JP2012035764A - Door opening and closing mechanism of working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and smoothly carry out an opening/closing operation of a door as well as not to have guide rails project outside a cab.SOLUTION: A link type door opening/closing mechanism 17 of a wheel loader 1 is provided with guide rails of guide grooves 15, 16 over and under a doorway 12 provided in the cab 10. Guide roller sections 27, 35 including rollers 26, 34 are provided above and below the front end of the door 13. The roller is moved along the guide rails. A link 37 is provided with a connection shaft 37a attached to an outer wall 11 which is adjacent to the doorway 12 of the cab as well having a movable shaft 37b on the other end attached to the rear end of the door 13. The link 37 is made turnable so that the turnable shaft 37b may be positioned on the opposite side with a connection shaft 37a as the center in the closed position and the opened position of the door 13. When the door 13 is opened, the door is moved to the open position by having the roller slid along the guide rails in the front end of the door and having the rear section of the door 13 turned by the turnable shaft 37b with the connection shaft 37a of the link 37 as the center in the rear end of the door.

Description

  The present invention relates to a door opening / closing mechanism provided in a cab or the like of various working machines including a construction machine.

  Generally, a door of a cab provided in a construction machine, such as a hydraulic excavator or a wheel loader, is connected to an outer wall of the cab by a hinge and pivots around the hinge to open and close. In addition, some small hydraulic excavators are characterized in that the turning radius of the upper swing body is small. In such small hydraulic excavators, the door slides on the rail provided on the outer wall of the cab and opens and closes the entrance / exit. Some sliding doors are activated.

In the wheel loader 1 shown in FIG. 9 as an example of such a construction machine, tires are provided in the vehicle body, and the cab 3 provided in the wheel loader body 2 is relatively high. The cab 3 is provided with a door 4 through which an operator enters and exits. In order for the operator to enter and exit the cab 3, the ladder or the step 7 provided between the front and rear wheels 5 and 6 is moved up and down to drive The door 4 of the chamber 3 will be opened and closed. Further, a space 8 on the passage having the same height as the floor of the driver's cab 3 protrudes to the outside of the driver's cab 3 so that work can be easily performed when the vehicle is maintained.
Since the door 4 provided in the cab 3 of the wheel loader 1 is formed wider than the space 8 on the passage provided outside the entrance of the cab 3, the door 4 can be smoothly moved while standing in the space 8. Can't be opened. Therefore, in the wheel loader 1, it is necessary to open and close the door 4 while standing at a position lower than the cab 3 on the step 7, and the door knob and the lock release lever are also provided at the positions where the operation can be easily performed on the step 7. .

  Further, for example, in the door structure of the cabin for a work vehicle described in Patent Document 1, a sliding door is employed. In this sliding door, a guide rail that supports the door so as to be slidable is provided on the outer wall of the cab on the rear end side of the doorway. And since the width | variety of a slide door is larger than the width | variety of the outer wall of the entrance / exit rear end side of a driver's cab, the guide rail is extended so that it may jump out back and outside rather than an outer wall.

JP 2007-62576 A

However, in order to open and close the door 4 on the ladder or step 7, the wheel loader 1 described above opens and closes the door 4 with one hand while holding the handrail or the wheel loader body 2 with one hand. In addition, the operation of avoiding the door 4 rotating around the hinge is necessary, and the work on the ladder and the step 7 is complicated.
Further, in the door structure described in Patent Document 1, the rear end of the slide door is slid along the guide rail that protrudes outward from the rear wall of the cab outer wall. Must be supported by guide rails. Therefore, the load of the slide door is applied to the area of the guide rail protruding from the outer wall. In addition, the configuration in which the rear end of the guide rail protrudes from the outer wall of the cab is unsatisfactory and has a problem that it is difficult to perform maintenance work.

  In view of such circumstances, an object of the present invention is to provide a door opening / closing mechanism for a work machine that can easily and smoothly open and close the door and prevent the guide rail from protruding outside the cab. .

