A device and method for measuring the axial weight and the offset of the center of buoyancy of a float

Abstract

The application provides a device and method for measuring the axial weight and the offset of the buoyancy center of a float, which comprises two sets of weighing and lifting units, a frame crossbeam, an oil tank and floating oil. Each set of the weighing and lifting unit comprises a lifting adjusting base, a weighing device, a weight, a rope and a fixed pulley. The float is hung on the end of the rope on both sides of the measuring device and placed in the empty oil tank, the float is kept in a horizontal state by adjusting the lifting adjusting bases on both sides, the axial position of the center of gravity of the float is determined according to the reading of the weighing device and the principle of static balance, the oil tank is filled with floating oil, the float is suspended in the floating oil, the float is kept in a horizontal state by adjusting the lifting adjusting bases on both sides, the axial position of the buoyancy center of the float is determined according to the reading of the weighing device and the principle of static balance, and the axial weight and the offset of the buoyancy center of the float are determined. The measuring device and method are fast in operation and simple in structure, and the axial weight and the offset of the buoyancy center of the float can be accurately obtained with the aid of a high-precision electronic balance.

Description

Technical Field

[0001] This invention belongs to the field of float axial weight and buoyancy center offset measurement technology, and specifically relates to a float axial weight and buoyancy center offset measurement device and method. Background Technology

[0002] Liquid-float instruments are suitable for high overload and high dynamic conditions, and are mainly used in rockets and other applications. Liquid-float instruments achieve high precision by employing liquid-float technology, where the float suspends itself in floating oil through liquid buoyancy, thereby minimizing the impact of disturbing torques. For a liquid-float instrument float, when its axial center of gravity and center of buoyancy do not coincide, it will tilt within the floating oil. In this case, the magnetic levitation devices at both ends of the float will exert force to keep the float balanced. The continuous force applied by the magnetic levitation devices will increase the system temperature and power consumption. If the float tilt is within the dead zone of the magnetic levitation device's displacement detection, it cannot be effectively controlled, thus affecting the instrument's measurement accuracy.

[0003] The traditional method for balancing a float involves placing it in a slightly denser oil layer (slightly denser than the float) so that it floats on the surface. The oil is then continuously heated, gradually immersing the float. The operator observes the moment the float's upper surface detaches from the oil surface as it sinks, using this information to determine the location and amount of weight to be removed. The float is then placed back into the oil for observation, and this process is repeated until the float reaches equilibrium. However, this method cannot quantify the float's center of gravity or axial offset, requiring repeated weight removal and observation, resulting in low efficiency. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the inventors have conducted intensive research and provided a device and method for measuring the axial weight and buoyancy center offset of a float, which can efficiently and accurately measure the axial weight and buoyancy center offset of a float.

[0005] The technical solution provided by this invention is as follows:

[0006] In a first aspect, a device for measuring the axial weight and buoyancy center offset of a float includes: two sets of weighing and lifting units, a frame beam, an oil tank, and floating oil; the two sets of weighing and lifting units are symmetrically arranged relative to the oil tank, and each set of weighing and lifting units includes a lifting and adjusting base, a weighing device, weights, ropes, and a fixed pulley;

[0007] The frame beam, fixed pulleys, and ropes are used together. The frame beam is installed on the workbench, and two sets of fixed pulleys are fixed on both sides of the frame beam. Each rope is suspended on a set of fixed pulleys, with one end connected to a float and the other end connected to a weight.

[0008] The weights are placed on the weighing device, and the two work together to weigh the float during the balancing process.

[0009] The weighing device is placed on the lifting and adjusting base, and the lifting and adjusting base adjusts the height of the weighing device so that the float is in a horizontal state.

[0010] The floating oil is placed in an oil tank. The density of the floating oil is less than that of the float, so as to provide buoyancy for the float immersed in it.

[0011] When no floating oil is added to the oil tank, the float is lifted by a weighing and lifting unit and kept in a horizontal position. The coordinates of the center of gravity of the float along the axial direction are obtained through static balance and torque balance relationships. After floating oil is added to the oil tank, the float is lifted by a weighing and lifting unit and kept in a horizontal position. The coordinates of the center of buoyancy of the float along the axial direction are obtained through static balance and torque balance relationships, combined with the expression of the float's weight when no floating oil is added to the oil tank. The axial weight and the offset of the center of buoyancy of the float are then obtained.

