Feces residue cleaning structure for manure collection pool of pig farm

Abstract

The utility model relates to the technical field of livestock breeding in pig farms, in particular to a manure residue cleaning structure for a manure collecting pit of a pig farm, which comprises a fall well arranged at the tail end of a secondary manure scraping channel at the bottom layer of the pig farm; all the fall wells converge into a valve well, and a gate valve unit is arranged in the valve well; one side, far away from the fall well, of the valve well is communicated with a filter well, a settling pond and a grillage machine pond through a sewage pipe, and the water outlet end of the grillage machine pond is communicated with a manure collecting pond. Meanwhile, the failure rate and maintenance cost of the pump are effectively reduced, the production efficiency of a pig farm is improved, and the pig raising cost is reduced. The novel manure collection pool manure residue cleaning structure is suitable for improvement of an existing pig farm, is also suitable for being popularized and used in a newly-built pig farm, and has reliable applicability and wide market prospects.

Description

Technical Field

[0001] The utility model relates to the technical field of animal husbandry, in particular to a manure residue cleaning structure for a manure collecting pool in a pig farm. Background Art

[0002] At present, many pig farms in southern China that were built five years ago use a mechanical scraping system for manure removal in the pig house, and a manure collection tank pumping system outside the pig house. A manure collection tank with an effective volume of 100-200 cubic meters is set up outside each pig house, and then a sewage pump is used to pump the manure to the sewage treatment plant. However, this manure collection tank pumping system has many problems in actual use. First, when repairing equipment in the outdoor manure collection tank and cleaning garbage sediment in the tank, part of the manure in the manure duct will flow into the manure collection tank, causing workers to need to clean it in a harsh working environment, posing a safety hazard. Secondly, the floating garbage in the manure collection tank is manually cleaned with a net bag, which is labor-intensive for workers and difficult to clean up, and it is very easy to cause pump jams.

[0003] In addition, the mud and sand that sink to the bottom of the manure collection pit and small iron parts such as screws, bolts, screwdrivers, and needles cannot be cleaned up, and these small iron parts are very easy to jam the pump. It is difficult to clean up the soft garbage such as feces, pig hair, and plastic bags in the manure collection pit by manual cleaning, and these soft garbage are most likely to jam the pump. Because feces and pig hair are lighter than manure water, they float on the surface of manure water and separate from manure water. The pump first pumps manure water, and the mixed water of feces and pig hair that is pumped later is difficult to pump, and pump jams often occur.

[0004] After the pig farm was in operation for two years, the feces in the manure collection tank had precipitated crystal stones up to 1 meter high, which was extremely difficult to clean. It could not be removed without the use of special tools such as electric picks. The workers had low cleaning efficiency and long working hours, which posed a safety hazard. The feces, feces, mud and sand in the manure collection tank flowed directly into the pump pit. The small iron parts and feces that flowed in with the feces could easily cause the pump to get stuck. These problems increased the cost of cleaning up garbage and equipment maintenance, increased the labor intensity of workers, and posed a certain safety hazard.

[0005] What is more serious is that when the manure discharge in the pig house is suspended in order to repair equipment or clean up garbage, the pig manure will ferment in the pig house for too long and produce a lot of odor. The odor not only affects the healthy growth of pigs, but also increases the COD index of pig manure, increases the pressure on sewage treatment plants, and ultimately affects the production and benefits of the pig farm. Utility Model Content

[0006] The utility model aims to solve the above-mentioned shortcomings in the prior art and proposes a manure residue cleaning structure for a manure collecting pool in a pig farm.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] Design a pig farm manure pool manure cleaning structure, including:

[0009] A drop well is set at the end of the secondary manure scraping channel on the bottom floor of the pig house;

[0010] Each of the drop wells converges into a valve well, and a gate valve unit is provided in the valve well;

[0011] The side of the valve well away from the drop well is connected to a filter well, a sedimentation tank and a screen machine pool through a sewage pipe, and the water outlet of the screen machine pool is connected to a manure collecting tank, wherein a stirring device is arranged inside the manure collecting tank.

[0012] Furthermore, the gate valve unit is a manual gate valve, and the moving part of the manual gate valve is used to intercept the sewage pipe between the drop well and the valve well.

