JP3027767B2 - Air circulation system in enclosed area - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air circulation system, and more particularly to a system for environmentally regulating air circulating in a cab of a vehicle.

BACKGROUND OF THE INVENTION In the operation of modern construction vehicles, noise in the cab, to which operators are exposed, has become an increasingly important problem. A major source of noise in the cab is the heating, ventilation and air conditioning systems commonly referred to as HVAC. The noise in these systems is due to a number of factors, including multiple motors, that are used to operate the blower fan and to operate the blower fan at a certain speed to obtain sufficient airflow in the cab. Is caused. These criteria are often due to the amount of restriction formed by the duct through which the air flows, and as a result,
This is due to the pressure drop formed at the inlet and outlet sides of the blower assembly. As the throttle in the system increases, so does the pressure drop formed on the inlet and outlet sides of the blower.
The greater the pressure drop, the higher the fan speed must be to create a sufficient amount of airflow to effectively ventilate the cab. An alternative is to use multiple blowers to increase airflow, all of which have the adverse effect of increasing the amount of noise created by the heating and air conditioning systems.

In many cases, the amount of throttle formed in the system is a function of the available space in which many components and ducts are located. For example, it is always desirable to mix fresh air outside the cab with air circulating in the cab. In many cases, there is not enough room to place a dedicated duct to bring fresh air into the system. As a result, it is very common to utilize the tubular frame already present in the cab structure as a duct for taking fresh air into the system.
While this is a very efficient use of space and available components, it creates a relatively tortuous path for fresh air flow and increases the amount of throttling in the system. An example of this type of design is December 12, 1982
U.S. Patent No. 4,36, issued to Marques et al.
No. 5,541.

Another source of throttling disclosed in the Marques et al. Patent is to place filters for fresh air and circulating air. Again, because space is at a premium, filters for air from the two sources are located in the same area to improve maintainability. These filters are generally arranged in a common housing in linear alignment with one another. A filter for fresh air is arranged upstream of the circulating air filter, leaving a relatively small space between the two filters. This space serves as an inlet for circulating air to be introduced into the air flow drawn through the heating and air conditioning unit by activating the blower. Obviously, the entrance is so small that a relatively large throttle is formed. As a result, multiple blowers or a single blower with very high fan speed are required to provide sufficient airflow to the system. This condition will result in increased noise while the system is operating.

The present invention seeks to overcome one or more of the problems described above.

DISCLOSURE OF THE INVENTION According to one aspect of the present invention, there is provided an air circulation system for regulating an environment in an enclosed area. The system includes a housing located within the enclosed area and having first and second portions. Means are provided for communicating outside air outside the ambient air into the first portion of the housing.
Means are also provided for communicating air circulating in the enclosed area to the first portion of the housing and mixing with ambient air. Means are provided for discharging air from the housing defining a plurality of discharge ports (discharge ports) remote from the housing. The system further includes a blower assembly having a motor and a pair of fan members rotatably connected on opposite sides of the motor.
A blower assembly is located in the second portion of the housing and draws a sufficient amount of environmentally acceptable mixed air from the first portion of the housing into the inlet portion and directs it through the outlet portion to the outlet port. Air pressure at the outlet of the blower is 0.398-
It is determined in advance to be large within the range of 0.439 KpA.

According to another aspect of the invention, the air circulation system is suitable for use in a cab of a vehicle. The air circulation system has first and second compartments and an opening defined in a housing for communicating air circulating in the cab to the first compartment. A pair of fresh air passages are provided on opposite sides of the cab, each having a first end portion defining an opening. The second of the air passage
The end portions are respectively engaged on both sides of the first compartment. The fresh air passage allows outside air outside the cab to communicate with the first compartment of the housing. The system includes an air duct assembly having a first end portion positioned to communicate with a second compartment of the housing, the second end portion having at least one air exhaust port. . A blower assembly is provided that has an inlet portion and an outlet portion, draws ambient air and circulating air in the cab into the first compartment, and returns the circulating air into the cab through a discharge port.
The pressure drop of the blower assembly between the inlet and outlet sections is in the range of 0.398 to 0.439 KpA.

