Hidden exhaust high-vacuum sealing structure for instrument

Abstract

The utility model relates to a hidden exhaust high-vacuum sealing structure for an instrument. The sealing ring, the guiding pressing piece and the pressing pushing piece are sequentially installed in an exhaust hole in the instrument shell from inside to outside. The exhaust hole is composed of a small-diameter guide hole section and a large-diameter threaded hole section. The pressing pushing piece is composed of a cylinder part with external threads and a top pressing head part at the front end, and an exhaust channel is formed in the cylinder part in the axial direction. The guide pressing piece is composed of a rear-end cylinder part and a front-end guide head part, and a jacking head insertion hole is formed in the rear end of the rear-end cylinder part; the front end surface of the sealing ring is in pressing contact with the bottom of the exhaust hole, and is sleeved and sealed with the front end guide head part; the guide head part is inserted and matched with the small-diameter guide hole section; the front end of the rear-end cylinder part is in pressing contact with the rear end face of the sealing ring; the cylinder part with the external thread is in threaded connection with the large-diameter threaded hole section; and the top pressure head part is inserted and matched with the top pressure head insertion hole. The structure does not occupy instrument space, and sealing is long-term and reliable.

Description

Technical Field

[0001] The utility model belongs to the technical field of vacuum sealing of inertial elements, and in particular relates to a hidden exhaust high vacuum sealing structure for instruments. Background Art

[0002] The core components of high-precision instruments such as gyroscopes and accelerometers must work in a high vacuum environment so that the movement of their sensitive components has minimal damping and a high Q value, which is a necessary condition for achieving high-precision vacuum instruments. Due to the sensitivity of high-vacuum instruments to vacuum, they have high requirements for sealing and are not allowed to allow any components in the instrument to outgas during long-term operation. Therefore, organic items such as rubber sealing rings are not allowed to be used.

[0003] At present, the sealing of high vacuum instruments after evacuation usually adopts the form of an inflatable nozzle. Specifically, the inflatable nozzle made of soft metal is screwed into the instrument that needs to be evacuated, and then it is fixed and sealed by gluing and welding. When the vacuum device is used to evacuate the instrument through the inflatable nozzle to reach the required vacuum degree, the inflatable nozzle is clamped flat with a bayonet tool, and the excess part is cut off to achieve the purpose of sealing.

[0004] The above measures have the following limitations:

[0005] 1) Improper operation of the bayonet process may cause air leakage in the bayonet part, affecting the accuracy of the instrument;

[0006] 2) The inflation nozzle is not easily removable and cannot be reused, and the process of replacing the nozzle may cause contamination to the instrument;

[0007] 3) There is often a height of (5-10) mm behind the bayonet, which greatly affects the layout of the overall structure and also affects the appearance of the product.

[0008] A hidden structure that does not take up space is a better solution to overcome the above limitations.

[0009] Contents of the utility model

[0010] In view of the deficiencies in the prior art, the utility model proposes a hidden exhaust high vacuum sealing structure for instruments which can realize non-protruding structure packaging of instruments, does not occupy instrument space, is convenient for structural layout, and has long-term and reliable sealing.

[0011] The above-mentioned purpose of the utility model is achieved through the following technical solutions:

[0012] A hidden exhaust high vacuum sealing structure for an instrument comprises a pressing pusher, a guiding pressing pusher and a sealing ring; the sealing ring, the guiding pressing pusher and the pressing pusher are integrally installed in an exhaust hole on an instrument housing in an inner and outer sequential arrangement;

[0013] The exhaust hole is composed of a small-diameter guide hole section and a large-diameter threaded hole section coaxially arranged inside and outside; the pressing pusher is composed of a cylindrical part with an external thread and a top pressure head part coaxially arranged at the front end of the cylindrical part, and an exhaust passage is axially arranged on the cylindrical part; the guide pressing part is composed of a rear cylindrical part and a front guide head part coaxially arranged, and a top pressure head insertion hole is arranged at the rear end of the rear cylindrical part;

