A piezoelectric sensing device and measurement method for measuring the backfat thickness of pigs

Abstract

The present invention discloses a piezoelectric sensing device and a measuring method for measuring the backfat thickness of pigs. The piezoelectric sensing device for measuring the backfat thickness of pigs includes an upper piezoelectric film, a housing, a thin plate, a lower piezoelectric film, a rubber gasket, a measuring head, a limiting block, and a snap ring. Except for the snap ring, the above-mentioned parts are all rotating bodies, and the above-mentioned parts are all coaxially installed, and the overall device is a centrosymmetric structure. Based on the piezoelectric effect, the present invention has the advantages of high detection accuracy, low manufacturing cost, easy to carry, and simple operation, and can effectively improve the detection efficiency of pig backfat and reduce the stress response of pigs.

Description

Technical Field:

[0001] The present invention relates to a piezoelectric sensing device and a measurement method for measuring the backfat thickness of pigs, which belong to the field of biomechanical detection. Background Art:

[0002] In China, the meat production has been continuously increasing, and the quality and safety of meat products have attracted much attention. The fat condition of live pigs is an important basis for measuring nutrition and energy storage. The backfat is significantly correlated with carcass fat, body condition score and reproductive performance, and is an important indicator for pig genetic breeding and performance evaluation. Maintaining a good body condition and backfat level can improve the reproductive ability of live pigs, enhance production performance and increase the income of pig farms.

[0003] In the prior art, the backfat thickness of pigs is mainly detected by using a backfat caliper or an ultrasonic instrument, and the types and consumption amounts of pig feed are adjusted according to the backfat thickness of pigs, so as to improve the efficiency of pig raising. In fact, the cost of using a backfat caliper is relatively low, but the detection accuracy of measuring the backfat thickness of pigs is relatively low; the detection of the backfat thickness of pigs by using an ultrasonic instrument is expensive, and it is difficult for small-scale pig farmers to purchase such equipment. Moreover, the operation of the ultrasonic instrument and the interpretation of the images generated by the ultrasonic instrument both require the staff to have certain professional knowledge and cultural background, which brings great inconvenience to small-scale farmers.

[0004] Therefore, there is an urgent need for a high-precision pig backfat measurement device with low manufacturing cost and simple device operation to improve the efficiency of pig backfat measurement. Summary of the Invention:

[0005] The present invention provides a piezoelectric sensing device and a measurement method for measuring the backfat thickness of pigs to effectively reduce the measurement cost of pig backfat and improve the measurement efficiency of pig backfat in order to solve the problems existing in the above prior art.

[0006] The present invention adopts the following technical solution: A piezoelectric sensing device for measuring the backfat thickness of pigs, comprising an upper piezoelectric film, a housing, a thin plate, a lower piezoelectric film, a rubber washer, a measuring head, a limiting block and a snap ring. The housing is in a cylindrical shape. A first circular groove is formed by recessing at the middle position of the upper end of the housing. The upper piezoelectric film is a circular plate body, and the upper piezoelectric film completely covers the first circular groove. A circular receiving hole extending downward is formed inside the housing. The circular receiving hole includes a first receiving hole and a second receiving hole connected to the first receiving hole and located below the first receiving hole. The thin plate is installed at the upper end of the second receiving hole and adjacent to the position of the first receiving hole. A second circular groove is formed by recessing at the middle position of the lower end of the thin plate. The lower piezoelectric film is pasted at the middle position of the thin plate. The lower piezoelectric film is a circular plate body, and the lower piezoelectric film completely covers the second circular groove. Rubber washers are pasted at the positions around the lower piezoelectric film on the thin plate. A snap ring groove for installing the snap ring is formed by recessing on the inner side wall of the second receiving hole. The limiting block is clamped between the thin plate and the snap ring. The limiting block is in close contact with the thin plate. A through hole penetrating through the upper and lower side walls of the limiting block is formed inside the limiting block. A spherical protrusion is formed at the center position of the upper end of the measuring head. The spherical protrusion is coated with an insulating material. The measuring head is installed in the through hole. The lower end of the measuring head extends beyond the lower end of the limiting block and then extends into the second receiving hole. The protrusion of the measuring head is in contact with the lower piezoelectric film.

[0007] Further, the diameter of the upper piezoelectric film is the same as the diameter of the cross-section of the housing.

