Door fixation boss

A heating, ventilation, and air-conditioning system for a vehicle includes a housing, a door supported by the housing, and a lock integral with the housing. The housing further includes a first air flow path and a second air flow path. The door moves between a first position blocking airflow from the first air flow path and a second position blocking airflow from the second air flow path. The lock is configured to automatically lock the door in the second position upon assembly of the housing.

FIELD

The present disclosure relates to heating, ventilation, and air-conditioning units, and particularly to a dedicated door control to block or allow air passage through a housing.

BACKGROUND

Heating, ventilation, and air-conditioning (HVAC) systems in vehicles, typically include an HVAC case or housing containing a heater core for heating airflow, and often including an evaporator for cooling airflow. The HVAC housing further includes a plurality of airflow control doors that are movable to open and close outlets through which airflow is routed through, and exits, the HVAC housing. For example, a housing may transport heated, mixed, or cooled air from the HVAC system in a front compartment of the vehicle to rear passenger outlets. The housing may route the air though various portions of the vehicle including, for example, the doors. However, when the features of various HVAC systems differ, for example systems providing rear heat/air-conditioning versus systems only having front heat/air-conditioning, different duct or housing systems are necessary. Having multiple options for duct or housing systems increases costs and complexity in manufacturing/assembly.

SUMMARY

An example embodiment of a heating, ventilation, and air-conditioning system for a vehicle according to the present disclosure includes a housing, a door supported by the housing, and a lock integral with the housing. The housing further includes a first air flow path and a second air flow path. The door moves between a first position blocking airflow from the first air flow path and a second position blocking airflow from the second air flow path. The lock is configured to automatically lock the door in the second position upon assembly of the housing.

In some example embodiments, the door may be fixed on a shaft for rotation within the housing, and the lock may include an aperture for receiving the shaft and rotationally fixing the shaft within the aperture.

In some example embodiments, the aperture may be a T-shaped aperture and the shaft may be a T-shaped shaft.

In some example embodiments, an inner wall of the aperture may include a chamfered step that engages a chamfered step of the shaft.

In some example embodiments, the chamfered step on the inner wall of the aperture may include a sloped edge.

In some example embodiments, an angle of the sloped edge relative to an insertion direction of the shaft may be 45 degrees.

In some example embodiments, the inner wall of the aperture may include a first chamfered step, a second chamfered step, and a third chamfered step to define a T-shape of the aperture.

In some example embodiments, each of the first chamfered step, the second chamfered step, and the third chamfered step may include a sloped edge.

In some example embodiments, an angle of the sloped edge for each of the first chamfered step, the second chamfered step, and the third chamfered step relative to an insertion direction of the shaft may be 45 degrees.

In some example embodiments, upon insertion of the shaft into the aperture, the engagement of the chamfered step of the shaft with the chamfered step of the inner wall may rotate the shaft to position and retain the door in the second position.

In some example embodiments, the first air flow path may be a cold air flow path and the second air flow path may be a hot air flow path.

An example embodiment of a housing for a heating, ventilation, and air-conditioning system according to the present disclosure includes sidewalls, a door supported by the sidewalls, and a lock integral with the sidewalls. The sidewalls define a first air flow path and a second air flow path. The door moves between a first position blocking airflow from the first air flow path and a second position blocking airflow from the second air flow path. The lock is configured to automatically lock the door in the second position upon assembly of the housing.

In some example embodiments, the door may be fixed on a shaft for rotation relative to the sidewalls, and the lock may include an aperture for receiving the shaft and rotationally fixing the shaft within the aperture.

In some example embodiments, the aperture may be a T-shaped aperture and the shaft may be a T-shaped shaft.

In some example embodiments, an inner wall of the aperture may include a chamfered step that engages a chamfered step of the shaft.

In some example embodiments, the chamfered step on the inner wall of the aperture may include a sloped edge.

In some example embodiments, an inner wall of the aperture may include a first chamfered step, a second chamfered step, and a third chamfered step to define a T-shape of the aperture.

In some example embodiments, each of the first chamfered step, the second chamfered step, and the third chamfered step may include a sloped edge.

In some example embodiments, upon insertion of the shaft into the aperture, the engagement of the chamfered step of the shaft with the chamfered step of the inner wall may rotate the shaft to position and may retain the door in the second position.

In some example embodiments, the first air flow path may be a cold air flow path and the second air flow path may be a hot air flow path.

DETAILED DESCRIPTION

Heating, ventilation, and air-conditioning (HVAC) systems commonly use housing or ducts to transport air throughout a cooled or heated space. For example, in vehicles, a housing or duct system may transport heated, mixed, or cooled air from the HVAC unit in a front compartment of the vehicle to rear passenger outlets. The housing may route the air though various portions of the vehicle including, for example, the doors. In some applications, the HVAC system may be designed such that a dedicated portion of heated, ambient, or cooled air will mix and be carried to the rear passenger outlet in the housing or duct system. A dedicated door control may be utilized to mix the air during rear HVAC control mode where the housing is designed to allow the door to move freely. Providing a locked rear air mix door may be a cost effective way to block off the rear path for vehicle variations without the rear HVAC variant, reducing part, assembly, and tooling costs.