[0014] The front end face of the sealing ring is in pressure contact with the bottom of the exhaust hole, and forms a sleeve sealing fit with the front end guide head part; the guide head part of the guide pressing member is plug-fitted with the small diameter guide hole section of the exhaust hole of the instrument case; the front end of the rear end cylindrical part of the guide pressing member is in pressure contact with the rear end face of the sealing ring; the cylindrical part with external threads of the pressing push member is fixedly connected with the large diameter threaded hole section of the exhaust hole of the instrument case through threaded fit; the top pressure head part of the pressing push member is plug-fitted with the top pressure head insertion hole at the rear end of the guide pressing member in a manner that is limited in the axial direction and can rotate relatively along the center axis, and the front end of the top pressure head part is matched with the bottom of the top pressure head insertion hole in a point contact manner.

[0015] Moreover, the top pressure head part is composed of a spherical head located at the front end and a cylindrical neck located at the rear end; the top pressure head insertion hole is composed of a front large-diameter hole section and a rear small-diameter hole section; the spherical head at the front end is inserted into the front large-diameter hole section, and the neck and the rear small-diameter hole section form a clearance fit.

[0016] Moreover, the exhaust passage is composed of a plurality of front exhaust holes located at the front end and a rear exhaust hole located at the center of the rear end; the rear exhaust hole is a square hole or a hexagonal hole that is convenient for inserting a wrench.

[0017] Moreover, the front end guide head portion is composed of a front conical section and a rear cylindrical section.

[0018] Moreover, the pressing pusher and the guide pressing member are both made of hard alloy material; the sealing ring is made of indium sealing ring; and the shell thickness of the small-diameter guide hole section is 0.5-1 mm.

[0019] The advantages and positive effects of the utility model are:

[0020] 1. The utility model compresses the guide pressing member by compressing the pushing member, compresses the sealing ring by the guide pressing, and realizes the position of the exhaust hole on the instrument housing through the deformation of the sealing ring, thereby realizing the sealing of the exhaust hole.

[0021] 2. After the sealing structure is used to seal the instrument, the sealing structure is hidden in the exhaust hole, does not occupy the inner and outer space of the meter body, and has no effect on the appearance of the meter body; in addition, the sealing structure is a metal seal with good sealing performance, high temperature resistance, and no gas escape, which is conducive to long-term high vacuum maintenance and sealing of the instrument.

[0022] 3. The sealing structure can be disassembled by loosening the pressing pusher, which is convenient for disassembly and can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a reference diagram of the exhaust state of the utility model before sealing;

[0024] Figure 2 This is a schematic diagram of the structure of the utility model when entering a sealed state;

[0025] Figure 3 It is a structural schematic diagram of the compacting pusher of the utility model, 3a, rear view; 3b, longitudinal sectional view;

[0026] Figure 4 It is a structural schematic diagram of the guide pressing member of the utility model, 4a, rear view; 4b, longitudinal sectional view;

[0027] Figure 5 It is a structural schematic diagram of the sealing ring of the utility model;

[0028] Figure 6 It is a schematic diagram of the combined structure of the pressing and pushing member and the guiding pressing member of the utility model. DETAILED DESCRIPTION

[0029] The structure of the utility model is further described below with reference to the accompanying drawings and through embodiments. It should be noted that the embodiments are descriptive rather than restrictive.

[0030] A hidden exhaust high vacuum sealing structure for instruments, see Figure 1-Figure 6 The invention point is: the sealing structure includes a pressing pusher 4, a guide pressing member 3 and a sealing ring 2. The sealing structure is integrally mounted on the exhaust hole provided on the instrument housing 1, and the exhaust hole is composed of a small-diameter guide hole section and a large-diameter threaded hole section coaxially provided inside and outside. The shell thickness of the small-diameter guide hole section is controlled to be about 0.5-1 mm, which can support the extrusion force of the sealing ring.