[0012] Secondly, a method for measuring the axial weight and buoyancy center offset of a float, implemented using the float axial weight and buoyancy center offset measuring device described in the first aspect, includes the following steps:

[0013] The float is weighed directly using a weighing device, and its mass is recorded.

[0014] Without adding floating oil to the oil tank, set the suspension point of one end of the float as the origin and record the axial coordinate of the suspension point of the other end of the float; suspend the suspension points of both ends of the float to the ends of two ropes respectively, and connect the other ends of the ropes to the weights. Adjust the lifting adjustment bases on both sides to make the float horizontal and record the readings of the weighing devices on both sides to establish static balance and torque balance relationship, and obtain the position coordinates of the center of gravity of the float in the axial direction.

[0015] Add floating oil to the oil tank and make the floating oil completely submerge the float. Adjust the lifting adjustment bases on both sides again to make the float horizontal and record the readings of the weighing devices on both sides to establish static balance and torque balance relationship, and obtain the position coordinates of the float center in the axial direction.

[0016] The axial weight and the offset of the buoy's center of gravity and the buoyancy center are obtained by subtracting their position coordinates in the axial direction.

[0017] The device and method for measuring the axial weight and buoyancy center offset of a float provided by the present invention have the following beneficial effects:

[0018] (1) The present invention provides a device and method for measuring the axial weight and buoyancy center offset of a float, which can be divided into two aspects to quantify the measurement results. First, when no floating oil is added to the oil tank, the position coordinates of the float's center of gravity are obtained through the principles of static balance and torque balance. Second, after floating oil is added to the oil tank, the position coordinates of the float's buoyancy center are obtained through the principles of static balance and torque balance combined with the results of the first aspect. The difference between the two is used to obtain the axial weight and buoyancy center offset of the float. The expression for the weight and buoyancy center position coordinates does not contain f. 摩 This indicates that the measurement of the axial weight and buoyancy center offset of the float can offset some of the influence of the system error of the device, thus improving the measurement accuracy;

[0019] (2) The present invention provides a float axial weight and float center offset measuring device and method. The float weight and float center offset measuring device satisfies the requirements of maintaining the horizontal state of the float and measuring related parameters under the conditions of no floating oil in the oil tank and floating oil in the oil tank. The measurement process is simple and quick to operate, and the float weight and float center offset can be obtained quickly, shortening the axial balance cycle.

[0020] (3) The present invention provides a device and method for measuring the axial weight and buoyancy center offset of a float. By adjusting the arrangement of the base, the lifting platform can be raised and lowered smoothly to adjust the position and height of the weighing device, change the length of the end of the float suspended by the non-elastic rope, and quickly and stably make the float reach a horizontal state. Attached Figure Description

[0021] Figure 1 Schematic diagram of the device for measuring the axial weight and buoyancy center offset of the float;

[0022] Figure 2 Diagram of the lifting and adjusting base structure;

[0023] Figure 3 Flowchart of the method for measuring the axial weight and buoyancy center offset of the float;

[0024] Figure 4 This is a schematic diagram of the axial coordinates of the float. Detailed Implementation

[0025] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0026] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0027] like Figure 1As shown, the present invention provides a device for measuring the axial weight and buoyancy center offset of a float, comprising: two sets of weighing and lifting units, a frame beam 6, an oil tank 7 and floating oil 8; the two sets of weighing and lifting units are symmetrically arranged relative to the oil tank 7, and each set of weighing and lifting units includes a lifting and adjusting base 1, a weighing device 2, a weight 3, a rope 4 and a fixed pulley 5;

[0028] The frame beam 6, fixed pulleys 5 and ropes 4 are used together. The frame beam 6 is installed on the workbench. Two sets of fixed pulleys 5 are fixed on both sides of the frame beam 6 respectively. Each rope 4 is suspended on a set of fixed pulleys 5, with one end connected to a float and the other end connected to a weight 3.

