JP6869606B2 - Maintenance window opening / closing mechanism - Google Patents

Description

The present invention relates to a maintenance window opening / closing mechanism, and more particularly to a maintenance window opening / closing mechanism for opening / closing a maintenance window provided on a counterweight of a construction machine with an opening / closing cover.

In construction machinery such as hydraulic excavators, the engine, hydraulic equipment, etc. provided inside the engine room are regularly or when necessary. In construction machinery, maintenance windows for servicing engines and hydraulic equipment are formed on the outer wall surface of the engine room and counterweights. Workers reach out to the engine, hydraulic pump, etc. mounted in the engine room from the maintenance window to perform maintenance work. Various types of maintenance window opening / closing mechanisms have been proposed. Among them, an opening / closing mechanism for opening / closing a maintenance window formed on a counterweight with an opening / closing cover has been proposed.

For example, in the maintenance window opening / closing mechanism proposed in Patent Document 1, a maintenance window for servicing an engine is formed on a counterweight, and an opening / closing cover for opening / closing the maintenance window is provided by a link mechanism. I'm moving it. One end of each link constituting the link mechanism in the longitudinal direction is supported on the counterweight side, and the other end is supported on the open / close cover side. The opening / closing cover opens / closes the maintenance window by being moved up and down by the link mechanism. In this maintenance window opening / closing mechanism, in order to prevent the opening / closing cover from interfering with the rear part of the operator cabin when the cover is moved upward, the link is attached to the position where the link is supported on the counterweight side or to the opening / closing cover. The position is devised so that the upper part of the cover tilts backward from the lower part when the open / close cover is opened.

Japanese Unexamined Patent Publication No. 2009-154755

When servicing an engine or flood control equipment, there is no problem in any form of opening and closing the open / close cover as long as the machine can be brought into a maintenance shop with a large site area for maintenance. However, it may be necessary to open the open / close cover for maintenance in a place where only a narrow space can be secured. In this case, in the maintenance window opening / closing mechanism in which the counterweight is provided with a maintenance window, the opening / closing cover slides open along the outer surface of the counterweight rather than the door structure in which the opening / closing cover opens outward from the counterweight. The structure is desired. In this respect, the opening / closing cover moving mechanism proposed in Patent Document 1 moves the opening / closing cover up and down along the outer surface of the counterweight. Therefore, it is convenient in that the maintenance window can be opened and closed even when there is no large space behind the counterweight.

However, the maintenance window opening / closing mechanism proposed in Patent Document 1 is in the form of moving the cover upward to open it. Therefore, this maintenance window opening / closing mechanism puts a burden on the operator when the opening / closing cover is moved upward to open the maintenance window. In addition, since the weight of the opening / closing cover is applied to the link mechanism and the spring, the maintenance window opening / closing mechanism itself is also loaded. In the unlikely event that the spring that constitutes the opening / closing mechanism is damaged, the opening / closing cover that has moved upward may drop. Furthermore, when the opening / closing cover is moved upward, the upper part of the opening / closing cover tilts diagonally toward the rear of the counterweight, so that the opening / closing cover interferes with the maintenance work depending on the posture when the operator performs maintenance. Sometimes.

The present invention has been made to solve the above problems, and an object of the present invention is a maintenance window opening / closing mechanism that can safely open / close the opening / closing cover and secure a sufficient work space for an operator. Is to provide.

