Air flap opening and closing mechanism of a vehicle air conditioning device

Abstract

An air damper opening and closing mechanism (21) of a vehicle air conditioning device (11), comprising: a connecting plate (22) which is designed such that a central portion is rotatably mounted and is provided with a cam groove (24) along an outer peripheral portion, and the connecting plate (22) is drivable for rotation by a stepping motor (30), an air damper lever (26) comprising a pin (28) which is slidably inserted into the cam groove (24) and which is designed to rotate by movement of the pin (28) over the cam groove (24), and an air damper (19) comprising an air damper shaft (20) coupled to the air damper lever (26) and configured to open and close by rotation of the air damper shaft (20), wherein an end portion of the cam groove (24) for a reference positioning of the stepping motor (30) has a shape such that a curved surface that does not contact the outer circumference of the pin (28) is a connection between points A and B, wherein point A is a contact point of the outer circumference of the pin (28) with an end surface of the cam groove (24) and point B is a contact point of the outer circumference of the pin (28) with a side wall surface (24A) of the cam groove (24) when the air damper (19) is in a closed state, and wherein the end portion of the cam groove (24) has a shape such that a curved surface having a radius of curvature r smaller than a radius of curvature R of the pin (28) forms a connection between a plane containing the end surface of the cam groove (24) passing through point A and an extension plane of the side wall surface (24A) of the cam groove (24) passing through point B.

Description

[0001] The present invention relates to an air louver opening and closing mechanism of a vehicle air conditioning device, the air louver opening and closing mechanism comprising a connecting plate provided with cam grooves and configured to rotate the connecting plate by a stepping motor to open and close an air louver.

[0002] A heating, ventilation, and air conditioning (HVAC) unit is configured as a unit constituting a vehicle air conditioning device to selectively blow air into a vehicle compartment through a face blowout port, a foot blowout port, and / or a differential blowout port to adjust the temperature of the interior of the vehicle compartment, wherein the air temperature is adjusted to a set temperature by an evaporator, a heater core, an air mix door, etc. arranged inside the unit.

[0003] In addition to the air mix damper, a plurality of blow-mode switching dampers configured to open and close each blow port, such as a face / differential damper and a foot damper, are rotatably supported by corresponding damper shafts in the HVAC unit. These dampers are opened and closed by a linkage mechanism including, for example, a link plate rotated by a motor actuator including a potentiometer or a stepping motor, and a damper lever having a pin slidably inserted into a cam groove provided on the link plate. In this way, temperature adjustment control or blow-mode switching is performed (see, for example, JP 4 168 583 B2 and JP H05-25 291 Y2).

[0004] In a louver opening and closing mechanism configured to open and close each louver through the linkage mechanism including the connecting plate with the cam groove, the louver lever, etc., as described above, the pin provided on the louver lever, which has a round cross section, is slidably inserted into the cam groove of the connecting plate. Therefore, the cam groove has a groove width such that the pin is inserted with a certain clearance, and an end portion of the cam groove generally has an arc shape with a radius of 1 / 2 the groove width, as described in JP 4 168 583 B2 and JP H05-25 291 Y2.

[0005] US 2015 / 0 017 903 A1 discloses a flap driving force transmission mechanism for a vehicle air conditioner, which has a connecting plate with a cam groove in which a pin of an air flap lever is slidably inserted so that an air flap connected to the air flap lever can be moved by rotating the connecting plate, wherein an end portion of the cam groove is square.

[0006] JP S63-179 214 U discloses a flap movement mechanism with a connecting plate with a cam groove and a pin guided therein, wherein the cam groove has two lateral projections at each of its groove ends so that the pin can rest against these without resting against a respective groove end.

[0007] In the louver opening and closing mechanism configured to rotate the connecting plate provided with the cam groove as described above by the stepping motor, reference positioning (initialization) of the stepping motor must be performed. Such initialization is usually performed in such a manner that the connecting plate is rotated so that the pin of the louver lever is positioned at an end portion of the cam groove and the louver is in a closed state to press the louver against a sealing surface. However, depending on the direction of the louver lever, the louver lever may rotate in an opening direction of the louver during initialization, resulting in unstable initialization.

