Patent Description:
A boom is a commonly used device in a work machine that transports materials to a certain location. A boom assembly is typically of a multi-section structure and has a folding function, which facilitates transporting and working.

A bending portion of a conventional boom is generally located in front of an oil cylinder base. As shown in <FIG>, the boom <NUM>' has a connecting portion <NUM> and a bending portion <NUM> which are connected, and the connecting portion <NUM> is connected to the oil cylinder base. Since a distance between two ends of the boom <NUM>' is small, stress concentration is prone to occur at the bending portion <NUM> of the boom <NUM>', which brings a poor stress condition and affects the durability of the boom <NUM>'.

<CIT> describes a concrete distributing boom for stationary and mobile concrete pumps.

Therefore, there is a need to improve the above technical solution to change the current situation.

The present application aims to solve at least one of the problems existing in the existing art or the related art. This and other objects are achieved by a bending boom according to claim <NUM>.

For this, the purpose of the present application is to provide a bending boom, a boom device and a work machine to solve the problem that stress concentration is prone to occur at a bending portion of a boom in a conventional work machine, and thereby affecting the durability.

To achieve the above purpose, the technical solution according to a first aspect of the present application provides a bending boom, which includes a middle portion and two extending portions; the middle portion is configured to connect an external component; each extending portion has a first side wall and a second side wall opposite to the first side wall; the first side wall is flush with the middle portion, and the second side wall is at least partially bent from the middle portion towards a direction near the first side wall; the two extending portions are connected to two opposite ends of the middle portion, the first side walls of the two extending portions are connected to two different side walls of the middle portion, and the second side walls of the two extending portions are connected to two different side walls of the middle portion.

According to a bending boom provided by the present application, the first side wall and the second side wall of the same extending portion have separated projections on a horizontal plane.

According to a bending boom provided by the present application, a longitudinal section area of the extending portion gradually decreases from the middle portion towards a direction away from the middle portion.

According to a bending boom provided by the present application, the second side wall includes a bending section, one end of the bending section is connected to the middle portion, and the bending section is bent from the middle portion towards a direction near the first side wall.

According to a bending boom provided by the present application, the bending section is arc-shaped, and a curvature in a middle of the bending section is greater than the curvature on two sides.

According to a bending boom provided by the present application, the second side wall further includes a connecting section, the connecting section is connected to one end of the bending section away from the middle portion, and the connecting section is parallel to the first side wall.

According to a bending boom provided by the present application, the bending boom further includes an oil cylinder base, the oil cylinder base is connected to the middle portion and configured to connect an external oil cylinder.

The technical solution according to a second aspect of the present application provides a boom device, which includes a front boom, a rear boom, and any one of the bending booms described above; the front boom and the rear boom are articulated to two ends of the bending boom.

According to a boom device provided by the present application, the boom device further includes a first sectional boom; one end of the first sectional boom is configured to be articulated to a rotating platform of a vehicle body, and the other end of the first sectional boom is articulated to the front boom; the front boom is a second sectional boom, the bending boom is a third sectional boom, and the rear boom is a fourth sectional boom; the first sectional boom, the second sectional boom and a head section of the third sectional boom occupy one column of space; and the fourth sectional boom and an end section of the third sectional boom occupy another column of space.

The technical solution according to a third aspect of the present application provides a work machine, which includes the bending boom described in the first aspect or the boom device described in the second aspect.

In the bending boom of the embodiment, the bending transition of the extending portion in the bending boom is not too sharp, and the extending portions on the two sides are bent into place without bending one side into place, which brings a good stress condition and a low stress level to the extending portion. In addition, the middle portion can be made as wide as possible to provide a good structural stress and make the force transmission smooth. Besides, the bending boom in the embodiment has a larger width at the middle portion compared with a conventional boom, thereby improving the durability and strength of the bending boom.

In the bending boom of the embodiment, by providing the matching middle portion and extending portions, the bending structures in the bending boom can be staggered, and a situation in which stress concentration occurs at the middle portion can be prevented, which improves the stress condition and the durability of the bending boom.

In the boom device of the embodiment, by providing the bending boom with improved durability, the durability of the boom device is also improved and the use effect is good.

By installing the above boom device, the overall durability of the work machine in the embodiment is also improved, and the maintenance cost of the work machine is also reduced.

