A scraper with an external oil pump for a hydraulic system

Abstract

The present invention discloses a scraper with an external oil pump for a hydraulic system, which includes a bulldozing plate assembly, a bucket, a walking swing arm wheel assembly, and a hydraulic control system. The bulldozing plate assembly includes a bulldozing plate, which is placed inside the bucket. A traction frame is connected to the front of the bucket, and a connecting frame is provided at the back of the bucket. The hydraulic control system includes an external pump, and the external pump is connected to the PTO output shaft of the tractor through a coupling. The external pump is used to increase the energy of the hydraulic oil in the depth-limiting cylinder, or the external pump is used to increase the energy of the hydraulic oil in the depth-limiting cylinder and the bulldozing cylinder. The hydraulic components for frequent operation are all external, and the damage repair cost is low. The hydraulic oil used by the tractor is relatively expensive, and the external pump only requires very ordinary hydraulic oil, so the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to a scraper, and more particularly to a scraper with an external oil pump for a hydraulic system. Background Art

[0002] In the prior art, the operation mode of a scraper is to detect the data of the undulation of the ground through satellite, send the digital signal to the receiver installed on the tractor, and the receiver controls the hydraulic system of the tractor according to the received signal to control the lifting of two depth-limiting wheels at the tail and the telescoping of the earth-moving cylinder. When encountering a high ground, the depth-limiting wheels are lifted, and the digging depth of the bucket is adjusted to level the ground; when encountering a low ground, the depth-limiting wheels are lowered, and the earth-moving cylinder in the pit is used to push the soil for landfill. Since the oil circuit has been in a frequent operation situation, it has an impact on the service life of the hydraulic system of the tractor, with high maintenance costs and poor heat dissipation effect. Summary of the Invention

[0003] In order to solve the problems in the prior art that the hydraulic system of the tractor is used to control the depth-limiting cylinder and the earth-moving cylinder of the scraper, resulting in a short service life of the hydraulic system of the tractor and high maintenance costs, the present invention provides a scraper using an external pump, and the specific technical solutions adopted are as follows:

[0004] A scraper with an external oil pump for a hydraulic system includes an earth-moving plate assembly, a bucket, a walking swing arm wheel assembly, and a hydraulic control system. The earth-moving plate assembly includes an earth-moving plate, the earth-moving plate is disposed inside the bucket, a traction frame is connected in front of the bucket, and a connecting frame is provided behind the bucket; the walking swing arm wheel assembly includes a swing arm joint and two depth-limiting wheels connected by the swing arm joint, the walking swing arm wheel group is movably connected to the lower end of the connecting frame, and a group of depth-limiting cylinders are provided between the upper end of the connecting frame and the walking swing arm wheel group; a earth-moving cylinder support for supporting the earth-moving cylinder is further provided on the connecting frame, one end of the earth-moving cylinder is connected to the earth-moving cylinder support, and the other end is connected to the back of the earth-moving plate; the hydraulic control system includes an external pump, and the external pump is connected to the PTO output shaft of the tractor through a coupling; the external pump is used to increase the energy of the hydraulic oil of the depth-limiting cylinder, or the external pump is used to increase the energy of the hydraulic oil of the depth-limiting cylinder and the earth-moving cylinder.

[0005] For the two depth-limiting wheels connected by the same swing arm joint, as one depth-limiting wheel rises, the other depth-limiting wheel drops; as one depth-limiting wheel drops, the other depth-limiting wheel rises.

[0006] Two sets of walking swing arm wheel groups are each connected by a swing arm joint. During operation, when the ground levels where the two sets of tires are located are different, a single set of tires relies on the swing of the swing arm to fit the ground, avoiding the situation where one end is in contact with the ground and the other end is in the air.

[0007] The external pump is a gear pump, which is connected to the PTO output shaft of the tractor through a coupling and is placed at the rear of the tractor.

[0008] When the depth-limiting cylinder is opened, the depth-limiting wheels are lifted, and at the same time, the scraper increases the depth of soil intake; when the depth-limiting cylinder is folded, the depth-limiting wheels return to the ground, and the scraper also returns to the reference plane. Then the bulldozing cylinder is opened, and the bulldozing plate bulldozes the soil to fill in the concave places.