[0008] That is, if, as in Fig. 4A and Fig. 4B illustrates the state of Fig. 4A, that is, a state in which a connecting plate 1 is rotated in a direction N to bring a pin 4 of a damper lever 3 into contact with an end portion of a cam groove 2, and an air damper 5 is rotated about a damper axis 6 to contact a sealing surface 7, is established at initialization when the direction of the pin 4 of the damper lever 3 is in the load direction of the pin 4, a torque in the opening direction of the damper 5 is applied to the damper lever 3. Therefore, as shown in Fig. As illustrated in Fig. 4B, the pin 4 of the louver lever 3 returns along an arc surface of the end portion of the cam groove 2 through a gap, thereby opening the louver 5. Therefore, the initialization may be unstable.

[0009] The present invention was made in view of the above-described situation. The present invention is intended to provide an air louver opening and closing mechanism of a vehicle air conditioning device configured to open and close an air louver by a louver lever provided with a pin slidably fitted into a cam groove of a connecting plate rotated by a stepping motor. The air louver opening and closing mechanism is configured so that the stepping motor can be stably initialized regardless of the direction of the louver lever.

[0010] In order to solve the above-described problem, the louver opening and closing mechanism of the vehicle air conditioning device of the present invention comprises the features of claim 1.

[0011] According to the invention, an end portion of the cam groove is in such a shape that the curved surface having the radius of curvature r smaller than the radius of curvature R of the pin forms a connection between the plane passing through the point A and the extension plane of the side wall surface of the cam groove passing through the point B. Therefore, when the connecting plate is rotated so that the pin of the louver lever is positioned at an end portion of the cam groove and that the louver is in the closed state with the outer peripheral surface of the pin contacting the point A of an end surface of the cam groove and the point B of the side wall surface of the cam groove, the pin can be securely received at an end portion of the cam groove without any pin movement gaps.Therefore, even if the torque in the rotational direction is applied to the louver lever, the pin at an end portion of the cam groove does not move, and initialization of the stepping motor can be stably performed with the louver kept in the closed state regardless of the direction of the louver lever.

[0012] When reference positioning (initialization) of the stepping motor is performed in a state where the link plate is rotated so that the pin of the louver lever is positioned at one end portion of the cam groove and that the louver is in the closed state, the torque can be applied in the rotational direction of the louver lever depending on the direction of the louver lever. However, one end portion of the cam groove is in the shape described above. Therefore, when the pin of the louver lever is positioned at one end portion of the cam groove and the louver is in the closed state, the outer periphery of the pin is received in contact with points A and B. Consequently, there is no gap between the pin and the cam groove, and the louver lever is rotatable within such a gap.Initialization can be performed without rotating the louver lever in the direction of opening the louver in the state where the louver is held in the closed position. Therefore, opening of the louver by rotating the louver lever is prevented due to the pin returning to the arc surface through the gap between the cam groove and the pin, and thus stable initialization can be performed. This can improve the quality and reliability of the vehicle air conditioning system. Fig. 1 is a perspective view of a vehicle air conditioning apparatus of an embodiment of the present invention. Fig. 2 is a partial side view of a louver opening and closing mechanism configured to open and close a louver. Fig. 3 is a view for describing a configuration of an end portion shape of a cam groove provided on a connecting plate of the louver opening and closing mechanism. Fig. 4A is a view for describing a configuration of an end portion shape of a cam groove of a typical example for better understanding of the invention, which is Fig. 3 corresponds. Fig. Fig. 4B is a view for describing an operation of the cam groove of the typical example used to Fig. 3 corresponds to an initialization.

[0013] An embodiment of the present invention is described below with reference to Fig. 1 to 4 are described.

[0014] Fig. 1 illustrates a perspective view of a vehicle air conditioning device of an embodiment of the present invention, Fig. 2 illustrates a side view of a louver opening and closing mechanism configured to open and close a louver, and Fig. 3 illustrates a view for describing a configuration of an end portion shape of a cam groove provided on a connecting plate of the louver opening and closing mechanism.