[0031] The pressing pusher is composed of a cylindrical part 4.1 with external threads and a top pressure head part 4.2 coaxially arranged at the front end of the cylinder. The size of the cylindrical part matches the size of the large diameter threaded hole section of the exhaust hole, and the two can form a threaded connection. The radial size of the top pressure head part is smaller than the radial size of the cylindrical part. The top pressure head part is composed of a spherical head 4.2.1 located at the front end and a cylindrical neck 4.2.2 located at the rear end, and the radial size of the neck is slightly smaller than the size of the spherical head. An exhaust passage is axially arranged on the cylindrical part. The exhaust passage is composed of a plurality of front exhaust holes 4.1.1 located at the front end and a rear exhaust hole 4.1.2 located at the center of the rear end. In order to achieve exhaust and facilitate the screwing of the pressing pusher in the seal installation of the instrument housing, the rear exhaust hole can be a square hole as described in the attached figure, or a hexagonal hole, etc., to facilitate the insertion of a wrench for screwing.

[0032] The guide clamp is composed of a rear cylindrical portion 3.1 and a coaxially arranged front guide head portion 3.2. The outer diameter of the rear cylindrical portion is slightly smaller than the aperture of the large diameter threaded hole section of the exhaust hole, so that the guide clamp can be inserted into the exhaust hole in a clearance fit manner. The front guide head portion is composed of a front conical section 3.2.1 and a rear cylindrical section 3.2.2. The radial size of the front conical section is smaller than the aperture of the small diameter guide hole section of the exhaust hole, and the size of the rear cylindrical section is clearance fit with the aperture of the small diameter guide hole section of the exhaust hole. A top pressure head insertion hole is provided at the rear end of the rear cylindrical part, and the top pressure head insertion hole is composed of a front large-diameter hole section 3.1.1 and a rear small-diameter hole section 3.1.2. The aperture of the front large-diameter hole section is slightly larger than the maximum size of the spherical head of the top head part, and its depth is larger than the axial size of the spherical head. The aperture size of the rear small-diameter hole section is slightly smaller than the maximum size of the spherical head. When the guide pressing member and the pressing pusher are assembled, the spherical head passes through the rear small-diameter hole section in a small interference fit and is inserted into the large-diameter hole at the front end, and then axial limiting is achieved.

[0033] The above-mentioned pressing and pushing member and the guiding pressing member are both made of hard alloy material.

[0034] The sealing ring adopts an indium sealing ring. Metal indium has good ductility and is very suitable for high vacuum sealing connection. Compared with rubber, it has a larger gas outflow rate and permeability, and is not resistant to high temperature and radiation. Indium sealing makes up for the above shortcomings and has significant advantages. The inner diameter of the indium sealing ring is slightly larger than the diameter of the rear end cylindrical section of the guide head part. The outer diameter of the indium sealing ring is slightly smaller than the aperture of the large diameter threaded hole section of the exhaust hole.

[0035] The above-mentioned sealing ring, guide pressing member and pressing push member are hidden and installed in the exhaust hole of the instrument case in an inner and outer sequential manner; the front end face of the sealing ring is pressed and contacted with the bottom of the exhaust hole, and forms a sleeve sealing fit with the rear cylindrical section of the front end guide head part; the guide head part of the guide pressing member is inserted and matched with the small diameter guide hole section of the exhaust hole of the instrument case, which can avoid the deviation of the guide pressing member during the installation of the sealing structure, resulting in uneven force on the indium sealing ring. The front end of the rear end cylindrical part of the guide pressing member forms a pressing contact with the rear end surface of the sealing ring; the cylindrical part with external threads of the pressing push member and the large diameter threaded hole section of the exhaust hole of the instrument case form a fixed connection through threaded cooperation, and the top pressure head part of the pressing push member is limited in the axial direction and can rotate relatively along the center axis to form a plug-in cooperation with the top pressure head insertion hole at the rear end of the guide pressing member, and the front end of the top pressure head part cooperates with the bottom of the top pressure head insertion hole in a point contact manner, so that the pressing push member only provides the previous pressing force to the guide pressing member, and does not provide torque to the guide pressing member, so it will not cause rotation to the indium sealing ring and destroy its structure.