[0009] When the external pump is used to increase the energy of the hydraulic oil of the depth-limiting cylinder, the external pump is synchronously connected to the group of depth-limiting cylinders through an external solenoid valve; the bulldozing cylinder is connected to the solenoid valve on the oil circuit of the tractor.

[0010] Furthermore, the external pump is synchronously connected to the group of depth-limiting cylinders through an external solenoid valve, and an external hydraulic lock is provided between the solenoid valve and the group of depth-limiting cylinders; during the transportation process of the scraper, the depth-limiting cylinders are all opened. At this time, the hydraulic lock is used to disconnect the depth-limiting cylinders from the main oil circuit to prevent accidents during transportation.

[0011] When the external pump is used to increase the energy of the hydraulic oil of the depth-limiting cylinder and the bulldozing cylinder, the external pump is connected to an external solenoid valve with two oil circuits. One oil circuit of the solenoid valve is synchronously connected to the group of depth-limiting cylinders, and the other oil circuit of the solenoid valve is connected to the bulldozing cylinder. Furthermore, an external ball valve is provided on the oil circuit where the solenoid valve is connected to the rodless cavity of the group of depth-limiting cylinders.

[0012] The reference plane is determined through satellite signals, and the undulations of the ground are detected and the signals are transmitted to the solenoid valve at the same time.

[0013] The solenoid valve controls the operation of the hydraulic cylinder: when the soil is higher than the reference plane, the depth-limiting cylinder is opened to increase the depth of soil intake to achieve soil scraping. After the bucket is filled with soil, it is scraped to a place lower than the reference plane, the depth-limiting cylinder is folded, and at the same time, the bulldozing cylinder is opened to achieve bulldozing for filling.

[0014] The hydraulic components for frequent operation are all external, and the damage repair cost is low. The hydraulic oil used by the tractor is relatively expensive, and the external pump only requires very ordinary hydraulic oil, so the maintenance cost is reduced.

[0015] The present invention also provides an external hydraulic oil radiator and an external hydraulic air filter. One end of the hydraulic oil radiator is connected to the oil return port of the solenoid valve, the other end is connected to the hydraulic air filter, and the hydraulic air filter is connected to the fuel tank.

[0016] The hydraulic air filter is used to filter the oil circulating in the hydraulic system and remove impurities; the radiator is used to cool the oil, making the oil more stable and having a longer service life; the hydraulic air filter consists of two parts, an air filter and an oil filling filter, which can not only prevent particulate pollutants from invading the system through the breather of the fuel tank, but also prevent particulate pollutants from being mixed in during the oil filling process.

[0017] The fuel tank can be composed of hollow tubes used to form the drawbar, or welded by two or more hollow tubes.

[0018] The hydraulic oil radiator can be placed above the bucket through the bracket above the bucket. The solenoid valve, hydraulic lock or ball valve can also be placed on the bracket above the bucket.

[0019] In order to make the bulldozing plate move only in a straight line during the forward and backward movement, a guiding frame is provided on the back of the bulldozing plate, the bulldozing oil cylinder is placed inside the guiding frame, guiding rollers are arranged on the left and right sides behind the guiding frame, and a guiding tube cooperating with the guiding rollers is connected to the connecting frame; the side of the bulldozing plate is in contact connection with the bucket through side plate rollers, and the bottom of the bulldozing plate is in contact connection with the bucket through bottom rollers.

[0020] The guiding rollers ensure that the bulldozing plate moves only in a straight line in the front and back directions; the side plate rollers and bottom rollers ensure stable guiding and smooth bulldozing under high loads and prevent the bucket from being jammed.

[0021] The bulldozing oil cylinder is placed inside the guiding frame, and has a good dust-proof effect.

[0022] The guiding rollers, the bottom rollers and the guiding rollers are all of a sealed maintenance-free structure, and the cross-section of the contour of the roller on the guiding roller that plays a guiding role is at a 90° angle, or the cross-section of the contour of the roller on the guiding roller that plays a guiding role is a concave arc curve.

[0023] When the cross-section of the contour of the roller on the guiding roller that plays a guiding role is at a 90° angle, the guiding tube cooperating with the guiding roller is a square tube; when the cross-section of the contour of the roller on the guiding roller that plays a guiding role is a concave arc curve, the guiding tube cooperating with the guiding roller is a seamless round tube.