One example of a locked rear-air-mix door includes a female T-cut on the case at an end of the door shaft hole. The existing rear mode door may then be used to seal the hot air inlet-to-rear path. The female T-cut holds the door in a single position by utilizing the door's male T-cut. The female T-cut is a part of, and integral to, the case and has a shape similar to that of an existing HVAC linkage. The female T-cut further contains features to allow the male T-cut on the door shaft to rotate into the proper position to fit during assembly. The female T-cut orientation is designed to close off the hot path to rear with the door. This design accomplishes a safe, pinch-free assembly, little to no risk for door packing to tear/rip during assembly, ease of install, and accurate, error-proof (poka-yoke) install. Additionally, this example allows the use of the same door on vehicle variants with and without a rear air-flow path, reducing costs and complexity during manufacture and assembly.

The housing is designed such that the inner surfaces of the female T-cut on the door insertion side are chamfered in a circular, or rotational, orientation to allow the door shaft male T-cut to slide into the female T-cut position. The chamfered inner surfaces of the female T-cut twist the door shaft male T-cut into position during assembly of the cases to remove any risk or need to position the door in the female T-cut manually. The female T-cut position forces the door to seal over the hot inlet-to-rear path identical to that of the driver linkage in max cold on the exiting cooled air. Sealing of the door to the rear path is indefinite due to the fixed nature of the female T-cut on the housing. Additionally, this design eliminates the need to create a separate part to hold the door in position, removing costs associated to tooling and sourcing of an extra part and complexity during assembly.

Referring toFIG. 1, a heating, ventilation, and air conditioning (HVAC) system in accordance with the present disclosure at reference numeral10. The HVAC system10may be configured for use with any suitable vehicle, such as any suitable passenger vehicle, commercial vehicle, mass transit vehicle, construction vehicle/equipment, military vehicle/equipment, recreational vehicle, watercraft, etc. The HVAC system10may also be configured for use with any suitable non-vehicular application as well.

The HVAC system10includes an HVAC housing, duct, or case14. An evaporator18and a heater core22are housed within the HVAC housing14. Although the HVAC system10is illustrated and described herein as including the evaporator18, the evaporator18is optional and may not be included in all applications.

The HVAC housing14defines a plurality of outlet ducts, through which airflow passes and exits the HVAC housing14and flows to various outlets of different zones of the vehicle through any suitable HVAC piping arrangement. An example portion of the housing26is illustrated inFIGS. 2 and 3.

The housing portion26inFIG. 2is designed to mix and carry air from the evaporator18and heater core22disposed in a front portion of the vehicle to rear passenger outlets. The housing portion26may be disposed in a door of the vehicle and controls mixing for the rear-control mode of the HVAC system10while allowing free movement of the vehicle door.

Referring additionally toFIG. 4, the housing portion26includes a rear air flow path30, a cold air flow path34, and a hot air flow path38defined by outer walls42and inner walls46of the housing14. The cold air flow path34may extend from the evaporator18to the rear air flow path30, and the hot air flow path38may extend from the heater core22to the rear air flow path30.

A rear air mix door50may control mixing of air from the cold air flow path34and air from the hot air flow path38as set by the rear controls. The rear air mix door50may be rotationally positioned at an intersection of the rear air flow path30, cold air flow path34, and hot air flow path38. The rear air mix door50may be fixed on a shaft54that is received in the outer walls42and/or inner walls46of the housing portion26of the HVAC system10.

In vehicles having rear-control mode, the rear air mix door50may move between, and be fixed at any point between, a first position completely blocking air flow from the cold air flow path34and a second position completely blocking air flow from the hot air flow path38. When the rear air mix door50is fixed in the first position, air from the hot air flow path38, and heater core22, heats a rear compartment of the vehicle through the rear air flow path30and rear passenger outlets. When the rear air mix door50is fixed in the second position, air from the cold air flow path34, and evaporator18, cools the rear compartment through the rear air flow path30and rear passenger outlets. When the rear air mix door50is fixed in any position between the first position and the second position, the air from the cold air flow path34mixes with the air from the hot air flow path38to create mixed air that is transported to the rear passenger outlets through the rear air flow path30.

In some circumstances, such as when the vehicle does not have rear-control mode of the HVAC system10, it is necessary to block the hot air flow path38, only allowing air flow from the cold air flow path34. To block the hot air flow path38, the rear air mix door50may be locked in the second position.

Now referring toFIGS. 4-11, the housing portion26may include a lock58to immovably fix the rear air mix door50in the second position. For example, the lock58may include a female T-cut aperture62(FIGS. 5 and 6) in the outer wall42of the housing portion26that engages with a male T-cut66(FIG. 8) on the shaft54of the rear air mix door50.

