LIFTING DEVICE AND LOADER USING SAME

Description

The present application claims priority to Chinese Patent Application No. 202422743206.5, filed with the China National Intellectual Property Administration on Nov. 11, 2024 and entitled “Lifting Device and Loader Using Same”, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates to the technical field of loading machinery, and in particular to a lifting device and a loader using the same.

BACKGROUND

Currently, some loading machines use vertical lifting devices to achieve lifting of a working end, so as to meet diverse working condition requirements and achieve better unloading height and unloading distance.

In related technical solutions, the vertical lifting device usually uses a lifting cylinder and a linkage structure to achieve lifting of the working end. However, the layout of the lifting cylinder and the linkage structure is often unreasonable, resulting in a large motion trajectory or fluctuation range of the working end, or presence of inflection points, poor smoothness, and proneness to material spillage.

SUMMARY OF THE INVENTION

In view of this, the present application provides a lifting device and a loader using the same, to solve the problem of poor smoothness of movement of an existing vertical lifting device.

In a first aspect, the present application provides a lifting device including: a frame; an arm body disposed above the frame, the arm body having a first end portion and a second end portion that are opposite each other, the first end portion having a lowest position and a highest position; a first connecting rod, wherein one end of the first connecting rod is hinged to the frame, forming a first hinge point; and the other end of the first connecting rod is hinged to the second end portion, forming a second hinge point; a second connecting rod located on a side of the first connecting rod close to the first end portion, wherein one end of the second connecting rod is hinged to the frame, forming a third hinge point; and the other end of the second connecting rod is hinged to the second end portion, forming a fourth hinge point; and a first driving member, wherein one end of the first driving member is hinged to the frame, forming a fifth hinge point; the other end of the first driving member is hinged to the second end portion, forming a sixth hinge point; and the first driving member is configured to move the first end portion between the lowest position and the highest position when the first driving member extends or retracts, wherein, in a first direction, the first hinge point is located above the third hinge point and above the fifth hinge point; and in a second direction, the fifth hinge point is located between the first hinge point and the third hinge point; in a direction from the first end portion to the second end portion, the fourth hinge point is located between the second hinge point and the sixth hinge point; and a distance between the second hinge point and the fourth hinge point is greater than a length of the first connecting rod and less than a length of the second connecting rod, wherein the first direction is a height direction, and the second direction is a horizontal direction.

Optionally, when the first end portion is at the lowest position, the second hinge point is located on a side of the first hinge point close to the first end portion; and/or when the first end portion is at the lowest position, an angle is formed at a connection between the first driving member and the arm body, and the angle ranges from 80° to 100°; and/or the lifting device is applied to a loader including a cab and a traveling drive device, the traveling drive device having a traveling device drive shaft; and in the second direction, the third hinge point is located between the cab and the traveling device drive shaft.

Optionally, the frame has a head and a tail; the first connecting rod, the second connecting rod and the first driving member are all hinged to the tail; and the second end portion and the first connecting rod are both located on a side of the tail close to the head, and the first end portion is located on a side of the head away from the tail.

Optionally, the arm body includes an intermediate portion, wherein one end of the intermediate portion is plug-connected to the first end portion, and a first hinge hole is formed at a location where the intermediate portion is plug-connected to the first end portion, the first hinge hole being used for connecting a loading device; and the other end of the intermediate portion is plug-connected to the second end portion, and a second hinge hole is formed at a location where the intermediate portion is plug-connected to the second end portion, the first driving member being hinged to the second end portion through the second hinge hole.

Optionally, two sets of arm bodies are provided, the two sets of arm bodies being spaced apart along a third direction, and respective sides of the two sets of arm bodies that face each other being inner sides thereof; and the first end portion includes a first straight segment, a bent segment and a second straight segment connected in sequence, wherein the first straight segment is plug-connected to the intermediate portion, the bent segment is bent towards the inner side, and the second straight segment is used for connecting the loading device; and along the third direction, the first straight segment has a larger dimension than the second straight segment, wherein the third direction is perpendicular to both the first direction and the second direction.

Optionally, the first end portion includes a first side plate, a second side plate, a top plate, and a bottom plate, wherein the first side plate and the second side plate are arranged to be spaced apart along the third direction, the top plate is connected to and covers the top of the first side plate and the top of the second side plate, and the bottom plate is connected to and covers the bottom of the first side plate and the bottom of the second side plate; and the first side plate, the second side plate, the top plate and the bottom plate together form the first straight segment, the bent segment and the second straight segment, wherein in the bent segment, one side of the top plate along the third direction protrudes beyond the first side plate, and/or the other side of the top plate along the third direction protrudes beyond the second side plate; and/or in the bent segment, one side of the bottom plate along the third direction protrudes beyond the first side plate, and/or the other side of the bottom plate along the third direction protrudes beyond the second side plate.

