JPH09221791A - Front window opening and closing device in the cab - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To effectively utilize a constant torque spring force to reduce an operating force when the front window is opened, and to open the front window opening / closing device and the constant torque spring and a drive motor when the front window is opened. As a result, the drive motor is downsized. SOLUTION: One end is attached to left and right lower end portions of a front window 2, and the other end is wound by being wound on take-up drums 9a and 9b attached to upper left and right front columns 1a and 1b of a cab. The front window 2
Is provided with constant torque springs 8a and 8b for urging the springs in the opening direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front window opening / closing device for a driver's cab of a construction machine such as a hydraulic excavator or a crane vehicle, and more particularly to a front window opening / closing device with reduced operation force when opening and closing the front window.
Also, the present invention relates to an automatic front window opening / closing device for automatically opening and closing the front window.

[0002]

2. Description of the Related Art Conventional construction machines such as hydraulic excavators and crane trucks are used for checking the ground during work, for responding directly to auxiliary workers, and for obtaining good ventilation and visibility in the cab. In addition, the front window of the cab can be opened. This is a guide rail provided from the front pillar side to the ceiling surface of the cab, and with the front window of the cab pulled out toward you, lift the front window upwards and follow the guide rail to the ceiling surface. I am trying to move it to a state parallel to. Such an operation is manually performed by the driver, and the operator holds the handles attached to the upper and lower sides of the front window. However, since the front window weighs about 20 kg, the operation weight is heavy and the opening / closing operation cannot be easily performed. Further, the guide rail provided on the ceiling surface from the front portion of the operator's cab is formed in a substantially L shape, and it is difficult to smoothly move the bent portion. Further, there is a problem that the driver has to open and close the front window in a middle waist posture.

In order to solve such a problem, the applicant has filed an application in Japanese Utility Model Application Laid-Open No. 5-34009. As shown in FIG. 17, the contents of this application include a front window 52 which is attached to the left and right front pillars 53a and 53b of the operator's cab 51 and is openably and closably attached to the guide rails 55a and 55b. Ceiling guide rails 56a and 56b extending from the guide rails 55a and 55b and provided on the left and right edges of the ceiling frame 54, and an upper guide roller rotatably attached to the left and right side surfaces of the front window 52. 57a, 57c and lower guide rollers 57b, 57d, and these guide rollers 57a, 57b, 57c, 57d are engaged with the guide rails 55a, 55b, 56a, 56b to bring the front window 52 to the front of the cab 51. Is a front window opening / closing device for a driver's cab that is slidable from the ceiling to the ceiling. One end is horizontally attached to the ends of the upper guide rollers 57a and 57c, and the other end is wound up. Strip of the constant torque spring 58a to attach arm 59a, to 59b, and 58b, the winding drum 59a, 59
In b, the front window 52 is attached to the ceiling partition wall in front of and above the positions of the upper guide rollers 57a and 57c when the ceiling portion is housed, and the front window 52 is opened by the force of the constant torque springs 58a and 58b. The configuration is described to reduce the pushing force at the time.

Further, the applicant has filed an application in Japanese Patent Application Laid-Open No. 7-138988. The content of this application is a work in which a window moving along a guide rail formed between a front pillar and a top plate portion of a cab of a working vehicle is provided with a lock mechanism for pressing the front pillar to close the window. An automatic window opening / closing control device for a vehicle driver's cab, wherein the lock mechanism advances and retreats with respect to the window and closes or uncloses the window, a lock motor that advances and retracts the lock member, and the lock member. And a buffer member provided on at least one of the stopper portion and the lock member, and when the load current of the lock motor exceeds a predetermined value, A configuration including a control unit that outputs a stop signal is described. A drive cable for raising and lowering the window is connected to the window. The drive cable is constructed so as to form a closed loop as a whole. One end is connected to the shafts of the guide rollers at the lower left and right of this window, extends to the rear of the operator's cab along the guide rails, and extends downward through the guide rails on the opposite side. It is folded back through the reversing pulley provided on the above and is connected to the shaft portion of the guide roller. The drive cable is provided with a drive unit including a gear and an elevating motor to allow the drive cable to move around. That is, a part of the drive cable is a gird cable for the circular movement. The gear of the drive unit is adapted to mesh with the upper and lower geared cables.