[0008] Further, the diameter of the first receiving hole is smaller than the diameter of the second receiving hole.

[0009] Further, after the snap ring is installed in the snap ring groove, it extends into the internal space of the second receiving hole.

[0010] Further, the upper piezoelectric film is located in the upper end of the through hole. The through hole is in a stepped shape. The through hole includes a first through hole and a second through hole communicating with the first through hole and located below the first through hole. The inner diameter of the first through hole is larger than the inner diameter of the second through hole.

[0011] Further, the area corresponding to the rubber washer in the position around the spherical protrusion at the upper end of the measuring head is in contact with the rubber washer.

[0012] Further, the upper piezoelectric film and the lower piezoelectric film are made of the same material. A wire is led out from each of the upper piezoelectric film and the lower piezoelectric film.

[0013] Further, the housing and the limiting block are made of aluminum, and the thin plate and the measuring head are prepared from phosphor bronze.

[0014] The present invention also adopts the following technical solution: a measurement method for a piezoelectric sensing device for measuring the backfat thickness of pigs, the steps are as follows:

[0015] Step 1: The measurement personnel first place the piezoelectric sensing device at the measurement position P2 on the pig's backfat, and P2 is the part where the pig's backfat contacts the piezoelectric sensing device;

[0016] Step 2: The measurement personnel then apply a pressure P from point P1 above the piezoelectric sensing device, and this pressure P will directly act on the piezoelectric sensing device. The pressure P will first cause the upper piezoelectric film to deform. According to the piezoelectric effect of the piezoelectric film, the upper piezoelectric film will output a response voltage value V1;

[0017] Step 3: The pressure P will then act on the pig. The backfat in contact with the outer shell will sink downward, and the backfat in the middle part of the outer shell will bulge upward relatively, thereby applying an upward force to the measuring head. The measuring head moves upward and then causes the lower piezoelectric film to deform, and the lower piezoelectric film will generate a response voltage value V2;

[0018] Step 4: After processing the above two response voltage values, the corresponding backfat thickness can be obtained.

[0019] Further, step 4 is specifically: there is a linear relationship between the ratio of the response voltage values V2 and V1 of the two piezoelectric films and the backfat thickness, and the linear relationship is: y = 0.06373 + 0.07346x - 8.07656×10 -4 x 2 -7.62527×10 -6 x 3 , where x is the backfat thickness and y is V2 / V1.

[0020] The present invention has the following beneficial effects:

[0021] (1) The piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention innovatively uses the characteristics of piezoelectric materials to measure the backfat thickness. It has few components, is simple to manufacture, has the characteristics of small volume and low cost, solves the problems of large volume and high price of existing backfat measurement devices, is convenient for measurement personnel to carry and use, and can reduce the breeding cost of farmers.

[0022] (2) The piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention is easy to operate, solves the problem that measurement personnel need to be trained for a long time before they can operate the measurement device, and can provide convenience for the majority of farmers.

[0023] (3) The piezoelectric sensing device and measurement method for measuring the backfat thickness of pigs provided by the present invention have the characteristics of small stimulation to pigs and can effectively reduce pig stress compared with the existing backfat measurement devices and methods. Description of the Drawings:

[0024] Figure 1 It is a schematic diagram of the piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention.

[0025] Figure 2 is Figure 1 Cross-sectional structure schematic diagram of.

[0026] Figure 3 It is a cross-sectional view of the piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention.

[0027] Figure 4 It is a graph showing the relationship between the response voltage value of the lower piezoelectric film and the backfat thickness of the piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention under different pressures P.

[0028] Figure 5 It is a graph showing the relationship between the ratio of the response voltage values V1 and V2 of two piezoelectric films and the backfat thickness of the piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention under different pressures P. Detailed Embodiments:

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figures 1 to 3 As shown, the piezoelectric sensing device for measuring the backfat thickness of pigs of the present invention includes an upper piezoelectric film 1, a housing 2, a thin plate 3, a lower piezoelectric film 4, a rubber washer 5, a measuring head 6, a limiting block 7, and a snap ring 8. The housing 2 is in a cylindrical shape, and a first circular groove 20 is formed by a depression at the middle position of the upper end of the housing 2. The upper piezoelectric film 1 is a circular plate, and the diameter of the upper piezoelectric film 1 is the same as the diameter of the cross-section of the housing 2 so that the upper piezoelectric film 1 can completely cover the first circular groove 20.