The additional aspects and advantages of the present application will become apparent through the following description, or become known through the practice of the present application.

The above and/or the additional aspects and advantages of the present application will become apparent and easy to understand from the descriptions of the embodiments in conjunction with the following drawings.

The corresponding relationships between the reference signs and component names in <FIG> are as follows:
<NUM>-boom device, <NUM>-bending boom, <NUM>-middle portion, <NUM>-extending portion, <NUM>-first side wall, <NUM>-second side wall, <NUM>-bending section, <NUM>-connecting section, <NUM>-top plate, <NUM>-top plate connecting portion, <NUM>-top plate bending portion, <NUM>-top plate bending section, <NUM>-top plate connecting section, <NUM>-bottom plate, <NUM>-side plate, <NUM>-side plate connecting portion, <NUM>-side plate bending portion, <NUM>-side plate bending section, <NUM>-side plate connecting section, <NUM>-oil cylinder base, <NUM>-front boom, <NUM>-rear boom.

In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with the accompanying drawings. Obviously, the embodiments to be described are only some rather than all 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 shall fall within the scope of the present application.

As shown in <FIG>, an embodiment of the present application provides a bending boom <NUM> including a middle portion <NUM> and an extending portion <NUM>. The middle portion <NUM> is used as a mounting carrier for installing external components. For example, when the bending boom <NUM> is used for a concrete pump truck, the external components can include a hydraulic cylinder, and there is no specific limit here.

Specifically, referring to <FIG> together, the extending portion <NUM> has a first side wall <NUM> and a second side wall <NUM> opposite to the first side wall <NUM>. The first side wall <NUM> is flush with the middle portion <NUM>, and the second side wall <NUM> is at least partially bent from the middle portion <NUM> towards a direction near the first side wall <NUM>. The number of the extending portion <NUM> is two, and the two extending portions <NUM> are connected to two opposite ends of the middle portion <NUM>. The first side walls <NUM> of the two extending portions <NUM> are connected to two different side walls of the middle portion <NUM>, respectively, and the second side walls <NUM> of the two extending portions <NUM> are connected to two different side walls of the middle portion <NUM>, respectively. In some embodiments, the two extending portions <NUM> can be centrally symmetrical about the middle portion <NUM>. The middle portion <NUM> can be of a linear type, that is, the middle portion <NUM> at least partially extends along a straight direction.

In the bending boom <NUM> of the above embodiment, the middle portion <NUM> is used for connecting external components such as an oil cylinder base <NUM>. By arranging the two extending portions <NUM> at two opposite ends of the middle portion <NUM> symmetrically, a situation in which stress concentration occurs in the part of the bending boom <NUM> with which external components are connected can be prevented. Meanwhile, by providing the extending portion <NUM> with one of the side walls being flush with the middle portion <NUM>, the bending boom <NUM> in this embodiment has a larger width at the middle portion <NUM> compared with a conventional boom, thereby improving the durability of the bending boom <NUM>.

In the bending boom <NUM> of the above embodiment, by providing the matching middle portion <NUM> and extending portions <NUM>, the bending structures in the bending boom <NUM> can be staggered, and a situation in which stress concentration occurs at the middle portion <NUM> can be prevented, which improves the stress condition and the durability of the bending boom <NUM>.

As shown in <FIG>, in an embodiment, projections of the first side wall <NUM> and the second side wall <NUM> of the same extending portion <NUM> on a horizontal plane are arranged separately.

By this arrangement, the first side wall <NUM> and the second side wall <NUM> can be arranged at two opposite sides of the bending boom <NUM> in a horizontal direction, which enables the bending boom <NUM> to fully utilize the surrounding space while connecting to other sectional booms and provides a compact structure. In other embodiments, the first side wall <NUM> and the second side wall <NUM> can also be arranged in a vertical direction, and by doing so, the whole structure can be arranged in the horizontal direction when the bending boom <NUM> is connected to other sectional booms.

