Delicate precision pressure gauge

Abstract

This invention relates to the field of pressure testing instrument technology, and particularly to a compact precision pressure gauge, comprising a housing assembly and a movement assembly mounted on the housing assembly. The movement assembly includes a movement base and a main movement mounted on the movement base. A central shaft is mounted on the main movement, and a pointer is fixed to the front end of the central shaft. A label located behind the pointer is provided on the periphery of the central shaft, which can be rotated for zeroing and can be locked. The label is mounted on the periphery of the central shaft by an axial elastic locking and limiting mechanism. The label is provided with a non-contact driven component for non-contact rotational zeroing of the label. The gauge has a compact structure, good sealing performance, can perform non-contact zeroing, and can reliably lock the label after zeroing.

Description

Technical Field

[0001] This invention relates to the field of pressure detection instrument technology, and in particular to a compact precision pressure gauge. Background Technology

[0002] A pressure gauge is an instrument used to detect the pressure value of pressure media such as gases and liquids. It typically includes a housing, a pressure-sensitive element, a transmission mechanism, a central shaft, a pointer, and a pressure-gradient plate. After the pressure medium enters the pressure-sensitive element through the pressure medium interface, the pressure-sensitive element generates a mechanical deformation corresponding to the medium pressure. This mechanical deformation is amplified by the transmission mechanism and drives the central shaft and pointer to rotate. The position of the pointer relative to the scale on the plate indicates the measured pressure value.

[0003] During manufacturing, transportation, installation, and long-term use, pressure gauges may be affected by factors such as assembly errors in the movement, residual deformation of elastic elements, changes in ambient temperature, vibration and shock, or wear of parts. These factors can cause the pointer of the pressure gauge to not accurately point to the zero mark on the label when there is no pressure. To ensure the measurement accuracy of the pressure gauge, zero-point calibration is necessary.

[0004] The existing methods for zeroing pressure gauges typically include the following:

[0005] Remove the front cover or transparent panel of the pressure gauge and directly rotate the label or adjust the pointer;

[0006] A through-hole adjustment hole is provided on the housing, and adjustment is made by entering the housing through mechanical structures such as screws and levers.

[0007] Disassemble and reinstall the pointer directly, so that it is aligned with the zero mark again;

[0008] The movement zero position is adjusted through complex gear, eccentric shaft, or threaded transmission mechanisms.

[0009] The above-mentioned zeroing methods have certain shortcomings. Removing the transparent panel will damage the original sealing of the pressure gauge, making it easy for dust, moisture, or corrosive media to enter the housing; the through-hole adjustment hole increases the difficulty of sealing the housing; repeated disassembly and reassembly of the pointer can easily damage the central shaft or change the preload of the movement; using a complex mechanical zeroing mechanism will increase the axial and radial dimensions of the pressure gauge, which is not conducive to the miniaturization and weight reduction of the pressure gauge. In addition, after the traditional nameplate has been rotated for zeroing, if there is no reliable locking structure, it may circumferentially deflect when the equipment vibrates or is subjected to impact, thus causing zeroing error again. Summary of the Invention

[0010] Especially in environments where high requirements are placed on sealing, size, and accuracy, there is a need for a compact precision pressure gauge that can perform non-contact zeroing while keeping the housing sealed, and can reliably lock the nameplate after zeroing.

[0011] The purpose of this invention is to provide a compact precision pressure gauge. By setting a non-contact driven component on the nameplate and clamping the nameplate with an axial elastic locking limit mechanism, the nameplate can rotate around the central axis to zero when subjected to a sufficiently large non-contact driving force. After the non-contact driving force disappears, it can maintain its current position by relying on the friction force generated by the axial elastic locking limit mechanism, thereby taking into account both the convenience of zeroing operation and the stability of the position after zeroing.

[0012] Another objective of this invention is to drive the nameplate to rotate from the outside of the pressure gauge without disassembling the pre-sealed visual component or damaging the pressure gauge's sealing condition, thereby reducing the possibility of dust, moisture, and other contaminants entering the pressure gauge's interior.

[0013] Another objective of this invention is to form a compact nameplate mounting and locking structure by means of a positioning sleeve, a front limiting rigid baffle, a rear limiting elastic baffle, a C-shaped reinforcing plate, and an outer peripheral annular limiting pad, making the structure suitable for precision pressure gauges with small internal spaces.

[0014] Another object of the present invention is to improve the ease of assembly, sealing and lightweighting of the pressure gauge by means of a front-to-back separated internal space, a detachable front sealing and viewing component and an engineering plastic housing structure.

[0015] The above-mentioned objective of the present invention is achieved through the following technical solution: a compact precision pressure gauge, comprising a housing assembly and a movement assembly mounted on the housing assembly, the movement assembly comprising a movement base and a main movement mounted on the movement base, a central shaft being assembled and connected on the main movement, a pointer being fixed at the front end of the central shaft, a label located behind the pointer being provided on the periphery of the central shaft being rotatable for zeroing and being lockable, the label being mounted on the periphery of the central shaft by an axial elastic locking and limiting mechanism, and a non-contact driven component being provided on the label for non-contact driving of the label for rotational zeroing.

[0016] As a preferred embodiment of the present invention, the axial elastic locking and limiting mechanism includes a front limiting blocking component and a rear limiting blocking component located around the central shaft and arranged at intervals in the axial direction of the central shaft, wherein at least one of the front limiting blocking component and the rear limiting blocking component is an axially elastic component.

[0017] As a preferred embodiment of the present invention, the front limiting blocking assembly includes a front limiting rigid baffle, the rear limiting blocking assembly includes a rear limiting elastic baffle, the rear limiting elastic baffle is capable of having an elastic force in the axial direction, and the nameplate is sandwiched between the front limiting rigid baffle and the rear limiting elastic baffle.

[0018] As a preferred embodiment of the present invention, the outer casing assembly includes a main casing with openings at both the front and rear. An internal mounting partition is fixed inside the main casing, dividing the internal space of the main casing into a front display space and a rear movement assembly space that are adjacent to each other. The movement base and the main movement are both located in the rear movement assembly space. The central axis extends forward from the rear movement assembly space through the internal mounting partition and into the front display space. The pointer, label, front limiting rigid baffle, and rear limiting elastic baffle are all located in the front display space. A rear sealing end cap that covers the movement base and the main movement is fixed at the rear opening of the main casing. A front sealing visible component located in front of the pointer is fixed at the front opening of the main casing.

[0019] As a preferred embodiment of the present invention, the front-sealed visual assembly includes a tensioning drive ring, a viewing glass plate, and a sealing gasket that abut against each other in sequence. The inner ring of the front opening of the main housing forms an annular stepped groove for inserting the tensioning drive ring, the viewing glass plate, and the sealing gasket. The viewing glass plate is circular. The rear side of the sealing gasket abuts against the rear bottom of the annular stepped groove, while the outer ring abuts against the side wall of the annular stepped groove. The outer ring wall of the tensioning drive ring forms an external thread, and the side wall of the annular stepped groove forms an internal thread, allowing the outer ring wall of the tensioning drive ring to be tightened and loosened by the thread. The inner ring of the tensioning drive ring forms a drive operation reinforcing block that is circumferentially arrayed and spaced apart for driving rotation.

