JPH0792079B2 - Automotive air conditioner - Google Patents

Description

Description: [Industrial application] The present invention relates to a blower for an air conditioner for a vehicle.

[Prior Art] Each of the heating and cooling heat exchangers arranged in the air conditioning duct has considerably large ventilation resistance. Therefore, how much of the conditioned air introduced from the air intake port into the duct should be used. The ventilation resistance value for the air passing through the duct varies considerably depending on whether the air is passed through the heat exchanger.

In a typical device, when the capacity changeover switch of the blower with variable blower capacity is set to the "high" position, 40 mmAq, heating heat the heater and defrost blowing air conditioning mode to pass exchangers are 55mmAq out, each air volume of the air-conditioning mode 450 m ³ / h and 350 meters ³
Values such as inside / outside of / h have been measured.

[Problems to be Solved by the Invention] Since the resistance coefficient of the duct as a ratio of the loss of the air head due to passing through the air conditioning duct is directly proportional to the blower total pressure and inversely proportional to the square of the air volume, This characteristic value varies depending on the operating state of the air conditioner. The fan efficiency of the blower is directly proportional to the product of the blower total pressure and the air volume, and is inversely proportional to the fan air volume. Therefore, in the conventional air conditioner, it is not possible to exert the maximum fan efficiency both in the heater or defrost air conditioning mode with high ventilation resistance and also in the ventilation air conditioning mode with relatively low ventilation resistance. The fan efficiency in air conditioning mode had to be reduced.

An object of the present invention is to provide an automobile air conditioner including a blower capable of keeping fan efficiency at the highest level possible under any of ventilation, heater, and defrosting air conditioning modes. To do.

[Means for Solving the Problems] In order to achieve the above object, an automobile air conditioner according to the present invention incorporates a centrifugal blower having a scroll casing, a first vent for ventilation, and a heat. A second air outlet for air conditioning and a third air outlet for defrosting are selectively opened and closed, the air conditioner for an automobile including an air conditioning mode switching means for switching an air conditioning mode, and is arranged in the scroll casing. The first
An air passage that widens the divergence angle of the air passage for the centrifugal blower when the air outlet is opened, and reduces the divergence angle of the air passage when the second air outlet is opened and the third air outlet is opened. A configuration including a divergence angle increasing / decreasing unit and an interlocking unit for operating the airway divergence angle increasing / decreasing unit in association with the operation of the air conditioning mode switching unit is adopted.

[Operation and Effect of the Invention] In the vehicle air conditioner according to the present invention having the above-described configuration, the air duct expansion in the scroll casing of the blower is performed by operating the air duct switching damper that constitutes the air conditioning mode switching means. The angle increasing / decreasing means works in conjunction with each other to increase the divergence angle of the air passage in the ventilation air-conditioning mode and decrease the divergence angle of the air passage in the heat / defrost air-conditioning mode. This automatically moves the blower operating point so that the fan efficiency is maximized under any air conditioning mode.

Since fan efficiency is the ratio of effectively extracted wind power to the input to the fan rotation axis, maintaining this ratio at a high level under any air conditioning mode means that part of the input is due to blast noise, etc. This means that the degree of airflow is lost as a result, or the degree of reduction in air volume due to airflow resistance is suppressed to a low degree, which improves the airflow capacity of the vehicle air conditioner and reduces airflow noise.

[Embodiment] The configuration of an automobile air conditioner according to the present invention will be specifically described below based on an embodiment shown in the drawings.

1 to 5 show one embodiment of the device, and the entire device has a discharge port 1b of a centrifugal blower A and an air conditioning duct B as shown in FIG. 3 as a schematic side sectional view thereof. Is connected to the air inlet end 20a.

The blower A accommodates a centrifugal multi-layer fan 2 driven by a fan motor 12 in a fan casing 1 having a scroll shape, and has an outside air intake port 21 or a side wall opening at the top of an inside / outside air switching box 20 assembled to an intake port 1a. The outside air or the air in the vehicle compartment is sucked through either of the first and second inside air suction ports 22 and 23 provided so as to face each other. Reference numerals 24 and 25 are first and second inside / outside air switching dampers which are interlocked with each other via a link mechanism (not shown) to selectively introduce inside air or outside air.

The fan casing 1 is made of hard synthetic resin or metal and has a scroll shape. The upper casing 1A and the lower casing 1B, which are divided by a dividing line provided on the peripheral wall, are combined by a fastening metal fitting 26. There is. Then, the divergence angle as the air divergence angle increasing / decreasing means is in contact with the peripheral wall surface in the downstream area of the air flue in the casing 1 having the air flue a for discharging the compressed air which is spirally widened toward the end. The adjusting plate 3 is incorporated.