Further, as shown in <FIG> and <FIG>, a longitudinal section area of the extending portion <NUM> gradually decreases from the middle portion <NUM> towards a direction away from the middle portion <NUM>. Specifically, in an embodiment, as shown in <FIG>, the width of the extending portion <NUM> in a left and right direction gradually decreases from the middle portion <NUM> towards the direction away from the middle portion <NUM>. The decrease can be intermittent, or can be continuous as shown in <FIG>. Referring to <FIG>, the height of every part of the extending portion <NUM> is equal in an up and down direction.

In an embodiment, a small end of the extending portion <NUM> can be used to connect other sectional booms, and the middle portion <NUM> can be used to connect external components such as an oil cylinder. By doing so, the bending boom <NUM> can have a larger section size at the middle portion <NUM> to increase the overall strength of the bending boom <NUM>. The bending of the extending portion <NUM> can not cause a problem that stress concentration occurs to the bending boom <NUM>, which brings a good use effect.

As shown in <FIG> and <FIG>, in an embodiment, the second side wall <NUM> includes a bending section <NUM>, one end of the bending section <NUM> is connected to the middle portion <NUM>, and the bending section <NUM> is bent from the middle portion <NUM> towards a direction near the first side wall <NUM>.

In an embodiment, the second side wall <NUM> can only be provided with the bending section <NUM>, and one end of the bending section <NUM> away from the middle portion <NUM> can be used to connect other external components.

Specifically, the bending section <NUM> is arc-shaped, and a curvature in a middle of the bending section <NUM> is greater than the curvature on both sides.

As shown in <FIG>, in an embodiment, by providing the arc-shaped bending section <NUM>, the side wall of the middle portion <NUM> and one end of the bending section <NUM> away from the middle portion <NUM> can be staggered, so that the bending boom <NUM> and a number of external sectional booms can be staggered when they are connected, therefore, the effects of compacting the structure and saving space can be achieved. In other embodiments, the sectional profile of the bending section <NUM> can also be a straight line, and there is no need to describe them in detail here.

Further, the second side wall <NUM> further includes a connecting section <NUM>, the connecting section <NUM> is connected to one end of the bending section <NUM> away from the middle portion <NUM>, and the connecting section <NUM> is parallel to the first side wall <NUM>.

As shown in <FIG>, in an embodiment, the bending sections <NUM> in the two sets of extending portions <NUM> are located at two opposite ends of the middle portion <NUM>, respectively. Compared with the conventional boom <NUM>', in an embodiment, the bending transition of the extending portion <NUM> in the bending boom <NUM> is not too sharp, and the extending portions <NUM> on the two sides are bent into place without bending one side into place, which brings a good stress condition and a low stress level to the extending portion <NUM>. In addition, the middle portion <NUM> can be made as wide as possible to provide a good structural stress and make the force transmission smooth when connected to an oil cylinder through the oil cylinder base <NUM>. Referring to the placement shown in <FIG>, the middle portion <NUM> can be set a corresponding width according to practical design requirements, and the width size of the middle portion <NUM> cannot be affected by the bending structure, it is possible to ensure the strength of the middle portion <NUM> itself, and further the strength of the bending boom <NUM>. The structure is simple and the use effect is good. In another embodiment, an angle can be formed between an extension direction of the connecting section <NUM> and the extension direction of the first side wall <NUM>, and there is no limit here.

As shown in <FIG>, in an embodiment, the bending boom <NUM> includes a top plate <NUM>, a bottom plate <NUM>, and a side plate <NUM>. The top plate <NUM> and the bottom plate <NUM> are provided parallel to each other and with intervals. The side plate <NUM> includes a side plate connecting portion <NUM> and a side plate bending portion <NUM> which are connected. The side plate connecting portion <NUM> is connected between the top plate <NUM> and the bottom plate <NUM> to form the middle portion <NUM>. The side plate bending portion <NUM> is connected between the top plate <NUM> and the bottom plate <NUM> to form the extending portion <NUM>.

In an embodiment, the bending boom <NUM> is mainly composed of the top plate <NUM>, the bottom plate <NUM> and the side plate <NUM>. The side plate bending portion <NUM> can be formed by bending the side plate <NUM>, and the bending boom <NUM> can be formed when the side plate <NUM>, the top plate <NUM> and the bottom plate <NUM> are connected. The extending portion <NUM> can form a support structure inside the bending boom <NUM> along the direction in which the extending portion <NUM> is bent to ensure the strength of the bending boom <NUM>.