According to yet another aspect of the invention, an air circulation system is included in a cab of a vehicle having a seat mounted on a base of the vehicle to provide a location where an operator can control the vehicle. The system includes a housing having an air intake portion and an air release portion and mounted to a base to form a mounting platform for the seat. An air intake port is defined by the housing on the rear side of the seat, and air circulating in the cab is communicated with the air intake portion of the housing. A filter assembly is mounted to the housing in an overlapping relationship with the air intake port. Means are provided for discharging air from a discharge portion of the housing, the discharge means for directing air flow from a pair of laterally spaced openings defined in the discharge portion of the housing in front of the seat. And a plurality of discharge ports (discharge ports) laterally separated from each other by a distance substantially equal to the width of the sheet. The system includes a blower assembly having a motor and a pair of fan members located on opposite sides of the motor. The blower assembly is located in the discharge portion of the housing such that the fan members are aligned with respective openings defined in the discharge portion of the housing. The blower draws air through the filter assembly and the inlet portion of the housing into the outlet portion of the housing, and then pressurizes the air between the outlet port and the filter in a generally circular pattern around an operator sitting on the seat. The air is directed to the discharge port through the discharge means so that the air circulates therebetween.

The present invention provides an air circulation system that allows air from outside and inside the cab to be drawn into the blower housing with minimal restriction formed in the ducts of the system. Similarly, the duct that directs air to the vent, which introduces conditioned air from the blower housing into the cab, also has relatively no restriction. This reduced throttle on the air flow provides a greatly reduced air pressure difference between one side of the blower and the other. Thus, an air circulation system having a combination of these factors using a single motor and a pair of fans provides a sufficient amount of airflow in the cab to maintain a satisfactory working environment under all circumstances. It is understood that it is possible. Since the number of blowers utilized and the speed of the fans are kept to a minimum, the noise generated by the operation of the system of the present invention is greatly reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of a vehicle cab having an air circulation system incorporating the principles of the present invention; FIG. 2 is a schematic plan view taken along line 2-2 of FIG. 1 is a schematic rear view of the air circulation system, taken along line 3-3 in FIG. 1, showing the structure of the cab in phantom for reference purposes; FIG. 4 is the front left position of the operator shown in FIG. FIG. 2 is a perspective view of the air circulation system as viewed from above.

Referring to the drawings, there is shown a cab 10 that provides an enclosed area from which a construction vehicle (not shown) can be operated. The cab 10 is formed by a plurality of tubular frame members 12 secured together by means such as welding to form a skeletal structure of the enclosed area. The skeletal structure provides support for the first and second side walls 14, 16 located on the right and left sides of the enclosed area, as well as the front wall 20 and the rear wall 18.
The walls of the enclosed area consist of a sheet metal frame fitted with a plurality of windows (FIG. 1) to provide good visibility for the operator. A door is provided on at least one side wall of the cab 10 to allow the operator to enter and exit the cab.
24 are provided.

The operator (shown in phantom in FIG. 1) is the operator's cab
It is located on a seat 26 provided in a substantially central portion of 10. The sheet is supported by a horizontally extending base member 28 between the lowermost tubular frame members 12. The housing 30 formed by the base member 28 forms a platform to which the seat 26 is fixed.

The housing 30 forms part of an air circulation system 32 (FIG. 4) that provides an environmental conditioning of the air in the cab 10 in addition to providing a platform on which the seat 26 is mounted. The housing 30 is divided into two parts 34,36. The first part 34 forms an air intake compartment that houses an air conditioning unit 38 that controls the cab environment. In the description of this embodiment, the term "air conditioning" is used in the broadest sense and means that it applies to any treatment of air, such as heating, cooling, dehumidification and the like. The second portion 36 of the housing 30 forms a discharge compartment in which the blower assembly 40 is located in a manner described below. The two compartments 34, 36 are separated by a common wall 42 having an opening 44 that allows the passage of air drawn through the air conditioning unit 38.