The spread angle adjusting plate 3 is made of a metal plate or a synthetic resin plate having a high elasticity, and the upper and lower ends of the rotary shaft 4 attached to one side edge of the rectangular plate are connected to the fan casing 1. By being fitted in the shaft holes respectively provided on the top wall surface and the bottom wall surface, it can be rotated around the rotation shaft 4.

Further, when the divergence angle adjusting plate 3 occupies the position where the divergence angle of the air duct is widest on the peripheral wall surface of the fan casing 1 on the downstream side of the air duct, the plate surface of the plate 3 is the casing 1.
A bulging portion 1c is formed so as to coincide with the inner wall surface of the so as not to obstruct the air passage. And casing 1
A stopper 6 as an arc-shaped protrusion having a height of 2 to 3 mm or less is provided integrally with the casing 1 on the bottom surface of the plate 3 for defining the position where the plate 3 most sandwiches the air passage divergence angle. .

A plate reinforcing rod 7 is attached to the other side edge of the spread angle adjusting plate 3, and a rotating force for rotating the plate 3 around its rotation axis 4 is attached to the rod 7. The torque transmission member 8 that transmits the torque is connected. In this embodiment, the member 8 is in the shape of a small plate, and the upper end of the rod 7 is loosely fitted in the shaft hole 8a formed at one end of the member 8 and a part of the air conditioning mode switching means is provided at the other end. The wire 9 for remote rotation of the plate 3 having one end thereof connected to the air conditioning mode switching lever 45 provided on the operation panel 50 of the air conditioner is connected as an interlocking device. Reference numeral 10 is a cover tube for holding the wire 9.

The curvature of the divergence angle adjusting plate 3 is made to match the curvature of the casing wall surface at this portion in the state of being accommodated in the bulging portion 1c of the fan casing 1. When the wire 9 is pushed out by the movement of the air-conditioning mode switching lever 45 in order to hold the spread angle of the scroll-shaped air passage a, the plate 3 is rotated by the arcuate stopper 6 to a position where its advance is blocked, Since the stopper 6 has an arcuate shape having a narrower curvature due to the elasticity of the plate, both side walls of the narrowed air passage are smoothly and continuously scrolled. The arcuate stopper 6 is also symmetrically provided on the inner wall surface of the top of the fan casing 1.

The operation panel 50 for the air conditioner is generally incorporated in the driver's seat instrument panel, and in addition to the air conditioning mode switching knob 51, the vehicle interior temperature adjusting lever knob 52, the inside / outside air switching lever knob 53, and the blower motor. A knob 54 for the 12 rotation speed switching lever is provided.

The lever 45 that rotates around the rotary shaft 45a by operating the air-conditioning mode switching knob 51 has the damper groups 39 to 41 for selectively opening and closing the ventilation, heat, and defrost outlets 36 to 38 in advance. Another remote operation wire 15 for transmitting the above operation force to a link mechanism (not shown) for interlocking under the defined interlocking relationship.
Are connected. 16 is a tube as a support cover for this wire. However, the wire 15 may be branched from the middle of the wire 9 instead of being directly attached to the lever 45.

Here, the divergence angle of the air passage a in the fan casing 1 having the scroll shape of the centrifugal blower A will be described with reference to FIG. Centrifugal force is generated in the blades of the fan 2 that start a circumferential motion at high speed with the start of the fan motor 12, and the air to be conditioned that is sucked into the inner space of the fan from the suction port 1a is indicated by an arrow (f) in the figure. With a direction such as
Blow out under pressure.

Now, a virtual extension line (e) is drawn on the upstream side end of the inner peripheral wall surface of the casing 1, and a point intersecting with the outer peripheral surface of the fan 2 is defined as (a). The intersection of the extension line of the radius of the fan 2 and the wall surface of the fan casing 1 at the position of the rotation angle θ ° (b), the intersection with the spread angle adjusting plate 3 (c), and the outer periphery of the fan 2 as well. Let the intersection with the face be (d).

When the plate 3 is brought into contact with the inner wall surface of the fan casing 1 to maximize the divergence angle of the air passage a, the air passage divergence angle α at the rotation angle θ ° is the point (b) and the point (d). It is expressed as the crossing angle of the tangent to the curved surface. Also, when the plate 3 is brought into contact with the stopper 6 to minimize the spread angle, the wind path spread angle β at the same rotation angle θ ° position.
Is represented as the intersection angle of the respective tangents to the curved surface at point (c) and point (d).

In the device of this embodiment, in the ventilation air-conditioning mode in which the ventilation resistance is relatively small, the value of the air duct spread angle α that can cause the fan A to have the maximum fan efficiency is 7 °, and the ventilation resistance is relatively large. In the extremely large heat and defrost air conditioning mode, the value of the air duct divergence angle β at which the maximum fan efficiency was generated was 5 °.