Optionally, in an extension direction of the first straight segment, an end face of the first side plate away from the second straight segment, an end face of the second side plate away from the second straight segment, an end face of the top plate away from the second straight segment, and an end face of the bottom plate away from the second straight segment are arranged in a staggered manner.

Optionally, the arm body further includes a first hinge seat; the first straight segment has an inner surface on an inner side thereof, and the bent segment has a bent surface on an inner side thereof; and the first hinge seat is fitted against and connected to at least a portion of the inner surface and is fitted against and connected to at least a portion of the bent surface.

Optionally, the lifting device further includes a first crossbeam and a second crossbeam, the first crossbeam being fixedly connected between two first end portions of the two sets of arm bodies, and the second crossbeam being fixedly connected between two second end portions of the two sets of arm bodies.

In a second aspect, the present application further provides a loader including a lifting device and a loading device, wherein the lifting device is the lifting device in the above-mentioned first aspect or any implementation of the first aspect; and the loading device is connected to the first end portion of the arm body of the lifting device.

In this solution, the frame and the arm body form a four-bar linkage by means of the first connecting rod and the second connecting rod, and the first driving member is used to provide a driving force for the arm body. In a height direction, a first hinge point between the first connecting rod and the frame is located above a third hinge point between the second connecting rod and the frame, and above a fifth hinge point between the first driving member and the frame; in a horizontal direction, the fifth hinge point is located between the first hinge point and the third hinge point; and along a direction from the first end portion to the second end portion, a fourth hinge point between the second connecting rod and the second end portion is located between a second hinge point between the first connecting rod and the second end portion and a sixth hinge point between the first driving member and the second end portion; and a distance between the second hinge point and the fourth hinge point is greater than a length of the first connecting rod and less than a length of the second connecting rod. The technical solution of the present application can shorten the lengths of the first connecting rod and the second connecting rod by reasonably arranging the points of the four-bar linkage, so that the lifting device has a compact structure and smooth appearance. Moreover, in a lifting process, the first end portion of the arm body can first extend forward for a distance and then perform an ascending movement in an approximately vertical way. During the entire process, its motion trajectory has no large fluctuations and abrupt change points, thereby improving the lifting smoothness and avoiding problems such as material spillage.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly describe the technical solutions in specific implementations of the present application or in the prior art, the drawings for use in the description of the specific implementations or the prior art will be briefly described below. Apparently, the drawings in the following description merely represent some implementations of the present application, and persons of ordinary skill in the art may still derive other drawings from these drawings without creative efforts.

FIGS. 1 to 5 are schematic diagrams of movement states of a lifting device according to an embodiment of the present application during a lifting process.

FIG. 1 is a schematic structural diagram when a first end portion of an arm body is at a lowest position;

FIG. 2 is a schematic structural diagram of a state during clockwise rotation of a first connecting rod;

FIG. 3 is a schematic structural diagram at transition from clockwise rotation to counterclockwise rotation of the first connecting rod;

FIG. 4 is a schematic structural diagram of a state during counterclockwise rotation of the first connecting rod;

FIG. 5 is a schematic structural diagram when the first end portion of the arm body is at a highest position;

FIG. 6 is a schematic structural diagram of an arm body according to an embodiment of the present application;

FIG. 7 is a top view of an alternative arm body according to an embodiment of the present application;

FIG. 8 is a perspective view of the alternative arm body according to an embodiment of the present application; and

FIG. 9 is a schematic structural diagram of a first connecting rod according to an embodiment of the present application.

REFERENCE NUMERALS

• • 1: arm body; 2: first connecting rod; 3: second connecting rod; 4: first driving member; 5: frame; 5a: head; 5b: tail; 6: first crossbeam; 7: second crossbeam; 8: cab; 9: second hinge seat; 10: traveling device drive shaft; 11: first end portion; 11a: first straight segment; 11b: bent segment; 11c: second straight segment; 12: intermediate portion; 13: second end portion; 14: first hinge hole; 15: second hinge hole; 16: outer bent plate; 17: inner bent plate; 18: first outer straight plate; 19: first inner straight plate; 20: second outer straight plate; 21: second inner straight plate; 22: first hinge seat; 23: inner surface; 24: bent surface; 25: first reinforcing plate; 26: second reinforcing plate; 27: first side plate; 28: second side plate; 29: top plate; 30: bottom plate; 31: third side plate; 32: fourth side plate; 33: fifth side plate; 34: sixth side plate; 35: connecting plate; 36: third reinforcing plate; 37: second driving member; 38: bucket;
  • A: first hinge point; B: second hinge point; C: third hinge point; D: fourth hinge point; E: fifth hinge point; F: sixth hinge point;
  • Z: first direction; X: second direction; Y, third direction.