[0013] Furthermore, a first salvaging component is disposed inside the filter well, and a second salvaging component is disposed inside the sedimentation tank, wherein the filter well and the sedimentation tank are separated by a filter mesh plate.

[0014] Furthermore, a gantry crane is provided above the filter well and the sedimentation tank. The gantry crane moves along a predetermined direction on the well surface. The gantry crane is used to lift and salvage the first salvage component and the second salvage component.

[0015] Furthermore, the first salvaging component comprises a box-shaped structure formed by welding a plurality of ribs in the transverse and longitudinal directions, and triangular hangers are fixedly mounted on both sides of the top of the box-shaped structure.

[0016] Furthermore, the second salvaging component includes a filter box and a reinforcing bone fixed to the outside of the filter box, and a triangular hanger is also fixed above the reinforcing bone.

[0017] Furthermore, a screen machine is installed inside the screen machine pool, and the screen machine pool is connected to the manure collecting tank through a secret passage, wherein the secret passage has a predetermined slope.

[0018] Furthermore, the stirring device includes a motor fixed on the top of the manure collecting pit, and a stirring paddle is fixedly installed on the shaft end of the motor, and the stirring paddle is located inside the manure collecting pit.

[0019] Furthermore, three slopes are formed inside the manure collecting pit, which are connected in sequence and whose width decreases downwards. The three slopes form a U-shaped funnel structure, wherein the opposite surfaces of the three slopes in the manure collecting pit are vertical surfaces, and smooth parts are arranged on the slopes.

[0020] Furthermore, a pump pit is provided inside the manure collecting pit, the pump pit is located between the bottoms of the three inclined surfaces, and a sewage pump is installed inside the pump pit, wherein a U-shaped blocking groove is provided above the pump pit, the U-shaped blocking groove is located between the bottoms of the three inclined surfaces.

[0021] The utility model proposes a manure collection tank manure residue cleaning structure for a pig farm, which has the beneficial effects of significantly improving the working environment of maintenance personnel in the pig farm and reducing the work intensity, so that maintenance personnel can work with peace of mind, while effectively reducing the failure rate and maintenance cost of the pump, improving the production efficiency of the pig farm, and reducing the cost of pig farming. The new manure collection tank manure residue cleaning structure is suitable for the transformation of existing pig farms and is also suitable for promotion and use in newly built pig farms, and has reliable applicability and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the utility model;

[0023] Figure 2 This is a schematic diagram of the valve well structure of the utility model;

[0024] Figure 3 This is a schematic diagram of the gantry crane structure of the utility model;

[0025] Figure 4 This is a front view of the first salvage component of the utility model;

[0026] Figure 5 It is a side view of the first salvage component of the utility model;

[0027] Figure 6 It is a side view of the second salvage component of the utility model;

[0028] Figure 7 It is a bottom view of the second salvage component of the utility model;

[0029] Figure 8 This is a schematic diagram of the filter screen structure of the utility model;

[0030] Fig. 9 This is a schematic diagram of the structure of a manure collecting tank of the utility model;

[0031] Fig.10 It is a top view of the manure collecting tank of the present utility model.

[0032] In the figure: 1. drop shaft; 10. sewage pipe; 2. valve shaft; 3. gate valve unit; 4. filter shaft; 41. first salvage component; 42. filter screen plate; 5. sedimentation tank; 51. second salvage component; 6. screen machine pool; 61. screen machine; 62. secret passage; 7. manure collection tank; 71. stirring device; 72. inclined plane; 73. pump pit; 74. sewage pump; 75. U-shaped blocking groove; 8. gantry crane. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0034] Reference Figure 1-10 This is an embodiment of the utility model, which discloses a manure residue cleaning structure for a manure collecting pool in a pig farm. Specifically, the cleaning structure includes a drop well 1 arranged at the end of a secondary manure scraping channel at the bottom of a pig house; specifically, each drop well 1 converges into a valve well 2, and a gate valve unit 3 is arranged in the valve well 2;

[0035] The side of the valve well 2 away from the drop well 1 is connected to a filter well 4, a sedimentation tank 5 and a screen tank 6 through a sewage pipe 10, and the water outlet of the screen tank 6 is connected to a manure collecting tank 7, wherein a stirring device 71 is arranged inside the manure collecting tank 7.