[0024] The beneficial effects of the present invention:

[0025] (1) The hydraulic components for frequent operation are all external, and the damage repair cost is low. The hydraulic oil used in tractors is relatively expensive, and the external pump only requires very ordinary hydraulic oil, reducing the maintenance cost.

[0026] (2) The bulldozing oil cylinder is placed inside the guiding frame, which has a good dust-proof effect, a long service life, and a clever structural design.

[0027] (3) The guiding rollers ensure that the bulldozing plate moves linearly only in the front-back direction; the side plate rollers and the bottom rollers ensure stable guiding and smooth bulldozing under high loads, preventing the bucket from jamming; the guiding rollers, the side plate rollers, and the bottom plate rollers are all of a sealed maintenance-free structure, reducing the maintenance cost.

[0028] (4) The hydraulic oil radiator can be placed above the bucket through the bracket above the bucket, with a clever design and convenient for maintenance.

[0029] (5) The cross-section of the contour of the roller on the guiding roller that plays a guiding role is at a 90° angle, with low processing cost; when cooperating with the square tube, it has good force guiding performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of the scraper of the present invention Figure One ;

[0031] Figure 2 is a schematic structural diagram of the scraper of the present invention Figure Two ;

[0032] Figure 3 is a schematic structural diagram of the scraper of the present invention Figure Three ;

[0033] Figure 4 is a schematic structural diagram of the scraper of the present invention Figure Four ;

[0034] Figure 5 is a schematic diagram of a hydraulic control system of the scraper of the present invention;

[0035] Figure 6 is a schematic structural diagram of the bulldozing plate assembly of the present invention Figure One ;

[0036] Figure 7 is a schematic structural diagram of the bulldozing plate assembly of the present invention Figure Two ;

[0037] Figure 8 is a schematic structural diagram of the bulldozing plate assembly of the present invention Figure Three ;

[0038] Figure 9 is a schematic structural diagram of the bulldozing plate assembly of the present invention Figure Four ;

[0039] Figure 10 is Figure 8 an enlarged schematic diagram of the connection manner between the middle side plate roller and the side plate;

[0040] Figure 11 is Figure 8 An enlarged schematic view of the connection mode between the bottom roller in the [device name] and the bottom of the bulldozing plate;

[0041] Figure 12 is Figure 8 An enlarged schematic view of the connection mode between the guiding roller in the [device name] and the guiding frame;

[0042] Figure 13 is the structural schematic diagram of the first structure of the guiding roller described in the present invention Figure One ;

[0043] Figure 14 is the structural schematic diagram of the second structure of the guiding roller described in the present invention Figure Two ;

[0044] Figure 15 is Figure 14 A schematic diagram of the sectional view in the A-A direction in the [device name];

[0045] Figure 16 is the sectional view of the side plate roller described in the present invention;

[0046] Figure 17 is the sectional view of the bottom roller described in the present invention;

[0047] Figure 18 is a schematic diagram of a matching mode between the guiding roller of the first structure and the guiding pipe;

[0048] Figure 19 is a partial structural schematic diagram when the guiding roller is of the second structure;

[0049] Figure 20 is another schematic diagram of the hydraulic control system of the scraper described in the present invention.

[0050] In the figure: 1. shaft, 2. shaft sleeve, 3. bearing, 4. bearing limit device, 400. inner end face of the shaft sleeve, 410. flange, 411. washer, 412. snap ring, 5. clamp, 6. bearing seal device, 600. bearing seal end cover, 610. oil seal, 620. dust-proof sealing ring, 630. O-ring, 7. bulldozing plate, 8. side plate, 9. roller assembly, 900. side plate roller, 910. guiding roller, 920. bottom roller, 10. guiding frame, 11. reinforcing rib, 12. guiding roller connecting plate, 13. reinforcing fixing plate, 14. bottom roller fixing plate, 15. mud scraper, 16. protective block, 17. square pipe, 18. contact surface; 19. traction frame, 20. bucket, 21. fuel tank, 22. hydraulic air filter, 23. upper bracket of the bucket, 24. hydraulic oil radiator, 25. connecting frame, 26. solenoid valve, 27. hydraulic lock, 28. depth-limiting cylinder, 29. bulldozing cylinder, 30. depth-limiting wheel, 31. gear pump. Detailed implementation mode

