JP2003237365A - Front window lock device for cab - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the operability of release levers for a closing lock device and an opening lock device and enable secure locking, in a cab equipped with an opening and closing front window, a handle to be held to open and close the front window, and the respective closing and opening lock devices for performing locking respectively at the respective closing and opening positions. <P>SOLUTION: The releasing levers 8, 9 for the closing and opening lock devices are disposed at such a section that the handle 5 can be operated by the fingers of a hand holding the handle 5. A lock pin 29 capable of being fitted into a fitting hole on the cab side is provided to form a double lock structure consisting of the closing and opening lock devices and lock pins. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a front window locking device for locking a front window provided in a cab of a construction machine or the like.

[0002]

2. Description of the Related Art Generally, a front window provided in a cab of a construction machine or the like has a closed position for closing a window opening on the front of the cab and an open position for storing the window opening in the cab ceiling. There are some that can be opened and closed freely,
In this case, the windshield must be locked in the closed position to prevent crime when the construction machine is not in use, and the windshield should not be accidentally dropped when the windshield is open. Must be locked in the open position. Therefore, conventionally, a locking device for locking the front window at each of the closed and open positions is provided. As such a locking device, for example, as shown in Japanese Utility Model Laid-Open No. 4-134710, the front window side is provided. While a lock pin that can be retracted and retracted is provided, a fitting hole into which the lock pin can be fitted is provided on the cab side when the front window is located at each of the closed and open positions, and the lock pin is fitted into the fitting hole to allow the front Some have windows that can be locked in various positions.

[0003]

However, in the case of the above-mentioned publication, it is difficult to align the lock pin with the fitting hole, and there is a problem that the lock operation is time-consuming. Therefore, a locking device has been proposed that automatically locks when the front window reaches each of the closed and open positions. However, in this case,
For closing, which locks the front window at each position of closed and open,
It is necessary to configure the unlocking operation of each locking device for opening to be easily performed. Also, since the automatic locking will not be performed in the state where the front window has not reached the closed and open positions, the operator can open and close the front window at a position before the operator is automatically locked. If you stop the machine, the operator may think that it is locked even though it is not automatically locked, but in this case, the open front window is inadvertently vibrated. There is a fear of falling, and consideration must be taken to avoid such a problem, and these have a problem to be solved by the present invention.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances in order to solve these problems, and has a closed position for closing a window opening in the front of a cab. A front window housed in the cab ceiling and openable and closable in an open position for opening the window opening, and a closing lock and an opening lock for locking the front window at each of the closed and open positions. In a cab provided with a device and a handle provided on the front window for gripping when opening and closing the front window, each of the locking devices for closing and opening is located at each position of closing and opening the front window. The lock body provided on the front window side is automatically locked in each position by engaging the lock body provided on the front window side with the lock receiving body provided on the cab side due to the fact that it is closed and opened. Closed lock to unlock each locking device置用, each release lever for opening the locking device, in which arranged in a portion that can be operated by a finger of the hand holding the handle. By doing so, the operation of the release levers for the closing lock device and the opening lock device can be performed by one-touch operation of the fingers of the hand while holding the handle, which is excellent in operability. At the same time, it is possible to surely eliminate the problem that the front window suddenly slides down immediately after unlocking the opening locking device. In this structure, by attaching the handle to the side surface of the front window, it becomes easier to operate the release lever with a finger holding the handle. Also, the release levers for the closing lock device and the opening lock device are
By making the operating directions for releasing the locks of the closing and opening lock devices the same, the operator is not confused about the operating direction, and it is possible to contribute to further improvement in operability. Further, the release levers for the closing lock device and the opening lock device are in a state in which the release lever for the open lock device is located on the upper side and the release lever for the close lock device is located on the lower side when the front window is in the closed position. By arranging them side by side in parallel with each other, the position of the front window and the position of the release lever to be operated match, and the operator can easily recognize which release lever to operate. There is an advantage that you can. Furthermore, while the front window is provided with a lock pin that can be retracted from the side surface of the front window, the lock pin can be inserted into the cab side when the front window is closed or opened. By providing the hole, the front window is doubly locked by the locking device and the locking pin, so that the opening and the locking at each position can be ensured. Moreover, since the locking operation of the lock pin is performed after the automatic locking, it is possible to check whether or not the automatic locking is securely performed, and it is not necessary to align the locking pin with the fitting hole. Can also be done easily.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a cab of a construction machine such as a hydraulic excavator, and a front opening of the cab 1 has a window opening 1a. Reference numeral 2 is a front window, and the front window 2 is constructed by assembling a transparent plate 2b such as a glass plate to the upper, lower, left and right window frames 2a. A guide roller 3 is attached to the portion, and the guide roller 3 is rotatably guided by left and right inverted L-shaped guide rails 4 laid from the front portion of the cab 1 to the ceiling portion. By doing so, the front window 2 can be opened and closed between a closed position where the window opening 1a is closed and an open position where the window 2 is stored in the ceiling of the cab 1 and opens the window opening 1a. .

