A high-precision hydraulic measuring mechanical instrument

Abstract

This invention provides a high-precision hydraulic measuring mechanical instrument, comprising a housing, a dial on the front of the housing, a first pointer and a second pointer on the front of the dial, a reduction gear set inside the dial, and the first and second pointers mounted on the rotating shaft of the reduction gear set, with the number of rotations of the first and second pointers proportional. A pressure tube is inserted and fixedly connected to the side wall of the housing. The pressure tube includes a tube body, inside which are a large chamber and a small chamber, both cylindrical chambers. A first piston and a second piston are respectively disposed inside the large and small chambers. A rack is disposed at one end of the second piston, and a spring is sleeved on the outside of the rack, with one end of the spring abutting against the second piston. One end of the rack extends out of the tube body and meshes with the input end of the reduction gear set. This invention improves measurement accuracy by increasing the range.

Description

Technical Field

[0001] This invention relates to the field of pressure gauge technology, and in particular to a high-precision hydraulic measuring mechanical gauge. Background Technology

[0002] A pressure gauge is an instrument that uses an elastic element as its sensing element to measure and indicate pressures higher than ambient pressure. It is extremely widely used, found in almost all industrial processes and scientific research fields. It is ubiquitous in areas such as heat pipe networks, oil and gas transmission, water and gas supply systems, and vehicle repair and maintenance shops.

[0003] Existing mechanical pressure gauges typically use a Bourdon tube as their internal elastic element. When the fluid being measured enters the Bourdon tube, it deforms with changes in pressure. However, the degree of deformation is relatively small, resulting in relatively low reading accuracy. Furthermore, if the fluid entering the Bourdon tube has any negative impact (corrosion / impurities), it can actually affect the measurement accuracy. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a high-precision hydraulic measuring mechanical instrument, comprising a housing, a dial on the front of the housing, a first pointer and a second pointer on the front of the dial, a reduction gear set inside the dial, and the first and second pointers mounted on the shaft of the reduction gear set, with the rotation numbers of the first and second pointers proportional. This design allows the second pointer to rotate one division for every one revolution of the first pointer. The second pointer has multiple divisions, increasing the range and refining the reading, thereby improving the accuracy of the reading.

[0005] A pressure tube is fixedly connected to the side wall of the outer casing. The pressure tube includes a tube body, inside which are a large chamber and a small chamber, both of which are cylindrical. A first piston and a second piston are respectively installed inside the large and small chambers. A rack is installed at one end of the second piston, and a spring is sleeved on the outside of the rack, with one end of the spring abutting against the second piston. One end of the rack extends out of the tube body and meshes with the input end of a reduction gear set. The first and second pistons have different cross-sectional areas, with the second piston having a smaller cross-sectional area. When the fluid pressure is the same, the formula P=kL / S, where P is the pressure, k is the spring constant, L is the distance the piston moves, and S is the cross-sectional area of ​​the piston, is used. The smaller the cross-sectional area of ​​the piston, the greater the distance the piston moves at that point. Therefore, under the action of the first and second pistons, the second piston moves a greater distance, thereby improving the measurement sensitivity and accuracy.

[0006] Preferably, the reduction gear set includes an end gear, a first double gear, an intermediate gear, and a second double gear. The small end of the second double gear meshes with a rack, and the large end of the second double gear meshes with the intermediate gear. The intermediate gear meshes with the small end of the first double gear, and the large end of the first double gear meshes with the end gear. The first pointer is fixed to the shaft of the end gear, and the second pointer is fixedly connected to the shaft of the first double gear. Through the transmission of the reduction gear set, the second pointer rotates one notch for every one revolution of the first pointer.

[0007] Preferably, the large chamber is internally threaded with a first stop, and the small chamber is internally threaded with a second stop. Both the first and second stops have hexagonal through holes in their center. The first and second stops confine the first piston and the second piston to the large and small chambers, respectively.

[0008] Preferably, an adjusting cap is threaded to the upper end of the tube, and one end of the spring abuts against the inner wall of the adjusting cap. The adjusting cap is used for calibration. During production, pressure is pumped in from the lower end of the tube. The pressure is checked against a preset rack extension length. If the pressure does not match the preset rack extension length, the spring preload is controlled by rotating the adjusting cap.

[0009] Preferably, a first pad and a second pad are inserted through the tube body, and the first pad and the second pad are respectively located on the outer and inner sides of the outer shell, fitting snugly against the arc surface of the outer shell. A fixing nut is threaded onto the tube body, and the fixing nut presses against the second pad. With the help of the fixing nut and the first and second pads, the tube body is installed on the outer shell.

[0010] Preferably, the lower sidewall of the pipe body is provided with a threaded section, and the lower sidewall of the pipe body is provided with a regular hexagonal retaining segment. The threaded section is connected to the pipe being tested.