[0005]

However, the front window opening / closing device for the driver's cab described in Japanese Utility Model Laid-Open No. 5-34009 has the following problems. (1) The take-up drum that horizontally attaches the front end of the constant torque spring to the upper guide roller shaft of the front window and winds the rear end is
Since it is attached to the rear end of the ceiling guide rail and to the bulkhead of the ceiling frame, the contracting force of the constant torque spring acts almost horizontally in the front-rear direction, so the pulling force when the front window is opened works effectively. do not do. (2) Further, it is necessary to dispose a winding drum of a constant torque spring on the ceiling frame of the operator's cab and to provide the ceiling frame with slit-shaped holes for the stroke in order to enable the constant torque spring to stroke. The strength of the cab is reduced. (3) Further, since the winding drum of the constant torque spring is mounted at the rear end of the ceiling guide rail and in front of the position of the front window upper guide roller that houses the front window, horizontal movement that requires the most spring effect. Immediately before the end, since the spring acts on the tension side, the operating force for opening the front window becomes large.

Further, in the automatic window opening / closing control device and the window opening control method for the working vehicle driver's cab described in JP-A-7-138988, the vehicle body is tilted because the drive cable is connected to the lower guide roller shaft. The front window is difficult to move up and down when Further, since the front window raising / lowering drive cable is formed of a closed loop, the structure is complicated and the manufacturing cost is increased.

In the present invention, focusing on the above problems, by changing the mounting position of the constant torque spring, the spring force is effectively utilized to reduce the operating force when the front window is opened and the strength of the cab. It is an object of the present invention to provide a front window opening / closing device for a driver's cab, which has a structure that does not lower the temperature, and an automatic front window opening / closing device for a driver's cab that is opened by a constant torque spring and a drive motor when the front window is opened.

[0008]

In order to achieve the above-mentioned object, the front window opening / closing device of the first cab according to the present invention is provided on the left and right front columns and the ceiling frame in front of the cab. A front window opening / closing device for a driver's cab, which is provided with a front window that can be opened and closed along a guide rail. One end is attached to the left and right lower end portions of the front window 2, and the other end is the left and right front columns 1a. , 1b are wound on the winding drums 9a and 9b attached to the upper portions of the windshields 1b and 1b, and have constant torque springs 8a and 8b for biasing the front window 2 in the opening direction. . According to the above configuration, one end is attached to the left and right lower end portions of the front window, and the other end is locked to the winding drum attached to the upper portions of the left and right front columns, so that the contracting force of the constant torque spring is always increased. It works by acting in the direction. Therefore, the constant torque spring effectively acts on pulling up when the front window is opened, and the operating force is reduced. Further, unlike the conventional case, it is not necessary to provide a slit-shaped hole for the stroke of the constant torque spring in the ceiling frame of the cab, so that the strength of the cab is not reduced. Further, since the constant torque spring makes a stroke in the guide roller rolling groove, it is always surrounded by the groove and the front window, or is housed in the winding drum, so it is not exposed to the outside. Since it is not damaged, it has improved durability.

Further, in the above structure, the constant torque springs 8a and 8b are attached to the connecting fitting 12b in abutment with each other. According to the above configuration, the connection fitting 12b
Serves as a detent, and the constant torque springs 8a and 8b are rotated so as not to shift laterally. Therefore, the constant torque springs 8a and 8b do not stick out to the outside and are damaged, so that the durability is improved.