[0036] Furthermore, since the current pig farm uses a manure pumping system for the manure collecting tank 7, when cleaning the sediment in the manure collecting tank and repairing the equipment, even if the manure scraper is stopped from discharging manure, manure will still flow into the manure inlet of the manure collecting tank 7. The reason is that part of the manure in the pig house will flow into the manure collecting tank 7 under the action of gravity. When workers work in the manure collecting tank, they usually wear waders, but they will still be splashed with manure. The working environment is poor and the ammonia is strong. This leads to complaints and resistance from the workers, seriously affecting the normal maintenance of the pig farm's manure discharge equipment.

[0037] Based on this problem, in this embodiment, a gate valve unit 3 is used to close the sewage pipeline. Specifically, the gate valve unit 3 is a manual gate valve. The moving part of the manual gate valve is used to intercept the sewage pipe 10 between the drop well 1 and the valve well 2. In this embodiment, the valve well size is 1200mm long, 800mm wide, and 1500mm deep. The sewage pipe 10 and the manual gate valve both use a pipe diameter of 400mm. When it is necessary to clean the sediment in the manure collection tank 7 or repair the equipment, all the manure discharge systems in the pig house will be closed and the gate valve will be closed at the same time. In this way, the secondary manure scraping channel space (1000mm wide, 800mm deep, and 50 meters long) at the front end of the gate valve can be used as temporary storage, and the drop well space of 1200mmx1000mmx800mm can also be used, with a volume of 0.96m 3, and the buried 1.9-meter-long, 400-mm-diameter PVC sewage pipe space, with a volume of 0.24m 3 In total, these spaces have a total volume of 11.2m 3 , which is enough to store the self-flowing manure volume of a 5-story pig house within 4 hours. In this way, workers can work safely in the manure collection tank within 4 hours, which improves the working environment, improves work efficiency, reduces maintenance difficulty, and ensures the normal operation of the pig farm.

[0038] In some embodiments, a first salvage component 41 is disposed inside the filter well 4 of the utility model, and a second salvage component 51 is disposed inside the sedimentation tank 5, wherein the filter well 4 and the sedimentation tank 5 are separated by a filter screen 42.

[0039] In addition, based on the above embodiment, a gantry crane 8 is further provided above the filtration well 4 and the sedimentation tank 5 . The gantry crane 8 moves along a predetermined direction on the well surface. The gantry crane 8 is used to lift and salvage the first salvage component 41 and the second salvage component 51 .

[0040] Specifically, during the breeding and maintenance of the pig house, various items may accidentally fall into the primary scraping channel, including towels, plastic parts, vas deferens, infusion tubes, fence steel bar latches, tools, etc. In addition, workers will pour large garbage that cannot pass through the slatted plate, such as dry feces, pig hair balls, woven bags and broom heads, into the primary scraping channel from the inspection port. These large garbage will be scraped into the feces bucket by the scraping trolley along with the feces water, and then fall into the secondary scraping channel through the riser, and finally scraped into the drop well and flow into the outdoor manure collection pool 7 through a pipe with a diameter of 400mm.

[0041] In the manure collecting tank 7, these large garbage need to be manually cleaned through a net bag, which is a labor-intensive job. Since most of the top plate of the manure collecting tank 7 is a reinforced concrete structure, there are only 1-2 1000mmx1000mm inspection ports, which makes it very difficult to clean the garbage floating under the top plate. The iron parts and mud and sand that sink to the bottom cannot be cleaned. These uncleaned garbage will gradually precipitate and crystallize. The sedimentation height may reach 1 meter within two years, seriously affecting the collection function of the manure collecting tank. Too much feces will flow into the pump pit and fill the pump pit, causing the sewage pump to fail to work. At the same time, uncleaned large garbage and iron parts are also prone to cause pump blockage.