Means for communicating the air outside the cab with the air intake portion of the housing is indicated generally by the numeral 46. The outside air communication means 46 includes first and second air passages 48 and 50 extending between opposed side walls 14 and 16 of the cab 10, and a pair of opposed sides 52 and 54 of the housing 30. The first air passage 48 extends between the right side wall 14 and the wall 52 formed by the housing 30. The second air passage 52 is formed between the left side wall 16 and the housing 30.
And a wall 54 formed on the opposite side. First
Since the second air passages 48 and 50 have the same configuration, the same reference numerals are given to the same components as much as possible. As indicated by the thin arrows indicating the air flow, outside air flows through openings 56 formed in the side walls 14 and 16 of the cab.
1 (FIG. 1) is introduced into each air passage 48, 50 and enters a first cavity member 58 defined on a first end portion 59 of each air passage 48, 50. The first hollow member 58 is mounted on the side wall in a substantially vertical direction. To remove impurities from the air entering the first cavity member, a filter member 60 is mounted in a relationship covering the opening 56 in the side wall of the cab. A second cavity member 61 is located below the first cavity member 58 and extends generally horizontally inwardly and is coupled to the housing 30 at a second end portion 62 defined by the air passages 48 and 50. I have. A first opening 64 is located along the outer edge 66 of the second cavity member 61 between the first and second cavity members 58 and 61 and has substantially its full width as seen in FIGS. It has been extended over. A second opening 68 defines the wall 52 and
Formed in 54 and coupled to second cavity member 61 and housing 30. The second opening 68 is such that the second cavity member 61 is not laterally aligned with the opening 64 between the first and second cavity members.
It is located at the rear. Each of the first and second cavities is provided with a suitable sound-suppressing material (not shown) to absorb a significant portion of the noise entering the air passage through openings 56 formed in the outer side wall of the cab. Lining).

An inlet 70 is formed in the upper wall 72 of the first housing part 34 and serves as a means for introducing air circulating in the cab 10 into the first housing part 34. The recirculated air, indicated by the thick arrows, is mixed with fresh air before being drawn into the air conditioning unit 38. A filter 74 is positioned in overlapping relationship with the recirculated air inlet 70 to remove particles from the air as it enters the first housing portion 34. Filter 74 is very large in size relative to a conventional filter used in such an application. In the present embodiment, the filter 74
Is approximately 1481 cm ² . The filtration medium used for the filter is a high density microglass fiber.

Means for discharging air from the second portion 36 of the housing 30 back into the cab is indicated generally by the numeral 76. Release means 76
Is attached to the housing 30 and extends forward from the housing. Discharge means 76 includes a pair of laterally spaced, horizontally deployed ducts 78 and 80 having a first end 82 connected to a forward facing wall 84 of the housing. A pair of openings 86 and 88 are formed in the wall 84 and are laterally separated from each other by a distance corresponding to the spacing between the discharge ducts 78 and 80 to allow air communication between the housing 30 and the duct. I have. Each of the ducts 78 and 80 has a second end portion that is laterally larger than the first end portion 82 to form a taper from the first end portion 82 to the second end portion 90, respectively. Has 90. The second pair of ducts 92 and 94 have a first end portion 96 connected to the second end portion 90 of the first pair of ducts 78 and 80, respectively. The second pair of ducts 92 and 94 are the first pair of ducts 78 and 80
And extends in a substantially vertical direction. The second pair of ducts 92 and 94 terminate at a second end portion 98 substantially equal in height to the lower portion 100 of the seat 26 (FIG. 1). A number of discharge ports or vents are mounted at a number of locations around the second end portion of each duct. Each vent is individually adjustable to direct air flow in a plurality of desired directions. A first vent 102 is provided for the second pair of ducts 92 and 94.
Of the driver's cab 10, facing the window 22 defined by the side walls 14 and 16 of the cab 10. A pair of second ventilation holes 105 are provided on the upper surface 1 of each of the second pair of ducts 92 and 94.
06 and is adjustable to direct the flow of air toward the cab windshield (not shown). A pair of third ventilation holes 110 extending downward from the upper surface 106 and located on an inclined surface facing the operator;
Provides airflow in that direction. A fourth vent 114 is located on the interior wall 116 of each of the second pair of ducts 92 and 94 and directs airflow inwardly and toward the operator's feet when the operator is seated on the seat 26. Point downward.