A second front and rear window opening / closing device for a driver's cab according to the present invention includes a front window attached to the left and right front columns in front of the driver's cab and a guide rail provided on a ceiling frame so as to be freely opened and closed. A front window opening / closing device for a driver's cab, comprising: driving means for driving a guard cable locked to the front window, and operating means 4 for selecting an operation of the front window 2 in an opening direction or a closing direction.
7, the guard cables 31a, 31b locked to the upper end of the front window 2, and the guard cables 31a, 31
Drive means 40 for driving b to operate the front window 2 in the opening direction or the closing direction, one end is attached to the left and right lower end portions of the front window 2, and the other end is attached to the left and right front columns 1a and 1b. Constant torque springs 8a and 8b that are wound by being wound on the winding drums 9a and 9b, and the front window 2 from the operating means 47 are operated by receiving an operation signal in the opening direction or the closing direction, and the operation result is obtained. And a control device 46 for outputting a command signal to the drive means 40 based on the above. According to the above configuration, the driving means for driving the guard cable locked to the upper end of the front window, one end is attached to the left and right lower end portions of the front window, and the other end is attached to the left and right front columns. And a constant torque spring that is wound around the take-up drum and is wound, so that when the front window is moved in the opening direction by the driving means, the contracting force of the constant torque spring acts upward to move the front window. The opening can be done smoothly. Therefore, the opening operation of the front window can be surely performed even when the vehicle body is tilted, and the driving means can be downsized by using the constant torque spring, so that the cost can be reduced.

Further, in the above construction, the shut-off means 21a, 21b for holding the front window 2 in the shut-off direction and the operation means 47 for operating the front window 2 in response to the shut-down direction operation signal are calculated, and the calculation result is obtained. And a control device 46 for outputting a command signal to the shutoff means 21a, 21b based on the above. According to the above configuration, the front window closing means is activated by receiving an operation signal for opening or closing direction of the front window from the operating means, so that the front window can be surely opened and closed.

Further, in the above construction, the constant torque springs 8a and 8b are constructed such that the pulling force is set variably with respect to the pulling amount. According to the above configuration, since the constant torque springs 8a and 8b assist the pulling force of the front window in the opening direction, the operating force can be reduced.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a front window opening / closing device for a driver's cab according to the present invention will be described below with reference to the drawings. The hydraulic excavator 20 equipped with the operator's cab of the present invention will be described with reference to FIG. A turning circle 22 is provided above the undercarriage 21.
The upper revolving structure 23 is disposed via the. The upper swing body 23 includes a boom 31, an arm 33, and a bucket 3.
5 are sequentially connected, and the working machine 30 driven by each hydraulic cylinder 32, 34, 36 is attached. The cab 1 is placed in front of the upper swing body 23. When excavating work by driving the working machine 30 of the hydraulic excavator 20, in order to confirm the ground during the work, to directly respond to an auxiliary worker, and to obtain good ventilation and visibility in the cab 1. For this reason, the front window of the operator's cab 1 is opened for work. The present invention facilitates opening of the front window and simplifies the structure.

A first embodiment of a front window opening / closing device for a driver's cab of the present invention will be described with reference to FIGS. 2 to 10. still,
Similarly to the one described in FIG. 17, the front window is clamped by the guide rails provided on the left and right front pillars of the operator's cab and is openably and closably attached, extends from the left and right guide rails, and the ceiling frame. The structure is the same as the structure in which the front window is slidable from the front of the operator's cab to the ceiling by providing ceiling guide rails provided on the left and right edges. First, the cab 1 shown in FIG. 2 and FIG.
The front window 2 is stored between the right front pillar 1a and the left front pillar 1b. Upper rollers 7 are provided on the left and right upper ends of the front window 2.
a and 7c are attached. The lower roller 7d and one end of the right constant torque spring 8b are attached to the lower right end of the front window 2. The other end of the right constant torque spring 8b is locked and wound by a winding drum 9b attached to the upper portion of the right front pillar 1a. The lower roller 7b and one end of the left constant torque spring 8a are attached to the lower left end of the front window 2. The other end of the left side constant torque spring 8a is connected to the left side front pillar 1
The winding drum 9a attached to the upper part of b is locked and wound.

