Link mechanism

A link mechanism includes a first link member, a second link member, a third link member, and a link cover. The first link member is connected to a motor and rotated by the motor. The second link member is connected to an open/close door which opens and closes a blowout opening through which air is blown to adjust the temperature inside the passenger compartment. The third link member has a rotation shaft supported by a fixing member, and connects the first link member and the second link member with each other. The link cover is arranged to cover the periphery of the first link member. The link cover has a protrusion protruding toward the third link member.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/JP2017/020392 filed on Jun. 1, 2017. This application is based on and claims the benefits of priority from Japanese Patent Application No. 2016-128569 filed on Jun. 29, 2016. The entire disclosures of all of the above applications are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a link mechanism for opening and closing an opening and closing door provided in a blowout opening through which air is blown out for air-conditioning in a vehicle interior.

BACKGROUND ART

An air conditioner for a vehicle includes: plural air outlets for blowing out air to adjust the temperature inside the vehicle cabin from an air passage in an air conditioning case; plural open/close doors for opening and closing the air outlets; a link mechanism connected to the plural open/close doors; and a motor for opening and closing the open/close door via the link mechanism. Conventionally, this kind of link mechanism is described in Patent Document 1.

The link mechanism described in Patent Document 1 includes a mode link, a first link member, and a second link member. The mode link is formed in a disk shape. A guide groove is formed in the mode link. One end of the first link member has a pin to be inserted into the guide groove of the mode link. The other end portion of the first link member is connected to the rotation shaft of the open/close door via the second link member. The first link member has a rotation shaft rotatably supported with respect to the air conditioning case.

In the link mechanism described in Patent Document 1, when the mode link is rotated by the motor, the pin of the first link member is displaced along the guide groove of the mode link. When the first link member rotates around the rotation shaft based on the displacement of the pin, the second link member is displaced to open or close the defroster door.

PRIOR ART LITERATURES

Patent Literature

Patent Document 1: JP 2004-58941 A

SUMMARY OF INVENTION

In the link mechanism as described in Patent Document 1, the rotation shaft of the first link member is not fixed to the air-conditioning case, and is inserted into an insertion hole of the air-conditioning case so as to be prevented from falling out. Therefore, the orientation of the first link member may be affected by an external force applied from the open/close door to the first link member via the second link member.

Specifically, when the open/close door is held in a state of being opened with a predetermined opening degree, the open/close door receives the wind pressure from the flow of the air-conditioning air blown out from the air outlet. That is, the open/close door receives the wind pressure in a direction from the inside of the air conditioning case to the inside of the passenger compartment. In other words, the open/close door receives the wind pressure in the direction to bring the open/close door to the fully closed state. When an external force acts on the open/close door based on the wind pressure, the external force acts on the first link member via the second link member. When the orientation of the first link member is affected by the external force, the second link member is displaced from an appropriate position. As a result, the position of the open/close door is deviated in the direction to the fully closed position from the position with the predetermined opening. In this case, not only the air volume cannot be secured but also a wind noise may be caused because the opening degree of the open/close door becomes minute.

An object of the present disclosure is to provide a link mechanism capable of improving the positioning accuracy of an open/close door.

According to an aspect of the present disclosure, a link mechanism includes: a first link member that is to be connected to a motor, the first link member being rotated by the motor; a second link member that is to be connected to an open/close door to open and close an air outlet for blowing out air to adjust a temperature inside a passenger compartment; and a third link member having a rotation shaft that is to be supported by a fixing member, the third link member connecting the first link member and the second link member with each other. The first link member has a protrusion protruding toward the third link member.

According to another aspect of the present disclosure, a link mechanism includes a first link member, a second link member, a third link member, and a link cover. The first link member is to be connected to a motor, and the first link member is rotated by the motor. The second link member is to be connected to an open/close door to open and close an air outlet for blowing out air to adjust a temperature inside a passenger compartment. The third link member has a rotation shaft that is to be supported by a fixing member, and the third link member connects the first link member and the second link member with each other. The link cover is disposed to cover the periphery of the first link member, and the link cover has a protrusion protruding toward the third link member.

Accordingly, even when the orientation of the third link member is affected by an external force that is a wind pressure applied to the open/close door, the third link member contacts the protrusion of the first link member or the protrusion of the link cover, so that the inclination of the third link member can be suppressed. As a result, since the positional deviation of the second link member can be suppressed, the positioning accuracy of the open/close door can be improved.