A door opening / closing mechanism for a work machine according to the present invention includes a support structure for opening and closing a door by sliding along a guide rail located at least one of an upper side and a lower side of an entrance / exit provided in a cab. In the opening and closing mechanism,
A connecting member is attached to the outer wall adjacent to the doorway of the cab and one end of the connecting shaft is attached to the door, and the other end of the connecting shaft is attached to the door. The connecting member is movable around the connecting shaft between the closed position and the open position of the door. The shaft is rotatable so that the shaft is located on the opposite side.
According to the door opening and closing mechanism of the work machine according to the present invention, when the door is opened and closed, the connecting member that connects the door and the outer wall of the cab is rotated around the connecting shaft while sliding the door along the guide rail. The door can be moved from the doorway to the open position by sliding the doorway, and the doorway is closed by sliding the door in the open position along the guide rail while rotating the connecting member around the connecting shaft. Can do. Therefore, it is possible to easily rotate the connecting member in the region of the outer wall away from the operator's position while sliding the door along the guide rail in the region near the doorway where the worker operates the door. The door can be opened and closed smoothly, and the guide rail does not have to protrude from the outer wall of the cab. In addition, the protruding length in the radial direction when the connecting member is rotated can be set to half or less of the door width, and the occupied space can be reduced.
In addition, it is preferable that the door is slid on the front end side and the rear end side is rotated by the connecting member.

Moreover, it is preferable that the recessed part which can accommodate a connection member is formed in the outer wall of a driver's cab.
By allowing the connecting member to be accommodated in the recessed portion of the outer wall while the door is closed, unnecessary protrusions can be suppressed in the area of the cab door and the outer wall, and the movable range of the connecting member is expanded and the door is opened. When the sliding operation is performed, a load in the rotation direction around the coupling shaft can be applied to the connecting member.

Further, the connecting shaft of the connecting member is preferably attached to the outer wall at an intermediate position between the movable shaft at the door closed position and the movable shaft at the open position.
When the connecting member is rotated about the connecting shaft by opening and closing the door, the connecting member only needs to have a length that is approximately half or less of the door opening and closing movement range, so that the amount of protrusion of the door during rotation is small. Therefore, the operator can open and close the door easily and smoothly.

The connecting member is a link member.
In this case, the door to be opened / closed can be opened / closed by moving by a length approximately double the rotational radius of the length of the link member.

The connecting member is a slide rod having a cylinder part and a rod part that can be advanced and retracted from the cylinder part, and the rod part protrudes and extends from the cylinder part in at least one of the closed position and the open position of the door. It is characterized by.
In this case, since the slide rod can be controlled so that the rod portion can be moved back and forth from the cylinder portion, the door is opened and closed by moving about 3 to 4 times the length of the cylinder portion due to the expansion and contraction of the slide rod caused by the opening and closing operation of the door. In addition to being able to operate, the door only opens and closes in the radial direction with a radius of rotation due to the length of the contracted cylinder part, so that the space occupied when opening and closing the door is small and can be opened and closed easily.
Since the distance from the connecting shaft to the movable shaft in the closed position of the door is set to approximately twice the distance from the movable shaft in the open position to the slide rod, when the door is operated from the closed position to the open position, The slide rod can be shrunk to about ½, and the occupied space is reduced.

  According to the door opening and closing mechanism of the working machine according to the present invention, when the door is opened and closed, the connecting member that connects the door and the outer wall of the cab is rotated around the connecting shaft while sliding the door along the guide rail. Thus, the door can be opened and closed. Therefore, since the door slides along the guide rail in the area of the doorway where the operator opens and closes the door, the door can be opened and closed easily and smoothly. Since the door is rotated with a radius, the protruding length in the radial direction can be reduced to ½ or less of the width of the door, and the occupied space when the door is opened and closed can be easily reduced. Therefore, unlike the conventional door opening / closing mechanism, it is not necessary to extend the guide rail to a position protruding from the outer wall of the cab, and it is easy to perform maintenance work.

  In addition, since the present invention has a recess that can accommodate the connection member on the outer wall of the cab, it is possible to suppress unnecessary protrusions in the region of the door and the outer wall of the cab and widen the movable range of the connection member, When the sliding operation is performed to open the door, it is possible to apply a load in the rotational direction around the connecting shaft to the connecting member.

  In the present invention, since the connecting shaft of the connecting member is attached to the outer wall at an intermediate position between the movable shaft in the closed position of the door and the movable shaft in the open position, the connecting member is connected to the connecting shaft by opening and closing the door. When rotating around, the connecting member only needs to have a length that is approximately half or less of the opening / closing movement range of the door, so that the projection amount of the door during rotation is small. Therefore, the exclusive space for opening and closing the door can be small, and the operator can open and close the door easily and smoothly.