The front window 2 is, as shown in FIG.
Is slidable from the front to the ceiling, and the figure shows the closing position of the front window 2. Indicates a state in which the front window 2 is operated in the opening direction or the closing direction. Indicates the open position where the front window is stored in the ceiling.

Next, the Z view of FIG. 4 will be described with reference to FIG. The bracket 1e is attached to the upper part of the right front pillar 1a. The winding drum 9b is attached to the bracket 1e. The right constant torque spring 8b is locked and wound around the winding drum 9b. A guide rail 5b is provided on the right front pillar 1a, and a ceiling guide rail 6b extending from the guide rail 5b is provided. A winding drum 9a is also attached to the left front pillar 1b on the opposite side (not shown) as in FIG. 5, and similar guide rails 5b and 6b are provided from the left front pillar 1b to the ceiling.

The section AA of FIG. 4 will be described with reference to FIG. The right constant torque spring 8b is arranged between the right front column 1a and the front window 2. Left side constant torque spring 8 not shown
Similarly, a is also disposed between the left front pillar 1b and the front window 2. In this way, the constant torque springs 8a and 8b are not exposed to the outside.

Next, the section BB of FIGS. 7 and 7 will be described with reference to FIG. The tip of the right constant torque spring 8b abuts the connection fitting 12b and is attached by a screw. As a result, the connecting fitting 12b serves as a detent and the identifying torque spring 8b is prevented from rotating and shifting laterally. The left constant torque spring 8a also has a similar structure, and a description thereof will be omitted. It is connected to the lower guide roller shaft 11b through this connecting fitting 12b. The other end of the torque spring 8b is wound around the winding drum 9b described with reference to FIG. The lower guide roller 7b is rotatably attached to the guide roller shaft 11b fixed to the bracket 14b, and the bracket 14b is attached to the front window 2. Further, the tip of the left constant torque spring 8a on the opposite side (not shown) is also connected to the lower guide roller shaft through a connecting fitting as in FIG. 7, and the lower guide roller is rotatably attached to the guide roller shaft fixed to the bracket. The bracket is attached to the front window 2. Next, the winding drum 9 attached to the upper portions of the front columns 1a and 1b shown in FIG.
A and 9b are fixed torque springs 8a and 8b locked and wound. The pulling force of the constant torque springs 8a and 8b is set to be variable with respect to the stroke.

Next, the operation of the first front window opening / closing device of the cab of the present invention shown in FIGS. 2 to 9 will be described. The front window 2 is slidable from the front surface of the operator's cab 1 to the ceiling so that it can be held at a closed position or an open position. Since the constant torque springs 8a and 8b are attached to the left and right lower end portions of the front window 2, the front window 2 always works in the upward direction by the contracting force of the constant torque spring, so that the front window 2 can be pulled up when opened. As shown in FIG. 10, the pulling force when the operator opens the front window 2 effectively acts on the front window 2 at the front window closing position A of the front window 2 as shown in FIG. According to the first embodiment of the present invention, the pulling force PB at the window opening position B is different from the pulling force P1 at the front window closing position A of the front window 2.
Is the same as the conventional one, but the pulling force P at the front window opening position B is
2, the operating force immediately before opening the front window, which requires a force to open the front window, is reduced. Therefore, the front window 2 can be easily opened.

Further, unlike the prior art, since it is not necessary to form the guide groove of the guide roller shaft in the partition wall of the ceiling frame of the cab, the strength of the cab is not reduced. Further, since the constant torque spring makes a stroke in the guide roller rolling groove, it is always surrounded by the groove and the front window, or is housed in the winding drum, so it is not exposed to the outside. There is no damage to it.

Next, a second embodiment of the front window opening / closing device of the cab of the present invention will be described with reference to FIGS. 11 to 16. Note that, as in the case described with reference to FIG. 17, the front window is sandwiched between the guide rails provided on the left and right front columns of the operator's cab and is openably and closably attached, and extends from the left and right guide rails. The front window can be slid from the front of the operator's cab to the ceiling by providing ceiling guide rails provided on the left and right edges of the ceiling frame, and the operator's cab and the front pillar of the first embodiment shown in FIGS. The winding drum and the like have the same structure and are omitted in the drawing.