DETAILED DESCRIPTION

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below clearly and completely with reference to the accompanying drawings in the embodiments of the present application. Apparently, the embodiments described are merely some rather than all of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

The embodiments of the present application are described below with reference to FIGS. 1 to 9.

According to an embodiment of the present application, there is provided a loader. The loader includes a lifting device and a loading device. The lifting device includes an arm body 1 and a frame 5. The arm body 1 has a first end portion (11) and a second end portion (13) that are opposite each other. The first end portion 11 is connected to the loading device, and the second end portion 13 is hinged to the frame 5.

It may be understood that the present application does not specifically limit the type of the loader, as long as it can utilize the lifting device of the present application to achieve lifting and lowering operations of the loading device. The loader of the present application includes, but is not limited to, wheel loaders, crawler loaders, and other skid steer loaders.

Further, as shown in FIG. 1, the lifting device includes the above-mentioned frame 5, the above-mentioned arm body 1, a first connecting rod 2, a second connecting rod 3, and a first driving member 4. The arm body 1 is disposed above the frame 5. The arm body 1 has a first end portion 11 and a second end portion 13 that are opposite each other. The first end portion 11 of the arm body 1 is connected to the loading device. The first end portion 11 has a lowest position and a highest position. When moving between the lowest position and the highest position, the first end portion 11 drives the loading device to ascend or descend, thereby achieving a lifting or lowering operation of materials. The second end portion 13 of the arm body 1 is hinged to the frame 5 via the first connecting rod 2 and the second connecting rod 3, and the first driving member 4 is provided between the second end portion 13 of the arm body 1 and the frame 5. The first driving member 4 is configured to drive the second end portion 13 to rotate when the first driving member extends or retracts, thereby moving the first end portion 11 between the lowest position and the highest position.

Exemplarily, the first driving member 4 may be a hydraulic cylinder, a pneumatic cylinder, an electric telescopic rod, etc., preferably a hydraulic oil cylinder, which has a simple structure and high reliability.

Specifically, one end of the first connecting rod 2 is hinged to the frame 5, forming a first hinge point A; and the other end of the first connecting rod 2 is hinged to the second end portion 13, forming a second hinge point B. The second connecting rod 3 is located on a side of the first connecting rod 2 close to the first end portion 11, wherein one end of the second connecting rod 3 is hinged to the frame 5, forming a third hinge point C; and the other end of the second connecting rod 3 is hinged to the second end portion 13, forming a fourth hinge point D. One end of the first driving member 4 is hinged to the frame 5, forming a fifth hinge point E. Specifically, a fixed end of the first driving member 4 is hinged to the frame 5. The other end of the first driving member 4 is hinged to the second end portion 13, forming a sixth hinge point F. Specifically, a drive end of the first driving member 4 is hinged to the second end portion 13. In a first direction Z, the first hinge point A is located above the third hinge point C and above the fifth hinge point E. In a second direction X, the fifth hinge point E is located between the first hinge point A and the third hinge point C. In a direction from the first end portion 11 to the second end portion 13, i.e., in an extension direction of the arm body 1, the fourth hinge point D is located between the second hinge point B and the sixth hinge point F. Moreover, a distance between the second hinge point B and the fourth hinge point D is greater than a length of the first connecting rod 2 and less than a length of the second connecting rod 3.

The first direction Z is a height direction, and the second direction X is a horizontal direction.

It may be understood that in this embodiment, the length of the second connecting rod 3 is set to be greater than that of the first connecting rod 2.

It may be understood that in this embodiment, since the arm body 1 is disposed above the frame 5, for each of the first connecting rod 2, the second connecting rod 3 and the first driving member 4, the hinge point with the arm body 1 is located above the corresponding hinge point with the frame 5, i.e. the second hinge point B is located above the first hinge point A, the fourth hinge point D is located above the third hinge point C, and the sixth hinge point F is located above the fifth hinge point E.

In this embodiment, the frame 5 and the arm body 1 form a four-bar linkage by means of the first connecting rod 2 and the second connecting rod 3, and the first driving member 4 is used to provide a driving force for the arm body 1. The technical solution of the present application can shorten the lengths of the first connecting rod 2 and the second connecting rod 3 by reasonably arranging the points of the four-bar linkage, so that the lifting device has a compact structure and smooth appearance. Moreover, in a lifting process, the first end portion 11 of the arm body 1 can first extend forward for a distance and then perform an ascending movement in an approximately vertical way. During the entire process, its motion trajectory has no large fluctuations and abrupt change points, thereby improving the lifting smoothness and avoiding problems such as material spillage.