The maintenance window opening / closing mechanism according to the present invention for solving the above problems is formed on a counter weight attached to the rear part of the construction machine, and the inside where the drive device of the construction machine is provided and the outside of the construction machine. It is a maintenance window opening / closing mechanism for opening / closing the maintenance window that connects the above, and the opening / closing cover that opens / closes the maintenance window, the opening / closing cover and the counter weight are connected by a plurality of links, and the opening / closing is performed. A link mechanism for moving the cover horizontally with respect to the counter weight and a spring provided for the link mechanism are provided, and the link mechanism can rotate the link with respect to the counter weight. Each end of the counter weight side in the longitudinal direction is supported, the first fixed support portion and the second fixed support portion arranged side by side in the horizontal direction are provided, and the link can be rotated with respect to the opening / closing cover. The other end of the opening / closing cover side in the longitudinal direction of the link is supported, and the first moving support portion and the second moving support portion arranged side by side in the horizontal direction are provided, and the first fixed support portion and the first moving portion are provided. The support portion is connected by the first link, the second fixed support portion and the second moving support portion are connected by the second link, and the first fixed support portion and the second fixed support portion are connected to each other. The distance is set to be smaller than the distance between the first moving support portion and the second moving support portion, and the spring has one end in the longitudinal direction at the same position as the second fixed support portion, or the second link. It is supported at a position between the central portion and the second fixed support portion in the longitudinal direction, the other end is between the first moving support portion and the second moving support portion, and the opening / closing cover is the maintenance. It is characterized in that it is supported by a second link on the inner side of the construction machine rather than the first moving support portion and the second moving support portion in a closed form.

According to the present invention, the first fixed support portion, the second fixed support portion, the first moving support portion and the second moving support portion are arranged horizontally, and the first fixed support portion and the first moving support portion are first. Since the second fixed support portion and the second moving support portion are connected by the second link while being connected by the link, the opening / closing cover moves in the horizontal direction. Therefore, when the opening / closing cover is opened, the opening / closing cover can be moved to the side of the maintenance window. Further, since the distance between the first fixed support portion and the second fixed support portion is set to be smaller than the distance between the first moving support portion and the second moving support portion, it opens and closes when the opening / closing cover is opened. The end on the closing direction, which is the closing direction of the cover, is located farther from the counterweight than the end on the opening direction, which is the opening direction of the opening / closing cover. As a result, a large space is formed behind the maintenance window. Further, since the opening / closing cover is moved in the horizontal direction, the opening / closing cover will not be closed even if the link mechanism or the spring is damaged when the opening / closing cover is open. As a result, the operator is not caught between the opening / closing cover and the counterweight, and the work can be performed safely.

In the maintenance window opening / closing mechanism according to the present invention, the first fixed support portion and the first moving support portion have the opening / closing cover of the maintenance window rather than the second fixed support portion and the second moving support portion. Is arranged on the open direction side, which is the direction of moving from the closed form to the open form, and the first link is shorter than the second link.

According to the present invention, since the first link is shorter than the second link, in the form in which the opening / closing cover is completely opened, the opening / closing cover is forcibly tilted diagonally with respect to the counterweight, and the end on the maintenance window side. The portion is positioned at a position farther from the counterweight than the end on the opening direction side. Therefore, a large work space is formed in the vicinity of the maintenance window.

In the maintenance window opening / closing mechanism according to the present invention, in the form in which the opening / closing cover closes the maintenance window, the first fixed support portion, the second fixed support portion, the first movement support portion, and the second movement The support portion is arranged linearly in the horizontal direction.

According to the present invention, the first fixed support portion, the second fixed support portion, the first moving support portion, and the second moving support portion are arranged linearly in the horizontal direction in a form in which the opening / closing cover closes the maintenance window. Therefore, when the opening / closing cover closes the maintenance window, the area occupied by the link mechanism inside the maintenance window can be reduced. Therefore, it is possible to prevent interference with various devices provided inside the machine body, and it is possible to increase the degree of freedom in arranging various devices such as valves inside the machine body.

In the maintenance window opening / closing mechanism according to the present invention, the second link is formed with a spring support that projects from the opening / closing cover side in the longitudinal direction to the closing direction side in which the opening / closing cover closes, and the other end of the spring. Is attached to the spring support.

According to the present invention, in the range from the form in which the opening / closing cover closes the maintenance window to a position separated by a predetermined distance, a link mechanism provided with a spring applies a force in the direction of closing the opening / closing cover, and a predetermined position is provided. A link mechanism with a spring exerts a force in the opening direction of opening the opening / closing cover in a range further away than the position separated by a distance. Therefore, the opening / closing cover can be easily opened / closed.