[0020] As a preferred embodiment of the present invention, the main housing, the rear sealing end cover, and the tensioning drive ring are all engineering plastic parts, and a flange connecting plate for assembly with other facilities is integrally formed on the front part of the outer wall of the main housing.

[0021] As a preferred embodiment of the present invention, a reinforced mounting balance panel is fixed to the front side of the movement base. The surface of the inner mounting partition is perpendicular to the axial direction of the main housing and its outer periphery is integrally connected to the inner ring wall of the main housing. The reinforced mounting balance panel is fixed to the rear surface of the inner mounting partition. The central shaft passes forward through the reinforced mounting balance panel, and the reinforced mounting balance panel has an opening for the central shaft to pass through.

[0022] As a preferred embodiment of the present invention, the movement base is fitted with a pressure medium interface component, the pressure medium interface component passes through the rear sealing end cover and extends out of the rear movement assembly space, and a sealing structure is provided between the periphery of the pressure medium interface component and the opening through which the rear sealing end cover is passed.

[0023] As a preferred embodiment of the present invention, the axial elastic locking and limiting mechanism further includes a positioning sleeve located around the central shaft. The center of the nameplate is provided with a front alignment center hole that passes through the positioning sleeve. The positioning sleeve is fixed inside the housing assembly. The front limiting rigid baffle is ring-shaped and fixed at the front position of the positioning sleeve. The central shaft passes axially forward through the inner ring of the front limiting rigid baffle and a pointer located on the front side of the front limiting rigid baffle is fixed at its front end. The rear limiting elastic baffle can extend and retract circumferentially to change the axial elastic force.

[0024] As a preferred embodiment of the present invention, the rear limiting elastic baffle is a semi-closed C-shaped conical spring sheet with a radial dimension that gradually increases from front to back. Both the inner and outer surfaces of the rear limiting elastic baffle are conical and form an opening in the circumferential direction. The rear limiting elastic baffle is sleeved on the outer wall of the positioning sleeve.

[0025] As a preferred embodiment of the present invention, the rear end face of the rear limiting elastic baffle is integrally connected with a semi-enclosed C-shaped reinforcing piece. The radially outward portion of the C-shaped reinforcing piece is embedded in the inner ring of an annular outer peripheral limiting pad. The inner ring of the outer peripheral limiting pad has a circular, radially outwardly recessed outer peripheral embedding limiting groove for the radially outward portion of the C-shaped reinforcing piece to be embedded, so that the C-shaped reinforcing piece can extend and retract circumferentially and be limited in the front and rear directions after being embedded. The front end portion of the rear limiting elastic baffle protrudes from the front side surface of the outer peripheral annular limiting pad and abuts against the rear side of the sign.

[0026] As a preferred embodiment of the present invention, the C-shaped reinforcing plate and the outer peripheral annular limiting pad are both located within the front display space. The rear side of the outer peripheral annular limiting pad abuts against the front side of the inner mounting partition. The positioning sleeve extends forward from the inner mounting partition into the front display space. The inner mounting partition has a rear alignment center hole for the central shaft and the positioning sleeve to pass forward simultaneously. The positioning sleeve is fixed to the inner mounting partition.

[0027] As a preferred embodiment of the present invention, an external thread is formed on the rear part of the outer surface of the positioning sleeve, forming a threaded assembly section. A mounting groove is provided on the rear side surface of the inner mounting partition, which is recessed forward and radially communicates with the rear alignment center hole. A polygonal nut capable of circumferential positioning is inserted into the mounting groove. The threaded assembly section is fixed in the inner ring of the polygonal nut by means of threads.

[0028] As a preferred embodiment of the present invention, a tool relief groove is formed on the outer surface of the positioning sleeve at a position in front of the threaded assembly section, the foremost part of the rear limiting elastic baffle is located in front of the tool relief groove, and a rotating operation hole extending in the front-rear direction is provided on the front limiting rigid baffle for operating the rotating positioning sleeve.

[0029] As a preferred embodiment of the present invention, the non-contact driven component is a magnetic component.

[0030] As a preferred embodiment of the present invention, the non-contact driven component includes a magnetic block fixed to the rear side of the sign and located in front of the inner mounting partition.

[0031] As a preferred embodiment of the present invention, the magnetic block is a ring-shaped block with a surface magnetic field strength of not less than 2000 Gauss, and the radial distance between the center of the magnetic block and the center of the sign is 0.6-0.95 times the radius of the sign.

[0032] The beneficial effects of the present invention are: it enables non-contact zeroing: the nameplate is provided with a non-contact driven component, and a driving tool located outside the pressure gauge can be used to apply circumferential driving force to the nameplate, without the need to set a through zeroing hole in the main housing or the visible glass plate, and without the need to directly contact the nameplate.

[0033] Zeroing does not require disassembling the front sealing and visual components: the operator can drive the nameplate through the visible glass plate, avoiding damage to the internal sealing environment of the pressure gauge due to disassembling the loosening and tightening drive ring, the visible glass plate, or the sealing gasket, thus improving the convenience of zeroing operation.

[0034] Balancing rotatability and locking stability: The nameplate is clamped between a front limit rigid baffle and a rear limit elastic baffle. During zeroing, the external driving force overcomes the frictional force to rotate the nameplate; after zeroing, the rear limit elastic baffle continues to press the nameplate firmly, allowing the nameplate to remain stably in the adjusted position by friction.

[0035] The elastic locking force is adjustable: the rear limit elastic baffle adopts a semi-closed C-shaped conical surface structure, which can change the axial height and axial elastic force through its circumferential extension and contraction, which is beneficial to set an appropriate locking force according to the nameplate material, surface friction coefficient and required zeroing torque.

[0036] Compact structure: The positioning sleeve is set on the periphery of the central shaft, and the front limit rigid baffle, the nameplate and the rear limit elastic baffle are arranged in sequence along the axial direction of the central shaft, making full use of the limited space behind the pointer, which is suitable for miniaturized and compact pressure gauges.

[0037] To avoid interfering with the rotation of the central shaft: the nameplate is radially positioned by a positioning sleeve, which is fixed in the housing assembly. The rotation and locking forces of the nameplate are not directly applied to the central shaft, thereby reducing the impact of the nameplate zeroing structure on the movement's measurement actions.

[0038] To improve the structural stability of the rear limit elastic baffle: A C-shaped reinforcing plate is set at the rear end of the rear limit elastic baffle. The C-shaped reinforcing plate is embedded in the outer periphery of the outer ring limit pad and embedded in the limit groove. This can both constrain the rear limit elastic baffle axially and retain its circumferential expansion and contraction capacity.