[0015] A vehicle air conditioning device 11 of the present embodiment includes a heating, ventilation, and air conditioning (HVAC) unit 12 and a blowing unit 13 integrally provided on one side of the HVAC unit 12.

[0016] The blowing unit 13 includes a built-in blower and a built-in motor for supplying interior vehicle compartment air (also simply referred to as "internal air") under pressure or external air introduced through an internal / external air switching device 14 to the HVAC unit. A part of a blower housing and a part of a unit casing 15 on an HVAC unit side are generally used, and thereby the blowing unit 13 is continuous with the HVAC unit 12. Note that the internal / external air switching device 14 is provided with an internal / external air switching damper between an internal air intake port and an external air intake port. Such a blowing unit 13 is known.

[0017] The HVAC unit 12 includes the unit casing 15, which is composed of a group of several separate casings. An evaporator, a heater core, an air mix damper, etc., arranged in an air flow path in the HVAC unit 12, adjusts the temperature of air supplied from the blowing unit 13 to a set or predetermined temperature. Such adjusted-temperature air is blown into a vehicle compartment through a differential blowing port 16, a face blowing port 17, and a foot blowing port 18 opening downward from the air flow path. In this way, the temperature of the interior of the vehicle compartment is adjusted. Such a configuration and function are known.

[0018] Three louvers, including a face louver, a foot louver, and a differential louver, are provided separately for the differential discharge port 16, the face louver 17, and the foot louver 18. Alternatively, two louvers are provided, including a single face / differential louver used jointly as a face louver and a differential louver, and a single foot louver. Each of the discharge ports 16, 17, and 18 is opened and closed by these louvers, and therefore, a set temperature air discharge mode is selectively switchable to a face discharge mode, a foot discharge mode, a differential discharge mode, a differential / face discharge mode, a bi-level discharge mode, etc. Such a configuration is also known.

[0019] The blow-out mode switching louver of the present embodiment includes two louvers, namely, a foot louver 19 and a face / differential louver (not shown). The foot louver 19 is rotatably supported by a louver shaft 20 in the unit case 15. Similarly, the face / differential louver is rotatably supported by a louver shaft (not shown) in the unit case 15. Each louver is opened and closed by a louver opening and closing mechanism 21 disposed on a side surface of the unit case 15.

[0020] The louver opening and closing mechanism 21 includes a connecting plate 22 configured such that a center portion thereof is rotatably supported on the side surface of the unit case 15 by an axle portion 23 and provided with two independent cam grooves 24, 25 at outer peripheral portions; louver levers 26, 27 each fixed at one end side to an axle end of the louver axle 20 of the foot louver 19 and an axle end of the louver axle of the face / differential louver and each slidably inserted at the other end side into the cam grooves 24, 25 by pins 28, 29 having a round cross section; and a stepping motor 30 fixed to an outer surface side of the connecting plate 22 for driving the connecting plate 22 around the axle portion 23 for rotation.

[0021] In such a louver opening and closing mechanism 21, reference positioning (initialization) of the stepping motor 30 must be performed at the time of initial connection to a power source or at the time of maintenance for the purpose of rotating the foot louver 19 and the face / differential louver to each blowout mode switching position by the louver opening and closing mechanism 21. As described above, such initialization is performed as follows: The connecting plate 22 is rotated so that the pin 28 of the louver lever 26 is positioned at one end portion of the cam groove 24 and that the foot louver 19 is in a closed state to press the foot louver 19 against, for example, a sealing surface 31.In a case where the direction of the louver lever 26 faces the load direction on the pin 28, the louver lever 26 may rotate in the opening direction of the foot louver 19 at initialization, resulting in unstable initialization.

[0022] In the present embodiment, the shape of an end portion of the cam groove 24 is as shown in Fig. 3, designed to perform initialization stably, even in the case described above.