[0011] Preferably, a cover plate is provided on the front of the outer casing, and a retaining ring is provided on the edge of the cover plate, the retaining ring being fixedly connected to the outer casing. The cover plate is fixedly connected to the outer casing by the retaining ring, and sealing rings are provided on both the inner and outer sides of the retaining ring to ensure the pressure gauge's sealing performance.

[0012] The beneficial effects of this invention are as follows: 1. It is equipped with a large chamber, a small chamber, a first piston, a second piston, etc. By amplifying the stroke of the second piston and using a reduction gear set, the rotation angle of the first and second pointers is further amplified, that is, the range is increased, making the reading more refined, thereby improving the measurement accuracy.

[0013] 2. It is equipped with a large chamber, a small chamber, a first piston, a second piston and other structures, which realizes multiple seals, thereby ensuring that the fluid being measured enters the interior of the shell. Compared with the Bourdon tube, the risk of leakage of the fluid being measured is small.

[0014] 3. An adjusting cap is provided for zeroing during the manufacturing process to ensure the initial accuracy of the pressure gauge. Attached Figure Description

[0015] Figure 1 This is a three-dimensional schematic diagram of the present invention; Figure 2 This is a three-dimensional schematic diagram of the present invention without a cover plate; Figure 3 This is an exploded view of the internal gears of the present invention; Figure 4 This is a cross-sectional schematic diagram of the pressure tube of the present invention.

[0016] List of reference numerals in the attached diagram: 1. Pressure tube; 2. Housing; 3. Cover plate; 4. Retaining ring; 5. Dial; 6. First pointer; 7. Second pointer; 8. End gear; 9. First double gear; 10. Second double gear; 11. Intermediate gear; 101. Threaded section; 102. First stop; 103. First piston; 104. Regular hexagonal retaining segment; 105. Tube body; 106. Large chamber; 107. Second stop; 108. First pad; 109. Small chamber; 110. Second pad; 111. Fixing nut; 112. Second piston; 113. Rack; 114. Spring; 115. Adjusting cap. Detailed Implementation

[0017] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0018] like Figures 1 to 4As shown, a high-precision hydraulic measuring instrument includes a housing 2, which is a flat cylindrical shape and has the same appearance as traditional structures. A dial 5 is provided on the front of the housing 2, and the dial 5 has two scales. The dial 5 is mounted on the inside of the housing 2 by screws or other means, i.e., a through hole is provided on the dial 5. Screw posts are provided inside the housing 2. A first pointer 6 and a second pointer 7 are provided on the front of the dial 5, corresponding to the corresponding scales on the dial 5. A reduction gear set is provided inside the dial 5, and the first pointer 6 and the second pointer 7 are mounted on the rotating shaft of the reduction gear set. The number of rotations of the first pointer 6 and the second pointer 7 are proportional; for example, when the first pointer 6 rotates one revolution, the second pointer 7 rotates one division. This form is similar to a dial indicator. By amplifying the measurement stroke, the readings are made more refined, thereby improving the measurement accuracy.

[0019] A pressure tube 1 is fixedly connected to the side wall of the outer casing 2. The pressure tube 1 is a vertically arranged tube with a smaller upper diameter and a larger lower diameter. The pressure tube 1 includes a tube body 105. The tube body 105 has a large chamber 106 and a small chamber 109 inside. The large chamber 106 is located at the bottom and the small chamber 109 is located at the top. Both are cylindrical chambers. A first piston 103 and a second piston 112 are respectively arranged inside the large chamber 106 and the small chamber 109. With this arrangement, when the pressure on the first piston 112 and the second piston 112 is the same, the distance between the second piston 112 and the first piston 103 is greater than that between the first piston 103 and the second piston 112, thereby expanding the reading range. It should be noted that liquid is filled between the first piston 103 and the second piston 112. With this structure, a seal is achieved to prevent the measured fluid from entering the interior of the outer casing 2.

[0020] A rack 113 is provided at one end of the second piston 112, and a spring 114 is sleeved on the outside of the rack 113. The spring 114 is used to reset the second piston 112 and is also the component that returns the first support 6 and the second pointer 7 to their original positions when no external force is applied. One end of the spring 114 abuts against the second piston 112, and one end of the rack 113 extends out of the tube 105. The rack 113 meshes with the input end of the reduction gear set. When the second piston 112 moves, the rack 113 extends and transmits power to the reduction gear set, thereby driving the first pointer 6 and the second pointer 7 to rotate.

[0021] The reduction gear set includes an end gear 8, a first double gear 9, an intermediate gear 10, and a second double gear 11. The small end of the second double gear 11 meshes with a rack 113, the large end of the second double gear 11 meshes with the intermediate gear 10, the intermediate gear 10 meshes with the small end of the first double gear 9, and the large end of the first double gear 9 meshes with the end gear 8. A first pointer 6 is fixed on the shaft of the end gear 8, and a second pointer 7 is fixedly connected to the shaft of the first double gear 9. In addition, corresponding sheet metal support components are provided inside the housing 2 for limiting the ends of the end gear 8, the first double gear 9, the intermediate gear 10, and the second double gear 11.