The blower assembly 40 described above is mounted in the discharge portion 36 of the housing 30. The blower assembly 40 includes one motor 1 located between a pair of fan housings 120.
Driven by 18. As seen in FIGS. 2 and 3,
A fan member 122 is located within each housing 120 and is rotatably mounted on a common shaft 124 that extends into the fan housing 120 from the end of the motor 118. Fan housing 120 is laterally spaced by a distance corresponding to the spacing between openings 86 and 88 formed in front wall 84 of housing 30. A fan 122 is located near openings 86 and 88 so that air moves directly from outlet 126 of fan housing 120 into first pair of ducts 78 and 80.

Industrial Applicability In the operation of the air circulation system 32 described above, the outside air and the air circulating in the cab 10
The housing 30 is rotated by rotation of a fan 122 provided in the housing 30.
Is sucked into the first part or the intake chamber. The outside air outside the cab 10 is drawn into the first hollow member 58 through fresh air filters 60 provided on both sides 14 and 16 of the cab. This air then flows into the first cavity member 58 and the second cavity member.
The suction is sucked from the first cavity member 58 into the second cavity member 61 through the opening 64 formed between them. The opening 64 is relatively large and extends over almost the entire width of the first cavity member 58, so that air is introduced into the second cavity member 61 with little restriction. Force from the blower assembly 40 draws air diagonally across the second cavity member 61 into an opening 68 formed between the second cavity member 61 and the first housing portion 30. Again, the second cavity member 61 is formed in a wide, flat rectangular shape, so that the air moves between the two openings 64 and 68 with little restriction. It should be noted that the presence of an air flow that is hardly restricted may promote noise transmission through the system. However, as described above, the first and second openings 64 and 68 in the second cavity member 61 are laterally offset from each other. With this positioning, the noise entering the second hollow member 61 tends to move straight across the second hollow member, and
Noise can be contained in the hollow member 61. In this way, most of the noise is directed not toward the opening 68 of the housing 30 but toward the facing wall of the second hollow member 61. Since the cavity member is lined with a sound-suppressing substance, noise is significantly attenuated in the second cavity member and is not transmitted into the housing.

When the blower fan 122 is rotated, air is sucked into the inlet chamber 34 through the filter 74 and the inlet 70 formed in the upper wall 72 of the housing 30. Due to the particular composition of the filter material and the large size of the filter 74 and the opening 70 through which the air passes, the restriction to the flow of air from within the cab 10 is also kept to a minimum.

Air from within the first portion 34 of the housing 30 is selectively treated by being drawn through an air conditioning unit 38 and then drawn into the second or discharge portion 36 of the housing 30. The conditioned air then flows into the fan housing
Aspirated during 120 and directed under pressure to the first pair of discharge ducts 78 and 80. Since the first pair of discharge ducts 78 and 80 are located in close proximity to each fan housing 120, air is directly introduced into the first pair of discharge ducts. First
Duct pairs 78 and 80 are tapered as they extend toward second end portion 90 so that little turbulence occurs when air moves through the ducts. The air is then directed upwardly into a second pair of discharge ducts 92 and 94 forming a smooth connection with the first pair of ducts 78 and 80. Air is selectively directed into the cab 10 by discharge vents 102, 104, 110 and 114 located in front of the operator. Since most of the vents are directed upward and backward, and the recirculation filter 74 is located just behind the seat 26, the airflow in the cab naturally follows a circular pattern around the operator. , Recirculation filter 74
Will return to.

By providing the air circulation system 32 as described above, a very quiet and environmentally sufficient selectively regulated air flow can be provided in the cab 10 of the vehicle. Fresh air and recirculated air are drawn into the system via air passages that have no throttling action on the mostly passing air. At the same time, air is discharged into the cab via an air passage which also has little throttle action. Due to the reduced restriction on air flow, the pressure drop between the air entering the discharge compartment 36 and the air discharged into the first pair of discharge ducts 78 and 80 is in the range of 0.398 to 0.439 KpA. This alleviates the conditions required for the blower assembly 40 to eventually move air through the air conditioning system. Since the blower assembly 40 utilizes only one motor 118 and a pair of relatively slow-rotating fans 122, operating the blower assembly produces very little noise in the cab.