First, the front window 2 shown in FIG. 11 is the first window shown in FIG.
Like the embodiment, it is housed between the right front pillar and the left front pillar. Upper rollers 7a, 7c are provided on the left and right upper ends of the front window 2.
I'm wearing The lower roller 7d and one end of the right constant torque spring 8b are attached to the lower right end of the front window 2. The other end of the right constant torque spring 8b has a winding drum 9 attached to the upper portion of the right front column as in the first embodiment shown in FIG.
It is locked and wound on b. The lower roller 7b and one end of the left constant torque spring 8a are attached to the lower left end of the front window 2. The other end of the left side constant torque spring 8a is wound and locked by a winding drum 9a attached to the upper part of the left front column, as in the first embodiment shown in FIG.

An upper roller 7a provided on the front window 2
Both the lever 32a and the lever 32a are pivotally supported. This lever 3
2a and one end of the guard cable 31a are connected.
Further, the upper roller 7c and the lever 3 provided on the upper part of the front window 2
2b and 2b are both pivotally supported. The lever 32b and one end of the guard cable 31b are connected. These geared cables 31 a and 31 b mesh with the gear 42. It is rotationally driven by driving a drive motor 44 directly connected to the gear 42. The drive of the drive motor 44 causes the guard cables 31a and 31b to move circularly, and the front window 2
It is possible to pull up. Further, the left and right constant torque springs 8a attached to the lower left and right ends of the front window 2,
8b is such that the contracting force of the constant torque spring acts upward when the front window 2 operates in the opening direction.

Next, lock motors 21a and 21b for closing the front window are provided at the upper left and right ends of the front window 2. By driving the lock motors 21a and 21b, the front window is pressed through the link to close the window, and details thereof will be described later with reference to FIGS. Drive motor 4 for moving the geared cables 31a, 31b in a circular manner
The driving means 40 composed of four gears 42 is connected to the control device 46 via a driving circuit 45. The left and right lock motors 21a and 21b are connected to the control device 46 via a drive circuit 48a. A rotation speed signal detected by the reed switch 33 that detects the rotation speed of the output shaft of the drive motor 44 is input to the control device 46. The operation signal of the operation means 47 for selecting the opening or closing of the front window 2 is input to the control device 46. The X view of FIG. 11 will be described with reference to FIG.

The shut-off mechanism 20 for the front window 2 of FIG. 14, which is a cross-sectional view taken along the line X--X of FIG. The shutoff mechanism 20 has the same structure as the right lock motor 21a, the left lock motor 21b, and the links. Here, the right lock motor 21a and the links 23a and 24a will be described.
The front pillars of the front window 2, the guide rails, etc. are the same as in the first embodiment, and will be described with reference to FIGS. 2 and 5. In FIG. 12, the lock motor 21a attached to the front window 2 is rotated in the normal direction to
Shows the state of releasing the deadline with the front columns 1a and 1b shown in FIG. FIG. 13 shows a closed state in which the lock motor 21a attached to the front window 2 rotates in the reverse direction and the front window 2 is pressed against the front columns 1a and 1b shown in FIG. The shutoff mechanism 20 for the front window 2 has the following configuration. Lock motor 21 on front window 2
a is attached. The lock motor 21a and one end of the first link 23a are rotatably attached by a pin 22a. The other end of the first link 23a and the second link 2
One end of 4a, one end of the lever 32a and the upper guide roller 7a are rotatably attached by a pin 25a.
The other end of the second link 24a is connected to the front window 2 by a pin 26a.
It is rotatably attached to the side of. The other end of the lever 32a is connected to the guard cable 31a. In this way, the lock motor 21 is normally rotated to release the front window 2 from the front columns 1a and 1b shown in FIG. 2, and then the drive means 40 shown in FIG. 11 is driven to drive the guard cable 31a.
The front window 2 can be pulled up to the open position along the guide rails 5b and 6b shown in FIG.