It may be understood that the first connecting rod 2, the second connecting rod 3, and the first driving member 4 may be rotationally connected to the frame 5 and the arm body 1 via hinge shafts, and the above-mentioned hinge points are located on axes of the hinge shafts corresponding to the hinge parts.

In some embodiments, in order to ensure a telescopic stroke of the first driving member 4 to provide a sufficient digging force for the arm body 1, the fifth hinge point E between the first driving member 4 and the frame 5 is located at the bottom of the frame 5, i.e., in the first direction Z, the fifth hinge point E is located below the first hinge point A and the third hinge point C.

In some embodiments, when the first end portion 11 is at the lowest position, an angle is formed at a connection between the first driving member 4 and the arm body 1. More specifically, an angle is formed at a connection between the first driving member 4 and the second end portion 13. Moreover, the angle ranges from 80° to 100°, so that the first driving member 4 is disposed approximately perpendicular to the arm body 1, so as to provide a large digging force for the arm body 1. Preferably, the angle ranges from 85° to 95°. More preferably, the angle is 90°, that is, the first driving member 4 and the arm body 1 are disposed perpendicular to each other.

More specifically, in some embodiments, a second hinge seat 9 is fixedly connected to the frame 5, and one end of the second connecting rod 3 is hinged to the second hinge seat 9, i.e. the third hinge point C between the second connecting rod 3 and the frame 5 is formed on the second hinge seat 9. The second end portion 13 of the arm body 1 is provided with a protrusion which extends downward, and the other end of the second connecting rod 3 is hinged to the protrusion, that is, the fourth hinge point D between the second connecting rod 3 and the second end portion 13 is formed on the protrusion. As shown in FIGS. 1 to 5, in the first direction Z, i.e. in the height direction, the fourth hinge point D is always located below the second hinge point B and the sixth hinge point F.

The first hinge point A between the first connecting rod 2 and the frame 5, and the second hinge point B between the first connecting rod and the second end portion 13 are both located on a side of the third hinge point C and the fourth hinge point D away from the first end portion 11, i.e., at a rear end of the entire loader.

Further, in some embodiments, as shown in FIG. 1, when the first end portion 11 is at the lowest position, the second hinge point B is located above the first hinge point A and offset toward the first end portion 11, that is, the second hinge point B is located on a side of the first hinge point A close to the first end portion 11, so as to provide a larger rotation space for the first connecting rod 2, which is conducive to the compactness of a rear end structure of the four-bar linkage and the stability of the entire loader.

In some embodiments, the frame 5 has a head 5a and a tail 5b, and the first connecting rod 2, the second connecting rod 3, and the first driving member 4 are all hinged to the tail 5b. In a direction from the head 5a to the tail 5b of the frame 5, the second connecting rod 3, the first driving member 4, and the first connecting rod 2 are arranged sequentially, that is, the first connecting rod 2 is located on a rear side of the tail 5b of the frame 5. Moreover, the second end portion 13 and the first connecting rod 2 are both located on a side of the tail 5b close to the head 5a, and the first end portion 11 is located on a side of the head 5a away from the tail 5b. Throughout the lifting process of the lifting device, the first end portion 11 and the first connecting rod 2 can remain on a front side of an end face of the tail 5b of the frame 5, i.e., on a front side of the rear end of the entire loader, to improve the operational performance in narrow spaces.

Specifically, the position where the first connecting rod 2 is hinged to the second end portion 13 is located at a tail end of the second end portion 13, so that during the lifting process, a tail end of the arm body 1 is substantially flush with the end face of the tail 5b of the frame 5, or is located on the front side of the end face of the tail 5b of the frame 5.

In some embodiments, the loader further includes a cab 8 and a traveling drive device. The cab 8 is fixedly connected above the head 5a of the frame 5. The arm body 1 is located on at least one side of the cab 8. The traveling drive device is fixedly connected below the frame 5, and configured to drive the loader to travel. The traveling drive device has a traveling device drive shaft 10.

The third hinge point C between the second connecting rod 3 and the frame 5 is located on a side of the cab 8 close to the tail 5b of the frame 5, i.e., on a rear side of the cab 8; and is located on a side close to the head 5a of the frame 5 above the traveling device drive shaft 10. That is, in the second direction X, the third hinge point C is located between the cab 8 and the traveling device drive shaft 10. More specifically, the third hinge point C is located on the rear side of the cab 8 and on a front side of the traveling device drive shaft 10. This configuration can improve the stability of the loader, ensure a large tipping load of the loader, and avoid tipping.

