JP5410457B2 - Driver's cabin pressure rise prevention device - Google Patents

Description

  The present invention relates to an apparatus for preventing an increase in atmospheric pressure in a cab, and is particularly suitable as an apparatus for preventing an increase in pressure in an cab (cab) in a working machine such as a hydraulic excavator.

  In the cab of a work machine such as a hydraulic excavator, since airtightness is required, the airtightness in the room is increasing, and the air pressure in the cab increases instantaneously when the door is closed. The door is less likely to close, making it easier to enter a half-door state.

  Therefore, as shown in Patent Document 1, a limit switch for detecting the opening / closing operation of the door in the cab of a work machine such as a hydraulic excavator is provided, and when the opening operation of the door is detected, a ventilation port for ventilating the cab is provided. A half-door prevention device has been proposed in which the damper of the damper device that opens and closes is opened so as to prevent the pressure in the cab from rising during the door closing operation and a half-door state.

  Moreover, as shown in Patent Document 2, a vehicle interior pressure rise prevention device for preventing a half-door state even in a vehicle such as a passenger car has been proposed. The vehicle interior pressure rise prevention device disclosed in Patent Document 2 is provided with a fan and a flow path switching valve inside a flow path pipe communicating between the interior and the exterior of the vehicle interior, and the acceleration sensor detects a door opening operation start state. The flow path switching valve is automatically switched to the direction of discharge of the inside air, and when the acceleration sensor detects the door closing operation start state, the fan rotates to discharge the inside air of the vehicle interior. Is.

JP 2004-142667 A JP 10-147139 A

  Any of the above conventional operating room pressure rise prevention devices must be provided with a limit switch and an acceleration sensor for detecting the opening / closing operation of the door, and further, the damper of the damper device is opened or the flow path switching valve is switched. It was necessary to discharge the inside air of the passenger compartment by rotating the fan.

As described above, the conventional device requires a limit switch and an acceleration sensor, and also requires power to operate a damper, a flow path switching valve, and a fan, which complicates the configuration of the operating chamber pressure rise prevention device. There was a problem.
An object of the present invention is to obtain an apparatus for preventing an increase in atmospheric pressure in a driver's cab with a simple configuration and without requiring any special power.

  In order to achieve the above-described object, the present invention provides a cab having an entrance / exit, a door that is rotatably provided in the cab and opens / closes the entrance / exit, and is provided in the cab while taking in outside air. An air conditioner that supplies conditioned air, and prevents an increase in air pressure in the operating room that instantaneously increases when the door is closed, wherein the air conditioner is an intake air that contains a blower A box, an outside air duct for taking outside air into the suction side of the blower of the intake box, an outside air introduction damper for opening and closing the intake box side opening of the outside air duct, and the blower suction side of the intake box An internal air intake for taking in air in the cab, an internal pressure discharge passage communicating the intake box and the external air duct, and a pressure difference between the internal pressure discharge passage And a pressure reducing valve that automatically opens and closes and discharges the air in the intake box to the internal pressure discharge passage, and the pressure reducing valve is opened due to an increase in the pressure inside the cab due to the closing operation of the cab door. It is configured to be able to be discharged to the outside through the internal pressure discharge passage.

In the above-described operating room air pressure rise prevention device, the outside air duct is provided with an outside air filter on the outside air inlet side, and the outside air duct side opening of the inside air pressure discharge passage is disposed so as to face the outside air filter. Good.
In addition, a communication hole is formed in the outside air introduction damper provided in the intake box side opening of the outside air duct, and the inside air pressure discharge passage connecting the intake box side and the outside air duct side is attached to the communication hole. A pressure reducing valve may be provided in the internal pressure discharge passage.
The pressure reducing valve includes a valve seat provided on the intake box side in the internal pressure discharge passage, a valve body pressed against the valve seat, and a pressing unit that presses the valve body toward the intake box side. It is better to configure.