[0029] The weight 3 is placed on the weighing device 2, and the two work together to weigh the float during the balancing process.

[0030] The weighing device 2 is placed on the lifting and adjusting base 1, and the lifting and adjusting base 1 adjusts the height of the weighing device 2 so that the float is in a horizontal state.

[0031] The floating oil 8 is placed in the oil tank 7. The density of the floating oil 8 is less than that of the float, so as to provide buoyancy for the float immersed in it.

[0032] When no floating oil is added to the oil tank, the float is lifted by a weighing and lifting unit and kept in a horizontal position. The coordinates of the center of gravity of the float along the axial direction are obtained through static balance and torque balance relationships. After floating oil is added to the oil tank, the float is lifted by a weighing and lifting unit and kept in a horizontal position. The coordinates of the center of buoyancy of the float along the axial direction are obtained through static balance and torque balance relationships, combined with the expression of the float's weight when no floating oil is added to the oil tank. The axial weight and the offset of the center of buoyancy of the float are then obtained.

[0033] In a preferred embodiment, each set of fixed pulleys 5 includes at least two fixed pulleys. The distance between the vertical tangents of the two fixed pulleys 5 near the center of the device is equal to the distance between the suspension points on both sides of the float, so that the float bears a vertically upward pulling force. The oil tank 7 is placed between the two lifting and adjusting bases 1.

[0034] To facilitate adjustment of the float's state, the two sets of fixed pulleys are of equal number, and the distance between the pulleys in the two sets of fixed pulleys is equal.

[0035] In a preferred embodiment, the rope 4 is a non-elastic rope with a diameter of 0.2–1 mm. To facilitate adjustment of the float's state, the ropes 4 in the two sets of weighing and lifting units are of equal length.

[0036] In a preferred embodiment, the weighing device 2 is an automatic weighing device such as an electronic balance.

[0037] like Figure 2As shown, the lifting and adjusting base 1 includes multiple components such as three or four support feet 1-1, base 1-2, lifting platform 1-6, at least one guide rod 1-12, at least one sliding sleeve 1-11, screw sleeve 1-5, lead screw 1-7, knob 1-8, upper bearing 1-10, upper bearing seat 1-9, lower bearing 1-4, lower bearing seat 1-3, and bracket 1-13. Support foot 1-1 supports base 1-2; bracket 1-13 is installed on base 1-2; screw sleeve 1-5 and lead screw 1-7 are screwed together, screw sleeve 1-5 is fixed to lifting platform 1-6, upper bearing 1-10 and lower bearing 1-4 are respectively installed at both ends of lead screw 1-7, upper bearing 1-10 is installed on upper bearing seat 1-9, lower bearing 1-4 is installed on lower bearing seat 1-3, upper bearing seat 1-9 and lower bearing seat 1-3 are respectively installed on bracket 1-13 and base 1-2, guide rod 1-12 is installed on base 1-2, sliding sleeve 1-11 is installed on lifting platform 1-6 and slidably connected to guide rod 1-12; rotating knob 1-8 drives lead screw 1-7 to rotate, so that lifting platform 1-6 rises or falls.

[0038] Since the lifting platform 1-6 carries a weighing device, in order to avoid the weighing device, the guide rod 1-12 is installed on the edge of the base 1-2, and the sliding sleeve 1-11 is installed on the edge of the lifting platform 1-6.

[0039] The lifting and adjusting base can also take other forms, such as a lifting bracket powered by a cylinder, as long as it can smoothly drive the weighing device on it to move up and down.