On the other hand, reference numeral 5 is a handle attached to the window frame 2a so as to be gripped by an operator when the front window 2 is opened and closed, and in the present embodiment, it is on the right (as viewed from the inside of the cab 1). The right side handle 5A is on the upper side of the side window frame 2a, the left side handle 5B is on the left side (the left side when viewed from the inside of the cab 1, and so on), and the lower side window frame is also on the upper side of the side window frame 2a. A lower handle 5C is attached to the left part of 2a.

Further, the upper window frame 2a of the front window 2 is closed for locking the front window 2 in the closed and open positions.
Opening lock devices 6 and 7, closing lock device release levers 8 and 9 for unlocking the opening and closing lock devices 6 and 7, and open lock device release levers 8 and 9, respectively. An automatic locking device 12 including connecting rods 10 and 11 for closing and opening for connecting the locking devices 6 and 7 and the respective release levers 8 and 9 is attached. It is arranged so as not to hang below the upper window frame 2a so as not to impair the upper field of view of the window 2. Further, the release levers 8 and 9 for the closing lock device and the opening lock device are arranged at a portion which can be operated by the thumb of the right hand holding the right handle 5A.
When the front window 2 is in the closed position, the open lock device release lever 9 is located on the upper side, and the close lock device release lever 8 is located on the lower side so as to be arranged side by side vertically.

On the other hand, 13 and 14 are lock receiving bodies for closing and opening which are mounted on the cab 1 side through mounting brackets 13a and 14a, respectively.
8 has a U-shape as shown in FIG. 8, but the closing lock receiver 13 has a window opening so that the closing lock receiver 13 engages with the closing lock device 6 when the front window 2 is in the closed position. 1a is fixed to the upper part, and the opening lock receiver 14 is a front window 2
Is fixed to the rear portion of the ceiling of the cab 1 so as to engage with the opening locking device 7 when is opened.

Next, the structure of the closing lock device 6 will be described. The closing lock receiver 13 moves in and out of the case body 15 constituting the closing lock device 6 as the front window 2 is opened and closed. A fitting groove 15a that can be freely fitted is formed. 16 is a shaft 16 on the case body 15 side.
A closing lock plate pivotally supported via a, the closing lock plate 16 including the fitting groove 15
a contact piece 16b that abuts the closing lock receiver 13 that is about to be fitted into a, a locking piece 16c that prevents the closing lock receiver 13 that is fitted into the fitting groove 15a from coming off, and a closing stopper 17 that will be described later. A lock receiving portion 16d for locking the claw portion 17b is formed. And this lock plate 16
A locking posture in which the lock piece 16c projects into the fitting groove 15a (shown by a solid line in FIG. 9A) and a standby posture in which the contact piece 16b projects into the fitting groove 15a (a chain line in FIG. 9A) (Shown with), and is constantly urged toward the standby position by a spring 18 described later. Further, the closing stopper 17 is swingably supported on the case body 15 side via a shaft 17a, and the closing stopper 17 is provided when the closing lock plate 16 is in the locking posture. A claw portion 17b that engages with the engagement receiving portion 16d of the closing lock plate 16 is formed and is also connected to the closing lock device release lever 8 via a closing connecting rod 10. The closing stopper 17 has a pawl portion 17b and a pawl portion 17b in a locking posture (shown by a solid line in FIG. 9B) in which the pawl portion 17b engages with the lock receiving portion 16d of the opening lock plate 16 in the locking posture. The standby position in which the upper end of the abutment contacts the lower surface of the opening lock plate 16 (see FIG.
(Shown by a chain line in (B)) and is constantly urged by the spring 18 toward the locking posture side. By swinging beyond the locking position toward the anti-locking position, it can be transformed into a releasing position (shown by a chain double-dashed line in FIG. 9B) that does not interfere with the closing lock plate 16. Furthermore, the spring 18 is interposed between the closing lock plate 16 and the closing stopper 17, and as described above, the closing lock plate 16 is in the standby posture side by the urging force of the spring 18. On the other hand, the closing stopper 17 is always biased toward the locking posture.