  According to the present invention, the internal pressure discharge passage is provided so as to communicate between the inside of the air intake box of the air conditioner that communicates with the cab and the inside of the outside air duct that takes outside air into the air conditioner. The pressure reducing valve that automatically opens and closes and discharges the air in the intake box to the internal pressure discharge passage is provided, so that when the pressure inside the cab increases due to the closing operation of the cab door, the pressure reducing valve Since the air is automatically opened and the inside air is discharged to the outside through the inside air pressure discharge passage, it is possible to prevent the air pressure in the cab from rising above a predetermined value. Therefore, there is an effect that it is possible to obtain a driver's cabin pressure rise prevention device that has a simple configuration without being complicated and that does not require special power.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall view showing a hydraulic excavator to which a first embodiment of an apparatus for preventing an increase in atmospheric pressure according to the invention is applied. It is a front view which expands and shows the cab (cab) in FIG. It is sectional drawing which looked at the cab from the direction of arrow III-III in FIG. It is a detailed top view which shows the air conditioning apparatus shown in FIG. 3 in a partial cross section. It is a figure explaining Example 2 of this invention, and is a figure equivalent to FIG.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an apparatus for preventing an increase in atmospheric pressure according to the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where it is applied to a hydraulic excavator.

  A first embodiment of the apparatus for preventing an increase in atmospheric pressure of the operating room of the present invention will be described with reference to FIGS. 1 is an overall view showing a hydraulic excavator to which Embodiment 1 of the present invention is applied, FIG. 2 is an enlarged front view showing a cab in FIG. 1, and FIG. 3 is a cab in FIG. FIG. 4 is a detailed plan view showing a partial cross section of the air conditioner shown in FIG. 3.

  In FIG. 1, reference numeral 1 denotes a hydraulic excavator as a construction machine. The hydraulic excavator 1 is mounted on a crawler type lower traveling body 2 capable of self-propelling as shown in FIG. The upper revolving body 3 and the work device 7 are roughly configured.

The upper swing body 3 of the hydraulic excavator 1 has a swing frame 4 constituting a frame of a construction machine. On the swing frame 4, a cab (cab) 10 and a position behind the cab 10 are located. A building cover 5 that houses a prime mover, a hydraulic pump (not shown), and the like, and a counterweight 6 that is located on the rear side of the building cover 5 are provided.
The working device 7 provided at the front part of the upper swing body 3 is provided at the center of the front part of the swing frame 4 so as to be able to move up and down, and performs excavation work such as earth and sand using a bucket 7A, for example.

  As shown in FIGS. 1 to 3, the cab 10 includes a cab box 11, a door 21, a floor plate 22 (see FIG. 3) that covers the cab box 11 from below. Further, as shown in FIG. 3, a driver's seat 23, operation lever devices 24 and 25, an air conditioner 26 and the like are provided inside the cab 10.

  The cab box 11 that forms the outer shell of the cab 10 is formed in a box-shaped box structure as shown in FIGS. 2 and 3, and includes an upper surface portion 12 that covers the upper side, a front surface portion 13 on the front side, and a rear rear surface. It has the side part 15 and 16 located in the surface part 14 and right and left both sides.

  Of the side surface portions 15 and 16 of the cab box 11, one side surface portion 15 located on the left side when viewed from the rear of the vehicle is operated in the left and right directions of the upper swing body 3 (vehicle body) as shown in FIG. Located on the side opposite to the apparatus 7, a door 21 for an operator to get in and out of the cab 10 is provided on the side surface portion 15.

  The side surface portion 15 is configured as a hollow structure by joining two panels 15A and 15B (hereinafter referred to as an outer panel 15A and an inner panel 15B) made of thin steel plates or the like by means of spot welding or the like. Has been.

  Further, as shown in FIG. 3, a front pillar 17 and a rear pillar 18 are provided on the side surface portion 15 of the cab box 11 so as to be separated from each other, and between the front pillar 17 and the rear pillar 18. A center pillar 20 is provided. An entrance / exit 19 serving as a door opening is formed between the front pillar 17 and the center pillar 20 on the side surface 15 of the cab box 11. The entrance 19 is opened / closed by a door 21. The

  On the other hand, between the rear pillar 18 and the center pillar 20, a window glass 15C forming a part of the side surface portion 15 is attached as shown in FIGS. Further, as shown in FIG. 2, the side surface 15 of the cab box 11 is provided with an outside air inlet 32, an inspection cover 33 and the like at a position below the window glass 15C.

  Note that the other side surface portion 16 located on the right side of the cab box 11 is configured by joining the front pillar 17 and the rear pillar 18 with a single panel.

  As shown in FIG. 3, the center pillar 20 is formed as a hollow structure between the outer panel 15 </ b> A and the inner panel 15 </ b> B, and extends in the vertical direction at the rear side position of the entrance / exit 19. Further, the center pillar 20 is formed with a hinge attachment portion 20A having a substantially L-shaped cross section, and a hinge 37 is attached to the hinge attachment portion 20A by means such as bolts or welding.