[0040] This invention also provides a method for measuring the axial weight and buoyancy center offset of a float, such as... Figure 3 As shown, it includes:

[0041] Step 1: Weigh the float directly using a weighing device and record the float's mass m. 重 ;

[0042] Step 2: The two weights selected each have a mass of m. 码 , requires m 码 >m 重 / 2. No floating oil is added to the oil tank. The point where one end of the float is suspended is set as the origin, i.e., X1 = 0. The axial direction of the float is set as the x-direction. The axial coordinate of the other end of the float is X2. See... Figure 4 The float is suspended from two ropes at its two ends, with the other ends of the ropes connected to weights. The float is brought to a horizontal position by adjusting the lifting bases on both sides, and the readings of the weighing devices on both sides are recorded as m1 and m2. Based on the relationships of static equilibrium and torque equilibrium, the following equation is established:

[0043] m 重 g=(m 码 -m1)g+(m 码-m2)g+f 摩 (1)

[0044]

[0045] From equations (1) and (2), we can obtain:

[0046]

[0047] In the formula, f 摩 X represents the frictional force exerted by the fixed pulleys on both sides of the frame beam on the two ropes. 重 The coordinates of the float's center of gravity in the axial direction.

[0048] Step 3: Add floating oil to the oil tank, ensuring the oil completely submerges the float. Adjust the lifting bases on both sides again to bring the float to a horizontal position. Record the readings of the weighing devices on both sides as m3 and m4, respectively. Here, m3 and m1 are readings from the same weighing device, and m4 and m2 are readings from the same weighing device. Based on the static equilibrium and torque equilibrium relationships, establish the following equation:

[0049] m 重 g=(m 码 -m3)g+(m 码 -m4)g+f 摩 +F 浮 (4)

[0050]

[0051] From equations (1), (2), (4), and (5), we can obtain:

[0052]

[0053] In the formula, F 浮 X represents the buoyancy of the floating oil on the float. 浮 The coordinates of the buoyancy center in the axial direction are given.

[0054] Step 4: According to equations (3) and (6), the axial weight of the float and the offset of the buoyancy center d can be obtained:

[0055]

[0056] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0057] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A device for measuring the axial weight and buoyancy center offset of a float, characterized in that, include: Two sets of weighing and lifting units, frame beam (6), oil tank (7) and floating oil (8); the two sets of weighing and lifting units are symmetrically arranged relative to the oil tank 7. Each set of weighing and lifting units includes a lifting and adjusting base (1), weighing device (2), weight (3), rope (4) and fixed pulley (5); The frame beam (6), fixed pulleys (5) and ropes (4) are used together. The frame beam (6) is installed on the workbench. Two sets of fixed pulleys (5) are fixed on both sides of the frame beam (6). Each rope (4) is suspended on a set of fixed pulleys (5), with one end connected to a float and the other end connected to a weight (3). The weight (3) is placed on the weighing device (2), and the two work together to weigh the float during the balancing process. The weighing device (2) is placed on the lifting adjustment base (1), and the lifting adjustment base (1) adjusts the height of the weighing device (2) so that the float is in a horizontal state. The floating oil (8) is placed in the oil tank (7). The density of the floating oil (8) is less than that of the float, so as to provide buoyancy for the float immersed in it. When no floating oil is added to the oil tank, the float is lifted by a weighing and lifting unit and kept in a horizontal position. The coordinates of the center of gravity of the float along the axial direction are obtained through static balance and torque balance relationships. After floating oil is added to the oil tank, the float is lifted by a weighing and lifting unit and kept in a horizontal position. The coordinates of the center of buoyancy of the float along the axial direction are obtained through static balance and torque balance relationships, combined with the expression of the float's weight when no floating oil is added to the oil tank. The axial weight and the offset of the center of buoyancy of the float are then obtained.

2. The float axial weight and buoyancy center offset measuring device according to claim 1, characterized in that, Each weighing and lifting unit includes at least two fixed pulleys. The distance between the vertical tangents of the two fixed pulleys (5) closest to the float and the center side of the device is equal to the distance between the suspension points on both sides of the float, so that the rope (4) connecting the float end is pulled vertically upward.

3. The float axial weight and buoyancy center offset measuring device according to claim 1, characterized in that, The rope (4) is a non-elastic rope.

4. The float axial weight and buoyancy center offset measuring device according to claim 1, characterized in that, The ropes (4) in the two sets of weighing and lifting units are of equal length.