[0039] The positioning sleeve is reliably assembled: the positioning sleeve is connected to the polygonal nut, which is circumferentially limited, via a threaded assembly section. During assembly, the positioning sleeve can be tightened without separately clamping the nut. The rotating operating hole on the front limiting rigid baffle facilitates the application of rotational torque by the tool.

[0040] The front sealing structure facilitates assembly and maintenance: the tensioning drive ring presses the viewing glass plate and the sealing gasket together by threads, which not only forms a front seal, but also makes it easy to disassemble and replace the viewing glass plate or the sealing gasket when needed.

[0041] The pressure gauge features overall lightweight construction: the main housing, rear sealing end cap, and tensioning drive ring are made of engineering plastics, reducing product weight and manufacturing costs. The flange connection plate on the main housing is integrally molded with the main housing, which helps reduce the number of parts and improves installation efficiency.

[0042] The zeroing torque is large and the drive is stable: the magnetic block is set at a position of 0.6 to 0.95 times the radius of the sign, so that a long lever arm is formed between the magnetic block and the center of the sign. The use of a magnetic block with a surface magnetic field strength of not less than 2000 Gauss is beneficial for reliable drive through the visible glass plate. Attached Figure Description

[0043] Figure 1 This is a three-dimensional structural diagram of the pressure gauge in the embodiment;

[0044] Figure 2 yes Figure 1 A three-dimensional structural diagram of the front sealing visible component in the disassembled state;

[0045] Figure 3 yes Figure 1 A three-dimensional structural diagram from a rear view;

[0046] Figure 4 yes Figure 3 A three-dimensional structural diagram after the rear sealing end cap is removed from the structure;

[0047] Figure 5 yes Figure 1 A schematic diagram of the three-dimensional structure in the later stages of the structural disassembly.

[0048] Figure 6 yes Figure 5 A three-dimensional structural diagram from a rear view;

[0049] Figure 7 yes Figure 6 A three-dimensional structural diagram showing the location of the main shell in the structure;

[0050] Figure 8 yes Figure 7A schematic diagram of the three-dimensional structure after the polygonal nut is removed from the structure;

[0051] Figure 9 yes Figure 1 Left view of the middle structure after the main shell has been removed;

[0052] Figure 10 yes Figure 9 A schematic diagram of the three-dimensional structure from a frontal perspective;

[0053] Figure 11 yes Figure 9 A schematic diagram of the three-dimensional structure from a rearward perspective;

[0054] Figure 12 yes Figure 11 A schematic diagram of the three-dimensional structure after the polygonal nut is removed from the structure;

[0055] Figure 13 yes Figure 12 A three-dimensional structural diagram after the removal of the reinforcing and balancing panel in the structure;

[0056] Figure 14 yes Figure 9 A three-dimensional structural diagram of the part containing the axial elastic locking and limiting mechanism in the structure;

[0057] Figure 15 yes Figure 14 A three-dimensional structural diagram from a rear view;

[0058] Figure 16 yes Figure 14 A three-dimensional structural diagram after the outer annular limiting pad in the structure has been removed;

[0059] Figure 17 yes Figure 16 A three-dimensional structural diagram from a rear view;

[0060] Figure 18 yes Figure 14 A three-dimensional structural diagram of the outer annular limiting pad in the middle;

[0061] Figure 19 yes Figure 14 A three-dimensional structural diagram of the rear limiting elastic baffle and C-shaped reinforcing plate in the middle;

[0062] Figure 20 yes Figure 14 A three-dimensional structural diagram of the positioning sleeve and the front limiting rigid baffle in the middle;

[0063] Figure 21 yes Figure 14 A three-dimensional structural diagram after the pointer connector in the structure has been removed;

[0064] Figure 22yes Figure 21 A three-dimensional structural diagram showing the central structure after the nameplate and polygonal nut have been assembled and the outer annular limiting pad has been removed.

[0065] Figure 23 yes Figure 1 A three-dimensional structural diagram of the main shell in the structure;

[0066] Figure 24 yes Figure 23 A three-dimensional structural diagram from a rear view;

[0067] Figure 25 yes Figure 11 A three-dimensional structural diagram of the time behind the sign in the structure;

[0068] Figure 26 yes Figure 1 A sectional view of the structure after it has been vertically cut along the axis from top to bottom. Detailed Implementation

[0069] The present invention will be further described in detail below with reference to the accompanying drawings.

[0070] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0071] Examples, such as Figure 1-26 As shown, this embodiment provides a compact precision pressure gauge, including a housing assembly and a movement assembly 1 installed inside the housing assembly.

[0072] The outer casing assembly includes a generally cylindrical main casing 4. Both the front and rear ends of the main casing 4 have openings, and an internal mounting partition 40 is disposed inside the main casing 4. Preferably, the surface of the internal mounting partition 40 is perpendicular or substantially perpendicular to the axial direction of the main casing 4, or its outer periphery is preferably integrally formed and connected to the inner wall of the main casing 4; however, other existing fixing methods can also be used for fixing and connection.

[0073] An internal mounting partition 40 divides the internal space of the main housing 4 into a front display space 401 located at the front and a rear movement assembly space 402 located at the rear. The front display space 401 is used to accommodate the pointer 121, the nameplate 2, and the axial elastic locking limit mechanism; the rear movement assembly space 402 is used to accommodate the movement base 11 and the main movement 12.

[0074] The movement assembly 1 includes a movement base 11 and a main movement 12 mounted on the movement base 11. The main movement 12 is fitted with a central shaft 120, which converts the displacement generated by the pressure detection mechanism into rotation of the central shaft 120. The central shaft 120 extends forward from the rear movement assembly space 402, passes sequentially through the reinforced mounting balance panel 112 and the inner mounting partition 40, and enters the front display space 401. The reinforced mounting balance panel 112 is a preferred structure of this embodiment, which will be mentioned later, but it is not required. The movement assembly 1 can use existing components, including the movement base 11 and the main movement 12. The main movement 12 has a central gear and a sector gear that cooperates with the central gear, as well as a hairspring. The central gear is connected to the rear end of the central shaft 120. The sector gear is connected to one end of the Bourdon tube through a connecting rod. The other end of the Bourdon tube is assembled and connected to the movement base 11. The movement base 11 is also assembled and connected to a pressure medium interface component 111. The end of the pressure medium interface component 111 that is assembled with the movement base 11 will connect to the end of the Bourdon tube that is assembled with the movement base 11. This is the conventional movement assembly structure and assembly operation method, which will not be described in detail here.

[0075] A pointer 121 is fixed to the front end of the central shaft 120. When the measured pressure changes, the main core 12 drives the central shaft 120 to rotate, and the central shaft 120 drives the pointer 121 to rotate synchronously. The pointer 121 moves relative to the pressure scale on the label 2 to display the measured pressure value. The pointer's own shaft hole and the central shaft can be directly fixed by interference fit, or the pointer and the central shaft can be fixedly connected by a pointer connector 1210 such as a riveting structure.