DESCRIPTION OF EMBODIMENTS

A link mechanism according to an embodiment will be described below. First, an overview of an air conditioner for a vehicle will be described, in which a link mechanism of the present embodiment is used.

As shown inFIG. 1, an air conditioner10for a vehicle includes an air conditioning case20and an air conditioning unit30. The air conditioner10is provided inside the instrument panel of the vehicle.

An air passage21is formed inside the air conditioning case20. The air passage21is a passage for guiding air for air-conditioning in the passenger compartment. The air for air-conditioning is used for adjusting the temperature inside the passenger compartment. In the air passage21, air flows in the direction indicated by the arrow W in the drawing.

At a portion of the air conditioning case20on the upstream side in the air flow direction W, an outside air suction port22and an inside air suction port23are formed for taking air into the air passage21from the outside of the air conditioning case20. The outside air suction port22takes outside air that is air outside the vehicle compartment into the air passage21. The inside air suction port23takes inside air that is air inside the vehicle interior into the air passage21.

A defroster air outlet24, a face air outlet25, and a foot air outlet26are formed in a portion of the air conditioning case20on the downstream side in the air flow direction W. The defroster air outlet24blows the air flowing in the air conditioning case20toward the inner surface of the windshield of the vehicle. The face air outlet25blows the air flowing in the air conditioning case20toward the driver or passenger in the passenger seat. The foot air outlet26blows the air flowing in the air conditioning case20toward the feet of the driver or passenger in the passenger seat.

The air conditioning unit30generates air for air-conditioning based on the air introduced into the air passage21from the outside air suction port22or the inside air suction port23. The air conditioning unit30includes a blower fan31, an evaporator32, and a heater core33.

The blower fan31is disposed on the downstream side in the air flow direction W of the outside air suction port22and the inside air suction port23. The blower fan31is rotated by electric power to generate an air flow in the air passage21. The flow rate of the air flowing in the air passage21, in other words, the volume of the air for air-conditioning is adjusted by adjusting the amount of electricity supplied to the blower fan31.

The evaporator32is disposed on the downstream side in the air flow direction W of the blower fan31. The evaporator32is an element of a refrigeration cycle (not shown). In addition to the evaporator32, the refrigeration cycle includes a compressor, a condenser, and an expansion valve. In the refrigeration cycle, refrigerant is circulated in the order of the compressor, the condenser, the expansion valve, and the evaporator32. In the evaporator32, heat exchange is performed between the refrigerant flowing inside and the air in the air passage21, whereby the refrigerant evaporates and vaporizes. The evaporator32has a function of cooling air in the air passage21and a function of dehumidifying air in the air passage21by utilizing heat of vaporization when the refrigerant is vaporized.

The heater core33is disposed on the downstream side in the air flow direction W of the evaporator32. The heater core33is connected to an engine (not shown) via piping. Engine cooling water circulates between the engine and the heater core33via the piping. The heater core33heats air in the air passage21using the engine cooling water flowing inside as a heat source.

The air conditioning unit30further includes an inside/outside air switching door34, an air mixing door35, a defroster door36, a face door37, a foot door38, a link mechanism40, and a motor50.

The inside/outside air switching door34opens and closes the outside air suction port22and the inside air suction port23. When the inside/outside air switching door34is positioned at the inside air introduction position indicated by the solid line in the drawing, the outside air suction port22is closed and the inside air suction port23is opened. In this case, the air conditioner10enters an inside air circulation mode in which the inside air is taken into the air passage21from the inside air suction port23. On the other hand, when the inside/outside air switching door34is located at the outside air introduction position indicated by the broken line in the figure, the inside air suction port23is closed and the outside air suction port22is opened. In this case, the air conditioner10enters the outside air introduction mode in which outside air is taken into the air passage21from the outside air suction port22.

The air mixing door35adjusts the ratio between the volume of the air flowing into the heater core33and the volume of the air bypassing the heater core33. Specifically, the position of the air mixing door35can be adjusted between the maximum heating position indicated by the solid line in the figure and the maximum cooling position indicated by the broken line in the figure. When the position of the air mixing door35is the maximum heating position, most of the air having passed through the evaporator32passes through the heater core33, so that the temperature of the air rises most. When the position of the air mixing door35is the maximum cooling position, most of the air having passed through the evaporator32bypasses the heater core33. In this case, since the air cooled by the evaporator32directly flows to the respective outlets24to26, the temperature of the air decreases the most. In the air conditioner10, the opening degree of the air mixing door35is adjusted between the maximum heating position and the maximum cooling position, whereby the temperature of the air is adjusted.