When the front window 2 is in the open position, the closing lock plate 16 of the closing lock device 6 is closed.
Both the closing stopper 16 and the closing stopper 16 are held in the standby posture (see FIG. 7). When the front window 2 is closed from this state, the closing lock receiver 13 is fitted from the entrance 15b of the fitting groove 15a of the case body 15 immediately before the front window 2 reaches the closed position. The lock receiving body 13 for closing fitted in the fitting groove 15a
Abut against the abutment piece 16b of the closing lock plate 16 and press the abutting piece 16b, whereby the closing lock plate 16 swings to the lock posture side against the biasing force of the spring 18.
Then, when the front window 2 is located at the closed position, the closing lock receiver 13 reaches the groove bottom portion of the fitting groove 15a, the closing lock plate 16 is in the locking posture, and the locking piece 16c in the locking posture is closed. It is set to lock the relative movement of the closing lock receiver 13 by engaging with the closing lock receiver 13. The closing stopper 17 receives the urging force of the spring 18 as the closing lock plate 16 is transformed into the locking posture, and the claw portion 17b engages with the locking receiving portion 16d of the closing lock plate 16. It is configured to swing and transform into a locking posture to stop, and the closing lock plate 16 can be held in the locking posture by the closing stopper 17 in the locking posture. Thus, in cooperation with the position of the front window 2 in the closed position, the closing lock plate 16 engages with the closing lock receiver 13 to restrict the relative movement of the closing lock receiver 13. While swinging and transforming to the posture, the closing stopper 17 transforms to the locking posture to hold the closing lock plate 16 in the locking posture, whereby the closing window 6 of the front window 2 in the closing position by the closing lock device 6 is held. It is configured to be locked (see FIG. 6). On the other hand, when the front window 2 is opened, the lock of the closing lock device 6 is released. In this case, the closing lock device release lever 8 is moved to the right release position side as described later. When operated, the closing connecting rod 10 moves to the right,
The closing stopper 17 is swung to the release position. As a result, the lock receiving portion 16d of the closing lock plate 16 and the claw portion 17b of the closing stopper 17 are disengaged, and the closing lock plate 16 is allowed to swing toward the standby position. Becomes If the front window 2 is moved to the open side in this state,
While the closing lock receiver 13 moves relatively to the entrance 15b side of the fitting groove 15a and comes out of the fitting groove 15a, the closing lock plate 16 swings into a standby position. And
Lock plate 16 for closing, which is swingably transformed to the standby position
Is held in the standby posture by the urging force of the spring 18.

The opening locking device 7 is different in shape from the closing locking device 6 described above, but has substantially the same structure and operation. A fixed plate 20 having a fitting groove 20a is fixedly provided on the lock plate 21 and an opening lock plate 21 having a contact piece 21b, a lock piece 21c, and a lock receiving portion 21d swings through a shaft 21a. The opening stopper 22 is movably supported by a shaft and further has a claw portion 22b.
The opening stopper 22 is pivotally supported via 2a, and the opening stopper 22 is connected to an opening lock device release lever 9 via an opening connection rod 11. The lock plate 21 for opening is the lock plate 16 for closing described above.
Similarly, while swinging and changing to a lock posture (shown by a solid line in FIG. 10) and a standby posture (shown by a one-dot chain line in FIG. 10), the spring 23 is constantly biased toward the standby posture by the biasing force of the spring 23. Like the closing stopper 17, the opening stopper 22 has a locking posture (shown by a solid line in FIG. 10) and a standby posture (see FIG. 10).
(Shown by the one-dot chain line) and the release posture (shown by the two-dot chain line in FIG. 10), and is constantly biased toward the locking posture by the biasing force of the spring 24.