[0042] In order to solve the above problems, in the embodiment of the utility model, the first salvage component 41 includes a box-like structure formed by welding a plurality of ribs in the transverse and longitudinal directions, and triangular hangers are fixedly installed on both sides of the top of the box-like structure. That is, in order to prevent large garbage and large iron pieces from entering the manure collecting tank in this embodiment, the pig farm has designed a drop-type sedimentation tank 5, which is equipped with a stainless steel filter screen 42 for filtering large garbage, and a first salvage component made of stainless steel bars for collecting large iron pieces. The dimensions of the sedimentation tank 5 are 1000 mm long, 800 mm wide, and 1600 mm deep, and the bottom plate is 200 mm lower than the bottom of the front sewage pipe 10.

[0043] The filter screen plate 42 is welded from stainless steel bars with a diameter of 10 mm, with dimensions of 750 mm wide, 1600 mm high, and a grid spacing of 50 mm x 200 mm. The first salvage component is also welded from the same stainless steel bars, with dimensions of 960 mm long, 760 mm wide, 150 mm high, and a grid spacing of 50 mm x 200 mm. The head and tail surfaces of the first salvage component 41 have triangular hangers welded from stainless steel bars with a diameter of 10 mm, which are used as the hook hanging points of the gantry crane 8.

[0044] In order to lift the first salvage component 41, two motors need to work in conjunction to ensure balance. Before lifting the first salvage component 41, close the manual gate valve at the front end to let the manure in the pool flow away so as to expose the lifting point of the salvage component. Then, use the two hooks of the gantry crane 8 to hook the lifting points at the head and tail of the first salvage component 41 respectively, lift the first salvage component 41 to the well surface, and at the same time load the large garbage in the well into the first salvage component 41, then move the first salvage component 41 to the ground of the garbage dump through the horizontal track, and pour the garbage in the first salvage component 41 into a special garbage bin. Workers clean up the salvage component garbage once a week and transport the collected garbage to the sewage treatment plant every month.

[0045] Furthermore, currently, a manure scraper is used for mechanical manure cleaning. Fine stone concrete or cement mortar is usually used for the leveling layer of the manure channel in the pig house. The floating slurry layer on the surface of these materials will be scraped off under the long-term scraping of the manure scraper. These scraped sand and cement powders will flow into the manure collecting tank 7 along with the manure, mix with the sticky manure residue, gradually precipitate and crystallize into stones at the bottom of the tank. After about 2 years, the sediment in the manure collecting tank 7 can accumulate to 1 meter high. At this time, the sewage pump cannot work normally, affecting the normal production of the pig farm. These sediments need to be cleaned manually, but because the space is semi-enclosed and the ammonia is strong, the cleaning work is very difficult. In addition, small iron parts such as fallen screw heads and screws may also flow into the manure collecting tank 7 with the manure, which may cause the sewage pump to get stuck and affect the normal discharge of manure.

[0046] Therefore, in order to solve this problem, the second salvage component 51 in this embodiment includes a filter box and a reinforcement bone fixed to the outside of the filter box, and a triangular hanger is also fixed above the reinforcement bone, that is, in this embodiment, a sedimentation tank with a depth of 200 meters is designed at the front end of the pig farm manure collection pool, and the sedimentation tank is 1000 meters long, 800 meters wide, and 1800 meters deep. A second salvage component is placed at the bottom to collect small iron parts and mud and sand. The second salvage component is welded by stainless steel square tubes and punching plates, and its dimensions are 960 meters long, 760 meters wide, and 150 meters high. The lifting and horizontal movement operations of the second salvage component 51 are completed by the gantry crane 8, and the second salvage component 51 of the sedimentation tank and the filter drop well share an electric driving structure. When the second salvage component 51 is lifted, the small garbage in the well will be loaded into the assembly at the same time, and then the assembly will be moved to the ground of the garbage dump through the horizontal track, and the small garbage and mud and sand in the assembly will be loaded into woven bags and neatly stacked. Workers clean the mud and sand from the second salvaged part once a week, and the collected mud and sand are transported to the sewage treatment plant by car every month. This design can prevent most of the mud and sand and small iron pieces from entering the manure collection tank, avoid the occurrence of small iron pieces getting stuck in the pump, improve work efficiency, reduce the labor intensity of workers, and provide better protection for the normal operation of the back-end garbage cleaning equipment and manure pumping equipment.