Next, the operation of the second embodiment shown in FIGS. 11 to 14 will be described. The gear cables 31a and 31b locked to the upper end of the front window 2 are engaged with the gear 42, and a drive motor 44 for driving the gear 42 is provided. One end is attached to the left and right lower end portions of the front window 2, And the other end is the front pillar 1 on either side.
Since the constant torque springs 8a and 8b are wound around the winding drums 9a and 9b attached to the a and 1b, the driving means 40 including the front window 2 and the gear 42 and the drive motor 44 is provided.
The constant torque springs 8a, 8
The contraction force of b works upward to open the front window 2 smoothly. As a result, the opening operation of the front window 2 can be reliably performed even when the vehicle body is tilted, and the drive motor 4 can be provided by using the constant torque springs 8a and 9a.
4 can be made small.

A control flowchart of the control device 46 shown in FIG. 11 will be described with reference to FIGS. First,
A control flowchart in the opening direction in which the front window 2 is housed in the ceiling from the front of the cab will be described with reference to FIG. S
1, the window operation switch 47 (hereinafter referred to as window regulator SW) is operated in the opening direction (UP, S).
W, ON). In S2, a command signal is output from the control device 40 to the lock motors 21a and 21b via the drive circuits 48a and 48b, and the lock motors 21a and 21b are driven to the left and right release sides for a predetermined time (t1). Next, in S3, the left and right lock motors 21a and 21b are turned off (drive is stopped).
To In this S3, the left and right lock motors 21a, 21b
Is turned off, the drive motor 44 is driven in the opening direction of the front window 2 in S4 to move the geared cables 31a and 31b meshed with the gear 42 in the F1 direction to open the front window 2 in the opening direction. Pull up. After that, in S5, it is determined whether the output shaft rotation speed of the drive motor 44 detected by the lead sensor 33 is a predetermined rotation speed. If the output shaft rotation speed does not reach the predetermined rotation speed, the process returns to S4 and the output is output. When the shaft speed reaches the predetermined speed, the drive motor 44 is turned off in S6.
Set to (stop driving). After confirming that the drive motor 44 is OFF, the lock motors 21a and 21b are driven to the left and right cutoff sides for a predetermined time (t2) in S7. Lock motor 2 at S8
After confirming that the left and right sides 1a, 21b are OFF (stopping driving), the operation is completed.

Next, a control flow chart in the closing direction from the open state in which the front window 2 is stored in the ceiling of the cab to the front pillar in front of the cab will be described with reference to FIG.
In S20, the window regulator SW is operated in the closing direction (DOWN, SW, ON). In S21, a command signal is output from the control device 40 to the lock motors 21a and 21b via the drive circuits 48a and 48b, and the lock motor 2
1a and 21b are driven to the left and right release side for a predetermined time (t3). Next, in S22, the left and right lock motors 21a and 21b are turned on.
Set to FF (stop driving). After the left and right lock motors 21a and 21b are turned off in S22, the drive motor 44 is driven to close the front window 2 in S23, and the gear 42
The geared cables 31a, 31b meshed with the are moved in the F2 direction to lower the front window 2 in the closing direction. After that, S24
It is determined whether the output shaft rotation speed of the drive motor 44 detected by the lead sensor 33 is a predetermined rotation speed. If the output shaft rotation speed does not reach the predetermined rotation speed, the process returns to S23, and the output shaft rotation speed is determined. When reaches the predetermined number of revolutions, the drive motor 44 is turned off (driving is stopped) in S25. Drive motor 4
After confirming that 4 is OFF, the lock motor 21
Drive a and 21b to the left and right cutoff sides for a predetermined time (t4). Then, in S8, the OF of the left and right lock motors 21a, 21b is set.
After confirming F (stop driving), the operation ends.

[Brief description of drawings]

FIG. 1 is a side view of a hydraulic excavator.