[0023] For slidably inserting the pin 28, the cam groove 24 has a groove width that is wider than the outer diameter of the pin 28 by predetermined dimensions. The pin 28 is inserted into the cam groove 24 with a certain clearance. An outer peripheral surface of the pin 28, which has a radius of curvature R with respect to the cam groove 24, contacts an end surface of the cam groove at a point A when the connecting plate 22 rotates to rotate the foot damper 19 to a closed position in contact with the sealing surface 31.

[0024] Meanwhile, when the connecting plate 22 is rotated to rotate the louver lever 26 by the pin 28 slidably fitted in the cam groove 24, the outer peripheral surface of the pin 28 contacts a side wall surface of the cam groove 24 on the side that pushes the pin 28, that is, a side wall surface to A in this case. Assuming that a contact point when the foot louver 19 is rotated to the closed position in which the sealing surface 31 is contacted is B, a connecting surface 32 between the points A and B of an end surface of the cam groove 24 is in such a shape that it is connected by a curved surface that does not contact the outer peripheral surface of the pin 28 having the radius of curvature R according to the invention.

[0025] Specifically, the connecting surface 32 between points A and B of an end surface of the cam groove 24 is in such a shape that a plane passing through the above-described point A and an extension plane of the side wall surface 24A of the cam groove 24 passing through the above-described point B are connected by a curved surface having a radius of curvature r smaller than the radius of curvature R of the pin. When the foot damper 19 is rotated to the closed position, the outer periphery of the pin 28 of the damper lever 26 is securely received in contact with points A and B, and therefore, opening of the foot damper by returning the pin 28 along an arc surface of a groove end is prevented.

[0026] According to the present embodiment, the above-described configuration provides the following features and advantageous effects.

[0027] In the above-described louver opening and closing mechanism 21, the stepper motor 30 is driven by a controller to rotate the connecting plate 22 to the set position. Thus, the foot louver and the face / differential louvers are each rotated to the selected blowout mode positions. Consequently, the air at the set temperature can be blown into the vehicle compartment through the differential blowout port 16, the face blowout port 17, and / or the foot blowout port 18.

[0028] That is, the cam grooves 24, 25 are rotated by rotating the connecting plate 22, and the pins 28, 29, which are respectively inserted into the cam grooves 24, 25, are slid along the shapes of the cam grooves 24, 25. In this way, the louver levers 26, 27 rotate around the louver axis 20 (the louver axis of the face / differential louver is not shown), and the foot louver 19 and the face / differential louver rotate to the set positions. With this configuration, the blowing mode is set to the face blowing mode, the foot blowing mode, the differential blowing mode, the differential / face blowing mode, and the bi-level blowing mode as described above, and then the air at the set temperature is blown into the vehicle compartment.

[0029] Meanwhile, the air damper opening and closing mechanism 21 is operated as described above, and therefore the stepping motor 30 must be initialized. Such initialization is performed upon initial connection of the stepping motor 30 to the power supply or during maintenance. In this case, reference positioning (initialization) is performed in such a way that a single air damper, in this case, the foot air damper 19, is brought into the closed state. At this point, the pin 28 of the air damper lever 26 is at an end portion of the cam groove 24, as shown in Fig. 3, and the foot air flap 19 contacts the sealing surface 31. In this way, the closed state is achieved.

[0030] Then, when the foot damper 19 is brought into the closed state as described above, the pin 28 of the damper lever 26 contacts an end portion of the cam groove 24 at points A and B, and the connecting surface 32 between points A and B has such a surface configuration that the connecting surface 32 does not contact the outer peripheral surface of the pin 28 having the radius of curvature R. Therefore, the pin 28 is securely received at an end portion of the cam groove 24.

[0031] The outer periphery of the pin 28 is securely received in contact with the points A and B of the end portion of the cam groove 24 without any gaps. Therefore, when the connecting plate 22 rotates the louver in a closing direction in such a state and a torque in the opening direction of the foot louver 19 is applied to the louver lever 26, even if the direction of the louver lever 26 is the load direction on the pin 28, as shown in Fig. 4(B), when the pin 28 returns along the arc surface of the end portion of the cam groove 24 through a gap due to the torque in the air damper opening direction, the foot air damper 19 is not forced to open, and thereby the stepping motor 30 can be initialized with the foot air damper 19 maintained in a closed state.