Along a width direction of the cab 8, i.e., the third direction Y in FIGS. 1 to 5, the second connecting rod 3 is located on one side or symmetrically on both sides of the cab 8 in the third direction Y, and between the cab 8 and the first driving member 4. The second connecting rod 3 and the first driving member 4 are spaced apart in the third direction Y to avoid interfering with each other. It may be understood that the third direction Y is perpendicular to both the above-mentioned first direction Z and second direction X.

The lifting process of the lifting device of the present application is illustrated in FIGS. 1 to 5.

When the loading device is at a lowest position, the first end portion 11 of the arm body 1 is at the lowest position, as shown in FIG. 1. When lifting begins, the first driving member 4 extends, during which the first connecting rod 2 moves in a clockwise direction, and the second connecting rod 3 moves in a counterclockwise direction, as shown in FIG. 2. As the first driving member 4 continues to extend and causes lifting, reaching a position shown in FIG. 3, the second hinge point B, the fourth hinge point D, and the third hinge point C are approximately aligned on a straight line. At this time, the first connecting rod 2 reaches its maximum clockwise rotation angle. As the first driving member 4 continues to extend and causes lifting, the first connecting rod 2 starts rotating counterclockwise under the drive of the second connecting rod 3, and the second connecting rod 3 continues to rotate counterclockwise, as shown in FIG. 4. As the lifting continues, reaching a position shown in FIG. 5, the first connecting rod 2 reaches its maximum counterclockwise rotation angle, and the second connecting rod 3 also reaches its maximum counterclockwise rotation angle. At this time, the loading device is at a highest position, that is, the first end portion 11 of the arm body 1 is at the highest position.

During the entire lifting process, the first connecting rod 2 moves clockwise and then counterclockwise, while the second connecting rod 3 moves counterclockwise throughout. The clockwise rotation angle of the first connecting rod 2 is smaller than its counterclockwise rotation angle, and the counterclockwise rotation angle of the second connecting rod 3 is less than 65°. This can ensure that tail ends of the first connecting rod 2 and the arm body 1 do not exceed the end face of the tail 5b of the frame 5, i.e., do not exceed an end face of the rear end of the entire loader, so as to improve the operational performance in narrow spaces.

For the lifting device of the present application, by reasonably setting the positions of the hinge points between the first connecting rod 2, the second connecting rod 3 and the first driving member 4, and the frame 5 and the arm body 1, the structure of a rear end of the lifting device is more compact, and the stability of the structure and the smoothness of the appearance are improved. Moreover, in the entire lifting process, the first end portion 11 of the arm body 1 first extends forward for a distance and then performs an ascending movement in an approximately vertical way. During the entire process, its motion trajectory is smooth, and has no large fluctuations and abrupt change points, thereby avoiding material spillage.

Further, in some embodiments, as shown in FIG. 6, the arm body 1 is of a three-segment configuration, specifically including the above-described first end portion 11 and second end portion 13, and an intermediate portion 12 connected between the first end portion 11 and the second end portion 13. One end of the intermediate portion 12 is plug-connected to the first end portion 11, and a first hinge hole 14 is formed at a location where the intermediate portion 12 is plug-connected to the first end portion 11. The first hinge hole 14 is used for connecting the above-mentioned loading device. The other end of the intermediate portion 12 is plug-connected to the second end portion 13, and a second hinge hole 15 is formed at a location where the intermediate portion 12 is plug-connected to the second end portion 13. The first driving member 4 is hinged to the second end portion 13 through the second hinge hole 15. With this configuration, the first end portion 11, the second end portion 13, and the intermediate portion 12 are formed as an integral structure, and the first end portion 11, the second end portion 13, and the intermediate portion 12 jointly bear bending moments at the first hinge hole 14 and the second hinge hole 15, thereby providing the load-bearing capacity of the arm body 1.

It may be understood that the first hinge hole 14 is formed at the position where the first end portion 11 is plug-connected to the intermediate portion 12, that is, the first end portion 11 and the intermediate portion 12 together form the first hinge hole 14, which ensures the structural strength at the first hinge hole 14. The second hinge hole 15 is formed at the position where the second end portion 13 is plug-connected to the intermediate portion 12, that is, the second end portion 13 and the intermediate portion 12 together form the second hinge hole 15, which ensures the structural strength at the second hinge hole 15.

As shown in FIG. 1, the above-mentioned loading device specifically includes a second driving member 37 and a bucket 38, wherein a driving end of the second driving member 37 is hinged to the bucket 38, and a fixed end of the second driving member 37 is hinged in the first hinge hole 14.