  That is, the center pillar 20 extends in the up-down direction at an intermediate portion in the front-rear direction of the cab box 11 (side surface portion 15), and the front side of the center pillar 20 is an entrance / exit 19 and the rear side is an outside air inlet 32. . A lift door 21 and an inspection cover 33 are attached to the hinge 37 so as to be openable and closable. The door 21 includes a door frame 21A formed by joining two metal panels and the like, a window glass 21B attached to the inside of the door frame 21A, and the like.

The floor plate 22 constituting the floor of the cab 10 is attached to the front surface portion 13, the rear surface portion 14 and the lower ends of the left and right side surface portions 15 and 16 of the cab box 11, and covers the cab box 11 from below. Is.
The operation lever devices 24 and 25 provided on the left and right sides of the driver's seat 23 are provided with operation levers 24A and 25A for controlling the operation of the work device 7 and the like.

  In FIG. 3, 26 is an air conditioner provided in the driver's cab box 11 at the rear side of the driver's seat 23, and this air conditioner 26 is provided for cooling inside as shown in FIGS. Unit evaporator 27, a heater core (not shown) for heating, etc., a blower 28 for circulating air in the unit case 27, and a suction side of the blower 28. The outside air duct 29 and a filter case 30 provided at the front end side of the outside air duct 29 and having an outside air filter 31 detachably attached thereto, and the like.

One side of the filter case 30 is fixed to the inner panel 15B of the side surface portion 15 constituting the cab box 11 by means of welding or the like, and the other side of the filter case 30 is connected to the outside air duct 29. It is connected to the inflow side (tip side).
The air blower 28 of the air conditioner 26 causes the air sucked from the outside air duct 29 and the inside air inlet 40 (see FIG. 4) to flow to the evaporator or heater core in the unit case 27, and the cooled or heated air is sent to the unit. The air is blown out from the air outlets 27A and 27B of the case 27 into the cab 10.

  The outside air filter 31 is detachably attached to the filter case 30 and circulates into the outside air duct 29 in a state in which outside air is purified (dust in the outside air is removed). The outside air filter 31 is provided with a locking claw (not shown) and the like, and the outside air filter 31 is mounted in the filter case 30 in a retaining state.

  When the outside air filter 31 is attached to or removed from the filter case 30, it can be performed by an operator or the like by opening the inspection cover 33 provided on the side surface portion 15 of the cab box 11. The filter 31 can be maintained, inspected and replaced.

  As shown in FIG. 2, the inspection cover 33 is formed with a plurality of slit-like outside air intake holes 33 </ b> B that are elongated in the vertical direction, and the outside air taken in from these outside air intake holes 33 </ b> B is passed through the outside air filter. It is distributed toward 31.

  In FIG. 2, 34 is a door catcher provided on the side surface portion 15 of the cab box 11 to hold the door 21 in the fully open position, and 35 is a hook provided so as to protrude outward from the door 21. The hook 35 is locked to the door catcher 34 when the door 21 is fully opened, whereby the door 21 is held in a fully open state. The door catcher 34 is attached below the window glass 15C and above the inspection cover 33, and the hook 35 is attached to the door frame 21A below the window glass 21B of the door 21.

Next, the detailed structure of the air conditioner 26 in a present Example is demonstrated with reference to FIG.
In the figure, reference numeral 40 denotes an inside air inlet for taking air inside the cab into the air conditioner 26, 41 denotes an inside air filter provided in the inside air inlet 40, and the inside air filter 41 removes dust by the inside air filter 41. In a clean state, the air is taken into the intake box 42 of the air conditioner 26, mixed with the outside air taken in from the outside air filter 31 through the outside air duct 29, and sucked into the blower 28. The air sucked into the blower 28 is blown into the unit case 27 and is cooled or heated by an evaporator or a heater core in the unit case 27. The cooled or heated air is configured to be blown out into the cab from an air outlet 27A provided on the upper surface of the unit case 27 and an air outlet 27B provided on the front side.

  In FIG. 4, reference numeral 43 denotes an outside air introduction damper provided on the outside air duct 29 side of the intake box 42 to open and close the intake box side opening of the outside air duct 29, in which outside air is introduced into the intake box 42 for air conditioning. It is closed when air conditioning is performed by circulating only inside air.