[0036] The process of vacuum sealing the instrument using the above-mentioned hidden exhaust high vacuum sealing structure is as follows:

[0037] Step 1: First, press the guide pressing member and the pressing pusher together, so that the top pressing head of the pressing pusher is pressed into the top pressing head insertion hole on the guide pressing member, and the two form a combination that can rotate relatively along the circumferential direction along the axis limit, such as Figure 6 As shown;

[0038] Step 2: Place the sealing ring into the exhaust hole on the case of the instrument to be vacuumed;

[0039] Step 3: Screw the assembly formed in step 1 into the exhaust hole on the watch case. At this time, only about 1 / 3 of the way is needed to facilitate subsequent tool operation. Figure 1 As shown, a complete airway is formed through the small-diameter guide hole section on the instrument case, the gap between the sealing ring and the front guide head part, the gap between the rear cylindrical part of the guide pressing member and the large-diameter threaded hole section on the instrument case, and the exhaust passage on the pressing pusher. In this state, the instrument is placed in the exhaust device for evacuation, so that the gas in the instrument is discharged through the complete airway.

[0040] Step 4. After the instrument is exhausted, continue to screw in the guide clamping piece, compress the sealing ring through the guide clamping piece, and insert the front guide head of the guide clamping piece into the small diameter guide hole section on the instrument case to play a guiding role until the guide clamping piece is completely tightened and the sealing ring is deformed, completely closing the exhaust airway in the exhaust device, thereby playing a sealing role.

[0041] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A hidden exhaust high vacuum sealing structure for an instrument, characterized in that: It includes a pressing and pushing member, a guiding pressing member and a sealing ring; the sealing ring, the guiding pressing member and the pressing and pushing member are integrally installed in the exhaust hole on the instrument housing in a manner of being arranged inside and outside in sequence; The exhaust hole is composed of a small-diameter guide hole section and a large-diameter threaded hole section coaxially arranged inside and outside; the pressing pusher is composed of a cylindrical part with an external thread and a top pressure head part coaxially arranged at the front end of the cylindrical part, and an exhaust passage is axially arranged on the cylindrical part; the guide pressing part is composed of a rear cylindrical part and a front guide head part coaxially arranged, and a top pressure head insertion hole is arranged at the rear end of the rear cylindrical part; The front end face of the sealing ring is in pressure contact with the bottom of the exhaust hole, and forms a sleeve sealing fit with the front end guide head part; the guide head part of the guide pressing member is plug-fitted with the small diameter guide hole section of the exhaust hole of the instrument case; the front end of the rear end cylindrical part of the guide pressing member is in pressure contact with the rear end face of the sealing ring; the cylindrical part with external threads of the pressing push member is fixedly connected with the large diameter threaded hole section of the exhaust hole of the instrument case through threaded fit; the top pressure head part of the pressing push member is plug-fitted with the top pressure head insertion hole at the rear end of the guide pressing member in a manner that is limited in the axial direction and can rotate relatively along the center axis, and the front end of the top pressure head part is matched with the bottom of the top pressure head insertion hole in a point contact manner.

2. The hidden exhaust high vacuum sealing structure for instruments according to claim 1 is characterized in that: The ram head portion is composed of a spherical head at the front end and a cylindrical neck at the rear end; the ram head insertion hole is composed of a front large-diameter hole section and a rear small-diameter hole section; the spherical head at the front end is inserted into the front large-diameter hole section, and the neck and the rear small-diameter hole section form a clearance fit.

3. The hidden exhaust high vacuum sealing structure for instruments according to claim 1 is characterized in that: The exhaust passage is composed of a plurality of front exhaust holes at the front end and a rear exhaust hole at the center of the rear end; the rear exhaust hole is a square hole or a hexagonal hole that is convenient for inserting a wrench.

4. The hidden exhaust high vacuum sealing structure for instruments according to claim 1, characterized in that: The front end guide head portion is composed of a front conical section and a rear cylindrical section.

5. The hidden exhaust high vacuum sealing structure for instruments according to claim 1, characterized in that: The pressing pusher and the guide pressing member are both made of hard alloy material; the sealing ring is made of indium sealing ring.

6. The hidden exhaust high vacuum sealing structure for instruments according to claim 1, characterized in that: The shell thickness of the small-diameter guide hole section is 0.5-1 mm.

Images