The cone has a taper of 1:16, which helps to reduce friction and stress concentration during assembly.

[0034] The pin hole and pin body 1 adopt a transition fit with a fit tolerance of H7 / h6. The tolerance grade of the pin body diameter is h6, and the tolerance grade of the pin hole inner diameter is H7. The positional accuracy is ensured through the transition fit.

[0035] The pin 1 is made of 45 steel, which ensures that the pin 1 has sufficient strength and toughness. The outer surface of the pin 1 is smooth, which reduces friction during installation and disassembly, making it easy to install and disassemble.

[0036] See Figure 1-4 This embodiment describes a method for using a self-locating pin, comprising the following steps:

[0037] Step 1: Measure the dimensions of the pin hole and design the dimensions of the self-locating pin based on these dimensions. The pin body 1 should be 1-2 mm smaller than the total depth of the pin hole. The height of the cylindrical portion of the pin body 1 should be greater than half the total depth of the pin hole. The taper of the conical portion of the pin body should be 1:16. The formula for calculating the strength of the pin connection is as follows: Where F is the transverse shear force, d is the diameter of pin 1, Z is the number of pins, and τ p =80MPa, the dimensions of the internal thread hole and the vent hole 3 are designed according to the actual dimensions.

[0038] Step 2: Place the cylindrical part of the designed pin 1 into the pin hole of one of the parts of the workpiece 5 to be assembled, with the cylindrical part facing down. Then align the pin hole of the other part of the workpiece 5 to be assembled with the conical part of the pin 1, and slowly bring them close together for assembly. Since the size of the conical end is smaller than the size of the pin hole, it is easy to align. The positioning of the workpiece 5 to be assembled is provided by the cylindrical part of the pin 1, and the conical part of the pin 1 plays an automatic centering role during the assembly process.

[0039] Step 3: When disassembly is required, take out the part on one side of the workpiece 5 to be assembled, and screw the bolt into the internal threaded hole to facilitate the removal of the pin 1 from the pin hole. Since it is uncertain whether the column part or the cone part of the pin 1 will be exposed during the disassembly process of the workpiece 5 connected by the pin 1, internal threaded holes are provided in both the column part and the pin part to facilitate the screwing in of the bolt to remove the pin 1.

[0040] Example 1: In a gas compressor, the intermediate housing needs to be split in half and the separated intermediate housing needs to be positioned and assembled. The design pin hole has an inner diameter of 16mm, a total depth of 44mm, a single-sided pin hole depth of 22mm, and an inner diameter tolerance of 0 to +0.018. The height of the cylindrical part of pin 1 is 27mm, the outer diameter is 16mm, the outer diameter of the small end of the conical part is 15mm, the internal thread diameter is 4mm, the inner diameter of the air guide hole is 1mm, and the outer surface tolerance of the cylindrical part is -0.011 to 0. Therefore, the positioning gap is 0 to 0.029mm, and the single-sided gap is 0.0145mm. Thus, the assembly error is approximately 0.015mm. When the 16mm pin hole contacts the 15mm conical part, i.e., when the error is 0.5mm, assembly can be achieved. After assembly, the relative error between the two parts is approximately 0.015mm.

[0041] The embodiments of the present invention disclosed above are merely illustrative of the present invention. The embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention.

Claims

1. A self-locating pin, characterized in that: It includes a pin (1) and a vent hole (3). The pin (1) is set in the pin hole of the part to be assembled (5). The pin (1) is an integrally formed structure. One end of the pin (1) is a cone and the other end is a cylinder. The upper and lower end faces of the pin (1) are provided with internal thread holes. The pin (1) is provided with a vent hole (3) along the vertical center line. The vent hole (3) is connected to the internal thread holes provided on the two end faces.

2. A self-positioning pin according to claim 1, characterized in that: The component to be assembled (5) consists of two parts. Pin holes are opened on the connecting surfaces of the two parts of the component to be assembled (5). The pin holes are set accordingly, and the pin body (1) is set in the pin hole.

3. A self-positioning pin according to claim 1, characterized in that: The internal threaded hole includes a first threaded hole (2) and a second threaded hole (4). The first threaded hole (2) is located in the upper end face of the cone, and the second threaded hole (4) is located in the lower end face of the column. The first threaded hole (2) and the second threaded hole (4) are coaxial and both communicate with the vent hole (3).

4. A self-positioning pin according to claim 3, characterized in that: The height of the pin (1) is 1-2 mm less than the total depth of the pin hole.

5. A self-positioning pin according to claim 1, characterized in that: The height of the pin (1) is greater than the depth of one side of the pin hole.

6. A self-positioning pin according to claim 1, characterized in that: The taper of the cone is 1:

16.

7. A self-positioning pin according to claim 1, characterized in that: The pin hole and the pin body (1) adopt a transition fit with a fit tolerance of H7 / h6. The tolerance grade of the pin body diameter is h6, and the tolerance grade of the pin hole inner diameter is H7.

8. A self-positioning pin according to claim 1, characterized in that: The pin (1) is made of 45 steel and has a smooth outer surface.

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