In the maintenance window opening / closing mechanism according to the present invention, a pair of upper and lower link mechanisms are provided, and the first fixed support portion and the second fixed support portion arranged on the upper side are provided above the maintenance window. The first moving support portion and the second moving support portion are attached to the upper side of the opening / closing cover, and the first fixed support portion and the second fixed support portion arranged on the lower side are the lower part of the maintenance window. The first moving support portion and the second moving support portion are attached to the lower side of the opening / closing cover.

According to the present invention, since the link mechanisms are provided on the upper side and the lower side, the opening / closing cover can be stably supported with respect to the counterweight.

According to the present invention, the safety cover can be safely opened and closed, and a sufficient work space for the operator can be secured.

It is a side view of the hydraulic excavator which is an example of the construction machine to which the maintenance window opening / closing mechanism which concerns on this invention is applied. It is a perspective view of the maintenance window opening / closing mechanism which concerns on this invention. It is a top view of the maintenance window opening / closing mechanism which concerns on this invention. It is the schematic which showed the link mechanism provided with a spring as a model. It is explanatory drawing for demonstrating the state which the opening / closing cover moves from the closed form to the open form of a maintenance window. It is a perspective view for demonstrating the form in which the opening / closing cover is closed and the form in which the maintenance window is opened.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention includes inventions having the same technical ideas as those described in the embodiments and drawings described below, and the technical scope of the present invention is limited to the description of the embodiments and the drawings. Not. The construction machine to which the present invention is applied is not particularly limited, but the hydraulic excavator 1 will be described below as an example.

[Overview of hydraulic excavator]
As shown in FIG. 1, the hydraulic excavator 1 is composed of a machine main body 2 and a work unit 15 extending forward from the machine main body 2. The machine main body 2 forms a lower portion thereof, and is composed of a traveling body 3 traveling on the machine main body 2 and a rotating body 7 capable of turning horizontally with respect to the traveling body 3. The traveling body 3 is mainly provided with a traveling frame 4, a crawler 5, and a motor 6 that transmits a driving force to the crawler 5. The swivel body 7 has an operator cabin 8 for the operator to sit down and operate the hydraulic excavator 1, an engine room 9 for internally providing an engine, hydraulic equipment, and the like, and for balancing the machine at the rear. A counter weight 10 is provided. On the other hand, the work unit 15 is composed of a boom 16 extending forward from the swivel body 7, an arm 17 supported by the tip of the boom 16, and a bucket 18 supported by the tip of the arm 17.

The maintenance window opening / closing mechanism 20 according to the present invention is provided on a counterweight 10 arranged at the rear of the swivel body 7. That is, a maintenance window 11 that connects the inside where the drive device of the hydraulic excavator 1 is provided and the outside of the hydraulic excavator 1 is formed on the counterweight 10, and the opening / closing cover 12 that opens and closes the maintenance window 11. Is connected to the counterweight 10 by the maintenance window opening / closing mechanism 20.

[Basic configuration of the present invention]
As shown in FIGS. 2 to 4, the maintenance window opening / closing mechanism 20 according to the present invention connects the opening / closing cover 12 that opens / closes the maintenance window 11 and the opening / closing cover 12 and the counterweight 10 with a plurality of links 21 and 22. A link mechanism 20A for moving the opening / closing cover 12 in the horizontal direction with respect to the counterweight 10 and a spring 40 provided on the link mechanism 20A are provided. The link mechanism 20A includes a first fixed support portion 25, a second fixed support portion 26, a first moving support portion 27, and a second moving support portion 28. The first fixed support portion 25 and the second fixed support portion 26 are arranged so that the links 21 and 22 can rotate the ends 21a and 22a on the counterweight 10 side in the longitudinal direction of the links 21 and 22 with respect to the counterweight 10. They support each and are arranged side by side in the horizontal direction. On the other hand, in the first moving support portion 27 and the second moving support portion 28, the links 21 and 22 can rotate the other ends 21b and 22b on the opening / closing cover 12 side in the longitudinal direction of the link 21.22 with respect to the opening / closing cover 12. I support it so that it becomes. The first fixed support portion 25 and the first moving support portion 27 are connected by a first link 21, and the second fixed support portion 26 and the second moving support portion 28 are connected by a second link 22. The distance L1 between the first fixed support portion 25 and the second fixed support portion 26 is set smaller than the distance L2 between the first moving support portion 27 and the second moving support portion 28.