[0031] A circular receiving hole 21 extending from top to bottom is formed inside the housing 2. The circular receiving hole 21 includes a first receiving hole 210 and a second receiving hole 211 that is connected to the first receiving hole 210 and is located below the first receiving hole 210. The diameter of the first receiving hole 210 is smaller than the diameter of the second receiving hole 211.

[0032] The thin plate 3 is installed at the upper end of the second receiving hole 211 and adjacent to the first receiving hole 210. A second circular groove 31 is formed by recessing the middle position of the lower end of the thin plate 3. The lower piezoelectric film 4 is pasted at the middle position of the thin plate 3. The lower piezoelectric film 4 is a circular plate body, and the diameter of the lower piezoelectric film 4 is larger than the diameter of the cross-section of the second circular groove 31 so that the lower piezoelectric film 4 can completely cover the second circular groove 31. By providing the first circular groove 20 and the second circular groove 31, the deformation of the upper piezoelectric film 1 and the lower piezoelectric film 4 is facilitated.

[0033] Rubber gaskets 5 are pasted at the positions around the lower piezoelectric film 4 on the thin plate 3.

[0034] A snap ring groove (not labeled) for installing the snap ring 8 is formed by recessing the inner side wall of the second receiving hole 211. After the snap ring 8 is installed in the snap ring groove, it extends into the inner space of the second receiving hole 211.

[0035] The limiting block 7 is clamped between the thin plate 3 and the snap ring 8, and the limiting block 7 is in close contact with the thin plate 3.

[0036] A through hole 70 penetrating through the upper and lower side walls of the limiting block 7 is formed inside the limiting block 7. The through hole 70 is stepped. The through hole 70 includes a first through hole and a second through hole located below the first through hole and communicating with the first through hole. The inner diameter of the first through hole is larger than the inner diameter of the second through hole.

[0037] The upper piezoelectric film 1 is located in the upper end of the through hole 70. A spherical protrusion 60 is formed at the center position of the upper end of the measuring head 6. The spherical protrusion 60 is coated with an insulating material. The measuring head 6 is installed in the through hole 70. The lower end of the measuring head 6 extends beyond the lower end of the limiting block 7 and then into the second receiving hole 211. The protrusion 60 of the measuring head 6 is in contact with the lower piezoelectric film 4. The area corresponding to the rubber gasket 5 at the position around the spherical protrusion 60 at the upper end of the measuring head 6 is in contact with the rubber gasket 5.

[0038] The upper piezoelectric film 1 and the lower piezoelectric film 4 are made of the same material, and a wire is led out from each of the upper piezoelectric film 1 and the lower piezoelectric film 4.

[0039] The housing 2 and the limiting block 7 are made of aluminum, and the thin plate 3 and the measuring head 6 are made of phosphor bronze.

[0040] The piezoelectric sensing device for measuring the backfat thickness of pigs in the present invention has an overall centrosymmetric structure. Among them, the upper piezoelectric film 1, the housing 2, the thin plate 3, the lower piezoelectric film 4, the rubber gasket 5, the measuring head 6, the limiting block 7 and the snap ring 8 are all coaxially installed.

[0041] The piezoelectric sensing device of the present invention is used for measuring the backfat thickness of pigs. The specific design dimensions and materials can be referred to as follows: For example, the diameter D of the upper piezoelectric film 1 is 30 mm, the diameter D of the lower piezoelectric film 2 is 8 mm. The materials of the two parts of the piezoelectric film are the same, the thickness t is 50 μm, and the piezoelectric coefficient d 33 = 180×10 -12 C / N. The outer diameter D of the housing 2 is 30 mm, the height h is 40 mm. The diameter D of the first circular groove at its upper end is 25 mm, and the depth h is 1 mm. The diameter D of the first receiving hole 210 inside is 20 mm, and the depth h is 25 mm. The diameter D of the second receiving hole 211 is 24 mm, and the depth h is 17 mm. The diameter D of the snap ring groove is 26 mm, and the depth h is 1.3 mm. The distance from the bottom of the snap ring groove to the bottom of the housing 2 is L = 10 mm. The diameter D of the thin plate 3 is 24 mm, and the thickness t is 1.5 mm. The diameter D of the second circular groove below the thin plate 3 is 4 mm, and the depth h is 1 mm. The outer diameter D of the limiting block 7 is 24 mm, and the height h is 10 mm. The inner diameter D of the first through hole of the limiting block 7 is 13.5 mm, and the depth h is 8 mm. The inner diameter D of the second through hole of the limiting block 7 is 4 mm, and the depth h is 2 mm. The outer diameter D of the measuring head 6 is 13 mm, and the diameter D of the part of the measuring head 6 extending beyond the limiting block 7 is 4 mm. The diameter D of the rubber washer is 12 mm, and the thickness t is 2 mm. The snap ring is an A standard hole-type elastic retaining ring suitable for a hole diameter of 26 mm. The materials of the housing 2 and the limiting block 7 are aluminum. The thin plate 3 and the measuring head 6 are both made of phosphor bronze material with better elastic performance. The material of the piezoelectric film is flexible PVDF piezoelectric film.