  44 is an internal pressure discharge passage provided so as to communicate the inside of the intake box 42 and the outside air duct 29, and 45 is an air provided in the intake pressure box 42 on the side of the internal pressure discharge passage 44. The pressure reducing valve 45 is configured to open and close by a pressure difference between the pressure on the intake box 42 side and the pressure on the outside air duct 29 side. The pressure reducing valve 45 includes a valve seat 45a provided on the intake box 42 side in the internal pressure discharge passage 44, a valve body 45b pressed by the valve seat 45a, and the valve body 45b on the intake box 42 side. There is provided a pressing means 45c that presses to the right. In this embodiment, the pressing means 45c is constituted by a coil spring. However, the valve body may be pressed by a leaf spring or other elastic member, or the valve body 45b itself may be elastic. What is necessary is just to make it press.

  With this configuration, when the door 21 of the cab 10 is closed, the pressure in the cab increases and a pressure acting on the valve body 45b of the pressure reducing valve 45 when the pressure exceeds a predetermined pressure, for example, 180 Pa. However, it overcomes the pressing force of the coil spring (pressing means) 45c, opens the pressure reducing valve 45, and the air in the cab 10 is the inside air filter 41, the intake box 42, the inside air pressure discharge passage 44, the outside air duct 29, and the outside air filter. It is discharged to the outside through 31.

  That is, the inside of the intake box 42 is communicated with the cab 10 through the inside air inlet 40, and is also communicated with the atmosphere side (outside) through the inside air pressure discharge passage 44. Therefore, the inside air pressure discharge passage 44 is opened and closed. By configuring the pressure reducing valve 45 to automatically open due to the pressure rise (pressure difference) in the intake box 42, the inside air is discharged to the outside via the inside pressure discharge passage 44, and the pressure inside the cab is increased. Can be prevented from rising above a predetermined pressure.

  Therefore, according to this embodiment, when the air pressure in the cab 10 rises due to the closing operation of the door 21 and the air pressure in the cab 10 exceeds the set pressure of the pressure reducing valve 45, the air in the cab is converted into the air conditioner. Since the air is automatically discharged to the outside through the internal pressure discharge passage 44 provided in the engine 26, it is possible to prevent the atmospheric pressure in the cab from rising above the set pressure value. Thereby, it can prevent that the door 21 of a cab becomes difficult to close and it will be in a half door state. In addition, there is an effect that it is possible to prevent an uncomfortable feeling due to an instantaneous increase in the air pressure in the cab.

  Furthermore, according to the present embodiment, the outside air duct side opening of the inside air pressure discharge passage 44 is provided so as to face the outside air filter 31. Thereby, when the air in the cab is blown to the outside from the internal pressure discharge passage 44 during the door opening and closing operation, the air is blown to the outside air filter 31 of the air conditioner. Thus, it is possible to eliminate the need for cleaning the outside air filter of the air conditioner and to increase the cleaning interval, and to improve the maintainability.

  In the present embodiment, the pressure reducing valve 45 has been described as having a valve body pressed against the valve seat by the pressing means. However, the pressure reducing valve 45 is a pressure inside the operating room (including a pressure difference between the inside air and the outside air). As long as the air pressure rises above a predetermined value, it can be automatically opened and can release the air in the cab to the outside.

  FIG. 5 is a view for explaining a second embodiment of the apparatus for preventing increase in atmospheric pressure of the operating room according to the present invention and corresponds to FIG. 5, the same reference numerals as those in FIG. 4 denote the same or corresponding parts.

  In the first embodiment, the example in which the internal pressure discharge passage 44 is provided so as to penetrate the intake box 42 and the outside air duct 29 has been described. However, in the second embodiment, the opening on the intake box 42 side of the outside air duct 29 is opened and closed. The outside air introduction damper 43 is used, and a communication hole 47 is formed in the outside air introduction damper 43. The communication hole 47 is formed of a cylindrical member, and discharges the internal pressure connecting the intake box side and the outside air duct side. A passage 44 'is attached. The internal pressure discharge passage 44 'is provided with a pressure reducing valve 45 similar to that in the first embodiment. Since other configurations are the same as those in the first embodiment, the description thereof is omitted.