In some embodiments, a first hinge seat 22 is further fixedly connected to the first end portion 11 of the arm body 1. The first hinge seat 22, the first end portion 11, and the intermediate portion 12 together form the first hinge hole 14. The fixed end of the second driving member 37 is hinged to the arm body 1 via the first hinge seat 22 and the first hinge hole 14.

Exemplarily, the second driving member 37 may be a hydraulic cylinder, a pneumatic cylinder, an electric telescopic rod, etc., preferably a hydraulic oil cylinder, which has a simple structure and high reliability.

Exemplarily, the intermediate portion 12 may be configured as a rectangular beam structure, that is, a longitudinal cross-section of the intermediate portion 12 is rectangular. One end of the rectangular beam structure is inserted into the first end portion 11 and welded to the first end portion 11, and the other end of the rectangular beam structure is inserted into the second end portion 13 and welded to the second end portion 13. It may be understood that the intermediate portion 12 may also be configured as other structures, as long as it can be adapted to the shapes and configurations of the first end portion 11 and the second end portion 13.

Further, in some embodiments, as shown in FIGS. 7 and 8, two sets of arm bodies 1 are provided. The two sets of arm bodies 1 are spaced apart along the third direction Y. More specifically, the two sets of arm bodies 1 are arranged in parallel on two sides of the cab 8 along the third direction Y, and extend between a front side and the rear side of the cab 8. For the two first end portions 11 of the two sets of arm bodies 1, along the third direction Y, a distance between ends of the two first end portions 11 close to the loading device is smaller than a distance between ends of the two first end portions close to the intermediate portion 12, that is, a front end of the arm body 1 adopts an inwardly retracting structure, to reduce a forward extension distance of the front end of the arm body 1 and improve the stability and working capacity of the lifting device.

Specifically, in some embodiments, the first end portion 11 includes a first straight segment 11a, a bent segment 11b and a second straight segment 11c connected in sequence. The first straight segment 11a is plug-connected to the intermediate portion 12. The bent segment 11b is bent towards the inner side of the arm body 1. The second straight segment 11c is used for connecting the loading device so that the second straight segment 11c is located on an inner side of the first straight segment 11a. It is to be noted that the inner sides of the arm bodies 1 refer to respective sides of the two sets of arm bodies 1 that face each other, i.e. their respective sides close to the cab 8. Exemplarily, the first end portion 11 may be substantially “S”-shaped.

In some embodiments, along the third direction Y, the first straight segment 11a has a larger dimension than the second straight segment 11c, so as to facilitate transition to the bent segment 11b and ensure an inwardly retracting effect.

More specifically, in some embodiments, the first end portion 11 includes a first side plate 27, a second side plate 28, a top plate 29, and a bottom plate 30. The first side plate 27 and the second side plate 28 are arranged to be spaced apart along the third direction Y. The top plate 29 is connected to and covers the top of the first side plate 27 and the top of the second side plate 28. The bottom plate 30 is connected to and covers the bottom of the first side plate 27 and the bottom of the second side plate 28. The first side plate 27, the second side plate 28, the top plate 29 and the bottom plate 30 together form the first straight segment 11a, the bent segment 11b and the second straight segment 11c. The first side plate 27, the second side plate 28, the top plate 29 and the bottom plate 30 enable the inner cavity of the arm body 1 to be completely closed, making it less susceptible to rainwater intrusion and achieving better corrosion resistance. Exemplarily, the first side plate 27, the second side plate 28, the top plate 29 and the bottom plate 30 may be connected into an integral structure by welding, plug-connection, snap-fitting, bolted connection, etc., preferably by welding.

In some embodiments, in the bent segment 11b, one side of the top plate 29 along the third direction Y protrudes beyond the first side plate 27, or the other side of the top plate 29 along the third direction Y protrudes beyond the second side plate 28, or the two sides of the top plate 29 along the third direction Y respectively protrude beyond the first side plate 27 and the second side plate 28, to reduce stress concentration in the bent segment 11b and improve the structural strength.

In some embodiments, in the bent segment 11b, one side of the bottom plate 30 along the third direction Y protrudes beyond the first side plate 27, or the other side of the bottom plate 30 along the third direction Y protrudes beyond the second side plate 28, or the two sides of the bottom plate 30 along the third direction Y respectively protrude beyond the first side plate 27 and the second side plate 28, to further reduce stress concentration in the bent segment 11b and improve the structural strength.