[0076] The nameplate 2 is located behind the pointer 121. The nameplate 2 may be disc-shaped, with scale lines, scale values, unit markings, product markings, warning areas, or other pressure display information on its front surface. The nameplate 2 has a through-hole 20 at its center, through which the central shaft 120 and the positioning sleeve 33 (mentioned later) pass.

[0077] A rear sealing end cover 41 is installed at the rear opening of the main housing 4. The rear sealing end cover 41 covers the movement base 11 and the main movement 12, and is used to protect the rear movement assembly space 402.

[0078] A front-sealed viewing assembly is installed at the front opening of the main housing 4. The front-sealed viewing assembly is located in front of the pointer 121, making the front display space 401 a relatively enclosed display area, and allowing the operator to observe the pointer 121 and the label 2 from the front of the pressure gauge.

[0079] A further preferred embodiment of the axial elastic locking and limiting mechanism:

[0080] The nameplate 2 is installed on the periphery of the central shaft 120 via an axial elastic locking limit mechanism.

[0081] The axial elastic locking and limiting mechanism includes a front limiting stop assembly and a rear limiting stop assembly. The front limiting stop assembly and the rear limiting stop assembly are arranged axially at intervals along the central axis 120, and the nameplate 2 is disposed between the two.

[0082] In this embodiment, the front limiting blocking component includes a front limiting rigid baffle 31, and the rear limiting blocking component includes a rear limiting elastic baffle 32.

[0083] The front limiting rigid baffle 31 is generally annular, with an inner ring at its center through which the central shaft 120 passes. The front limiting rigid baffle 31 has a relatively stable axial position and is used to limit the forward movement of the sign 2. The front limiting rigid baffle 31 is preferably made of rigid engineering plastic or a non-magnetic metal structure.

[0084] The rear limiting elastic baffle 32 is located behind the sign 2, and the front end of the rear limiting elastic baffle 32 abuts against the rear side of the sign 2. The rear limiting elastic baffle 32 generates a forward axial elastic force, pressing the sign 2 against the rear side of the front limiting rigid baffle 31.

[0085] Contact areas are formed between the front side of the sign 2 and the front limiting rigid baffle 31, and between the rear side of the sign 2 and the rear limiting elastic baffle 32. Under the action of the axial elastic force of the rear limiting elastic baffle 32, friction is generated in the contact areas.

[0086] Without the action of an external zero-adjustment driving force, the aforementioned frictional force can prevent the nameplate 2 from rotating circumferentially relative to the front limit rigid baffle 31, thereby keeping the nameplate 2 in a locked state.

[0087] During zeroing, an external non-contact driving force acts on the non-contact driven component on the nameplate 2. When the circumferential torque generated by this driving force on the nameplate 2 is greater than the static friction locking torque on the nameplate 2, the nameplate 2 rotates relative to the front limit rigid baffle 31 and the rear limit elastic baffle 32.

[0088] After the sign 2 is rotated to the desired position, the external non-contact driving force is removed, and the sign 2 remains in the adjusted position under the action of axial clamping force and friction. Thus, the rotation adjustment and automatic locking of the sign 2 can be achieved without the need for additional complex mechanical locking mechanisms.

[0089] Further preferred embodiments of the positioning sleeve structure:

[0090] The axial elastic locking and limiting mechanism also includes a positioning sleeve 33. The positioning sleeve 33 is disposed around the central shaft 120, and the central shaft 120 passes axially through the inside of the positioning sleeve 33, and of course, it also passes through the front alignment center hole 20.

[0091] The outer wall of the positioning sleeve 33 passes through the front alignment center hole 20 at the center of the nameplate 2. A fitting clearance is provided between the front alignment center hole 20 and the positioning sleeve 33 to allow the nameplate 2 to rotate, so that the positioning sleeve 33 can radially position the nameplate 2, but will not rigidly fix the nameplate 2 to the positioning sleeve 33.

[0092] The front limiting rigid baffle 31 is fixed at the front position of the positioning sleeve 33. The front limiting rigid baffle 31 and the positioning sleeve 33 can be made of the same material and integrally formed and fixed, or they can be connected by welding, bonding, interference fit or other fixing methods. In this embodiment, the main purpose is to form a fixed structure in which the front limiting rigid baffle 31 and the positioning sleeve 33 can rotate together.

[0093] The central shaft 120 passes forward through the inner ring of the front limiting rigid baffle 31. The pointer 121 is fixed at the front end of the central shaft 120 and located in front of the front limiting rigid baffle 31. Rotational clearances are maintained between the central shaft 120 and the interior of the positioning sleeve 33, and between the central shaft 120 and the inner ring of the front limiting rigid baffle 31, allowing the central shaft 120 to rotate normally relative to the stationary positioning sleeve 33 and the front limiting rigid baffle 31. Clearly, the inner ring of the front limiting rigid baffle 31 and the interior of the positioning sleeve 33 are connected.

[0094] Since the nameplate 2 is positioned by the positioning sleeve 33, and the positioning sleeve 33 is fixed on the outer shell assembly, the axial clamping force on the nameplate 2 is mainly borne by the positioning sleeve 33, the inner mounting partition 40 and related limiting parts, and is not directly transmitted to the central shaft 120, which helps to avoid increasing the rotational resistance of the central shaft 120.

[0095] A further preferred embodiment of the rear limiting elastic baffle structure:

[0096] The rear limiting elastic baffle 32 is a semi-enclosed C-shaped conical spring. The rear limiting elastic baffle 32 is arranged around the periphery of the positioning sleeve 33, and its radial dimension gradually increases from front to back.

[0097] The inner and outer surfaces of the rear limiting elastic baffle 32 are both conical, forming a truncated cone-shaped elastic structure. The rear limiting elastic baffle 32 has an opening in the circumferential direction, thus forming a semi-closed C-shaped structure.

[0098] When the rear limiting elastic baffle 32 is subjected to axial compression, the inclination of its conical surface changes, and it can simultaneously expand or contract circumferentially through the circumferential opening. This structure can provide a relatively stable axial elastic force within a small axial installation space.

[0099] The front end of the rear limiting elastic baffle 32 abuts against the rear side of the sign 2. This front end can form a relatively smooth contact edge to reduce scratches on the rear side of the sign 2 and to apply the elastic force more evenly along the circumference to the sign 2.

[0100] The rear limiting elastic baffle 32 is sleeved on the outer wall of the positioning sleeve 33, which can limit excessive radial displacement of the rear limiting elastic baffle 32. The circumferential opening of the rear limiting elastic baffle 32 not only facilitates its side or axial assembly to the periphery of the positioning sleeve 33, but more importantly, under axial pressure, the elastic force can be effectively changed by the expansion and contraction of the opening. Similar to the principle of a spring, the tighter it is compressed, the greater the elastic force will be.

[0101] The rear limit elastic stop 32 can be made of spring steel, stainless steel elastic sheet, or other materials with appropriate elasticity and fatigue resistance. Its thickness, taper, opening width, and radial dimensions can be set according to the locking torque required by the nameplate 2.