Moreover, since the connecting member is a link member, the door can be opened and closed by moving the door to be opened / closed by a length approximately twice as long as the rotational radius of the link member.
The connecting member is a slide rod having a cylinder part and a rod part that can be advanced and retracted from the cylinder part, and the rod part protrudes and extends from the cylinder part at least one of a closed position and an open position of the door. Therefore, the slide rod can be controlled so that the rod portion can be moved back and forth from the cylinder portion, and the door can be opened and closed by moving about 3 to 4 times the length of the cylinder portion due to the expansion and contraction of the slide rod caused by the opening and closing operation of the door. At the same time, the opening and closing door only protrudes in the radial direction with the radius of rotation due to the length of the cylinder portion contracted, and therefore, the space occupied when the door is opened and closed can be opened and closed smoothly.

  In addition, the slide rod has a distance from the connecting shaft to the movable shaft at the door closed position that is approximately twice the distance from the movable shaft at the open position. The slide lock at the time is contracted to occupy a small space, and the guide rail does not protrude to the outside of the cab when opened as in the prior art.

It is a principal part block diagram which shows the cab and door opening / closing mechanism of the construction machine by 1st embodiment of this invention. (A), (b) is a top view which shows the door opening / closing operation | movement by the door opening / closing mechanism shown in FIG. It is a principal part disassembled perspective view which shows the guide roller part and upper guide rail which were provided in the door upper end. It is an AA line principal part longitudinal cross-sectional view which shows the relationship between the guide roller part shown in FIG. 3, and an upper guide rail. It is a principal part disassembled perspective view which shows the guide roller part and lower guide rail which were provided in the door lower end. It is a BB line principal part longitudinal cross-sectional view which shows the relationship between the guide roller part shown in FIG. 5, and a lower guide rail. It is a principal part block diagram which shows the cab and door opening / closing mechanism of the construction machine by 2nd embodiment of this invention. It is a top view which shows the opening / closing operation | movement of the door by the door opening / closing mechanism shown in FIG. It is a side view of a general wheel loader.

Hereinafter, a door opening and closing mechanism in a construction machine according to an embodiment of the present invention will be described. As a construction machine, for example, a wheel loader shown in FIG.
1 to 6 show a cab in the wheel loader 1 according to the first embodiment of the present invention.
As shown in FIG. 1, the wheel loader 1 that is an example of the construction machine according to the present embodiment is provided with a cab 10 at an intermediate upper portion between the front and rear wheels 5 and 6. On one side of the cab 10, a door 13 and an outer wall 11 for opening and closing an entrance 12 for entering and exiting the driver's seat are provided. In addition, although the handle 14 is provided in the lower part of the front end side of the door 13, you may provide the handle 14 in the height direction intermediate part.
In the present specification, in the cab 10 shown in FIG. 1, the rear end side (right side in the figure) in the direction of closing the door 13 is referred to as the rear end or rear part, and the front end side (left side in the figure) in the closing direction. Is called the front end or front part.

In the cab 10 shown in FIG. 1, link type or rail type guide mechanisms 15, 16 that support the door 13 so as to be horizontally movable are provided at the upper and lower end portions of the entrance / exit 12. The door opening / closing mechanism 17 is provided.
Next, the guide mechanisms 15 and 16 will be described with reference to FIGS.
In the upper guide mechanism 15 shown in FIGS. 3 and 4, a guide groove 19 is formed on the back surface side of the outer wall 11 at the upper part of the entrance / exit 12 of the cab 10 so as to extend in the opening / closing direction of the door 13. The guide groove 19 extends from the front end to the rear end of the entrance / exit 12 and further extends in the rear end direction by partially cutting the outer wall 11.
In the cross-sectional view of the guide groove 19 shown in FIG. 4, the guide groove 19 has a concave groove shape with an opening formed on the side surface, and a guide wall 20 extending on the extension of the outer wall 11 from the upper end of the guide groove 19 downward. A lower opening 21 is provided in which the opening of the guide groove 19 is narrowed by the guide wall 20. The lower end of the opening 21 is partitioned by the outer wall 11 in the region of the outer wall 11 of the cab 10, but the lower end of the opening 21 is not partitioned in the region of the doorway 12.
A guide rail 22 is provided on the back surface of the guide wall 20 on the guide groove 19 side.

