Air pressure type pin inserting and pulling method

Abstract

The invention discloses an air pressure type pin inserting and pulling method. The method comprises the following specific operation steps that (1) the length of a pin shaft of a positioning pin is determined according to the designed depth of a pin hole; the depth of the pin hole-the length of the pin shaft is greater than or equal to 5mm; 2) processing a positioning pin; (3) when the positioning pin is installed, cleaning the outer circle of the pin shaft and the inner wall of the pin hole by using cleaning cloth, and inserting the pin shaft into the pin hole and tightly attaching the pin shaft to the hole wall; a high-pressure connector is installed on the pin shaft, air in a closed space defined by the pin shaft and the pin hole is extracted, and under the action of atmospheric high pressure, the positioning pin is pushed to extrude the inner wall of the pin hole, and fixing and positioning are achieved; when the positioning pin is taken out, a high-pressure joint is mounted on the pin shaft; and high-pressure gas is injected into a closed space defined by the pin shaft and the pin hole, so that the positioning pin is extruded out of the pin hole. The method is convenient to operate; due to the fact that no mechanical impact force or vibration exists in the operation process, the parts are not prone to being damaged or damaged by the impact force or the vibration, and it can be guaranteed that all the installed parts are reset accurately.

Description

Technical Field

[0001] The invention relates to a pneumatic pin plugging and pulling method. Background Art

[0002] During the installation and removal of the locating pin, since the locating pin and the pin hole adopt transition or conical extrusion fit, there is extrusion friction between the hole and the shaft after the locating pin is installed, and the locating pin is difficult to remove. Standard locating pins generally use internal thread connection screws, and the impact inertia force of the pin puller overcomes the friction to pull out the locating pin, such as Figure 1 As shown, the existing pin puller uses the impact force of a heavy hammer 4 to pull out the positioning pin 5, and the heavy hammer 4 is arranged on the pin pulling rod 6. However, this often causes the damage of the thread so that the positioning pin cannot be taken out, and the positioned parts are scrapped, causing greater economic losses. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a pneumatic pin insertion and extraction method which is easy to operate and will not cause the parts being assembled to be scrapped or damaged.

[0004] The technical solution adopted by the present invention is: a pneumatic pin insertion and extraction method, characterized in that: the positioning pin adopted by the present invention comprises a pin shaft and a high-pressure gas joint; the pin shaft is conical, an air inlet hole arranged along the axial direction is provided at the center of the pin shaft, and the high-pressure gas joint is fixedly installed on the upper end of the air inlet hole; The specific operations are as follows: 1) First, determine the pin shaft length of the positioning pin according to the designed pin hole depth; the pin hole depth - pin shaft length ≥ 5mm; 2) Processing positioning pins; 3) When installing the locating pin, use a rag to clean the outer circle of the pin shaft and the inner wall of the pin hole, insert the pin shaft into the pin hole and make it close to the hole wall; install a high-pressure joint on the pin shaft to extract the air in the closed space surrounded by the pin shaft and the pin hole. Under the action of the atmospheric high pressure, the locating pin and the inner wall of the pin hole are pushed to produce extrusion and achieve fixation and positioning; When taking out the locating pin, install a high-pressure joint on the pin shaft; inject high-pressure gas into the closed space surrounded by the pin shaft and the pin hole, the locating pin is pushed out of the pin and separated from the hole wall, so that the locating pin is extruded from the pin hole.

[0005] Furthermore, in step 3), when installing the positioning pin, when the pressure in the closed space surrounded by the pin shaft and the pin hole is less than 0.1MPa, the extraction is stopped.

[0006] Furthermore, in step 3), when the positioning pin is removed, when the internal pressure of the closed space surrounded by the pin shaft and the pin hole reaches 2.3-2.6 MPa, the gas source is disconnected.

[0007] Furthermore, the upper diameter of the air inlet hole is larger than the lower diameter, and the upper part of the air inlet hole is a threaded hole, and the high-pressure gas connector is threadedly connected to the top of the air inlet hole.

[0008] Furthermore, the diameter of the lower portion of the air inlet hole is Φ0.5~Φ1mm.

[0009] Compared with the prior art, the present invention has the following beneficial effects: When the present invention is used, it is only necessary to input high-pressure gas into the air inlet or extract gas to squeeze out or insert the positioning pin from the pin hole, which is easy to operate. Since there is no mechanical impact force and vibration during the operation of the present invention, it is suitable for installing and removing positioning pins when assembling parts of precision mechanical structures, and it is not easy to cause damage and destruction of parts due to impact force and vibration. Moreover, it can ensure the accurate reset of each installed part, reducing the installation and debugging time and installation labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is an existing heavy hammer type pin puller structure diagram.