When the front window 2 is in the closed position, the opening lock plate 21 of the opening lock device 7 is opened.
Both the opening stopper 22 and the opening stopper 22 are held in the standby posture (see FIG. 6). When the front window 2 is opened from this state, the opening lock plate 21 is engaged with the opening lock receiver 14 fitted in the fitting groove 20a in cooperation with the opening of the front window 2 at the open position. The opening lock 22 is changed to the lock posture that restricts the relative movement of the opening lock receiver 14, and the opening stopper 22 is swingably changed to the locking posture to hold the opening lock plate 21 in the lock posture. The front window 2 in the open position is locked by the opening locking device 7 (see FIG. 7). On the other hand, when closing the front window 2,
As will be described later, when the release lever 9 for the opening lock device is operated to the release position side in the right direction, the opening connecting rod 11 moves in the right direction and the opening stopper 22 is transformed into the release position.
As a result, the opening lock plate 21 is allowed to swing toward the standby position. When the front window 2 is moved to the closing side in this state, the opening lock receiver 14 is inserted into the fitting groove 20a.
As it exits, the opening lock plate 21 swings to the standby position.

On the other hand, both the release levers 8 and 9 for the closing lock device and the opening lock device are pivotally supported by the upper window frame 2a of the front window 2 through a support shaft 25, respectively. On the release levers 8 and 9 for the closing lock device and the opening lock device, connecting portions 10a and 11a bent and formed at the right end portions of the connecting and closing connecting rods 10 and 11 are slidably movable. The long holes 8a and 9a to be fitted are opened.
When the release levers 8 and 9 are not operated by the operator, the lever spring 2 is used.
The release levers 8 and 9 for the closing lock device and the opening lock device are in the closing position by the urging force of 6 and are in a state of vertically overlapping with each other.
Since the stoppers 17 and 22 for opening act in substantially the same manner, the release lever 8 for the closing lock device will be described below as an example.

The release lever 8 for the closing lock device is located in the non-operating position when the operator is not operating it as described above.
Is in the non-operating position, the closing stopper 17
Is in the locking posture, the connecting portion 1 of the closing connecting rod 10
0a is located on the left side of the long hole 8a (shown by a solid line in FIG. 11A), and the closing stopper 17 is in the standby posture,
The connecting portion 10a is located on the right side of the elongated hole 8a (see FIG. 11).
(A) is indicated by a one-dot chain line). In this case, when the front window 2 is located at the closed position, the closing stopper 17 is in the locking posture as described above, so that the connecting portion 10a of the closing connecting rod 10 has the elongated hole 8a. It is located on the left side. When opening the front window 2 from this state, first, when the closing lock device release lever 8 is operated to the right release position side in order to release the lock of the closing lock device 6, the connecting portion 10a becomes the elongated hole 8a. When it is located at the left part, it moves to the right along with the release lever 8 for the closing lock device (shown by a chain double-dashed line in FIG. 11 (A)), which causes the closing connecting rod 10 to move to the right and close. Stopper 17
Swing to the release posture. Thus, the rocking of the closing lock plate 16 toward the standby posture side is allowed, and the front window 2
Can be moved to the open position side,
At least the closing lock receiver 13 fits the front window 2 into the fitting groove 15
After moving to the closed position side until it comes out of a, when the release lever 8 for the close lock device is released, the release lever 8 for the close lock device swings to the left due to the urging force of the lever spring 26, Automatically returns to the non-operating position.
In this case, the closing connecting rod 10 moves leftward together with the closing lever 8 for the closing lock device.
The movement of 0 to the left is restricted when the closing stopper 17 is in the standby position in which it comes into contact with the lower surface of the closing lock plate 16, and thus the closing lever 8 for the closing lock device. When the stopper has returned to the non-operating position, the closing stopper 1
7 is in the standby position, and the connecting rod 10 for closing
The connecting portion 10a is located on the right side of the elongated hole 8a.

