Device and method for measuring axial weight and buoyancy center offset of floater

Abstract

The invention provides a floater axial weight and buoyancy center offset measuring device and method. The measuring device comprises two sets of weighing hoisting units, a frame cross beam, an oil groove and floating oil. Each group of weighing and hoisting unit comprises a lifting adjusting base, a weighing device, a weight, a rope and a fixed pulley; firstly, floaters are hung at the tail ends of ropes on the two sides of the measuring device and placed in an empty oil groove, the floaters are kept in a horizontal state by adjusting lifting adjusting bases on the two sides, and the axial position of the gravity center of the floaters is determined according to the reading of a weighing device and the static balance principle; then floating oil is injected into the oil tank, the floater is made to suspend in the floating oil, the lifting adjusting bases on the two sides are adjusted to enable the floater to be kept in the horizontal state, the axial position of the buoyancy center of the floater is determined according to the reading of the weighing device and the static balance principle, and finally the axial weight and the buoyancy center offset of the floater are determined. The measuring device and method provided by the invention are quick to operate and simple in structure, and the axial weight and buoyancy center offset of the floater can be accurately obtained by means of the high-precision electronic balance.

Description

Technical Field

[0001] The invention belongs to the technical field of measuring the axial weight and buoyancy center offset of a float, and in particular relates to a device and a method for measuring the axial weight and buoyancy center offset of a float. Background Art

[0002] Liquid floating instruments are suitable for large overload and high dynamic conditions, and are mainly used in rockets, etc. Liquid floating instruments use liquid floating technology to achieve high-precision performance, in which the float is suspended in the floating oil through the liquid floating effect, thereby minimizing the influence of the interference torque. For the float of the liquid floating instrument, when the axial center of gravity and the center of buoyancy do not coincide, it will tilt in the floating oil. At this time, the magnetic suspension devices at both ends of the float will exert force to keep the float balanced. The continuous force of the magnetic suspension device will increase the temperature of the system and increase the power consumption. If the tilt of the float is in the dead zone of the displacement detection of the magnetic suspension device, it will not be effectively controlled, thereby affecting the measurement accuracy of the instrument.

[0003] The traditional method of balancing the float axially is to put the float into the floating oil, the density of which is slightly greater than that of the float, so that the float floats on the surface of the floating oil, and continue to heat the floating oil so that the float gradually immerses in the floating oil. When the float sinks, the balance state of its upper surface is observed when it leaves the floating oil surface. Based on this, the operator's experience is used to judge the deweighting position and deweighting quality, and then the deweighted float is put into the floating oil again for observation, and this process is repeated until the float reaches balance. This operation process cannot quantify the center of gravity and axial displacement of the float, and it is necessary to repeatedly deweight and observe, and the balancing process is inefficient. Summary of the invention

[0004] In order to overcome the deficiencies in 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 complete the measurement of the axial weight and buoyancy center offset of the float.

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

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

[0007] The frame beam, fixed pulley and rope are used in combination. The frame beam is installed on the work surface. Two sets of fixed pulleys are respectively fixed on both sides of the frame beam. Each rope is suspended on a set of fixed pulleys, one end of which is connected to a float and the other end is connected to a weight.

[0008] The weight is placed on the weighing device, and the two are used together for weighing during the float balancing process;

[0009] The weighing device is placed on a 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 contained in the oil tank, the density of the floating oil is less than the density of the float, and provides buoyancy for the float immersed in the floating oil;

[0011] When no floating oil is added to the oil tank, the float is lifted by the weighing and lifting unit and is in a horizontal state, and the center of gravity coordinates of the float along the axial direction are obtained through the static balance and moment balance relationship; after the floating oil is added to the oil tank, the float is lifted by the weighing and lifting unit and is in a horizontal state, and the center of buoyancy coordinates of the float along the axial direction are obtained through the static balance and moment balance relationship combined with the float gravity expression when no floating oil is added to the oil tank, and the axial weight and center of buoyancy offset of the float are obtained.