The spring 40 is supported at one end 40a in the longitudinal direction at the same position as the second fixed support portion 26, or at a position between the central portion and the second fixed support portion 26 in the longitudinal direction of the second link 22, and the other end 40b. Is between the first moving support part 27 and the second moving support part 28, and the construction machine 1 is more than the first moving support part 27 and the second moving support part 28 in the form in which the opening / closing cover 12 maintenance window is closed. It is attached to the second link 22 on the inner side of the. However, in the following specific embodiment, a case where one end 40a in the longitudinal direction is supported at a position between the central portion and the second fixed support portion 26 in the longitudinal direction of the second link 22 will be described as an example. There is.

According to the maintenance window opening / closing mechanism 20 according to the present invention, the opening / closing cover 12 can be safely opened and closed, and a unique effect that a sufficient work space for the worker H can be secured can be obtained. Hereinafter, each configuration of the present invention will be specifically described.

(Opening and closing cover)
As shown in FIGS. 2 and 3, the opening / closing cover 12 is composed of plate-shaped members that are horizontally long in the horizontal direction, specifically, in the left-right direction. The opening / closing cover 12 of the example shown in FIGS. 2 and 3 is curved in the horizontal direction and has an arc shape. The degree of curvature of the opening / closing cover 12 is formed according to the degree of curvature of the counterweight 10. The convexly formed surface of the opening / closing cover 12 is directed to the outside of the machine body 2, and the concave surface is directed to the inside of the machine body 2. However, the opening / closing cover 12 may be formed of a flat plate-shaped member without being curved. The link mechanism 20A constituting the maintenance window opening / closing mechanism 20 is attached to the inner surface of the opening / closing cover 12. The link mechanism 20A is attached to the central portion of the opening / closing cover 12 in the left-right direction via a bracket 32 described later. Therefore, the opening / closing cover 12 is maintained in a well-balanced form on the left and right by the link mechanism 20A.

(Link mechanism and spring)
The link mechanism 20A has two links 21 and 22, and each link 21 and 22 connects the counterweight 10 side and the opening / closing cover 12 side. The longitudinal ends 21a and 22a of the links 21 and 22 are supported by the mounting bracket 31 attached to the counterweight 10, and the other ends 21b and 22b in the longitudinal direction are supported by the bracket 32 attached to the opening / closing cover 12. Has been done. One link mechanism 20A is provided on the upper and lower sides, and each link mechanism 20A is supported by a counterweight 10 via a mounting bracket 31 at an upper portion and a lower portion of the opening / closing cover 12, respectively. Since the link mechanism 20A provided on the upper side and the link mechanism 20A provided on the lower side have the same configuration, the configuration of the link mechanism 20A provided on the upper side will be described below as a representative example.

As shown in FIG. 2, the mounting bracket 31 utilizes holes 31a formed one by one at the top and bottom, and is fixed to the counterweight 10 by bolts (not shown). The four holes 31b formed in the mounting bracket 31 are used, for example, for fixing the tool box. The mounting bracket 31 is provided with a first fixed support portion 25 and a second fixed support portion 26 for supporting the ends 21a and 22a of the links 21 and 22 at two locations in the horizontal direction. The first fixed support portion 25 and the second fixed support portion 26 are arranged side by side on the left and right sides. Similarly, the bracket 32 is provided with a first moving support portion 27 and a second moving support portion 28 for supporting the other ends 21b and 22b of the links 21 and 22 at two locations in the horizontal direction. The first fixed support portion 25 and the first moving support portion 27 are connected by a first link 21, and the second fixed support portion 26 and the second moving support portion 28 are connected by a second link 22. There is.