[0102] Further preferred methods for the C-type reinforcing plate and the outer circumferential limiting pad:

[0103] The rear end face of the rear limiting elastic baffle 32 is integrally connected with a C-shaped reinforcing plate 321. The C-shaped reinforcing plate 321 is also a semi-closed structure, and has an opening in the circumferential direction to adapt to elastic deformation.

[0104] The C-shaped reinforcing piece 321 is used to enhance the structural strength of the rear end portion of the rear limiting elastic baffle 32 and to distribute the supporting force on the rear limiting elastic baffle 32 more evenly along the circumferential direction. The surface of the C-shaped reinforcing piece 321 is preferably perpendicular or substantially perpendicular to the axial direction.

[0105] The radially outer portion of the C-shaped reinforcing piece 321 is embedded into the inner ring of an outer annular limiting pad 34. The outer annular limiting pad 34 is generally circular, and its inner ring portion forms an outer peripheral embedding limiting groove 340. The outer annular limiting pad 34 is preferably made of rigid engineering plastic or a non-magnetic metal structure.

[0106] The outer peripheral embedded limiting groove 340 is a circular groove extending in the circumferential direction and is radially recessed outward relative to the inner ring surface of the outer peripheral annular limiting pad 34. The outer peripheral portion of the C-shaped reinforcing piece 321 extends into the outer peripheral embedded limiting groove 340.

[0107] The front and rear groove walls of the peripheral embedded limiting groove 340 can limit the C-shaped reinforcing piece 321 in the front and rear, preventing the C-shaped reinforcing piece 321 from axially dislodging from the peripheral annular limiting pad 34. At the same time, the peripheral embedded limiting groove 340 retains space for the C-shaped reinforcing piece 321 to expand and contract in the circumferential direction, and will not hinder the elastic deformation of the rear limiting elastic baffle 32.

[0108] The front end of the rear limiting elastic baffle 32 protrudes from the front side of the outer peripheral annular limiting pad 34. Therefore, when the rear side of the outer peripheral annular limiting pad 34 is supported by the inner mounting partition 40, the rear limiting elastic baffle 32 can still press against and tighten the nameplate 2.

[0109] The rear side of the outer annular limiting pad 34 abuts against the front side of the inner mounting partition 40. The inner mounting partition 40 thus provides axial support for the outer annular limiting pad 34 and transmits axial elastic force to the nameplate 2 via the C-shaped reinforcing plate 321 and the rear limiting elastic baffle 32.

[0110] Further preferred methods for the assembly structure of the positioning sleeve and the inner mounting plate:

[0111] The inner mounting plate 40 has a rear alignment center hole 400. The central shaft 120 and the positioning sleeve 33 pass forward through the rear alignment center hole 400 at the same time.

[0112] The locating sleeve 33 has an external thread on its rear outer surface, forming a threaded assembly section 331. The rear surface of the inner mounting partition 40 has a forward-recessed mounting groove 4001. The mounting groove 4001 is radially connected to the rear alignment center hole 400.

[0113] A polygonal nut 4002 is embedded in the mounting groove 4001. The polygonal nut 4002 can be a hexagonal nut, a quadrilateral nut, or other non-circular nuts. The inner wall shape of the mounting groove 4001 is adapted to the outer contour of the polygonal nut 4002, thereby circumferentially limiting the polygonal nut 4002.

[0114] The threaded assembly section 331 of the positioning sleeve 33 is screwed into the inner thread of the polygonal nut 4002. Since the polygonal nut 4002 cannot rotate freely within the mounting groove 4001, rotating the positioning sleeve 33 will cause the positioning sleeve 33 to move axially relative to the polygonal nut 4002 and gradually lock it in place.

[0115] The front limiting rigid baffle 31 has a rotating operating hole 333 extending in the front-rear direction. An assembly tool can be inserted into the rotating operating hole 333 to apply a circumferential force to the front limiting rigid baffle 31, thereby rotating the positioning sleeve 33. Of course, the rotating operating hole 333 can also be used for alignment. Rotation can also be performed by operating the outer circumference of the front limiting rigid baffle 31, although this is relatively inconvenient and the surface is more prone to wear, but it is still possible to implement this method.

[0116] After the positioning sleeve 33 is tightened, the front limiting rigid baffle 31, the nameplate 2, the rear limiting elastic baffle 32, the C-shaped reinforcing plate 321, the outer peripheral annular limiting pad 34 and the inner mounting partition 40 can form a mutually cooperating axial structure.

[0117] The positioning sleeve 33 has a relief groove 332 on its outer surface located in front of the threaded assembly section 331. The relief groove 332 serves as a relief space when machining the threaded assembly section 331 and prevents the thread end from interfering with adjacent components. The foremost part of the rear limiting elastic baffle 32 is located in front of the relief groove 332, thereby ensuring that the rear limiting elastic baffle 32 can stably abut against the nameplate 2.

[0118] During assembly, the axial fit of related parts can be adjusted by controlling the depth to which the positioning sleeve 33 is screwed into the polygonal nut 4002. However, the specific position of the positioning sleeve 33 after tightening should ensure that the nameplate 2 can rotate under a predetermined external driving force and reliably lock after the external driving force disappears.

[0119] Further implementation methods for the non-contact magnetic zeroing structure:

[0120] The sign 2 is equipped with a non-contact driven component. In this embodiment, the non-contact driven component is a magnetic component, specifically including a magnetic block 5 fixed to the rear side of the sign 2.

[0121] The magnetic block 5 is located in front of the inner mounting partition 40 and is set together with the sign 2 in the front display space 401. The magnetic block 5 is fixedly connected to the sign 2, so that the circumferential driving force on the magnetic block 5 can be transmitted to the sign 2.

[0122] The magnetic block 5 can be fixed to the rear side of the sign 2 by adhesive, embedding, snap-fit ​​or other means. In order to maintain the integrity of the front display surface of the sign 2, the magnetic block 5 is preferably placed on the rear side of the sign 2 so that it does not obstruct the scale and text on the front side of the sign 2.

[0123] In this embodiment, the magnetic block 5 is in the shape of a ring. The surface magnetic field strength of the magnetic block 5 is not less than 2000 Gauss to ensure that it can form sufficient magnetic interaction force with the external magnetic driving tool through the visible glass plate 423.

[0124] The center of magnetic block 5 is offset relative to the center of sign 2. The radial distance between the center of magnetic block 5 and the center of sign 2 is 0.6 to 0.95 times the radius of sign 2. Thus, magnetic block 5 is located on the outer periphery of the center of sign 2.

[0125] Assuming the tangential driving force on magnetic block 5 is F, and the radial distance between the center of magnetic block 5 and the center of sign 2 is L, then the torque generated by magnetic block 5 on sign 2 is approximately related to the product of F and L. By increasing L, a larger zero-adjustment torque can be obtained under the same magnetic force conditions.

[0126] During zeroing, bring the external magnetic drive tool close to the visible glass plate 423 and align it with the position of the magnetic block 5. Then move the external magnetic drive tool along the circumference of the label 2, and the magnetic block 5 will move circumferentially under the magnetic force of the magnetic drive tool.