  At the upper front end of the door 13, an arm part 25 is formed on the back surface facing the guide groove 19, and for example, an upward roller 26 is rotatably attached to the tip of the arm part 25. The arm portion 25 and the roller 26 constitute a guide roller portion 27. The roller 26 is inserted into the guide groove 19 through the opening 21 and is moved horizontally while bringing the peripheral surface of the roller 26 into contact with the guide rail 22 of the guide wall 20 when the door 13 is opened and closed in the horizontal direction.

Further, the lower guide mechanism 16 shown in FIGS. 5 and 6 has substantially the same configuration as the upper guide mechanism 15. That is, in FIGS. 5 and 6, a guide groove 28 is formed in the lower part of the entrance / exit 12 of the cab 10 on the back side of the outer wall 11 so as to extend in the opening / closing direction of the door 13. The guide groove 28 extends from the front end to the rear end of the entrance / exit 12 and further extends in the rear end direction by partially cutting the outer wall 11.
In the cross-sectional view of the guide groove 28 shown in FIG. 6, the guide groove 28 has a concave groove shape with an opening formed on the side surface, and a guide wall 29 extending on the extension of the outer wall 11 downward from the upper end of the guide groove 28. A lower opening 30 is provided in which the opening of the guide groove 28 is narrowed by the guide wall 29. The opening 30 is provided over the same length as the guide groove 28 along the extending direction of the guide groove 28.
A guide rail 31 is provided on the back surface of the guide wall 29 on the guide groove 28 side.
In addition, the guide rails 22 and 31 provided in the guide grooves 19 and 28 shall have the front-end | tip part curved so that it might bite into the driver's cab 10 in the area | region of the front end side.

  As shown in FIG. 5, an arm part 33 is formed on the back surface facing the guide groove 28 at the lower front end of the door 13, and an upward roller 34 is rotatably attached to the tip of the arm part 33. ing. The arm portion 33 and the roller 34 constitute a guide roller portion 35. The roller 34 is inserted into the guide groove 28 through the opening 30 and horizontally moves while the peripheral surface of the roller 34 is in contact with the guide rail 31 of the guide wall 29 when the door 13 is opened and closed in the horizontal direction.

Next, the link type door opening / closing mechanism 17 will be described with reference to FIGS.
In the outer wall 11 on which the door 13 is slid and overlapped when opened, one longitudinal end of a substantially rod-shaped link 37 is rotatably fixed to the outer wall 11 as a connecting shaft 37a at the center in the height direction. The other end portion of the link 37 is rotatably connected to a central portion in the height direction at the rear portion of the rear surface facing the outer wall 11 side of the door 13 as a movable shaft 37b.
The rotation structure of the connecting shaft 37a and the movable shaft 37b in the link 37 is arbitrary. It is set as the double axis | shaft arrange | positioned possible. A connecting rod 40 of a link 37 is connected to each cylindrical shaft 39, 39.

2 (a) and 2 (b), the position of the movable shaft 37b of the link 37 in a state where the door 12 is closed by the door 13 and the movable shaft in a state where the door 13 is opened and overlapped with the outer wall 11. A connecting shaft 37a is fixed to the outer wall 11 at an intermediate position of a straight line connecting the position 37b. A line connecting the positions of the movable shafts 37b when the door 13 is opened and closed is approximately twice as long as the link 37, and the link 37 can be reciprocally rotated about 180 ° around the connecting shaft 37a.
Further, the movable shaft 37b attached to the back side of the door 13 in the closed position of the door 13, the connecting rod 40, the connecting shaft 37a supported by the outer wall 11, and the connecting shaft 37a and the connecting rod 40 in the opened position of the door 13 are also shown. A recess 42 for accommodating each part is formed in the outer wall 11. Thereby, the movable range of the link 37 can be expanded.

The link type door opening / closing mechanism 17 of the wheel loader 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.
When the operator opens the door 13 of the cab 10 in the closed state in order to operate the wheel loader 1, the operator goes up step 7 and stands in the space 8 in front of the door 13 of the doorway 12 of the cab 10. Then, the handle 14 is grasped and the door 13 is slid rightward in FIG.
Then, as shown in FIG. 2, the guide rollers 27, 34 in the guide roller portions 27, 35 provided at the front upper and lower ends of the door 13 from the closed position of the doorway 12 are guides provided at the upper and lower portions of the doorway 12. It slides along the guide rails 22 and 31 in the grooves 19 and 28 to perform the opening movement.