As shown best inFIGS. 5-7, the outer wall42of the housing portion26includes the aperture62for receiving the shaft54of the rear air mix door50. The aperture62further includes a T-shaped cross section (FIGS. 5 and 6) having an inner wall70with at least one chamfered step74. In an example embodiment, the inner wall70may include three chamfered steps74a,74b,74c(FIGS. 6, 7, 9, and 10) defining the T-shaped cross section. While three chamfered steps74a,74b, and74care illustrated, it is understood that any number of steps may be used to define the cross-sectional shape of the shaft54and align the shaft54in the aperture62. The chamfered steps74a,74b,74cmay be rotationally, or circularly, positioned within the inner wall70, such that the spaces within the aperture62not having the chamfered steps74a,74b,74cdefine the three points of the T-shape. In a plan view (also seen inFIG. 6), the steps74aand74bmay have a triangular shape (and more specifically a right triangular shape) with a curved hypotenuse, and the step74cmay have an elongate shape defined by a segment of the circular cross-sectional shape of the aperture62and with boundaries including the inner wall70and a chord of the circular cross-sectional shape of the aperture62.

Each of the chamfered steps74a,74b,74cincludes a sloped edge78that extends from the inner wall70of the aperture62to an inner edge80of the chamfered step74a,74b,74c. The sloped edge78may extend at a predetermined angle (for example only, 45°) relative to an insertion direction of the shaft54and may be a constant slope for each step74a,74b,74c.

The chamfered steps74a,74b,74calign the shaft54within the aperture62such that the rear air mix door50blocks the hot air flow path38. As illustrated inFIGS. 7 and 9, the chamfered steps may be sloped in different directions to assist rotation and alignment of the shaft54. For example, the step74ais sloped in a direction away from the cross-sectional cut and the step74bis sloped in a direction toward the cross-sectional cut. The different slopes assist the shaft54in turning clockwise within the aperture62.

The chamfered steps74aand74bdefine a space90for receiving a leg102aof the T-shaped shaft54. A width D2of the space90may be smaller than a diameter D1of the aperture62. For example only, the diameter D1of the aperture62may be approximately 10 millimeters (mm), while the width D2of the space90may be approximately 4 mm.

Referring now toFIGS. 8-10, the shaft54may be a male T-cut shaft that engages the female T-cut aperture62in the housing portion26(FIGS. 9 and 10). The shaft54may include a T-shaped cross-section having a first leg102a, a second leg102b, and a third leg102c, each having at least one chamfered step94that engages the at least one chamfered step74of the aperture62. While the shaft54is illustrated and described as having a T-shaped cross-section, it is understood that the shaft54could have any shaped cross-section (other than circular) that would lock movement of the shaft54relative to the aperture62. In an example embodiment, the shaft54may include chamfered steps94to engage the three chamfered steps74a,74b,74cin the aperture62. The chamfered steps94may extend around a circumference of the shaft54and may each include a sloped edge98. The sloped edge98may extend at a predetermined angle (for example only, at a 45° angle) to engage with the sloped edge78of the chamfered steps74a,74b,74cin the female T-cut aperture62.

When inserted, the leg102aof the shaft54engages with the chamfered steps74aand74bof the aperture62, the leg102bengages with the chamfered steps74aand74cof the aperture62, and the leg102cengages with the chamfered steps74band74cof the aperture62. The sloped edge78of the chamfered step74cengages with the sloped edge98of legs102band102cacross the top of the T-shaped shaft54.

The leg102aof the shaft54has a width d2that is smaller than a diameter d1of a base106of the shaft54. Further, the width d2and diameter d1may be similar to, and slightly less than the width D2and diameter D1, respectively. For example only, the diameter d1of the base106may be less than 0.1 mm smaller than the diameter D1, and more particularly may be within a range of 9.90 mm to 9.99 mm, while the width d2of the leg102amay be less than 0.1 mm smaller than the width D2, and more particularly may be within a range of 3.90 mm to 3.99 mm. Thus, the diameter d1may be sized such that the base106fits within the aperture62but not within the space90, and the width d2may be sized such that the leg102afits within both the aperture62and the space90.

As shown inFIGS. 9 and 10, the shaft54and aperture62engage such that the shaft54on the rear air mix door50slides into the aperture62. During assembly of the housing portion26, the shaft54is inserted into the aperture62. As the shaft54engages the chamfered steps74a,74b,74con the inner wall70of the aperture62, the shaft54twists, or rotates, rotating the rear air mix door50into the second position and blocking air flow from the hot air flow path38. The rotation path of the rear air mix door50is illustrated inFIG. 11. Once the leg102aaligns with the space90, the leg102areceived within, or is inserted into, the space90, locking the rear air mix door50into the second position. The automatic mechanical rotation of the shaft54(and rear air mix door50) as the shaft54is inserted into the aperture62removes risk or need for an assembler to position (rotate) the rear air mix door50within the aperture62manually to block air flow from the hot air flow path38and lock the rear air mix door50in place. Thus the aperture62forces the rear air mix door50to seal over the hot air flow path38without additional installation, saving time and cost and easing assembly.