[0042] The measuring method of the piezoelectric sensing device of the present invention for measuring the backfat thickness of pigs is as follows:

[0043] Step 1: The measuring personnel first place the piezoelectric sensing device at the measuring position P2 on the pig backfat 9 (the P2 point is the part where the pig backfat 9 contacts the piezoelectric sensing device);

[0044] Step 2: Then the measuring personnel apply a pressure P from the P1 point above the piezoelectric sensing device. This pressure P will directly act on the piezoelectric sensing device. The pressure P will first cause the upper piezoelectric film 1 to deform. According to the piezoelectric effect of the piezoelectric film, the upper piezoelectric film 1 will output a response voltage value V1;

[0045] Step 3: Next, the pressure P will act on the pig. The pig backfat 9 in contact with the housing 2 will sink downward, while the pig backfat 9 in the middle part of the housing 2 will bulge upward relatively, thereby applying an upward force to the measuring head 6. The measuring head 6 moves upward and then causes the lower piezoelectric film 4 to deform. The lower piezoelectric film 4 will generate a response voltage value V2;

[0046] Step 4: After processing the above two response voltage values, the corresponding backfat thickness can be obtained.

[0047] Refer to Figures 4 to 5 as shown in Figure 4 which is the relationship between the response voltage values of the two piezoelectric films of the piezoelectric sensing device provided by the present invention and the backfat thickness. Figure 4 In Figure 4 , the abscissa represents the backfat thickness, and the ordinate represents the response signal V2 of the lower piezoelectric film under different pressures P. As can be seen from

[0048] 1) When P1 = 1000 Pa, the response voltage value of the upper piezoelectric film is 0.34 V;

[0049] 2) When P2 = 2000 Pa, the response voltage value of the upper piezoelectric film is 0.68 V;

[0050] 3) When P3 = 5000 Pa, the response voltage value of the upper piezoelectric film is 1.70 V;

[0051] 4) When P4 = 10000 Pa, the response voltage value of the upper piezoelectric film is 3.40 V.

[0052] Figure 5 which is the relationship between the ratio of the response voltage values V2 and V1 of the two piezoelectric films of the device provided by the present invention under different pressures P and the backfat thickness. Figure 5 In Figure 5 , the abscissa represents the backfat thickness, and the ordinate represents the ratio of the response voltage values V2 and V1 of the two piezoelectric films under different pressures P. As can be seen from -4 x 2 -7.62527×10 -6 x 3 , where x is the backfat thickness and y is V2 / V1.

[0053] The piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention can effectively reduce the stress of pigs caused by external stimuli through an efficient and convenient backfat measurement method. At the same time, the current backfat measurement methods mainly use backfat calipers or ultrasonic detection techniques, which are costly, complex to operate, and low in efficiency. Therefore, the piezoelectric sensing device for measuring the backfat thickness of pigs provided by the present invention has the advantages of simple structure, low manufacturing cost, easy to carry, and simple operation, and can effectively improve the measurement efficiency and reduce the stress response of pigs.