The air conditioning duct B is, as shown in FIG. 3, inside the duct main body 20 made of hard synthetic resin or the like, an evaporator 31 as a heat exchanger for cooling, a hot water heat exchanger for heating in order from the upstream side. A heater core 32, a bypass cool air passage 33 for the heater core, a bypass passage damper 34, and an air mix chamber 35 for mixing cold and warm air are provided.

A ventilation outlet is provided at the air outlet end of the duct body 20.
36, a heat outlet 37, and a defrost outlet 38 are provided, and each outlet communicates with each outlet grill 36a, 37a, and 38a that opens toward the vehicle interior through an extension duct for each outlet. Has been done. 39, 40, and 41 are outlets 36
A group of air-conditioning mode switching dampers, which together with the device operation panel 50, constitute an air-conditioning mode switching means for selectively opening and closing ~ 38 to change the air conditioning state in the vehicle compartment, and are not shown. It is placed in a specific interlocking relationship via the link mechanism. This link mechanism is rotated by operating the knob 51 of the above-mentioned air conditioning mode switching lever incorporated in the driver's seat instrument panel surface or the like.

Next, the operation of the apparatus of the above embodiment will be described. First, a fan characteristic graph (see FIG. 7) showing the blowing characteristics of the blower will be described. Now, letting Va be the outlet air volume of the blower, Δp the blower total pressure, N the fan speed, T the fan drive torque, u ₂ the peripheral speed of the fan, and D ₂ the outer diameter of the fan, the flow coefficient φ , Pressure coefficient 4, fan efficiency ηf, and resistance coefficient k
And the above numerical values, the following relational expression holds.

φ∝Va / ▲ D ² ₂ ▼ ・ u ₂ ψ∝Δp / ▲ u ² ₂ ▼ ηf∝Va ・ Δp / T ・ N k = ψ / φ ² k∝Δp / Va ² And the discharge port of the conventional blower The fan characteristic graph when the ventilation resistance of the air-conditioning duct B connected to is variously changed can be schematically drawn as shown in FIG. In this graph, the vertical axis represents the pressure coefficient ψ or the fan efficiency ηf.
However, the flow coefficient φ is taken on the horizontal axis. The graph D is a pressure curve showing the relationship between the air volume and the wind pressure, and the graph E is a fan efficiency curve showing the relationship between the air volume and the fan efficiency.

Further, the resistance curves F and G of the air conditioning duct B, which represent the relationship between the air flow rate and the wind pressure resistance, can be drawn on the graph described above based on the above relational expression. The graph F is a graph obtained in the heat and defrost air conditioning modes in which the ventilation resistance in the duct is large and in the ventilation air conditioning mode in which the ventilation resistance in the graph G is relatively small.

The intersection points a and b of the pressure curve D and the resistance curves F and G
Are operating points that represent the respective operating states of the blower.
In this case, in the heat and defrost air conditioning mode in which the operating point a is located in the region where the flow coefficient φ is relatively small,
The fan efficiency ηf reaches the level shown by the point C close to the top of the fan efficiency curve E, and almost the maximum fan efficiency is obtained, while in the ventilation air conditioning mode, it is considerably low shown by the point d. Only level fan efficiency can be obtained.

On the other hand, regarding the air conditioning apparatus in which the air conditioning duct B is connected to the discharge port of the blower A incorporating the means for increasing / decreasing the air channel divergence angle in the scroll casing, the divergence angle in the downstream region of the air channel is 5 ° and 7 °. When a fan characteristic graph similar to the above was drawn by setting the above two settings, the graph shown in FIG. 8 was obtained.

Graphs H, I, and J are a pressure curve, a fan efficiency curve, and a resistance curve, respectively, which are drawn when the air passage divergence angle is 5 ° and the heat or defrost air-conditioning mode is set, and the operating point is at e. To position.

Graphs K, L, and M are a pressure curve, a fan efficiency curve, and a resistance curve, respectively, which are drawn when the ventilation path air-conditioning mode is set with the airflow divergence angle being 7 °, and the operating point is g. To position.

Here, comparing FIG. 7 which is a fan characteristic graph of the air conditioner with the above-mentioned conventional blower and FIG. 8 as a fan characteristic graph of the air conditioner with the blower A according to the present invention, the following is compared. Such a clear difference emerges.

That is, the former exhibits almost the highest fan efficiency in the heat and defrost air conditioning modes as described above, but the fan efficiency is considerably reduced in the ventilation air conditioning mode, whereas the latter according to the present invention has a fan scroll. By setting the air duct divergence angle in the casing to 5 ° in the heat and defrost modes, the fan efficiency (point f) close to the maximum level can be obtained at the operating point e, and the air duct divergence angle in the ventilation air conditioning mode can be obtained. By changing to 7 degrees,
Even at the operating point g, a fan efficiency (point h) close to the maximum level can be obtained.