Other aspects, objects, and benefits of the present invention can be obtained from a study of the drawings, the description and the appended claims.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-27618 (JP, A) JP-A 64-11815 (JP, U) US Patent 4612975 (US, A) US Patent 4088364 (US, A) US Patent No. 4503749 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60H 1/00 102

Claims (18)

(57) [Claims] An air circulation system (32) suitable for use in a cab (10) of a vehicle, defined by first and second compartments (34, 36) and a housing (30). A housing (30) having an inlet (70) for communicating circulating air in the cab (10) to the first compartment (34); respectively, in opposite sides (14, 16) of the cab (10). A first end portion (59) defining an opening (56) and a second end portion (62) engaging the opposing sides (52, 54) of the first compartment (34). A pair of fresh air passages (48, 50) for communicating outside air outside the cab (10) to the first compartment (34); and to a second compartment (36) of the housing (30). A first end portion (82) disposed and a second end having at least one air discharge port (102, 104, 110, 114); Air duct means having a portion (90) (78,8
0) and; the outside air and the air circulating in the cab (10), which is arranged in the second compartment (36), is sucked into the second compartment (36) through the first compartment (34), and Air discharged from the second compartment (36) rather than air sucked into the compartment (36),
An air circulation system (32) comprising: a blower assembly (40) directed back through the discharge ports (102, 104, 110, 114) into the cab (10) at a large predetermined pressure in the range of 0.398 to 0.439 KpA. 2. Each of the pair of fresh air passages (48, 50) is formed on each side wall (14, 16) of the cab (10) around an opening (56) formed in the cab (10). An attached generally vertically extending first cavity member (58); having first and second openings (64,68), and having an outer portion (6
6) further comprising a substantially horizontally extending second cavity member (61) located below the first cavity member (58) and extending inwardly of the housing (30); An opening (64) in communication with said first cavity member (58) and said second opening (68) is located in communication with a first portion (34) of the housing (30). Air circulation system (32). 3. The second cavity member (61) is laterally spaced apart from each other and has first and second openings (64, 6) positioned substantially at both ends.
8) forming a substantially rectangular parallelepiped chamber having
As a result, the outside air sucked by the blower assembly (40) passes through the first opening (64) communicating with the first hollow member (58), traverses the cuboid chamber, and communicates with the first housing part (34). An air circulation system (32) according to claim 2, which flows to (68). 4. The first and second compartments (34, 36) defining an opening (44) for allowing air to pass therethrough.
An air conditioning unit (38) for environmentally treating the air as it flows from the first compartment (34) of the housing (30) to the second compartment (36). An air circulation system (32) according to any of the preceding claims, wherein the air circulation system (32) is provided in the second compartment (36) of the housing (30) adjacent to the housing. 5. The air circulation system (3) according to claim 1, wherein the seat (26) is mounted on the housing (30).
2). 6. An air circulation system (32) according to claim 5, wherein the inlet (70) defined by the housing (30) is centrally located behind the seat (26). 7. A filter medium comprising a high density micro-glass fiber, wherein a filter assembly is disposed in overlapping relationship with an inlet defined by a housing. And an air circulation system (32) according to claim 1, having a filtration area of approximately 1481 cm ² . 8. A cab (10) comprising: a filter assembly (60);
Disposed in overlapping relation with the openings (56) formed by the fresh air passages (48, 50) in the side walls (14, 16) of the filter assembly, the filter assembly (60) being made of high density micro glass fiber. a filter medium comprising an air circulation system according to claim 1, wherein has a filtration area of schematic 431cm ² (32). 9. A pair of air duct means (78, 80) extending forward from the first end portion (82) to have a gradually increasing flow area over the enlarged second end portion (90). The air circulation system (32) according to claim 1, including a duct (78,80). 10. The air duct means (78, 80) forms a laterally extending taper between the first end portion (82) and the second end portion (90) and increases substantially uniformly. The air circulation system (32) of claim 9, providing a flow area. 11. The air duct means (78, 80) includes a first end portion (96) engaged with a second end portion (90) of the first pair of ducts (78, 80), and a plurality of discharge ports. (102,104,110,114)
A second end pair (92, 94) having a second end portion (98) defining the second duct pair (92, 9).