[0127] When the torque generated by the magnetic driving force is greater than the frictional locking torque on the nameplate 2, the magnetic block 5 drives the nameplate 2 to rotate around the positioning sleeve 33. The operator observes the positional relationship between the pointer 121 and the zero mark on the nameplate 2 until the zero mark rotates to the position corresponding to the pointer 121 in the no-pressure state.

[0128] After zeroing is completed, remove the external magnetic drive tool. At this time, the magnetic block 5 is no longer subjected to an external force sufficient to drive the nameplate 2 to rotate, and the nameplate 2 remains in the adjusted position under the pressing action of the rear limit elastic baffle 32.

[0129] The external magnetic drive tool does not necessarily have to be part of the pressure gauge body. It can be a permanent magnet or an electromagnetic drive device that generates a magnetic field when energized. The magnetic field strength and shape of the external magnetic drive tool can be set according to the thickness of the visible glass plate 423, the position of the magnet 5, and the locking torque of the nameplate 2.

[0130] Further preferred methods for the front-sealed visual assembly:

[0131] An annular stepped groove 44 is formed on the inner ring of the opening on the front side of the main housing 4. The annular stepped groove 44 is used to accommodate the tensioning drive ring 421, the viewing glass plate 423 and the sealing gasket 422.

[0132] The tensioning drive ring 421, the visible glass plate 423, and the sealing gasket 422 abut against each other from front to back. The visible glass plate 423 is circular and can be made of transparent glass, transparent engineering plastic, or other visible materials with appropriate transparency and structural strength.

[0133] The sealing gasket 422 is located on the rear side of the viewing glass plate 423. The rear side of the sealing gasket 422 abuts against the rear bottom of the annular stepped groove 44, and its outer ring abuts against the side wall of the annular stepped groove 44. The sealing gasket 422 can produce appropriate elastic deformation when subjected to axial compression to seal the gap between the viewing glass plate 423 and the main housing 4.

[0134] The outer wall of the tensioning drive ring 421 is provided with external threads, and the side wall of the annular stepped groove 44 is provided with matching internal threads. The tensioning drive ring 421 is screwed into the annular stepped groove 44 through the threads.

[0135] When the tightening drive ring 421 is rotated in the tightening direction, the tightening drive ring 421 moves axially backward and presses the viewing glass plate 423 and the sealing gasket 422 in sequence. After being compressed, the sealing gasket 422 comes into close contact with the viewing glass plate 423 and the annular stepped groove 44, thereby forming a front-end seal.

[0136] When the tensioning drive ring 421 is rotated in the loosening direction, the tensioning drive ring 421 moves forward along the axial direction, and the clamping force on the visible glass plate 423 and the sealing gasket 422 is reduced, making it easier to disassemble, inspect or replace them.

[0137] The inner ring of the tensioning drive ring 421 is provided with multiple drive operation reinforcing blocks 4211. The multiple drive operation reinforcing blocks 4211 are distributed at intervals along the circumference and form a structure for applying force to the tool. After the corresponding tool cooperates with the drive operation reinforcing block 4211, the tensioning drive ring 421 can be rotated easily.

[0138] The drive operation reinforcement block 4211 can also enhance the radial strength of the inner ring of the tension drive ring 421, reducing the possibility of deformation of the tension drive ring 421 under the action of tool force or thread locking force.

[0139] Since the zeroing operation can be completed through the magnetic force across the viewing glass plate 423, there is no need to loosen the tension drive ring 421 during normal zeroing, and the front sealing viewing component can always remain sealed.

[0140] Further optimization of the movement assembly mounting structure:

[0141] A reinforced mounting balance panel 112 is fixed to the front side of the movement base 11. The reinforced mounting balance panel 112 is fixed to the rear surface of the inner mounting partition 40.

[0142] The reinforced mounting balance panel 112 has an opening for the central shaft 120 to pass through. The opening size is larger than the central shaft 120 so as not to affect the rotation of the central shaft 120. After the central shaft 120 passes forward through the reinforced mounting balance panel 112, it passes through the rear alignment center hole 400 on the inner mounting partition 40 and enters the front display space 401. At the same time, it also passes through the inside of the positioning sleeve 33 and the front alignment center hole 20 on the nameplate, and fixes the pointer 121 at the front end.

[0143] Strengthening the mounting balance panel 112 can increase the support area between the movement assembly 1 and the inner mounting partition 40, reduce the tilt caused by uneven local stress on the movement base 11, and improve the coaxiality between the central shaft 120 and the rear alignment center hole 400.

[0144] The reinforced mounting balance panel 112 can be fixed to the rear side of the inner mounting partition 40 by screws, snap-fit ​​structures, adhesive structures, or other connection methods. The movement base 11 can be fixed to the reinforced mounting balance panel 112, or the movement base 11 and the reinforced mounting balance panel 112 can be pre-connected and then installed as a whole onto the inner mounting partition 40. The reinforced mounting balance panel 112 is an isosceles triangle or an approximately isosceles triangle.

[0145] The main drive mechanism 12 is mounted on the mechanism base 11. The specific transmission method of the main drive mechanism 12 can be selected according to the measurement principle of the pressure gauge, as long as it can respond to the measured pressure and drive the central shaft 120 to rotate, that is, the existing implementation method mentioned above is acceptable.

[0146] Further optimization of the pressure medium interface and rear sealing structure:

[0147] The movement base 11 is fitted with a pressure medium interface component 111. The pressure medium interface component 111 extends rearward through the rear sealing end cover 41 and protrudes from the rear movement assembly assembly space 402.

[0148] The pressure medium interface component 111 is used to connect to the pressure pipeline, pressure vessel, fluid equipment, or other pressure source to be tested. The pressure medium interface component 111 may be provided with external threads, internal threads, plug-in structure, snap-fit ​​structure, or other pressure interface structure.

[0149] The rear sealing end cap 41 has an opening through which the pressure medium interface component 111 passes. A sealing structure is provided between the periphery of the pressure medium interface component 111 and the opening. The sealing structure may include a sealing ring, a sealing sleeve, a sealing adhesive layer, or a mating sealing step.

[0150] This sealing structure reduces the amount of dust, moisture, or other external impurities that can enter the rear mechanism assembly space 402 through the gap between the pressure medium interface component 111 and the rear sealing end cap 41.

[0151] The rear sealing end cap 41 can be made of working plastic and formed into a circular structure, and can be fixed to the rear opening of the main housing 4 by snap-fit, threaded connection, fastener connection, adhesive bonding or welding. When it is necessary to improve the sealing performance of the rear end, a sealing ring or sealing adhesive layer can also be provided between the rear sealing end cap 41 and the main housing 4.

[0152] Further implementation methods for the engineering plastic housing and mounting flange:

[0153] In this embodiment, the main housing 4, the rear sealing end cap 41, and the tensioning drive ring 421 are all made of engineering plastics. Engineering plastics can be selected based on the usage environment, using materials with appropriate mechanical strength, dimensional stability, heat resistance, corrosion resistance, and aging resistance.