[0047] In some embodiments, in the present invention, in order to prevent soft garbage such as feces, pig hair, small bags of medicine, earrings, ropes, etc. from entering the manure collecting tank 7 and causing the pump to get stuck, a screen machine 61 is installed inside the screen machine pool 6, and the screen machine pool 6 is connected to the manure collecting tank 7 through a dark passage 62, wherein the dark passage 62 has a predetermined slope, and the feces is filtered by the screen machine 61 and flows into the dark passage 62 with a length of 3550, a width of 1200, and a height of 1400-1600, and then flows into the manure collecting tank 7. A width of 100 is designed on the partition wall at the back of the screen machine 61. The outlet hole is 1200 high and 1300 high. The floor slope of the secret passage 62 of the screen machine 61 is 4.88%. This slope does not affect the flow rate of the fecal water. The fecal residue balls, pig hair balls, small medicine bags, earrings, ropes and other soft garbage in the fecal water are cleaned through the screen machine 61 to avoid pump jam. At the same time, the ground behind the slag outlet of the screen machine 61 needs to be hardened and surrounded by a 200 wide and 200 high brick wall to collect the garbage filtered out by the screen machine 61. The garbage is collected by a bucket truck every week and poured into a special garbage bin, and transported to the sewage treatment plant by a car every month.

[0048] Furthermore, in order to solve the problem that the feces and feces are separated and the sewage pump cannot pump out the feces completely, and the feces precipitated crystal stones are difficult to clean, the stirring device 71 in this embodiment includes a motor fixed on the top of the manure collecting tank 7, and a stirring paddle is fixedly installed on the shaft end of the motor. The stirring paddle is located inside the manure collecting tank 7. In order to facilitate the installation and maintenance of the stirring device 71, an inspection port and an observation port are designed at the pump pit and the manure inlet, and the size is 1400X3000. The stirring device 71 not only mixes the floating feces and pig hair with the manure, but also breaks up the feces and pig hair balls through stirring, so that the manure is more uniform and fluid. Such manure not only does not get stuck in the pump, but also makes it easier to pump out the manure. The bottom of the pool is designed to be a funnel-shaped bottom plate, and the remaining residual manure flows into the pump pit and is pumped out. The modified manure collecting tank 7 truly pumps out all the manure.

[0049] On the basis of the above-mentioned embodiments, in order to solve the problem that the sedimentation and crystallization of mud, sand and feces are difficult to clean, in the embodiment of the utility model, three slopes 72 are formed in sequence inside the manure collecting tank 7, and the width decreases downward. The three slopes 72 form a U-shaped funnel structure, wherein the opposite surfaces of the three slopes 72 in the manure collecting tank 7 are vertical surfaces, and smooth parts are provided on the slopes 72, and the smooth parts are attached tiles. The slopes of the three sides are designed to be greater than 13%. In order to improve the smoothness of the bottom plate slope 72, the three bottom plate slopes 72 are all covered with smooth tiles. Such a design completely solves the problem that the manure water in the manure collecting tank cannot be pumped out cleanly. After being pumped out, the manure water will flow into the sewage pump pit along the large slope. There will be almost no manure residue left on the bottom plate of the manure collecting tank 7, and the problem of manure residue precipitation and crystallization of stones and the work of sending people to clean up the manure residue will no longer occur.

[0050] Furthermore, in order to solve the problem that the front sedimentation tank is full and not cleaned in time, and some small screws flow into the manure collecting tank and cause the pump to get stuck, a pump pit 73 is provided inside the manure collecting tank 7, and the pump pit 73 is located between the bottoms of the three inclined surfaces 72, and a sewage pump 74 is installed therein, wherein a U-shaped blocking groove 75 is provided above the pump pit 73, and the U-shaped blocking groove 75 is located between the bottoms of the three inclined surfaces 72. The specific pump pit is 1000 lower than the bottom plate of the manure collecting tank, the pump pit is 1200 long, 1000 wide and 1000 deep, and a U-shaped blocking groove 75 with a depth of 200 and a width of 200 is designed around the pump pit 73. The U-shaped blocking groove 75 is an additional insurance to avoid pump jams, and plays a role in protecting the sewage pump again, making the design of the manure collecting tank 7 more perfect. Individual small screws that flow into the manure collecting tank 7 will only flow into the sedimentation tank, and will not flow into the pump pit 73 to jam the pump. The small screws in the U-shaped blocking groove 75 do not need to be cleaned manually. Workers only need to operate on the top plate of the manure collecting tank 7. The operation is very simple. Every year, workers only need to stand by the guardrail of the inspection port and use a strong magnet with a rope to put it down into the U-shaped blocking groove 75, walk a few circles and pull it up. Through this operation, all small screws in the groove will be attracted and removed by the strong magnet. This type of design not only reduces the maintenance and cost of the sewage pump, but also extends the service life of the pump, thereby maximizing the normal production of the pig farm.