In some embodiments, in the bent segment 11b, the two sides of the top plate 29 along the third direction Y respectively protrude beyond the first side plate 27 and the second side plate 28, and the two sides of the bottom plate 30 along the third direction Y respectively protrude beyond the first side plate 27 and the second side plate 28. That is, in the bent segment 11b, the area covered by the top plate 29 and the bottom plate 30 is greater than the cross-sectional area of a cavity formed between the first side plate 27 and the second side plate 28.

Specifically, as shown in FIGS. 7 and 8, the first side plate 27 is located on an outer side of the arm body 1, and the second side plate 28 is located on an inner side of the arm body 1. In a direction away from the intermediate portion 12, the first side plate 27 includes a first outer straight plate 18, an outer bent plate 16, and a second outer straight plate 20 connected in sequence. The first outer straight plate 18, the outer bent plate 16, and the second outer straight plate 20 may be integrally formed, and substantially “S” shaped. The second side plate 28 includes a first inner straight plate 19, an inner bent plate 17, and a second inner straight plate 21 connected in sequence. The first inner straight plate 19, the inner bent plate 17, and the second inner straight plate 21 may be integrally formed, and substantially “S”-shaped.

The first outer straight plate 18 and the first inner straight plate 19 are arranged opposite each other and form the above-described first straight segment 11a. The outer bent plate 16 and the inner bent plate 17 are arranged opposite each other and are both bent toward the inner side of the arm body 1 to form the above-described bent segment 11b. The second outer straight plate 20 and the second inner straight plate 21 are arranged opposite each other and form the above-described second straight segment 11c.

In some embodiments, the intermediate portion 12 is configured as a rectangular beam structure, and the second end portion 13 includes a third side plate 31 and a fourth side plate 32 spaced apart along the third direction Y. Along the third direction Y, a distance between the first outer straight plate 18 and the first inner straight plate 19 is equal to a distance between the third side plate 31 and the fourth side plate 32. Specifically, the distance between the first outer straight plate 18 and the first inner straight plate 19, and the distance between the third side plate 31 and the fourth side plate 32 are both equal to a dimension of the rectangular beam in the third direction Y, so as to facilitate plug-connection with the rectangular beam.

In some embodiments, as shown in FIG. 7, along the third direction Y, a distance between the second outer straight plate 20 and the second inner straight plate 21 is less than a distance between the first outer straight plate 18 and the first inner straight plate 19, so that the first straight segment 11a has a larger dimension than the second straight segment 11c in the third direction Y. This configuration facilitates smooth transition of the first outer straight plate 18 and the second outer straight plate 20 to two ends of the outer bent plate 16, and smooth transition of the first inner straight plate 19 and the second inner straight plate 21 to two ends of the inner bent plate 17, achieving a better inward retracting effect of the arm body 1 and higher stability of the entire loader.

In some embodiments, a first reinforcing plate 25 is provided between the outer bent plate 16 and the inner bent plate 17 to improve the structural strength of the bent segment 11b. Preferably, the first reinforcing plate 25 is plug-welded to a stress concentration position between the outer bent plate 16 and the inner bent plate 17, making the structural strength more reliable.

Further, in some embodiments, in an extension direction of the first straight segment 11a, an end face of the first side plate 27 away from the second straight segment 11c, an end face of the second side plate 28 away from the second straight segment 11c, an end face of the top plate 29 away from the second straight segment 11c, and an end face of the bottom plate 30 away from the second straight segment 11c are arranged in a staggered manner.

It may be understood that in this embodiment, end faces of the first side plate 27, the second side plate 28, the top plate 29, and the bottom plate 30 away from the second straight segment 11c, i.e., end faces of the four plates at connections with the intermediate portion 12, are arranged in a staggered manner, so that the first outer straight plate 18, the first inner straight plate 19, the top plate 29 and the bottom plate 30 in the first straight segment 11a extend to different lengths at locations where a closed cavity formed jointly by the four plates is connected to the intermediate portion 12, thereby avoiding stress concentration at the connections and improving the structural strength.

In some embodiments, the arm body 1 further includes a first hinge seat 22. At least a portion of the first hinge seat 22 may be disposed at the bent segment 11b. In the bent segment 11b, the two sides of the top plate 29 along the third direction Y respectively protrude beyond the first side plate 27 and the second side plate 28, and the two sides of the bottom plate 30 along the third direction respectively protrude beyond the first side plate 27 and the second side plate 28. This not only can reduce stress concentration of the inner bent plate 17 and the outer bent plate 16 in the bent segment 11b, but also can partially conceal the first hinge seat 22, simplify the contour curve of the arm body 1, and achieve a concise and attractive appearance.