[0012] In a second aspect, a method for measuring the axial weight and buoyancy center offset of a float is implemented by using the device for measuring the axial weight and buoyancy center offset of a float described in the first aspect, and comprises the following steps:

[0013] Use a weighing device to directly weigh the float and record the mass of the float;

[0014] No floating oil is added to the oil tank, the suspension point at one end of the float is set as the origin, and the axial coordinates of the suspension point at the other end of the float are recorded; the suspension points at both ends of the float are respectively suspended at one end of two ropes, and the other ends of the ropes are connected to weights. The float is kept in a horizontal state by adjusting the lifting adjustment bases on both sides, and the readings of the weighing devices on both sides are recorded, and the static balance and moment balance relationships are established to 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 immerse the float, adjust the lifting adjustment bases on both sides again to make the float in a horizontal state, and record the readings of the weighing devices on both sides, establish the static balance and moment balance relationship, and obtain the position coordinates of the float center in the axial direction;

[0016] The position coordinates of the center of gravity and the center of buoyancy of the float in the axial direction are subtracted to obtain the axial weight and the center of buoyancy offset of the float.

[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 float axial weight and buoyancy center offset measurement device and method, which can be generally divided into two aspects to achieve quantification of measurement results. First, when no floating oil is added to the oil tank, the position coordinates of the float center of gravity are obtained by the static balance and moment balance principles; second, after the floating oil is added to the oil tank, the position coordinates of the float center of buoyancy are obtained by the static balance and moment balance principles combined with the results of the first aspect, and the difference between the two is obtained to obtain the float axial weight and buoyancy center offset; the weight and buoyancy center position coordinate expressions do not contain f 摩 , indicating that the measurement of the float axial weight and buoyancy center offset can offset the influence of part of the device system error and improve the measurement accuracy;

[0019] (2) The present invention provides a float axial weight and buoyancy center offset measurement device and method. The float weight and buoyancy center axial offset measurement device can maintain the horizontal state of the float and measure related parameters when there is no floating oil in the oil tank or when there is floating oil in the oil tank, making the measurement process simple and quick to operate. The float weight and buoyancy center axial offset can be obtained quickly, shortening the axial balance period.

[0020] (3) The present invention provides a device and method for measuring the axial weight and center of buoyancy offset of a float. By adjusting the base arrangement by lifting and lowering, the smooth lifting and lowering of the lifting platform can be ensured, so as to adjust the position height of the weighing device and change the length of one end of the float suspended by the inelastic rope, so as to quickly and stably make the float reach a horizontal state. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the device for measuring the axial weight and buoyancy center offset of the float;

[0022] Figure 2 The structural diagram of the base for lifting and adjusting;

[0023] Figure 3 It is a flow chart of the method for measuring the axial weight and buoyancy center offset of the float;

[0024] Figure 4 It is a schematic diagram of the axial coordinates of the float. DETAILED DESCRIPTION

[0025] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0026] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over 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 hoisting units, a frame crossbeam 6, an oil tank 7 and floating oil 8; the two sets of weighing and hoisting units are symmetrically arranged relative to the oil tank 7, and each set of weighing and hoisting units comprises 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, the fixed pulley 5 and the rope 4 are used in combination. The frame beam 6 is installed on the work surface. Two sets of fixed pulleys 5 are respectively fixed on both sides of the frame beam 6. Each rope 4 is suspended on a set of fixed pulleys 5, one end of which is connected to a float and the other end is connected to a weight 3.

[0029] The weight 3 is placed on the weighing device 2, and the two are used together for weighing during the float balancing process;

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

[0031] The floating oil 8 is contained in the oil tank 7, and the density of the floating oil 8 is less than that of the float, so as to provide buoyancy for the float immersed therein;

[0032] When no floating oil is added to the oil tank, the float is lifted by the weighing and lifting unit and is in a horizontal state, and the center of gravity coordinates of the float along the axial direction are obtained through the static balance and moment balance relationship; after the floating oil is added to the oil tank, the float is lifted by the weighing and lifting unit and is in a horizontal state, and the center of buoyancy coordinates of the float along the axial direction are obtained through the static balance and moment balance relationship combined with the float gravity expression when no floating oil is added to the oil tank, and the axial weight and center of buoyancy offset of the float are obtained.