[0051] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A manure residue cleaning structure for a pig farm manure collection pool, characterized in that: include: A drop well (1) is arranged at the end of the secondary manure scraping channel on the bottom floor of the pig house; Each of the drop wells (1) converges into a valve well (2), and a gate valve unit (3) is provided in the valve well (2); The side of the valve well (2) away from the drop well (1) is connected to a filter well (4), a sedimentation tank (5) and a screen tank (6) through a sewage pipe (10); the water outlet of the screen tank (6) is connected to a manure collecting tank (7), wherein a stirring device (71) is provided inside the manure collecting tank (7).

2. The manure residue cleaning structure for a pig farm manure collecting pool according to claim 1 is characterized by: The gate valve unit (3) is a manual gate valve, and the movable part of the manual gate valve is used to intercept the sewage pipe (10) between the drop well (1) and the valve well (2).

3. The manure residue cleaning structure for a pig farm manure collecting pool according to claim 1 is characterized by: A first salvaging component (41) is provided inside the filtering well (4), and a second salvaging component (51) is provided inside the sedimentation tank (5), wherein the filtering well (4) and the sedimentation tank (5) are separated by a filtering mesh plate (42).

4. The manure residue cleaning structure for a pig farm manure collecting pool according to claim 3 is characterized by: A gantry crane (8) is also provided above the filtering well (4) and the sedimentation tank (5); the gantry crane (8) moves along a predetermined direction on the well surface; the gantry crane (8) is used to lift and salvage the first salvage component (41) and the second salvage component (51).

5. The manure residue cleaning structure for a pig farm manure collecting pool according to claim 3 is characterized by: The first salvaging component (41) comprises a box-shaped structure formed by welding a plurality of ribs in the transverse and longitudinal directions, and triangular hangers are fixedly mounted on both sides of the top of the box-shaped structure.

6. The manure residue cleaning structure for a pig farm manure collection pool according to claim 3, characterized in that: The second salvaging component (51) comprises a filter box and a reinforcing bone fixed to the outside of the filter box, and a triangular hanger is also fixed above the reinforcing bone.

7. The manure residue cleaning structure for a pig farm manure collecting pool according to claim 1, characterized in that: A screen machine (61) is installed inside the screen machine pool (6), and the screen machine pool (6) is connected to the manure collecting pool (7) through a dark passage (62), wherein the dark passage (62) has a predetermined slope.

8. The manure residue cleaning structure for a pig farm manure collecting pool according to claim 1, characterized in that: The stirring device (71) comprises a motor fixed on the top of the manure collecting pit (7), and a stirring paddle is fixedly mounted on the shaft end of the motor, and the stirring paddle is located inside the manure collecting pit (7).

9. The manure residue cleaning structure for a pig farm manure collection pool according to claim 1, characterized in that: Three slopes (72) are formed inside the manure collecting tank (7), which are connected in sequence and whose widths decrease downwards. The three slopes (72) form a U-shaped funnel structure, wherein the opposite surfaces of the three slopes (72) in the manure collecting tank (7) are vertical surfaces, and smooth parts are arranged on the slopes (72).

10. The manure residue cleaning structure for a pig farm manure collecting pool according to claim 9, characterized in that: A pump pit (73) is provided inside the manure collecting tank (7), the pump pit (73) is located between the bottoms of the three inclined surfaces (72), and a sewage pump (74) is installed inside the pump pit, wherein a U-shaped blocking groove (75) is provided above the pump pit (73), the U-shaped blocking groove (75) is located between the bottoms of the three inclined surfaces (72).

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