The defroster door36rotates about a rotation shaft360to open and close the defroster air outlet24. The face door37rotates about a rotation shaft370to open and close the face air outlet25. The foot door38rotates about a rotation shaft380to open and close the foot air outlet26. Therefore, in the air conditioner10, the air conditioned in the air conditioning case20is blown toward the interior of the vehicle from the air outlets which are opened, of the air outlets24to26.

The link mechanism40is connected to the rotation shaft360of the defroster door36, the rotation shaft370of the face door37, and the rotation shaft380of the foot door38. The motor50rotates the rotation shaft360,370,380via the link mechanism40to open and close the doors36to38. The motor50is a servomotor.

Next, the structure of the link mechanism40will be described in detail. For the sake of convenience, only the structure for opening and closing the defroster door36will be described below, and the structure for opening and closing the face door37and the foot door38will be omitted. In the present embodiment, the defroster door36corresponds to an open/close door.

As shown inFIGS. 2 and 3, the link mechanism40includes a disk link member41, an intermediate link member42, a door link member43, and a link cover44.

The disk link member41has a disk shape around the axis m1in the drawing. A rotation shaft of the motor50shown inFIG. 3is connected to the center portion of the disk link member41. The disk link member41is rotated by the motor50in the direction indicated by the arrow R about the central axis m1shown inFIG. 2. As shown inFIG. 2, a guide groove411is formed on one side surface410of the disk link member41in the axial direction. The guide groove411is formed to extend in a curved shape in the circumferential direction of the disk link member41. In the present embodiment, the disk link member41corresponds to a first link member.

A fitting hole430is formed in the distal end portion of the door link member43. The rotation shaft360of the defroster door36shown inFIG. 1is fitted into the fitting hole430. The door link member43is connected to the defroster door36by the fitting structure, so that the door link member43rotates integrally with the defroster door36. As shown inFIG. 2, an elongated insertion hole431is formed in the base end portion of the door link member43. In the present embodiment, the door link member43corresponds to a second link member.

A pin420and a rotation shaft421are formed at one end portion of the intermediate link member42. As shown inFIG. 4, the pin420extends parallel to the axis m1toward the disk link member41, and is slidably inserted in the guide groove411of the disk link member41. The rotation shaft421has three claw portions421ato421c. The claw portions421ato421care attached to the air conditioning case20by being inserted into an insertion hole (not shown) formed in the air conditioning case20. Due to the attachment structure of the claw portions421ato421c, the intermediate link member42is supported by the air conditioning case20so as to be rotatable around an axis m2passing through the center of the rotation shaft421. In the present embodiment, the air conditioning case20corresponds to a fixing member.

A pin422is formed at the other end portion of the intermediate link member42. The pin422is inserted into the insertion hole431of the door link member43.FIG. 5is a cross-sectional view taken along a line IV-IV ofFIG. 2. Specifically, as shown inFIG. 5, the pin422is inserted in the insertion hole431of the door link member43with a predetermined clearance. In the present embodiment, the intermediate link member42corresponds to a third link member.

As shown inFIGS. 2 and 4, the link cover44is arranged so as to cover the periphery of the disk link member41. Plural protrusions440are formed on the outer peripheral surface of the link cover44. An insertion hole440ais formed in each of the protrusions440, and penetrates in a direction parallel to the axis m1. The link cover44is fastened to the air conditioning case20by bolts inserted in the insertion holes440a, whereby the link cover44is fixed to the air conditioning case20.

As shown inFIG. 4, a portion of the link cover44opposing the intermediate link member42has a protrusion45protruding toward the intermediate link member42. As shown inFIG. 5, the opposing surface441aof the protrusion45opposing the intermediate link member42is formed parallel with the opposing surface423of the intermediate link member42opposing the disk link member41.

FIG. 6is a cross-sectional view taken along a line VI-VI ofFIG. 2. As shown inFIG. 6, the side wall441b,441cof the protrusion45in the rotational direction R of the disk link member41has a tapered shape.

Next, an operation example of the link mechanism40of the present embodiment will be described.

When the disk link member41is rotated by the motor50around the axis m1, the pin420of the intermediate link member42is displaced along the guide groove411of the disk link member41. Due to the displacement of the pin420, the intermediate link member42rotates about the rotation shaft421, whereby the door link member43is displaced. At this time, the door link member43and the rotation shaft360of the defroster door36integrally rotate, whereby the defroster door36opens and closes.