[0154] Using engineering plastics can reduce the overall weight of the pressure gauge and facilitate the formation of an integrated structure for the main housing 4, including the internal mounting partition 40, the annular stepped groove 44, and the flange connection plate 444.

[0155] The front part of the outer wall of the main housing 4 has an integrally formed flange connection plate 444. The flange connection plate 444 may be provided with mounting holes, positioning holes, snap-fit ​​parts or other mounting structures for mounting the pressure gauge to the instrument panel, equipment housing or other facilities.

[0156] The flange connection plate 444 is located near the front of the main housing 4, which helps to expose the front display area of ​​the pressure gauge to the installation facility. The rear movement assembly 1 and the pressure medium interface component 111 are located inside the installation facility, thus forming an embedded installation structure.

[0157] Assembly process:

[0158] One assembly process of the pressure gauge of the present invention is as follows:

[0159] 1. Place the polygonal nut 4002 into the mounting groove 4001 on the rear side of the inner mounting partition 40, so that the polygonal nut 4002 is circumferentially limited by the mounting groove 4001.

[0160] 2. Install the outer circumferential limiting pad 34 on the front side of the inner mounting partition 40, so that its rear side abuts against the front side of the inner mounting partition 40.

[0161] 3. Insert the outer periphery of the C-shaped reinforcing piece 321 into the outer periphery of the outer annular limiting pad 34 embedded in the limiting groove 340, so that the C-shaped reinforcing piece 321 is limited in the front and rear directions, while retaining the ability to expand and contract in the circumferential direction.

[0162] 4. The rear limit elastic baffle 32 is fitted around the positioning sleeve 33, with its front end facing the nameplate 2.

[0163] 5. Fit the nameplate 2 through the front alignment center hole 20 to the outer periphery of the positioning sleeve 33, and position the nameplate 2 between the front limiting rigid baffle 31 and the rear limiting elastic baffle 32.

[0164] 6. Pass the threaded assembly section 331 of the positioning sleeve 33 through the rear alignment center hole 400 of the inner mounting partition 40, and screw in the polygonal nut 4002.

[0165] 7. Using a tool, insert the rotating operating hole 333 on the front limit rigid baffle 31, rotate the positioning sleeve 33 to lock the positioning sleeve 33 with the polygonal nut 4002, and subject the nameplate 2 to appropriate axial elastic clamping force.

[0166] 8. Install the movement base 11, main movement 12 and reinforced mounting balance panel 112 on the rear side of the inner mounting partition 40, so that the central shaft 120 passes through the reinforced mounting balance panel 112, the rear alignment center hole 400, the front alignment center hole 20, the positioning sleeve 33 and the inner ring of the front limit rigid baffle 31 in sequence.

[0167] 9. Install pointer 121 at the front end of central shaft 120, so that pointer 121 is located in front of sign 2 and front limit rigid baffle 31.

[0168] 10. Pass the pressure medium interface component 111 through the rear sealing end cover 41, and set a sealing structure between the two. Then fix the rear sealing end cover 41 to the opening on the rear side of the main housing 4.

[0169] 11. Sequentially install the sealing gasket 422 and the viewing glass plate 423 into the annular stepped groove 44 on the front side of the main housing 4, and then screw the tensioning drive ring 421 into the annular stepped groove 44.

[0170] 12. By driving the reinforcing block 4211 to rotate the tensioning drive ring 421, the tensioning drive ring 421 presses the visible glass plate 423 and the sealing gasket 422 to complete the front-end sealing.

[0171] Pressure measurement process:

[0172] After the pressure gauge is installed on the device under test, the pressure medium to be measured enters the pressure detection section through the pressure medium interface component 111. The pressure-sensitive element deforms under pressure, and the main core 12 converts and amplifies the deformation of the pressure-sensitive element into the rotation of the central shaft 120.

[0173] The central shaft 120 drives the pointer 121 to rotate in front of the label 2. The user can obtain the corresponding pressure reading by observing the position of the pointer 121 relative to the scale of the label 2 through the viewing glass plate 423.

[0174] During the above measurement process, the nameplate 2 is kept fixed by the axial clamping action of the front limiting rigid baffle 31 and the rear limiting elastic baffle 32, and does not rotate with the central axis 120 and the pointer 121.

[0175] Zeroing process:

[0176] One zeroing process for the pressure gauge of this invention is as follows:

[0177] 1. Ensure that the pressure medium interface component 111 is in the specified zero pressure state, or that the pressure gauge is in the corresponding standard calibration state.

[0178] 2. Observe whether there is a positional deviation between pointer 121 and the zero mark on label 2.

[0179] 3. If there is a deviation, bring the external magnetic drive tool close to the position on the visible glass plate 423 corresponding to the magnetic block 5.

[0180] 4. Slowly move the external magnetic drive tool along the circumference of the nameplate 2. The external magnetic drive tool drives the magnetic block 5 through magnetic force, and the magnetic block 5 causes the nameplate 2 to rotate around the positioning sleeve 33.

[0181] 5. Observe the pointer 121 and the zero mark on the label 2 until they reach the specified correspondence.

[0182] 6. Remove the external magnetic drive tool. The rear limit elastic baffle 32 continues to press the nameplate 2 against the front limit rigid baffle 31, keeping the nameplate 2 in the adjusted position.

[0183] The entire zeroing process does not require opening the rear sealing end cover 41, nor does it require disassembling the tightening drive ring 421, the viewing glass plate 423, or the sealing gasket 422, thus reducing the impact of the zeroing operation on the pressure gauge's sealing performance.

[0184] Locking force adjustment process:

[0185] If the frictional locking force on the nameplate 2 is too large, the external magnetic drive 6 will have difficulty driving the nameplate 2 to rotate. In the assembled or maintenance state, a tool can be used to rotate the operating hole 333 to make the positioning sleeve 33 rotate in the direction of reducing the clamping force.

[0186] If the frictional locking force on the nameplate 2 is too small, it is easy for it to rotate on its own under vibration. This can cause the positioning sleeve 33 to rotate in the direction of increasing the clamping force.

[0187] After the axial position of the positioning sleeve 33 changes, the axial distance between the front limiting rigid baffle 31 and the rear limiting elastic baffle 32 changes accordingly, thereby changing the elastic deformation of the rear limiting elastic baffle 32 and the axial pressure on the nameplate 2.

[0188] After the locking force is adjusted, the sign 2 can be subjected to rotational torque test and vibration test to confirm that the sign 2 can rotate under the predetermined external magnetic force and can be reliably locked under normal use.