Thus, the release lever 8 for the closing lock device is
When the operator is not operating to the release side, the closing stopper 17 is always located in the non-operation position regardless of the locking posture or the standby stop posture. Then, when unlocking the closing lock device 6, the operator operates the closing lock device release lever 8 to the release position side, which is the same as the opening lock device release lever 9. Moreover, the operating directions of both the closing and opening release levers 8 and 9 toward the release side are set to be the same. Thus, the operator can use either the locking device 6 for closing or the locking device for opening.
Even when the lock of 7 is released, it is sufficient to always operate the release levers 8 and 9 for the closed lock device and the open lock device in the non-operated position to the release side. Only the release lever 8 or 9 of the device 6 or 7 may be operated to the release side, but the lock device 6 in the standby state
Alternatively, even if the release lever 8 or 9 of 7 is operated to the release side, the stand-by postures of the stopper 17 or 22 and the lock plate 16 or 21 are maintained.
9 may be operated to the release side at the same time. In the figure, 27 is a guide member for guiding the swing of the release lever 8 for the closing lock device.

By the way, when the release levers 8 and 9 for the closing lock device and the opening lock device are operated, the springs 18 and 24 for urging the closing and opening stoppers 17 and 22 and the lever spring 26 are operated. Since it is performed against the urging force, if both the release levers 8 and 9 are operated at the same time when the locking devices 6 and 7 for closing and opening are unlocked, only one release lever 8 or 9 is released. The operating force becomes heavier than when operating. Therefore, in the present embodiment, if it is desired to reduce the operating force as much as possible, it is sufficient to operate only the release lever 8 or 9 for unlocking,
Further, when it is troublesome to select the release levers 8 and 9 for releasing the lock, both release levers 8 and 9 may be operated at the same time.

Further, a guide cylinder 28 oriented in the left-right direction is attached to one end (right end in this embodiment) of the upper window frame 2a of the front window 2 in the left-right direction. A latch lock pin 29, which is slidably movable in the left-right direction, is inserted in this. The latch lock pin 29 grips a knob portion 29a fixed to the latch lock pin 29 and slides the latch lock pin 29 in the left-right direction, so that one end side of the latch lock pin 29 projects from the left and right side portions of the front window 2. It is adapted to be displaced to a lock position and a lock release position where the front window 2 is recessed inward of the left and right side portions. Further, the guide cylinder 28 is provided with engagement grooves 28a and 28b which engage with each other when the latch lock pin 29 is located at the lock position and the lock release position by rotating the knob portion 29a around the axis. By engaging the knob portion 29a with the engagement groove 28a or 28b, the latch lock pin 29 at the lock position and the lock release position is fixed so that it does not move accidentally. Has been done.

On the other hand, on the cab 1 side, there is formed a fitting hole 30 into which the latch lock pin 29 at the lock position is fitted when the front window 2 is located at the closed position and the open position. Then, when the front window 2 is positioned at the closed position and the open position, the knob portion 29a is operated to operate the latch lock pin 2
By sliding 9 to the lock position and fitting it into the fitting hole 30, the front window 2 is double-locked by the lock by the latch lock pin 29 and the lock by the automatic locking device 12 described above. It has become.

In the structure as described above, when opening and closing the front window 2 located at the closed and open positions, the release levers 8 and 9 for the close lock device and the open lock device are opened and closed. When operated to the release position side, the locks 6 and 7 for closing and opening are released and the front window 2 can be opened and closed. In this case, the operation of the release levers 8 and 9 is Since the operation can be performed by one-touch operation of the thumb of the hand while holding the handle 5A, the operability is excellent and the front window 2 is provided immediately after the opening lock device 7 is unlocked.
It is possible to surely eliminate the problem that the car suddenly slips off. Moreover, the release levers 8 and 9 for the closing lock device and the opening lock device are always located in the non-operating position when the operator is not operating the lock levers 6 and 7 when unlocking the lock devices 6 and 7. However, since the operation direction to the release side is the same direction, the operator does not get lost in the operation direction, which contributes to further improvement in operability. Besides,
As for the operation of the release levers 8 and 9 to the release side, as described above, only the release lever 8 or 9 for unlocking may be operated, or both the release levers 8 and 9 may be operated simultaneously. However, in the release levers 8 and 9, the open lock device release lever 9 is located on the upper side and the close lock device release lever 8 is located on the lower side when the front window 2 is in the closed position. The upper and lower parts are arranged side by side in parallel with each other. As a result, the position of the front window 2 and the position of the release lever 8 or 9 to be operated coincide with each other, and the release lever 8 or 9 for unlocking is released.
In the case of operating only one, there is an advantage that the operator can easily recognize which release lever 8 or 9 should be operated without making a mistake.