[0051] Embodiment 1

[0052] Combined with Figures 1 to 19 For further illustration of this embodiment, refer to Figures 1 to 5 A scraper with an external oil pump for a hydraulic system, including a bulldozer blade assembly, a bucket 20, a walking swing arm wheel assembly and a hydraulic control system. The bulldozer blade assembly includes a bulldozer blade 7, and the bulldozer blade 7 is placed inside the bucket 20. A traction frame 19 is connected to the front of the bucket 20, and a connecting frame 25 is provided at the back of the bucket 20. The walking swing arm wheel assembly includes a swing arm joint and two depth-limiting wheels 30 connected by the swing arm joint. The walking swing arm wheel group is movably connected to the lower end of the connecting frame 25, and a group of depth-limiting oil cylinders 28 are provided between the upper end of the connecting frame 25 and the walking swing arm wheel group. A bulldozer oil cylinder support for supporting the bulldozer oil cylinder 29 is also provided on the connecting frame 25. One end of the bulldozer oil cylinder 29 is connected to the bulldozer oil cylinder support, and the other end is connected to the back of the bulldozer blade 7. The connection between the bulldozer oil cylinder 29 and the back of the bulldozer blade 7 can be a direct connection or an indirect connection. The hydraulic control system includes an external pump, and the external pump is connected to the tractor PTO output shaft through a coupling. The external pump is used to increase the energy of the hydraulic oil of the depth-limiting oil cylinder.

[0053] The external pump is a gear pump 31, which is connected to the tractor PTO output shaft through a coupling and is placed at the tail of the tractor.

[0054] Refer to Figure Figure 1 、 Figure 2 and Figure 5 . The gear pump is synchronously connected to the group of depth-limiting oil cylinders 28 through a solenoid valve 26 and a hydraulic lock 27. The returned hydraulic oil is cooled by a hydraulic oil radiator 24 and then filtered by a hydraulic air filter 22 to remove impurities and then returned to the fuel tank 21. The hydraulic air filter 22 is vertically installed on the fuel tank cover. The function of the hydraulic air filter: on the one hand, it is used to filter the circulating oil in the hydraulic system and discharge impurities; on the other hand, when the hydraulic system is working, the oil level in the fuel tank sometimes rises and sometimes falls. When it rises, air is discharged from the inside to the outside, and when it falls, air is inhaled from the outside to the inside. In order to purify the oil in the fuel tank, a hydraulic air filter is vertically installed on the fuel tank cover, and the inhaled air can be filtered.

[0055] When the external pump is only used to increase the energy of the hydraulic oil of the depth-limiting oil cylinder, the bulldozer oil cylinder is connected to the solenoid valve on the tractor oil circuit.

[0056] Refer to Figures 1 to 4, above the bucket 20, there is an upper bracket 23, and on the upper bracket 23, there are a hydraulic oil radiator 24, a solenoid valve 26, and a hydraulic lock 27.

[0057] Refer to Figure 1 , the front end of the bucket 20 is connected to the towing frame 19, and the hollow pipe in the towing frame 19 serves as the fuel tank 21. The upper cover plate of the fuel tank 21 is vertically provided with a hydraulic air filter 22; the rear end of the bucket 20 is provided with a connecting frame 25. The connecting frame 25 includes a first cross beam and a second cross beam. The first cross beam and the second cross beam are arranged corresponding to each other up and down and connect the inner sides of the left and right ends of the bucket.

[0058] Refer to Figure 2 , the walking swing arm wheel assembly includes a swing arm joint and a group of depth-limiting wheels 30 connected by the swing arm joint. The walking swing arm wheel assembly is movably connected to the second cross beam. A depth-limiting oil cylinder is arranged between the first cross beam and the walking swing arm wheel assembly. Specifically, the walking swing arm wheel assembly is connected to the second cross beam by a pin shaft. For the two depth-limiting wheels connected by the same swing arm joint, as one depth-limiting wheel rises, the other depth-limiting wheel drops; as one depth-limiting wheel drops, the other depth-limiting wheel rises.