The first fixed support portion 25, the first moving support portion 27, and the first link 21 are located on the opening direction P side in which the opening / closing cover 12 opens in the moving direction of the opening / closing cover 12, and the second fixed support portion 26, the second The movement support portion 28 and the second link 22 are located on the closing direction Q side in which the opening / closing cover 12 closes the maintenance window 11 in the moving direction of the opening / closing cover 12. That is, the first fixed support portion 25 and the first moving support portion 27 are in a form in which the opening / closing cover 12 is opened from the closed state of the maintenance window 11 rather than the second fixed support portion 26 and the second moving support portion 28. They are arranged on the opening direction P side, which is the moving direction. In the maintenance window opening / closing mechanism 20, the distance L1 between the first fixed support portion 25 and the second fixed support portion 26 is set smaller than the distance L2 between the first moving support portion 27 and the second moving support portion 28. ing. That is, the following equation (Equation 1) holds.

L1 <L2 ... (Equation 1)

As described above, the first link 21 and the second link 22 connect the mounting bracket 31 attached to the counterweight 10 and the bracket 32 attached to the opening / closing cover 12, respectively. In the maintenance window opening / closing mechanism 20, the first link 21 is formed shorter than the second link 22. That is, when the length of the first link 21 is L3 and the length of the second link 22 is L4, the following (Equation 2) is established.

L3 <L4 ... (Equation 2)

In this case, the length L3 of the first link 21 is set to the center of the pin hole on the one end 21a side formed to support the pin on the first fixed support portion 25 and to support the pin on the first moving support portion 27. It is the distance from the center of the formed pin hole on the other end 21b side. Similarly, the length L4 of the second link 22 is set to the center of the pin hole on the one end 22a side formed for pin support to the second fixed support portion 26 and to pin support the second moving support portion 28. It is the distance from the center of the formed pin hole on the other end 22b side.

The first link 21 is composed of a flat elongated rod-shaped member, and both ends 21a and 21b in the longitudinal direction form a semicircle. The above pin holes are formed at both ends of the first link 21 in the longitudinal direction. A support pin 50 is passed through a pin hole formed at one end 21a in the longitudinal direction of the first link 21 and is connected to a mounting bracket 31 attached to a counterweight 10. On the other hand, a support pin 50 is passed through a pin hole formed in the other end 21b of the first link 21 in the longitudinal direction and connected to a bracket 32 attached to the opening / closing cover 12. The first link 21 is rotatably supported with respect to the mounting bracket 31 around the support pin 50, and is rotatably supported with respect to the bracket 32 around the support pin 50.

The second link 22 is composed of a flat elongated rod-shaped member. One end 22a in the longitudinal direction of the second link 22 is formed in a semicircular shape, while the other end 22b side in the longitudinal direction is formed with a spring support 23 projecting in a triangular shape toward the closing direction Q side. ing. When the opening / closing cover 12 closes the maintenance window, the apex of the spring support 23 is located between the first moving support 27 and the second moving support 28 in the longitudinal direction of the second link 22. There is. At this apex, a mounting pin 51 projecting toward the counterweight 10 side is provided. The mounting pin 51 is a portion to which the other end 40b of the spring 40, which will be described later, is mounted.

As the spring 40, a vine winding spring is used. Hooks are provided at both ends of the spring 40 in the longitudinal direction. One end 40a in the longitudinal direction is the position between the central portion of the second link 22 in the longitudinal direction and the second fixed support portion 26, in other words, the central side in the longitudinal direction of the second link 22 with respect to the second fixed support portion 26. It is attached to the attachment pin 52 of the second link 22 by a hook at the position (see FIG. 4). However, one end 40a of the spring 40 may be attached at the same position as the second fixed support portion 26. That is, the position where one end 40a of the spring 40 is attached is the same as the second fixed support portion 26 or the second link if the spring 40 can be attached so as not to interfere with surrounding objects when opening and closing the opening / closing cover 12. It may be either the position between the central portion and the second fixed support portion 26 in the longitudinal direction of 22. On the other hand, the other end 40b of the spring 40 is attached by a hook to the attachment pin 51 provided at the apex of the spring support 23 formed on the other end 22b side of the second link 22. When the opening / closing cover 12 closes the maintenance window, the mounting pin 51 is between the first moving support portion 27 and the second moving support portion 28, and the first moving support portion 27 and the second moving support portion 27 are provided. It is located on the inner side of the construction machine 1 with respect to the part 28. Therefore, when the opening / closing cover 12 closes the maintenance window, the other end 40b of the spring 40 is between the first moving support portion 27 and the second moving support portion 28, and the first moving support portion 27 and the first moving support portion 27 It is supported by the spring support 23 of the second link 22 on the inner side of the construction machine 1 with respect to the second moving support portion 28.