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

[0034] In order to facilitate the adjustment of the float state, the two groups of fixed pulleys 5 are equal in number and the pulley spacings in the two groups of fixed pulleys are equal.

[0035] In a preferred embodiment, the rope 4 is a non-elastic rope with a diameter of 0.2-1 mm. In order to facilitate the adjustment of the float 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 parts such as three or four supporting 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 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 supporting foot 1-1 supports the base 1-2; a bracket 1-13 is installed on the base 1-2; the screw sleeve 1-5 and the lead screw 1-7 are spirally matched, the screw sleeve 1-5 is fixedly connected to the lifting platform 1-6, and the upper bearing 1-10 and the lower bearing 1-4 are installed at both ends of the lead screw 1-7, respectively. 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, and the sliding sleeve 1-11 is installed on the lifting platform 1-6 and is slidably connected with the guide rod 1-12; rotating the knob 1-8 drives the lead screw 1-7 to rotate, so that the 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 may also be in other forms, such as a lifting bracket with a cylinder as a power source, etc., which can smoothly drive the weighing device thereon to move up and down.

[0040] The present invention also provides a method for measuring the axial weight and buoyancy center offset of a float. Figure 3 As shown, including:

[0041] Step 1: Use a weighing device to weigh the float directly and record the float mass m 重 ;

[0042] Step 2: The two weights are both m in mass. 码 , requiring m 码 >m 重 / 2. No floating oil is added to the oil tank, the suspension point at one end of the float is set as the origin, that is, X1 = 0, the axial direction of the float is set as the x direction, and the axial coordinate of the suspension point at the other end of the float is X2, see Figure 4 The two ends of the float are suspended at the ends of two ropes, and the other ends of the ropes are connected to the weights. The float is in a horizontal state by adjusting the lifting adjustment bases on both sides, and the readings of the weighing devices on both sides are recorded as m1 and m2 respectively. According to the relationship between static balance and moment balance, the following equation is established:

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

[0044]

[0045] By using formula (1) and formula (2), we can get:

[0046]

[0047] In the formula, f 摩 is the friction force of the fixed pulleys on both sides of the frame beam on the two ropes; X 重 is the position coordinate of the float's center of gravity in the axial direction.

[0048] Step 3: Add floating oil to the oil tank and make sure that the floating oil completely immerses the float. Adjust the lifting and adjusting bases on both sides again to make the float in a horizontal state, and record the readings of the weighing devices on both sides as m3 and m4, where m3 and m1 are the readings of the same weighing device, and m4 and m2 are the readings of the same weighing device. According to the relationship between static balance and moment balance, establish the following equation:

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

[0050]

[0051] Through formula (1), formula (2), formula (4) and formula (5), we can get:

[0052]

[0053] In the formula, F 浮 is the buoyancy of the floating oil on the float; X 浮 is the position coordinate of the float center in the axial direction.

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

[0055]