[0059] Refer to Figure 2 , the back of the bulldozing plate 7 is connected with a guiding frame 10, and the bulldozing oil cylinder 29 is placed inside the guiding frame 10. As shown in Figure 1 and Figure 2 , the rear end of the connecting frame 25 is connected with a bulldozing oil cylinder support. One end of the bulldozing oil cylinder 25 is connected to the guiding frame 10, and the other end is connected to the bulldozing oil cylinder support. Guide rollers are arranged on the left and right sides behind the guiding frame, and guiding pipes cooperating with the guide rollers are arranged on the left and right sides of the bulldozing oil cylinder support. With the opening and folding of the bulldozing oil cylinder 29, the bulldozing operation of the bulldozing plate can be realized.

[0060] Refer to Figure 6 and Figure 7 , for further description of the bulldozing plate assembly, a bulldozing plate assembly includes a bulldozing plate 7, side plates 8, and a guiding frame 10 located on the back of the bulldozing plate. The side plates 8 are fixed on both sides of the bulldozing plate 7. The guiding frame 10 is arranged on the back of the bulldozing plate 7. It also includes a roller assembly 9. The roller assembly 9 includes side plate rollers 900 installed on the side plates 8, bottom rollers 920 installed at the bottom of the bulldozing plate, and guide rollers 910 installed on the guiding frame 10; among them, side plate rollers 900 are arranged at both the front and rear ends of the side plates 8.

[0061] Refer to Figure 8 and Figure 12, the guiding rollers 910 are arranged on the left and right sides of the guiding frame 10. At the left and right ends of the rear of the guiding frame, guiding roller connecting plates 12 are respectively provided. The group of guiding roller connecting plates 12 are arranged face to face. The guiding roller connecting plates 12 are provided with notches for the guiding rollers 910 to pass through. The guiding rollers 910 are fixed on the outer sides of the guiding roller connecting plates 12 through clamps 5. When the guiding rollers 910 are subjected to the extrusion of the guiding pipe, the guiding roller connecting plates 12 play a supporting role for the guiding rollers 910. Since the direction of the supporting role is opposite to that of the extrusion, the guiding rollers 910 are not easily shifted inward. In order to further strengthen and fix the guiding frame connecting plates 12, strengthening fixing plates 13 are respectively provided at the upper and lower ends of the group of guiding frame connecting plates 12.

[0062] Refer to Figure 9 , a replaceable protective block 16 is provided at the lower end of the bulldozing plate 7. The protective block 16 is detachably connected to the lower end of the bulldozing plate 7, such as by countersunk screws; the protective block is made of a highly wear-resistant plate.

[0063] Refer to Figure 8 and Figure 9 , the bulldozing plate 7 is arranged in a bent structure, specifically, it can be formed by bending the bulldozing plate section by section; in order to improve the strength of the bulldozing plate, reinforcing ribs 11 are provided section by section on the back of the bulldozing plate 7.

[0064] Such as Figure 9 As shown, after the bulldozing plate is bent, the whole bulldozing plate is nearly arc-shaped, with the upper end pointing forward and upward. This ensures that during the process of leveling the land and transporting soil, the soil will not flip backward; during the process of shoveling soil, the soil continuously squeezes inward towards the bulldozing plate, and the bulldozing plate with a nearly arc-shaped lower end can reduce the resistance of soil entry; compared with the lower end being in a straight plate shape, when the soil continuously enters, because the lower end of the bulldozing plate forms a 90° angle with the bucket, the soil is easily accumulated below, resulting in a large resistance to soil entry and low shoveling efficiency.

[0065] The bulldozing plate undergoes several bends. The bending degree and width of each section can be comprehensively considered. It is necessary to ensure that the soil will not accumulate at the lower end of the bulldozing plate and the soil will not flip backward.

[0066] Refer to Figure 8 and Figure 10 , the side plate rollers 900 are fixedly connected to the side plates through clamps 5. The clamps 5 and the adjusting plates are fixed on both sides of the shaft of the side plate rollers 900. Bolts fasten the clamps, adjusting plates and the side plates. The side plates 8 are provided with holes for the side plate rollers 900 to pass through. The side plate rollers 900 pass through the holes on the side plates 8 and act on the side plates of the scraper.