For example, when a heat mode is selected as the operation mode of the air conditioner10, as shown inFIG. 1, the defroster door36is held at the position P2where the defroster door36is opened by the predetermined opening degree from the fully closed position P1. The predetermined opening position P2is set, for example, at a position to have an angle 5° from the fully closed position P1. In this case, a wind pressure acts on the defroster door36due to the flow of air passing through the defroster air outlet24from the air passage21, whereby an external force is applied to the defroster door36in the direction toward the fully closed position P1. This external force will displace the door link member43in the direction indicated by the arrow A shown inFIG. 2, so that an external force in the direction A is applied to the end portion of the intermediate link member42adjacent to the pin422.

Meanwhile, since the disk link member41is connected to the rotation shaft of the motor50, the position of the disk link member41is fixed. Since the pin420of the intermediate link member42is inserted into the guide groove411of the disk link member41, the position of the end portion of the intermediate link member42adjacent to the pin420is fixed.

Thus, as shown inFIG. 7, when an external force is applied to the end portion of the intermediate link member42adjacent to the pin422in the direction A, as shown by a double chain line inFIG. 7, the intermediate link member42is inclined in such a manner that the end portion adjacent to the pin422is lifted up toward the door link member43. Since the door link member43is displaced by the inclination of the intermediate link member42, the position of the defroster door36may be shifted from the regular position P2.

In this respect, according to the link mechanism40of the present embodiment, as shown inFIG. 5, when the intermediate link member42is inclined, the intermediate link member42comes into contact with the protrusion45of the link cover44. Therefore, the inclination of the intermediate link member42can be suppressed as shown by the double chain line inFIG. 5, according to the link mechanism40of the present embodiment, compared with a structure in which the protrusion45is not formed on the link cover44, as shown by the double chain line inFIG. 7, in which the intermediate link member42is greatly inclined.

According to the link mechanism40of the present embodiment described above, the functions and effects shown in the following (1) to (3) can be obtained.

(1) Since the inclination of the intermediate link member42is suppressed, it is possible to suppress the positional deviation of the door link member43. Accordingly, it is easy to position the defroster door36at the position P2with the predetermined opening degree. That is, the positioning accuracy of the defroster door36can be improved.

(2) The side wall441b,441cof the protrusion45in the rotational direction R of the disk link member41is formed in the tapered shape. As a result, in case where the intermediate link member42moves relative to the disk link member41in the rotational direction R, even if the intermediate link member42contacts the side wall441b,441cof the protrusion45, the impact force generated to the intermediate link member42can be reduced. Therefore, it is possible to suppress abnormal noise generated by the contact and breakage of the intermediate link member42.

(3) The opposing surface441aof the protrusion45that faces the intermediate link member42is formed in parallel with the opposing surface423of the intermediate link member42that faces the disk link member41. Accordingly, when the intermediate link member42comes into contact with the protrusion45, the inclination of the intermediate link member42can be suppressed more accurately, so that the positioning accuracy of the defroster door36can be further improved.

It should be noted that the above embodiment may be modified as follows.

The shape of the protrusion45can be appropriately changed. For example, the tip portion of the protrusion45may be formed in a curved shape.

The protrusion45may be formed at least in a portion of the link cover44opposing the intermediate link member42when the defroster door36is held at the position P2with the predetermined opening degree. Thus, it is possible to improve the positioning accuracy when the defroster door36is held at the position P2.

As shown inFIG. 8, the protrusion45is not limited to be formed on the link cover44, and may be formed on an outer edge portion of the side surface410of the disk link member41. In this case, the protrusion45may be formed at least in a portion of the disc link member41opposing the intermediate link member42when the defroster door36is held at the position P2with the predetermined opening degree. Thus, it is possible to improve the positioning accuracy when the defroster door36is held at the position P2.

The intermediate link member42is not limited to be fixed to the air conditioning case20and may be supported by an arbitrary fixing member.

The respective shape of the disk link member41, the intermediate link member42, and the door link member43can be appropriately changed.

The structure of the protrusion45of the above embodiment may be used as a structure for suppressing the inclination of the intermediate link member used for opening and closing the face door or the foot door.

The present disclosure is not limited to the specific examples. Those skilled in the art appropriately design modifications to these specific examples, which are also included in the scope of the present disclosure as long as they have the features of the present disclosure. The elements, the arrangement, the conditions, the shape, etc. of the specific examples described above are not limited to those exemplified and can be appropriately modified. The combinations of elements included in each of the above described specific examples can be appropriately modified as long as no technical inconsistency occurs.