FIG. 2 is a perspective view illustrating a front window opening / closing device of a first cab of the present invention.

FIG. 3 is an explanatory diagram of an opened and closed state of a front window.

FIG. 4 is an explanatory diagram of a mounted state of the constant torque spring.

FIG. 5 is a Z view of FIG. 4;

FIG. 6 is a sectional view taken along line AA of FIG. 4;

FIG. 7 is an explanatory view of a state in which a constant torque spring and a lower roller are mounted in the same.

8 is a sectional view taken along line BB of FIG.

FIG. 9 is an explanatory view of a constant torque spring and a winding drum of the same.

FIG. 10 is a view comparing the front window pulling force of the first cab front window opening / closing device of the present invention with respect to the conventional structure.

FIG. 11 is an explanatory diagram of a front window opening / closing device of a second cab of the present invention.

FIG. 12 is an X view of FIG. 11, and is an explanatory view of a front window cutoff release state.

FIG. 13 is an explanatory diagram of a front window cutoff state of the same.

14 is a sectional view taken along line CC of FIG.

FIG. 15 is a flowchart of a front window opening operation of the same.

FIG. 16 is a flowchart of a front window closing operation of the same.

FIG. 17 is an explanatory diagram of a conventional front window opening / closing device for a driver's cab.

[Explanation of symbols]

 1 Driver's cab 1a Right front pillar 1b Left front pillar 2 Front window 5b Front pillar guide rail 6b Ceiling guide rail 7a, 7c Upper roller 7b, 7d Lower roller 8a, 8b Constant torque spring 9a, 9b Winding drum 21a, 21b Lock motor 23a 1st link 24a 2nd link 31a, 31b Guard cable 32a, 32b Lever 33 Lead sensor 40 Drive means 42 Gear 44 Drive motor 45, 48a, 48b Drive circuit 46 Control device 47 Operation means

Claims (5)

[Claims] 1. A front window opening / closing device for a driver's cab, comprising front left and right front pillars in front of the operator's cab and front windows that are attached so as to be openable and closable along guide rails provided on a ceiling frame.
Attached to the lower left and right ends of (2), and the other end to the left and right front columns
It is equipped with constant torque springs (8a, 8b) that are locked by the winding drums (9a, 9b) attached to the upper part of the reel to wind, and that bias the front window (2) in the opening direction. A front window opening and closing device for the driver's cab. 2. The constant torque springs (8a, 8b) are connected fittings (1
The front window opening / closing device for a driver's cab according to claim 1, wherein the front window opening / closing device is attached in contact with (2b). 3. A front window that is openably and closably attached along the left and right front pillars in front of the operator's cab and guide rails provided on the ceiling frame, and a drive means for driving the guard cable locked to the front window. In the operator's cab front window opening and closing device, the front window (2) is locked to the operation means (47) for selecting the operation in the opening direction or the closing direction and the upper end of the front window (2). The guard cable (31a, 31b) and this guard cable (3
1a, 31b) to drive the front window (2) in the opening direction or the closing direction, and the driving means (40), one end of which is attached to the left and right lower end portions of the front window (2) and the other end is left and right. Constant torque springs (8a, 8b) that are wound on the winding drums (9a, 9b) attached to the front columns (1a, 1b) of the, and the operation means (47) to the front window (2). )
Is operated by receiving an operation signal in the opening direction or the closing direction, and a controller (46) for outputting a command signal to the drive means (40) based on the operation result. Front window opening and closing device. 4. The shut-off means (21a, 21b) for holding the front window (2) in the shut-off direction, and the operation means (47) to the front window.
A control device (46) for calculating (2) in response to an operation signal in the cutoff direction and outputting a command signal to the cutoff means (21a, 21b) based on the calculation result. Item 3. A front window opening / closing device for a driver's cab according to Item 3. 5. The front of the cab according to claim 1, wherein the constant torque springs (8a, 8b) have a retracting force variably set with respect to a withdrawal amount. Window opening and closing device.