[0056] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0057] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A float axial weight and buoyancy center offset measuring device, characterized in that: include: Two sets of weighing and hoisting units, a frame crossbeam (6), an oil tank (7) and floating oil (8); the two sets of weighing and hoisting units are symmetrically arranged relative to the oil tank 7, and each set of weighing and hoisting units includes a lifting and adjusting base (1), a weighing device (2), a weight (3), a rope (4) and a fixed pulley (5); The frame beam (6), the fixed pulley (5) and the rope (4) are used in combination, the frame beam (6) is installed on the work surface, the two sets of fixed pulleys (5) are respectively fixed on both sides of the frame beam (6), each rope (4) is suspended on a set of fixed pulleys (5), one end of which is connected to a float and the other end is connected to a weight (3); The weight (3) is placed on the weighing device (2), and the two are used together for weighing during the float balancing process; The weighing device (2) is placed on a 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; The floating oil (8) is contained in the oil tank (7), the density of the floating oil (8) is less than the density of the float, and provides buoyancy for the float immersed in the floating oil (8); When no floating oil is added to the oil tank, the float is lifted by the weighing and lifting unit and is in a horizontal state, and the center of gravity coordinates of the float along the axial direction are obtained through the static balance and moment balance relationship; after the floating oil is added to the oil tank, the float is lifted by the weighing and lifting unit and is in a horizontal state, and the center of buoyancy coordinates of the float along the axial direction are obtained through the static balance and moment balance relationship combined with the float gravity expression when no floating oil is added to the oil tank, and the axial weight and center of buoyancy offset of the float are obtained.

2. The device for measuring the axial weight and buoyancy center offset of a float according to claim 1, characterized in that: Each set of weighing and hoisting units includes at least two fixed pulleys, and the distance between the vertical tangents of the two fixed pulleys (5) close to the float and close to the center side of the device is equal to the distance between the suspension points on both sides of the float, so that the tension of the rope (4) connected to the float end is vertically upward.

3. The device for measuring the axial weight and buoyancy center offset of a float according to claim 1, characterized in that: The rope (4) is a non-elastic rope, preferably with a diameter of 0.2 to 1 mm.

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

5. The device for measuring the axial weight and buoyancy center offset of a float according to claim 1, characterized in that: The lifting adjustment base (1) comprises a plurality of supporting 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 supporting 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 screw-matched, and the screw sleeve (1-5) and the lifting platform (1-13) are screw-matched. 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), 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); the knob (1-8) is rotated to drive the lead screw (1-7) to rotate, so that the lifting platform (1-6) rises or falls.

6. The device for measuring the axial weight and buoyancy center offset of a float 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 device for measuring the axial weight and buoyancy center offset of a float according to any one of claims 1 to 6 comprises: Use a weighing device to directly weigh the float and record the mass of the float; No floating oil is added to the oil tank, the suspension point at one end of the float is set as the origin, and the axial coordinates of the suspension point at the other end of the float are recorded; the suspension points at both ends of the float are respectively suspended at one end of two ropes, and the other ends of the ropes are connected to weights. The float is kept in a horizontal state by adjusting the lifting adjustment bases on both sides, and the readings of the weighing devices on both sides are recorded, and the static balance and moment balance relationships are established to 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 immerse the float, adjust the lifting adjustment bases on both sides again to make the float in a horizontal state, and record the readings of the weighing devices on both sides, establish the static balance and moment balance relationship, and obtain the position coordinates of the float center in the axial direction; The position coordinates of the center of gravity and the center of buoyancy of the float in the axial direction are subtracted to obtain the axial weight and the center of buoyancy offset of the float.

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 expression of the static balance and moment balance relationship is: m 重 g=(m 码 -m1)g+(m 码 -m2)g+f 摩 (1) The position coordinates of the float center of gravity in the axial direction are: Among them, m 重 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 is the mass of the two weights, m 码 >m 重 / 2;f 摩 is the friction force of the fixed pulleys on both sides of the frame beam on the two ropes; X2 is the axial coordinate of the suspension point of the non-origin end of the float; X 重 is the position coordinate of the center of gravity of the float 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 of the static balance and moment balance relationship is: m 重 g=(m 码 -m3)g+(m 码 -m4)g+f 摩 +F 浮 (4) Through equations (1), (2), (4) and (5), the position coordinates of the float center in the axial direction can be obtained as follows: Where m3 and m4 are the readings of the weighing devices on both sides when buoyancy exists, 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 is the buoyancy of the floating oil on the float; X 浮 is the position coordinate of the float center in the axial direction.

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 and buoyancy center offset of the float are:

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