That is, in the heat and defrost air-conditioning modes in which the resistance coefficient k of the blower increases, the operating point is moved to a region where the flow coefficient φ is small in which the maximum fan efficiency is obtained by narrowing the divergence angle of the air passage, and vice versa. In the ventilation air-conditioning mode in which the resistance coefficient k is small, if the method of moving the operating point to a region where the flow coefficient φ is large in which the maximum fan efficiency can be obtained by widening the air-flow spread angle, any air-conditioning mode can be adopted. Blower A always
Can be operated with near maximum fan efficiency, achieving the intended purpose of the invention.

FIG. 6 shows the blower portion of the device of the second embodiment using the air duct spread angle adjusting plate having an assembly structure different from that of the first embodiment.

The main body portion of the air duct spread angle adjusting plate 3 is a rectangular plate bent in an arc shape as in the previous example, and a pair of upper and lower L-shaped engaging pieces 3a functioning as a hinge portion at one side edge thereof.
3b is integrally formed, and the plate 3 is engaged with the engaging piece 3a by inserting the engaging piece into the insertion hole 1d of the engaging piece formed at the base end of the bulging portion 1c of the fan casing 1. And 3b can be rotated in the plate surface direction with the fulcrum as a fulcrum.
The other side edge of the plate 3 is provided with a hole 3c for insertion of the wire 9 for remote rotation operation. The wire 9 is connected to the plate 3 by screwing a nut 11 into the threaded portion at the tip of the wire 9. To be done.

The fan characteristics of the blower A and the air conditioning duct B are determined by determining the length of the air passage spread angle adjusting plate 3 in the downstream portion of the slag-like air passage a of the air passage A. And it is determined based on the experiment according to the ventilation resistance.

Further, regarding the shape design of the plate for assembling the airflow divergence angle adjusting plate 3 in the fan casing 1 and the rotating means of the plate 3, various methods other than the above embodiment can be used.

In the above embodiment, the centrifugal blower A has its discharge port connected to the air inlet end 20a of the air conditioning duct B, but the duct B
It is also free to be assembled at any place between the air inlet end and the air outlet end of the.

Further, as a means for interlocking the air conditioning mode switching means and the air passage divergence angle increasing / decreasing means, the operation is controlled by an electric signal transmitted in accordance with the operation of the air conditioning mode switching means, instead of the remote operation wire shown in the figure. A motor or various actuators can also be used.

[Brief description of drawings]

1 to 5 show the first embodiment device, and FIG. 1 shows the plane of the blower with the upper casing removed, the operation panel of the air conditioner, and the divergence angle increasing / decreasing means of the air passage. The interlocking mechanism with the air-conditioning mode switching means is shown schematically. FIG. 2 is an exploded view of the blower, FIG. 3 is a schematic side sectional view of the entire apparatus, FIG. 4 is a side sectional view of the blower, and FIG. 5 is a plan view of the blower for explaining the divergence angle of the air passage. Is. FIG. 6 is an exploded view of the blower of the second embodiment device. FIG. 7 and FIG. 8 are graphs showing fan characteristics of a conventional blower and a blower according to the present invention, which are incorporated in an air conditioner for a vehicle, respectively. In the figure, 1 ... Scroll casing (fan casing), 2 ... Fan, 3 ... Airway spread angle increasing / decreasing means (spread angle adjusting plate), 6 ... Plate 3 stopper,
7-10, 45 …… Interlocking device, 9 …… Wire for remote operation,
20 …… Air conditioning duct, 20a …… Air inlet end, 32, 32 ……
Air-conditioning heat exchanger, 36 ... Ventilation outlet, 37 ...
… Heat outlet, 38 …… Defrost outlet, 34, 39-41
...... Air path switching damper, 50 …… Air conditioning mode switching means (air conditioner operation panel), A …… Blower, B …… Air conditioning duct

Claims (1)

[Claims] 1. A centrifugal blower having a scroll casing is incorporated, and a first vent for ventilation, a second vent for heat, and a third vent for defrost are selectively opened and closed. In an automobile air conditioner including an air conditioning mode switching means for switching an air conditioning mode, a divergence angle of an air passage for blowing air of the centrifugal blower that is arranged in the scroll casing and is large when the first outlet is opened. However, when the second outlet is opened and when the third outlet is opened, the air duct divergence angle increasing / decreasing unit that reduces the divergence angle of the air duct, and the air conditioning mode switching unit are linked to operate the wind. An air conditioner for a vehicle, comprising: interlocking means for operating the road divergence angle increasing / decreasing means.