[0032] With this configuration, the opening of the foot damper 19 due to rotation of the damper lever 26 is not caused when the pin 28 of the damper lever 26 returns to the arc surface at the gap between the cam groove 24 and the pin 28. Therefore, the stepping motor 30 can be stably initialized, and the quality and reliability of the vehicle air conditioning device 11 can be improved.

[0033] In addition, an end portion of the cam groove 24, by the curved surface having the radius of curvature r smaller than the radius of curvature R of the pin 28, forms the connecting surface 32 between the plane passing through the point A and the extension plane of the side wall surface 24A of the cam groove 24 passing through the point B. Therefore, when the connecting plate 22 is rotated to position the pin 28 of the louver lever 26 at an end portion of the cam groove 24 and bring the foot louver 19 into the closed state, the outer peripheral surface of the pin 28 contacts the point A of an end surface of the cam groove 24 and the point B of the side wall surface 24A of the cam groove 24, and thereby the pin 28 can be securely received at an end portion of the cam groove 24 without any movement gaps.

[0034] Therefore, even if a torque in a rotational direction is applied to the louver lever 26, the stepping motor 30 can be stably initialized in a state in which the foot louver 19 is held in the closed state without movement of the pin 28 at an end portion of the cam groove 24 regardless of the direction of the louver lever 26.

[0035] It should be noted that the present invention is not limited to the aspect of the above-described embodiment, and modifications can optionally be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the example where the present invention is applied to a louver opening and closing mechanism 21 including the foot louver 19 and configured to open and close the blow-out mode switching louver has been described. However, the present invention is not limited to the blow-out mode switching louver, and needless to say, it can be similarly applied to other louver opening and closing mechanisms such as a temperature-adjusting air mixing louver and an internal / external air switching louver.

[0036] Furthermore, the connecting plate 22 provided with the two cam grooves 24, 25 at the outer peripheral portions has been described. Needless to say, the number of cam grooves increases or decreases in correspondence with the number of opening and closing louvers. Therefore, the outer shape can be changed into a variety of shapes according to a cam groove combination. Furthermore, in the above-described embodiment, the example where the stepping motor 30 is initialized using the foot louver 19 was described, but needless to say, it can be initialized using other louvers. Description of reference symbols: 11 Vehicle air conditioning device 19 Foot air flap (air flap) 20 Air flap axis 21 Air flap opening and closing mechanism 22 Connecting plate 24.25 Curve groove 24A Sidewall surface of a curve groove 26,27 Air flap lever 28.29 pen 30 stepper motor 32 connection surface

Claims

[1] An air damper opening and closing mechanism (21) of a vehicle air conditioning device (11), comprising: a connecting plate (22) which is designed such that a central portion is rotatably mounted and is provided with a cam groove (24) along an outer peripheral portion, and the connecting plate (22) is drivable for rotation by a stepping motor (30), an air damper lever (26) comprising a pin (28) which is slidably inserted into the cam groove (24) and which is designed to rotate by movement of the pin (28) over the cam groove (24), and an air damper (19) comprising an air damper shaft (20) coupled to the air damper lever (26) and configured to open and close by rotation of the air damper shaft (20), wherein an end portion of the cam groove (24) for a reference positioning of the stepping motor (30) has a shape such that a curved surface that does not contact the outer circumference of the pin (28) is a connection between points A and B, wherein point A is a contact point of the outer circumference of the pin (28) with an end surface of the cam groove (24) and point B is a contact point of the outer circumference of the pin (28) with a side wall surface (24A) of the cam groove (24) when the air damper (19) is in a closed state, and wherein the end portion of the cam groove (24) has a shape such that a curved surface having a radius of curvature r smaller than a radius of curvature R of the pin (28) forms a connection between a plane containing the end surface of the cam groove (24) passing through point A and an extension plane of the side wall surface (24A) of the cam groove (24) passing through point B.

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