It should be noted that, the top plate <NUM> can have the same shape as the bottom plate <NUM>, which saves the cost of molds in the machining process. In some embodiments, the top plate <NUM> and the bottom plate <NUM> can also be configured as corresponding shapes according to practical requirements, and there is no limit here.

Specifically, as shown in <FIG>, the top plate <NUM> includes a top plate connecting portion <NUM> and a top plate bending portion <NUM> which are connected. The top plate bending portion <NUM> includes a top plate bending section <NUM> and a top plate connecting section <NUM> which are connected. The top plate bending section <NUM> is connected to the top plate connecting section <NUM> and the top plate connecting portion <NUM>, respectively. The side plate bending portion <NUM> includes a side plate bending section <NUM> and a side plate connecting section <NUM> which are connected, and the side plate bending section <NUM> is connected to the side plate connecting section <NUM> and the side plate connecting portion <NUM>, respectively.

In an embodiment, the side plate bending section <NUM> is connected to the top plate bending section <NUM> and the bottom plate <NUM> to form the bending section <NUM>, respectively. The side plate connecting section <NUM> is connected to the top plate connecting section <NUM> and the bottom plate <NUM> to form the connecting section <NUM>, respectively.

As shown in <FIG>, in an embodiment, two second side walls <NUM> are centrally symmetrical about the middle portion <NUM>, that is, when the second side wall <NUM> at least partially extends along a straight line, at least a part of the two second side walls <NUM> are parallel to each other. In other embodiments, the two second side walls <NUM> can also be arranged not centrally symmetrical, for example, as shown in <FIG>, a certain angle can be formed between profile lines of the two second side walls <NUM>, and an opening direction of the angle can face upwards or downwards in the vertical direction.

Specifically, in an embodiment, the side plate <NUM> is connected to the top plate <NUM> and the bottom plate <NUM> by welding, respectively.

In the machining process, the two opposite ends of the side plate <NUM> can be welded to the top plate <NUM> and the bottom plate <NUM> to form the bending boom <NUM>, which ensures the strength of the bending boom <NUM>. In other embodiments, the side plate <NUM>, the top plate <NUM> and the bottom plate <NUM> can be connected by detachable connections, such as screw connection, snap-fit connection, plug-fit connection, rivet connection or other connections.

Specifically, in an embodiment, the number of the side plate <NUM> is two, and the two side plates <NUM> are both disposed between the top plate <NUM> and the bottom plate <NUM> and are centrally symmetrical about the middle portion <NUM>.

In an embodiment, by connecting the top plate <NUM> and the bottom plate <NUM> with the two side plates <NUM>, a hollow box structure can be enclosed and formed whose section is rectangular. Compared to a boom with a solid interior, the bending boom <NUM> in the embodiment can reduce the total weight of the bending boom <NUM> in the precondition of ensuring the strength of the bending boom <NUM>, which facilitates the light weight, transportation, assembly and use.

As shown in <FIG>, in an embodiment, edges of the top plate <NUM> and the bottom plate <NUM> are a combination of straight lines and arcs, and are matched with the profile of a side surface of the side plate <NUM>. In the assembly process, the positioning can be realized by the edge of the top plate <NUM> and the surface of the side plate <NUM>, and after the side plate <NUM> is connected to the top plate <NUM> and the bottom plate <NUM>, neat joint seams exist between two neighboring parts, which brings the bending boom <NUM> a coherent appearance.

In some embodiments shown in <FIG> and <FIG>, the number of the extending portion <NUM> is two, and the two extending portions <NUM> are connected to two opposite ends of the middle portion <NUM>, respectively. The connecting sections <NUM> of the two extending portions <NUM> have the same section area.

In an embodiment, the connecting sections <NUM> on the two opposite ends of the middle portion <NUM> have the same width size, and two sets of the connecting sections <NUM> have the same section area, which makes the force transmission smooth on the bending boom <NUM>. In other embodiments, the two sets of the connecting sections <NUM> can have different section area, and there is no limit here.

As shown in <FIG>, the present application further provides a boom device <NUM>. The boom device <NUM> includes the bending boom <NUM> described in any one of the above embodiments.

It can be understood that, in the boom device <NUM> according to the present application, by providing the bending boom <NUM> with improved durability, the durability of the boom device <NUM> is also improved and the use effect is good.