[0011] Figure 2 It is an installation structure diagram of the positioning pin adopted in the present invention. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with the accompanying drawings.

[0013] like Figure 2 As shown, the positioning pin used in the present invention includes a pin shaft 1 and a high-pressure gas connector 2; the pin shaft 1 is conical, and an axially arranged air inlet hole 11 is provided at the center of the pin shaft 1, and the high-pressure gas connector 2 is fixedly installed at the upper end of the air inlet hole 11.

[0014] The upper diameter of the air inlet hole 11 is larger than the lower diameter, and the lower diameter of the air inlet hole is Φ0.5-Φ1 mm. The upper part of the air inlet hole 11 is a threaded hole, and the high-pressure gas connector 2 is threadedly connected to the upper part of the air inlet hole 11.

[0015] The principle of the present invention is to utilize the closed space formed by the lower end of the pin shaft 1 and the pin hole 3, inject high-pressure gas into the closed space through the air inlet 11 or evacuate the space, and remove or install the pin shaft 1 through the action of gas pressure.

[0016] The present invention comprises the following steps: 1) First, determine the length of the pin shaft 1 of the positioning pin according to the depth of the designed pin hole 3; the depth of the pin hole - the length of the pin shaft ≥ 5mm; 2) Processing positioning pins; 3) When installing the locating pin; (a) Use a rag to clean the outer circle of the pin shaft 1 and the inner wall of the pin hole 3 to avoid excessive surface impurities affecting its sealing; (b) Insert the pin shaft 1 into the pin hole and fit it tightly against the hole wall; Install the high-pressure joint 2 and tighten the high-pressure joint to ensure its sealing; (c) Extract the air from the closed space surrounded by the pin shaft 1 and the pin hole 3. Under the action of the atmospheric high pressure, the locating pin and the inner wall of the pin hole are pushed to produce compression and achieve fixation and positioning; when the pressure in the closed space surrounded by the pin shaft 1 and the pin hole 3 is <0.1MPa, stop extracting.

[0017] When removing the locating pin: (A) Install the high-pressure air joint and tighten it to ensure its sealing; (B) Inject high-pressure air into the closed space surrounded by the pin shaft and the pin hole; (C) When the internal pressure of the closed space surrounded by the pin shaft 1 and the pin hole 3 reaches 2.3-2.6MPa, the locating pin will loosen, the locating pin plug will lose contact with the inner wall of the pin hole, and the air source will be disconnected.

Claims

1. A pneumatic pin insertion and extraction method, characterized in that: The positioning pin used includes a pin shaft and a high-pressure gas joint; the pin shaft is conical, and an air inlet hole arranged along the axial direction is provided at the center of the pin shaft, and the high-pressure gas joint is fixedly installed on the upper end of the air inlet hole; The specific operations are as follows: 1) First, determine the pin shaft length of the positioning pin according to the designed pin hole depth; the pin hole depth - pin shaft length ≥ 5mm; 2) Processing positioning pins; 3) When installing the locating pin, use a rag to clean the outer circle of the pin shaft and the inner wall of the pin hole, insert the pin shaft into the pin hole and make it close to the hole wall; install a high-pressure joint on the pin shaft to extract the air in the closed space surrounded by the pin shaft and the pin hole. Under the action of the atmospheric high pressure, the locating pin and the inner wall of the pin hole are pushed to produce extrusion and achieve fixation and positioning; When taking out the locating pin, install a high-pressure joint on the pin shaft; inject high-pressure gas into the closed space surrounded by the pin shaft and the pin hole, the locating pin is pushed out of the pin and separated from the hole wall, so that the locating pin is extruded from the pin hole.

2. According to the pneumatic pin insertion and extraction method of claim 1, in step 3), when installing the positioning pin, when the pressure in the closed space surrounded by the pin shaft and the pin hole is less than 0.1MPa, the extraction is stopped.

3. The pneumatic pin insertion and extraction method according to claim 1 is characterized in that: In step 3), when removing the positioning pin, when the internal pressure of the closed space surrounded by the pin shaft and the pin hole reaches 2.3-2.6MPa, disconnect the air source.

4. The pneumatic pin insertion and extraction method according to claim 1, characterized in that: The upper diameter of the air inlet hole is larger than the lower diameter, and the upper part of the air inlet hole is a threaded hole, and the high-pressure gas joint is threadedly connected to the top of the air inlet hole.

5. The pneumatic pin insertion and extraction method according to claim 2, characterized in that: The diameter of the lower part of the air inlet hole is Φ0.5~Φ1mm.

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