When the door 13 is pushed, the rear end of the door 13 is connected to the movable shaft 37b of the link 37 as shown in FIG. The link 37 rises around the connecting shaft 37a. Then, the front end of the door 13 is moved substantially linearly along the guide rails 22 and 31 by the rollers 26 and 34 of the guide roller portions 27 and 35 provided above and below, and the rear end of the door 13 is linked around the connecting shaft 37a. Rotating motion with the length of 37 as a radius.
Then, the rear end of the door 13 is rotated approximately 180 degrees around the connecting shaft 37a by the link 37, and the movable shaft 37b is rotated to a position opposite to the entrance / exit 12 to stop at the recess 42 (FIG. 2B). reference). In this state, the opened door 13 is superimposed on the link 37.

Therefore, even if the operator stands on the spacer 8 in front of the doorway 12 and performs the opening operation of the door 13, the door 13 slides on the front end side of the door 13 where the operator stands. The door 13 can be opened easily and smoothly without touching or colliding with the door 13.
Moreover, since the length of the link 37 is approximately ½ of the width of the door 13, when the rear end of the door 13 is rotated by the link 37, the rotation radius of the link 37 around the connecting shaft 37 a is the door 13. It is only about half the length of the width.

Next, when the door 13 is closed from the open state, the door 13 is pushed to the front end side by pushing the handle 14 of the door 13 in the open state, contrary to the above-described opening operation. , 34 slides substantially linearly along the guide rails 22, 31, and the rear end of the door 13 rotates about 180 degrees around the connecting shaft 37 a of the link 17.
Thereby, the door 13 returns to the position where the doorway 12 is closed. At this time, since the rollers 22 and 34 slide along the guide rails 22 and 31 on the front end side of the door 13, even if an operator such as an operator stands on the stage 8, the door 13 interferes with the door 13 that opens and closes. It is not.

As described above, according to the link type opening / closing mechanism 17 according to the present embodiment, the door 13 can be moved between the open position and the closed position by pushing the door 13 and rotating the link 37 by approximately 180 degrees.
Further, when the operator performs the opening / closing operation of the door 13, the front end side of the door 13 slides along the guide rails 22 and 31, so that there is no possibility of interference with the operator standing in the space 8 of the doorway 12. Can be opened and closed.
Further, when the door 13 is opened and closed, the rear end portion of the door 13 protrudes outward from the outer wall 11 by the maximum length of the link 37, that is, approximately ½ of the width of the door 13, and rotates. Only. Moreover, when the door 13 is opened / closed, the door 13 is opened about half when the door 13 protrudes most from the outer wall 11, and the opening / closing operation is smooth even if the operator stands in the space 8 in front of the entrance / exit 12. . Therefore, it is not necessary to perform the opening / closing operation of the door 13 in step 7, and the opening / closing operation of the door 13 can be performed easily and smoothly.
Further, since the guide rail does not protrude from the outer wall 11 to the rear end side, it looks good and does not disturb the maintenance work.

In addition, this invention is not limited to the above-mentioned embodiment, A various change is possible unless the summary of this invention is changed.
Next, a door opening / closing mechanism according to a second embodiment of the present invention will be described with reference to FIGS.
The second embodiment is different in that a slide rod type door opening / closing mechanism 45 is employed instead of the link type door opening / closing mechanism 17 according to the first embodiment. Accordingly, in the second embodiment, only differences from the first embodiment will be described, and the remaining components will be denoted by the same reference numerals as those in the first embodiment, and description thereof will be omitted.

In the slide rod type door opening / closing mechanism 45 according to the second embodiment, a slide rod 46 is used instead of the link 37 connecting the outer wall 11 and the rear end of the door 13 in the first embodiment.
7 and 8, the slide rod 46 includes a bottomed cylindrical cylinder 47 and a rod 48 that can be moved forward and backward in the cylinder 47 and has torsional rigidity. The rod 48 may be biased in a direction to be accommodated in the cylinder 47 by an elastic body such as a coil spring (not shown).
A connecting shaft 47a having the same structure as the connecting shaft 37a according to the first embodiment is fixed to the outer wall 11 of the cab 10 at the bottom of the cylinder 47, and a movable shaft similar to the movable shaft 37b is attached to the tip of the rod 48. 48 a is fixed to the substantially rear end of the door 13. Therefore, the slide rod 46 is set to be shorter than the width of the outer wall 11 behind the doorway 12 in the extended state in which the rod 48 protrudes from the cylinder 47.