Specifically, in an embodiment, the boom device <NUM> further includes a front boom <NUM> and a rear boom <NUM>, the front boom <NUM> and the rear boom <NUM> are flexibly connected to two opposite ends of the bending boom <NUM>, and the front boom <NUM> is parallel to the rear boom <NUM>.

In an embodiment, the front boom <NUM> and the rear boom <NUM> respectively connected to two opposite ends of the bending boom <NUM> are provided. Referring to the placement shown in <FIG>, when the boom device <NUM> is in a folded state, the front boom <NUM> and the rear boom <NUM> can be staggered by the extending portions <NUM> provided by the bending boom <NUM>, which facilitates the arrangement of two or more columns of the boom devices <NUM>.

In some embodiments, the boom device <NUM> can further include a first sectional boom (not shown in the drawings), one end of the first sectional boom is used to articulate to a rotating platform of a vehicle body, and the other end of the first sectional boom is articulated to the front boom <NUM>. The front boom <NUM> is a second sectional boom, the bending boom <NUM> is a third sectional boom, and the rear boom <NUM> is a fourth sectional boom. When folding the boom device <NUM>, the first sectional boom, the front boom <NUM> and a head section of the bending boom <NUM> occupy the space located on one side of the bending boom <NUM> and are capable of moving in the space, while the rear boom <NUM> and an end section of the bending boom <NUM> occupy the space located on the other side of the bending boom <NUM> and are capable of moving in the space, which helps to reduce the overall height of the boom device <NUM>. In other embodiments of the present application, the boom device <NUM> can further include a fifth sectional boom, a sixth sectional boom, and so on, and there is no limit to the number of booms.

In this way, by arranging the first, second, third, and fourth sectional booms, the boom device <NUM> can have a more compact structure in the precondition of meeting the requirement that the boom device <NUM> has a larger extension size, which reduces the space occupied by the boom device <NUM> and facilitates the arrangement and installation of the boom device <NUM> on vehicles. In other embodiments, the above bending boom <NUM> can also be the fourth sectional boom, and there is no limit here.

Further, the present application further provides a work machine, and the work machine includes the boom device <NUM> described in any one of the above embodiments. It can be understood that, by installing the above boom device <NUM>, the overall durability of the work machine in the embodiment is also improved, and the maintenance cost of the work machine is also reduced. In an embodiment, the work machine can be, for example, a concrete pump truck or a fire fighting truck, or the like.

In an embodiment, the work machine further includes a hydraulic oil pipe (not shown in the drawings), and the hydraulic oil pipe is at least partially threaded through the middle portion <NUM> and the extending portion <NUM>.

In an embodiment, the hydraulic oil pipe can be threaded into the bending boom <NUM> through the side plate bending section <NUM> on one side, and threaded out through the side plate bending section <NUM> on the other side. By doing so, the hydraulic oil pipe can be fixed by the bending boom <NUM>, and since the middle portion <NUM> is always in a relatively fixed state with the hydraulic oil pipe during the unfolding process of the bending boom <NUM>, a problem that the hydraulic oil pipe may be stretched to be broken during the unfolding process of the bending boom <NUM> can be prevented, in order to protect the hydraulic oil pipe. In addition, the boom device <NUM> can have a more compact structure, which facilitates the installation and arrangement, the structure is simple, and the use effect is good.

Claim 1:
A bending boom (<NUM>), characterized by comprising:
a middle portion (<NUM>) configured to connect an external component; and
two extending portions (<NUM>), each of the two extending portions having a first side wall (<NUM>) and a second side wall (<NUM>) opposite to the first side wall (<NUM>), wherein the first side wall (<NUM>) is flush with the middle portion (<NUM>), and the second side wall (<NUM>) is at least partially bent from the middle portion (<NUM>) towards a direction near the first side wall (<NUM>);
wherein the two extending portions (<NUM>) are connected to two opposite ends of the middle portion (<NUM>), the first side walls (<NUM>) of the two extending portions (<NUM>) are connected to two different side walls of the middle portion (<NUM>), and the second side walls (<NUM>) of the two extending portions (<NUM>) are connected to two different side walls of the middle portion (<NUM>).