5. The float axial weight and buoyancy center offset measuring device according to claim 1, characterized in that, The lifting and adjusting base (1) includes multiple support feet (1-1), a base (1-2), a lifting platform (1-6), at least one guide rod (1-12), at least one sliding sleeve (1-11), a screw sleeve (1-5), a lead screw (1-7), a knob (1-8), an upper bearing (1-10), an upper bearing seat (1-9), a lower bearing (1-4), a lower bearing seat (1-3), and a bracket (1-13); the support feet (1-1) support the base (1-2); the bracket (1-13) is installed on the base (1-2); the screw sleeve (1-5) and the lead screw (1-7) are screwed together, and the screw sleeve (1-5) is connected to the lifting platform (1-6). 1-6) Fixed connection: The upper bearing (1-10) and the lower bearing (1-4) are respectively installed at both ends of the lead screw (1-7). The upper bearing (1-10) is installed on the upper bearing seat (1-9), and the lower bearing (1-4) is installed on the lower bearing seat (1-3). The upper bearing seat (1-9) and the lower bearing seat (1-3) are respectively installed on the bracket (1-13) and the base (1-2). The guide rod (1-12) is installed on the base (1-2). The sliding sleeve (1-11) is installed on the lifting platform (1-6) and is slidably connected with the guide rod (1-12). Rotate the knob (1-8) to drive the lead screw (1-7) to rotate, so that the lifting platform (1-6) rises or falls.

6. The float axial weight and buoyancy center offset measuring device according to claim 5, characterized in that, The guide rod (1-12) is installed on the edge of the base (1-2), and the sliding sleeve (1-11) is installed on the edge of the lifting platform (1-6).

7. A method for measuring the axial weight and buoyancy center offset of a float, characterized in that, The float axial weight and buoyancy center offset measuring device according to any one of claims 1 to 6 includes: The float is weighed directly using a weighing device, and its mass is recorded. Without adding floating oil to the oil tank, set the suspension point of one end of the float as the origin and record the axial coordinate of the suspension point of the other end of the float; suspend the suspension points of both ends of the float to the ends of two ropes respectively, and connect the other ends of the ropes to the weights. Adjust the lifting adjustment bases on both sides to make the float horizontal and record the readings of the weighing devices on both sides to establish static balance and torque balance relationship, and obtain the position coordinates of the center of gravity of the float in the axial direction. Add floating oil to the oil tank and make the floating oil completely submerge the float. Adjust the lifting adjustment bases on both sides again to make the float horizontal and record the readings of the weighing devices on both sides. Establish the static balance and torque balance relationship and obtain the position coordinates of the float center in the axial direction. The axial weight and the offset of the buoy's center of gravity and the buoyancy center are obtained by subtracting their position coordinates in the axial direction.

8. The method for measuring the axial weight and buoyancy center offset of a float according to claim 7, characterized in that, When no floating oil is added to the oil tank, the expressions for the static balance and torque balance relationships are as follows: m 重 g=(m 码 -m1)g+(m 码 -m2)g+f 摩 (1) The coordinates of the float's center of gravity in the axial direction are: Where, m 重 m is the mass of the float; m1 and m2 are the readings of the weighing devices on both sides when there is no buoyancy; m 码 Let m be the mass of the two weights. 码 >m 重 / 2;f 摩 X1 represents the frictional force exerted by the fixed pulleys on both sides of the frame beam on the two ropes; X2 represents the axial coordinate of the suspension point of the float at the non-origin end; X... 重 The coordinates of the float's center of gravity in the axial direction.

9. The method for measuring the axial weight and buoyancy center offset of a float according to claim 8, characterized in that, When floating oil is added to the oil tank, the expression for the static balance and torque balance relationship is: m 重 g=(m 码 -m3)g+(m 码 -m4)g+f 摩 +F 浮 (4) Using equations (1), (2), (4), and (5), the coordinates of the buoyancy center in the axial direction can be obtained as follows: In the formula, m3 and m4 are the readings of the weighing devices on both sides when buoyancy exists, where m3 and m1 are the readings of the same weighing device, and m4 and m2 are the readings of the same weighing device; F 浮 X represents the buoyancy of the floating oil on the float. 浮 The coordinates of the buoyancy center in the axial direction are given.

10. The method for measuring the axial weight and buoyancy center offset of a float according to claim 9, characterized in that, The axial weight of the float and the offset of the buoyancy center are:

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