[0067] Refer toFigure 7 , Figure 8 and Figure 11 , the connection mode between the bottom roller and the bulldozing plate is as follows: there are paired fixing plates for connecting with the bottom roller arranged at the bottom of the bulldozing plate, and holes for the shaft of the bottom roller to pass through are arranged on the fixing plates, and the shaft of the bottom roller is connected with the fixing plates through bolts. In this embodiment, as Figure 11 shown, a mud scraping plate 15 is further arranged on the bottom roller, and the mud scraping plate can swing up and down. If the mud on the bottom roller is too sticky, counterweights can be added at the hole positions of the mud scraping plate; the mud scraping plate can also be set to be fixed.

[0068] The side plate roller 900, the bottom roller 920 and the guiding roller 910 are all sealed and maintenance-free rollers.

[0069] Combine Figures 13 to 17 The structure of the sealed and maintenance-free roller is described. Taking the guiding roller as an example, as Figures 13 to 15 shown, a sealed and maintenance-free triangular guiding roller includes a shaft 1, a shaft sleeve 2, and a group of bearings 3 sleeved on the shaft 1. Bearing limiting devices 4 for preventing the bearings from making axial movement are arranged at both ends of the bearings 3. Shaft fastening devices for fixing the roller are arranged at both ends of the shaft 1. A bearing sealing device 6 is arranged at the outer end face of the bearing. The longitudinal section of the contour for guiding on the shaft sleeve 2 forms a 90° angle, and a fillet is provided at the angle.

[0070] Refer to Figure 15 , the bearing sealing device 6 includes: an oil seal 610 and a bearing sealing end cover 600. The bearing sealing end cover 600 is connected with the shaft sleeve 2 through countersunk head screws; a dust-proof sealing ring 620 is further arranged between the bearing sealing end cover 600 and the shaft 1; an O-ring seal 630 is arranged between the bearing sealing end cover 600 and the shaft sleeve 2; the bearings of the guiding roller are sealed multiple times by an oil seal, sealing rings (including a dust-proof sealing ring and an O-ring seal) and a bearing sealing end cover, and are maintenance-free for life.

[0071] Refer to Figure 15 , the bearing limiting device 4 includes: an inner end face 400 of the shaft sleeve for axially limiting the bearing 3 from the inner side of the group of bearings, and an outer bearing limiting member for axially limiting the bearing from the outside; in this embodiment, the outer bearing limiting member is specifically: the outer bearing limiting member of one of the bearings includes a circlip 412 and a washer 411. The washer 411 is arranged between the circlip 412 and the bearing 3, and the circlip 412 axially limits the bearing 3 by pressing the washer 411 to prevent the axial movement of the bearing 3; the outer bearing limiting member of the other bearing includes a flange 410 arranged on the shaft 1.

[0072] The bearing limit device 4 may also consider the following implementation manners: The bearing outer limit members of the two bearings both include snap rings, and the snap rings tightly press the bearings to prevent the bearings from moving axially; or the bearing outer limit members of the two bearings both include snap rings and washers, the washers are arranged between the snap rings and the bearings, and the snap rings axially limit the bearings by tightly pressing the washers.

[0073] Refer to Figure 15 , the two ends of the shaft 1 fix the guide rollers through the clamps 5, and other fixing methods can also be considered.

[0074] The bearing 3 is selected as a double-row deep groove ball bearing or a double-row angular contact ball bearing.

[0075] Refer to Figure 16 and Figure 17 , the side plate rollers and the bottom rollers can adopt the same bearing sealing device, bearing limit device and shaft fastening device as the guide rollers as described in Figure 15 .

[0076] Figure 18 Only for understanding the cooperation mode of the triangular guide roller 910 and the square pipe 17, the guide roller 910 and the square pipe 17 are cooperated through the contact surface 18.

[0077] Embodiment 2

[0078] Different from Embodiment 1, the guide roller is a kidney-shaped roller. Refer to Figure 19 , the kidney-shaped guide roller is arranged behind the guide frame, the longitudinal section of the shaft sleeve of the kidney-shaped guide roller that plays a guiding role is arc-shaped, and the kidney-shaped guide roller is cooperated with the seamless circular pipe.