Further, the locking devices 6 and 7 for closing and opening.
Are attached to the front window 2 side, so the cab 1
It is not necessary to secure a space for disposing the lock device behind the front window 2 in the open position as in the case where the lock device is disposed at the rear part of the ceiling, and the vertical dimension of the front window 2 can be set to a large extent accordingly. As a result, it is possible to contribute to the expansion of the forward field of view during work. Also, when assembling the lock devices 6 and 7, it is easier to assemble to the front window 2 than to assemble to the cab 1. Further, the lock devices 6 and 7 assembled to the front window 2 are Since it can be covered with the cover 31 from the indoor side, it is excellent in appearance.

Further, in this structure, the front window 2 at each of the closed and open positions has a structure in which it is doubly locked by the automatic lock device 12 and the latch lock pin 29.
The lock at each position can be secured. In addition, the lock operation of the latch lock pin 29, that is, the latch lock pin 29 protruding from the front window 2 side is performed by the cab 1.
The lock device 6, 7 is inserted into the insertion hole 30 on the side.
Because it will be done after the automatic lock by
It is possible to check whether or not the automatic lock is reliably performed, and since the front window 2 is positioned at the closed and open positions by the automatic lock, the latch can be performed without troublesome alignment. The lock pin 29 and the fitting hole 30 are naturally aligned with each other.
The lock operation of the latch lock pin 29 can be easily performed.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a cab.

FIG. 2 is a front view of a front window viewed from the outside of the cab.

FIG. 3 is an enlarged cross-sectional view taken along line XX of FIG.

FIG. 4 is a plan view of a front window viewed from the inside of the cab.

FIG. 5 is a side view of a front window.

6A and 6B are a plan view and a side view of the automatic locking device when the front window is in the closed position.

7A and 7B are a plan view and a side view of the automatic locking device when the front window is in the open position.

FIG. 8 is a perspective view of a lock receiver for opening and closing.

9 (A) and 9 (B) are diagrams showing the operation of the opening locking device.

FIG. 10 is a view showing the operation of the closing lock device.

11A and 11B are diagrams showing the operation of the closing release lever and the opening release lever.

[Explanation of symbols]

1 cab 1a Window opening 2 front window 5 handles 6 Locking device for closing 7 Opening lock device 8 Release lever for closing lock device 9 Release lever for open lock device 12 Automatic locking device 13 Lock receiver for closing 14 Open lock receiver 16 Lock plate for closing 17 Stopper for closing 21 Lock plate for opening 22 Stopper for opening 29 Latch lock pin 30 Fitting hole

Continued front page    (72) Inventor Masanori Hayashi             7-14 Wadamiyadori, Hyogo-ku, Kobe-shi, Hyogo             Issue Nishiryo Engineering Co., Ltd. F-term (reference) 2D015 EA03                 3D127 AA09 CB07 CC02 DF02

Claims (5)

[Claims] 1. A front window that is openable and closable between a closed position for closing a window opening on the front side of a cab and an open position for storing the window opening in a cab ceiling, and closing and opening the front window. In a cab provided with each locking device for closing and opening for locking at each position of, and a handle provided on the front window for gripping when opening and closing the front window,
In each of the closing and opening locking devices, the lock body provided on the front window side is engaged with the lock receiving body provided on the cab side as the front window is positioned at each of the closing and opening positions. While closing the front window automatically at each position, for closing,
A cab characterized in that release levers for the closing lock device and the opening lock device for respectively releasing the locks of the opening lock devices are arranged in a portion that can be operated by fingers of the hand holding the handle. Front window locking device. 2. The front window locking device for a cab according to claim 1, wherein the handle is attached to a side surface portion of the front window. 3. The unlocking lever for the closing lock device and the opening lock device according to claim 1, wherein the operating directions for unlocking the locking devices for closing and opening are the same. A front window lock device for the cab. 4. The release lever for the closing lock device or the opening lock device according to claim 1, wherein the opening lever for the opening lock device is located at the upper side when the front window is in the closed position. A front window lock device for a cab, wherein the release levers for a lock device are arranged side by side in a vertical direction with the release levers located on the lower side. 5. The front window according to claim 1, further comprising a lock pin that can be retracted and retracted from a side surface portion of the front window, and the cab side has a front window closed position and an open position. A front window lock device for a cab, characterized in that a fitting hole into which the lock pin can be fitted is provided when the cab is located at the front position.