In some embodiments, the first straight segment 11a has an inner surface 23 on an inner side thereof. The inner surface 23 is specifically a side face on a side of the first inner straight plate 19 away from the first outer straight plate 18. The bent segment 11b has a bent surface 24 on an inner side thereof. The bent surface 24 is specifically a side face of the inner bent plate 17 away from the outer bent plate 16. The first hinge seat 22 is fitted against and connected to at least a portion of the inner surface 23 and is fitted against and connected to at least a portion of the bent surface 24. Exemplarily, the first hinge seat 22 is welded to an inner side of the first end portion 11, and a connecting face of the first hinge seat 22 is engaged with both the inner surface 23 and the bent surface 24, resulting in a larger welding area and more reasonable force distribution.

In some embodiments, the lifting device further includes a first crossbeam 6 and a second crossbeam 7. The first crossbeam 6 is fixedly connected between two first end portions 11 of the two sets of arm bodies 1, and the second crossbeam 7 is fixedly connected between two second end portions 13 of the two sets of arm bodies 1, so that the two sets of arm bodies 1 are connected into an integral structure to improve the stability of the lifting device.

Exemplarily, the first crossbeam 6 is disposed to extend between the two sets of arm bodies 1. Specifically, the first crossbeam 6 may be welded between the two second straight segments 11c of the two arm bodies 1. In order to improve the connection strength of the first crossbeam 6 at the second straight segment 11c, a second reinforcing plate 26 may be provided on a side of the second outer straight plate 20 close to the second inner straight plate 21 and/or on a side of the second inner straight plate 21 close to the second outer straight plate 20.

A cross-sectional shape of the first crossbeam 6 is circular, elliptical, rectangular, or irregular. Preferably, the cross-sectional shape of the first crossbeam 6 is elliptical. Compared with the rectangular or circular shape, the elliptical shape can reduce a width of the first crossbeam 6 in a front-rear direction of the entire loader (i.e., in the second direction X), and reduce shear stress on the first end portion 11 of the arm body 1 caused by the load of the loading device.

Exemplarily, the second crossbeam 7 is disposed to extend between the two sets of arm bodies 1. Specifically, the second crossbeam 7 may be welded to the second end portions 13 of the two arm bodies 1. The second crossbeam 7 may be located above a rear window of the cab 8 to avoid obstructing a driver's field of vision. The second end portion 13 includes a third side plate 31 and a fourth side plate 32 spaced apart along the third direction Y. A plurality of reinforcing plates may also be welded between the third side plate 31 and the fourth side plate 32. The reinforcing plates not only can serve to reinforce the structure, but also can provide a sealing function.

A cross-sectional shape of the second crossbeam 7 is circular, elliptical, rectangular, or irregular.

Further, in some embodiments, as shown in FIG. 9, the first connecting rod 2 is formed by welding a fifth side plate 33, a sixth side plate 34, a connecting plate 35, and a third reinforcing plate 36. The fifth side plate 33 is located on an outer side of the sixth side plate 34, and the fifth side plate 33 is a bent and inwardly retracted structure to accommodate an installation space for the fifth side plate on a vehicle frame. The third reinforcing plate 36 is welded to the fifth side plate 33, the sixth side plate 34, and the connecting plate 35 to form a box structure, thereby improving the structural strength of the first connecting rod 2.

The lifting device and the loader using the same in the present application have at least the following beneficial effects.

• • 1. By reasonably setting the positions of the hinge points between the first connecting rod 2, the second connecting rod 3 and the first driving member 4, and the frame 5 and the arm body 1, the first connecting rod 2 and the second connecting rod 3 can be as short as possible, and the rear end structure of the four-bar linkage formed can be more compact. Moreover, as the first end portion 11 of the arm body 1 adopts an inwardly retracted structure, the forward extension distance of the arm body 1 is short, which improves the stability and working capacity of the entire lifting device.
  • 2. During lifting and lowering operations of the lifting device, the first connecting rod 2 can be on the front side of the rear end of the entire loader throughout the process, and the tail end of the arm body 1 is substantially flush with the rear end of the entire loader. This improves the operational performance in narrow spaces.
  • 3. The arm body 1 adopts a three-segment structure design, providing smooth appearance while ensuring lateral visibility. The first end portion 11 and the second end portion 13 of the arm body 1 are respectively provided with the first crossbeam 6 and the second crossbeam 7, thereby enhancing the strength of the entire loader. Moreover, the second crossbeam 7 is positioned high, providing good rearward visibility. The intermediate portion 12 is an integral rectangular beam, with two ends plug-connected into the first end portion 11 and the second end portion 13, respectively. This eliminates the need to additionally provide a reinforcing plate, and achieves a simple overall structure and good reliability.

Although the embodiments of the present application are described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations fall within the scope defined by the appended claims.