4) is deployed in a substantially vertical direction and discharge ports (102, 104, 11)
0,114) the front wall (18) defined by the cab (10)
The air circulation system (32) according to claim 9, wherein the air circulation system (32) is arranged at a position adjacent to the air circulation system. 12. The discharge port (102, 104, 110, 114) is located at a height substantially equal to the height of the sheet (26) and is centrally located behind the sheet (26) in a substantially circular path from the discharge port (102, 104, 110, 114). The air circulation system (32) according to claim 5, wherein the air circulation system (32) is arranged to discharge air to the inlet (70). 13. A base portion (28) and a base portion (28).
An air circulation system (32) for use in a cab (10) of a vehicle having a seat (26) supported by the vehicle and providing a position for an operator controlling the vehicle, comprising a first compartment (34) and a second compartment. A housing (30) attached to the base portion (28) to form a mounting platform for the seat (26); and a rear of the seat (26) defined by the housing (30). An inlet (70) for communicating air circulating in the cab (10) to the first compartment (34) of the housing (30); and in opposing side walls (14, 16) of the cab (10). Opening to (56)
And a first end portion (59) defining opposite sides (52, 54) of the first compartment (34) of the housing (30).
And a second end portion (62) engaged with the cab (10).
A pair of fresh air passages (48,50) arranged in substantially horizontal alignment with said housing for mixing the atmosphere outside of the housing with air circulating in the cab (10); A filter assembly (74) mounted on the housing (30) in overlapping relationship with the housing (30); and a pair of laterally spaced openings (86,88) defined in the second compartment (36) of the housing (30). ) With a plurality of discharge ports (102, 104, 110, 11) disposed in front of the sheet (26) and laterally spaced from each other by a distance at least substantially equal to the width of the sheet (26).
Means (76) for discharging air from the second compartment (36) of the housing (30), which are positioned to communicate with 4); one motor (118) and located on both sides of the motor (118). A pair of fan members (122)
Is aligned with the openings (86,88) defined in the second compartment (36) of the housing (30).
A blower assembly (40) mounted in a second compartment (36) of the filter assembly;
4) and through the inlet (70) suck air into the second compartment (36) of the housing (30) and sit in the seat (26) between the discharge ports (102, 104, 110, 114) and the filter (74). Discharge ports (102,104,110,114) through discharge means (76) for discharging air under pressure so as to circulate air in a substantially circular pattern around the operator
Air circulation system (32). 14. The housing (3) in support relationship with an opening (56) defined in the housing.
0) a first duct having a first end portion (82) connected to the second compartment (36) and a second end portion (90) and extending from the housing (30) in a substantially horizontal direction. A first end portion (96) connected to the second end portion (90) of the first duct pair (78,80); and a plurality of discharge ports (102,10).
4,110,114) having a second end portion (98) attached thereto and extending upwardly from the first pair of ducts (78,80) to form a minimum restriction to air flowing therethrough. 2. The method of claim 1 further comprising two duct pairs.
The air circulation system according to item 3 (32). 15. A pair of first and second ducts (78,80,92,94) defined by a first duct pair (78,80) defining a progressively increasing taper extending forward. The air circulation system (32) of claim 14, wherein the air circulation system (32) forms a flow transition region having substantially no throttle. 16. A plurality of discharge ports (78, 80, 92, 94) further for directing air flow outwardly toward windows (22) located on opposite sides (14, 16) of the cab (10). At least one discharge port (102) for directing air to the interior of the cab (10); and at least one discharge port (104) for directing air toward the interior portion of the cab (10); At least one discharge port (110) directed upwardly toward the directed forward facing windshield (22); and a flow of air is defined by the operator sitting in the seat (26) and the cab (10). Formed rearward facing window (2
An air circulation system (32) according to claim 13, including at least one discharge port (114) directed rearward and upward towards 2). 17. The air circulation system (32) according to claim 16, wherein each discharge port (102, 104, 110, 114) is individually adjustable in air flow direction. 18. The blower assembly (40) has a predetermined pressure greater than the pressure of the air sucked into the second compartment (36) of the housing (30) within a range of 0.398 to 0.439 KpA. 14. The air circulation system (32) according to claim 13, wherein the air is directed via a).