[0189] Other optional implementation methods:

[0190] Without departing from the basic technical concept of this invention, the following modifications can also be adopted:

[0191] 1. The front limit stop assembly can be an elastic assembly, and the rear limit stop assembly can be a rigid assembly;

[0192] 2. Both the front and rear limit stop components can be axially elastic components;

[0193] 3. In addition to C-type conical spring plates, the rear limit elastic baffle 32 can also be a disc spring, wave spring, annular elastic washer or other structure that can generate axial elastic force;

[0194] 4. The front limit rigid baffle 31 can be integrally formed with the positioning sleeve 33, or it can be fixed on the positioning sleeve 33 as an independent part;

[0195] 5. Wear-resistant pads or friction pads may be installed between the sign 2 and the front limit rigid baffle 31 or between the sign 2 and the rear limit elastic baffle 32;

[0196] 6. There can be one or more magnetic blocks 5, and the multiple magnetic blocks 5 can be spaced apart or asymmetrically arranged along the circumference of the sign 2;

[0197] 7. In addition to ring-shaped blocks, magnetic blocks 5 can also be arc-shaped, cylindrical, square, or other shapes suitable for forming circumferential driving torque;

[0198] 8. The external magnetic drive component 6 can be a permanent magnet or an electromagnetic drive device that generates a magnetic field when energized;

[0199] 9. The visible glass panel 423 can be made of transparent glass or transparent engineering plastic sheet;

[0200] 10. The main housing 4 can be made of engineering plastics, or it can be made of non-magnetic metals or composite materials that will not significantly affect the transmission of magnetic force;

[0201] 11. The rear sealing end cap 41 can be connected to the main housing 4 by means of threads, snaps, fasteners, welding or bonding;

[0202] 12. The shape, number of mounting holes, and position of mounting holes of flange connection plate 444 can be adjusted according to the installation requirements of external equipment.

[0203] All the above variations that still employ the basic technical concepts of rotatable signs, axial elastic locking, and non-contact drive sign zeroing should fall within the protection scope of this invention.

[0204] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A compact precision pressure gauge, comprising a housing assembly and a movement assembly mounted on the housing assembly, the movement assembly comprising a movement base (11) and a main movement (12) mounted on the movement base (11), wherein a connecting central shaft (120) is mounted on the main movement (12), characterized in that, A pointer (121) is fixed at the front end of the central shaft (120). A label (2) located behind the pointer (121) is provided on the periphery of the central shaft (120) and can be rotated to zero and locked. The label (2) is installed on the periphery of the central shaft (120) through an axial elastic locking limit mechanism. A non-contact driven component is provided on the label (2) for rotating to zero by non-contact drive.

2. The compact precision pressure gauge according to claim 1, characterized in that, The axial elastic locking and limiting mechanism includes a front limiting blocking component and a rear limiting blocking component located around the central shaft (120) and arranged at intervals in the axial direction of the central shaft (120), wherein at least one of the front limiting blocking component and the rear limiting blocking component is an axially elastic component.

3. A compact precision pressure gauge according to claim 2, characterized in that, The front limiting blocking assembly includes a front limiting rigid baffle (31), and the rear limiting blocking assembly includes a rear limiting elastic baffle (32). The rear limiting elastic baffle (32) can have an elastic force in the axial direction, and the sign (2) is sandwiched between the front limiting rigid baffle (31) and the rear limiting elastic baffle (32).

4. A compact precision pressure gauge according to claim 3, characterized in that, The outer casing assembly includes a main casing (4) with openings at both the front and back. An internal mounting partition (40) is fixed inside the main casing (4) and divides the internal space of the main casing (4) into a front display space (401) and a rear movement assembly space (402) that are adjacent to each other. The movement base (11) and the main movement (12) are both located in the rear movement assembly space (402). The central shaft (120) passes forward from the rear movement assembly space (402) through the internal mounting partition (401). 40) and extends into the front display space (401). The pointer (121), the sign (2), the front limiting rigid baffle (31) and the rear limiting elastic baffle (32) are all located in the front display space (401). The rear opening of the main housing (4) is fixed with a rear sealing end cap (41) that covers the movement base (11) and the main movement (12) on the rear side. The front opening of the main housing (4) is fixed with a front sealing visible component located in front of the pointer (121).

5. A compact precision pressure gauge according to claim 3 or 4, characterized in that, The axial elastic locking and limiting mechanism also includes a positioning sleeve (33) located around the central shaft (120). The nameplate (2) has a front alignment center hole (20) that runs through the front and back for the positioning sleeve (33) to pass through. The positioning sleeve (33) is fixed inside the housing assembly. The front limiting rigid baffle (31) is ring-shaped and fixed at the front position of the positioning sleeve (33). The central shaft (120) passes through the inner ring of the front limiting rigid baffle (31) axially forward and a pointer (121) located in front of the front limiting rigid baffle (31) is fixed at its front end. The rear limiting elastic baffle (32) can extend and retract in the circumferential direction to change the axial elastic force.

6. A compact precision pressure gauge according to claim 5, characterized in that, The rear limiting elastic baffle (32) is a semi-closed C-shaped conical spring sheet with a radial dimension that gradually increases from front to back. The inner and outer surfaces of the rear limiting elastic baffle (32) are both conical and form an opening in the circumferential direction. The rear limiting elastic baffle (32) is sleeved on the outer wall of the positioning sleeve (33).

7. A compact precision pressure gauge according to claim 6, characterized in that, The rear end face of the rear limiting elastic baffle (32) is integrally connected with a semi-enclosed C-shaped reinforcing piece (321). The radially outward part of the C-shaped reinforcing piece (321) is embedded in the inner ring of an annular outer peripheral limiting pad (34). The inner ring of the outer peripheral limiting pad (34) has a circular outer peripheral embedding limiting groove (340) for the radially outward part of the C-shaped reinforcing piece (321) to be embedded, so that the C-shaped reinforcing piece (321) can be extended and retracted in the circumferential direction and limited in the front and rear directions after being embedded. The front end of the rear limiting elastic baffle (32) protrudes from the front side of the outer peripheral annular limiting pad (34) and is used to abut against the rear side of the nameplate (2).

8. A compact precision pressure gauge according to claim 7, characterized in that, The C-shaped reinforcing plate (321) and the outer peripheral annular limiting pad (34) are also located in the front display space (401). The rear side of the outer peripheral annular limiting pad (34) abuts against the front side of the inner mounting partition (40). The positioning sleeve (33) passes forward from the inner mounting partition (40) into the front display space (401). The inner mounting partition (40) has a rear alignment center hole (400) for the central shaft (120) and the positioning sleeve (33) to pass forward simultaneously. The positioning sleeve (33) is fixed on the inner mounting partition (40).

9. A compact precision pressure gauge according to claim 8, characterized in that, The outer surface of the positioning sleeve (33) has an external thread and a threaded assembly section (331) formed on the rear part. The rear side surface of the inner mounting partition (40) has a forward recessed mounting groove (4001) that is radially connected to the rear alignment center hole (400). A polygonal nut (4002) that can be circumferentially limited is inserted into the mounting groove (4001). The threaded assembly section (331) is fixed in the inner ring of the polygonal nut (4002) by means of threads.

10. A compact precision pressure gauge according to claim 3 or 4, characterized in that, The non-contact driven component is a magnetic component.

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