The spring 40 reverses the direction of the force applied to the opening / closing cover 12 on the way of the opening / closing cover 12 moving from the closed form to the completely open form of the maintenance window 11. Specifically, in the range from the form in which the opening / closing cover 12 closes the maintenance window 11 to the point where the opening / closing cover 12 moves by a certain distance, the spring 40 applies a force to the closing direction Q in which the opening / closing cover 12 closes the maintenance window 11. ing. On the other hand, in the range beyond the point where the opening / closing cover 12 has moved by a certain distance from the form in which the maintenance window 11 is closed, the spring 40 applies a force to the opening direction P in which the opening / closing cover 12 opens.

The maintenance window opening / closing mechanism 20 of the present embodiment has been described above based on the configuration of the link mechanism 20A and the spring 40 provided on the upper side among the link mechanism 20A and the spring 40 provided in pairs on the upper and lower sides. However, in the maintenance window opening / closing mechanism 20 of the present embodiment, the link mechanism 20A and the spring 40 are provided at the top and bottom, respectively. Specifically, in the maintenance window opening / closing mechanism 20, the first fixed support portion 25 and the second fixed support portion 26 of the link mechanism 20A arranged on the upper side are provided above the maintenance window 11 and the first moving support portion. The 27 and the second moving support portion 28 are attached to the upper side of the opening / closing cover 12 via the bracket 32. Further, the first fixed support portion 25 and the second fixed support portion 26 of the link mechanism 20A arranged on the lower side are provided at the lower part of the maintenance window 11, and the first moving support portion 27 and the second moving support portion 28 are provided. It is attached to the lower side of the opening / closing cover 12 via the bracket 32.

[Specific action of the maintenance window opening / closing mechanism]
The maintenance window opening / closing mechanism 20 having the above configuration operates as shown in FIGS. 5 (A) to 5 (D). In FIGS. 5 (A) to 5 (D), the upper side of each figure represents the rear side of the hydraulic excavator 1, and the lower side of each figure represents the front side of the hydraulic excavator 1.

FIG. 5A shows a form in which the maintenance window 11 is closed by the opening / closing cover 12. In the form in which the opening / closing cover 12 closes the maintenance window 11, the longitudinal direction of the first link 21 and the longitudinal direction of the second link 22 coincide with each other, and both overlap. Focusing on each of the support portions 25, 26, 27, 28 in this form, in the form in which the opening / closing cover 12 closes the maintenance window 11, the first fixed support portion 25, the second fixed support portion 26, and the first movement The support portion 27 and the second moving support portion 28 are arranged linearly in the horizontal direction. Specifically, the first fixed support portion 25 and the second fixed support portion 26 are arranged on the opening direction P side (right side in the drawing) with respect to the first moving support portion 27 and the second moving support portion 28, respectively. In the first link 21 and the second link 22, one ends 21a and 22a of the first link 21 and the second link 22 are supported by the first fixed support portion 25 and the second fixed support portion 26, and the other ends 21b and 22b of the first link 21 and the second link 22 are in the closing direction Q (in the figure). It extends horizontally toward the left side). The other ends 21b and 22b of the first link 21 and the second link 22 are supported by the first moving support portion 27 and the second moving support portion 28, respectively. Further, the spring support 23 formed on the other end 22b side of the second link 22 projects toward the closing direction Q side (lower side in the figure).

In the maintenance window opening / closing mechanism 20 of the present embodiment, when the maintenance window 11 is closed by the opening / closing cover 12, the first fixed support portion 25, the second fixed support portion 26, the first movement support portion 27, and the second movement Since the support portion 28 is arranged linearly in the horizontal direction and the first link 21 and the second link 22 overlap each other, the area occupied by the link mechanism 20A can be reduced.