As shown in FIG. 8, the connecting shaft 47 a is fixed to the outer wall 11 at an intermediate position of a straight line connecting the movable shaft 48 a of the slide rod 46 in the closed state of the door 13 and the movable shaft 48 a in the opened position of the door 13. ing. When the distance between the movable shaft 48a and the connecting shaft 47a when the door 13 is closed is La, and the distance between the movable shaft 48a and the connecting shaft 47a when the door 13 is opened is Lb, La: Lb = approximately 2: 1. Is set to
That is, when the door 13 is closed, the rod 48 protrudes from the cylinder 47 in which the connecting shaft 47a is fixed to the outer wall 11, and the rear end of the door 13 is connected to the movable shaft 48a at the front end. Further, when the door 13 is opened, the movable shaft 48a at the tip of the rod 48 accommodated in the cylinder 47 of the slide rod 46 is positioned at a position rotated about 180 degrees around the connecting shaft 47a from when the door 13 is closed. The rear end of the door 13 is connected.
Therefore, the slide rod 46 has the extended length in which the rod 48 protrudes from the cylinder 47 in the closed position of the door 13, and the rod 48 is in the cylinder 47 in the open position of the door 13 and the most protruded radial direction during rotation. It is the most contracted length accommodated inside.

  Further, a movable shaft 48a attached to the back side of the door 13 in the closed position of the door 13, a rod 48 and a cylinder 47 of the slide rod 46, a connecting shaft 47a supported by the outer wall 11, and a connecting shaft in the open position of the door 13. A recess 50 is formed in the outer wall 11 for accommodating each part of 47a and the cylinder 47. Thereby, the movable range of the slide rod 46 can be expanded.

Since the slide rod type door opening / closing mechanism 45 of the wheel loader 1 according to the present embodiment has the above-described configuration, when the operator opens the door 13 of the cab 10 in the closed state in FIG. Then, the handle 14 is gripped and the door 13 is slid rightward.
Then, the rollers 26 and 34 in the guide roller portions 27 and 35 of the guide mechanisms 15 and 16 provided on the front upper and lower ends of the door 13 from the closed position are guided in the guide grooves 19 and 28 provided on the upper and lower portions. It slides along the rails 22 and 31 to perform the opening movement.

When the door 13 is moved from the front end (left side) to the rear end (right side) side, as shown in FIG. 8, the slide rod 46 disposed in the recess 50 inclined with respect to the outer wall 11 rises. Then, the rod 48 connected to the rear end of the door 13 by the movable shaft 48a protrudes from the cylinder 47, and is pushed into the cylinder 47 by the urging force of the elastic member to shorten the entire length while focusing on the connection shaft 47a. The cylinder 47 rotates.
The position where the door 13 protrudes to the outermost side is the shortest length position where the rod 48 of the slide rod 46 is accommodated in the cylinder 47 in the vicinity of the connecting shaft 47a.
Next, the movable shaft 48a at the rear end of the door 13 is rotated by about 180 degrees around the connecting shaft 47a by the slide rod 46, reaches the recess 50 on the opposite side to the entrance 12 and stops. At this time, the slide rod 46 is held at the shortest length in which the rod 48 is accommodated in the cylinder 47. Therefore, the door 13 rotates 180 degrees while the front end side moves substantially linearly and the slide rod 46 on the rear end side shortens the length, and the door 13 overlaps with the slide rod 46 and stops (see FIG. 8).

Next, when the door 13 is closed from the open state, the door 13 is pushed to the front end side by pushing the handle 14 of the door 13 in the open state, contrary to the above-described opening operation. , 34 slides linearly along the guide rails 22, 31, and the rear end of the door 13 is located at the position where the rear end of the door 13 protrudes most by the rotation operation about the connecting shaft 37 a of the slide rod 46. From the point of time, the rod 48 gradually rotates while protruding from the cylinder 47.
Thereby, the door 13 returns to the position where the doorway 12 is closed. At that time, since the rollers 22 and 34 slide along the guide rails 22 and 31 on the front end side of the door 13, there is a possibility that an operator such as an operator may interfere when the door 13 is opened or closed even when standing on the stage 8. Absent.