[0054] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A measuring method of a piezoelectric sensing device for measuring the backfat thickness of pigs, wherein the piezoelectric sensing device for measuring the backfat thickness of pigs includes an upper piezoelectric film (1), a housing (2), a thin plate (3), a lower piezoelectric film (4), a rubber gasket (5), a measuring head (6), a limiting block (7), and a snap ring (8). The housing (2) is in a cylindrical shape. A first circular groove (20) is formed by a depression at the middle position of the upper end of the housing (2). The upper piezoelectric film (1) is a circular plate body and completely covers the first circular groove (20). A circular receiving hole (21) extending from top to bottom is formed inside the housing (2). The circular receiving hole (21) includes a first receiving hole (210) and a second receiving hole (211) that is connected to the first receiving hole (210) and is located below the first receiving hole (210). The thin plate (3) is installed at the upper end of the second receiving hole (211) and adjacent to the position of the first receiving hole (210). A second circular groove (31) is formed by a depression at the middle position of the lower end of the thin plate (3). The lower piezoelectric film (4) is pasted at the middle position of the thin plate (3). The lower piezoelectric film (4) is a circular plate body and completely covers the second circular groove (31). Rubber gaskets (5) are pasted at the positions around the lower piezoelectric film (4) on the thin plate (3). A snap ring groove for installing the snap ring (8) is formed by a depression on the inner side wall of the second receiving hole (211). The limiting block (7) is clamped between the thin plate (3) and the snap ring (8). The limiting block (7) is in close contact with the thin plate (3). A through hole (70) penetrating through the upper and lower side walls of the limiting block (7) is formed inside the limiting block (7). A spherical protrusion (60) is formed at the center position of the upper end of the measuring head (6). The spherical protrusion (60) is coated with an insulating material. The measuring head (6) is installed in the through hole (70). The lower end of the measuring head (6) extends into the second receiving hole (211) after exceeding the lower end of the limiting block (7). The protrusion (60) of the measuring head (6) is in contact with the lower piezoelectric film (4). It is characterized in that: The steps are as follows: Step 1: The measuring personnel first place the piezoelectric sensing device at the measurement position P2 on the back fat of the pig (9), and the P2 point is the part where the back fat of the pig (9) contacts the piezoelectric sensing device; Step 2. The surveyor then applies a pressure from point P1 above the piezoelectric sensing device. P , and this pressure P will act directly on the piezoelectric sensing device. The pressure P will first cause the upper piezoelectric film (1) to deform. According to the piezoelectric effect of the piezoelectric film, the upper piezoelectric film (1) will output a response voltage value V1. Step 3: Pressure P Secondly, it acts on the pig. The back fat (9) of the pig in contact with the outer shell (2) will sink downward, while the back fat (9) in the middle part of the outer shell (2) will bulge upward relatively, thereby applying an upward force to the measuring head (6). The measuring head (6) moves upward, causing the lower piezoelectric film (4) to deform. The lower piezoelectric film (4) will generate a response voltage value V2; Step 4: After processing the above two response voltage values, the corresponding back fat thickness can be obtained.

2. The measuring method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: The diameter of the upper piezoelectric film (1) is the same as the diameter of the cross-section of the outer shell (2).

3. The measuring method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: The diameter of the first receiving hole (210) is smaller than the diameter of the second receiving hole (211).

4. The measuring method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: After the snap ring (8) is installed in the snap ring groove, it extends into the internal space of the second receiving hole (211).

5. The measuring method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: The upper piezoelectric film (1) is located in the upper end of the through hole (70). The through hole (70) is stepped. The through hole (70) includes a first through hole and a second through hole that is in communication with the first through hole and is located below the first through hole. The inner diameter of the first through hole is larger than the inner diameter of the second through hole.

6. The measurement method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: The upper end of the measuring head (6) is in contact with the rubber washer (5) in the area corresponding to the rubber washer (5) around the spherical protrusion (60).

7. The measuring method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: The upper piezoelectric film (1) and the lower piezoelectric film (4) are made of the same material, and a wire is led out from each of the upper piezoelectric film (1) and the lower piezoelectric film (4).

8. The measuring method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: The outer shell (2) and the limit block (7) are made of aluminum, and the thin plate (3) and the measuring head (6) are made of phosphor bronze.

9. The measuring method of the piezoelectric sensing device for measuring the backfat thickness of pigs according to claim 1, characterized in that: Step 4 is specifically as follows: The ratio of the response voltage values V2 and V1 of the two piezoelectric films has a linear relationship with the backfat thickness, and the linear relationship is: y = 0.06373 + 0.07346 x - 8.07656×10 -4 x 2 - 7.62527×10 -6 x 3 , where x is the backfat thickness, y is V2∕V 1。

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