FIG. 5B shows a form in which the maintenance window 11 is opened and the opening / closing cover 12 is in the process of moving. FIG. 5B shows a position where the direction of the force applied to the opening / closing cover 12 by the link mechanism 20A provided with the spring 40 is reversed. That is, when the opening / closing cover 12 is located closer to the maintenance window 11 than the form shown in FIG. 5B, the link mechanism 20A provided with the spring 40 uses the opening / closing cover 12 as the maintenance window 11. A force is applied in the direction (closing direction Q). On the other hand, when the opening / closing cover 12 is located on the opening direction P side with respect to the form shown in FIG. 5 (B), the link mechanism 20A provided with the spring 40 keeps the opening / closing cover 12 away from the maintenance window 11 ( A force is applied to the opening direction P). In the form shown in FIG. 5B, the first link 21 extends diagonally rearward from the first fixed support portion 25 and is inclined with respect to a line (not shown) forming the left-right direction of the hydraulic excavator 1. .. Similarly, the second link 22 extends diagonally rearward from the second fixed support portion 26 and has a shape inclined with respect to a line forming the left-right direction of the hydraulic excavator 1. At this time, the inclination of the first link 21 becomes larger than the inclination of the second link 22. Further, the length of the spring 40 is the longest in the form shown in FIG. 4 (B).

FIG. 5C shows a form in which the opening / closing cover 12 is further moved toward the opening direction P side as compared with FIG. 5B, and the opening / closing cover 12 is in the process of being moved. In this form, the first link 21 and the second link 22 extend from the first fixed support portion 25 and the second fixed support portion 26 toward the rear of the hydraulic excavator 1. Therefore, the spring support 23 formed on the second link 22 projects toward the side of the hydraulic excavator 1. Further, the link mechanism 20A provided with the spring 40 applies a force to the opening / closing cover 12 in the opening direction P.

FIG. 5D shows a form in which the opening / closing cover 12 is completely opened. Although not particularly shown in FIG. 5, the maintenance window opening / closing mechanism 20 is provided with a stopper for stopping the operation of the link mechanism 20A, and the opening / closing cover 12 is located at a position closer to that shown in FIG. 5 (D). It prevents the vehicle from moving to the P side in the opening direction. In this embodiment, the first link 21 and the second link 22 extend from the first fixed support portion 25 and the second fixed support portion 26 to the rear side of the hydraulic excavator 1 in a direction slightly inclined to the right side of the drawing. There is. Further, the second moving support portion 28 is located at a position rearward from the counterweight 10 with respect to the first moving support portion 27. Therefore, the opening / closing cover 12 is located on the side of the maintenance window 11. Further, the opening / closing cover 12 is tilted with respect to the left-right direction, and the left end portion 12a in the left-right direction in the figure is located at a position farther from the counterweight 10 than the right end portion 12b. As a result, a wide space is formed between the opening / closing cover 12 and the maintenance window 11.

As shown in FIGS. 5 (A) to 5 (D), the opening / closing cover 12 changes from the closed state of the maintenance window 11 of FIG. 5 (A) to the completely open state of FIG. 5 (D). Until it moves, it moves within a range separated from the outer surface of the counterweight 10 by a certain short distance. Therefore, in the maintenance window opening / closing mechanism 20 of this embodiment, even if a large space cannot be secured behind the counterweight 10, the opening / closing cover 12 is moved to close or open the maintenance window 11. Can be done.

FIG. 6 shows a view in which the opening / closing cover 12 closes the maintenance window 11 and a form in which the opening / closing cover 12 is completely open, as viewed from behind the counterweight 10. FIG. 6A shows a form in which the opening / closing cover 12 closes the maintenance window 11, and corresponds to FIG. 5A. Further, FIG. 6B shows a form in which the opening / closing cover 12 is completely opened, which corresponds to FIG. 5D.