[0079] Embodiment 3

[0080] Different from Embodiment 1, the solenoid valve connected to the gear pump is a two-way valve. The gear pump is connected to the solenoid valve including two oil paths. One oil path of the solenoid valve is synchronously connected to the group of depth-limiting cylinders, and the other oil path of the solenoid valve is connected to the bulldozing cylinder. Further, an external ball valve is arranged on the oil path where the solenoid valve is connected to the rodless cavity of the group of depth-limiting cylinders.

Claims

1. A scraper with an external oil pump for a hydraulic system, comprising a bulldozing plate assembly, a bucket, two groups of walking swing arm wheel assemblies, and a hydraulic control system. The bulldozing plate assembly includes a bulldozing plate, which is placed inside the bucket. A traction frame is connected to the front of the bucket, and a connecting frame is provided at the back of the bucket. Each group of walking swing arm wheel assemblies includes a swing arm joint and two depth-limiting wheels connected by the swing arm joint. The walking swing arm wheel group is movably connected to the lower end of the connecting frame, and a group of depth-limiting oil cylinders are provided between the upper end of the connecting frame and the walking swing arm wheel group. A bulldozing oil cylinder support for supporting the bulldozing oil cylinder is also provided on the connecting frame. One end of the bulldozing oil cylinder is connected to the bulldozing oil cylinder support, and the other end is connected to the back of the bulldozing plate. It is characterized in that: The hydraulic control system includes an external pump, which is connected to the PTO output shaft of the tractor through a coupling; the external pump is used to increase the energy of the hydraulic oil in the depth-limiting cylinder, or the external pump is used to increase the energy of the hydraulic oil in the depth-limiting cylinder and the bulldozing cylinder, and the external pump uses independent ordinary hydraulic oil; a guiding frame is provided on the back of the bulldozing plate, the bulldozing cylinder is placed in the guiding frame, guiding rollers are arranged on the left and right sides behind the guiding frame, and a guiding tube that cooperates with the guiding rollers is connected to the connecting frame; the side of the bulldozing plate is in contact connection with the bucket through side plate rollers, and the bottom of the bulldozing plate is in contact connection with the bucket through bottom rollers; the cross-section of the contour that plays a guiding role on the guiding roller forms a 90° angle.

2. The scraper with an externally mounted oil pump for the hydraulic system according to claim 1, characterized in that: The external pump is used to increase the energy of the hydraulic oil in the depth-limiting cylinder, and the external pump is synchronously connected to the group of depth-limiting cylinders through an external solenoid valve; the bulldozing cylinder is connected to the solenoid valve on the tractor oil circuit.

3. The scraper with an externally mounted oil pump for a hydraulic system according to claim 2, characterized in that: An external hydraulic lock is provided between the solenoid valve and the group of depth-limiting cylinders.

4. The scraper with an externally-mounted oil pump for the hydraulic system according to claim 1, characterized in that: The external pump is used to increase the energy of the hydraulic oil in the depth-limiting cylinder and the bulldozing cylinder, the external pump is connected to an external solenoid valve with 2 oil circuits, one oil circuit of the solenoid valve is synchronously connected to the group of depth-limiting cylinders, and the other oil circuit of the solenoid valve is connected to the bulldozing cylinder.

5. The scraper with an externally mounted oil pump for a hydraulic system according to claim 4, characterized in that: An external ball valve is provided on the oil circuit where the solenoid valve is connected to the rodless cavity of the group of depth-limiting cylinders.

6. The scraper with an externally mounted oil pump for the hydraulic system according to any one of claims 2 to 5, characterized in that: An external hydraulic oil radiator and an external hydraulic air filter are also provided. One end of the hydraulic oil radiator is connected to the oil return port of the solenoid valve, the other end is connected to the hydraulic air filter, and the hydraulic air filter is connected to the fuel tank.

7. The scraper with an externally mounted oil pump for a hydraulic system according to claim 6, characterized in that: The fuel tank is a hollow tube used to form the towing frame.

8. The scraper with an externally mounted oil pump for the hydraulic system according to claim 1, characterized in that: The guiding rollers, the bottom rollers, and the guiding rollers are all of a sealed and maintenance-free structure.

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