As described above, according to the slide rod type opening / closing mechanism according to the second embodiment, the door 13 slides substantially in the front-rear direction in the region where the door 13 starts to open and closes. In the region in the vicinity of the connecting shaft 47a that protrudes outward in the radial direction, the rod 48 rotates by the length of the shortest cylinder 47 accommodated in the cylinder 47, so the amount of protrusion of the door 13 is set to the link of the first embodiment. The opening / closing mechanism 17 can be made smaller.
Therefore, when the door 13 is opened, even if an operator stands in the space 8 in front of the entrance 12, the front end of the door 13 slides and the occupied space is small without interfering with the operator. And it can be opened and closed smoothly.

As a modified example of the slide rod type door opening / closing mechanism 45 according to the second embodiment, the rod 48 of the slide rod 46 may be in a position where it protrudes from the cylinder 47 when the door 13 is opened. In this case, the ratio of the length of the slide rod 46 at the open and closed positions of the door 13 is La: Lb = 2: 2. Moreover, when the slide rod 46 is rotated 180 degrees when the door 13 is opened and closed, the length of the slide rod 46 is the length of the cylinder 47 in which the rod 48 is contracted into the cylinder 47 at the position that protrudes most in the radial direction.
The slide rod 46 is housed in the cylinder 47 when the door 13 is closed, and is in a state in which the rod 48 protrudes from the cylinder 47 in the opened state, that is, La: Lb = 1: 2. It may be configured.

The guide mechanisms 15 and 16 and the guide roller portions 27 and 35 do not have to be provided above and below the entrance / exit 12, and may be provided at least in one of them.
Needless to say, the present invention is not limited to the wheel loader 1 and can be applied to a working machine including various construction machines such as a hydraulic excavator.
The link type door opening / closing mechanism 17 and the slide rod type door opening / closing mechanism 45 constitute a door opening / closing mechanism. The link 37 in the link type door opening / closing mechanism 17 and the slide rod 46 including the cylinder 47 and the rod 48 in the slide rod type door opening / closing mechanism 45 constitute a connecting member.
Note that the guide roller portions 27 and 35 may be connected by interposing other members so as to be relatively rotatable with bolts or the like without directly connecting the arm portions 25 and 33 to the door 13. In this case, the relative angle between the arm portions 25 and 33 and the other members can be adjusted according to the curvature of the guide rails 22 and 31 and the opening and closing movement position of the door 13, so that the door 13 can be opened and closed more smoothly.

DESCRIPTION OF SYMBOLS 1 Wheel loader 10 Driver's cab 11 Outer wall 12 Entrance / exit 13 Door 15, 16 Guide mechanism 19, 28 Guide groove 17 Link-type door opening / closing mechanism 22, 31 Guide rail 27, 35 Guide roller part 26, 34 Roller 37 Link 37a, 47a Connecting shaft 37b, 48a Movable shaft 40 Link rod 42, 50 Recess 45 Slide rod type door opening / closing mechanism 46 Slide rod 47 Cylinder 48 Rod

Claims (6)

In a door opening / closing mechanism of a work machine provided with a support structure that slides along a guide rail located at least one of an upper side and a lower side of an entrance / exit provided in a cab, and opens / closes the door,
A connecting member is attached to the outer wall adjacent to the doorway of the cab and one end of the connecting shaft is attached to the door, and the other end of the connecting shaft is attached to the door. The connecting member is movable around the connecting shaft between the closed position and the open position of the door. A door opening and closing mechanism characterized in that it is rotatable so that the shaft is located on the opposite side.   The door opening / closing mechanism according to claim 1, wherein a recess capable of accommodating a connection member is formed on an outer wall of the cab.   The door opening / closing mechanism according to claim 1 or 2, wherein the connecting shaft of the connecting member is attached to the outer wall at an intermediate position between the movable shaft in the door closed position and the movable shaft in the open position.   The door opening / closing mechanism according to claim 1 or 2, wherein the connecting member is a link member.   The connecting member is a slide rod having a cylinder part and a rod part that can be advanced and retracted from the cylinder part, and the rod part protrudes and extends from the cylinder part in at least one of a closed position and an open position of the door. The door opening / closing mechanism according to claim 1 or 2.   The door opening / closing mechanism according to claim 5, wherein the slide rod is set such that a distance from the connecting shaft to the movable shaft at the closed position of the door is twice as long as a distance from the movable shaft at the opened position.

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