In the form shown in FIG. 6A, the maintenance window 11 formed at the central portion and the lower portion of the counterweight 10 in the left-right direction is closed by the opening / closing cover 12. This form is in a normal working state such as when excavation work is performed by using the hydraulic excavator 1. On the other hand, in the form shown in FIG. 6B, the opening / closing cover 12 is moved toward the opening direction P side of the maintenance window 11, and the end portion 12a of the opening / closing cover 12 on the closing direction Q side is the end on the opening direction P side. It is located at a position farther behind the hydraulic excavator 1 from the counterweight 10 than the portion 12b. Therefore, a large space is formed behind the maintenance window 11. As a result of forming a wide space behind the maintenance window 11, the worker H can perform the maintenance work without being disturbed by the opening / closing cover 12.

1 Hydraulic excavator 2 Machine body 3 Traveling body 4 Traveling frame 5 Crawler 6 Motor 7 Swinging body 8 Operator cabin 9 Engine room 10 Counterweight 11 Maintenance window 12 Opening / closing cover 12a, 12b End 15 Work unit 16 Boom 17 Arm 18 Bucket 20 Maintenance window opening / closing mechanism 20A Link mechanism 21 First link 21a One end of the first link 21b The other end of the first link 22 Second link 22a One end of the second link 22b The other end of the second link 23 Spring support 25 First Fixed support part 26 2nd fixed support part 27 1st moving support part 28 2nd moving support part 31 Mounting bracket 32 Bracket 40 Spring 40a One end of spring 40b The other end of spring 50 Support pin 51, 52 Mounting pin H Worker

Claims (2)

A maintenance window opening / closing mechanism formed on a counterweight attached to the rear of a construction machine to open / close the maintenance window that connects the inside of the construction machine with the drive equipment and the outside of the construction machine. And
An opening / closing cover that opens / closes the maintenance window, a link mechanism that connects the opening / closing cover and the counterweight with two rod-shaped links, and moves the opening / closing cover in the horizontal direction with respect to the counterweight, and the link. With a spring provided in the mechanism,
The link mechanism
The link is rotatably supported at one end on the counterweight side in the longitudinal direction of the link, and includes a first fixed support portion and a second fixed support portion arranged side by side in the horizontal direction. With
The link is rotatably supported at the other end of the opening / closing cover side in the longitudinal direction of the link, and the first moving support portion and the second moving support portion arranged side by side in the horizontal direction are supported. Prepare,
The first fixed support portion and the first moving support portion are connected by a first link, and the second fixed support portion and the second moving support portion are connected by a second link.
The distance between the first fixed support portion and the second fixed support portion is set to be smaller than the distance between the first moving support portion and the second moving support portion.
The first fixed support portion and the first moving support portion move from a form in which the opening / closing cover is closed to a form in which the maintenance window is opened rather than the second fixed support portion and the second moving support portion. Arranged on the open direction side, which is the direction, the first link is shorter than the second link.
In the form in which the opening / closing cover closes the maintenance window, the first fixed support portion, the second fixed support portion, the first moving support portion, and the second moving support portion are arranged linearly in the horizontal direction. Being done
In a form in which the opening / closing cover moves to open the maintenance window, when the opening / closing cover is present at a position close to the maintenance window, the link mechanism provided with the spring provides the opening / closing cover with the maintenance. When the opening / closing cover is located on the opening direction side, the link mechanism provided with the spring acts to apply a force in the closing direction toward the opening / closing cover, and the opening / closing cover is used as the maintenance window. The opening / closing cover acts to apply a force in the opening direction to move away from the counter weight, and the opening / closing cover is separated from the outer surface of the counter weight by a certain short distance until the maintenance window is moved from the closed form to the open form. Move within the range
A maintenance window opening / closing mechanism that is characterized by this. A pair of upper and lower link mechanisms are provided, and the first fixed support portion and the second fixed support portion arranged on the upper side are provided on the upper part of the maintenance window, and the first moving support portion and the second fixed support portion are provided. The moving support portion is attached to the upper side of the opening / closing cover, and the first fixed support portion and the second fixed support portion arranged on the lower side are provided at the lower part of the maintenance window, and the first moving support portion and The maintenance window opening / closing mechanism according to claim 1 , wherein the second moving support portion is attached to the lower side of the opening / closing cover.

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