  Also in the second embodiment, when the pressure inside the cab 10 rises due to the closing operation of the door 21 and the pressure inside the cab 10 exceeds the set pressure (for example, 180 Pa) of the pressure reducing valve 45, the air in the cab is changed. Since the air is automatically discharged to the outside through the intake box 42 of the air conditioner 26 and through the internal air pressure discharge passage 44 provided in the outside air introduction damper 43, the air pressure in the operating room rises above the set pressure. Can be prevented. Therefore, there is an effect that it is possible to prevent the driver's cab door 21 from being closed and a half-door state, or the atmospheric pressure in the driver's cab to rise instantaneously and cause discomfort.

  Further, according to the present embodiment, it is not necessary to form the inner pressure discharge passage 44 ′ by forming a hole in the intake box 42 or the outside air duct 29. Therefore, when the air conditioner 26 is assembled, the inner pressure discharge passage 44 ′ is assembled. Is attached to the valve plate of the outside air introduction damper 43 in advance, there is an effect that the operating room pressure rise prevention device of the present embodiment can be configured very easily.

  As described above, according to each of the embodiments of the present invention described above, in order to prevent the pressure in the cab from rising during the door closing operation and becoming a half-door state, It is not necessary to provide a limit switch or an acceleration sensor for detecting the opening / closing operation, and it is not necessary to operate a damper, a flow path switching valve, or a fan. Therefore, it is possible to obtain a driver's cabin pressure rise prevention device that has a simple configuration without being complicated and that does not require special power.

1: hydraulic excavator, 2: lower traveling body, 3: upper turning body, 4: turning frame,
5: Building cover, 6: Counterweight, 7: Working device,
10: cab (cab), 11: cab box, 19: boarding gate,
21: Door, 22: Floor board, 23: Driver's seat, 24, 25: Operation lever device,
26: Air conditioner, 27: Unit case, 27A, 27B: Air outlet,
28: Blower, 29: Outside air duct, 30: Filter case, 31: Outside air filter,
33: Inspection cover, 33B: Outside air intake hole,
40: Inside air intake port, 41: Inside air filter, 42: Intake box, 43: Outside air introduction damper,
44, 44 ': Internal pressure discharge passage,
45: Pressure reducing valve (45a: valve seat, 45b: valve body, 45c: pressing means).

Claims (4)

A driver's cab having an entrance / exit, a door that is rotatably provided in the operator's cab and opens and closes the entrance / exit, and an air conditioner that is provided in the driver's cabin and supplies conditioned air into the room while taking outside air, An apparatus for preventing an increase in atmospheric pressure in the operating room that prevents an increase in atmospheric pressure in the operating room that instantaneously increases when the door is closed,
The air conditioner includes an intake box containing a blower, an outside air duct for taking outside air into the suction side of the blower of the intake box, and an outside air introduction damper for opening and closing the intake box side opening of the outside air duct, An internal air intake for taking in the air in the operating room to the blower intake side of the intake box, an internal pressure discharge passage communicating the inside of the intake box and the outside air duct, and pressure in the internal pressure discharge passage A pressure reducing valve that automatically opens and closes due to the difference and discharges the air in the intake box to the internal pressure discharge passage;
The pressure-increasing valve is opened by an increase in the pressure inside the cab due to the operation of closing the cab door, and the inside air can be discharged to the outside through the internal pressure discharge passage. apparatus.   2. The apparatus for preventing an increase in atmospheric pressure according to claim 1, wherein an outside air filter is provided on the outside air duct on an outside air inlet side, and an outside air duct side opening of the inside air pressure discharge passage is arranged to face the outside air filter. An apparatus for preventing an increase in atmospheric pressure in a driver's cab is provided.   2. The operating room pressure rise prevention device according to claim 1, wherein a communication hole is formed in the outside air introduction damper provided on the outside air duct side of the intake box, and the intake box side and the outside air are formed in the communication hole. An apparatus for preventing an increase in atmospheric pressure in a driver's cab, wherein an internal pressure exhaust passage connecting the duct side is attached, and a pressure reducing valve is provided in the internal air pressure exhaust passage.   2. The apparatus for preventing an increase in the atmospheric pressure of the operating room according to claim 1, wherein the pressure reducing valve includes a valve seat provided on an intake box side in the internal pressure discharge passage, a valve body pressed against the valve seat, and the valve An apparatus for preventing an increase in atmospheric pressure in a driver's cab, comprising pressing means for pressing a body toward the intake box.

Images