[0022] The large chamber 106 is internally threaded with a first stop 102, and the small chamber 109 is internally threaded with a second stop 107. The middle part of the first stop 102 and the second stop 107 are both hexagonal through holes.

[0023] The upper end of the tube body 105 is threadedly connected to an adjusting cap 115, and one end of the spring 114 abuts against the inner wall of the adjusting cap 115.

[0024] A first pad 108 and a second pad 110 are inserted into the tube body 105. The first pad 108 and the second pad 110 are located on the outer inner side of the outer shell 2 and are fitted to the arc surface of the outer shell 2. That is, one side of the first pad 108 and the second pad 110 is an arc surface and fits against the side wall of the outer shell 2. The first pad 108 and the second pad 110 clamp the outer shell 2. A fixing nut 111 is threaded onto the tube body 105. The fixing nut 111 is fastened to the second pad 110. By rotating the fixing nut 111, the fixed connection between the tube body 105 and the outer shell 2 is achieved.

[0025] The lower end sidewall of the tube body 105 is provided with a threaded section 101, which is used for threaded connection to the pipeline under test. The lower sidewall of the tube body 105 is provided with a regular hexagonal clamping section 104, which facilitates the use of wrenches and other workpieces to install the pressure gauge on the pipeline under test.

[0026] The front of the outer shell 2 is provided with a cover plate 3. The cover plate 3 is made of circular glass, and sealing rings are provided on both sides of the edge of the cover plate 3. A fixing ring 4 is provided on the edge of the cover plate 3. The fixing ring 4 is fixedly connected to the outer shell 2 by means of threads or adhesive. The cover plate 3 is pressed to fix it.

[0027] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A high-precision hydraulic measuring mechanical instrument, characterized in that, Includes a housing (2), on the front of the housing (2) is a dial (5), on the front of the dial (5) are a first pointer (6) and a second pointer (7), inside the dial (5) is a reduction gear set, and the first pointer (6) and the second pointer (7) are mounted on the rotating shaft of the reduction gear set, and the number of rotations of the first pointer (6) and the second pointer (7) are proportional. A pressure tube (1) is fixedly connected to the side wall of the outer shell (2). The pressure tube (1) includes a tube body (105). The tube body (105) has a large chamber (106) and a small chamber (109) inside, both of which are cylindrical chambers. A first piston (103) and a second piston (112) are respectively arranged inside the large chamber (106) and the small chamber (109). A rack (113) is provided at one end of the second piston (112). A spring (114) is sleeved on the outside of the rack (113), and one end of the spring (114) abuts against the second piston (112). One end of the rack (113) extends out of the tube body (105), and the rack (113) meshes with the input end of the reduction gear set.

2. The high-precision hydraulic measuring mechanical instrument according to claim 1, characterized in that: The reduction gear set includes an end gear (8), a first double gear (9), an intermediate gear (10), and a second double gear (11). The small end of the second double gear (11) meshes with a rack (113), and the large end of the second double gear (11) meshes with the intermediate gear (10). The small end of the intermediate gear (10) meshes with the first double gear (9), and the large end of the first double gear (9) meshes with the end gear (8). The first pointer (6) is fixed on the shaft of the end gear (8), and the second pointer (7) is fixedly connected to the shaft of the first double gear (9).

3. The high-precision hydraulic measuring mechanical instrument according to claim 1, characterized in that: The large chamber (106) is internally threaded with a first stop (102), and the small chamber (109) is internally threaded with a second stop (107). The middle part of the first stop (102) and the second stop (107) are both hexagonal through holes.

4. A high-precision hydraulic measuring mechanical instrument according to claim 1, characterized in that: The upper end of the tube (105) is threaded with an adjusting cap (115), and one end of the spring (114) abuts against the inner wall of the adjusting cap (115).

5. A high-precision hydraulic measuring mechanical instrument according to claim 1, characterized in that: A first pad (108) and a second pad (110) are inserted through the tube body (105), and the first pad (108) and the second pad (110) are located on the outer inner side of the outer shell (2) respectively, and are fitted to the arc surface of the outer shell (2). A fixing nut (111) is threaded onto the tube body (105), and the fixing nut (111) is pressed against the second pad (110).

6. A high-precision hydraulic measuring mechanical instrument according to claim 1, characterized in that: The lower end sidewall of the tube body (105) is provided with a threaded section (101), and the lower sidewall of the tube body (105) is provided with a regular hexagonal locking section (104).

7. A high-precision hydraulic measuring mechanical instrument according to claim 1, characterized in that: The front of the outer shell (2) is provided with a cover plate (3), and the edge of the cover plate (3) is provided with a fixing ring (4), which is fixedly connected to the outer shell (2).

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